“OVIDIUS” UNIVERSITY OF CONSTANTZA UNIVERSITATEA ......UNIVERSITATEA „OVIDIUS” DIN...

“OVIDIUS” UNIVERSITY OF CONSTANTZA

UNIVERSITATEA „OVIDIUS” DIN CONSTANŢA

“OVIDIUS” UNIVERSITY ANNALS

CONSTANTZA

Year XX

(2018)

Series: CIVIL ENGINEERING

ANALELE UNIVERSITĂŢII

„OVIDIUS”DIN CONSTANŢA

ANUL XX

(2018)

Seria: CONSTRUCŢII

2018

“OVIDIUS“ UNIVERSITY ANNALS - CONSTANTZA

SERIES: CIVIL ENGINEERING

ANALELE UNIVERSITĂŢII „OVIDIUS“ DIN CONSTANŢA

SERIA: CONSTRUCŢII EDITOR IN CHIEF:

Carmen MAFTEI, PhD, Eng., “OVIDIUS” University, Faculty of Civil Engineering,

124, Mamaia Blvd., 900527, RO., Constantza, Romania, phone +40-241-545093, fax

+40-241-612300 [email protected]

ASSOCIATE EDITOR:

Alin CÂRSTEANU, PhD, Eng, ESFM – National Polytechnic Institute, Mexico City,

Mexico

Konstantinos PAPATHEODOROU, PhD, Eng, Technological Educational Institute of

Central Macedonia, Serres, Greece

DEPUTY/ MANAGING EDITOR:

Constantin BUTA, PhD, Eng, “Ovidius” University, Faculty of Civil Engineering, 124,

Mamaia Blvd., 900527, RO., Constantza, Romania, phone +40-241-545093,

[email protected], [email protected]

EDITORIAL ADVISORY BOARD Hafzullah AKSOY, Istanbul Technical University, Istanbul, Turkey

Alina BĂRBULESCU, "Ovidius" University of Constantza, Romania/Higher Colleges of Technology, Sharjah, United Arab Emirates

Mihai Sorin CÂMPEANU, University of Agronomic Science and Veterinary Medicine of Bucharest, Romania

Alin CÂRSTEANU, ESFM – National Polytechnic Institute, Mexico City, Mexico Silvia CHELCEA, National Institute of Hydrology and Water Management, Bucharest, Romania

Anca CONSTANTIN, "Ovidius" University of Constantza, Romania

Carolina CONSTANTIN, "Ovidius" University of Constantza, Romania Christophe CUDENNEC, Agrocampus Ouest, Rennes, France

Petar FILKOV, University of Architecture, Civil Eng. and Geodesy, Sofia, Bulgaria

Mariana GOLUMBEANU, National Institute for Marine Research and Development "Grigore Antipa", Constantza, Romania

Adrian Mircea IOANI, Technical University of Cluj Napoca, Romania

Dorina ISOPESCU, "Gheorghe Asachi" Technical University of Iassy, Romania

Nikolaos KLIMIS, Democritus University of Thrace, Thrace, Greece Demetris KOUTSOYIANNIS, National Technical University of Athens, Athens, Greece

João Pedroso de LIMA, Universida de de Coimbra, Coimbra, Portugal

Teodor Eugen MAN, Politehnica University of Timișoara, Romania Adrian MARCHIS, Technical University of Cluj-Napoca, Romania

Milan MESIĆ, University of Zagreb, Zagreb, Croatia

Ioan NISTOR, University of Ottawa, Canada Ichinur OMER, "Ovidius" University of Constantza, Romania

Konstantinos PAPATHEODOROU, Technological Educational Institute of Central Macedonia, Serres, Greece

Biljana SCENAPOVIC, University of Podgorica, Montenegro Florin ȚEPEȘ, "Ovidius" University of Constantza, Romania

EDITORS

Mădălina STĂNESCU, Mirela POPA, “Ovidius” University, Faculty of Civil

Engineering, 124, Mamaia Blvd., 900527, RO., Constantza, Romania, phone +40-241-

545093

LANGUAGE EDITORS

Lavinia Alexandra Istratie MACAROV, Ovidius University of Constantza, Romania

TECHNICAL EDITORS

Geanina MIHAI, Cristina SERBAN, “OVIDIUS” University, Faculty of Civil

Engineering, 124, Mamaia Blvd., 900527, RO, Constantza, Romania

mailto:[email protected]



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ISSN 2392-6139 / ISSN-L 1584-5990

© 2000 Ovidius University Press. All rights reserved.



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Ovidius University Annals Series: Civil Engineering, Year 20, 2018 5

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

TABLE OF CONTENTS

Vertical Connections on the Construction Market.......................................7

A. Marichova

Improving the Partnership between the Participants in the Vertical Chain of

the Construction Market..............................................................................19

A. Marichova

Aspects on the history of observations and measurements in the Black Sea

coastal zone, rehabilitation projects and marine modeling issues...............31

C. Borcia

Validation of building energy modeling tools for a residential building in

Brasov area-ROMANIA.............................................................................43

L. Cîrstolovean, P. Mizgan

Analysis on Variability of Buzau River Monthly Discharges.....................51

C. A. Mocanu -Vargancsik, A. Barbulescu

Studies related to the biological treatment of wastewater within the

Wastewater Treatment Plant of Iași City.....................................................57

C.-C. Prăjanu, D. Toma, C.-M. Vîrlan, N. Marcoie

Modern concepts for constructive solutions in Dobrogea...........................65

G. Draghici, A. M. Maican

Determination of the basic force-displacement on the top in the case of the

structure with reinforced concrete frames P+6............................................73

O. F. Ţepeş, M. Dragomir

Determination of global efficiencies of variable speed pumps within water

supply systems...........................................................................................81

D. Toma, C.-M. Vîrlan, N. Marcoie

Use of modern technology to develop investment housing projects in

Iraq.............................................................................................................89

A.M. Teen, A. M. Grămescu

Behavior analysis of minarets at the destructive factors actions..............97

S. Suliman, A. M. Grămescu

6 Ovidius University Annals Series: Civil Engineering, Year 20, 2018

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Introducing environmental technologies in industrial fuel combustion

processes……………………………………………………………….....103

M. Ruscă, T. A. Rusu

GIS based flood flow assessment in small catchments for flood mapping in

Bosnia and Herzegovina.…………………………………..…………......111

B. Blagojević, S. Kovačević, B. Nedić, N. Lukovac, M. Mujčić

Localized irrigation system for Thuja Orientalis in intensive culture……119

Mădălina Stănescu, Constantin Buta, Geanina Mihai and Lucica Roșu

The theoretical foundation of the concept of "architecture and the built

environment education"………………………………………………..…127

Irina Cerasela Filip, Cosmin Filip

Ovidius University Annals Series: Civil Engineering, Year 20, 2018

DOI: 10.2478/ouacsce-2018-0001

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Vertical Connections on the Construction Market

Aneta Marichova

_____________________________________________________________________

Abstract – The specificity of construction as an economic activity and of the

construction product (goods and services) determine the existence of a complex

vertical chain of links, involving different actors, which they perform simultaneously

the function of the buyer of the product from a previous participant and vendor

product to the next participant. In practice, this means that in every unit of the

vertical chain construction firm as a buyer of resources and services can be

monopsony or oligopsony, on the other hand as the seller of the created product may

be in the role of a monopoly or oligopoly on the market. The aim of the study is the

analysis the model of a bilateral monopoly on the resource and product market, the

conditions of equilibrium and the behavior of the construction firm at the entrance

and the exit, taking into account the specificities of different segments of the

construction market.

Keywords – bilateral monopoly, construction firm-buyer, construction firm-seller,

imperfectly competition, monopsony, monopoly, perfect competition, vertical

connections.

_____________________________________________________________________

1. INTRODUCTION

The specificity of construction as an economic activity and the construction product

(goods and services) determine the existence of a complex vertical chain of links, involving

different actors, as buyers and sellers which create value at each stage of construction and

perform different tasks and functions (fig.1).

Fig.1 Vertical connections between the different actors involved in the construction process


In this vertical chain main subject and factor is the investor - the person, which

finances the entire construction activity own and credit funds. The investor may be public -

the state or municipalities, or private, physical person - companies, households. Public

investment in construction (mostly in infrastructure) depend to a large extent the

possibilities of the state budget to fund major building projects the country's priorities in the

given period, its fiscal policy and various political factors. Private investment in

construction depends above all expectations of economic agents for future economic

development, expected return from the construction object, the credit policy of the banks

and many other primarily psychological factors. Investments in construction are

investments in real capital, real assets, which means that they do not exist or rarely exist an

element of speculative capital. On the other hand however, often the investment solution

itself is speculative, resulting primarily from the impact of future expected factors risk

assessment and expectations of high returns over a relatively longer period of time.

The creation of each construction product starts with the determination of the

requirements, the preferences of the investor (client) regarding the construction site (area,

technology, terms, quality, and price). The expressed claims of each client are a function of

his knowledge for about what is being sought on the market, with what technology can be

realized. They find their place in the development of individual, unique construction project

(from the point of view of location, infrastructure, functionality, design, ecology, etc.),

which embodies the highly qualified work of architects and designers/constructors. The

created service-level project is re-supplied to the investor for corrections, changes and a

final decision (to start or to refuse realization),which is broken down by its estimate of

expected return, expected changes in economic conditions, expected changes in the market,

etc. Therefore, the investor is a buyer and the construction company is a seller (vendor) of a

service, commissioned an external investor. The contractor works with subcontractors to

whom it entrusts the execution of certain tasks for the realization of the final product. The

executive firm is now a buyer, and the sellers of the service are subcontractors. These are

usually small companies who perform separate activities in which they are specialized or

activities related to maintenance, repairs that are not of interest to large companies. The

creation and realization of the end product means that the investor and the construction

company are the sellers of this product to the end user (households, firms) [1].

At each stage of the construction process, construction firms - contractors and

subcontractors use, combine in a certain way (depending on the technology chosen)

different materials, labor, including the basic and most expensive resource - the land. They

incur costs for their purchase from the respective suppliers and generate revenue from the

product they sell. The volume of these costs and revenues is, in principle, a function of the

specifics of the activity performed. Therefore, the participants in the construction process

simultaneously perform the function of a buyer of a product from a previous participant and

a seller of the product to the next participant. This means that in every unit from the vertical

chain of relationships construction firm as a buyer of resources and services can be

monopsony or oligopsony, on the other hand, as the seller of the created product may be in

the role of a monopoly or oligopoly on the market [2], which substantially changes the

behavior and conditions of market equilibrium.

Every participant in the chain searches, collects, analyzes different offers from

contractors and subcontractors, and chooses one to work with and control over its activities.

This costs each company significant transaction costs (external) [3], which influences the

formation of the final price of the construction product. These specifics of the construction

market require an in-depth analysis of the market activity of the construction firm at the

entrance and exit. In addition, the construction market includes different market segments,


both on the part of different buyers and their different behavior, both on the part of

companies, offering different construction activities with different geographic, territorial

locations. Every segment has a different number of buyers / sellers with different

characteristics, different behavior formed under the influence of various factors, and mainly

a function of the different competitive conditions, which determines their different market

power.

The aim of the study is to analyze the model of a bilateral monopoly on the resource

and product market, the conditions of equilibrium and the behavior of the construction

company at the entrance and exit, taking into account the specifics of the various segments

of the construction market, such as: 1) Assume, that the two markets --the product and

resource (factor) markets have a perfectly competitive structure, create an ideal market

outcome (effect)and deduce the conditions of equilibrium(determination of the equilibrium

price of the construction product and the equilibrium quantities), 2) With relevant structural

changes in the market/industry (product and resource markets are imperfectly competitive),

the behavior of the participants changes and, above all, buyers have a market influence that

changes the equilibrium conditions of the construction market.

2. THEORETICAL FRAMEWORK TO THE STUDY

In order to explore the real relationships and behavior of investors (clients),

contractors and subcontractors as buyers and sellers on the construction market, we will

accept the assumption that the two markets - the product and resource (factor) markets have

a perfectly competitive structure and create an ideal market outcome. As a result of

structural changes in the market/industry, the behavior of participants (buyers gaining

market influence) and market equilibrium conditions changes.

2.1. Equilibrium in perfect competition of product and resource construction market

Both markets have a perfectly competitive structure if the following conditions are

met:

1) A large number of companies compete to buy / rent a construction product (goods

and services) of specified quality, which is offered by many competing sellers.

2) Each company buys/rents only a small part of the total quantity available on the

market and is therefore unable to change market demand independently.

3) Every seller (vendor) of a construction product (goods and services) offers only a

small part of the total supply and is unable to have an independent impact on the

market supply.

4) Sellers of a construction product are free to enter and exit the construction market

and have the opportunity to transfer their resources from one way to another and

from one location to another in response to price dynamics.

5) The construction product which is sold in the relevant market is standardized in

the eyes of buyers.

6) The participants of the two markets are fully informed about the market

conditions, the prices and the quality of the construction product that is offered

and sought.

7) The participants of both markets are perfect competitors, which assumption is of

significant importance because demand in a market is a function of supply of

product creation in other markets.


On the perfectly competitive construction market total demand is formed by all firms

buyers a standardized construction product and the total supply is formed by the supply of

all firms- contractors, sellers of the given standardized construction product. From the total

demand and supply of the given standardized construction product, the equilibrium price

and the equilibrium price, which is fixed and no buyer or seller can affect it.

The construction firm-buyer and a perfect competitor on the construction product

market, aiming at maximizing profits to determine the optimum volume of construction

output it will buy, must compare the Marginal Revenue of Construction Product (MRCP)

that you will receive at the sale of the marginal/additional construction product with the

price it has to pay or with the transaction external marginal costs to conclude the deal with

the subcontractor and the purchase of the marginal additional construction product - -

MCCP (Marginal Cost of Construction Product).

The firm - a perfect competitor to the product construction market is the recipient of

the price of the created construction product, so that each unit of output, incl. and the last

produced/additional will be realized at the determined market price of the product РCP

(РCP - Price Construction Product). The proposed marginal construction product - MСP

(Marginal Construction Product) multiplied by the corresponding market price of the

product, will determine the marginal revenue of the buyer company: MRCP = MСP. РCP.

The marginal revenue from the construction product (MRCP) reflects the demand for

construction output by the respective buyer and is graphically depicted with a negative

slope search curve, because of diminishing returns to variable factor in a short run. At the

market-set, fixed price, it can buy an optimal volume of construction output following the

rule -equal marginal revenue with marginal transaction costs. If the marginal revenue

(MRCP) from the sale of marginal/additional construction product is greater than the

transaction costs the seller, the construction company will increase the volume of their

purchases, and vice versa - if the marginal revenue from construction product is less than

the transaction costs, it will reduce the volume of purchases (contracts).

The firm seller of construction product and the perfect competitor maximizes your

profits by striving to equalize the marginal revenue - MRCP from the sale of an additional

unit of construction output (equal to the price - РCP under perfect competition) with the

marginal costs - MCCP (equal to the average cost and product price) for its creation -

MRCP=MCCP. It determines the optimal volume of construction output it will offer and

sell at this current market price, following the rule - the market price of the product

(marginal revenue) is equal to the marginal cost of creating each additional unit product. If

marginal revenue, i.e. the cost - PCP is greater than the marginal cost

MRCP=РCP> MCCP,

the company has an interest in increasing the volume of the product offered and vice versa

- if MRCP=PCP<MCCP,

its interest dictates shortening the volume of the product offered (performed activities that

are negotiated with the buyer). Therefore, the curve of offering the sales company of

construction products in a market with perfect competition is the classic positive slope and

shows a right connection between price and supply volume of output. The equalization of

the total demand for construction products, determined by the marginal revenue from the

construction product - MRCP, which the buyer will receive and the total supply of

construction output determined by the seller's marginal cost - MCCP determines the


equilibrium price P*CP, the equilibrium quantities (Q*CP) and the equilibrium of the

construction market (р. E), where buyers and sellers are perfect competitors (fig. 2).

Fig. 2 Equilibrium in perfect competition of product and resource construction market

(buyers and sellers - perfect competitors)

2.2. Equilibrium in imperfect competition of product and resource construction market

The equilibrium conditions of the construction firm, which is both a buyer and a seller

in the vertical chain of links, are different when the product and factor markets are

imperfectly competitive. In economic theory are three models with different degrees of

imperfection.

The first model assumes that the firm has monopolistic impact of the product market

(mainly driven by product differentiation or economies of scale),but in the resource market

is a buyer-perfect competitor. The demand curve for its product has a negative slope, but

for each level of production, the price is higher than the marginal revenue (Pср>MRср) and

hence marginal revenue curve deviates under the curve of demand for the product. Since

the resource market has a perfectly competitive structure, total demand and supply of

resources form the equilibrium price. The company is one of the many buyers on this

market and it can not influence that price. With the current market price, the firm can buy

as much as it wants, following the rule - the marginal cost of each resource unit is equal to

the market price – MCср = Pср. Under the given conditions, the company - monopolist of

the product market buys fewer resources at the specified market price, and sells the finished

product at a higher price.

In the second model, the firm has a monopsony influence, i.e. there is only one big

buyer of resources (including labor). In an imperfect competitive structure of the resource

market, the supply curve of a resource (factor) is with the classical positive slope - if the

company wants to increase the resource purchases, it will have to pay a higher price. With

an increasing supply factor curve hiring an additional resource unitin creases overall costs

with a higher magnitude ,than the price increase because the higher price is paid not only

for the last unit purchased, but for all previously purchased resource units. It follows that

the marginal cost curve (reflecting the change in total costs resulting from hiring an

additional resource unit) for purchasing resources is growing and located above and to the

left of the supply curve or above average labor costs. In a monopsony market, the firm

realizes its monopsony power by purchasing less resources (defined by equality of marginal

revenue with marginal cost) at a lower price - MRCP=MCcp>Pcp, compared to a perfectly

competitive market.


The third model analyzes the behavior of a firm (seller) with a monopoly influence on

the product market and a monopsony influence (buyer) on the resource market, i.e. a

combination of the previous two. Under these circumstances, the market is in equilibrium

when the monopsony and monopoly company equals the marginal revenue from the end

product with the marginal cost of purchasing the necessary resources for its production.

Due to the monopolistic influence of the company on the product market the price of the

created product is higher than the competitive price and the demand quantity is lower. Since

demand for resources is a function of demand for the resource-produced product, and as a

result of monopoly-monopsony power, the price and quantity of resources purchased are

lower than the competitors.

3. APPLICATION THE THEORETICAL FRAMEWORK TO STUDY THE

VERTICAL CONNECTIONS IN THE CONSTRUCTION MARKET

3.1. Behavior of the construction firm with a bilateral monopoly on the product and

resource market

The most common model of the construction market is the model that implies a

market structure with two market participants, a monopoly on the part of the product

market, and a monopsony on the part of resource market. When a single seller (monopoly)

and single buyer (monopsony) collide on one market, the market structure is defined as

bilateral monopoly.

If the firm-buyer of a construction product is a monopsony and the construction firm-

seller has a monopoly impact on the product market, their behavior changes substantially:

1) The construction firm-seller that has a monopoly/oligopoly influence on the

product market, resulting from product differentiation, asset-specific differentiation or

economies of scale control this market and has market power, that allows it to impose and

maintain a price of the product offered higher than marginal revenue- PСР>MRCP. It will

seek to negotiate with the company-buyer the volume of output it has to perform for which

the marginal revenue is equal to its marginal cost of product creation (purchasing resources

and organizing production subject to the buyer's requirements in the contract)

MRСР=MCСР and a price - PСР,

at which to sell such output, higher than the specified equality

PСР>MRСР=MCСР.

2) The construction firm-buyer of the construction product is monopsonic market

impact. In this situation, its search for a construction product with certain characteristics

will be determined by the marginal revenue it will obtain from the realization of the product

at a later stage, but because of the monopoly position of the seller, the market price for each

quantity is higher than the marginal revenue for that quantity and therefore the marginal

revenue curve is below the demand curve (average income).

On the other hand, the firm –buyer and monopsony is facing a supply (in this case a

monopoly), which may itself and independently used in its own interest. It is well known

that within the monopoly market structure for the monopolist there is no uniquely defined

supply curve. Consequently, the marginal cost curve for production can also be seen as a


curve, identical to its supply (with a positive slope and an expression of average costs). At

the conclusion of the contract, the buyer is primarily interested in marginal (transactional,

external) costs incurred by the transaction and which will compare with the marginal

revenue from the realized construction product at the respective market price. Due to

monopsonic position the buyer company marginal costs are higher than the transaction

price (average costs) because the higher price applies not only to the last concluded

transaction but also to all previous ones) and the marginal cost curve of the monopsony is

above the supply curve of the monopoly.

3) The marginal costs and revenue allow determining the decisions the participants in

the deal should adopt in order to maximize their profits and achieve market equilibrium.

The monopsony as the only buyer in the market, maximizes the profit in point A (fig.3),

where equalize the marginal revenue from the construction product determined by the

demand for the product - MRCP with marginal costs - MCCP or MRCP=MCCP. The

optimal volume of construction output from the monopsony will be Q*ACP and the agreed

price (on the supply curve) will be set at P*ACP level.

The monopolist, as sole seller, maximizes its profit at point B (fig.3), where marginal

revenue MR equals with marginal costs МСCP (equal to average costs, product cost), or

MRCP=МСCP. From the positions of the monopolist, the optimal level of production

volume is Q*BCP, and the optimum price (lies on the search curve) is P*BCP.

Fig. 3 Equilibrium of the construction market with bilateral monopoly (monopsony buyer

and seller-monopoly)

The optimum price P*APS for buyer-monopsony determines the lower (lowest) limit

to which the market price of the resource may fall. It can only be achieved if the seller-

monopoly is forced to act as a perfect competitor. The optimal price P*BCP for monopoly -

selling is upper (highest) price limit that can be achieved if the buyer-monopsony is forced

to act as a perfect competitor.

The analysis of market behavior in this case can not give a single answer about what

the equilibrium price and quantity will be since the different objectives of the two parties

with market power on both markets can not be realized at the same time. Under these

conditions can only determine price limits (between P*ACP - P*BCP) within which the

negotiations will be conducted between the participants - the construction firm-buyer and

the construction firm-seller. The level of which will be determined agreed price depends on

the skills and strength to bargain the buyer and seller, as well as the specifics of the

construction market segment.


3.2. Vertical connections and behavior of the construction firm of various segments of

the construction market

On the housing market, demand is formed by households (as buyers of the product),

which are enough in each country, and at first glance can be attributed to the perfectly

competitive market of buyers. The new realities of this market show that consumers are

becoming more demanding, cautious in choosing and buying decision, informed in advance

of the company that builds and offers housing, about its history, its objects and ultimately

express more clearly their desires, preferences and impose their requirements for quality,

timeliness, correctness of the implementation of the signed contracts. Consequently, buyers

who form demand on the housing market can be identified as participants with increasing

market influence that can be bargained and impose better conditions upon conclusion of the

transaction (mainly price reduction on equal terms) [4].The growing market power of

buyers is the result of the following factors:

1) The large number of small construction companies that offer this market and

compete to win the buyer mainly through price discounts (price war).

2) Not very well expressed and understandable for consumers, the differentiation of

the construction product, therefore they tend and can easily switch and change one

company to another until they find an offer that best combines quality and price.

3) The high cost of purchasing a home and the high relative share of each household's

income lead to the purchaser's natural desire to reduce these costs.

4) The existence of a secondary housing market. These are old homes with well-built

infrastructure, which are also the object of sale.

5) The large volume of purchases of housing of "green" and the inability of some

construction companies to complete them for purely objective economic reasons or

phantom construction companies that simply collect buyers' money and disappear with

them. This creates uncertainty for buyers on this market and makes them particularly

attentive when making the deal.

The only alternative to the construction firm is to improve, develop and differentiate

its product and its business as a response to buyers' market power. The ability to

differentiate, distinguish its product transforms its users into customers with high loyalty,

which in practice means growing market power of the operating company and an

opportunity to impose higher prices on that market, considered over a sufficiently long

period of time.

On the market for non-residential customers of the product are usually several large

investors (foreign or private entities, often combined with large local firms) which form

oligopsony of this market segment. From a theoretical point of view, this means significant

market power and the ability to purchase smaller volumes of end product at a lower price.

Large investors (buyers) on this market have clear preferences and requirements for

the desired site (especially the construction of prestigious business buildings and retail

outlets), and usually work with several vendors on the basis of repeated contracts and

specifics of transactions [5]. The experience gained in these long-term relationships is a

guarantee for the realization of another site of the required quality within the set timeframe,

and this makes one of the construction companies a preferred partner with activity for years

to come. The effect of this specialization of companies is to differentiate the product and

turn it into a special, specific, unique product and growing monopoly power. The

monopsony power of the buyer, coupled with the monopoly power of the seller, offering

the unique, desirable product means that the objectives of the two parties with market

power can hardly be realized simultaneously and can hardly be given an unequivocal


answer to what equilibrium price and what equilibrium quantities will satisfy their interests.

It is certainly possible to set the price limits within which the negotiations will be

conducted. The output depends on the real market power and influence of the buyer or the

seller, but the specialization of the construction firm and its long-term stable relations with

the investor are a guarantee of its advantages in the negotiation.

On the market for civil construction has a clear buyer (monopsony) of a specialized

production and that is usually the state (or municipalities). As a rule, the seller on this

market is a large firm (monopoly) with differentiated assets and specialized in the

construction of such large objects or a consortium of domestic and foreign companies, who

earn announced tenders for public procurement. Besides the state, the buyer (monopsony)

of particular specific construction production can be also big companies with specialized

production, which usually work with one, also narrowly specialized firm in the construction

of the desired objects and the implementation of the necessary maintenance. In the case of

bilateral monopoly in both markets and unknown end result in terms of price and agreed

quantity (work volume), lasting relationships between the two market players can logically

grow in even closer relationships along vertical lines or vertical integration, by merging

companies involved in the chain. The vertical relationships thus created generally reduce

the monopoly power of the participants and increase economic efficiency.

Practice shows extremely tight and lasting connections that build between the buyer

and the seller on such a specialized market, which guarantees security and stability in both

countries' activities. In such a market, it is obvious that the interests of the two parties with

market power can hardly be realized at the same time. It is possible to determine the price

limits within which the negotiations will be conducted, but the outcome depends on the

actual market power and influence of the buyer or seller. The buyer's power must be

sufficient to prevent monopolistic price rise seller, but not too large to prevent the buyer

himself to fix monopolistic prices, when he will act as a seller of his own production.

Strong buyers can limit the market power of vendors in different ways - backward

integration, merging with suppliers or other competitors, mutual opposition of sellers. The

balancing power of buyers can lead to price reduction if some sellers even be aware of their

interdependence they do not have enough strength to unite and act together against the

separating policy of strong buyers.

4. CONCLUSIONS

The subject of the study in the proposed article is the links between the different

entities (investors/clients, contractors and subcontractors), which build a complex vertical

chain of links in the construction market. In this chain each participant performs

simultaneously the function of a buyer of the product from a previous participant and a

seller of the product to another participant. In practice, this means that in every unit of the

vertical chain has conditions for bilateral monopoly -construction firm as a buyer of

resources and services can be monopsony or oligopsony; on the other hand the output as a

seller of the created product can be in the role of monopoly or oligopoly.

To examine the real relationship and behavior of investors (clients), contractors and

subcontractors as buyers and sellers on the construction market, the author assumes first

that the two markets - the product and resource (factor) market have a perfectly competitive

structure and create ideal market outcome (effect). Equilibrium in perfect competition and

on the product and resource market is determined by the classic rule: equal marginal


revenue from the construction product, which will be received the buyer – MRCP with the

seller's marginal costs - MCCP which also determines the equilibrium price P*CP.

These conditions of equilibrium of the construction company that in the vertical chain

links is both buyer and seller are different when the product and resource markets are

imperfectly competitive. The construction firm-seller with a monopoly/oligopoly influence

on the product market will seek to negotiate with the company buyer volume output where

marginal revenue equals marginal cost of production MRCP = MCCP and sell this volume

at a higher price - PCP>MRCP=MCCP. The construction firm-buyer with a monopsony

influence on the market will seek to equalize the marginal revenue from the construction

product - MRCP with the marginal cost of the transaction MCCP, and purchase this volume

of output at a lower price - PCP<MRCP=MCCP.

Under the terms of a bilateral monopoly, it is impossible to determine precisely what

the equilibrium price and quantity will be as different purposes of the two participants with

the market power of the two markets can not be realized simultaneously. Under these

circumstances, it is only possible to determine the price limits in which the negotiations

will be held between the participants - the construction company-buyer and construction

company-seller. The level at which the agreed price will be determined depends on the

negotiation skills and buyer and seller power, as well as on the specificity of the market

construction segment.

Many large, small, equivalent sellers are operating on the housing market in an

effective monopoly competition. The large number of buyers (each household in the

country is a potential buyer in this segment) have an ever-increasing market impact and

opportunities for imposing conditions and prices on the conclusion of contracts.

Construction companies can respond to increasing market power to buyers by improving,

developing and differentiating their product and activity and creating loyal consumers.

In the market for non-residential construction, buyers are usually several large

investors - oligopsony, with significant market power. They almost always one-sidedly

define the parameters of the transaction and impose their requirements for quality, price,

timeliness of the projects and objects. The buyers (oligopsony) usually work with several

firm (sellers) based on repeated contracts, transaction specifics, and experience. The effect

of this specialization is the differentiation of the company's product and the increasing

monopoly power of the seller.

In the civil construction market, the buyer is always only one - the assignor, in the

face of various state institutions. This is a typical monopsony market with a large market

power that fully determines the operating conditions of construction companies. A seller on

this market is a large company (monopolist, which reduces the market power of the buyer)

with differentiated assets and specialized in the construction, which works with various

small contractors and subcontractors. In this case, a typical bilateral monopoly in both

markets the final result in terms of agreed price and volume of work is usually similar to

the ideal market outcome (effect) in the perfect competition, which increases economic

efficiency.

The overall conclusion of the author is that the different market segments, the buyer

and the seller have different market power, and the final market outcome (price / quantity)

depends on which of the parties will take leadership positions in pricing, although none of

the price options dictate prevents the realization of maximum aggregate profit. The buyer's

power must be sufficient to prevent monopoly increases seller’s prices, and the seller's

power must be sufficient to prevent monopsony high prices from the buyer, which is a

factor in increasing the economic efficiency of the market, and improving the relationships

between the participants in the vertical chain.


6. REFERENCES

[1] Myers, D. (2004), Construction Economics: A new approach. London. Spon Press, pp.

85-96

[2] Bridge, A., Tisdell, C. (2006), The Determinants of the Vertical Boundaries of the

Construction Firms, Construction Management and Economics, (22 /8), рр. 807-825

[3]Coase, R. (1937), The Nature of the Firm. Economica, 4 (16), pp. 386–405

[4] Galbraith, J. K. (1952), American Capitalism - The Concept of Countervailing Power.

Houghton Mifflin books

[5] Williamson, O. (1985), The Economic Institutions of Capitalism. New York, Free Press

__________________

Note:

Aneta Marichova - University of Architecture, Civil Engineering and Geodesy, 1, Hristo Smirnensky

Boulevard, 1046-Sofia, Bulgaria (e-mail:[email protected], marichova_fte @uacg.bg)


DOI: 10.2478/ouacsce-2018-0002

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Improving the Partnership between the

Participants in the Vertical Chain of the Construction

Market

Aneta Marichova

________________________________________________

Abstract – On the construction market the participants tend to work in the short

term and are limited rational using the accumulated knowledge and experience in their

practice. In addition, it is characterized by a low level of inter-company connections, i.e.

the same team seldom works together more than one project, resulting in a

fragmentation of responsibility. The complex relationships between the firms involved

in the vertical chain of value creation in construction objectively impose the need for

their improvement and more efficient management. The aim of the study is the analysis

the possibilities of creating a relatively stable relationship and a joint approach of

clients, contractors and subcontractors by deepening the specialization and

differentiation of each intermediate product, improving the quality of the final product,

optimizing the costs, creating a higher additional value at each stage of the chain and

ensuring economic, social and environmental performance of construction.

Keywords – construction firm, construction market, integrated vertical chain of

management, public-private partnerships (ppps), strategic alliances, vertical connections

and constraints, vertical integration

_____________________________________________________________________

1. INTRODUCTION

General trend in the development of modern economies is increasing role of the

market in the allocation and use of scarce resources. This means that the process is carried

out from private individuals, companies, which in their behavior are mainly guided by their

personal interest and the realization of higher profits. On the construction market,

participants tend to work in the short term, difficult to perceive innovations, and are

rationally limited by using the accumulated knowledge and experience in their practice. A

common feature is also the low level of inter-company relations, which means that the same

team rarely works together more than one project. In other words, each project involves

companies that are collected temporarily only for the realization of the project and specific

goals. At the same time, these firms are likely to be involved in other projects where they

coordinate their actions and allocate resources to other companies involved in the supply

chain. Each construction firm realizes simultaneously several different, individual projects

within the framework of its more widely defined mission and vision for development,

which requires coordinating its actions with other companies outside the scope of each

project.


The complex relationships between the firms involved in the vertical chain of value

creation in construction objectively impose the need for their improvement and more

efficient management. Unlike the construction market, other industrial activities are

characterized by relatively few independent elements and a much higher level of

coordination and management that allows the use of standardized procedures and products

and provides higher quality, improved management and economies of scale. This suggests

that the construction market is necessary improvement of the level of communication

between the participating companies, development of partnership, whether formally

through contracts or simply achieved through informal relations, which allow the creation

of multidisciplinary teams of investors, architects, designers, contractors, end-users at the

very beginning of the project. A partnership is required, which means a joint approach by

customers, contractors and subcontractors to optimize costs, create more value at each stage

of the chain, deepen the specialization and differentiation of each intermediate product,

enhance the quality of the finished product, which can provide economic, social and

environmental efficiency of construction.

Realizing this goal is far from simple, especially when there is no trust and effective

cooperation between the participants [1]. On the one hand, there is no commitment from

larger contractors to subcontractors for training, education, innovation development,

initiatives to improve organization and management of the activity, improvement of

working conditions and environmental protection. On the other hand, the subcontractors

(who actually carry out the projects) accept the projects they realize as prototypes, which is

why many of the problems that have arisen during the implementation of some projects are

not analyzed, but they are assumed to be normal functioning of the business. At the same

time, solving a problem, a task in a single project, can and should be passed as a positive

experience in subsequent projects. For this purpose it is necessary link between all

participants sharing experiences and multiply each had a positive effect. Gathering

information and revealing the essence of the problem can only happen with the active

participation of all employees in a given company and the other companies participating in

the vertical chain. Motivation and incentives for employees are a factor to overcome the

problem and create a more efficient organization.

Many of the problems are created by other participants at other stages of the

construction process, resulting from short-sighted vertical chain management and difficult

to remove from one firm. Contractors and sub-contractors do not want to recognize the

impact of their behavior on other activities and stages. As a result, the problems are solved

in a piece for the moment, which means high costs and inefficiency. Furthermore, there is

often a causal link between problems along the chain and solving a problem means

awareness of dependence and a common desire to overcome the problem through long-term

cooperation, which is rarely happening.

The construction market prevailing short-term contract, which means that the parties

have no interest in investing time and resources in such endeavors. Moreover, in the context

of a decline in construction activity, short-term contracts allow the contractor to rationalize,

optimize its activity by stopping it and reducing the number of subcontractors with which it

works. This policy does not provide sustainability of construction in the long term and

opportunities for quality improvement. These problems in the vertical chain of value

creation in construction, objectively indicate a need for improvement and more effective

management. The aim of the survey is: 1) analysis of the factors that influence the choice of

vertical relations by the construction firm, 2) analysis of the directions for development and

improvement of the relations between the companies participating in the vertical chain.


2. SELECTION OF THE VERTICAL RELATIONSHIP OF THE CONSTRUCTION

FIRM

Problems in the vertical chain of links in the construction market, the impact of

unfavorable factors make the seller and the buyer look for a relatively stable relationship.

The choice of vertical relationships for each firm depends on the nature of the relationship

between the firm and its partners (buyers and suppliers) and is determined by the frequency

and complexity of the transactions between the two parties (Fig. 1). Market transactions are

preferred for occasional or regular transactions, which are the subject of these transactions -

a product with common features. The specifics of the deal, the product subject of the

transaction and their increasing frequency itself as the most effective policy of vertical

integration. The integrated vertical control chain and the system of vertical connections and

constraints occupy an intermediate place but have a growing importance in company policy

and practice, both because of the higher end efficiency and because of the limitations and

control of vertical mergers imposed by antitrust law in each country.

Fig. 1 Selecting the vertical relationship of the construction company

The process of vertical integration is mainly aimed at uniting the successfully

functioning units of the production process into a single chain. Due to the specifics of the

construction market there are four types of transactions that make vertical integration

particularly effective [2]:

1) Transactions that require the use of specific assets by the seller or buyer. The

specificity of the company assets is one of the main motives for vertical integration. These

transactions include specialist vendor assets that are used only by a few buyers or physically

specialized, specific buyer assets that require specific resources provided by a small number

(often a single supplier) of suppliers and also the specialization and specificity of the human

resources used in a given production that are acquire only subject to the requirements of the

buyer.

2) Uncertainty of the deal, which makes control very difficult.

3) Asymmetry of information received by the buyer (when the resource provider

presents true but incomplete information to their partner).

4) Need for extensive coordination, which means high costs and time to realize the

goal.


The main reason for the vertical integration of companies is the increase in transaction

costs. Merging with subcontractors and/or suppliers and/or distributors reduces these costs

and turns them into internal company costs. In addition, control over important raw

materials can provide the company with competitive advantages over other companies that

are now denied access to this source of raw materials. Vertical mergers with feedstock

suppliers create prerequisites for increased costs for competitors' production or penetration

costs for new firms. Through the merger, the suppliers become employees of the company

which ensures their loyalty and reduces asymmetry of information. On the other hand,

vertical mergers of companies enable rhythmically to be supplied with vital raw materials,

better control over the quality of raw materials used, and reduction of production and

transport costs.

Most often, vertical integration with sellers (resource providers) or forward with

buyers leads to an increase in production capacity, technology competencies of the

company and creates opportunities for using and transferring larger cash flows between

individual enterprises and stimulating research and innovation. So large, leading

construction companies create complex holding structures, which bring together a large

number of subsidiaries, specialized in a particular activity from the different stages of the

construction process or in the production of a product for a particular market segment. This

is also proof of the high degree of horizontal integration achieved in them, which is an

important condition for their higher efficiency - achieved economies of scale, pooling more

financial resources and flexibility, adaptability to market changes. In addition, these

companies include in their structure and companies related to the investment activity, the

valuation and realization of real estates and of course the production and trade of building

materials. These processes of horizontal and vertical mergers cover the whole process of

vertical links in the construction market and reduce the monopoly power of suppliers and

buyers.

Because of the high resource intensity of construction activity, the construction

company links as buyers of building materials with its suppliers are particularly important.

The supply of building materials is carried out by several large companies involved in an

oligopoly structure (the concentration of this market reaches 60-70%) which are the active

part of the entire construction process. These companies realize significant economies of

scale and have high production potential, which is an important factor in reducing costs and

hence in raw material prices. In turn, construction companies (contractors and

subcontractors) also aim to reduce their costs (usually by around 20-30%) and the main

factor for the realization of this goal are the relations and relations with the suppliers of

materials. The relative share of materials used is about 40-45% of all construction activities.

This share is relatively smaller in maintenance and repair of buildings and facilities, and

significantly higher in the construction of new buildings and facilities. Construction firms

strive to provide timely, reliable supplies and receive materials, different components at a

lower cost, at best, favorable conditions for the payment of credit. Large construction

companies negotiate directly with large manufacturers or wholesalers at discounts for large

purchases. The highly concentrated market, with low competition between the suppliers of

building materials on the one hand, and on the other hand the less concentrated and higher-

performing construction market, gives the impression that strong suppliers exercise their

market power. Practice shows that the suppliers of building materials do not use or impose

a monopoly or oligopolistic power on the construction market. For these reasons, large

unions of suppliers of building materials and construction companies are rare in practice.

Large construction companies build their own production bases for building materials,

near the territory where they are localized, which provides them with stability, rhythmic


delivery and, most importantly, lower transaction and transportation costs. Vertical

alliances usually implemented such as large construction companies buy small companies -

manufacturers of building materials or are starting to develop their own business. Similarly

develops and integration forward with distributors, real estate agencies.

In today's conditions, the most effective form of development of vertical relationships

in construction that creates competitive advantages is the system of vertical connections

and constraints and the integrated vertical chain of management. The vertical connections

are relations of control and constraints in the activity of two independent, independent

construction companies, which participate in successive stages of the production process.

Vertical constraints help solve mismatches which derive mainly from asymmetry of

information. In a relationship between a buyer and a seller of a construction product,

asymmetric information can lead to the problem of "principal agent", which means one

company to realize the benefits of the other company without paying for it.

A particularly effective form of interaction between all companies involved in the

vertical chain of construction activities is the integrated vertical chain of management. It is

a network of firms, organizations, activities that engage in links - up and down in different

processes and create value in the form of end-user products and services. Thus, the scope of

chain management covers the production and supply of materials, the production of the

next product, the end product and its realization to the end user. Every participant in this

chain depends on the other participant and active cooperation is needed in order to achieve

higher efficiency. This cooperation is achieved through long-term relationships,

connections, seamless collaboration and information sharing.

Firms in the integrated vertical chain of management share information and

coordinate within the established chain, providing maximum benefit to all participants.

Furthermore determine accurate assessments for execution of transactions and to assess the

effectiveness of the chain. The final results in integrated vertical chains are an improvement

in customer service, reducing inventories throughout the chain, offering a better product,

realizing higher profits throughout the life cycle of the product and build a competitive

advantage for participating companies.

The integrated vertical chain of management implies competition with other chains,

not between companies, which allows achieving:

1) Higher efficiency of logistics, which includes planning, organization, coordination

and control over the performance of the obligations of each participating company. The

basis for this is the permanent links and the exchange of information between the

participants - the construction firm-buyer and the firm-seller (contractor, subcontractor or

supplier of building materials).

2) Establishing long-term partnerships between all participating companies based on

common interest and good personal relationships, which is factor for joint problem solving,

information sharing and risk. In view of the good end result, the active participation of

suppliers of building materials is particularly important throughout the process - from

design to realization of the object together with the construction contractor. This reduces

costs by up to 10% and increases productivity.

The basis for effective joint work in the integrated vertical chain is trust. Effective

connections between all participants combined with effective management of all units of

the vertical chain with other good practices of customer relationship management ensures

greater competitiveness on the market and allows creating a high quality, differentiated

product with specific features desired by customers, as well as a reduction in production

costs and the price.


3. GUIDELINES FOR DEVELOPMENT AND IMPROVEMENT OF THE LINKS

BETWEEN THE FIRMS IN THE VERTICAL CHAIN

One major opportunity to improve the links between the firms in the vertical chain

and especially for the development of the small subcontractors is to unification with other

companies and create strategic alliances. They are defined as "voluntary partnerships

between firms on the basis of contractual relationships that allow for development and

change through cooperative production and the development of the end product created

through the transfer of technology, knowledge and services" [3], with the participating

companies retain their relative independence in the time of its existence, i.e. are practically

excluded and no merger and takeover processes are observed.

Strategic alliances can be realized both between companies that are equal partners and

between companies with different market positions and potential [4]. If a small company

participates in a union with a big, established firm on the market, it gives it access to the

experience of the big ones, to the "good practices", the opportunity to improve the internal

organization, to improve its activity, to expand the knowledge and to create a new, allowing

initiate necessary changes. The creation of an alliance involving small, medium, equivalent

firms limits the potential, reduces the flexibility to the dynamics of the environment and

their future development. A small business has a chance to succeed if it participates in a

strategic alliance where other actors have innovative capabilities and therefore the potential

for technological and market change.

If for small business players in such a system the result is a better business and

learning of "good practices", for big, key players, building these relationships is an

opportunity to realize economies of scale and / or economies of scope, reducing switching

costs associated with choice of suppliers and other contractors, which stimulates the

development of innovations in a product, technology, and allows the creation of a higher

added value for customers and thus the realization of higher profits. An important factor in

achieving the desired success, greater than the success that can be realized in each

individual company taken or a synergy effect is the realization of the necessary control and

coordination of the overall activity.

The links in the strategic alliance are developing on the activities of the included

firms that create separate parts, elements, components of the final general product. The

company leader, a key player, sets the standards, the product requirements created at each

stage of total production. Under these conditions, the small company must develop and

deepen its specialization and differentiation of the created product. Realizing a common

objective requires maintenance of formal and informal links between different companies

and personalities based on the generic resource created by acquiring different assets. A key

success factor is access to information, experience and their exchange in order to solve

current problems. Building effective links at all levels, formal and informal, the trust

between all subjects is critical for each union (fig.2).

The unification between companies can to ensure a more efficient allocation and use

of scarce resources, the realization of a synergistic effect in one or more companies,

successful adaptation to external changes, through know-how, knowledge sharing,

information, technology and products, which in turn increases the productivity and

effectiveness of vertical links.

Another major direction to improve the performance of the construction company and

the effectiveness of buyer-seller relationships, especially in the civil construction market,

where the buyer (state and municipalities) has a strong monopsony power is the

development of public-private partnerships (PPPs). The need for higher efficiency of the


public funds used, coupled with the increasingly limited budget opportunities, require

reorientation of the state from a policy of acquiring assets to a policy of getting a service. In

practice, this means involvement of the public sector in the overall process of design,

construction, financing and exploitation at shared risk between the public and the private

partner.

Fig. 2 Strategic Alliances

Traditionally, the state finances the construction of infrastructure as a threat to the

realization of the object of a company contractor. After completion of the construction

works the state is committed to the maintenance and operation of the sites, taking all risks,

related to the construction and operation of these sites- higher prices than forecast, quality

control, execution on time, etc. PPPs is a long-term contractual relationship between private

and public sector entities for the financing, construction, reconstruction, management and

maintenance of infrastructure in order to achieve a higher level of service, with the private

partner assuming the risk of construction and at least one of the two risks associated with

the availability of the service or its search. Payments for the service provided by the private

partner are bound by its quantity and quality and the state reduces its payments when

providing a different service of the desired quality and quantity. PPPs offers and provides

the necessary quality of public service because:

1) There is a holistic approach to the design, construction, and exploitation.

2) Payments from the state are after providing the desired service in the desired

volume and quality, which means that it is without obligations in the construction phase.

3) Risk-sharing between participating partners means that the state transfers to the

private partner the financial security risk and the construction of the site and it remains the

risk of ensuring the demand for the service offered, with which to cover the costs of the

investor.

4) PPPs actively use private resources and experience which provides effective use of

resources within the set budget and time of realization of the site.

Firm - a key player

Other firms participating in the

Alliances

Strategic Alliances

Dynamics of the

external

environment

Integration

Coordination

Training, Assimilate

new knowledge

Innovation,

technological change

Experience of

joint programs

Competitive advantages

Stable market positions

Performance

Development of

specialization


The basis for the successful operation of the PPPs system is to ensure a better, higher

value of the public funds, defined as Value of Money, by carrying out full control and

analysis of the costs and benefits of the project. The assessment is made using quantitative

methods that determine the net present value (NPV) and a qualitative analysis of the

project's economic efficiency. This quantitative and qualitative assessment of the service is

compared with a benchmark, called comparable public expenditure (CPE). CPE includes all

costs, also in line with risk, if the site is implemented by the public sector. If the net present

value (NPV) is higher than the comparable public expenditure (CPE), the realization of the

object of PPPs is more efficient and gives higher Value of Money. The realization of this

higher value (Value of Money) is primarily the result of innovative private partner searches

and the optimization of the overall design and construction cycle. Especially important is

the problem of conducting transparent tender procedures and making a mechanism for the

determination of net present value (NPV) and comparable public expenditure (CPE) and

their comparison.

PPPs system must be supported by well-developed and working mechanism for

making payments, which may be direct charges paid by users, hidden fees (the state pays to

private partners and the source of the money is paid by all citizens) or all costs are borne by

the state and it allocates payments for the entire period of the contract concession. The state

must take the risk of demand differently than expected (greater or less) and to compensate

for the risk assumed by private partners increasing additional payments at lower demand

and vice versa. The creation of PPPs also requires active participation banks, consulting

firms, with the help of which to define the structure, the relationships of the actors involved

and to share the risk.

As world practice shows, the benefits of PPPs are associated primarily with the

proposed lower price, higher quality and timeliness of the performance of the objects,

realized by private partners, which increases the efficiency of the vertical links in the

construction and minimizes the risk. PPPs combine innovation, experience and business

sense of the private sector with the ever-increasing need a good infrastructure of public

sector which ensures higher profits for private companies and higher efficiency for

taxpayers.

A more effective partnership between the public and private sectors can also be

realized by creating a construction cluster, which includes interconnected

companies/subjects, involved in the vertical chain of created value - construction company

with strong positions - leader or anchor, investors, suppliers of construction equipment, raw

materials, architectural and design offices, contractors and subcontractors, distributors,

marketing and advertising agencies, state and local public institutions, universities, research

units, construction (branch) organizations, each with specific rights and obligations (Fig. 3).

Clusters are geographically concentrated associations (region, state, or even a city, and may

be extended to neighboring towns, regions, or even neighboring countries), which primarily

recognize the priority of education and research and provide specialized training, education,

information, research, technical support of the participating firms and whose activities as a

whole are developed on competition and cooperation [5].

The efficiency of clusters is due to the applied integrative approach to various

activities, projects that are interconnected, complementary. The main factor ensuring the

efficient functioning of the construction cluster is the availability of a basic, leading

company (often called anchor), well-built infrastructure, and access to markets, raw

materials, social services and financial resources. Most cluster participants are not direct

competitors, they work on different market segments, have common problems,

opportunities and threats in their business. Practice proves that the success of the cluster is


primarily a function of the development and use of intangible assets (innovation,

knowledge and education) that are the basis for building an effective system of inter-firm

relationships on trust. Opportunities for coordination and mutual improvement of activity in

each cluster reduce the risk of ineffective competition or limiting the intensity of rivalry.

The realization of these processes depends to a great extent on the built personal

relationships, communication and networks of private persons and institutions. Close links

with buyers, suppliers, and other institutions are an important factor for the realization of

competitive advantages company goals, while at the same time the system does not exclude

competition between participating companies, on the contrary- it implies. Especially

important is the availability of an educated workforce, proximity to research, higher

education, an entrepreneurial spirit and culture that values education and knowledge. These

services must be provided by public institutions.

Fig. 3 Construction Cluster

The public sector plays the role of an intermediary between participating private

firms, a role of initiator of programs and concrete implementation plans, a listener of

problems that need to be quickly mastered and resolved. Public institutions at national or

local level have three main objectives:

1) Ensure cooperation, interaction and equality to all actors involved and to create

conditions for a strategic partnership.

2) To maintain the necessary infrastructure - transport, social and opportunities for

permanent development, training and raising the qualification of the required workforce.

3) Ensure coordination of the different programs and funding of interconnected

activities, not individual activities and projects that are isolated from one another.

Contractors

Construction cluster

Organization and management

of the construction process

Construction firm -leader

(anchor)

Architects and

designers

Subcontractors

Suppliers of

raw materials

Suppliers of

equipment

Construction

small firms

Clients/

End users

Investors

Production of

raw materials

Production of

equipment

Advertising

(Internet)

Laws,

regulations

Universities,

Research Units

Public

institutions

Labor and land

market firm

Brokers

Financial

institutions


Interaction, cooperation and competition with all participating companies in the

construction cluster requires the creation and implementation of new business models,

where specialization, the development of open innovation of the company and its co-

operation with other interconnected and complementary companies and assets are central.

The creation of the construction cluster facilitates the creation of an effective integrated

vertical link system, because it includes from related and supporting the main production

activities, "from the development of innovation and the idea to its realization".

4. CONCLUSIONS

The object of study in the article is the complex relationships between the companies

participating in the vertical chain of value creation in the construction. The construction

market has ineffective vertical links between the participating companies as they tend to

work in the short term, there is a low level of cross-company relationships, meaning that

the same team rarely works together more than one project and is usually absent among the

participants trust. On the one hand, there is no commitment of larger contractors to

subcontractors for training, education, development of innovation, initiatives to improve its

organization management of the activity, improvement of working conditions and

protection of the environment, and on the other hand, the subcontractors (who actually

realize the objects) accept the projects they realize as prototypes without analyzing and

solving any problems. The problems show that it is necessary link between all participants

sharing experiences and multiply each had a positive effect.

The final construction products which are in demand by consumers are a complex

system of different elements, components, parts with strong functional dependence, which

to a large extent defines and the need for unification between most independent firms in a

vertical chain, and is a factor for the application and development of best practices in the

field of design, construction, maintenance and reconstruction.

There is a need for partnership, which means a joint approach of clients, contractors

and subcontractors in order to ensure the economic, social and environmental efficiency of

the construction. In modern conditions, the most efficient form of development and

improvement of vertical relationships in construction is the integrated vertical chain of

management. Integrated vertical chain management is based on competition and includes a

network of companies, organizations, activities that cover the entire construction process

(from production and supply of materials, the production of various intermediates, to the

creation of the final product and its realization) and create value in the form of end-user

products and services. Efficiency is achieved through cooperation and long-term contracts,

long-term relationships, links, continuity of collaboration, information sharing and trust.

The establishment and effective management of an integrated vertical chain of links and

competitive relationships is an important factor in stimulating innovation, especially "open

innovation", reducing information asymmetry and transaction costs, increasing

specialization, developing technology inside and outside the company and their use in

creating the final construction product.

According to the author, the main guidelines for development and improvement of

links between firms in the vertical chain are related to building strategic alliances,

construction clusters, development of PPPs, or simply informal relationships that allow the

construction of multidisciplinary teams right from the beginning of a project, whose main

purpose is to create an object corresponding to high expectations consumers and society,

i.e. the requirements of sustainable construction. In the traditional approach of designing,


uncoordinated work of the various actors leads to permanent corrections and sometimes the

necessary changes are noticed too late when started construction itself and removing them

can be much more expensive. Therefore, the improvement of vertical links and

coordination should start from the earliest stages of the project and require the application

of integrated design principles (the approach to completed building systems)which means

responsible commitment of all participants in the process from beginning to end: investors

and clients, architects, constructors, designers, contractors and subcontractors, suppliers of

raw materials, administrative authorities, lawyers, researchers, which in practice means

substantial changes in the organization, coordination and management of the construction

company at all levels and its vertical relationships.

5. REFERENCES

[1] Myers, D. (2004), Construction Economics: A new approach. London. Spon Press

[2] Williamson, O. (1985), The Economic Institutions of Capitalism. New York: Free Press

[3] Gulati, R. (1998), Alliances and networks. Strategic Management Journal, Vol. 19, рр.

293–331

[4] Iansiti, M., Levien, R. (2004), Strategy as Ecology. Harvard Business Review, Mar

(82), рр. 68-78

[5] Porter, M. (1998), Clusters and the new economics of competition. Harvard Business

Review, Nov/Dec. 98. Vol. 76, Issue 6, pр.77-90

__________________

Note:

Aneta Marichova - University of Architecture, Civil Engineering and Geodesy, 1, Hristo Smirnensky Boulevard, 1046-Sofia, Bulgaria (e-mail:[email protected], marichova_fte @uacg.bg)


DOI: 10.2478/ouacsce-2018-0003

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Aspects on the History of Observations and

Measurements in the Black Sea Coastal Zone,

Rehabilitation Projects and Marine Modeling Issues

Constantin Borcia

_____________________________________________________________________

Abstract – Over time, the content, scope and objectives of hydrological research

in the Romanian Black Sea coastal area varied according to the state of society

development, technology development and financial resources. Along with the

activities of capitalizing on natural resources, water use, river and sea navigation,

there have been demands for knowledge of the water regime and the interaction

between the resource potential and the characteristics of the hydrological regime. As a

result, hydrographic and hydrological research was started and developed in the

Black Sea coastal zone. These researches developed in the first half of the nineteenth

century, and then continued throughout this century and later in the twentieth

century, with interruptions caused by the two world wars. Among the important

activities that have taken place over time, there have been hydro-technical works. The

design and elaboration of the projects of these works were based on the knowledge of

the hydrographic and hydrological characteristics of the Black Sea coastal zone. This

knowledge has evolved over time so that there is currently an important pool of data

and information related to the hydrological, morphological, hydrochemical,

hydrobiological characteristics of the water bodies mentioned.

The paper presents briefly the most important moments of the history of the

monitoring activity carried out over time in the Black Sea coastal zone, the types of

coastal and transitional waters in Romania, coastal rehabilitation projects of the

Black Sea, hydrological features, the structure of the marine complex model pom /

ersem III) BREG / BSHELF.

Keywords – coastal area, monitoring, hydrological features, rehabilitation projects,

marine modeling.

_____________________________________________________________________

1. INTRODUCTION

Historical knowledge is very important in any field, including in the hydrological field,

and if this knowledge is ignored or minimized, then all planning or prognosis will suffer.

In connection with the history of monitoring activities carried out in the Black Sea

coastal area, several works have been written over time, which are now rarities.

Examples are: - Grigore Antipa, - "Black Sea" - vol. 1 "Oceanography, Bionomy and

General Biology of the Black Sea", Romanian Academy, Fundatia Vasile Adamachi,

TOMUL X, Nr. LV, 1941; "The Danube Sinking Zone, Hydrological Monograph" (edited


by Diaconu C., Nichiforov I.D.), CSA, Bucharest, 1963; "The Black Sea in the Romanian

Seaside Area - Hydrological Monograph", (editorial collective, edited by Bondar C.), 1973,

IMH, Bucharest.

At international level, there are a number of oceanographic and marine numerical

studies and models developed by various oceanographic institutes: MEDATLAS - a marine

climatic model with application, especially for the Mediterranean; General Ocean

Turbulence Model (GOTM) - is a 1-dimensional numerical model for simulating vertical

exchange processes in the marine environment; MOM - Modular Ocean Model; Pollutant

Routing Model, US-EPA; POM - Princeton Ocean Model; SCRUM-S Coordinate Rutgers

Model; The GFDL Modular Ocean Model; WAVEWATCH Model; WWW Tide and

Current Predictor; ASGAMAGE - ecological model (1, 2, 3 - dimensional) for simulating

carbon dioxide exchanges CO2, helium He and SF6 sulfur hexafluoride, using ocean edge

edge element, ERSEM - marine ecological model. Marine marine patterns for the Black Sea

were developed for example by Bulgaria and Russia. At the national level, there is no

significant numerical model for the Romanian Black Sea coastal zone. As a result, an

Italian - Romanian cooperation program was launched in March 2003 on the

implementation of an integrated Western Black Sea environmental system - WBLESS. One

of the objectives of this program was the realization of a complex physico - ecological

numerical model. The model is currently incomplete. In order to be complete, it is first

necessary to establish the limit conditions, then the monitoring data implementation

program and, finally, the testing or calibration of the model.

2. HISTORY OF OBSERVATIONS AND MEASUREMENTS

The Black Sea began to be studied before other seas. In the 5th century BC, the Greek

historian Herodot visited the northern shores and described the nature and the climate by

naming a few rivers flowing into the sea in these areas.

In the third century, the first map of the Black Sea was drawn up. Ptolomeu

commemorates cities, sea promontories and astronomical dots. Later on, the Genoese

developed nautical maps and improved sea maps (Visconti's map of 1311).

In 1822, on the basis of the coastal data of the French, the first Black Sea map

appeared in Paris. From the chronicles of the times we learn that the first observations and

measurements on the Black Sea date back to the 14th century, during the reigns of Mircea

the Elder and Stephen the Great. The first scientific studies related to the Romanian

territory date back more than a hundred years and were determined by the maintenance of

the navigation through the mouths of the Danube and the arrangement of the port of

Constanta. These objectives led to the first approach to the knowledge of the

meteorological characteristics (establishment of the first meteorological stations Sulina

1857, Constanta 1860), the study of the influence of the Danube alluviums, the study of the

sea currents and the waves, as well as the knowledge of the structure of the Romanian

seaside. The first hydrographic map of the Romanian coasts (scale 1: 20000) (Antipa, G.,

1941, Fig. 1) appears in 1901 (based on plans and maps drawn up by French and British

engineers and geographers after the Crimean War) and in the following years other maps

have been executed.

In 1903, Stephen Hepites signed the first synthesis of the climatic elements at Sulina.

In 1930, a great pioneer of Romanian oceanography, after Emil Racovita, Grigore

Antipa founded the bio-ecological institute in Constanta (today named after him). Since

1926, the Military Navy Hydrographic Service and the General Directorate of Ports and


Waterways have begun to carry out hydrological measurements and observations at the

mouths of the Danube and on the Romanian Black Sea coast. From 1928, under the

direction of Commander P. Fundateanu, "Marine Magazine" appears on the study of

currents, density, temperature and alluvium in the mouth of the Danube mouths. In 1941,

the "Black Sea" monograph, drawn up by Dr. Grigore Antipa, appeared. Starting with 1959,

albums and oceanographic directories appear. But the extended systematic activity on the

problems of sea physics began in 1960, then 1967 by the establishment of oceanographic

research stations Constanta, respectively Sulina.

Fig. 1 Bathymetric map of the Black Sea (1901 - after the polls of the Russian expedition

Spindler and Wrangler - archive, reproduction document

Another reference work in this field is the "Black Sea in the Romanian Seaside Area -

Hydrological Monograph", responsible editor, dr.ing. Constantin Bondar.

The institutes investigating the Romanian Black Sea coastal zone are: INCD Geology

and Geoecology Marine (GEOECOMAR), National Institute for Research and

Development Marine "Grigore Antipa" Constanta - Romania, National Water

Administration - Water Directorate Dobrogea Litoral.

3. TYPE OF WATER AND TRANZITOR WATER FROM ROMANIA

According to one study [2], the coastal area was framed as follows:

'Coastal waters' means the surface water from within to the dry land of a line, each

point of which is at a distance of one nautical mile from the nearest point of the baseline

from which the breadth of territorial waters is measured, which (if necessary) can be taken

up to the outer limit of the transitional waters.

"Transitional waters" are surface waters in the vicinity of rivers, which are partly

saline as a result of proximity to coastal waters but which are substantially influenced by

freshwater flows.


The types of coastal waters in Romania

The coastal waters of the Romanian Black Sea sector extend from Periboina to Vama

Veche (the border with Bulgaria); continues with the coastal waters of the Bulgarian Black

Sea sector.

According to the specific criteria of the two systems A and B, the following

typological classification of coastal waters in Romania is accepted Table 1:

Type RO90 - Short sandy coastal waters with sandy substrate on the central

seaside area of Periboina to Cap Singol.

Type RO91 - Deep coastal waters with mixed substrate (sand with rock

formations), on the southern sector of the Romanian seaside, from Cap Singol to

Vama Veche.

Table 1. Typology of coastal waters in Romania

Type Name Depth Substrate

RO90

Deep coastal coastal waters with sandy

substrate

(from Periboina to Cap Singol)

small Sand

RO91

Deep coastal water a little deep with

mixed substrate

(from Cap Singol to Vama Veche)

small Sand with island

rock formations

Types of transitional waters in Romania

Transitional waters extend across the entire Romanian Black Sea sector from Chilia to

Vama Veche, both in the terrestrial area (like river and lake waters) and in the seaside

maritime area (as seas).

According to the specific criteria of the two systems A and B, the following

typological classification of the transitional waters in Romania is accepted (Table 2):

Type RO80 - Transitional river waters, on the Danube's Black Sea springs.

Type RO81 - Transit waters, lakes in the central and southern terrestrial area of

the Romanian seaside.

Type RO82 - Transitional Marine Waters, in the northern sector of the Romanian

seaside, from Gura Chilia to Periboina.

Table 2. Typology of Transitional Waters in Romania

Type Name Depth Substrate

RO80 Transitional river waters

(the Danube springs) small sandy

RO81 Transient lake waters

(coastal lakes in the terrestrial area) very small sandy

RO82 Ape tranzitorii marine

(de la Gura Chilia la Periboina) small sandy


4. PROJECTS FOR REHABILITATION OF THE BLACK SEA COAST AREA

Coastal rehabilitation projects include the W-BLESS project, Integrated Coastal Zone

Management and the JICA project.

• The W-BLESS project - "W-BLESS - Western Black Sea Integrated Environmental

System" and "Integrated Environmental System for the Western Black Sea" initiated in

March 2003, being a forward-looking Italian-Romanian project . It is a feasibility project

and has several tasks, including:

- Monitoring system - modeling for the Romanian Black Sea coastal zone:

- Integration of the river basin into the management system.

- Identification of sources of pollution and analysis of anthropogenic impacts on

large-scale basin water.

- Recognize existing basin infrastructure.

- Classification of insured goods from the environment and services.

- Fixing the monitoring network for the qualitative and quantitative control of water

and soil.

- The overall infrastructure plan of the most sensitive water sectors to environmental

requirements.

- Simulate impacts from infrastructure investments.

- Securing bank and financial resources.

• Coastal Zone Management - Integrated Coastal Zone Management consists of a

decision-making cycle that includes horizontal integration (ie integration of coastal

geographic units and co-ordination after different sectors) and vertical integration (ie

coordination and communication at different levels of government).

Integrated management includes several systems, including:

- the natural system (which includes non-human domains, namely the atmosphere, the

lithosphere, the hydrosphere as well as the dynamics and their interactions in the

abiotic and biotic processes and which exist outside the human presence;

- functional users (represents the set of human interests in terms of "users" of the

natural system, respecting the users of the natural resourses);

- the control system (the use of functions is governed by, for example, the natural

system is guided by infrastructure, in many cases control is necessary, because if it

is not present, different stresses and conflicts may emerge).

The JICA project - this project concerns the protection and rehabilitation of the

Mamaia Sud and Eforie Nord areas, as well as the Năvodari and Vama Veche areas.

The Ministry of Environment and Water Management, with the support of the JICA

International JICA Agency, initiated the project "Study on the Protection and Rehabilitation

of the Southern Part of the Romanian Black Sea Seaside". The study aimed at:

• elaboration of a protection plan for the southern part of the Romanian seaside;

• carrying out preliminary actions to promote preliminary projects;

• transfer of knowledge and technologies in the field of coastal protection and

management to the Romanian side.

The priority areas were established as: Mamaia Sud, Constanta Nord, Eforie Nord,

Eforie Sud and Costinesti.

The works are: rehabilitation of dikes, creeks and episodes, artificial reefs, sanding,

decommissioning of existing works etc.; total investment value: 316,000,000 Euro

(according to data http://www.mmediu.ro).


5. SOME METEOROLOGICAL AND HYDROLOGICAL CHARACTERISTICS OF

THE BLACK SEA ROMAN COSTIAN ZONE

• Wind direction. On the Black Sea Romanian seaside air transport in the cold

season takes place from the north and north-northwest, and in the hot season in the north

and north-east. The average annual transport has a speed of 0.9 m / s at Sulina and 0.7 m / s

at Mangalia, having the north - northeast direction. The average wind speed in the cold

season is about 8 m / s in the western and northeastern seas, and the south-eastern part of

the average wind speed decreases a lot in the cold season as well.

For example, the variability of the wind frequency over four consecutive years, as

well as the frequency of calm (percentages) (Fig. 2).

Fig. 2 Frequency (%) of wind direction - s.h. CONSTANTA METEO, 2014, 2015, 2016, 2017

• The air temperature regime on the Romanian Black Sea coast is characterized by

the existence of a thermal gradient from north to south from September to March and from

south to north from April to August.

• Levels, currents, waves. The Black Sea Levels on the Romanian seaside - the

maximum amplitude of the variation in levels reaches 169 cm in Sulina (sea), 190 cm in Sulina

port, 117 cm in Constanta, 129 cm in Sfantu Gheorghe port and 116 cm at Portiţa Mouth.

For example, Fig. 3 shows the variation and trends of the average, minimum and

maximum annual levels for the period 1858-2016 per s.h. Sulina Lamp Signal (multi-

annual average levels (for medium, minimum and maximum meals).

• The currents in the Romanian seaside - are grouped in: coastal currents; currents

from the mouth of the Danube (there is a well-defined critical liquid flow above the value

of which the salty waters of the Black Sea do not penetrate into the riverbed); the currents

between the river mouths (on the Danube Delta, between the mouths of the arms and the

baths, the sea currents are conditioned by the wind regime).

For example, Fig. 4 shows the variation of the anode frequency of surface current

directions and speed steps at s.h. Constanta Comparator Casino in the years 2014, 2015,

2016. (s.h. - hydrometric station).

The Black Sea Waves in the Romanian seaside area - during the year, about 50%

winds with speeds of zero - 5 m/s, 34% at speeds of 5 - 10 m/s, 9% at speeds of 10-15 m/s

and about 3% storm winds. The frequency of storm winds (more than 15 m / s) is much

higher off the sea (4.2%) at Sulina and the Serpent Island). The very low frequency of calm

(2 - 4%) in the Sulina mouth is due only to breeze effects occurring between the sea and the


sea; the statistical analysis of the wave propagation directions shows that most of the waves

come from the sea, with predominance in the south-eastern sector.

Fig. 3 The variation and trends of the average, minimum and maximum annual levels

(period 1858-2016), (Hmed - average level,, Hmin-minimum level, Hmax - maximum

level, H - level) s.h. Sulina Semnal Ceata

Fig. 4 Yearly variation of surface currents and speeds directions, compared to 2014, 2015,

2016 at s.h. Constanta Casino

As an example, in Fig. 5 and Fig. 6, two histograms representing the annual wave

frequencies on height and period steps, at s.h. Mangalia, conquering for 2016 and 2017.

Fig. 5 Yearly wave frequencies by height steps at s.h. Mangalia, compared to 2016, 2017

0.00

10.00

20.00

30.00

40.00

50.00N

NE

E

SE

S

SV

V

NV

total (%)2014 total (%)2015 total (%)2016

Directions

The annual frequency of currents at speed intervals

0

10

20

30

40

50

60

70

0.0- 1.0 1.1- 3.0 3.1- 5.0 5.1-10.0 10.1-13.0 13.1-15.0 15.1-17.0 17.1-22.0 22.1-28.0 > 28.0

Speed intervals (cm/s)

Freq

uen

cy (

%)

TOTAL (%)2014 TOTAL (%) 2015 TOTAL (%) 2016

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

0.00-0.25 0.25-0.50 0.50-0.75 0.75-1.00 1.00-1.25 1.25-1.50 1.50-1.75 1.75-2.00 2.00-2.25 2.25-2.50 2.50-2.75 2.75-3.00 3.00-3.25 3.25-3.50 3.50-3.75 3.75-4.00 4.00-4.25 4.25-4.50 4.50-4.75 4.75-5.00 > 5.00

Height (m)

Fre

qu

en

cy

(%

)

total (%)2016 total (%)2017


Fig. 6 Annual waves frequencies per period steps at s.h. Mangalia, compared to 2016, 2017

• Water temperature. The Black Sea waters in the Black Sea coast are characterized

by an average annual temperature of 12.6°C near the shore and 13.0°C offshore. The

average annual air temperature at the coast is about 10.7 °C. The maximum sea water

temperature sometimes reaches 27°C (surface) in July. Vertically, there is an intense

thermal stratification with narrow variations. Highest temperature variations occur in spring

in the 10m layer and 10-30m in summer and autumn.

For example, Fig. 7 shows the variation in annual average water temperatures over a

period of 1857-2016 per cent. Sulina Port / Sulina Semnal Ceaţă.

Fig. 7 Variation and trend of annual average water temperature (1857-2016) -s.h. Sulina

Port / Sulina Semnal Ceaţă (T water - water temperature)

• Salinity of water. Characteristic of the Romanian seaside is that the vertical

distribution of salinity suffers variations of place and season. Average characteristics of the

vertical distribution of the Black Sea salinity at the Romanian seaside: in the water blanket

between the surface and the 10 m deep horizon the salinity has values lower than 15 ‰,

being very variable in space and time; isohalina of 17 ‰ is located in the water blanket

between the horizons of 10 and 25 m; Between the 25-meter horizon and the bottom of the

sea the salinity has values higher than 17 ‰, reaching up to 21 ‰ at depths of 100 m; at

depths of 180 m the salinity reaches the value of 22 ‰ and even more.

As an example, in figure 8 the salinity variation of the marine water in s.h. Eforie

Sud, in the period 1991 - 2017 (with interruptions); there is a tendency to increase salinity.

0

10

20

30

40

50

60

70

0.1-1 1.01--2 2.01--3 3.01--4 4.01--5 5.01--6 6.01--7 7.01--8 8.01--9 >9.01

Period (s)

Fre

qu

en

cy (

%)

TOTAL (%)2016 TOTAL (%)2017

0

2

4

6

8

10

12

14

16

1857

1859

1861

1863

1865

1867

1869

1871

1873

1875

1877

1879

1881

1883

1885

1887

1889

1891

1893

1895

1897

1899

1901

1903

1905

1907

1909

1911

1913

1915

1917

1919

1921

1923

1925

1927

1929

1931

1933

1935

1937

1939

1941

1943

1945

1947

1949

1951

1953

1955

1957

1959

1961

1963

1965

1967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

Ta

pa

(0 C

)

Tmed anuale apa Slp, Slsc 1857-2016 Poly. ( Tmed anuale apa Slp, Slsc 1857-2016 )


Fig. 8 Variation of salinity of marine water at m.ph. Eforie Sud

• Chemistry, radioactivity and general physical characteristics of water. In the

Romanian seaside area, due to the process of sweetening of marine waters under the

influence of river spills, the composition of the marine water ions varies sensitively

depending on the hydrological regime of the Danube. As is known, calcium bicarbonates

predominate in river waters, while marine waters predominate sodium chlorides.

Radioactivity of water, sediment or biota is variable. For example, after the Chernobyl

accident, aquatic organisms (molluscs and fish) harvested from the Danube Delta and the

Black Sea showed concentrations of Cs - 137 that exceeded 50 Bq / kg of dry sediment.

6. CONDITIONS FOR APPLYING THE COMPLEX FOR THE BLACK SEA

ROMANIAN COASTAL MODEL

The marine complex model is based on the coupling of two models: a marine physical

model - the Princeton Ocean Model (POM) and a marine ecological model ERSEM III.

In order to apply the complex model (ie the coupling of the POM and ERSEM III

models) to the Romanian Black Sea coastal area, more conditions have to be fulfilled, the

first condition being the adaptation to this area of the complex model. This was done by

realizing two models, namely BREG - the regional model for the entire Black Sea surface

and BSHELF - the zonal model for the Romanian coastal area; this is because, as has been

seen in the previous chapters, the coastal area suffers from the Black Sea influences,

considered as a whole aquatic object [5].

These models came directly from the Princeton Ocean Model (POM) and ERSEM III and

were written in the programming language (code) FORTRAN 77 and run in the LINUX

MANDRAKE 9 operating system. The adapted programs were made by R. Sorgente and

M.Zavatarelli, of ICM Sardinia (BREG, BSHELF) and M. Vichi, of INGV Bologna (ERSEM III).

12-month weather climatological data was provided by the ERA-European Center for

6-hourly Re-Analysis for the 6 hour weather forecast. This data set (1° x 1°) contains wind,

wind, wind, wind, wind, clouds, and wind velocity averages (averages from 1 January 1979

to 31 December 1993).

The physical parameters considered in the modeling are: the elevation (profile) - eta,

the temperature-tem, the salinity-sal, the radiated heat flux, the total heat flow qtot, the

wind stress in the x-wsu direction, (wind pressure) in the direction y - wsv, evaporation -

emp, pressure in the direction x - ubar, pressure in the direction y - vbar, velocity in

direction x - u, velocity in direction y - v, speed in direction z - w. Ecological parameters

considered: Elementary structures: C - carbon, N - nitrate, P - phosphate, O - oxygen, I -

solar radiation, M - depth (m), R - reduction equivalences; pelagic structures; benthic

structures; ecological transport variables.

0

5

10

15

20

25

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

2017

Sa

lin

ity

(‰

)

interruptions

interruptions interruptions

interruptions


Some peculiarities (conditions of application) of the complex model:

1. The programs run under LINUX MANDRAKE 9, the running time for each season

is about four hours, and the time increases even more with the higher the number of data.

2. Concerning boundary condition.

Very important for internal calculations are the definition of boundary boundary

conditions. At this stage, the marginal boundary conditions for the north, east, south

directions of the Romanian coastal zone are not strictly specified, this being one of the

conditions of applicability (Fig. 9).

Fig. 9 Delimitation of boundary conditions for the application of BREG / BHSELF to the

Romanian Black Sea coastal zone.

3. Another condition for the applicability of the complex model is the existence of a

continuous (continuous) implementation of monitoring data.

The data used was provided by the ERA (ERA) for 6 hours of Re-Analysis, being

implemented within a strictly separate program included in the BREG / BHSELF program

package. Using IM = 105, JM = 92 and KM = 24, then running the program in diagnostic mode

and visualizing with the grads program, the following graphical results are obtained, (example:

barotropic velocity at the sea surface (Fig. 10); salinity at a depth of 50 m (Fig. 11)).

Fig. 10 Barotropic velocity at sea surface

during the winter season

Fig. 11 Salinity distribution (psu) at a

depth of 50 m in the winter season


7. CONCLUSIONS

1. Existence of pollution risks, coastal erosion processes and socio-economic

activities call for integrated coastal zone management of the Black Sea. Integrated Coastal

Zone Management is an ensemble of several systems: the natural system, functional users

and the control system, which has the effect of achieving the conditions for sustainable

development in the area. Several strategies have been developed in this context, including

the legal strategy, law 280/2003, the W-BLESS feasibility program collaboration strategy,

as a result of Italian-Romanian collaboration.

2. One of the components of integrated coastal zone management is also the

monitoring system of the area and related to the development of some diagnostic and

prognostic models of defining parameters for marine physical and ecological processes that

are based on in-depth theoretical considerations. In this context, the following elements

should be considered: Marine physical environment (physical properties, marine water

dynamics, basic equations of fluid dynamics, ocean-ocean interface, ocean circulation,

fundamental marine parameters - density, temperature, salinity; elements of ocean and

ocean dynamics - waves, currents, fundamental ecological parameters - dissolved inorganic

matter, dissolved gases, dissolved organic matter, marine life groups and their dynamics.

3. Over time, various oceanographic institutions have developed different physical or

ecological models for the study of marine or oceanic processes. These models include the

Princeton Ocean Model (Physical Model) and ERSEM III (Ecological Model) model. By

adapting these models to the Romanian Black Sea coastline, the BREG / BSHELF models

were developed.

8. ACKNOWLEDGMENTS

Thanks Mrs. Prof. Dr. Carmen Maftei for support.

Thanks to Dr. Eng. Constantin Bondar and Dr. Eng. Batuca Dan Gheorghe for good

collaboration over time.

5. REFERENCES

1 ANTIPA GRIGORE - "Marea Neagră”, 1941 "Oceanografia, bionomia şi biologia

generală a Mării Negre", Academia Română, Publicaţiunile Fondului Vasile Adamachi,

vol. 1, TOMUL X, Nr. LV

2 BĂTUCĂ DAN, GH., (2003) "Caracterizarea corpurilor de ape costiere si tranzitorii

(Studii privind corelarea cu directiva cadru a uniunii europene privind resursele de apa) -

Tema B.9 – Faza 9.3

3 BONDAR, C., ROVENTA, V., STATE, I., (1973) "Marea Neagra in zona litiralului

romanesc – monografie hidrologica", Bucuresti

4 BONDAR, C., (1984) "Compoziţia chimică a apei Mării Negre în zona Agigea", Studiu

hidrologic, Bucureşti

5 BORCIA, C. (2004) "Aplicarea unui model complex marin in vederea diagnosticarii

parametrilor fizico-ecologici caracteristici zonei costiere a Marii Negre", tema 13,

M.M.G.A.


6 BORCIA, C., BLENDEA, V., GEORGESCU, I, I. (2001) "Aspecte privind

interdependentele dintre unii indicatori calitativi ai apei marine în zona de coastă a Mării

Negre", Sesiunea Comunnicari Stiintifice INMH. Bucuresti

7 BORCIA, C. (2016) "Aspecte privind istoricul observaţiilor şi măsurătorilor pe

Dunăre, Delta Dunării şi zona costieră a Mării Negre", manuscris

8 GEORGESCU, I., I., (1992-1996) "Determinarea indicatorilor radiochimiciai apei

nefiltrate si sedimentelor colectate de pe Dunare si litoralul romanesc al Marii Negre",

Bucuresti

9 PÄTSCH, J., (2001) "The Long Term Run the ecosystem model ERSEM: technical

guidance for PC application", Institute of Oceanography Hamburg, December 20

10 Studii hidrologice marine - DADL Constanţa, 1991 - 2017

11 Anuarul hidrologic al Mării Negre, 2014-2017

Black Sea - winter 2006

__________________

Note:

Constantin Borcia - National Institute of Hydrology and Water Management, Bucharest, Romania


DOI: 10.2478/ouacsce-2018-0004

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Validation of Building Energy Modeling Tools for a

Residential Building in Brasov Area-Romania

Lucian Cîrstolovean, Paraschiva Mizgan

_____________________________________________________________________

Abstract – A building energy model is a simulation tool which calculates the

thermal loads and energy use in buildings. Building energy models provide valuable

insight into energy use in buildings based on architecture, materials and thermal loads.

In addition, building energy models also must account for the effects of the building’s

occupants in terms of energy use. In this paper we discuss building energy models and

their accuracy in predicting energy use. In particular, we focus on two types of

validation methods which have been used to investigate the accuracy of building energy

models and on how they account for their effects on occupants. The analyzed building is

P + M located in the climatic zone 4, Sânpetru / Braşov. We have carried out a detailed

and exemplary energy needs analysis using two methods of analysis.

Keywords – building, energy model, thermal load, occupants

_____________________________________________________________________

1. INTRODUCTION

Buildings are a central element of EU energy efficiency policy, of the total energy

consumption, buildings account for about 40% of final energy consumption and 36% of

greenhouse gas emissions. Improving the energy efficiency of the European stock of

buildings is essential, not only to meet the EU 2020 targets, but also to meet the longer term

objectives of the climate change strategy.

A building energy model is a simulation tool which calculates the thermal loads and

energy use of buildings. The models are typically used in the design of new buildings and in

the renovation of existing buildings. The purpose is to predict energy use based on the

building’s architecture, heating system, ventilation and air conditioning systems [1]. Building

energy models are used by a variety of professions ranging from architects to engineers.

In addition to the occupancy survey, Knight et al. [1], [7] use the building energy

models ECOTECT, which calculate the heating and cooling loads, and BEM, which is a

coarser model for predicting yearly usage, to model the building. According to Knight et al.

[1], [7], neither model has been validated, but they claim that ECOTECT is ‘known to give

a reasonable estimate of heating loads in buildings’, and from that they conclude that other

programs such as Energy-Plus would provide the same results as ECOTECT [1],[7]. In our

country, Romania, buildings services engineers are those who are most interested to apply

these calculation models. The buildings services engineers are responsible for the buildings

services equipment and for comfort assurance.

Calculation models that have been validated are usually only considered for cases under

specific ranges of conditions, which exclude real life conditions such as the effects of building

occupants on energy usage [2]. The behavior of a building’s occupants can have a significant


impact on the energy use of a building. Building occupants will affect the building energy use

through the temperature set points, heating/cooling schedules of the building [2].

In this paper, we present an evaluation and a validation of building energy models

under idealized and realistic conditions. The evaluation considers calculation models that

discuss the validation and verification of building energy calculation models use in our

country (Romania), in our conditions, which are used to predict the energy use of a building

based on the heat transfer, thermodynamics, building architecture, and specific materials

and buildings services equipment of a building. We present a theoretical calculus of energy

consumptions for a residential building using a theoretical methodology by using a

computer programme. We also present a real value of energy consumption for our building

considering real measurement for gas and electricity. Articles that discuss methods for

including and validating occupant effects in building energy models were also considered.

2. MATERIALS AND METHODS

The building that we evaluated in terms of energy consumption is located in Brasov,

Romania:

Type: Family house (4 persons)

Year of building: 2010

Dimensions: width l = 10.10 m; length, L = 15.7 m; height, H = 8.7 m.

Levels:

- Ground floor: A = 146 m2; P = 15.45 m; h = 2.7 m

- Attic: A = 146 m2; P = 15.45 m; h = 2.6 m

External walls:

- interior plaster, 3 cm

- brick masonry, 30 cm

- polystyrene , 10 cm

Internal walls:

- interior plaster, 3 cm

- brick masonry 20 cm

- PVC joinery with double-glazed windows

Heat supply: 24 h, continuously.

Equipment from the boiler room:

- Gas boiler 24 kW Thermal agent, hot water 75/55ºC;

- Circulating pump

- Expansion tank

- Separation-isolation and safety fittings;

Heating system:

1. Heating units equipped with control valves, located below the windows;

2. The pipes of the internal heating system are made by polypropylene.

3. The distribution system of thermal agent is bi-tubular.

2.1 The calculus of energy consumption according to MC001 Romanian methodology [9]

The heat loss of the heated space is:

𝑄ℎ = 𝑄𝐿 − 𝜂 ∙ 𝑄𝑔 = 51771 − 0,94 ∙ 37275,93 = 16637,31⌈𝑘𝑊ℎ⌉ (1)

𝑄ℎ= heat loss of heated space of building, ⌈𝑘𝑊ℎ⌉


𝑄𝐿= transmission heat loss of the building, ⌈𝑘𝑊ℎ⌉

𝑄𝑔= the heat inputs of the building, ⌈𝑘𝑊ℎ⌉

𝜂= factor of reducing heat inputs

𝑄𝐿= 51771 [𝑘𝑊ℎ]; (2)

𝑄𝑔=37275, 95 [𝑘𝑊ℎ]; (3)

𝜂1 =1−𝛾𝑎

1−𝛾𝑎+1=0,9425 (4)

The total energy consumption of the buildings is:

𝑄𝑓ℎ = 𝑄ℎ + 𝑄𝑡ℎ − 𝑄𝑟ℎ,ℎ − 𝑄𝑟𝑤ℎ ⌈𝑘𝑊ℎ⌉ (5)

𝑄ℎ= heat loss of heated space of the building, ⌈𝑘𝑊ℎ⌉

𝑄𝑡ℎ= heat loss of heating system of the building, ⌈𝑘𝑊ℎ⌉

𝑄𝑟ℎ,ℎ= heat recovery from heating system of the building, ⌈𝑘𝑊ℎ⌉

𝑄𝑟𝑤ℎ=heat recovery from sanitary system of the building, ⌈𝑘𝑊ℎ⌉

𝑄𝑡ℎ = 𝑄𝑒𝑚 + 𝑄𝑑 , [𝑘𝑊ℎ

𝑎𝑛] (6)

𝑄𝑒𝑚 =Heat loss due to the heat emission system, ⌈𝑘𝑊ℎ⌉

𝑄𝑑 =Heat loss due to the heat distribution system, ⌈𝑘𝑊ℎ⌉

𝑄𝑒𝑚 = 𝑄𝑒𝑚,𝑠𝑡𝑟 + 𝑄𝑒𝑚,𝑐 (7)

𝑄𝑒𝑚,𝑠𝑡𝑟 =Heat loss due to the uneven uniform distribution of temperature,⌈𝑘𝑊ℎ⌉

𝑄𝑒𝑚,𝑐= Heat loss due to the internal temperature control devices, ⌈𝑘𝑊ℎ⌉

𝑄𝑒𝑚,𝑠𝑡𝑟 =1−𝜂𝑒𝑚

𝜂𝑒𝑚∙ 𝑄ℎ =

1−0,93

0,93∙ 16637,31 = 1252,27 𝑘𝑊ℎ (8)

𝜂𝑒𝑚 = The efficiency of the heat transmission system,

𝜂𝑒𝑚 = 0,93 𝑓𝑟𝑜𝑚 𝑀𝐶 𝐼𝐼 − 1 𝐴𝑛𝑒𝑥𝑎 𝐼𝐼 1𝐵

𝑄𝑒𝑚,𝑐 =1−𝜂𝑐

𝜂𝑐∙ 𝑄ℎ =

1−0,94

0,94∙ 16637,31 = 1061,95 ⌈𝑘𝑊ℎ⌉ (9)

𝜂𝑐 = The efficiency of the heat control system,

𝜂𝑐 = 0, 94 𝑟𝑜𝑚 𝑀𝐶 𝐼𝐼 − 1 𝐴𝑛𝑒𝑥𝑎 𝐼𝐼 1𝐵

𝑄𝑒𝑚 = 𝑄𝑒𝑚,𝑠𝑡𝑟 + 𝑄𝑒𝑚,𝑐 = 1252,27 + 1061,95 = 2314,22 ⌈𝑘𝑊ℎ⌉ (10)


𝑄𝑑 = ∑ 𝑈𝑖 ∙ (𝜃𝑚 − 𝜃𝑎𝑖) ∙ 𝐿𝑖 ∙ 𝑡𝐻 , ⌈𝑘𝑊ℎ⌉ (11)

𝑄𝑑= heat loss on distribution system of heating system, ⌈𝑘𝑊ℎ⌉

𝑄𝑑 =6237,428 ⌈𝑘𝑊ℎ⌉ (12)

Qth = 2314,22 + 6237,428 = 8550,2 kWh (13)

The energy consumption of building according to MC001 methodology is:

Qfh = 8550,2 + 16637,3 = 25187,5 kWh (14)

2.2. Analyzing real energy consumption based on 3-month utility consumption and

comparing with the resulting MC001 calculations

Speaking about realistic validation studies, theoretical building energy models are

compared to metering data from real buildings. In our realistic validation, authors have tried

to validate the physics behind the models; occupants’ behavior is typically included in

building energy modeling by setting the heating, equipment and temperature set points

based on the hours of use by the occupants and local weather conditions. The theoretical

models used are often designed on the assumption that occupants will use the building in

the way it is designed. According to the real data gathered from the field regarding the real

consumption of the analyzed building, Table 1 presents the real energy consumption for:

November, December and January 2017-2018.

Table 1. Energy consumption for November, December and January 2017-2018

Heat Consumption

kWh

Power consumption

kWh

Total

kWh

November 11678 704 12382

December 12651 1048 13699

January 12975 845 13820

Average outside temperatures for November, December and January 2017-2018 are

shown in Table 2.

Table 2. Average outside temperatures for November, December and January 2017- 2018

November December January

day 7 2 0

night -4 -8 -9

average 2 -3 -5


Fig. 1 Energy consumption graph for: November, December, January 2017-2018

Fig. 2 Comparative chart of energy consumption for November, December and January

with theoretical energy consumption calculated according to the MC001 methodology

2.3. RETScreen method to compare the predictions of building energy models[10]

The RETScreen program has calculated the energy requirement for heating, but also

the electricity needed for the building under consideration [10].

Tabel 3. The result of calculating the energy consumption for the building analyzed with

the RETScreen program


Tabel 4. Results obtained with RETScreen programme

Heat Electricity Total

Energy demand (MWh) (MWh) (MWh)

Energy demand 18.3 10.4 28.7

2.4. Comparing the obtained results: MC001, real consumption and RETScreen

programme

Fig 4 Comparison the results (Real consumption, MC001, RETSCREEN)

2.5. Building energy modeling and occupancy behavior

Several studies have been done on the effects of occupant behavior on building

energy modeling [1], [2], [3], [4] and on advanced methods of including occupancy

behavior in building energy models [2], [5].

Occupant behavior can be defined as ‘the presence of people in the building’ and also

‘the actions users take (or not) to influence the indoor environment’ [1], [2].

In most building energy models occupant behavior is modeled in a very simple form

with set schedules for occupancy.

Using more complex models based on surveys and stochastic models can refine the

inputs for occupant behavior and improve the accuracy of the building energy model [1],

[2], [5].

Stochastic models use a set of rules to determine the probability that an event will

happen. Tanimoto et al. [8] divide users into sub-categories based on age and lifestyle and

use a Monte Carlo analysis to determine what activities each group is doing throughout the

day and how that affects the energy use of a multi-family residence.

Clevenger and Haymaker [1], [6] investigated what effect different occupancy

controlled parameters have on the predicted energy use of a school building.

They looked at the effects of eleven different building modeling parameters on the

energy use of a school building.

Using a survey of building operators, they determined the range of setting used for

each of the eleven parameters.

Simulations were run to study the sensitivity of the building energy model to each of

the parameters.

They found that different occupancy controlled parameters can change the energy use

of a school building by up to 40%.


3. CONCLUSIONS

Building energy modeling tools provide a simple method for predicting the energy

use of new and existing buildings. More and more the society demands for new energy

efficient construction and retrofits, thus, predicting energy use is essential to the design

process of buildings and for all facilities.

Generally speaking, all models are able to predict energy use for different building

and heating systems designs without any need for experimentation. As new calculus models

are developed and existing building energy models are improved, the validation

methodologies for building energy models also need to improve and expand to assess their

validity.

All studies which have considered the effects of occupants on building energy models

have shown that building energy models are very sensitive to occupants’ behaviors. In all

study cases, building energy models do not accurately represent the occupants’ behaviors.

To improve the accuracy of building energy models it is necessary to consider the

behaviors of occupants in all simulation cases, in particular for each building. In this way

the accuracy of simulation is certified and the real energy consumption is determined.

Analyzing the consumption and energy requirements for the P + M building, located

in the IV climate zone, Zaharia Bârsan Street, no. 13, Braşov County, we can say that the

energy demand resulting from the calculations according to the MC001 methodology is

12% less than the RETScreen program, but in both cases it is considerably higher than the

actual consumption of the building, following the analysis for November, December and

January 2017-2018.

We consider that occupants’ behaviors are those making the differences in energy

consumptions of the analyzed building.

5. REFERENCES

[1] Emily M. Ryan, Thomas F. Sanquist, (2012), Validation of building energy modeling

tools under idealized and realistic conditions. Energy and Buildings 47, pp 375–382

[2] P. Hoes, et al. (2009), User behavior in whole building simulation, Energy and

Buildings 41, pp. 295–302

[3] C.M. Clevenger, J. Haymaker, (2006), The impact of the building occupant on energy

modeling simulations, in: Computing and Decision Making in Civil and Building

Engineering, International Society for Computing in Civil and Building Engineering,

Montreal, Canada

[4] S.C. Gaceo, F.I. Vazquez, V. Moreno, (2009), Comparison of standard and case-based

user profiles in building’s energy performance simulation, in: Building Simulation,

International Building Performance Simulation Association, Glasgow, Scotland, pp. 584–

590

[5] J. Tanimoto, A. Hagishima, H. Sagara, (2008), A methodology for peak energy

requirement considering actual variation of occupants’ behavior schedules, Building and

Environment 43, pp. 610–619

[6] C.M. Clevenger, J. Haymaker, (2006), The impact of the building occupant on energy

modeling simulations, in: Computing and Decision Making in Civil and Building

Engineering, International Society for Computing in Civil and Building Engineering,

Montreal, Canada


[7] I. Knight, S. Stravoravdis, S. Lasvaux, (2007), Assessing the operational energy profiles

of UK education buildings: findings from detailed surveys and modelling compared to

measured consumption, in: 2nd PALENC Conference and 28th AIVC Conference on

Building Low Energy Cooling and Advanced Ventilation Technologies in the 21st Century,

Crete Island, Greece, pp. 531–536

[8] J. Tanimoto, A. Hagishima, H. Sagara, (2008), A methodology for peak energy

requirement considering actual variation of occupants’ behavior schedules, Building and

Environment 43, pp. 610–619

[9] MC001 Methodology for calculation of energy performance of building

[10] RETScreen programme. https://www.nrcan.gc.ca/energy/software-tools/7465

________________

Note:

Lucian Cirstolovean – Transilvania University Brasov, Department Buildings Services, Romania

(corresponding author to provide phone: +40722294552; e-mail: [email protected]). Paraschiva Mizgan - Transilvania University Brasov, Department Civil Engineering, Romania, (e-mail:

[email protected]).


DOI: 10.2478/ouacsce-2018-0005

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Analysis on Variability of Buzau River Monthly

Discharges

Cristina Amalia Mocanu -Vargancsik, Alina Barbulescu

_____________________________________________________________________

Abstract – The purpose of this article is analysing the variability of Buzau river

monthly mean discharges, maximum and minimum over time and the impact of Siriu

Dam on these discharges. Keeping a stable, moderate variability on the water flow has

a significant importance, as this assures normality of life and functionality of the

dams. On another hand, the dams are in-built with a range of parameters, decided

according to this variability of the discharges. The used data has been collected from

Nehoiu and Basca Roziliei hydrometric stations and spans on 55 years, from 1st

January 1955 to 31st December 2010. Mid-period, on 30th September 1984, Siriu Dam

started operating and the results reveal that its impact on the variability has been

moderate on a large time scale. Important changes appear on smaller time scale, as

months. The results are supported by graphs drawn in Excel and methods embedded

by software.

Keywords – Buzau River, monthly maxim, monthly minim, monthly mean

discharges, standard deviation, Siriu Dam

_____________________________________________________________________

1. INTRODUCTION

The changes of a river flow can be seen only doing an analysis over a long period of

time. In this way, can be noticed the impact of the climate changes, hydrological

constructions, the human activities, and the appropriate use of the river resources. All lead

towards a conclusion affecting the environment and help to take necessary steps for

protection, preservation, and good exploitation. The main purpose of the dam construction

is the reduction of flow therefore of stream power in order to control flood, to generate

power, irrigation, sediment control, industrial and domestic supply. Usually, peaks are

reduced. (Higgs and Petts, 1988, apud [1]).

The topic for the monthly mean discharges of Buzau River has been treated in some

other papers Chendes (2011), Minea (2011), Minea and Barbulescu, (2014), Barbulescu

(2017). In the last two mentioned papers, the same period of time has been divided in

before and after the construction of Siriu Dam. To these existing studies, this article adds

the variability of monthly extreme values, before and after Siriu Dam construction. Because

its late inauguration in 1984 (30th September), the data has been divided in 1955-1984 and

1985-2010.

In Romania, high water levels are characteristic to spring due snow-melting and rains

and in autumn due frontal rains. Although may occur any time, floods are most likely in

spring and summer, when up to 40%-50% of overall annual floods occur in Romania (***,


1971). They are short-lived (from few hours to few days), but have spectacular peaks. This

is the good reason of seasonal observations of water peaks.

2. EXPERIMENT DESCRIPTION

Our focus is on Buzau River with the drainage area of 5264 km2, lying in a

temperate-continental climate, in the Carpathians’ Curvature. The study area is shown on

Figure 1.

The last 50 years, the mean annual air temperature was about 6°C and the minimum

one was about 1°C. In the period 1950-2010, the mean multi-annual average precipitation

was between 500 mm and 1000 mm and the maximum precipitation of 130 mm [4],

recorded in the period June – July. The local winds that influence the climate are Crivat – a

north-easterly during the winter time – and Austru – a south-easterly with dry air during the

summer time that warms the winter days [10].

Fig. 1 The upper part of the Buzău River Catchment (Minea and Chendes, 2013)

The series were collected at Nehoiu and Basca Roziliei hydrometric stations (hs).

Nehoiu is situated at the latitude of 45°25’29”, the longitude of 26°18’27". This station has

the following morphometric and hydrological characteristics: river length from the source

of 71.5 km, the average slope of the river from the source of 0.73°, the areal area of 1567

km2, the average elevation of the areal at the station of 1043 m, the multi-annual mean of

the flow of 21.9 m3/s, the specific mean of 17 l/s.km

2. At Nehoiu station, Buzau river drains


a surface of 1,567 km2 [8]. Bâsca Roziliei hs is situated on Bâsca River - tributary to Buzau

River. Bâsca River flows into Buzau River at a point upstream Nehoiu station, such that

Nehoiu hs records the joint flows from Buzau River downstream Siriu Dam and Bâsca

River (see Figure 1). Bâsca Roziliei hs is at the latitude of 45°26’32”, the longitude of

26°16’38" and it has the following morphometric and hydrological characteristics: the river

length from the source to the hydrometric station is 17.1 km, the average slope of the river

from the source to the hydrometric station of 1.66°, the basin area associated to the

hydrometric station of 107 km2, the average elevation of the basin at the hydrometric

station – 1275 m, the average multi-annual fluid flow 2.3 m3/s; the specific mean 21.5

l/s.km2 [8].

The hydrological working data have been provided by the National Institute of

Hydrology and Water Management Bucharest, Romania and consist in daily mean flow

discharges during 01.01.1955 and 31.12.2010. This series has been divided in 01.01.1955-

31.12.1984 and 01.01.1985-31.12.2010, corresponding to pre- and post- Siriu Dam

construction. The minim of 20 year continuous data measurement is satisfied, as per

methodological requirements of hydrological series.

Let us define the deviation of a data as the difference between the actual value and the

mean value of the data set.

Monthly deviations of the mean, minim and maxim for Nehoiu hs have been

computed. Standard deviations of monthly means, maxim and minim have also been

calculated. Computations have been provided for Basca Roziliei hs only for those particular

months that have “abnormal” behaviour from the general trend.

3. RESULTS AND SIGNIFICANCES

For Nehoiu hs, the output for each monthly deviations of the mean, minim and maxim

have been represented on the same graphs, using different colours: blue for the mean, green

for the minim and red for the maxim (Fig. 2 and Fig. 3). On each graph, the red dotted

vertical line separates the time line (x-axis) in pre- and post- Siriu Dam construction.

The mean and minim show a small and moderate variability, depending on the season.

With no exception and as expected, for all the months, the maxim shows the biggest

variation. After 1984, all monthly parameters are diminished in value and their peaks are

diminished in number and value. They vary from a month to another due of the pluvial or

nival regime.

On a large scale, the influence of the Siriu Dam is obvious.

In order to support the importance of the Siriu Dam, the monthly standard deviation

of the mean, minim and maxim before and after the construction of the Siriu Dam and their

percentages of changes have been calculated. The results are summarized in Table 1.

To bring more significance, the decreasing percentages are green and the increasing

ones are red.

The large majority of the results confirm our statement with significant numbers.

March and April – months with seasonal rains – support our statement, as well October,

November, December and January. The only two high percentages of increase occur for

June in mean and maxim. Smaller increases are noticed in February for the mean and the

minim, in May for the minim, and in August for the mean and the minim.


Fig. 2 January to June monthly deviations for mean, minim, maxim

Table 1. Monthly Standard Deviations and Percentages of Changes at Nehoiu

Month

Std. Dev. Before

1984

Std. Dev. After

1984

Percentages of

Changes (%)

Mean Min Max Mean Min Max Mean Min Max

January 7.62 3.19 31.41 5.82 2.09 17.76 -23.68 -34.47 -43.46

February 7.23 2.79 31.43 7.43 3.08 17.14 2.77 10.15 -45.47

March 15.48 3.90 67.40 10.77 2.94 49.71 -30.44 -24.65 -26.25

April 22.91 12.25 51.94 19.34 8.49 34.93 -15.61 -30.73 -32.75

May 21.07 6.99 138.54 18.21 7.42 50.63 -13.54 6.14 -63.45

June 12.21 4.56 72.51 19.30 3.21 140.89 58.12 -29.60 94.30

July 20.97 4.25 169.48 14.18 4.11 46.49 -32.40 -3.17 -72.57

August 11.99 3.88 70.23 12.49 4.04 37.41 4.15 4.14 -46.73

September 11.59 3.51 94.43 9.67 2.03 42.92 -16.59 -42.24 -54.55

October 14.20 5.78 57.59 7.83 2.81 26.79 -44.85 -51.37 -53.49

November 9.16 4.79 62.77 6.84 2.28 29.97 -25.38 -52.35 -52.25

December 9.15 3.88 62.35 7.74 2.33 23.77 -15.41 -39.95 -61.87


Fig. 3 July to December monthly deviations for mean, minim, maxim

For these months, the same parameters have been analysed at Basca Roziliei hs. The

results are summarized in Table 2. We remark t he same type of changes (increase or

decrease) for the same parameters. Moreover, the percentages of increase are much larger

than those at Nehoiu hs. These confirm our theory that Siriu Dam attenuates the water

flows. June still remains a problematic month. June is the main seasonal flow exhibited by

most rivers is the Subcarpathian pluvial regime, in which rains fall, often accompanied by

floods, generates high flows.

Table 2. Monthly Standard Deviations and Percentages of Changes at Basca Roziliei

Month Std. Dev. Before 1984 Std. Dev. After 1984

Percentages of

Changes (%)

Mean Min Max Mean Min Max Mean Min Max

February 2.88 0.98 15.97 3.13 1.44 9.73 8.79 46.59 -39.03

May 12.61 3.88 77.01 12.46 3.99 43.85 -1.19 2.82 -43.06

June 6.56 2.40 45.07 12.53 2.41 100.00 90.92 0.29 121.88

August 6.54 1.74 38.57 6.89 2.29 34.95 5.39 31.54 -9.37


4. CONCLUSION

The dam construction comes with a lot of benefits for flow regulation, flood

prevention and area safety. After the studied period, in 2013, in July 2013, the left bank of

Basca River required immediate action of soil strengthening because of landslide [9].

Usually seasonal rains cause this problem. As far as known, a small dam has been built on

Basca River in order to prevent floods and landslides.

5. REFERENCES

1 Anders Brant, S. (2000), Classification of geomorphological effects downstream of

dams, Catena, vol. 40, issue 4, https://doi.org/10.1016/S0341-8162(00)00093-X.

[2] Bărbulescu, A. (2016) Studies on Time Series Applications in Environmental Sciences,

Intelligent Systems Reference Library 103, Springer Nature.

[3] Barbulescu, A. (2017), Statistical Assessment and Model for a River Flow under

Variable Conditions, Conference Paper. Retrieved from https://cest.gnest.org/sites/default/

files/presentation_file_list/cest2017_00715_poster_paper.pdf at 21st October 2018.

[4] Chendeş, V. (2011), Water resources in Curvature Subcarpathians. Geospatial

assessments, Editura Academiei Române, Bucureşti. (In Romanian with English abstract).

[5] Minea, S.I. (2011), The rivers from Buzău River Catchment. Hydrographical and

hydrological constructions, Editura Alpha MDN, Buzău (In Romanian).

[6] Minea G., Barbulescu A. (2014), Statistical Assessing of Hydrological Alteration of

Buzau River Induced by Siriu Dam, Forum Geografic. Studii si cercetari de geografie si

protectia mediului, Issue 1, vol. XIII, pag. 50-58, http://dx.doi.org/10.5775/fg2067-

4635.2014.104.i

[7] Minea, G., Chesdes, V. (2013), Some aspects regarding the maximum flow during the

cold season in the upper part of the Buzău River Catchment, Conference Paper. Retrieved

from https://www.researchgate.net/publicatio n/273243103_Some_aspects_regarding_the_

maximum_flow_during_the_cold_season_in_the_upper_part_of_the_Buzau_River_Catch

ment [20th

October 2018].

[8] National Institute of Hydrology and Water Management Bucharest (2013).

Hydrological data.

[9] * (2013) Raport Activitate ABA Buzau Ialomita. Retrieved from internet on 27th

Octomber 2018, p.7.

[10] ** Județele României Socialiste, p. 161. Retrieved from https://www.scribd.com/doc/

154175542/Judetele-Romaniei-Socialiste, 20th

October 2018.

[11] ***(2012) National Institute of Hydrology and Water Management, Bucharest.

________________

Note:

Mocanu -Vargancsik Cristina Amalia – Doctoral School, Technical University of Civil Engineering

Bucharest, Bd. Tei, 122-124, Bucharest, Romania (corresponding author to provide phone: +40-740-

077375; e-mail: [email protected]). Barbulescu Alina - Doctoral School, Technical University of Civil Engineering Bucharest, Bd. Tei, 122-

124, Bucharest, Romania (e-mail: [email protected]).

https://doi.org/10.1016/S0341-8162(00)00093-X

https://cest.gnest.org/sites/default/%20files/presentation_file_list/cest2017_00715_poster_paper.pdf%20at%2021st%20October%202018

https://cest.gnest.org/sites/default/%20files/presentation_file_list/cest2017_00715_poster_paper.pdf%20at%2021st%20October%202018

http://dx.doi.org/10.5775/fg2067-4635.2014.104.i

http://dx.doi.org/10.5775/fg2067-4635.2014.104.i

https://www.researchgate.net/publicatio%20n/273243103_Some_aspects_regarding_the_%20maximum_flow_during_the_cold_season_in_the_upper_part_of_the_Buzau_River_Catchment



https://www.scribd.com/doc/%20154175542/Judetele-Romaniei-Socialiste

https://www.scribd.com/doc/%20154175542/Judetele-Romaniei-Socialiste




DOI: 10.2478/ouacsce-2018-0006

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Studies Related to the Biological Treatment of

Wastewater within the Wastewater Treatment Plant

of Iași City

Costel-Cătălin Prăjanu, Daniel Toma, Cristina-Mihaela Vîrlan and Nicolae Marcoie

_____________________________________________________________________

Abstract – This paper includes an analysis of the biological treatment process existing

within the water supply and sewerage of Iași City. The main objective of biological

treatment is the removal of solid organic substances from wastewater, the stabilization

of sludge, the reduction of nutrients loads etc. The Iași City Wastewater Treatment

Plant was developed in several stages since year 1968. Nowadays, the facility operates

at a design flow rate of 4 m3/s during dry weather and 8 m

3/s during heavy rainfalls.

This study is focused on the following aspects: wastewater treatment plant’s diagram,

the wastewater parameters inside the treatment plant, the biological treatment

process analysis and a few conclusions.

Keywords – wastewater, wastewater treatment, sludge, biological treatment

_____________________________________________________________________

1. INTRODUCTION

Wastewater is water used in various sectors (domestic, social, industry etc.) and that

cannot be reused because it represents a hazard for environment. Therefore, due to its loads

in polluting compounds, acquired after use, this water must be purified before being

discharged into a natural emissary (be it river, lake, sea etc.).

The collected wastewater from Iași City area is conveyed by the sewerage network

towards the wastewater treatment plant through a final main collector having a length of

1320 m and a section of 2250/2500 x 3.

The hydraulic capacity and the polluting load of wastewater collected by the sewerage

network, which is conveyed towards Iași Wastewater Treatment Plant, is as it follows:

- Qus. av. day = 2,2 m3/s;

- Qus. max. day = 2,985 m3/s;

- BOD5 = 56,000 kg/day (293 mg/l);

- COD = 102,567 kg/day (537 mg/l);

- TSS = 65,33 kg/day (341 mg/l);

- TKN-N = 8,400 kg/day (45,9 mg/l);

- TP-P = 1,680 kg/day (8,8 mg/l);

- Qh max. (dry weather) = 10,630 m3/h;

- Qh max. (wet weather) = 29,640 m3/h;

- water temperature during a year ranges between 12°C and 26°C.


The Iași Wastewater Treatment Plant in Iași was developed in stages since 1968,

reaching now a design flow rate of 4 m3/s on dry weather and 8 m

3/s on heavy rainfall time.

Along the development of wastewater treatment plants, the workflow was hierarchally

designed and the plants became separated into sewerage treatment stage in order to better

control the process.

The treatment stages are:

- mechanical stage, that includes of pumping stations, fine and coarse screens, fat

separator, sand remover, primary clarifier etc. and where the suspensions and a small part

of organic load are retained;

- biological stage, that includes biological reactors, secondary sedimentation etc. and

where carbon-based biodegradable compounds are retained;

- the advanced treatment stage includes bioreactors, secondary sedimentation etc, and

it’s the stage where nutrients (nitrogen and phosphorus compounds) are neutralized in

biochemical processes in order to protect the emissary against eutrophication;

- the tertiary treatment stage, where the water quality can be improved for immediate

use.

At the same time, due to the complexity of wastewater treatment plants, it is common

to say that the plants include two main treatment lines:

- the water line;

- the sludge line.

2. DIAGRAM OF THE WASTEWATER TREATMENT PLANT

The wastewater treatment plant full process flow is shown in Figure 1:

Fig. 1 Wastewater treatment plant process diagram

As shown in diagram above (Fig. 1), the sewerage treatment process takes place as follows.

TOWARDSRIVER

TOWARDS FINALOUTLET

INTAKE, PUMPINGSTATION ANDDISCHARGE TO RIVER

PRE-TREATMENTLINE II AND PS

PRIMARYSEDIMENTATION

PRE-TREATMENTLINE I ANDPUMPING STATION

RAINWATER

TREATMENT

FINALSEDIMENTATION

BIOLOGICALTREATMENT

SLUDGE LICHIORSTORAGE TANK

BIOLOGICALSLUDGEMECHANICALTHICKENING

PRIMARY SLUDGEGRAVITY

THICKENING

SECONDARYANAEROBICDIGESTION

PRIMARYANAEROBIC

DIGESTION

SLUDGE STORAGETANKS DEWATERING

OF DIGESTEDSLUDGE

TOWARDS

RIVER


Wastewater from Iași City and neighboring localities, conveyed by gravity and by

pumps, reaches the intake chamber provided with a pumping station and a discharge system

towards the river. From here, the wastewater conveyed by gravity, reaches the pre-treatment

stage and the pumping station (Line 1 treats rainwater, while Line 2 treats the wastewater).

After pretreatment and pumping, the wastewater gets into the primary clarifiers, then,

gravitationally; the wastewater continues its route towards the biological stage, then to the

final clarifier.

Once the water travelled through this circuit, the treated water will comply with

directives and laws in force and is to be discharged into the emissary (i.e. Bahlui River).

In the plant, the processing of wastewater within all treatment stages generates sludge,

a harmful product for the environment. Because it damages the environment, the sludge

produced will also be treated before it is to be rendered to the nature circuit.

After treatment of rainwater, the treated water is gravitationally sent into emissary and

some of the sludge is pumped to the intake of the primary clarifier, the remainder being sent

to the gravitational thickening system for primary sludge (also by pumping).

The sludge from the primary sedimentation process is pumped towards the gravity

thickening system for primary sludge, then pumped towards the primary and secondary

anaerobic digestion tanks, and from here towards the sludge storage tanks, the digested

sludge dewatering facility and then towards final disposal.

The resulting sludge after final sedimentation is also pumped to the sludge mechanical

thickening system (excess sludge) and to biological treatment (return sludge).

The biological sludge from the mechanical thickening process reaches the primary

anaerobic digesters, intersecting the sludge from the primary sedimentation and continuing

its route towards final elimination.

The supernatant (sludge liquor) from mechanical and gravity thickening processes,

sludge storage tank and dehydration process of digested sludge will reach the sludge liquor

storage tank, and from there it will be reintroduced into the wastewater circuit in the

wastewater treatment plant before the intake of the primary sedimentation stage.

3. WASTEWATER CHARACTERISTICS

Wastewater, as well as drinking water supplied to population, industry etc., features

various physical, chemical, bacteriological and biological characteristics, that vary from

locality to locality and provide data on its quality.

The characteristics of wastewater in the Iași wastewater treatment plant are presented

in Table 1:

Table. 1. Wastewater characteristics within Wastewater Treatment Plant.

1 2 3 4 5 6 7 8 9 10

m3/d 191.3 197.0 195.2 191.1 4.11 1.59 253 4.29 1.35 5.63

COD (kg/d) 102.7 104.9 67.14 23.89 513 306 253 820 1.35 2.17

BOD (kg/d) 56.06 57.05 36.51 4.78 103 118 126 317 673 991

TKN (kg/d) 8.40 8.59 7.73 382 8 21 76 57 135 192

NO3 (kg/d) 0 24 24 1.53 33 9 0 24 0 24

TP (kg/d) 1.68 1.81 1.6 191 4 5 1,61 14 108 121

STM (kg/d) 65.25 69.5 25.02 6.69 35.5 79.9 50,5 1.59 2.66 4.26

The wastewater characteristics shown in Table 1 can indicate the plant’s efficiency.


The wastewater treatment plants efficiency is:

- COD – 76,7 %;

- BOD5 – 91,5 %;

- TSS – 89,7 %;

- TKN – 77,2 %;

- TP – 88,6 %.

The primary sedimentation efficiency is:

- BOD5 – 36 %;

- TSS – 64 %;

- TKN – 10 %;

- TP – 11 %.

The efficiency or the treatment rate is an indicator for the proper functioning of the

plant’s technological process.

4. ANALYSIS OF THE BIOLOGICAL TREATMENT PROCESS

The biological treatment of wastewater aims to rectify the wastewater’s quality by

means of microorganisms activity. The main goal of a biological treatment is the removal

of solid organic compounds from wastewater, the stabilization of sludge, the decreasing of

nutrient loads etc.

In the Iași wastewater treatment plant, the biological treatment of wastewater is

carried out by an artificial method, this being the active sludge bioreactor treatment, with

A2/O process (two anaerobic zones and one oxic zone).

Active sludge bioreactors are constructed, according to the A2/O scheme, as a device

including 3 zones: the anaerobic zone, the anoxic zone and the aerobic zone (oxic zone).

Biochemically controlled oxidation-reduction processes take place in these zones, this

leading to the decomposition of organic matter down into CO2, H2O and biomass, through

catabolic and anabolic processes, hydrolysis, nitrification, denitrification etc.

The capacity of the biological step is 92,480 m3 for bioreactors.

This bioreactors volume was divided into three zones and arranged on three

technological lines:

- Line 1 – 38 %, with a capacity of 35,280 m3, 7,9 % anaerobic volume, 22 % anoxic

volume and 70,1 % aerobic volume;

- Line 2 – 13,3 %, with a capacity of 12,300 m3, 7,9 % anaerobic volume, 22 %

anoxic volume and 70,1 % aerobic volume;

- Line 3 – 48,7 %, with a capacity of 44,900 m3, 7,9 % anaerobic volume, 22 %

anoxic volume and 70,1 % aerobic volume.

The biological processing capacity refers to the following parameters:

- BOD5 – 36,513 kg/d;

- COD – 67,144 kg/d;

- TKN – 7,733 kg/d;

- TP – 1,605 kg/d;

- TSS – 2,502 kg/d.


The main process parameters are the following:

- active sludge age – 8,7 days;

- SRTaerob – 6,62 days;

- active sludge production – 0,972 kg SS/kg BOD/day;

- excess sludge – 35,830 kg SS/day;

- SVI – 110 cm3/g;

- active sludge concentration MLVSS 3,701 mg/l;

- Vd/Vat – 0,239;

- active sludge aeration tanks – 311,600 kg SS;

- HRTanaerobic – 0,7 h;

- QIR – 250 %;

- QER – 75 %;

- MLSS – 4,1 g/m3;

- oxygenation capacity COpeak – 5,659 kg O2/h, with a peak factor (1,47) calculated

in order to ensure a concentration of 2 mg/l solved O2 for H – 3,45 m and Twater – 26 °C.

The plant, in the biological treatment zone, features three Phoredox type phrases, as it

is shown in the diagram in Fig. 2:

Fig. 2 The biological zone – process diagram

The nitrogen and phosphorus balance

The nitrogen incorporated in biomass cand be assessed as it follows:

%5SAS CBON (1)

SASoutinN NTKNTKNN (2)

outND 3NONN (3)

where:

- BOD - the amount of biodegradable matter (187 mg/l);

- inTKN - influent nitrogen (39,6 mg/l);


- outTKN - effluent nitrogen (2 mg/l);

- SASN - nitrogen in sludge (9,4 mg/l);

- NN - nitrogen in nitrification zone (28,2 mg/l);

- DN - nitrogen in de-nitrification zone (22,2 mg/l);

- out3NO - nitrate effluent (6 mg/l).

The phosphorus balance is estimated as it follows:

CBOP %5,1BioP (4)

CBOP %1SAS (5)

SASoutinchem PPPP (6)

where:

- BioPP - phosphorus incorporated in sludge, via BioP technique (2,8 mg/l);

- SASP - phosphorus incorporated in sludge, via normal absorbtion (1,9 mg/l);

- inP - phosphorus affluent (8,2 mg/l);

- outP - phosphorus effluent (1 mg/l);

- chemP - phosphorus removed via chemical reaction (2,5 mg/l).

Calculation of sludge age

All biological reactions are influenced by temperature, especially nitrification and the

reduction of nitrate to nitrogen. This factor affects the choice of sludge age and the lower is

the temperature during biological process, the higher is the sludge age.

The age of aerobic sludge is estimated as:

min15103,14,345,1aero

TSRT

(7)

VatVSRTSRT

/d1

1aerodim

(8)

The adopted values are:

- aeroSRT = 6,62 days (aerobic sludge age at minimum temperature);

- dimSRT = 8,7 days (total sludge age).


Production of biological sludge

The specific sludge production and the total production (digesters losses not included)

are:

- SPdc-BOD related sludge production (30,720 kgSS/day);

- SPBioP - extra sludge production, BioP process (1,658 kgSS/day);

- SPchem - chemical treatment sludge production (3,450 kgSS/day);

- SPtot - total sludge production (approx. 35,830 kgSS/zi).

Biological tanks volumes

The total value of necessary sludge XT and reactors total volumes Vat shall be:

dimtotT SRTSPX (9)

MLSS

X

VT

at (10)

where:

- sludge amount – approx. 311,600 kgSS;

- MLSS concentration – 3,701 mg/l;

- total volume – 84,193 m3;

- Vd/Vat ratio – 0,239;

- denitrification volume – approx. 20,150 m3;

- nitrification volume – approx. 64,030 m3.

The anaerobic reactor volume will be:

anaeroban )1( HRTRASQV (11)

where:

- flow on reactor’s inlet (affluent+RAS) - 14,362 m3/h;

- RAS coefficient – 75%;

- HRT inside reactor – 0,5 h;

- anaerobic volume – 7,181 m3;

- sludge fraction in anaerobic condition - approx. 7,9%.

5. CONCLUSIONS

As we have studied a topic on wastewater, we consider necessary and useful to give

some conclusions.

Following the analyzes carried out on the biological treatment of wastewater in the

wastewater treatment plant, we found the following:

- the decreasing of concentrations and quantities of polluting substances within the

limits of directives and laws in force;

- decreasing of eutrophicants in the wastewater treatment plant’s effluent;


- decreasing the amount of sludge resulting from technological processes;

- ensuring the compliance of concentrations and quantities of polluting substances

within the limits of the directives and laws in force;

- the wastewater treatment plant produced sludge: possibility of its reintroduction into

the natural circuit and its recovery, after a proper treatment;

- decreasing power consumption;

- power production;

- the efficiency or purification degree provided by technological process;

- protecting the environment and caring for the population.

6. REFERENCES

1 www.apavital.ro

[2] V. Rojanschi, T. Ognean (1989), Cartea operatorului din stații de tratare și epurare a

apelor uzate, Editura Tehnică București

[3] S. Perju, A. Mănescu (2011), Exploatarea sistemelor de alimentare cu apă și

canalizare, Editura Tehnică București

[4] ***Reabilitarea și Modernizarea Stației de Epurare Iași, proiect tehnic, 2012

________________

Note:

Prăjanu Costel-Cătălin – ”Gheorghe Asachi” University of Iași, Bd. D. Mangeron nr. 63, 900356-Iași, Romania (corresponding author to provide phone: +40-744-727530; e-mail: [email protected]).

Toma Daniel – ”Gheorghe Asachi” University of Iași, Bd. D. Mangeron nr. 63, 900356-Iași, Romania

(corresponding author to provide phone: +40-721-811373; e-mail: [email protected]). Vîrlan Cristina-Mihaela – ”Gheorghe Asachi” University of Iași, Bd. D. Mangeron nr. 63, 900356-Iași,

Romania (corresponding author to provide phone: +40-754-537889; e-mail: [email protected]).

http://www.apavital.ro/



DOI: 10.2478/ouacsce-2018-0007

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Modern Concepts for Constructive Solutions in

Dobrogea

Gabriela Draghici, Ana Maria Maican

_____________________________________________________________________

Abstract – In the summary published at the international conference WATER

2018, entitled "Modern concepts for constructive solutions in Dobrogea" [11], the

authors briefly referred to the theoretical considerations and the case study on the

concept of a "passive house" in the Dobrogea region - Romania, Constanta county,

more precisely in the Mangalia area. In this article we will present this subject in

great detail.

Keywords – constructive system, geothermal energy, passive house, thermal bridge

_____________________________________________________________________

1. INTRODUCTION

In this chapter we will present the general elements regarding the used concepts,

which were worked on in the case study presented in the second chapter.

1.1. Describing the concept "Passive House/Building"

Human society, in its evolution, has forced the increase in quality requirements on the

concept of "construction". Increasing the level of quality has, however, led to an increase in

conventional energy consumption, both in the manufacturing process and later in the post-

use process.

Thus, the necessity of conceiving and developing sustainable constructive systems has

emerged to capitalize on the local energy potential of each region. In this context, the

concept of "passive house" has also been developed.

"Passive House" is the building that respects the principle of "almost zero energy

consumption," as it can be seen that in this case the energy consumption for heating the

house can be reduced by up to 75% compared to the consumption for a conventional

building [1]. This type of building is characterized by the following parameters:

- high thermal comfort - constant temperature throughout the building, without risk

of airflow or dampness;

- indoor air quality - maintained by the existing ventilation system

High energy efficiency certified by the PH standard [1], the standard for the world's

highest energy efficient buildings.

The initiative to define a concept called "passive house" first appeared in Germany,

based on the principles developed by Dr. Wolfgang Feist. These principles materialized by

building the first passive house prototype. Subsequently, based on these principles, the

Passive House Institute was founded and the PH standard was developed. [1]


At the moment, in the EU level [2], there is a legislative package, as follows:

Directive 2012/27 / EU of the European Parliament and of the Council of 25 October

2012 on energy efficiency, amending Directives 2009/125 / EC and 2010/30 / EU and

repealing Directives 2004/8 / EC and 2006/32 / EC (OJ L 315, 14.11.2012, p. 1). [2]

Directive 2010/31 / EU of the European Parliament and of the Council of 19 May

2010 on the energy performance of buildings (OJ L 153, 18.6.2010, p. 13). [2]; Directive

2010/31 / EU required the Commission to carry out a review by 1 January 2017, building

on the experience gained and progress made during the implementation of that Directive

and, if necessary, presenting proposals. [2]

The Directive 2010/31 / EU, which entered into force in July 2010, have the role of

strengthening energy efficiency requirements for the application of minimum requirements

for the energy performance of new buildings.

1.2. Presentation of the concept „Structural system”

The concept of a structural system refers to the structure of resistance of the

construction, together with the exterior enclosures and the building architecture. Also the

structural system includes the materials used to build the construction.

The structural system can be seen from the viewpoint of tensions and actions that

manifest themselves in a structure, as presented by conf. Florin Onea Tepes in his article

[3]. Also, the structural system can be defined by the chosen materials and the architectural

design solutions found to achieve the chosen purpuse.

1.3. Presentation of the concept of „Thermal bridge” si „Thermal resistance of the

external wall”

The thermal bridge, in the case of a building element, is identified by an unevenness

of the transmitted heat flow, meaning the more intense transfer of thermal energy through a

certain area of that element. It is characterized by significant heat losses in the area.

Thermal losses occur due to the composition of the material from which the element is

made and, last but not least, due to a defective execution. [4]

The thermal resistance of the outer wall is defined by the relation [4]:

𝑅𝑃𝐸 = 𝑅𝑖 + 𝑅𝑒 + ∑ 𝑅𝑘𝑘 =1

𝛼𝑖 +

1

𝛼𝑒+ ∑

𝛿𝑘

𝜆𝑘𝑘 (1)

unde:

α_i [W/m2K] = Convective thermal transfer coefficient at the inner face of the

wall;

α_e [W/m2K] = Convective thermal transfer coefficient at the exterior face of the

wall;

δk [m] = the thickness of the wall layer k;

λk [W/mK] = the thermal conductivity of the wall layer k;

Equation (1) is defined in the C107-2002 design and calculation normative group and

together with other adjacent relationships was used in the calculation of the case study

parameters.


1.4. Presentation of the concept „Geothermal energy”

It is known from the published literature that the temperature, inside the Earth, rises

towards the center. Geothermal energy is a form of renewable energy, obtained from the

heat accumulated in the rocks and in the fluids that fill the pores of the rocks. Thus, steam

and hot water are trapped in volcanic and tectonic areas - the tectonic plate joint areas and

initially used only in the form of natural springs and thermal baths [5].

Geothermal energy is presented in two forms [5], as:

low temperature – specific for any part of the earth; it has been shown that it

increases in depth by 3℃ at enery 100 m;

high temperature – specific to volcanic zones, the drilling depth being very high,

reaching up to 10.000 meters deep;

Currently, due to the development of capture technology, the use of geothermal

energy can be expanded to a dual purpose, both for heating homes and for producing

electricity.

Figure no. 1 presents the map with the favorable areas for geothermal energy.

Fig.1 The map showing the favorable areas for geothermal energy [6]

"The potential of solar radiation" refers to the capacity of capturing solar radiation in

a certain geographical area. From this point of view, Romania is divided into three areas of

particular potential, thus [7]:

The first area, wich includes the areas with the highest potential, covers the region of

Dobrogea and a large parte of the Romanian Plain;

The second area, with a good potential, includes the North of Romanian Plain, the

Getin Plateau, the Subcarpathians of Oltenia and Muntenia, a large part of Danube

Plain, the south and the center of the Moldovian Plateau and the Plain and Western

Hills and the Western Plateau of Transylvania, where the value of solar radiations are

between 1300 şi 1400 MJ / m2;

The third area, with a moderate potensial, has less than 1300 MJ / m2 and covers most

of the Transylvanian Plateau, the northen Moldavian Plateau and the Carpathian

Rama[7]


Figure no. 2 presents the map of solar radiations.

Fig. 2 The map of solar radiations [8]

2. DESCRIPTION OF THE THEORETICAL MODEL

Nowadays, the world economy relies heavily on energy that comes from non-

renewable energy sources such as nuclear power or the energy generated by burning fossil

fuels (crude oil, coal, natural gas). Due to the fact that these energy sources are limited to

the existence of the respective deposits and their extraction, processing and transport to

consumers implies additional costs and some negative influences on the environment, it

should be paid more attention to the study of renewable energies.

The „Passive House” represents a concept that incorporates the characteristics

necessary for a modern, ecological, economic lifestyle, as: efficiency, comfort,

sustainability, inovation and accesibility.

A passive construction can use the resources it benefits in order to be energy-

independent. A building that can be framed within this term must produce at least the

amount of energy it consumes.

The technologies by which energy independence can be achieved, vary from one

case to another, so each building has its peculiarities depending on the area in which it is

located and depending on the meterials it is built with.

Regarding the structural system, used for the passive house model, two systems will

be compared, one is a structure formed by reinforced concrete frames with brick masonry and

the second one is metallic structure with exterior walls made of sandwich panels.

Considering the potential of the area, in order to ensure the energy efficiency of a

building located in Constanta County, Mangalia area, we will study the energy production

solutions using photovoltaic solar panels and using geothermal energy. In both situations,

the exterior walls are finished by applying the architectural "wall with solar energy

reservoir", a solution described in extenso by the authors Daniela Enz and Robert Hastings

in the book "Innovative Wall Building". (Daniela Enz, Robert Hastings - Innovative Wall

Constructions, Matrixrom Publishing House, 2012, pages 38-46).

The system consists of several layers, on the outer face with wooden lamellas. The

system is balanced for the façade because during sunny days, the sun is capturing through

the wood and the solar glass, component part, and in cloudy days or night period it

gradually releases the accumulated heat. This maintains an almost constant temperature

inside the enclosure regardless the temperature variation.[9]


The parameters characterizing the two types of structures are presented in Table no.1.

Tabel 1 The properties of the two types of structures Properties Type 1 Type 2

Resistance structure Reinforced concrete frames

with brick masonry

Metallic structure with exterior

walls made of sandwich panels

Foundations Reinforced concrete beams Insulated under pillars, stiffened

by concrete beams

Roof Uncirculated terrace Metal framing and cover -

sandwich panels

The usable area 1105,20 mp

The developed area 1498 mp

Building volume 3962,70 mc

The building cover surface 1365,02 mp

The heated surface 1105,20 mp

The heated volume 3205,08 mc

The surface of opaque walls 354,16 mp

Glazed surface 278,47 mp

No. of persons 64


3.1. Calculation of the thermal resistance of an outer wall for brick-built concrete frames

Table 2 Parameters for the calculation of heat transfer and transfer resistance, in case of

frame structure [10]

Element Material

thickness ʎ αi αe Ri Re R R ele-

ment

U Ele-

ment

m W/ mK W/

mpK

W/

mpK

mpK/

W

mpK/

W mpK/W

mpK/

W

W/

mpK

External walls

with wall system with

solar energy

reservoir

Exterior plaster 0,005 0,92

8 24 0,125 0,042

0,005

8,503 0,117 Insulating layer 0,08 0,04 2

Brick 0,25 0,04 6,25

Interior plaster 0,03 0,84 0,036

Floor on the

ground

Concrete screed 0,05 1,16 0,043

3,224 0,310

Concrete 0,1 1,74 0,057

Polystyrene 0,1 0,04 2,500

Ballast 0,25 0,7 0,357

Soil 0,2 2 0,100

Uncirculated

terrace

Interior plaster 0,03 0,84 0,036

5,505 0,182

Concrete 0,15 1,74 0,086

Underlay 0,015 0,17 0,088


Underlay 0,01 0,17 0,059


Double-

glazed

windows

(with double-

glazed

windows with

air layer)

0,570 1,754


The calculation was performed by applying equation (1). The data taken into

consideration for the study of the whole solution is presented in Table no. 2 [10]

In this case, according to the equation (1): R PE = 8,503m2K/W.

3.2. Calculation of the thermal resistance of a metallic structure with outer walls made of

sandwich panels

The calculation was performed by applying equation (1). The data taken into

consideration for the study of the whole solution is presented in Table no. 3 [10]

Table 3 Parameters for the calculation of heat transfer and transfer resistance, in case of

metallic structure [10]

Element Material

thickness

ʎ αi αe Ri Re R R ele-ment

U Ele-ment

m W/ mK W/

mpK

W/

mpK

mpK/

W

mpK/

W

mpK/

W

mpK/

W

W/

mpK

External walls

with wall system with solar energy

reservoir

Plasterboard 0,0125 0,39

8 24 0,125 0,042

0,032

2,544 0,393 Insulating layer 0,08 0,04 2,000

Sandwich panel 0,10 0,29 0,345

Floor on the ground


3,224 0,310

Concrete 0,1 1,74 0,057


Ballast 0,25 0,7 0,357

Soil 0,2 2 0,100

Roof

Plasterboard 0,0125 0,39 0,032

1,794 0,557 Mineral wool 0,05 0,04 1,25

Sandwich panel 0,10 0,29 0,345

Double-glazed

windows (with

double-glazed

windows with

air layer)

0,570 1,754

In this case, according to the equation (1): R PE parter = 2,544 m2K/W

Sandwich panels embedded in the "wall with solar energy reservoir" system have

some important features, centralized by the authors, but not presented in this article due to

lack of space.

3.3.Establishing the power supply system

From the study of the potential of solar radiation and the study of geothermal energy, for

the Dobrogea region, namely the Mangalia area, it was established that geothermal energy is

used for heating, and solar energy is used to produce hot water. The building will be equipped

with a ventilation system that will adjust the temperature of the indoor air and its capacity.

Currently, the power supply will also be made from the national system. It is

mentioned that the installation for capturing and producing heat from geothermal energy

can be designed also with the equipment related to the production of electric power. If the

Romanian legislation does not allow this to be achieved, then for the production of

electricity, the possibility of using wind energy, which also has a great potential in

Dobrogea, will be studied.


4. CONCLUSIONS

Passive houses, as it can be seen from this case study, can represent a viable, future

solution for the Dobrogea - Romania area. Furthermore, Directive 2010/31 / EU of July

2010 provides, among others, that by 31 December 2020 all new buildings must have

almost zero energy consumption. [2]

In this regard, in Romania, has been developed the "Plan to Increase the number of

buildings with almost zero energy consumption" issued by MDRAP [12], a plan for

imposing taxes on new buildings with different functions related to the maximum primary

energy consumption from conventional sources [kwh /mp, year] and CO2 emissions into the

atmosphere [kg /mp, year] as a result of the operating precesses of the buildings.

It is demonstrated and reconfirmed that the "passive energy house" system uses

alternative energy sources, materials and environment-friendly installation systems. The

maintenance costs, during their existence, as well as the waste they generate, are lower

compared to the costs of a similar classical building. In this way, although the costs for the

basic investment may be higher, by 25%, compared to the cost of a similar classical

construction, they are justified by the lower costs during the exploitation period.

Construction systems in the civil engineering industry must be designed in such a way

that the resulting buildings are compatible with the materials used, the building systems and

the energy supply system - to obtain a passive building.

5. REFERENCES

1 PHI(Passive House Institute) - https://passivehouse.com/

[2]. http://buildup.eu/en/node/9657 - The European portal for energy efficiency in buildings

[3]. Tepes Onea Florin, Tudorache Daniel (2017) „The nonlinear Analysis of the Seismic

Response of a reinforced Concrete Structure, Subjected to a Statically Equivalent Action”,

Bulletin of the Polytechnic Institute of Jassy,

http://www.bipcons.ce.tuiasi.ro/Content/ArticleInformation.php? ArticleID=604, Tomme:

63 (67)| Fascicle: 3, pg: 25-32

[4]. Grupa Normativelor de Proiectare si calcul C107-2002

[5]. Horia Necula, Adian Badea (2013) „Surse regenerabile de energie”, Editura Agir

[6]. www.econet-romania.com/

[7]. http://www.minind.ro/domenii_sectoare/energie/studii/

[8]. http://energonatur.ro/de

[9]. Daniela Enz, Robert Hastings (2012), Constructii innovative de pereti, Editura

Matrixrom

[10]. Stefanescu Dan (2012), Manual de proiectare higrotermica a cladirilor, Ed Societatii

academice „Matei-teiu Botez”

[11]. Draghici Gabriela, Cazacu Brandusa-Gabriela, Maican Ana Maria (2018), Abstract

„Modern concepts for constructive solutions in Dobrogea”, http://revista-constructii.univ-

ovidius.ro/conferinte/ index.php/water

[12]. Ministerul Dezvoltarii Regionale si Administratiei publice, http://www.mdrap.ro/

________________

Note: Gabriela Drăghici - Ovidius University of Constanta, Bd. Mamaia nr. 124, 900356-Constanta, Romania

(corresponding author phone: +40-241-619040; fax: +40-241-618372; e-mail [email protected])

Maican Ana Maria –masterand engeneering, Ovidius University of Constanta ([email protected])

http://buildup.eu/en

http://www.minind.ro/domenii_sectoare/energie/studii/potential_energetic.pdf


DOI: 10.2478/ouacsce-2018-0008

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Determination of the Basic Force-Displacement on

the Top in the Case of the Structure with Reinforced

Concrete Frames P+6

Florin Ţepeş Onea, Marian Dragomir

_____________________________________________________________________

Abstract – The theme of the paper is to design the capacity of a P + 6E

construction with reinforced concrete frame structure and determination of the basic

force-displacement on the top. Drawing the cutting force - the displacement at the top

requires a non-linear bias of the pushover type.

The non-linear static calculation is used in the displacement-based design

methodology, in which lateral displacements are considered the main parameter for

characterizing the seismic response of the structures.

Keywords – non-linear static calculation, reinforced concrete frame structure,

seismic response

_____________________________________________________________________

1. INTRODUCTION

The load given by a strong earthquake seeks to create an appropriate mechanism to

release earthquake-induced energy through deformation energy. This mechanism is initiated

by the appearance of plastic joints in beams and columns.

- the order of appearance of the plastic joints is followed. The appearance of these

plastic joints in columns is not acceptable but at the lower ends of the columns at the base of

the structure and at the last level.

- by pushing the structure and the appearance of the plastic joints, the structural strength

reserve (redundancy) of the structure is followed, the structure is not avoided and the structure

remains at the level of the Life Safety(LS)performance.

- the bilinearization of the capacitance curve determines the able lateral force of the

structure (Fy) and the overall ductility of the structure μ = αu / α1.


The research building is a P + 6E floor structure with reinforced concrete structure,

occupying a rectangular surface of 16,50 x 35,00 m in plan. The building is located in

Bucharest.

The basic objective of the current type of seismic design is to provide the most

advantageous structural energy dissipation mechanism. In the case of a structure with

multiple degrees of freedom, not all elements have to highlight a ductile behavior.


Fig. 1 Force-displacement curve for plastic joints with automatically assigned properties

The properties of the plastic joints are automatically determined by FEMA 356

specialized computing programs. For coupled and non-coupled plastic joints for each

degree of freedom / effort, it is necessary to define a force-displacement curve (bending-

rotating) with five points : A, B, C, D, E, F (Fig. 1)

The meaning of these points is as follows:

-pointA = the origin of the curve

-point B = plastification limit

-point C = ultimate capacity for static non-linear calculation

-point D = residual capacity for static non-linear calculation

-point E = complete failure

IO= (Immediate occupancy)

LS= (Life safety)

P= (Collapse Prevention)

In order to be able to perform a non-linear calculation in a first phase, a linear

calculation was made to determine the moments capable of the sections and, implicitly, the

reinforced steel used. These data will be used later in the nonlinear calculation.

The section through the building is shown in Figure 2 and in Figure 3 the calculation

model.

Fig. 2 Building plan


Fig. 3 Structure calculation model

The steps taken in the first phase are the assessment of loads, the pre-dimensioning of

the elements, the evaluation of the seismic action, the checking of the lateral displacements,

the calculation of the reinforcements. For example, fig. 4 shows the reinforcement areas for

a transverse frame.

Fig. 4 Longitudinal reinforcement area transversal frame beams C

The value of the longitudinal beam area of the beams and pillars in these tables is the

input value in the non-linear calculation of the stress-determining structure (Mrd) according

to the average strength of the concrete and steel.

Non-linear static calculation was performed using the ETABS program.

The vertical distribution of lateral forces is made by two different distributions,

namely:

-a distribution in which the lateral forces are proportional to the masses

(acceleration is constant in height ) ip.1.


-a distribution resulting from modal analysis for the predominant vibration

mode; a simplified triangular distribution can be accepted.ip.2

Table.1 Determining the displacements imposed on the structure

T[s] Sde[m] c Sdi[m] d[m]

IP I dir X 1.117 0.233 1.3943 0.3242 0.42

dir Y 1.032 0.198 1.5165 0.3010 0.39

IP II dir X 1.117 0.233 1.3943 0.3242 0.32

dir Y 1.032 0.198 1.5165 0.3010 0.30

The steps taken to achieve the calculation model are as follows:

-calculation of moments capable of considering the average strength of steel and

concrete.

-evaluation of the displacement requirement for the system with an equivalent degree

of freedom from the seismic response spectrum, depending on its rigidity and strength

characteristics

-evaluation of the displacement requirement for the real system based on the

requirement to move the system with a degree of freedom

-apply the horizontal load until the travel requirement value is reached

-verification of the plastification mechanism, made evident by imposing the

displacement requirement of the structure. It determines the relative displacements of the

level, the joints of the plastic joints and verifies their enrollment within the permissible

limits. The ratio αu / α1 is also determined and the behavior factor is correctly chosen to

design the structure.


After performing the calculations by pushing the structure up to the target

displacements, the following force-displacement curves were obtained:

Fig. 5 Pushover curve X direction (hypothesis1)


Fig. 6 Pushover curve Y direction (hypothesis 1)

Fig. 7 Plastic joints step 17


The drawing of the plastic joints at the moment of reaching the displacement

requirement allows to verify the realization of the design conception of the hierarchy of the

resistance capacities of the structural elements according to the mechanism of dissipation of

the desired energy.

At step 17, the target node located on the roof, reaches a maximum displacement of

15.5 cm, X direction , hypothesis 1.

At step 24, the target node located on the roof reaches a maximum displacement of

15.8 cm, Y direction, hypothesis 1.

At the capacity curve in the X direction in hypothesis I, it is observed that by bi-

linearization of the curve, the first plastic joint (corresponding to the first curvature stiffness

reduction) occurs around at a capable lateral force (Fy) of 7479 kN. The design seismic

force is 3838.10 kN, so the coefficient of over-resistance due to the design resistances of

the materials is 1.94.

The ratio of αu / α1 used for the assessment of seismic forces is 1.35. According to

the curve, the αu / α1 ratio (ductility of the structure) results from 2.77, higher than the one

evaluated; consequently the behavior factor q will be higher. This can be considered as a

safety factor with a suitable value for the earthquake design situation.

Fig. 8 Plastic joints step 24

At the Y curve in hypothesis I, it is observed that by bi-linearization of the curve, the

first plastic joint (corresponding to the first curvature stiffness reduction) occurs around a

8643.20 kN basic force. The design seismic force is 3838.10 kN, so the coefficient of over-

resistance due to the design resistances of the materials is 2.25. The ratio of αu / α1 used for

the assessment of seismic forces is 1.35. According to the curve the ratio is 2.90, higher

than the one evaluated; consequently the behavior factor q will be higher. This can be

considered as a safety factor with a suitable value for the earthquake design situation.


4. CONCLUSIONS

The general safety requirement is: requirement <capacity and can be expressed in

different sizes: displacements and deformations, efforts.

Table 2 Rotation

I-X II-X I-Y II-Y

STORY7 0.0019 8.31E-04 0.0018 0.0006

STORY6 0.0023 1.19E-03 0.0023 0.0010

STORY5 0.0029 1.66E-03 0.0029 0.0014

STORY4 0.0030 2.12E-03 0.0030 0.0019

STORY3 0.0030 2.40E-03 0.0029 0.0022

STORY2 0.0027 2.33E-03 0.0025 0.0022

STORY1 0.0016 1.61E-03 0.0015 0.0015

θra 0.03

In all cases the values of the rotation at the floor are below the 3% code value.

From the paintings presented that the structure is of the "low beams-strong columns"

type, the plastic joints in the columns only appear at their base, which is allowed by

normative.

It is noticed that the structural mechanism of seismic energy dissipation operates

according to the norms in the sense that it releases the accumulated energy from the

earthquake, by the plastic deformations reaching the level of performance "immediate

occupation" and "life saving".

It is noted that in hypotheses II in both directions the force cutter is higher exactly as

in the procedure described by the normative P100; in the hypotheses I, the basic moment at

the base of structure is higher, on the bouth directions.

From the analysis of capacity curves, it can be noticed that the structure has large

reserves and can receive a severe earthquake.

It is noted that the P100-1 / 2013 rotation evaluation procedure consisting of the

amplification of displacements obtained from a linear elastic calculation under the design

seismic forces, amplified by c * q, leads to higher values, in some cases, much higher than

the specific seismic requirements.

An expected and desirable behavior is observed in the direction of forming the plastic

joints at the end of the beams. There are no plastic joints that do not lead to progressive

collapse.

Only a few plastic joints exceed the CP (collapse Prevention) limit, but the structure

has enough reserves to redistribute the efforts that can not be taken up by the dissipative

elements that have come out of work.

5. REFERENCES

1 Cod de practică seismică P100-1/2013

[2] T.Postelnicu, I.Damian, D.Zamfirescu (2012), Proiectarea structurilor de beton armat

în zone seismice ,Editura MarLink, Bcureşti


[3] T.Paulay,H.Bachman,K.Moser (1997), Proiectarea structurilor de beton armat la

acţiuni seismice, Editura Tehnică,Bucureşti

[4] I.G.Craifăleanu (2016), Introducere în calculul neliniar al structurilor la acţiuni

seismice cu programul SAP2000,Matrixrom

[5]SR-EN1992-1-1 Eurocod 2Proiectarea structurilor de beton armat partea 1-1. Reguli

generale pentru clădiri.

__________________

Note:

Ţepeş Onea Florin - Ovidius University of Constanta, Bd. Mamaia nr. 124, 900356-Constanta, Romania (corresponding author to provide phone: +40-241-619040; e-mail: [email protected]).

Dragomir Marian - (design engeneering, e-mail: [email protected]).


DOI: 10.2478/ouacsce-2018-0009

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Determination of Global Efficiencies of Variable

Speed Pumps within Water Supply Systems

Daniel Toma, Cristina-Mihaela Vîrlan and Nicolae Marcoie

_____________________________________________________________________

Abstract – The energy transformations involved in the operation of the pumping

installations are carried out by pumping aggregates consisting of an electric motor

and a pump. In order to provide a full adaptation to the users’ variable demands,

variable speed motor driven pumps are used on networks (such motors being

equipped with frequency converters). The paper presents a method for determining

the global efficiency of a frequency converter-asynchronous motor-pump group. The

method has been implemented at the Chiriţa Pumping Station, main facility within

the Iasi City water supply system.

Keywords – efficiency, pumps, static frequency converters, water supply

_____________________________________________________________________

1. INTRODUCTION

As regards the pumps operation the pursued objective is to maximize the overall

efficiency of the electrical energy-to-hydraulic energy conversion process, while complying

to functional restrictions imposed by the users of the hydraulic system in which these are

integrated. The achieving of this goal requires a permanent control of the assembly's

performance by measuring the status parameters which are involved in the analysis [1].

Usually pumping stations serve networks in which demands vary over time between a

minimum flow rate and a sizing flow rate. The variation of a pumped flow can be provided

by means of two methods [2]:

by modifying the system’s head characteristic, reduced at delivery’s origin by:

modifying of head loss characteristic on pumps communications;

modifying of pumps’ own head loss characteristics;

modifying of the resulting characteristic of a pumping group equipped

with parallel coupled pumps;

by an intermittent pumping and flow compensation, by providing the head

demanded by network.

In pumping installations within water supply systems, the changing of a pump

characteristic is achieved by varying the speed of the pumps rotors, this being obtained by

variable speed drives (on serial-built asynchronous motors), by means of static frequency

converters. This control system can be efficient only if the subsequent power savings

(obtained on a normed time of pump operating) will cover al least the costs of such pump

driving systems.


2. THEORETICAL ASPECTS

In order to study the efficiency of variable speed pump drives there is need to take

into account the efficiency modification for three components [2]:

efficiency of the pump (tb );

efficiency of the static frequency (csf );

efficiency of the converter-driven asynchronous motor (ma ).

2.1. Method for determining the global efficiency of the pumping group: static frequency

converter – asynchronous motor – pump

The diagram of a variable speed pumping group driven by static frequency converter

is shown in Fig. 1.

Fig. 1. Diagram of a variable speed pumping group driven by static frequency converter

(static frequency converter - asynchronous motor - pump)

The efficiency of a pumping system (that is, pump + asynchronous motor) driven by

converter is given by equation (1):

2E

HAP

P

P (1)

The efficiency of a variable speed pumping group (pump driven by static frequency

converter) is given as the equation (2):

1E

HGP

P

P (2)

The hydraulic power, given in kW, and exerted by pump towards the fluid is to be

computed with equation (3):

QHPH 81,9 (3)


The electric power absorbed by the static frequency converter is given by (4):

1111 cos3 IUPE (4)

where: U1 – voltage of the current that feeds the static frequency converter; I1 – intensity of

phase current, corresponding to voltage U1; 1cos – power factor.

The electric power absorbed by pump results from (5):

2222 cos3 IUPE (5)

where: U2 – voltage of current that feeds the driving motor; I2 – intensity of current on

phase corresponding to voltage U2; 2cos – power factor.

Thus, the efficiency of the static frequency converter shall be given by (6):

1

2

E

Ecsf

P

P (6)

The diagram of a pumping group, provided with variable speed drive, which uses

direct grid supplied power (without a static frequency converter), is shown in Fig. 2.

Fig. 2. Diagram of a static frequency converter - asynchronous motor - pump

(power supplied directly from the grid)

In this case, the pump’s efficiency is computed with equation (7):

3E

HAP

P

P (7)

3333 cos3 IUPE (8)

where: U3 – voltage of current that feeds the driving motor; I3 – intensity of current on

phase corresponding to voltage U3; 3cos – power factor.


3. CASE STUDY: THE CHIRIȚA PUMPING STATION

By using the above-shown method it has been possible to compute the global

efficiency of a pumping group having the configuration: static frequency converter -

asynchronous motor - pump. Measurements have been carried out in the “CITY” pumping

plant, a component of the main “Chiriţa” pumping station, located in Iaşi City (Photo 1).

The “CITY” pumping plant includes (2+1) WILO ASPV250C pumps featuring the

next parameters: Q = 300 l/s and H = 48 mWC (Photo 2). The P1, P2 and P3 pumps are

connected in parallel and are driven at nominal or variable speed by an ATV61HC22N4

static frequency converter (Photo 3), that is switcheable on all three pumps.

Photo 1. The Chiriţa

pumping station

Photo 2. The “CITY”

pumping plant

Photo 3. The static

frequency converter

In the first phase, by measurements performed in direct coupling mode (without static

frequency converters), the pumps’ efficiencies ηAP were computed (for pumps within the

“CITY” installation), the efficiencies depending on flows pumped towards the network.

The flow variation was achieved by closing the valves on the pumps discharge lines.

The flow rates, corresponding to different operating modes, were visualized by means of

SCADA software, software used for surveillance, control and data acquisition [3].

The pressures on the pumps’ suction and discharge lines were read on the pressure

gauges connected to the system pressure outlets. The electrical parameters were determined

using the FLUKE 435 energy analyzer. All parameters involved in the analysis were

measured after the stabilization of the operating mode.

The measurements results were centralized in Table 1.

Table 1. Pumps’ efficiencies, AP , within the “CITY” installation, in the case of direct

grid power supply

Pump Q

(m3/h)

H

(m)

U3

(V)

I3

(A)

cos 3

(-)

PH (kW)

PE3 (kW)

AP

(%)

P1

1350 39,11 230 364 0,87 143,87 218,51 65,84

1283 41,49 230 360 0,87 145,04 216,11 67,12

1113 49,50 230 340 0,86 150,12 201,76 74,40

912 54,29 229 337 0,86 134,93 199,11 67,77

770 56,41 230 297 0,85 118,36 174,19 67,95

509 58,11 230 269 0,84 80,60 155,91 51,69

359 59,52 229 242 0,83 58,23 137,99 42,20


183 60,99 229 220 0,80 30,41 120,91 25,15

73 61,44 230 215 0,80 12,22 118,68 10,30

P2

1335 36,86 229 360 0,86 134,10 212,70 63,05

1263 40,05 228 357 0,86 137,85 210,00 65,54

1180 42,84 229 355 0,86 137,74 209,74 65,67

952 49,71 229 315 0,85 128,97 183,94 70,11

714 54,11 230 287 0,84 105,27 166,35 63,29

420 56,67 230 250 0,83 64,86 143,18 45,30

230 57,52 230 226 0,81 36,05 126,31 28,54

170 58,49 230 220 0,80 27,10 121,44 22,31

Figure 3 shows the correlation ),( oAP nQf for each analyzed pump from the

“CITY” pumping installation.

a - AP1 pump b - AP2 pump

Fig. 3. Pumps efficiency characteristics, AP , as function of pumped flow Q, in the case of

a direct grid power supply (at no rated speed)

By supplying power via the static frequency converters at various frequencies, there

have been determined for various speeds ni, the efficiencies of the pump+motor pumping

systems (APi ), the efficiencies of the pumping groups (frequency converter –

asynchronous motor – pump, GPi ) and the efficiency of the static frequency converter,

this in function of the flows pumped towards the network.

The flows variation has been achieved by shutting down the pumps’ discharge valves.

The conveyed flows (corresponding to the various operating regimes) have been viewed on

the SCADA software (software that surveys and controls the plant and also acquires

process data) [4]. Pressures on the pumps’ suction and discharge mains have been read on

pressure gauges (mounted on the plant’s pressure ports).

The frequency converter input electric parameters have been recorded with a FLUKE

435 power quality analyzer and all converters’s output electric parameters have been read

on its menu. All parameters and factors involved in this analysis have been recorded after

the stabilization of operational regimes. Measurements have been carried for 4 different

frequencies. Photo 4 shows the reading process, readings being carried on the frequency

converter’s display, for the 4 frequencies used for this study.

The measurements results have been summarized in Table 2.


a - f = 47,5 Hz

(n =1425 rpm)

b - f = 45,0 Hz

(n =1350 rpm)

c - f = 44,2 Hz

(n =1325 rpm)

d - f = 40,0 Hz

(n =1200 rpm)

Photo 4. Supply frequencies for the P1 pump motor

Ta

ble

2.

Pu

mp

s ef

fici

enci

es,

ηA

P,

pu

mp

ing

gro

up

s ef

fici

enci

es,

ηG

P,

and

sta

tic

freq

uen

cy c

on

ver

ters

eff

icie

nci

es,

ηcs

f, w

ith

in t

he

“CIT

Y”

inst

alla

tio

n,

as a

fun

ctio

n o

f sp

eed

n


Figure 4 shows the relations ),(1 iAP nQf and ),(1 iGP nQf for each

pumping group inside the “CITY” pumping plant.

(a) - )1425,(, 11 QfGPAP (b) - )1350,(, 11 QfGPAP

(c) - )1325,(, 11 QfGPAP (d) - )1200,(, 11 QfGPAP

Fig. 4. Efficiency characteristics for AP1 pump (pump+motor system) and GP1 pumping

group, as function of speed n and pumped flow Q, for motors driven by frequency

converters

4. CONCLUSION

By reviewing Table 2, it can be seen that the efficiency of the static frequency

converter depends on two parameters: the driving speed and the pumped flow. Table 3

shows the efficiencies as a function of the relative driving speed and the relative flow

corresponding to each speed.

This features values covering a range between 89,53 – 96,57 % for any relative speed

90,0/ onn and any conveyed flow. Corresponding to each speed, into the nominal

point, the efficiency values shall vary between 91 – 96 %. Lower efficiency values occur

when motor driving takes place at relative speeds 90,0/ onn and relative flows

30,0/ oQQ . The efficiencies of the pump+motor pumping systems ( AP ) and those for


the pumping groups ( GP ) are useful for determining the global efficiencies in pumping

plants and also for the economical and power consumption features of pumping processes.

Table 3. Efficiencies of the static frequency converter (csf ) as a function of the relative

flow Q/Qo, at various speeds n

Speed

n (rpm)

Relative

speed

n/no

(-)

Relative flow Q/Qo (-)

Efficiency of the static frequency converter csf (%)

1425 0,983 0,135 0,174 0,340 0,524 0,696 0,965 1,093 1,264

92,81 94,00 94,20 95,28 96,57 96,11 95,78 95,41

1350 0,931 0,129 0,369 0,552 0,765 0,958 1,052 1,215 -

91,86 92,87 94,23 94,80 94,19 93,93 93,50 -

1325 0,914 0,100 0,240 0,396 0,625 0,851 1,053 1,185 -

90,56 89,53 92,42 95,64 94,99 93,46 92,93 -

1200 0,828 0,127 0,301 0,516 0,721 0,916 1,055 - -

81,89 88,42 91,86 93,79 92,42 91,14 - -

6. REFERENCES

[1] Alexandrescu O. (2004), Maşini şi echipamente hidraulice, Editura Politehnium, ISBN

973-621-095-2, Iaşi

[2] Toma D. (2012), Cercetări asupra pompării apei cu mașini hidraulice cu turație

variabilă, Ph.D. Thesis, “Gheorghe Asachi” Technical University of Iași

[3] Sârbu G.C. (2017), Evaluation of measurement uncertainty in calibration standard

gravimetric installation for water flowmeters verification, 22nd

IMEKO TC4 International

Symposium & 20th International Workshop on ADC Modelling and Testing, Supporting

World Development Through Electrical & Electronic Measurements, pp. 471-475

[4] Sârbu G.C. (2016), Modern water flowmeters.Differential pressure flowmeters,

Proceedings of the 2016 International Conference and Exposition on Electrical and Power

Engineering, pp. 609-616

_____________

Note: Toma Daniel - “Gheorghe Asachi” Technical University of Iași, Faculty of Hydrotechnical Engineering,

Geodesy and Environmental Engineering, 65 Prof.dr.docent Dimitrie Mangeron Street, 700050-Iasi,

Romania (corresponding author to provide phone: +40-721-811373; e-mail: [email protected]). Vîrlan Cristina-Mihaela - “Gheorghe Asachi” Technical University of Iași, Faculty of Hydrotechnical

Engineering, Geodesy and Environmental Engineering, 65 Prof.dr.docent Dimitrie Mangeron Street,

700050-Iasi, Romania (e-mail: [email protected]). Marcoie Nicolae - “Gheorghe Asachi” Technical University of Iași, Faculty of Hydrotechnical

Engineering, Geodesy and Environmental Engineering, 65 Prof.dr.docent Dimitrie Mangeron Street,

700050-Iasi, Romania (e-mail: [email protected]).


DOI: 10.2478/ouacsce-2018-0010

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Use of Modern Technology to Develop Investment

Housing Projects in Iraq

Ahmed Mohammed Teen, Ana Maria Gramescu

_____________________________________________________________________

Abstract – The problem of housing is one of the most important problems in

Iraq, especially with the increase in the rate of population growth which is one of the

highest rates in the world and after the great destruction that happened in Iraq

because of wars and terrorist acts, and here begins to think about the real solutions of

this crisis using modern technology and taking into account the feasibility of using

modern construction materials compared to the traditional method of construction.

Investors are seriously considering changing the traditional building style and

transition to modern building materials to increase quality, win a time, ease of

installation and achieve dimensional consistency with ease of internal and external

finishing work. The hot weather in Iraq requires real attention to the issue of thermal

insulation of buildings and therefore can use the advantage of modern materials to

increase thermal insulation and reduce in the energy consumption. This article sheds

light on the investment housing projects in Baghdad city.

Keywords – cost, investment, materials, technology, time

_____________________________________________________________________

1. INTRODUCTION

The housing sector is one of the most affected sectors in Iraq after the wars in Iraq

spanning 38 years, and from here investors began to invest in the field of housing, the

feasibility studies of projects focused on the determinants of financial, economic,

environmental and social.

While increasing the need for the development and expansion of all kinds of buildings

in Iraq it becomes necessary to consider the nature of the materials. In Iraq the temperatures

reached high levels is the highest in the world exceed 50°C .that huge rise in temperature

requires thinking about the use of new materials and modern technologies that contribute to

increasing thermal insulation and reduce the consumption in energy in a country already

suffering from an energy generation crisis. The insulation in most buildings makes by using

a primitive ways and often confined to the roof of buildings only.

The need for residential housing units increased to 4 million units in 2014 [1] in

addition to the need for commercial and industrial buildings, especially after the great

destruction on infrastructure because of the war. Most of buildings in Iraq not designed to

resist seismic loads and this increases the risk and hazard of buildings collapse these

building when strong earthquakes occur especially after increasing earthquakes in this area

between Iran and north of Iraq.

After all of the above it is necessary to move towards practical and economically


feasible alternatives. The feasibility of choosing the right style for constructing buildings is

not limited to choosing cost of construction only but depends on the control triangle (time,

cost, quality).

One of the most important factors in the success of construction projects is the time,

reducing the time of completion of the projects leads to rapid recovery of the value of the

project in addition to accelerating solution to reduce the crisis of residential and

commercials buildings.

The quality of the projects completed depend on the choosing of materials with high

effects in future on performance of origin in terms of performance in another functions like

a insulation, reduce the consumption in energy, keep to environment, and increase the

construction age and durability.

1.1. Most important problems of housing sector in Iraq

There are many problems related to the construction of residential complexes, which

directly contribute to reducing the technical value and economic feasibility of these

projects, important factors are:

• high in impletion cost,

• pollution,

• low quality,

• loss in HR management,

• increase in energy consumption,

• high in completion time,

• human resource management absence.

1.2. Common materials of construction in Iraq

a) Residential complexes:

Most of the residential buildings consist of concrete structures and a concrete roof,

usually ranging from 3 to 9 floors, most often.

The partitions makes by using a hollow block or bricks with a thickness 10- 24 cm. In

a few cases lightweight blocks are used (foam concrete blocks).

b) Stand-Alone Villa:

This type represents the majority of the types of residential complexes and arises

mostly using the strip foundations and then walls of the bearing-load walls using the bricks

or hollow concrete blocks and that depend of regions in Iraq. Every unit consists between

1-2 stories with a total area between 100-300 m2 in most cases.

Below is a table of building materials used in various areas of Iraq.

Table 1 Building materials used in Iraq

Region Material used in walls

North Hollow concrete blocks

Solid concrete block

West Clay bricks

Solid stones

South Clay bricks

East Clay bricks

Baghdad Clay bricks


In north, south, west and Baghdad zones are not used a concrete block because these

zones have high temperatures especially in summer.

Fig. 1 Building styles in Baghdad

Below is a traditional material used in various areas of Iraq

Fig. 2 Common materials in Iraq


2. INVESTMENT IN HOUSING COMPLEXES

Iraq is one of the most attractive countries to invest in housing, especially after the

increase in demand for housing units and the new tendency of the state to focus on building

residential complexes in an investment way.

Iraq's population is 38 million, according to the latest official statistics. Investors should

focus on time competition and reduce cost to meet the economic viability requirements of

investment in the housing sector. With the increasing investment companies operating in Iraq,

the need to achieve the main requirements for the success of the investment project is

increased by reducing costs, reducing the time of achievement and achieving customer

satisfaction, which means achieving high quality, in addition to the modern investment

requirements of increasing the operation of the plant and reducing the consumption of electric

power Water and environmental conservation requirements by reducing thermal emissions,

minimizing waste and using clean energy to save energy for those buildings.

Below is a total population in Iraq according to Iraqi Ministry of Planning, Central

Statistical Organization.

Table 2 Total Population in Iraq [1], Resource: ministry of planning

2.1. Iraq's need for residential units

Estimated the need for housing units in Iraq to 4,000,000 housing units, which

represents a very large number calls for thinking of urgent and quick solutions to alleviate

this problem, especially with the high rents prices significantly, which put great pressure on

citizens with low incomes.

The reliance on traditional methods of construction cannot solve the problem and do

not achieve the goal of solving this problem quickly, especially in terms of the time of

completion of these projects.

2.2. Contribution of new technology and Materials on improve management of

residential buildings

a. Reduce consumption of electricity

The problem of electricity is one of the most complex problems affecting the public

life of citizens, as the demand for electric power is increasing continuously with a large

power deficit of up to 12000 megawatts, while the output does not exceed 15000

megawatts and as shown below.


Fig. 3 Consumption of electricity in Iraq KWH [2], Resource: ministry of planning

The majority of the consumption of electric energy is in the share of residential

complexes, hence the role of modern technology in reducing the consumption of electric

power through the use of modern insulation materials contribute to reduce the consumption

of electric power in the country has one of the highest temperatures in the world exceed

sometimes 50 °C. The most important materials that help increase the thermal insulation

rate in residential buildings are:

Foam concrete:

Foam concrete is one of the most important materials that may have a significant

impact on improving the performance of construction projects in many ways. Its density

ranges from 200 to 1800 kg / m3. This helps reduce the load on the structure of the building.

Heat insulation of buildings significantly compared to other structural materials such as

bricks and concrete blocks.

Foam concrete is easy to transport and therefore makes work faster and less risky than

personnel safety.

Finishing works in construction will be much faster and easier compared to bricks and

other types of masonry masses.

Table 3 The typical values of thermal conductivity of foam concrete [3]

Prefabricated walls:

Precast or prefabrication concrete is one of the most important elements that lead to

improved performance in the stages of construction of residential buildings in the manner


of investment, which have significant benefits in increasing the efficiency of performance,

especially thermal insulation of buildings and thus reduce the consumption of electricity.

The use of foam concrete in prefabricated units has the great effect of increasing

thermal insulation by adding foaming materials during the process of precast concrete walls.

Insulated glass

Doors and windows in residential units are considered to be the most sources of

energy loss in buildings and houses. The windows contribute at least 34% of the loss of

energy and the doors contribute to loss of at least 40% of the total loss of energy, that

means doors and windows constitute a total 75% of the total value.

From this fact comes the importance of good insulation of doors and windows and the

most important question.

Below is one of the heat insulating glass models which increase the thermal insulation

ratio in addition to voice insulation.

Fig. 4 Insulated glasses [4], Resource: ar.drgreiche.net

b. Improve the time of projects completion:

The management of time is one of the most important challenges facing the

construction of residential complexes where most investment projects delayed delivery of

housing units because of the use of traditional means of construction and for several

reasons:

Increase the transport time

Increase the masonry time

Increase the finishing work time

While the use of modern technology and new materials to overcome significantly

delays in the time of completion of the project in addition to other advantages of the

modern materials, including the use of structural elements and the proportion of

manufacturing and foam concrete and other materials that lead to a reduction in the

completion time by a large percentage may exceed 15% of Total time of completion.


3. FACTORS AFFECTING TO INVESTMENT FOR HOUSING PROJECTS

The main objective for investors to invest in the field of housing is to achieve

profitability, and since the investment in this sector of the opportunities in Iraq, the

competition for the completion of these projects at a high level and that the realization of

the requirements of feasibility of the implementation of these projects based on several key

elements:

Cost of projects:

Many investment companies have been affected by their sales of residential units due

to the large competition for the most advanced companies in terms of using modern

technology cheaper than the traditional materials whose economic feasibility of using them

is not useful. The sale price of residential units are 400$/m² -1000$/m² according to the

quality and according to the materials used in the implementation of the work lightweight

materials such as foam concrete and walls filled with isolated materials increase thermal

insulation, in addition to its contribution to reduce dead loads and thus reduce the rebar and

reduce the space Structural sections, which in turn contributes to reducing the total cost of

housing units.

Time of completion:

The management of time in projects is one of the most important challenges facing

investors as the management of time risk takes a lot of effort and allocate an additional

budget for the total cost of the project because of the large number of labor and the use of

traditional systems in the implementation as the heavy construction blocks need a

considerable time for implementation in terms of transport and construction Terminations

and thus the need for more time. The value of the project's recovery is inversely

proportional to the project completion time. Therefore, the use of modern construction

techniques significantly reduces the length of time needed to complete the project. This

includes the use of prefabricated concrete walls and beams. The use of these techniques

greatly helps to reduce the completion time by 15-20 %.

Customers satisfy:

Quality management requires keeping abreast of the major developments in modern

building materials and harnessing them to develop building systems to achieve the highest

levels of comfort and prosperity for the customers and thus achieve higher profits and

achieve the feasibility of investment in those projects. The term quality is the true synonym

for customer satisfaction, and including reducing energy consumption through insulation

methods as well as reducing noise, fire protection and protection against natural hazard and

risks.

Environment requirements:

Construction works effect of thermal emissions, buildings represents 35% and 50% of

total emissions [5]. As a result, thermal emissions and pollution continue to end the life of the building,

and therefore alternative solutions must be found to reduce pollution and thermal emissions

and replace the traditional materials of construction to new materials that have few

emissions and which meet environment requirements, and away from substances harmful to

the environment and from these materials and finishes harmful material P.V.C and

formaldehyde, which is used as an adhesive, and vinyl material used in flooring [6].


Fig 5 Pollution and thermal emissions during the building cycle

4. CONCLUSION

The investment in the housing sector is one of the most promising areas in Iraq and

requires further development and study to achieve two important aspects of what is required

to manage investment projects in the field of housing:

First: To achieve the economic feasibility of these projects through the use of modern

materials and advanced technology in the construction to continue competition by reducing

the costs of these projects and reduce the time of achievement, which represents the most

difficult challenge for the investment companies and also achieve the high quality of origin,

which is customer satisfaction.

Second: Achieving the environmental requirements set by modern construction

regulations aimed at reducing pollution and thermal emissions throughout the life cycle of the

building. This is done using modern building materials that are environmentally friendly and do

not cause excessive thermal emissions outside the building. Most of the materials that reduce

emissions are natural materials. Concentration on water and air inside the building through good

cooling systems as well as the use of thermal insulation to reduce the consumption of electricity

consumed in the building and reduce thermal emissions, and the most important parts that

require thermal insulation walls Glass windows in addition to the roofs of buildings.

5. REFERENCES

[1] Ministry of planning, central Statistical Organizationhttp, Iraq, 2017

http://www.cosit.gov.iq/ar/2013-01-31-08-43-38

[2] Ministry of planning, central Statistical Organizationhttp, Iraq, 2017

http://www.cosit.gov.iq/ar/industrial/electric-water

[3] Qesm Al Wahat Al Khargah, New Valle Governorate, Egypt, 60M, 2017,

https://uae.makinah.net/ar/subject-details--165--26

[4] Dr. Jresh, DCI International, Egypt, 2018, ar.drgreiche.net

[5] Dr Hüdai Kara, Metsims Sustainability Consulting, Oxford OX2 7NL, United Kingdom

[6] http://www.startimes.com/?t=29310694

_____________

Note: Ahmed Mohammed Teen - Ovidius University of Constanta Doctoral School of Applied Sciences,

Constanta, Romania, (e-mail: [email protected]) Professor PHD Eng. Gramescu Ana Maria - Ovidius University of Constanta, Constanta, Romania

http://www.startimes.com/?t=29310694


DOI: 10.2478/ouacsce-2018-0011

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Behavior Analysis of Minarets at the Destructive

Factors Actions

Sever Suliman, Ana Maria Gramescu

_____________________________________________________________________

Abstract – Etymological minaret comes from the Arabian "manarat", meaning

"illumination place", "lighthouse", the term was taken in Turkish (minaret) and

French. The minaret is a particularly important component of a mosque, which is the

object of study of this article, analyzing environmental factors, especially water, which

acts on minaret materials located in the Black Sea area. The minaret is a high tower

built into the actual construction, from which muezin calls his believers to work. Due

to its visibility from distant horizons, it provides important information to visitors in

the region, namely the presence of Muslim believers in that area.

Keywords – minaret, mosque

_____________________________________________________________________

1. INTRODUCTION

From the architectural point of view, the minaret can have different shapes depending

on the location, and the period in which it is constructed by taking cylindrical, conical,

rectangular shapes. On the inside or outdoors there is a helical staircase that provides access

to the top where a balcony is provided around the minaret, from which the muezin makes

the call to the job. The number of minarets in a mosque may vary depending on the size of

the mosque (Istanbul's Sultanahmet Mosque has 6 minarets) (Fig. 1).

Fig. 1 Sultanahmet Mosque (www.travel.usnews.com)


As a rule in our country, a single minaret is built at the mosques, based on the cross-

shaped section of the square, then from a higher height to the circle section. The helical

staircase is located inside, providing access to the balcony.

The roof usually has a wooden shingle and the sheet metal. The dimensions of

minarets and construction materials and technologies vary according to the importance of

the mosque, and the period in which it was built. For example, at the Esmahan Sultan

Mosque in Mangalia built in 1573, the resistance structure is made of stone masonry, and

the minaret was about 30m high, but at the end of the 19th century because of a thunderbolt

the minaret suffered great damage, so it was completely restored reaching 15.5 m high.

Among the mosques with stone masonry minaret can be also mentioned the ones from

Babadag Gazi Ali Pasa Mosque (fig.3), Mosque from Amzacea, Main Mosque from

Medgidia (fig.4), Mosque from Tulcea (fig.7) , Mosque from Isaccea (fig.5), Mosque from

Macin, Cernavoda, Albesti, Cotu Vaii, Hunchiar Mosque from Constanta.

Fig. 2 Mosque from Babadag

Fig. 3 Mosque from Medgidia

Fig. 4 Mosque from Isaccea

Fig. 5 Mosque from Măcin

Fig. 6 Esmahan Sultan Mosque from

Mangalia

Fig. 7 Mosque from Tulcea


The stone masonry minarets are made of mortar and stone, and the outside is plastered

and finished. Inside plastering works are not done, the only interior finishing operations are

the grinding of the interior masonry. The central spindle and the steps are all made of stone

with variable dimensions. A special case is at the Mangalia Mosque (fig.6) where no binder

was used at the beginning to build the masonry but steel casts were cast in place in stone

holes.

Another material used for the construction of the resistance structure of the minarets

is the reinforced concrete, a material that has been used since the beginning of the 20th

century and can be found at the minarets of the mosques in Negru Voda (fig. 9), Tuzla, 23

August, Lazu, the Carol I Mosque in Constanta (fig. 8), Topraisar, Pecineaga. The exterior

finishing is achieved thanks to the special formwork that gives the final shape of the

minarets. Characteristic of reinforced concrete minarets, the inner diameter varies from

bottom to top from 120 cm to 100 cm and the wall thickness is 20 cm and the height is

approximately 30 m. The steps are also reinforced concrete being embedded in the walls of

the minaret and on the other side in the central spindle which is also reinforced concrete.

The roof has a wooden shingle, and the sheet metal, except for the Carol mosque, the roof

of which is made of concrete.

The characteristic dimensions of the steps of the minarets vary so that the height is

between 15-20 cm and the width between 20-30 cm.

Fig. 8 Carol I Mosque

Fig. 9 Minaret from Negru Voda Mosque


The destructive factors of the water enriching environment come from: groundwater,

meteoric waters, seawater, condensation.

Underground waters are a destructive factor requiring a thorough study to combat as

accurately as possible the destruction due to their action. Due to fluctuations in the

groundwater level, there is pressure on minarets' foundations, pressures that can lead to

tilting them or even worse when they collapse. Thus, for the detection of the groundwater

level in the minarets area, geotechnical studies will be carried out.


The meteoric waters are those waters that come from atmospheric precipitation:

water, snow. It is especially important to create a proper drainage system so that these

waters do not penetrate into the soil around the minarets foundation.

Marine waters are waters that act on the outer surface of minarets, with a very high

salt content affecting the constituent materials of the minaret.


A problem arising from the action of water is the exfoliation of the paint on the

outside of the minaret and the dampness appearance of the minaret.

Fig. 10 Mosque from Tulcea

The solution to counteract these destructive factors is to clean the exfoliated and

dampness areas in order to reapply the exterior paint and create a drainage system so as to

prevent maximum infiltration.

Fig. 11 Minaret from Babadag Mosque


Another problem is the collapse of the plaster as a result of infiltrations, the

appearance of vegetation on the minaret (Fig. 11). Solution: Removing the plaster,

removing vegetation and creating a proper drainage system.

Fig. 12 Mosque from Cernavodă

As a result of the drainage caused by the underground water at a very high level,

deformations of the minaret appeared (Fig. 12). Adopted solution: At the base of the

minaret, an reinforced concrete reinforcement system was built starting from the bottom of

the foundation. A reinforced concrete beam was built at the top and supported on a

reinforced concrete frame system inside the glazing (Fig 13).

Fig. 13 The structure inside the Mosque from Cernavoda

Another problem is the result of the action of meteoric waters, a phenomenon that is

visible. It can be seen how the water from the roof is infiltrated in the fissure (fig. 14) and

precipitation water infiltrates through the cracks between the window and glaf, thus

degrading the entire wall (Fig. 15). The solution to combat these rising is proper sealing of


windows to no water gets inside and creating a drainage system on the roof of the minaret

so that water does not keep above it.

Fig. 14 Minaret Eaves by Carol I Mosque

Fig. 15 Minaret inside by Carol I Mosque

4. CONCLUSION

The minaret is a very important part of a mosque. It is very important to combat as

much as possible the action of the destructive factors on these constructions, for their

preservation so that their exploitation can be accomplished without any problems.

6. REFERENCES

[1] Maria Barbu “Semiotica Arhitecturii sau Arhitectura ca Filozofie a Libertății” -

Monitorul Oficial RA 2012, ISBN 978-606-93015-2-4

[2] Bibliografia din Institutul Național al Patrimoniului – fișe monument istoric

[3] Lista monumentelor istorice – Direcția Județeană pentru Cultură Constanța

[4] Al-Coran, “Tafsir Pimpinan ar-Rahman” (Terj.) Șeicul Abdullah Basmeih. Jabatan Hal

Ehwal Islam Perdana Menteri, Kuala Lumpur

[5] Abu Bakar, S. (1984). “Keindahan dalam Kesenian Islam”. Kertas Kerja Seminar

Kesenian Islam

[6] Mehmet Ali Ekrem (1981), “Civilizația turca”, Ed. Sport turism

[7] Mictat A. Garlan (2011), “Metodologia cercetării etnopsihologice”, Ed. Lumen Iasi

[8] Headqarters of Dewan Bahasa Dan Pustaka, Kuala Lumpur: 6/2013

[9] Beg, MAJ (1981), “Arte plastice în civilizația islamică”, Kuala Lumpur

[10] Mehmet Ali Ekrem (1994), “Din istoria turcilor dobrogeni”, Ed. Kriterion, Bucuresti

[11] Prof. Univ. Dr. Nuredin Ibram (2007), “Musulmanii din Romania”, Ed. Golden

[12] COD DE PROIECTARE SEISMIC, Indicativ P 100-1/2013

[13] COD DE PROIECTARE PENTRU STRUCTURI DIN ZIDĂRIE, Indicativ CR 6

[14] WWW.WIKIPEDIA.ORG

_____________

Note: Suliman Sever - Ovidius University of Constanta Doctoral School of Applied Sciences, Constanta,

Romania, (e-mail: [email protected]) Professor PHD Eng. Gramescu Ana Maria - Ovidius University of Constanta, Constanta, Romania


DOI: 10.2478/ouacsce-2018-0012

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Introducing Environmental Technologies in

Industrial Fuel Combustion Processes

Marcel Ruscă, Tudor Andrei Rusu

_____________________________________________________________________

Abstract – Atmosphere pollution is a complex and worldwide process carried out

for a long period of time. Greenhouse effect, global warming and acid rain are only

some examples generated by atmospheric pollution. Experts discovered a strong

motivation on finding solutions for reducing pollutant emissions caused by

atmospheric pollution. Transport activities and fossil fuels combustion are the main

concern on environmental pollution, more than that, they are used in industrial

processes, being the main cause of environmental pollution.

We have to understand that global pollution is causing the main effect on economic

and social challenges of each country, a fact that will be hard to change in the future,

and every small step will help for a better and healthy environment. Sebes and Zlanta

city, from Alba regions, were the areas that draw our attention for studying the level of

atmospheric pollution for a period of 5 years. We made periodic determinations on

emission level for SO2, CO, CO2, NOx and writing down periodic reports. The

measurements were made in industrial areas for Zlatna and Sebes city and in urban

areas in Alba-Iulia city. Traffic environment was the main issue discovered after this

research. The concerning was on industrial pollution for the cities of Sebes and Zlatna.

The final part is offering solutions on reducing gaseous emissions in particular for

economic operators and for the industries as well. This research is particularly aimed at

emissions reduction like SO2, CO, CO2 and also for volatile organic compounds.

Directive 2008/50/CE concerning ambient air quality were the main sources where we

started on our research targeting on reducing atmospheric pollution.

Keywords – environmental technologies, industrial polluting emissions.

_____________________________________________________________________

1. ENVIRONMENTAL POLLUTION

In the last decade, researchers draw our attention in terms of environmental pollution,

especially on the atmosphere. The major impact is global warming caused by greenhouse

gas emissions. Scientists are offering information and alerts with conclusive evidence on air

pollution hoping to attract interest for those responsible.

Responsible organizations must understand that air pollution is affecting human

health in other to accelerate the attempts procedures for reducing environmental pollution.

Emission resulting from industrial processes must be measured for identification and

assessment. The assessment must be done for pollutant emissions with major impact on

surrounding environment for medium to long term. On this basis, we considered appropriate

a further research for seeking a solution aimed to slow down the negative impact of air

pollution on the planet.


Only the ones with financial strength and decision-making powers can implement a

development plan to reduce pollution. This can be done only with an appropriate innovation

study and a creative research. The overall conclusion is atmosphere pollution should be the

main concern for mankind and ensuring Directive 2008/50/CE concerning ambient air quality

is implemented worldwide.

2. ATMOSPHERE POLLUTION – MAIN CONCERNS

The sources of pollution are various, split between natural and human nature

factors. To appreciate each contribution is almost impossible. Sources of pollution can are

divided by different criteria. The common criteria divide them by the natural sources.

Through this principle, we have two alternatives: natural sources and anthropic ones.

Key air pollutants and their natural sources:

a) Soil contamination with virus and particulates caused by erosion;

b) Seawater caused by aerosol loaded with salts (Sulphur and Chlorides);

c) Plants with pollen, organic and inorganic substances;

d) Humans and animals in their physiological process discharging CO2, viruses;

e) Mass plants fire causing ash, Sulphur Oxides, Nitrogen and Carbon;

f) Volcanic eruptions through the hash, Carbon Oxides, Sulphur and Nitrogen;

g) Decomposition of organic, vegetable and animal matters;

h) Terrestrial or cosmic radioactivity;

i) Lightning;

j) Dust and sandstorms causing terrestrial particulates.

Fig.1 Distribution of pollutant source [1]

The sources used for human activities causing particulate matter evacuated into the

atmosphere are classified by their branch:

a) Food processing industry;

b) Road traffic;

c) Metallurgical industry;

d) Energy industry;

e) Chemical industry;

f) Oil industry.


In terms of procedural conditions, anthropogenic emissions are consisted by

particulate matter and gas emissions. COV, CO2, NOX, SOX, N2O and CO can be specified

for gas emissions and Lead, Cadmium, Chromium, Copper, Arsenic, Zinc and their

compound even non-metals for particulate matter and heavy metals powders.

Area pollution was the case study for us. Air pollution is identified in certain areas

well defined and distinguished at different distances from urban centers. In this case,

industrial activities and road traffic are the sources.

Fig.2 Atmospheric pollutants – sources [1]

If we are talking about anthropogenic sources, we have to exemplify combustion

process for heat supply and heating and the industrial processes for processing materials.

Vehicles are generating pollutant emissions close to the ground being concentrated at a low

level. In the same time, the level of pollutant emissions generated by vehicles may be

different according to the engine type, technical performances and last but not least by the

quantitative ratio fuel-air. Gas emissions resulting from automotive sector contains as main

pollutants: carbon monoxide (CO), nitrogen oxides (NOX) and unburnt hydrocarbons (HC).

Through a chemical process of oxidation and reduction, the pollutants may become clean

emissions. The overall conclusion is that artificial sources are the most numerous and

harmful emissions due to technological development and their generating process.

3. ASSESSING THE LEVEL OF AIR POLLUTION IN URBAN AREAS

Urban pollution factors are in direct relation with urban centre territorial size related

as well to: infrastructure, population density, industrial development and company’s location

through their manufacturing process are discharging particulate matter. The leading causes causing pollution in urban center are:

- The explosive sharp demographic increases together with massive migration from rural areas

to urban setting;

- Industrialisation not according to sustainable development policies;

- Dangerous increasing of road traffic;

- Missing green areas in places where pollution reaches its maximum.

Primary pollutants

CO CO2 NO2

SO2 NO NO

CH4 and other

hydrocarbons

SO3

HNO3 H2SO4

H2O2 O3 PAN

S

NO3 – and

SO42 - salts

Natural

sources

Static

Athropogenic

sources

Athropogen

ic sources Mobile


Industrial processes, road traffic and buildings heating process are causing

atmospheric pollution in urban agglomerations. Main chemicals found are Nitrogen,

Sulphur and Carbon.

3.1. Monitoring of air quality on Alba country

In the following table are presented separately air quality monitoring stations for Alba

country. They are part of National Network for Air Quality Monitoring (RNMCA).

Table 1. Pollutant elements and indicators [5]

Station codification

/Station Type Location Measured indicators

AB1

urban background

ALBA IULIA 7B

Lalelelor Street

SO2, NOX, CO, O3, PM10, Lead,

Cadmium, Nickel, Arsenic, COV

AB2

Industrial 1

SEBEŞ

M.Kogălniceanu Street

(4 Primary school)

SO2, NOX, CO, O3, PM10, COV

AB3

Industrial 1

ZLATNA

14 T.Vladimirescu Street

(Avram Iancu Industrial

High School)

SO2, NOX, CO, O3, PM10, Lead,

Cadmium, Nickel, Arsenic

Correlation between pollution sources and their level is done using meteorological

information from meteorological stations such as wind speed, pressure, temperature,

humidity and solar radiation intensity.

Nitrogen oxides as pollution factors derive from solid, liquid and gas fuel combustion,

several industrial installations, road traffic, commercial, institutional and residential areas

heating plans.

Table 2. Monitoring nitrogen oxides values from monitoring stations [5]

AB1 Station

Total data

Validated

hours

%

Available

data

Evidence with

concentration

200 µg/mc

%

Exceeding

frequency

Average

values µg

/mc

2013(year) 8010 91 0 0 21.31

2014(year) 6929 79 0 0 21.15

2015(year) 7716 88 0 0 21.41

2016(year) 8120 92.4 0 0 24.70

2017(year) 7872 89.6 0 0 23.81

AB2 Station

Total data

Validated

hours

%

Available data

Evidence with

concentration

200 µg/mc

%

Exceeding

frequency

Average

values µg

/mc

2013(year) No No 0 0 No

2014(year) No No 0 0 No

2015(year) 6197 78.9 0 0 18.68

2016(year) 7892 89.8 0 0 24.22

2017(year) 7335 83.73 0 0 27.66


AB3 Station

Total data

Validated

hours

%

Available data

Evidence with

concentration

200 µg/mc

%

Exceeding

frequency

Average

values µg

/mc

2013(year) 7427 84 0 0 19.97

2014(year) 6497 74 0 0 12.14

2015(year) 5709 65.1 0 0 10.47

2016(year) 8116 92.3 0 0 11.42

2017(year) 7698 87.8 0 0 18.40

Sulphur dioxide is a strong reagent gas, coming mostly from sulphurous fossil (coal,

fuel oil) used for fuel combustion. The fuel combustion is used for generating electrical and

thermal power due to industrial processes and the liquid fuel is used for engines internal

combustion for vehicles. Sulphur dioxide is the main element of acid rains.

Table 3 is offering information for Sulphur dioxide with values that not exceeded the

hourly limited value of 350 µg/m3. Data capture was found between a range of 91,8% for

AB1 Station and 55,6% for AB3 Station.

Table 3. Sulphur dioxide – Statistic data (average hourly values) [5]

AB1 Station

Total data

Validated

hours

%

Available

data

Evidence with

concentration

200 µg/mc

%

Exceeding

frequency

Average

values µg

/mc

2013(year) 8268 94.3 0 0 5.5

2014(year) 6913 78.9 0 0 5.1

2015(year) 8048 91.8 0 0 9.84

2016(year) 8096 92.1 0 0 7.89

2017(year) 8018 98.9 0 0 7.48

AB2 Station

Total data

Validated

hours

%

Available

data

Evidence with

concentration

200 µg/mc

%

Exceeding

frequency

Average

values µg

/mc

2013(year) 4435 50.6 0 0 7.2

2014(year) 7757 88.5 0 0 3.3

2015(year) 7910 90.2 0 0 6.76

2016(year) 7818 89.0 0 0 8.06

2017(year) 7829 96.4 0 0 8.81

AB3 Station

Total data

Validated

hours

%

Available

data

Evidence with

concentration

200 µg/mc

%

Exceeding

frequency

Average

values µg

/mc

2013(year) 0 0 0 0 0

2014(year) 0 0 0 0 0

2015(year) 4876 55.6 0 0 8.54

2016(year) 4698 76.2 0 0 3.28

2017(year) 4659 75.2 0 0 7.76


Particulate matter - PM 10 are pollutants in suspension, situated in the atmosphere.

They are transported on long distances by de wind or by the volcanic eruptions.

Furthermore, they arise from anthropogenic sources such as fuel combustion from the

energetic sector, production processes (metallurgical industry, chemical industry), building

sites, road traffic, waste dump industrial and municipal areas, district heating plants

especially the one using solid fuel. The minimum value accepted is 50 g/mc for a day.

Annually, the minimum accepted value is 40 μg / mc. Is not recommended to exceed more

than 35 times per year this value.

Table 4 Statistical data for PM10 [5]

AB1 Station

Total data

Validated

hours

%

Available

data

Evidence with

concentration

≥50 g/mc for a

day

%

Exceeding

frequency

Average

values µg

/mc

2013(year) 285 78 0 0 16.43

2014(year) 340 93.1 8 2.35 10.19

2015(year) 358 98 1 0.27 10.55

2016(year) 360 98.3 5 1.39 12.94

2017(year) 353 96.7 26 7.36 19.76

AB2 Station

Total data

Validated

hours

%

Available

data

Evidence with

concentration

≥50 g/mc for a

day

%

Exceeding

frequency

Average

values µg

/mc

2013(year) 210 57.5 2 0.95 13.19

2014(year) 344 94.2 10 2.91 16.34

2015(year) 357 97.8 5 1.37 14.60

2016(year) 363 99.1 2 0.55 12.39

2017(year) 331 90.68 16 4.83 14.39

AB3 Station

Total data

Validated

hours

%

Available

data

Evidence with

concentration

≥50 g/mc for a

day

%

Exceeding

frequency

Average

values µg

/mc

2013(year) 87 48 1 1.15 23.46

2014(year) 341 93.41 3 0.88 11.55

2015(year) 340 93.1 0 0 15.25

2016(year) 356 97.2 5 1.40 13.48

2017(year) 345 94.5 16 4.63 13.21

It can be seen from the statistical data presented that in 2015 the daily limit value of

50 μg / mc was exceeded once at the AB1 station and 5 times at the station AB2, compared

to the 35, in 2016 the daily limit value of 50 μg / mc was exceeded 5 times at AB1 station

and 2 times at AB2 station, and 5 times at station AB3 and in 2017 the daily limit value of

50 μg / mc was exceeded 26 times at AB1 station and 16 times at AB2 station, and 16 times

at AB3 station compared to 35 times admitted by Law no. 104/2011 - on ambient air

quality.


For heavy metals sampling considering different levels of toxicity, the limits are

different, for Lead annual limit value is 0,5 μg/mc. This value needs to be respected in the

immediate proximity of industrial sources.

The maximum value admitted for Arsenic is 6 μg/mc, Cadmium 5 μg/mc , and for

Nickel 20 μg/mc.

Annual average Lead (g/mc) Cadmium

(ng/mc) Nickel (ng/mc) Arsenic (ng/mc)

2014 AB1 0.008 0.090 3.464 0.693

AB3 0.015 0.082 2.684 0.606

Annual average Lead (g/mc) Cadmium

(ng/mc) Nickel (ng/mc) Arsenic (ng/mc)

2015 AB1 0.011 0.564 2.447 0.665

AB3 0.011 0.508 2.779 0.598

4. METHODS FOR REDUCING ATMOSPHERIC POLLUTION IN INDUSTRIAL AREAS

For reducing the level of pollutant emissions from the industrial environment we have

to start on reducing the pollutant from its origin. Since each industrial processes are specific

will study ways to reduce polluting emission, control the source in order to propose a

solution for retention or reducing the pollution.

By lowering air excess and flame temperature we decrease the number of nitrogen

oxides during the processes of combustion.

When implementing these measures is not applicable we need to impose selective

reduction. Due is catalytic and non-catalytic a chemical may be injected for releasing NH2

who attacks the molecules of NO and NO2.

As common reducing agents are used: ammonia, NH3, urea, CO(NH2)2, isocyanuric

acid, (HOCN)3.

These molecules are very reactive and paired with NO and NO2 molecules through

oxygen, are capable of reducing nitrogen oxide (NO) and nitrogen dioxide (NO2). In that

way, we are able to reach nitrogen gas (N2) and water vapors.

Sulphur dioxide retention is possible in all the phases of fuels usage. This is possible

before, during and after burning (through actions on waste gases).

The process of phasing-out Sulphur and Nitrogen has the effect of destruction for the

largest possible number of heavy molecules obtaining the increase ratio of light products.

Improving the retain ratio of sulphur to 65% is possible by introducing hydrogen in

all the stages of processing petroleum.

The action on desulphurization of gaseous fuel consists in extracting, concentrating

and retaining the hydrogen sulfide H2S, who through special processes will be treated.

Restricting the emission but only till 50% of the natural one is possible by enhancing

additives on the outbreak during combustion such as emulsions particles for hydrocarbons

or dolomite powder injected together with coal powder. Calcined limestone powder

injected in the outbreak (CaO) reacts with Sulphur dioxide resulting CaSO4.

The additives and desulphurization products that not reacted are collected into a

precipitator together with combustion air. This method has shown maximum efficiency due

to favorable temperature and sufficient pressure of injected limestone and air generated on

the upper part of the burner.


Volatile organic compounds are commonly used in industry due to their capacity of

evaporation after use.

By using volatile organic compounds appropriate precautions shall be taken due to the

risk concerned for surrounding environment on-air treatment where they are kept.

COV is defined as organic substances (excluding methane) containing carbon and

hydrogen who substituted partially or totally by other atoms in gaseous or vapor form in

normal technical conditions

5. CONCLUSIONS AND RECOMMENDATIONS

With these technical tools, we can come support reducing the level of pollutant

emissions from industry, we can establish adequate strategies for promoting environmental

protection then integrate them in industrial manufacturing and energy sector. Based on this

premise we are able to reduce the concentration of fine particles (PM2,5) up to 75%,

ground-level ozone (O3) up to 60%, risk to the natural environment caused by acidifying

and eutrophying till 2020, taking into account 2000 level as basis.

Directive 2008/50/CE on ambient air quality must be considered if we want to reduce

atmospheric pollution to minimize harmful effects on human and surrounding environment

health.

6. REFERENCES

[1] Ion Untea (2010), Air Pollution Control-Politehnica Press Publishing House Bucharest

[2] Virginia Ciobotariu, Ana Maria Socolescu (2008), Pollution and Environmental

Protection-Bucharest Economic Publishing House

[3] Daniela Ionela Ciolea (2012), Air Pollution-Universitas Petroşani Publishing House

[4] Florian Dan, Carmen Eva Dan (2002), Environment Pollution Fuels-Dacia Publishing

House Cluj Napoca- http://members.shaw.ca/james.case/lichens/biomonitoring.html;

[5] Environmental Protection Agency, Preliminary Report on Ambient Air Quality for

2015, 2016, 2017 in Alba County;

_____________

Note: Rusca Marcel - Cluj-Napoca Technical University of Cluj-Napoca, Faculty of Materials Science and

Environmental Engineering, 28 Memorandumului Street, 400114 Cluj-Napoca, Romania, (e-mail: [email protected]).

Rusu Tudor Andrei- Cluj-Napoca Technical University of Cluj-Napoca, Faculty of Materials Science and

Environmental Engineering, 28 Memorandumului Street, 400114 Cluj-Napoca, Romania


DOI: 10.2478/ouacsce-2018-0013

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

GIS Based Flood Flow Assessment in Small Catchments

for Flood Mapping in Bosnia and Herzegovina

Borislava Blagojević, Slaven Kovačević, Bojana Nedić, Nijaz Lukovac and Mirza Mujčić

_____________________________________________________________________

Abstract – An initial step in flood hazard mapping is hydrological modelling. We

present a recent river flood modelling approach in Bosnia and Herzegovina (BiH) for

small ungauged catchments of drainage area up to 32 km2. To estimate peak flow of

required probability in small catchments, we use the rational method. The paper focus

is GIS based procedure for producing the runoff coefficient map for BiH from the

DTM and land cover map. For validation of the peak flow modelling results in small

ungauged catchments we use diagrams of peak flow per catchment area (specific

runoff) versus catchment area in medium and large gauged catchments. The results

indicate agreement in specific runoff for 100 and 500 years return period compared to

reference runoff in gauged catchments and a mild drop in specific runoff for 20 years.

Keywords – rational method, runoff coefficient map, slope map, ungauged catchment

_____________________________________________________________________

1. INTRODUCTION

Flood hazard maps are important tools in the effort to protect human health, the

environment, cultural heritage and economic activity. Article 6 of the Floods Directive [1]

requires Member States to prepare flood hazard and flood risk maps (at the river basin

level) for the areas of potential significant flood risk identified under Article 5 or 13.1(a), or

for the areas for which Member States decided to prepare flood maps according to Article

13.1(b). Flood hazard maps show the geographical area which could be flooded under

different scenarios (Article 6.3) [1].

The on-going Project "Flood Hazard and Flood Risk Maps in Bosnia and

Herzegovina" (WB12-BIH-ENV-04C1) includes scenarios of fluvial (river) flood events

with return periods of 20, 100 and 500 years. There are 211 areas of potential significant

flood risk (APSFR) identified in the process of preliminary flood risk assessment. The

provision of input data on design peak flows for hydraulic modelling in river reaches

covering APSFRs, comprises hydrological modelling of 75 ungauged catchments

encompassing 146 ungauged sites. The drainage area of the ungauged catchments range

between about 1 km2 and 1499 km2, and therefore a range of methods are used to estimate

the design peak flows (Q20, Q100 and Q500). For the group of small ungauged catchments

with drainage area up to 32 km2 the rational method is applied.

The rational method has been proposed by the Irish engineer Thomas Mulvaney in

1851 and developed by the American scientist Kuichling in 1889. It is often referred to as

rational equation, because of the simplicity of its form. The peak discharge is obtained by

using the runoff coefficient of the area, rain intensity, and drainage area size.


The assumptions underlaying the rational method [2], are often strictly interpreted as

limitations for the application of the method. The assumption on nearly uniform runoff

occurrence from all parts of the watershed means that the runoff coefficient has to be nearly

the same over the entire drainage basin. Because this assumption is less likely to be valid as

the drainage basin size increases, the application of the method is interpreted as limited to

area as small as 0.8 km2 [3], although there are limits set to 15 km

2 [4] and 25 km

2 [5].

However, in [6] it is shown the rational method can be applied to much larger catchment

sizes than conventionally accepted.

Along with a question of rainfall intensity, the estimation of runoff coefficient is a

challenge in the rational method. There are variety of empirical indications provided for its

estimation, from the simplest ones that consider land use only, to functions linking the land

use, soil type and area slope [5].

In the paper we present GIS based procedure for obtaining the runoff coefficient map

for the whole territory of BiH. As input data we use the Digital Terrain Model (DTM) and

land cover map. We show the peak flow modelling results of rational method in small

ungauged catchments relative to the statistically modelled peak flows in medium and large

gauged catchments in BiH.

2. METHOD DESCRIPTION

The rational equation is the simplest method to determine peak flow from drainage

basin runoff:

Q = c i A (1)

where,

Q is peak discharge, m3/s

c is rational method runoff coefficient

i is rainfall intensity, m/s

A is drainage area, m2.

The equation (1) is dimensionally correct with SI units shown, while conversion

factors are applied when using usual units for i (mm/min or mm/hr) and A (km2 or ha).

The rainfall intensity i is typically found from Intensity/Duration/Frequency curves

for rainfall events in the geographical region of interest. We use the specified storm

frequencies of 20, 100 and 500 years, and the duration equivalent to the time of

concentration (Tc) of the drainage area. Instead of catchment decomposition, for each

catchment we use a composite Tc to obtain the design storm depth using the most

geographically representative of the adopted Depth/Duration/Frequency curves (Fig. 1-left)

and reduction factor curves (Fig. 2) applied to the daily precipitation of specified frequency

at the closest or most representative meteorological station (MS) to the ungauged catchment

(Fig.1-right). We calculate runoff with a constant rainfall intensity i in each catchment.

The rational method runoff coefficient (c) is a function of the land use, soil type and

drainage basin slope. We use the composite c for each ungauged catchment and before

returning it to the rational equation we apply runoff coefficient adjustment factor to account

for reduced infiltration during intense storms with high return periods. The composite c for

the catchment we find/calculate from the runoff coefficient raster map.


Fig. 1 Left - 6 Selected MS with DDF curves and associated ungauged catchments

Right - MS with daily design storms and associated ungauged catchments

Fig. 2 Storm reduction factor curves for 100-year return period at 6 meteorological stations.

The reduction factor shows rainfall depth ratio of less than 24 hrs. to daily precipitation

The procedure we used to create the runoff coefficient raster map for the whole

territory of BiH is shown in Fig. 3.

The procedure starts as two-tier process. First, we prepare the land cover data from

the Corine Land Cover database [8] with 14 land use classes; we reclassify it to 7 classes

according to the runoff coefficient table entries, and vectorize the data. After that, we start

the second-tier process by creating slope map from the available DTM data. Because the

slope class ranges do not conform our requirements, we reclassify the raster map to obtain

three slope classes (0-5, 5-15, >15%) corresponding to flat to rolling, rolling to hilly and

hilly to mountainous terrain respectively. We vectorize the map and insert 4 new fields in

the attribute table (Fig. 4). These fields are false Hydrologic Soil Group (A, B, C, D)

because we follow the procedure from HEC-GeoHMS [9] for producing CN (Curve

Number) raster map. Then, we calculate percentage of each class within the polygon.


Fig. 3 Procedure of creating raster runoff coefficient map

Vectorization

Reclassification

DATA

Land use DTM

Corine 2006 14 classes

DTM 20 m x 20 m

Land use 7 classes

Vectorization

Inserting new

fields in attribute table

Calculation of % in

field within polygon

Slope map

Slope map

UNIFYING land use and slope vector data UNION table

Reclassification

LOOKUP table

Runoff coefficient table for land

uses, slopes, and SCS soil types

HEC – GeoHMS Runoff coefficient Raster map


Fig. 4 Inserting 4 new fields (boxed) in the attribute table to store percentage of slope class

within polygon

Now, we have all the data we need to join two separate process tiers i.e. land use data

and slope data in the union table (Fig. 5).

Fig. 5 Union layer attribute table

The runoff coefficient table links land use and slope classes. Important step in the

process is creation of “Landuse” field in Union layer’s attribute table that corresponds to

“GRIDCODE” field. We proceed to creation of a lookup table in ArcGIS (Fig. 6).

Fig. 6 Lookup table

Here, we turn to HEC-GeoHMS to create runoff coefficient raster map by assigning

value to each raster grid cell assisted by Lookup table - overlapping the Slope layer and

Union layer. The final step is to generate a raster with “Generate CN Grid” tool found

under Utility tab of HEC Geo-HMS, for which we need DTM, Union layer and Lookup

table. The resulting runoff coefficient map is shown in Fig. 7.


Fig. 7 The runoff coefficient map of Bosnia and Herzegovina


The results of peak flow modelling by the rational method in our assignment can be

verified indirectly. There are a few gauging stations controlling small catchments in BiH.

Therefore, we have to use medium and large catchments for verification of results. We

visually compare the modelled peak flow per catchment area (specific runoff) in small

ungauged catchments to gauged catchments as a function of catchment area. The division

of the territory we select for comparison of specific runoff comprises three hydrogeologic -

karstic belts of the Dinaric Alps (Fig. 8), because karstic area presence is an influential

flood factor in BiH.

Fig. 8 Three karstic belts of the Dinaric Alps in Bosnia and Herzegovina [10]


The modelling results indicate a mild drop in specific runoff in both belts 2 and 3 for

20 years return period compared to reference runoff at gauging stations, and agreement for

100 and 500 years. Figure 9 shows example of specific runoff for 100 year flood in the belt

3 of the Dinaric Alps.

It is important to note the results from medium and large size gauged catchments are

based on statistical modeling of the 1961-1990 discharge series. The results we obtained in

ungauged catchments reflect more recent period when it comes to design storm base which

is the period until 2016, and land use situation considering CLC data from 2006-2012.

Fig. 9 100-year specific discharge from gauged catchments (x, +) and ungauged catchments

(•) in the Dinaric belt 3. The regression line constructed for gauged catchments is extended

in the plot only to show the fit in the range of small catchment area

4. CONCLUSION

GIS environment plays an important role in flood flow assessment, as shown in the

case of the runoff coefficient map development for the territory of BiH. The map then

improves river flood assessment procedure and decreases uncertainties in peak flow

estimation for small ungauged catchments. It facilitates all the hard work and valuable time

for determination of runoff coefficient that plays important role in the accuracy of flood

modelling results. By overlapping the runoff coefficient map as a raster layer format and

catchments as a vector (polygon) layer format, we can now easily determine runoff

coefficient for any catchment area in the country in only few steps.

5. ACKNOWLEDGEMENTS

The authors wish to thank Mr. Michael Jacobsen, the WB12-BIH-ENV-04C1 project

director, for providing the agreement from the contracting authority to submit this paper, as

well as Ms. Dalila Jabučar, the project team leader, for her suggestions on the paper

improvement. The project funding source is "EU IPA II Multi-Beneficiary Programme for


Albania, Bosnia and Herzegovina, the former Yugoslav Republic of Macedonia, Kosovo*,

Montenegro and Serbia". The Contracting Authority is the "European Investment Bank".

*This designation is without prejudice to positions on status, and is in line with

UNSCR 1244/199 and the ICJ opinion on the Kosovo declaration of independence.”

6. REFERENCES

[1] European Parliament and the Council of the European Union (2007), Directive

2007/60/EC of the European Parliament and of the Council of the European Union of 23

October 2007 on the assessment and management of flood risks [Online] available at:

https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32007L0060&from=EN

[2] V.P. Singh (1992), Elementary Hydrology, Prentice Hall, Englewood Cliffs, pag. 598

[3] Texas Department of Transportation (2016) Hydraulic Design Manual, pag. 4-48

[Online], available at http://onlinemanuals.txdot.gov/txdotmanuals/hyd/hyd.pdf

[4] HRU (1972), Design Flood Determination in South Africa. Report No. 1/72,

Hydrological Research Unit, Department of Civil Engineering, University of

Witwatersrand, RSA.

[5] OPW (2012), FSU, Urban and Small Catchment Flood Estimation, pag. 4 [Online],

available at http://opw.hydronet.com/data/files/FSU%20Work%20Package%204_2.pdf

[6] G.G.S. Pegram (2003), Rainfall, Rational formula and regional maximum flood - some

scaling links, Australian Journal of Water Resources, Vol. 7, nr. 1, pag. 29 - 39.

[7] EEA (2012) Corine Land Cover inventory

[8] – (2005) Hydrology - Appendix F – Rational method [Online] available at:

ftp://ftp.odot.state.or.us/techserv/Geo-

Environmental/Hydraulics/Hydraulics%20Manual/Chapter_07/Chapter_07_appendix_F/C

HAPTER_07_appendix_F.pdf

[9] US Army Corps of Engineers, Geospatial Hydrologic Modelling Extension HEC-

GeoHMS, [Online], available at: http://www.hec.usace.army.mil/software/hec-geohms/

[10] O. Bonacci (2015), Karst hydrogeology/hydrology of dinaric chain and isles, Environ

Earth Sci 74: 37. [Online], available at: https://doi.org/10.1007/s12665-014-3677-8

__________________

Note:

Blagojević Borislava – University of Niš, Faculty of Civil Engineering and Architecture, A. Medvedeva

nr. 14, 18000-Niš, Serbia (corresponding author phone: +381-65-8516535; e-mail: [email protected])

Kovačević Slaven –Hydraulic Engineering Institute Sarajevo, Stjepana Tomića nr. 1, 71000-Sarajevo,

Bosnia and Herzegovina (e-mail: [email protected]) Nedić Bojana – Hydraulic Engineering Institute Sarajevo, Stjepana Tomića nr. 1, 71000-Sarajevo, Bosnia

and Herzegovina (e-mail: [email protected])

Lukovac Nijaz – Hydraulic Engineering Institute Sarajevo, Stjepana Tomića nr. 1, 71000-Sarajevo, Bosnia and Herzegovina (e-mail: [email protected])

Mujčić Mirza – Hydraulic Engineering Institute Sarajevo, Stjepana Tomića nr. 1, 71000-Sarajevo, Bosnia

and Herzegovina (e-mail: [email protected])







DOI: 10.2478/ouacsce-2018-0014

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

Localized Irrigation System for Thuja Orientalis in

Intensive Culture

Mădălina Stănescu, Constantin Buta, Geanina Mihai and Lucica Roșu

_____________________________________________________________________

Abstract – In order to increase the competitiveness of an agricultural holding

through the efficient use of the production factors, the modernization of an

agricultural farm was carried out by exending the existing greenhouse with at least

700m2 for the intensive cultivation of ornamental plants - Thuja Orientalis. The

material is produced by initiating crops in pots, with seedlings grown in pots or

transplanting them in pots right after the first year of the multiplication and growing

them in containers, appropriate to their size, until reaching their full value. From a

technical point of view, reaching the objective will also be possible through a localized

irrigation system.

Keywords – containerized crops, greenhouse, localized/drip irrigation.

_____________________________________________________________________

1. GENERAL ASPECTS

The built-up area of 833.60 m2 of the greenhouse, covered by this paper, is located

within a private property farm in the town of Techirghiol, Constanta County (Fig.1).

Fig. 1 Layout of the surface to be arranged (Source: Google)

For the modernization of the agricultural farm by diversifying the activity it is

proposed to extend the existing greenhouse with a minimum of 700 m2 for the cultivation of

ornamental plants - thuja, in an intensive system.


The production of seedlings in containers involves initiating the crops in pots with

saplings obtained in pots or by transplanting them into pots immediately after the first year

from their multiplication and growing them in containers, appropriate to their size, until

harvest.

By growing in pots and containers throughout the entire time, these plants will have

an intact root system, well developed in a limited volume of substrate. Therefore, plants

that were grown in containers can be stored for a long time until they are sold, without loss.

Moreover, their cultivation in the final place can be realized in any season, almost all year

round.

Thuja orientalis (Thuja) is a medium sized Shrub that can reach up to 2-3 m in height,

with a piramidal crown and scaly leaves, joined in stems. The byological and ecological

requirements (moderate requirements regarding water, but requiring both soil and air

humidity, growth rate of approx. 50cm/year, crown easy to control through repeated

trimming) have placed the Thuja in the preferred category of plants used for the creation of

live courtains that protect from dust and wind.

From a technical point of view, the achievement of the specific objective can also be

possible by creating a local irrigation system with perforated ramps, with all the required

components and respectively, a water source, technological equipment, watering equipment

and equipment for the maintenance of the thuja crops.

The quality of the water used for crop irrigation must be analyzed from the design

phase, along with studies related to the resource and flow of water that can be provided.

The water-efficient watering method, with minimal losses, is the localized drip

irrigation that administers water individually, in each container at the level of the plant

parcel, ensures uniform water distribution and does not require high working pressures.

Fig. 2 Drip lines / perforated rapms for greenhouse irrigation

Applying watering during the growing period of the plants is done based on the

irrigation regime, which determines how many waterings are applied in a time period, what

quantity of water needs to be applied and when the watering should be applied. In principle,

watering is applied when the soil moisture drops down to the depth of the active layer (in

which the respective main plant mass develops) below the threshold known as "the

minimum humidity ceiling".

Strategies for reducing the water consumption in containerized crops also provide a

good crop organization, depending on the size of the containers, the type of substrate and

the water requirements of the plants.


2. THE CONSTRUCTION OF THE GREENHOUSE

The construction of the greenhouse has the height regime "Groundfloor", a maximum

height measured from the CTN level to the top of the roof of 5.10 m and the free height of

3.10 m, with:

- insulated foundations (inside the perimeter, of 0,40 m x 0,40 m) and continuous,

made of reinforced concrete (on the perimeter, reinforced concrete soles 0,40 m x 0,40 m

and a reinforced concrete beam of 0,30 m x 0,40 m);

- superstructure composed of metal posts made of INP200 profiles and metal beams

having upper and lower ends T-profiles and bracings made of 50 mm width metal strip.

- the wrapping is made out of 4mm glass and supported by the metal beams;

- the closures are made of lightweight materials (PVC film).

3. IRRIGATION SYSTEM

The built surface of the greenhouse is 833.60 m2, of which 784.89 m

2 is usable area

(40.88x19.20) and a net irrigable area of 720 m2.

- the irrigation water source is groundwater taken from a well drilled within the farm

and mechanically raised with a submersible pump. From the well, the water is discharged

into a PEHD underground pipeline, DN50 mm, PN 6, over a distance of about 99 m up to

the hydrant to which the mobile irrigation equipment is connected (Fig 3).

Fig.3 Hydrant for connecting the mobile equipment

- the pumping machinery is a submersible pump, WTX 2460-75 - made of stainless

steel, screw-type, triple-sealed, with the engine in a sump/ an oil pan/bath. The pump is

supplied with a command and control pannel that contains a startup capacitor, thermal

protection and a 15 m power cable (Fig. 4)

Fig. 4 Submersible pump, WTX 2460-75


- the equipment for irrigation distribution and application within the greenhouse

consists of - a physical assembly of distribution pipelines (CD) and watering pipelines (CU)

- perforated ramps.

The distribution pipelines (CD), having a role of taking the pressurized water from the

hydrant and distributing it to the watering pipelines, are made of high density polyethilene

tubes (PEHD), with a diameter of 40 mm, fitted with a coupling (either simple or with a

tap) for connecting the watering pipeline and with an isolation valve, connecting to the

transport pipelines (Fig. 5).

Fig.5 PEHD tube - PE80 D40 PN6 (left) and coupling detail (right and bottom)

The watering pipelines (CU)/ perofrated ramps are made of polypropilene tubes for

dripping irrigation, with incorporated nozzles, delivered in 100 m coils, with the following

technical specifications: 16 mm - dripping tube diameter; 30 cm - distance between the

dripping orifices; 4l/orifice/h - the dripping orifice flow; working pressure - 2,50 bar; 0,80

mm - the thickness of the tube (Fig. 6).

Fig. 6 Polypropilene tubes with incorporated nozzles: distance between dripping orifices

(top); dripping tube diameter (bottom left); dripping orifice flow (bottom right)

The equipment - is made of a overgound physical assembly of transport pipelines

(CT), distribution pilelines (CD) and perforated watering pipelines (CU) that serve an area

called “the watering station" (Fig. 7).


Fig. 7 Watering station

The area of a watering station (SPU) depends on the number of drippers working

simultaneously (np), thus the number of CU (NCu) that are working simultaneously,

established by the ratio between the capacity of the source (pump flow rate and working

pressure) and the flow rate of one dripper (qp), specific to the selected dripper.

The number of watering station (NPU) in the entire greenhouse will be given by the

ratio between the usable area of the greenhouse and the surface of a watering station and it

will be corelated with the watering periodicity (Fig. 8).

Fig. 8 Watering station arrangement diagram

The water supply scheme of the irrigation installations inside the greenhouse is

composed of:

- one central distribution pipeline (CD) placed along a central walkway with a width

of 1,00 m;

- the net area will be Snet=720 mp, divided into two equal areas, each of 9,00 m

width, on each side of the walkway;

a) The watering pipeline (CU) with the following properties:

- distance between the dripping orifices: dp=0,30 m;

- dripping tube diameter (mm): 16;

- dripping orifice flow rate: qp=4 l/h;

- length of the watering pipeline: LCU=9,00 m;

- number of dripping orifices in a watering pipeline:


np =LCU

dp=

9,00

0,30= 30p (1)

- flow rate of the watering (dripping) pipeline

QCU = np × qp = 30p × 4 lh⁄ = 120 l

h⁄ (2)

For the maximum flow rate of the pump, Qpump=1600 l/h and a lifting height

H=37.50 mCA,

- the number of watering pipelines (NCU) operating simultaneously is:

NCu =Qpompă

QCU=

1600 l/h

120l/h= 13.33CU (3)

NCu = 13CU sau NCu = 14CU (4)

- the total number of drippers in one watering station is:

npt/PU = np x NCU = 30 x13 = 390 p/PU (5)

npt/PU = np x NCU = 30 x14 = 420 p/PU (6)

b) The distribution pipeline (CD) with the diameter (mm) 40 and the distance dr=0,50m

between the couplings.

- length of the distribution pipeline while in operation:

LCD= NCU x dr = 13 x 0,50m = 6,50 m (7)

LCD= NCU x dr = 14 x 0,50m = 7,00 m (8)

c) The area of a watering station that administers the watering simultaneously:

SPU= LCD x LCU = 6,50 m x 9,00m = 58,50 mp (9)

SPU= LCD x LCU = 7,00 m x 9,00 m = 63,00 mp (10)

The total number of watering stations (NPU) for the entire greenhouse will be:

NPU =Snet

SPU=

720

63= 11.42 (11)

NPU = 12 watering station (12)

For the irrigation of the entire area of the greenhouse, 12 watering station can be

organized, 6 on each side of the walkway (Fig. 9).


Fig. 9 Waterig equipment layout

The total number of plants (pots) in a production cycle is:

Nplante = NPU x npt/PU = 4 x 420p/PU + 8 x 390p/PU =4800 plants (pots) (13)

Thuja pots diameters up to 25cm and 4 production cycles/year were considered.

The periodicity of watering depends on the water requirement of the plant – it is considered

that a watering is sufficient every 4÷5 days in the first year, and then a weekly watering.

The recommended period for applying the watering during the day is within the

interval / time frame 19 (evening) ÷ 10 (morning). Short and frequent waterings are not

recommended during hot periods because they favor the emergence of deseases.


4. CONCLUSION

Plant irrigation is an important work in any technology of producing planting material

and consequentlly for the containerized crops.

The advantages of containerized crops are both for the producer and for the buyer:

- plant production does not depend on the soil of the nursery/greenhouse;

- delivery is fast and anytime throughout the year;

- for storage, stratification stocking is eliminated

- plant growth is better since the root system is intact;

- planting can be done in any season.

Plants in containers have a substrate volume much smaller compared to their size,

which makes water to be rapidly consumed. Some substrates used in containerized crops

are sometimes very permeable and with little power to retain water. Also/Likewise, the

exposure of the recipients to the air currents and high temperatures requires careful

monitoring of the water in the substrate.

Thuja seedling growth depends greatly on ensuring the water requirement in the soil.

The localized irrigation sistem with perforated ramps transforms the continuous

current of water in drops, at low pressure, soaking the soil slowly, depending on the plant

requirement.

Due to the functional restrictions it implies (filtered water, low flow rate and low and

controlled pressure), the system is automated even from the design stage.

For watering in greenhouses, the automated system controls sequentially strictly the

water requirement of the plant, depending on the input values – temperature, humidity, PH,

luminosity etc., that leads to a minimum water and energy consumption and to an increased

efficiency of the technological process.

6. REFERENCES

[1] Mănescu A (1998), Alimentăricu apă, aplicații. Editura HGA, București, România

[2] Roșu L. (1999), Îmbunătățiri funciare. Editura Ovidius University Press, Constanța,

România

[3] Tuma J. (2010), Sisteme de irigare. Editura Casa, Oradea, România

[4] Iliescu Ana-Felicia (1998), Arboricultură ornamentală. Ed. Ceres, Bucureşti, România

[5] Mănescu Cristina (2010), Arboricultură ornamental, Facultatea de Horticultură,

USAMB Bucureşti, Bucureşti, România

[6] www.valrom.ro

__________________

Note:

Mădălina Stănescu - Ovidius University of Constanta, Bd. Mamaia nr. 124, 900356-Constanta, Romania

- S.C. SAM Proiect & Management S.R.L., Cumpăna, Romania

(corresponding author to provide phone: +40-241-619040; e-mail: [email protected]) Constantin Buta - Ovidius University of Constanta, Bd. Mamaia nr. 124, 900356-Constanta, Romania

Geanina Mihai - Ovidius University of Constanta, Bd. Mamaia nr. 124, 900356-Constanta, Romania

Lucica Roșu - Ovidius University of Constanta, Bd. Mamaia nr. 124, 900356-Constanta, Romania


DOI: 10.2478/ouacsce-2018-0015

______________________________________

ISSN 2392-6139 / ISSN-L 1584-5990

The Theoretical Foundation of the Concept of

"Architecture and the Built Environment Education"

Irina Cerasela Filip, Cosmin Filip

_____________________________________________________________________

Abstract – It is necessary to investigate, develop and promote architecture and

built environment education in order to increase the civic responsibility towards the

built environment and to create a functional, sustainable and aesthetic environment.

This type of education can and should lay the foundation for social responsibility

but for this, we need to make children and young people understand what being

responsible mean and that the city is the result of the involvement of all its

inhabitants.

Forming such citizens that are able to understand the idea that active

involvement and prospective thinking is the first step towards a sustainable

transformation of society is a complex and lasting process, which is why it has to start

from an early age.

Keywords – architecture and built environment education, education for

sustainable development, "new education" programs, traditional education system, “tree

of ideas” method

_____________________________________________________________________

1. INTRODUCTION

Architecture and built environment education is a complex field, which enriches the

general knowledge of students by aiming to familiarize them with key notions in order to

better understand the urban and rural environments in which they live, as well as increasing

the civic responsibility towards their communities.

In other words, it is necessary to prepare them for the various challenges of present

and future society, to contribute to their formation as responsible citizens who want to

understand, protect and rationally use the built and natural environment as promoters of

sustainable environmental development. [2]

If we take a glimpse of the built environment, one can say that it is necessary to

change the paradigm of the architectural and urban culture in Romania, and the first step is

to change the mentality, the vision of all the stakeholders of the architectural act, because

there is a need of a higher standard of quality in the built environment and, at the same

time, the protection of the existing architectural heritage. [4]

Changing this architectural paradigm can and needs to be done starting with the

education of children and young people, a change that has to be made in all forms of

education - formal, nonformal and informal - an important role being played by opinion

makers - parents, teachers, architects, civil engineers and so on. [3] [4]


The desire and motivation to research and promote this part of education starts from

the need to familiarize as many students as possible with concepts and issues related to the

built environment, given the imperative need to make younger generations aware that there

are realities which must be changed in our built environment and they are the ones who can

make these changes over time.

Another strong impetus for approaching this type of education among students was

their desire and curiosity to decipher the built environment in which they live in.

2. THE INTERPRETATION AND FRAMING OF THE CONCEPT OF

“ARCHITECTURE AND BUILT ENVIRONMENT EDUCATION”

Architecture and built environment education is not found within the traditional

education system, but we can include it in the field of the "new education" programs, which

are integrative, cumulative and correspond to various social and pedagogical needs. [7]

These programs are defined in the UNESCO programs, which have been adopted in

the last decades as a response of the educational systems to the imperatives of the

contemporary world in matter of political, economic, ecological, demographic, sanitary

issues etc. [7]

The specific content proposed from this perspective can be integrated at all levels,

fields and forms of education.

They are presented in terms of pedagogical objectives aimed towards: [7]

- environmental education;

- education for sustainable development;

- education for international understanding;

- peace and human rights education;

- education for participation and democracy (education for citizenship in a

democratic society/global citizenship education);

- education in the field of population;

- education for a new international order;

- education for communication and media;

- education for change and development;

- nutritional education;

- modern home education;

- leisure time education;

- intercultural education;

- civic education;

- economic education.

Related to the "new education", we can say that many of them contribute differently

to the foundation and development of the concept of architecture and built environment

education, along with the traditional education components: [7]

- intellectual education;

- aesthetic education;

- moral education;

- physical education;

- technological education;

- professional education;

- religious education.


This approach reflects the fact that architecture and built environment education is a

trans disciplinary field with links to traditional education as well as the "new education", a

connection through which several values can be promoted and complex notions can be

approached.

Fig. 1 The correlation between architecture and bult environment education and the other

components of education

Architecture and built environment education targets some of the themes and issues

from the types of education mentioned above, and through its versatility and variety of

approaches it can contribute substantially to developing the concept of education for

sustainable development.

It is necessary to highlight the link between these two types of education, architecture

and built environment education and education for sustainable development.

We could say that architecture and built environment education plays an important

role in the sustainable development of society, as the purpose of this education is to help

today's students understand tomorrow’s necessities in terms of sustainable development of

their society. [2] [4]

In other words, taking into consideration our field of activity, we can say that the

target of this type of education is to provide students with insight of the basic concepts and

phenomena that are related to the creation of a high-quality built environment, as well as

the protection of the existing architectural heritage.

The concept of sustainable development emerged at “The Earth Summit”, a United

Nations Conference on Environment and Development (UNCED), a conference held at Rio

de Janeiro, Brazil (3-14 June, 1992). [5]


On this occasion, environmental and development issues were brought to the

forefront, with a new development strategy, under the name of sustainable development.

This Summit was unprecedented for a UN conference, in terms of both its size and the

scope of its concerns. Twenty years after the first global environment conference, the UN

sought to help Governments rethink economic development and find ways to halt the

destruction of irreplaceable natural resources and pollution of the planet. [5]

The General Conference of the United Nations Educational, Scientific and Cultural

Organization (UNESCO), a meeting that took place in Paris in the autumn of 1997, passed

the Declaration on the Responsibilities of the Present Generations towards Future

Generations. The Declaration recognised that “the present generations have the

responsibility of ensuring that the needs and interests of present and future generations are

fully safeguarded”. It stressed the importance of making “every effort to ensure, with due

regard to human rights and fundamental freedoms, that future as well as present generations

enjoy full freedom of choice as to their political, economic and social systems and are able

to preserve their cultural and religious diversity”. And it stated that “the present generations

have the responsibility to bequeath to future generations an Earth which will not one day be

irreversibly damaged by human activity. Each generation inheriting the Earth temporarily

should take care to use natural resources reasonably and ensure that life is not prejudiced by

harmful modifications of the ecosystems and that scientific and technological progress in

all fields does not harm life on Earth”. [5]

The concept of sustainable development can be summed up in the triad of Economic

Prosperity-Social Equity-Environmental Protection, which is based on a balance between

these three components. This triad also influences the field of architecture and built

environment education, in which sustainability must become the key-word that influences,

directly and decisively, the built environment. Sustainability must become a way of life, a

way of thinking and acting.

This type of education develops and improves the capacity of individuals, groups,

communities, organizations and countries to think and act in favor of sustainable

development. It can generate a change in people's mentalities, potentiating their ability to

create a safer, healthier and more prosperous world, thus improving the quality of life.

Education for sustainable development offers a critical approach, increased awareness and

the power to explore and develop new concepts, visions, methods and tools. [7]

Therefore, architecture and built environment education aims to involve students in

activities with real applicability in the process of identifying, designing and solving

problems of the built environment, process in which they can express and engage their

personality, creativity, critical thinking and responsibility.

Such an example is the „Tree of ideas” method, a didactic/working method of

organizing and systematizing knowledge/ideas. In other words, it is a graphic concept in

which the statements/keywords are written on the drawing, both at the bottom of the tree

(roots) and at the top (branches of the fruit tree).

In our case, the roots of the tree are the sources that “feed” the architecture and built

environment education and represent the fields underlying this side of education that

contribute to changing the individual and collective behaviors of children and young people

to create a functionally, durably and aesthetically built environment, which is in harmony

with the natural environment and satisfies people’s needs and aspirations.

The trunk of the tree represents the architecture and built environment education, the

main, strong, long-lasting element, which is nurtured by the roots.

The branches have fruits, let’s call them “the books of knowledge”, which are part of

the objectives/directions/principles of sustainable development of society.


Fig. 2 The transdisciplinary dimension of the architecture and built environment education

and its applicability in various fields


The importance of architecture and built environment education lies in its ability to

help students understand the complex processes that transform the environment in which

they live - the activities of modeling and remodeling their surroundings.

Each book in the tree represents a very important theme that can be approached

through different interactive and interesting activities. Based on these various activities that

can be carried out within this trans disciplinary process of architecture and built

environment education, students will develop different skills, including:

- ability to self-manage the learning process;

- learning by doing, design thinking and participatory design (co-design);

- social responsibility, critical thinking (the ability to critically and constructively

analyze the built environment in which they live);

- various ways of expressing and presenting a project;


- research, planning, decision-making and problem-solving skills;

- social skills, collaboration, communication and teamwork;

- awareness and cultural expression skills;

- creativity and imagination, spatial perception and visual literacy.

4. CONCLUSION

The general purpose of this type of education is to help students understand the

complex processes that transform the environment in which they live.

The architecture and built environment education is a long and continuous process,

and educating students in this spirit requires a good training for those involved in this

process: teachers, architects, civil engineers, urban planners etc.

For this reason, setting the theoretical foundation of this concept and establishing its

strategy and main educational objectives that can lead to the development of individual and

collective skills, attitudes and knowledge in this field represents a constant challenge for all

those involved in the education process.

6. REFERENCES

[1] Alpopi C. (2007), Principiile Dezvoltării Durabile, Cercetări practice și teoretice în

Managementul Urban, anul 2, nr. 3, ASE Bucharest

[2] European Association for Architectural Education (2005) Diversity: A Resource for the

Architectural Education, „Ion Mincu” University Press, Bucharest

[3] O.A.R. (2010), Politica pentru arhitectură în România 2010-2015. Cultura mediului

construit și calitatea vieții, Publication of the Order of Architects in Romania

[4] arh. Sava M et. al. (2016) De-a arhitectura. Educație pentru arhitectură și mediu

construit. Curriculum opțional pentru clasa a III-a si a IV-a, Ghidul cursului De-a

arhitectura, Editura Universitară „Ion Mincu”, Bucharest, second edition revised and added

[5] Sustainable Environment [Online], available at: http://www.sustainable-

environment.org.uk/Principles/Future_Generations.php

[6] UN Sustainable Development Goals, Goal 11: Sustainable cities and communities,

[Online] available at: https://www.un.org/sustainabledevelopment/cities/

[7] UNESCO Education Center (2018), Progress on education for sustainable development

and global citizenship education, [Online], available at:

https://unesdoc.unesco.org/ark:/48223/pf0000266176

__________________

Note:

Filip Irina Cerasela - National College of Arts "Queen Mary" Constanta, Bd. Alexandru Lapusneanu nr.

11, 900178, Constanta, Romania (phone: +40 724 744492; e-mail: [email protected]) Filip Cosmin - Ovidius University of Constanta, Bd. Mamaia nr. 124, 900356-Constanta, Romania (e-mail:

[email protected])

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