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1 A novel computational method to nonlinear reaction-diffusion system using shifted Legendre polynomials M.Mahalakshmi ,R.Seethalakshmi G.Hariharan Department of Mathematics, School of Humanities & Sciences, SASTRA Deemed University, India Abstract The mathematical model of Praveen et al. (Biochemical Engineering Journal, 91 (2014):129-39) in immobilized enzymes is discussed. In this paper, an efficient shifted Legendre computational matrix method (LCMM) is applied for solving the nonlinear differential equations with Michaelis-Menten kinetics. To the best our knowledge, until there is no rigorous Legendre operational matrix based solutions has been reported for the above model. Theoretical results are obtained to analyze the effect of different parameter values. Several examples are given to demonstrate the validity and applicability of the proposed spectral method. The numerical results are compared with MADM results. Satisfactory agreement with the ADM results is noticed. Keywords: Mathematical modeling; immobilized enzymes; Legendre operation matrices; Adomian decomposition method; steady state conditions. 1. Introduction In recent years, many orthogonal functions and polynomials have been implemented to obtain the quality solutions of differential equations[1]. The reaction-diffusion model has been developed in the spherical catalyst particles for Michaelis-Menten type kinetics and the steady state equation to determine the concentration profiles of substrate inside catalyst particles to assess the design and performance of such reactors [2]. Mohammadi and Hosseini[3] used a new Legendre wavelet approach for solving the singular ordinary differential equation [3]. Khellat and Yousefi [4] derived the linear Legendre mother wavelets matrices of integration. In recent years, wavelets have found their place in many applications such as image processing, signal processing and solving differential and integral equations. Yousefi [5] applied the Legendre wavelets method (LWM) for solving the differential equations of Lane Emder type. Razzaghi and Yousefi [6, 7] had used the Legendre wavelets for constrained optimal control problems and variational problems. Recently, Hariharan [8] used an efficient Legendre wavelet based approximation method for a few-Newell and Allen-Cahn equations. Hariharan and Kannan [9] reviewed the wavelet solutions for the solutions of reaction-diffusion equations arising in science and engineering. Excellent references there in [9]. Jafari et al. [10] solved fractional differential equations by using Legendre wavelets in collocation method. Praveen et al.[11] have studied the theoretical analysis of intrinsic reaction kinetics and the behavior of immbolized enzymes International Journal of Pure and Applied Mathematics Volume 119 No. 15 2018, 387-403 ISSN: 1314-3395 (on-line version) url: http://www.acadpubl.eu/hub/ Special Issue http://www.acadpubl.eu/hub/ 387

Transcript of A novel computational method to n onlinear reaction ... · A novel computational method to n...

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    A novel computational method to nonlinear reaction-diffusion system using

    shifted Legendre polynomials

    M.Mahalakshmi ,R.Seethalakshmi G.Hariharan

    Department of Mathematics, School of Humanities & Sciences,

    SASTRA Deemed University, India

    Abstract

    The mathematical model of Praveen et al. (Biochemical Engineering Journal, 91

    (2014):129-39) in immobilized enzymes is discussed. In this paper, an efficient shifted Legendre

    computational matrix method (LCMM) is applied for solving the nonlinear differential equations

    with Michaelis-Menten kinetics. To the best our knowledge, until there is no rigorous Legendre

    operational matrix based solutions has been reported for the above model. Theoretical results are

    obtained to analyze the effect of different parameter values. Several examples are given to

    demonstrate the validity and applicability of the proposed spectral method. The numerical results

    are compared with MADM results. Satisfactory agreement with the ADM results is noticed.

    Keywords: Mathematical modeling; immobilized enzymes; Legendre operation matrices;

    Adomian decomposition method; steady state conditions.

    1. Introduction

    In recent years, many orthogonal functions and polynomials have been implemented to

    obtain the quality solutions of differential equations[1]. The reaction-diffusion model has been

    developed in the spherical catalyst particles for Michaelis-Menten type kinetics and the steady

    state equation to determine the concentration profiles of substrate inside catalyst particles to

    assess the design and performance of such reactors [2]. Mohammadi and Hosseini[3] used a new

    Legendre wavelet approach for solving the singular ordinary differential equation [3]. Khellat

    and Yousefi [4] derived the linear Legendre mother wavelets matrices of integration. In recent

    years, wavelets have found their place in many applications such as image processing, signal

    processing and solving differential and integral equations. Yousefi [5] applied the Legendre

    wavelets method (LWM) for solving the differential equations of Lane – Emder type. Razzaghi

    and Yousefi [6, 7] had used the Legendre wavelets for constrained optimal control problems and

    variational problems. Recently, Hariharan [8] used an efficient Legendre wavelet based

    approximation method for a few-Newell and Allen-Cahn equations. Hariharan and Kannan [9]

    reviewed the wavelet solutions for the solutions of reaction-diffusion equations arising in science

    and engineering. Excellent references there in [9]. Jafari et al. [10] solved fractional differential

    equations by using Legendre wavelets in collocation method. Praveen et al.[11] have studied

    the theoretical analysis of intrinsic reaction kinetics and the behavior of immbolized enzymes

    International Journal of Pure and Applied MathematicsVolume 119 No. 15 2018, 387-403ISSN: 1314-3395 (on-line version)url: http://www.acadpubl.eu/hub/Special Issue http://www.acadpubl.eu/hub/

    387

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    system for steady state conditions. Zaser Aghazadeh et al.[12] developed the Legendre wavelet

    method for solving singular Intergo-differential equations. Recently, Zhijun et al. [13] used

    Legendre wavelet method for solving fractional integro-differential equations. Fukang Yin et at.

    [14] presented the Spectral methods using Legendre wavelets for nonlinear Kelin/sine Gordon

    equations. Fukang Yin et al.[15] established a coupled method of Laplace transforms and

    Legendre wavelets for nonlinear Klein-Gordon equations. Masood Roodaki et al.[16] applied

    two dimensional Legendre wavelets and their Applications to integral equations. Sahu et al.[17]

    studied the Legendre wavelet operational method for the numerical solutions of nonlinear

    Volterra integro-differential equations system.

    In this paper, we have applied Legendre Computational Matrix Method for solving

    differential equations with Michaelis-Menten kinetics.

    The organization of this paper as follows: In section 2, some relevant properties of shifted

    Legendre polynomials are presented. In section 3, Mathematical model of the Michaelis-Menten

    kinetics is discussed. Method of solution by the Legendre computational matrix method

    presented in section 4. Illustrative examples are given in section 5. Results and discussions are

    given in section 6. Concluding remarks are given in section 7.

    2. Some properties of the shifted Legendre polynomials [1]

    The well known Legendre polynomials Pn(z), defined on the interval [-1,1], have the

    following properties:

    Pn(z) = (-1)n Pn(z), Pn(-1) = (-1)

    n, Pn(1) = 1 (1)

    It is well known that the weight function is ω (z) =1 and the weighted space )1,1(2 L is

    equipped with the following inner product and norm;

    2

    11

    1

    ),(,)()()(),( uuudzzzvzuvu

    . (2)

    The set of Legendre polynomials forms a complete orthogonal system )1,1(2 L and;

    ,12

    2)(

    2

    nhzP nn (3)

    is obtained. In order to use these polynomials on the interval [0, L] the so-called shifted

    Legendre polynomials are defined by introducing the change of variable z = .12

    L

    x

    The shifted Legendre polynomials are defined as;

    ()(*

    nn PxP )12

    L

    xwhere ,)1()0(

    * n

    nP (4)

    The analytic form of the shifted Legendre polynomial )(*

    xPn of degree n is given by;

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    n

    k

    k

    k

    kn

    n xLkkn

    knxP

    02

    *

    )!()!(

    )!()1()( . (5)

    Let ,1)( xL and the weighted space ),0(2 LL

    Lis defined with the following inner product and

    norm;

    .,,)()()(, 21

    0

    LLLuuudxxxvxuvu L

    L

    (6)

    The set of the shifted Legendre polynomials forms a complete ),0(2 LLL

    orthogonal system and

    122)(

    2*

    n

    Lh

    LxP nn

    L is obtained. The function u(x) which is square integrable in [0,L], may

    be expressed in terms of shifted Legendre polynomials as;

    0

    * ),()(i

    ii xPcxu (7)

    where the coefficients ic are given by;

    ,.....2,1,0,)()()()(

    1

    0

    *

    2*

    idxxxPxuxP

    c L

    L

    i

    i

    i

    L

    (8)

    2.1 Fundamental relations

    It is suggested the solution LCxu m ,0)( can be approximated in terms of the first (m+1) terms of shifted Legendre polynomials given by

    m

    i

    ii xPcxu0

    * ).()( (9)

    3. Formulation of the problem and analysis [11]

    The mass balance differential equation for substrate and product are

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    )11(02

    )10(02

    2

    2

    2

    2

    Vdr

    dp

    rdr

    pdD

    Vdr

    ds

    rdr

    sdD

    p

    s

    where s and p are the concentration of substrate and product. Here sD and pD is the diffusion

    coefficient for substrate and product within the support. The enzymatic reaction rate V for

    various kinetic mechanisms is given as follows

    (i) Simple Michaelis-Menten

    sK

    sVV

    s

    m

    (12)

    (ii) Uncompetitive substrate inhibition

    sI

    m

    KKss

    sVV

    )/1( (13)

    (iii)Total competitive product inhibition

    sIs

    m

    KKpK

    sVV

    )/1( (14)

    (iv) Total non- competitive product inhibition

    V))(/1( sKKp

    sV

    sIs

    m

    (15)

    (v) Reversible Michaelis - Menten reaction

    )(

    )('

    es

    em

    ssK

    ssVV

    (16)

    where sK - Intrinsic half saturation constant.

    IK - Intrinsic inhibition constant.

    mV - Maximum reaction rate

    mV ' - Maximum reaction rate for reversible reaction.

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    es - Equilibrium substrate concentration (reversible reaction)

    Using the following dimensionless variables

    II

    s

    Iss K

    p

    K

    K

    U

    Rt

    K

    p

    K

    s

    K

    s 00

    0

    0 ,,,,,

    2

    1

    2

    1

    33

    sp

    m

    p

    ss

    m

    sKD

    VU

    KD

    VU (17)

    Eq.(10) can be written in dimensionless form for simple Michaelis-Menten kinetics,

    uncompetitive substrate inhibition, reversible Michaelis-Menten reaction [12]

    )(92 2

    2

    2

    fdx

    d

    xdx

    ds (18)

    where the nonlinear reaction term )(f representse

    e

    1,

    )1)1(,

    1 for

    simple Michaelis- Menten, uncompetitive substrate inhibition and reversible Michaelis-Menten

    reaction respectively.

    e - dimensionless equilibrium substrate concentration for reversible reaction.

    For total competitive and non-competitive product inhibition systems the mass balance Eq.(10 )

    and

    Eq. (11) becomes

    ;),(92 2

    2

    2

    fdx

    d

    xdx

    ds ),(9

    2 22

    2

    fdx

    d

    xdx

    dp (19)

    where ),( f represents )1)(1(

    ,1

    for total competitive and non-

    competitive product inhibition respectively.

    The boundary conditions for Eq. (9) and (10) are

    1,

    ,00

    00

    xwhen

    xwhendx

    d

    dx

    d

    (20)

    where

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    -Dimensionless substrate concentration.

    0 - Dimensionless substrate concentration in the catalyst surface and outside the support.

    - Dimensionless product concentration.

    0 - Dimensionless product concentration outside the support.

    x - Dimensionless radial distance.

    - Ration of intrinsic half saturation constant over intrinsic inhibition constant.

    s - Thiele modulus for substrate

    p - Thiele modulus for product.

    3.1 First order catalytic kinetics

    We consider the situation where the dimensionless substrate concentration is less than 1.

    Hence Eq. (18) reduces to

    92 2

    2

    2

    sdx

    d

    xdx

    d (21)

    3.2 Zero order catalytic kinetics

    We consider the second major limiting situation found in practice, when the dimensionless

    substrate concentration is very much greater than 1. Eq.(18) reduces to the simple linear

    equation

    2

    2

    2

    92

    sdx

    d

    xdx

    d

    (22)

    4. Method of Solution

    Consider the Eq.(21)

    )(9)(2

    )(22 xxD

    xxD s (23)

    with the initial conditions 0)0(',)1( 0

    The proposed method is applied with m = 2 and the solution )(x is approximated as follows;

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    )()(*

    2

    0

    xPcx ii

    i

    (24)

    For m = 2, a system of linear equations is obtained, two of them from the initial conditions and

    other from the main equation using the collocation point x =0.5 which is the root of )(*

    xPi = 0

    Eq.(24) can be written in the following matrix form;

    AxPx )()(

    where )()()()( *2*1*0 xPxPxPxP , A Tccc 210

    Here 166)(,12)(,1)( 2*

    2

    *

    1

    *

    0 xxxPxxPxP

    5. Illustrative Examples:

    Limiting Cases

    Case: (i)

    Consider s =1, 0 =100 in Eq.(23)

    The matrix equation for this problem is;

    FAPPDx

    PD )2

    ( 2 (25)

    where 5.001P ,

    000

    000

    12002D

    000

    600

    020

    D

    The main matrices for the initial conditions are

    0)0(,100)1( DAPAP (26)

    From the Eq. (25) and (26), we get 76.1128.3596.52 210 ccc

    Using the aforesaid Legendre spectral method, one can obtain

    44.2956.70)( 2 xx

    Case: (ii)

    Consider s = 0.1, 0 =10

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    The matrix equation for this problem is;

    FAPPDx

    PD )2

    ( 2 (27)

    The initial conditions are

    0)0(,10)1( DAPAP (28)

    From the Eq. (27) – (28) we get 025.0075.09.9 210 ccc

    Using the aforesaid Legendre spectral method, one can obtain

    85.915.0)( 2 xx

    Case:(iii)

    Consider s =0.3, 0 =10

    The matrix equation for this problem is;

    FAPPDx

    PD )2

    ( 2 (29)

    The initial conditions are

    0)0(,10)1( DAPAP (30)

    From the Eq. (29) – (30) we get 184.9612.0204.0 210 ccc

    Using the aforesaid Legendre spectral method, one can obtain

    776.8224.1)( 2 xx

    Case. (iv) Consider the equation (22)

    22 9)(

    2)( sxD

    xxD (31)

    with the initial conditions 0)0(',)1( 0 .

    Limiting Cases

    Case: (i)

    Consider s =1, 0 =100

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    The matrix equation for this problem is;

    FAPDx

    PD )2

    ( 2 (32)

    The initial conditions are

    0)0(,100)1( DAPAP (33)

    From the Eq. (32) – (33) we get 25.075.099 210 ccc

    Using the aforesaid Legendre spectral method, one can obtain

    5.985.1)( 2 xx

    Case:(ii)

    Consider s =0.1, 0 =10

    The matrix equation for this problem is;

    FAPDx

    PD )2

    ( 2 (34)

    The initial conditions are

    0)0(,10)1( DAPAP (35)

    From the Eq. (34) – (35) we get 0025.00075.099.9 210 ccc

    Using the aforesaid Legendre spectral method, one can obtain

    985.9015.0)( 2 xx

    Case:( iii)

    Consider s =0.3, 0 =10

    The matrix equation for this problem is;

    FAPDx

    PD )2

    ( 2 (36)

    The initial conditions are

    0)0(,10)1( DAPAP (37)

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    From the Eq. (36) – (37) we get 028.0084.0888.9 210 ccc

    Table: 1 Comparison of dimensionless substrate concentration (Zero and First order reaction)for s =0.1 and 0 = 1

    0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 19.84

    9.86

    9.88

    9.9

    9.92

    9.94

    9.96

    9.98

    10

    10.02

    MADM

    LCMM

    Eq.21

    LCMM

    Eq.22

    x

    MADM LWM

    (Eq.21)

    LWM

    (Eq.22)

    0

    9.9900 9.9901 9.9850

    0.2

    9.9906 9.9905 9.9856

    0.4

    9.9922 9.9920 9.9874

    0.6

    9.9951 9.9940 9.9941

    0.8

    9.9989 9.9946 9.9946

    1

    10.004 10.000 10.000

    100

    1.0

    s

    X

    X

    )(x

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    Fig1. Comparion between the MADM and LCMM for s and 0

    Table: 2 Comparison of dimensionless substrate concentration (Zero and First order

    reaction) for s =0.3 and 0 = 10

    0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 18.5

    9

    9.5

    10

    MADMLCMM

    Eq.22

    LCMM

    Eq.21

    Fig2. Comparion between the

    and LCMM for s and 0 MADM

    Table: 3 Comparison of dimensionless

    substrate concentration (Zero and First

    X

    MADM LCMM

    (Eq2.2)

    0

    9.8700 9.8702

    0.2

    9.8749 9.8747

    0.4

    9.8896 9.8994

    0.6

    9.9147 9.9145

    0.8

    9.9483 9.9438

    1

    9.9927 10.000

    100

    3.0

    s

    X

    )(x

    x

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    order reaction) for s =1and 0 = 100

    0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 198.5

    99

    99.5

    100

    MADM

    LCMM

    Eq.22

    Fig3. Comparion between the MADM and LCMM for s and 0

    X MADM

    LCMM

    (Eq.22)

    0

    98.500 98.500

    0.2

    98.574 98.560

    0.4

    98.7525 98.740

    0.6

    99.0495 99.040

    0.8

    99.465 99.460

    1

    100.00 100.000

    100,10 s

    )(x

    x

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    6. Results and Discussion

    The numerical simulation of dimensionless concentration )(x for various values of

    parameters 0

    , ands

    are given in figures (1-3). Tables ( 1-3) show the comparison between

    the proposed LCMM results and the modified Adomian decomposition method (MADM) for

    various values0

    ands

    .Our results have been compared with MADM results[11]. For larger

    M, we get the results closer to the analytical solution.

    7. Conclusion

    We have applied a new Legendre spectral algorithm combined with the associated

    operational matrices of derivatives. This proposed algorithm was employed for solving nonlinear

    differential equations model with Michaelis-Menten enzyme kinetics. According to the

    numerical simulations, it has been concluded that the proposed spectral method may be extended

    to solve other types of linear and nonlinear enzyme kinetics models.

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