ABSTRACT OF ARTICLES VOL 10, JOURNAL OF NIGERIAN ASSOCIATION OF MATHEMATICAL PHYISCS, (2006)

  1. Neutrino mass

2.      New One-Boson-Exchange Potential functions

 

  1. Contribution of oblateness of the sun to radar sounding according to Newtonian mechanics
  1. Theoretical model analysis of molecular orientations in liquid protein dielectrics

  1. Optmizied random phase approximation for the phase diagram of C60  material

6.      The F-Region Equatorial Ionospheric Electrodynamics Drifts

7.      On temperature control of buildings by adobe wall design: Duffin and Knowles’ exponential transmission line model revisited

8.      First order normalization in the perturbed restricted three–body problem with variable mass

  1. A 2-dimensional finite element simulation of cooling in castings

  1. Analysis of Stokes waves theory as a diffusion problem

  2. Remarks on thermal explosions in the early evolution of the earth.

  3. An investigation of groundwater condition in Agbede by Geelectrical resistivity method.

13.The application of geophysics in environmental impact assessment: A case study in Jeddo, Delta State, Nigeria

  1. Characterization of formations and groundwater potential of Amai and Obiaruku in Delta State using resistivity and seismic refraction measurements

  2. Variable order one-step methods for initial value problems I

  3. An application of the maximal independent set algorithm to course allocation

  4. The turning points in the solution of n-queens problem using backtracking method

  5. Software package for analysis of completely randomized block design

  6. Three algorithms for Egyptian fractions

  7. Measure synchronization in a coupled Hamiltonian associated with the motion of particles in a periodic potential

  8. Active control versus recursive backstepping control of a chaotic system

  9. Synchronization of Forced damped Pendulum via Active Control

23. Some thermodynamic non-Fermi liquid properties of correlated electron systems.

24. Plasma heating by non-linear wave-Plasma interaction

  1. On finitely many fixed points

26.Some remarks on certain Bazilevic functions

  1. On the successive coefficients of certain Univalent functions

  2. On a differential subordination of some certain subclass of Univalent function

29. On the dynamic Stability of a quadratic-cubic elastic model structure pressurized by a slowly varying load

30. Asymptotic solution on the dynamic buckling of a column stressed by a dynamically slowly varying load

31. Dynamic analysis of a Bernoulli-Euler beam via the Laplace transformation technique

  1. The period of relaxation oscillations of a nonlinear system using singular perturbation methods

  2. On the steady state temperature profiles of biological tissues during microwave heating.

  3. Self-similar solution for coupled thermal electromagnetic model during microwave heating of biological tissues.

35. Impact of electric and magnetic fields in a resistant medium on the velocity of a particle subject to varying path angles

36. Vorticity determination in a hydraulic jump by application of method of characteristics

  1. Hydrodynamic dispersion of a reactive solute in Electro-Osmotic flow using quadratic polynomials

38.Existence of a secondary flow for a temperature dependent viscous couette flow.

  1. A Continuous formulation of some classical initial value volvers by non-Perturbed multistep collocation approach using Chebyshev polynomials as basis functions

40. Fairing NURBS curve by dual parameter optimization

41. Perturbed segmented domain collocation Tau-method for the numerical solution of Second Order Boundary Value problems

  1. Viscous dissipation effects on the flow of a radiating gas between concentric elliptic cylinders

  2. Radiation effect of magnetohydrodynamic flow of gas between concentric spheres

44. Perturbation analysis on the dynamic buckling of a lightly damped spherical cap modulated by a slowly varying sinusoidal load (1)

45. On the dynamic buckling of lightly damped cylindrical shells modulated by a periodic load

  1. One Leg hybrid P-stable substitution LMM for oscilatory IVPs in ODEs.

  2. Hessian Spectrum to perturbation factor for gradient method algorithm

  3. Jacobian approach to optimal determination of perturbation parameter for gradient method

  4. Control approach to Queue Theory

50.A family of block methods for special second order initial value problems [I.V.Ps].

51.Numerical integrators for Stiff and Stiff oscillatory First Order initial value problems

  1. Periodic solutions of periodic differential equations

  2. A generalised interpolating post–processing method for integral equation

  3. On the existence and uniqueness result for a two-step reactive-diffusive equation with variable pre-exponential factor

  4. On a Subclass of analytic functions

  5. Heuristic framework for parallel sorting computations

57. A software for the RSA Encription

  1. Quantum computer gate simulations

  2. Effective utilization of weighting adjustment for the estimates of means in survey non-response

60.Effect of queue discipline on the performance of a queueing system

  1. A mathematical model for Lassa fever

62. Mathematical model for bird flu disease transmission

63. The effect of stochastic migration on an HIV/AIDS transmission model.

64.Qualitative study of Kermack and Mckendrick’s epidemic model

  1. Mathematical models to simulate the East African trypanosomiasis population dynamics.

66. Thermal neutron counts and derivated charts

67. On the fluctuating filtrate

  1. A new poof of multiple solutions of combustions problems

  2. On the possibility of multiplicity of temperature fields in a microwave heating cancer therapy

  3. Unsteady Magneto-Hydrodynamic (MHD) flow of a uniformly stretched vertical permeable surface I in the presence of heat generation/absorption and a first order chemical reaction.

  4. Biomechanics of the brain; some remarks on Biot’s equations of consolidation theory with deformation-dependent permeability

  5. Relative null controllability of linear systems with multiple delays in state and control

  6. Relative controllability of nonlinear systems with multiple delays in state and control

  7. Criteria for exponential asymptotic stability in the large of perturbations of linear systems with unbounded delays.

  8. On the convergence profile of a discretized scheme for a two-dimensional constrained optimal control problem

  9. Relative controllability of nonlinear neutral Volterra Integrodiferential systems with delays in control

77. Stability of discrete control systems

78.Necessity and sufficiency conditions for the absolute null controllability for Linear delay perturbations

79. Euclidean null controllability of linear systems with delays in state and control

80. Relative controllability of nonlinear neutral systems with multiple delays in state and control

  1. Relative controllability of nonlinear neutral systems with distributed and multiple lumped delays in control

82. On compactoid and limited sets in non-Archimedean locally convex spaces

  1. The direct product of right zero semigroups and certain groupoids

84.A study of the Hubbard-Hirsch model within the Hartree-Fock Approximation (HFA)

  1. Correlation between perturbation and variation methods in the study of strongly correlated electron systems

  2. Logarithmic perturbation theory: Applications and limitations

  3. Streaming instability in a velocity–sheared dusty plasma

88. Excitation of low-frequency electrostatic instability on the auroral field lines due to precipitation electron beam

89. On iterative solution of non-linear equation

 


 

 

 


 
  1.  

Neutrino mass

 

by

Amagh Nduka

Departments of Physics and Mathematics,

Federal University of Technology, Owerri, Nigeria.

 

Abstract

 

The place of the neutrino in atomic theory and the mass of this particle are two problems that have received considerable attention for many decades. In spite of the heavy investment recourses, human material, theses problems have remained intractable. It turns out that geometrization of matter is a necessary prerequisite for the resolution of many problems of considerable current interest. In this paper we discuss the geometrization of matter, and deduce therefore the mass of the neutrino.

 

Pg 1 – 4

 

Click to top

 

 

 

  1.  

 

New One-Boson-Exchange Potential functions

by

J. O. Fiase, F. Gbaorun and +L. K. Sharma+

Department of Physics, Benue State University, Makurdi, Nigeria.

+ Department of Physics, University of Botswana, Gaborone, Botswana.

 

Abstract

 

A new one-boson-exchange potential (OBEP) is derived by fitting the oscillator matrix elements of the sum of the OBEP functions to those of the matrix elements derived by the lowest order constrained variational (LOCV) technique.  The results give a reasonable fit to the OBEP model.

 

pg, 5 – 10

 

Click to top

 

 

 

  1.  

Contribution of oblateness of the sun to radar sounding according to Newtonian mechanics

 

                                                                      by

Y. Y. Jabil and S. X. K. Howusu

Department of Physics, University of Jos, Nigeria.

 

Abstract

 

The Newtonian theory of radar sounding in the gravitational field of a spherical sun is well known [1]. It is now well established that most of the astronomical bodies including the sun are spheroidal (proplate or oblate) in shape [5,11,12]. The Newtonian mechanics has been used to resolve satisfactorily the radar sounding phenomenon to the order of c-5 within the gravitational field established by the homogenous spherical massive sun. In this paper the Newtonian mechanics shall be used to resolve satisfactorily the radar sounding phenomenon within the gravitational field established by the homogenous spheroidal oblate massive sun.

 

Pg 11 - -14

 

Click to top

 

 

  1.  

 

Theoretical model analysis of molecular orientations in liquid protein dielectrics

 

by

A. A. Laogun and N. O Ajayi

Department of Physics, University of Benin, Benin City, Nigeria.

 

Abstract

 

In this study, some theoretical model functions have been used to explain the molecular behaviour of four different types of proteins; human haemoglobin, Insulin, egg-white lysozyme and b - globulin molecules in solution. The results of the computational fitting procedures showed that the dielectric dispersion of the protein molecules generally followed the Debye and Cole-Cole functions. The dielectric parameters obtained from the dispersions, relating to the structural and electrical properties of the molecules were tabulated. The relationships between the dispersion amplitude D and the molecular dipole moment m of the proteins and also between the relaxation time t and the energy of activation DH of the molecules have been highlighted. The molecular interpretation of the polarization effects responsible for the dielectric dispersions have been discussed. 

Pg 15 - -20

 

Click to top

 

 

  1.  

Optmizied random phase approximation for the phase diagram of C60  material

 

by

F. Matthew-Ojelabi and K. A. Aduloju

Department of Physics, University of Ado-Ekiti, Ado-Ekiti. Nigeria.

 

 

Abstract

 

This paper determines the phase diagram of C60 fluid by an efficient and robust optimized random phase approximation (ORPA) method of Pastore et. al (1995), imposes physical requirements as in the original ORPA scheme with a view to  achieving consistency within the liquid structure factor. Our perturbation/variational approach for the Helmholtz free energy of the C60 molecules is based on the Lennard-Jones intermolecular interaction. We observe that higher accuracy is obtainable by treating all the grid points within the exclusion hole of the pair distribution function as independent variables. Our numerical results show appreciable improvement in both the thermodynamic functions and the structure factor.

 

Pg 21 -26

 

Click to top

 

 

  1.  

 

The F-Region Equatorial Ionospheric Electrodynamics Drifts

 

by

Oyedemi S. Oyekola1 and Emeagi E. Iheonu2

1Department of Physics, University of Ibadan, Ibadan, Nigeria (osoyekola@yahoo.com)

2Building Research Department, Building Physics Unit, NBRRI, Km 10, Ota-Idiroko Road, Ota, Ogun State, Nigeria (e-mail: eeiheonu@yahoo.com)

 

Abstract

 

The ionospheric plasma drift is one of the most essential parameters for understanding the dynamics of ionospheric F-region. F-region electromagnetic drifts are calculated for three seasonal conditions from ionosonde observations acquired during quiet period of a typical year of high and low solar activity at Ibadan (7.4oN, 3.9oE, dip 6oS), Nigeria. The vertical plasma drifts derived from h’ (f) ionosonde data are compared with vertical drifts obtained by incoherent scatter radar and AE-E satellite measurements during nighttime periods under similar solar and geomagnetic conditions. We find comparable variability among the ionosonde drifts at Ibadan, Jicamarca VHF radar drifts, and AE-E satellite drifts during high solar flux and geomagnetic quiet conditions at equinox and solstices periods. The equinoctial average evening upward drifts enhancements by the three methods are roughly similar and occur at the same local time (19 LT) for all the seasons. Additionally, the evening reversal time from upward daytime to downward nighttime does not vary much except during the winter months; and occurs earliest in summer and equinox, but least during winter period. Also the data indicate asymmetry of evening reversal times about the dip-equator between the Peruvian, Indian, and the African equatorial regions. Our observations are in conformity with some results obtained at other equatorial ionospheric stations

 

Pg 27 – 34

 

Click to top

 

 

  1.  

 

On temperature control of buildings by adobe wall design: Duffin and Knowles’ exponential transmission line model revisited

 

by

E. E. Iheonu

Building Physics Unit

Nigerian Building and Road Research Institute Ota, Ogun State, Nigeria.

 

Abstract

 

Duffin and Knowles (Solar Energy, Vol. 27(3), 1981) developed an equation for attenuation factor of an Adobe wall modelled as 4-terminal electrical transmission line network. The modelled electrical system and the derived formula for the real attenuation factor of the wall have been critically examined and then modified by taking into cognisance the true conceptualisation of a physical filter network as analogue of the thermal wall. By comparing results from the two versions of the exponential transmission line network models, it is shown that the effect of the correction on the attenuation factor is significant.

Pg 35 – 40

 

Click to top

 

  1.  

 

First order normalization in the perturbed restricted three–body problem with variable mass

by

Jagadish Singh

Department of Mathematics, Faculty of Science,

Ahmadu Bello University, Zaria, Nigeria

e-mail jgds2004@yahoo.com

 

Abstract

 

This paper performs the first order normalization that will be employed in the study of the nonlinear stability of triangular points of the perturbed restricted three – body problem with variable mass. The problem is perturbed in the sense that small perturbations are given in the coriolis and centrifugal forces. It is with variable mass as the mass of the third body varies with time. It is found that these perturbations and varying mass are capable to bring a change in the Lagrangian function, and consequently in the basic frequencies. They become successful in affecting the angle coordinates but remain unsuccessful in changing the action momenta coordinates. The transformation utilized for reduction of the second order part of the Hamiltonian to the normal form is also dependent on the perturbed basic frequencies.

 

Keywords: Normalization, Perturbed, RTBP with variable mass,

 

Pg 41 – 46

 

Click to top

 

  1.  

 

A 2-dimensional finite element simulation of cooling in castings

 

by

John A. Akpobi and Imafidon A. Lawani.

Department of Production Engineering, University of Benin, Nigeria

 

Abstract

 

In this work we present a 2 dimensional finite element simulation of the cooling process in castings. A one way coupling +technique was used to predict the behavior of thermal strains and stresses from the temperature history of casting. The temperature distribution across the casting at different times, the cooling pattern of the casting in different cooling media, the cooling times and the build up of thermal strains and stresses were simulated in this work. The model was validated with experimental cooling times in the scenarios considered.

 

Keywords: Casting, one way coupling, thermal history, thermal strains and stresses

 

Pg 47 – 58

 

Click to top

 

 

  1.  

 

Analysis of Stokes waves theory as a diffusion problem

 

by

E. O. Okeke1 and B. S. Oyetunde2

1Department of Mathematics, University of Benin, Benin-City

2Department of General Studies, Mathematics and Computer Science Unit,

Petroleum Training Institute, Effurun, Warri.

 

Abstract

 

This mathematical model concerns the theory of Stokes waves. These wave types belong to the class of ocean surface waves found in deep and intermediate waters.  In this consideration, the fifth order expansion was obtained using Korteweg de Vries equation with diffusion term. This study suggests that the phase velocity grows with increase in wave steepness whilst the group velocity shows the opposite tendency .The effect of diffusion introduced through depth distribution is obvious as the solutions apparently depend strongly on the water depth in inverse form. Interestingly, this analysis strongly suggests that the peak for potential energy lies between second and third order solutions while that of kinetic energy attains the peak at second and then becomes fairly stable. High seismic response associated with sea-bed motion corresponding to second order solution strongly support the result. However, the effect of additional terms on the wave profile appears somewhat insignificant. The wave profile of first order to fifth order in this consideration remains unchanged as expected.

 

Pg 59 – 68

 

Click to top

 

 

11.      

 

Remarks on thermal explosions in the early evolution of the earth.

 

By

R. O. Ayeni, A. O. Popoola and O. J. Fenuga

Department of Pure and Applied Mathematics

Ladoke Akintola University of Technology, Ogbomoso, Nigeria

 

1.0       Introduction

 

Earth’s origin and the formation of its shells are fundamental problems of natural sciences. Owing to the joint efforts of space physicists and space chemists, planetologists and geophysicists the main physicochemical processes have been studied, computer models of planet formation from smaller bodies of asteroid dimensions have been developed and the times of planet formation supported by isotope data have been calculated. It is evident that during the formation of the main structural units of the Earth – its core and mantle – there was a considerable energy generation due to gravitational differentiation (equivalent heat by 2500 0C) [3].

            The presence of fluid core of an electrically conducting fluid permits the interaction of the fluid flow and the magnetic lines of force to produce an electromotive force (e.m.f) which helps the magnetic field to regenerate itself. The subject of the study of the processes of regeneration of a magnetic field is known as the dynamo theory [2].

            During the gravitational differentiation (GD) in the large material volume in the Earth’s gravitational field the generated potential energy becomes heat due to viscous dissipation [3].

            In this paper we study the time evolution of the Earth. Of course, the planetary scales and characteristic geologic times of the thermal processes in the interior differ from the corresponding characteristics of the classical thermal explosion, but, and in essence and form, they are analogous to the thermally activated processes [3].

 

Pg 69 – 70

 

Click to top

 

  1.  

 

An investigation of groundwater condition in Agbede by Geelectrical resistivity method.

 

by

Otobo Egwebe1, C. O. Aigbogun2, and S. O. Ifedili.1

1 Department of Physics, University of Benin City.

2 Department of Physics, Igbinedion University, Okada, Edo State.

 

 

Abstract

 

Vertical soundings (VES) for the purpose of drilling groundwater boreholes for the inhabitants were conducted in Agbede to determine: the depth to the aquifer (Ajali Formation which consists of porous and permeable coarse sandstones); the thickness of overlying aquiclude (Imo Shale which consists of non porous/ permeable thick clays) and to locate where the small lenticular sands within the Imo Shale called perched aquifer exists. Perched aquifers are hydraulically separated, are relatively small, and they occur above the water table when there is an impermeable layer of rock (aquiclude) above the main aquifer.  The VES curves of the area were qualitatively interpreted and the result showed an ascent at the first decade (dry top soil), a decent at the second decade (Imo Shale) and with the right most segment ascending int6o the third decade which is an indication of the presence of the Ajali Formation below the Imo Shale.  The geoelectric section from the from the VES revealed that the Ajali Formation could not be encountered even at a depth of 494.03m, indicating that the clay is as thick as 500m. Also perched aquifer could be encountered between the depths of 52.76-55.43m with thicknesses 9.89-10.86m but not in all locations.

 

Pg 71 – 76

 

Click to top

 

  1.  

 

The application of geophysics in environmental impact assessment: A case study in Jeddo, Delta State, Nigeria

by

Otobo Egwebe

Department of Physics, University of Benin, Benin City.

 

 

Abstract

 

Geophysical study using the Schlumberger vertical electrical sounding (VES) was conducted with half current electrode spacing ranging from 1-215m. Also five boreholes were drilled to the depths, 15.2-30m close to five of the VES locations for the purpose of comparing the derived geoelectric sections from VES curves with the geologic sections from the boreholes. The results from VES curves showed the presence of clay of thicknesses, 15.2-26.4m at depths 0-4.4m in two VES locations, while sands of thicknesses,12.2-116.1m were exposed in seven VES locations. Also the logs derived from soil samples collected from the boreholes showed clay presence of thicknesses, 15.2-23.9m at depths 0-3m in the two boreholes close to the VES locations where thick clay presence was detected, while three boreholes showed exposed sands of thicknesses, 12.2-30m. The application of geophysics for the purpose of subsurface study in environmental impact assessment has been discussed.

 

Pg 77 - 82

 

Click to top

 

 

 

14.      

Characterization of formations and groundwater potential of Amai and Obiaruku in Delta State using resistivity and seismic refraction measurements

by

1E. C Okolie, 2F. C Ugbe, 3J. E. A, Osemeikhian

1Department of Physics, Delta state University Abraka, Nigeria.

2Department of Geology, Delta state University Abraka, Nigeria.

3Department of Physics, Ambrose Alli University Ekpoma, Nigeria.

 

 

Abstract

 

Obiaruku and Amai are two communities with remarkable high population due to their nearness to flowing waters which is one of the bases of early settlements. Although, the two towns are only 3 kilometres apart their geological and geophysical presentations vary remarkably. While Obiaruku is flanked by the early stage of the fast flowing North - South fresh-water river Ethiope, Amai has slow flowing filthy stream which spreads out and sometimes over flows its bank.            Moreover, while Amai has numerous hand dug wells which are filled up to 2.5 metres or less depending on the season under investigation, Obiaruku has no evidence of hand dug well all the year round. The disparities in presentations are of interest. It becomes necessary to carryout a geophysical investigation of the formation strata and groundwater potential for the ever growing population of these communities. Hence a characterization of the formations and groundwater distributions were carried out using Schlumberger array of electrical resisitivity and up-hole shooting of seismic refraction surveys. Twelve Vertical Electrical Sounding (VES) stations were sounded using Self Averaging System SAS ABEM 300C tarrameter and eight refraction sounding sites were shot using Seismograph OYO MESEIS 160mx. The study shows that while Obiaruku has QA and HA curve types, which have basically four or more distinct resistive layers, Amai consists of A-type curve which has mainly three or four distinct resistive layers. The soil formation in Amai is highly conducting clay while that of Obiaruku is mainly laterite. Moreover, while Groundwater is at 45 – 50 m depth in a region of unconfined aquifer at Obiaruku, it is as low as 20 m in a zone of confined aquifer at Amai.

 

 

Pg 83 -90

 

Click to top

 

 

  1.  

 

Variable order one-step methods for initial value problems I

by

G. C. Nwachukwu and F. O. Otunta 

Department of Mathematics, University of Benin, Benin City, Nigeria.

 

 

Abstract

 

A class of variable order one-step integrators is proposed for Initial Value Problems (IVPs) in Ordinary Differential Equations (ODEs). It is based on a rational interpolant.

 

Pg 91 -96

 

Click to top

 

 

  1.  

An application of the maximal independent set algorithm to course allocation

 

by

*V. V. N. Akwukwuma and K. C. Ukaoha,

Department of Computer Science, University of Benin, Benin City.

*e-mail: vakwukwuma@yahoo.com

 

 

Abstract

 

In this paper, we demonstrated one of the many applications of the Maximal Independent Set Algorithm in the area of course allocation. A program was developed in Pascal and used in implementing a modified version of the algorithm to assign teaching courses to available lecturers in any academic environment and it proved to be very effective.

 

Keywords: maximal independent sets, graphs, course allocation, bipartite graphs.

 

Pg 97 -106

 

Click to top

 

  1.  

The turning points in the solution of n-queens problem using backtracking method

by

1S. C. Chiemeke and 2E. O. Osaghae

1Department of Computer Science, University of Benin, Benin City, Nigeria.

e-mail: schiemeke@yahoo.com

2Department of Computer Science, Delta State Polytechnic, P.M.B 03,

Otefe-Oghara, Delta State, Nigeria.

 

Abstract

 

Conventional backtracking method has been the generally accepted method for solving n-queens problem. However, this method may prolong execution time for fairly large n-queens (example, n = 30) and most cases, failed to find solution to large n queens problem.  In this paper, we asserted that, even/odd numbered values of n-queens problem can affect the corresponding solutions of the standard backtracking. We also observed that, using a set of even and odd numbers, the odd number experience a turning point before the even numbers. The algorithm of the standard backtracking method was implemented in C programming language and, we used Microsoft Notepad as our output file to display the arrangement of the queens.

 

Pg 107 -114

 

Click to top

 

  1.  

 

Software package for analysis of completely randomized block design

by

*Onyinye Ifeyinwa Ojukwu and Julian Ibezimako Mbegbu

Department of Mathematics, University of Benin, Benin City, Nigeria 

 

 

Abstract

 

This study is to design and develop statistical software (package), OYSP1.0 which conveniently accommodates and analyzes large mass of data emanating from experimental designs, in particular, completely Randomized Block design.  Visual Basic programming is used in the design. The statistical package OYSP 1.0 when implemented on a micro computer gives an encouraging result

 

Pg 115 -120

 

Click to top

 

 

  1.  

 

Three algorithms for Egyptian fractions

by

Orobosa Izevbizua and Joseph Osemwenkhae

Department of Mathematics, University of Benin, Benin City

 

 

Abstract

 

The ancient Egyptians used a number system based on unit fractions, i.e. fractions with one in the numerator.  This idea let them represent any fraction  as the sum of unit fractions e.g  Further, the same fraction could not be used twice (so  is not allowed).  In this work we examine a number of algorithms for generating Egyptian fractions in more detail, implement them and analyze their performance.

 

Keywords: Unit fractions, Splitting Algorithms, Paring Algorithm, Distinct divisors, Length of Egyptian fraction, Lexicographic

 

Pg 121 -126

 

Click to top

 

 

  1.  

Measure synchronization in a coupled Hamiltonian associated with the motion of particles in a periodic potential

by

U. E. Vincent, *A. N. Njah, *A. O. Obawole and *M. T. Azeez

Department of Physics, Bisi Onabanjo University, Ago-Iwoye, Nigeria.

*Department of Physics, University of Agriculture, Abeokuta, Nigeria

 

Abstract

 

We report here, the existence of measure synchronization (MS) in a coupled Hamiltonian system associated with the motion of particles in a periodic potential of the pendulum type. We show that the oscillators can assume chaotic MS stares vis quasiperiodic measure desynchrononized state. In the chaotic MS state, the phase difference of the tow oscillators performs a stick-slip and random-walk-like motion analogous to the phenonomention of intermittency already established in the classical chaotic pendulum.

 

PACS: 05.45.Pq; 05.45. Xt; 05.45.Ac

Keywords: Measure synchronization; Hamiltonian systems; Chaos

 

Pg 127 - 136

 

Click to top

 

 

  1.  

Active control versus recursive backstepping control of a chaotic system

 

by

A. N. Njah

Department of Physics, University of Agriculture Abeokuta, Nigeria.

e-mail: njahabdul@yahoo.com

 

Abstract

 

In this paper active controllers and recursive backstepping controllers are designed for a third order chaotic system. The performances of these controllers in the control of the dynamics of the chaotic system are investigated numerically and are found to be effective. Comparison of their transient performances show that the rate of convergence of error is faster for the active controllers than for the recursive backstepping controllers. However, the flexibility in the choice of the control laws for recursive backstepping design gives room for further improvement in its performance and enables it to achieve the goals of stabilization and tracking.

 

PACS: 05.45.-a, 05.45.Pq, 05.45.Ac

Keywords: Active Control; Recursive Backstepping control chaotic system

 

Pg 137-142

 

Click to top

 

  1.  

Synchronization of Forced damped Pendulum via Active Control

by

A. N. Njah

Department of Physics, University of Agriculture, Abeokuta, Nigeria

e-mail: njahabdul@yahoo.com

 

Abstract

 

In this paper active controllers are designed to synchronize two identical forced damped pendula. The performance of the controllers in the synchronization of the chaotic dynamics of the two pendula, resulting from different initial conditions, is investigated numerically and found to be effective. Transition from nonsynchronous state via both temporary phase lock (TPL) and intermittent synchronous states to complete synchronous state was observed.

 

PACS: 05.45.-a, 05.45.Pq, 05.45.Ac

 

Keywords: Active Control; synchronization; chaotic pendulum

 

Pg 143 - 148

 

Click to top

 

23.      

 

Some thermodynamic non-Fermi liquid properties of correlated electron systems.

 

by

G. C. Asomba and D. U. Ugwoke

Department of Physics and Astronomy,

University of Nigeria, Nsukka, Nigeria.

 

Abstract

 

A mean-field Hamiltonian model has been used to investigate some thermodynamic properties of the normal states of non-Fermi liquid (NFL) systems,. This Hamiltonian is like that of the Bardeen-Cooper-Schrieffer model [Phys. Rev. 108 (1957) 1175] but differs from the latter in (i) being multiband, (ii) the gap in energy being a function of the hopping integral and (iii) band energies of electrons being dependent upon spin orientation. The Hamiltonian is, therefore, similar to the Paring t-model [Physica 258 (9166) 30] but differs from it in not incorporating hybridization term and hybrid pair superconductivity. The analysis of the model yields magnetic energy spectrum for  bands` and non-magnetic energy spectrum for the O (2p) bands. Inverse temperature dependences of electronic specific heat , entropy function  and pair susceptibility  are computed and exhibited. The specific heat dependence upon inverse temperature shows a linear form at very high temperature. It displays inverse-square-law temperature dependence, approximately, for lower temperatures. In the very low temperature range, the actual curve of the theoretical specific heat with temperature is rather like that of the  versus curve obtained for  and  down to millikelvin temperature. This is in contradistinction to the linear temperature dependence  of Fermi liquid systems. The specific entropy dependence on temperature shows correct physical response of systems to order (disorder) with varying temperatures. The pair susceptibility is linear at very high temperature and constant  at moderate/low temperatures. The latter is as in Fermi liquid systems, but the former is an NFL manifestation.

 

Keywords: Mean-field model, Green’s function, thermodynamic functions,  inverse temperature.

Pg 149 – 156

 

Click to top

 

 

24.      

Plasma heating by non-linear wave-Plasma interaction

by

I. M. Echi and A. Ojo

Department of Physics, University of Ibadan, Ibadan, Nigeria

 

Abstract

 

We simulate the non-linear interaction of waves with magnetized tritium plasma with the aim of determining the parameter values that characterize the response of the plasma. The wave-plasma interaction has a non-conservative Hamiltonian description. The resulting system of Hamilton’s equations is integrated numerically using fourth order Runge-Kutta scheme. It is found that for wave amplitude a as low as 0.01Bo the response of the plasma is remarkably different from the prediction of linear response theory. The response cannot be explained in terms of whether or not the wave frequency w is a harmonic of the ion cyclotron frequency W. The scaled drift velocity of the ions  and the scaled phase velocity of the waves  were found to be more relevant in explaining the response characteristics.  For >>, the plasma response is found to be chaotic while for <<, the response is either periodic or quasi-periodic. For » the waves do not interact with the plasma. The energy deposition (heating) by the waves in the plasma is found to be enhanced when the interaction occurs in the chaotic mode. In this mode, plasma diffusion is negligible suggesting that chaotic interaction of waves with plasma may enhance containment of the plasma.

 

Keywords: Wave-plasma-interaction, Phase-space, Poincare sections,   Chaotic-response, Quasi-periodicity.

 

Pg 157 – 166

 

Click to top

 

 

  1.  

On finitely many fixed points

by

J. O. Olaleru

Department of Mathematics, University of Lagos, Lagos, Nigeria.

email Address: olaleru1@yahoo.co.uk

 

Abstract

 

Let C be the finite union of closed convex sets in a complete metrisable locally convex space. If f: C → C with  compact, then f can be approximated by a map g: C → C which has only a finite number of fixed points. This result, which is a generalization of the result of Baillon and Rallis, is proved in this paper.

 

Keywords: fixed point, locally convex space, homotopy, 2000 AMS Mathematics Classification: 47H10, 46A03

 

Pg 167 – 170

 

Click to top

 

 

 

  1.  

 

Some remarks on certain Bazilevic functions

 

by

K. O. Babalola

Department of Mathematics, University of Ilorin, Ilorin, Nigeria

e-mail: abuqudduus@yahoo.com

 

 

Abstract

 

In this note we give some sufficient conditions for an analytic function f(z) normalized by f¢ (0) = 1 to belong to certain subfamilies of the class of Bazilevic functions. In earlier works, the closure property of many classes of functions under the Bernardi integral have been considered. The converse of this problem is also considered here.

 

Keywords: Bazilevic functions, analytic and univalent functions

 

Pg 171 – 176

 

Click to top

 

 

 

  1.  

On the successive coefficients of certain Univalent functions

 

by

K. O. Babalola

Department of Mathematics, University of Ilorin, Ilorin, Nigeria

e-mail: abuqudduus@yahoo.com

 

 

Abstract

 

The object of this paper is to study relationship between successive coefficients of some subclasses of the class of univalent functions in the unit disk. The result obtained is sharp, and is used to provide a new, short proof of the well-known conjecture of Robertson on the coefficient of close-to-convex functions.

 

Keywords: Successive coefficients, starlike, convex, close-to-convex, univalent functions

 

Pg 177 – 180

 

Click to top

 

 

  1.  

On a differential subordination of some certain subclass of Univalent function

by

Y. O. Aderinto

Department of Mathematics,University of Ilorin, Ilorin, Nigeria

 

Abstract

 

We generate some results for some particular subclasses of starlike and close-to-convex functions using Briot-Bouquet differential subordination method.

 

Pg 181 – 184

 

Click to top

  1.  

 

On the dynamic Stability of a quadratic-cubic elastic model structure pressurized by a slowly varying load

by

A. M. Ette

Department of Mathematics and Computer Science, Federal University of Technology

Owerri, Nigeria.

e-mail:tonimonsette@yahoo.com

 

 

Abstract

 

The main substance of this investigation is the determination of the dynamic buckling load of an imperfect quadratic-cubic elastic  model structure , which ,in itself, is a Mathematical generalization of some of the many physical structures normally encountered in engineering practice and allied fields. The load function in which the time variable is explicitly expressed, varies very slowly over a natural period of oscillation of the structure. The nonlinearity is quadratic-cubic in nature and multiple-scaling two-timing regular perturbation technique is utilized. The result shows that the dynamic buckling load depends on the first derivative of the load function evaluated at the initial time .Besides , it is established that it is possible to relate the dynamic buckling load to its static equivalent and this by-passes the  labour of repeating the entire arduous  process for different imperfection parameters .

 

 

Pg 185 – 196

 

Click to top

 

 

  1.  

Asymptotic solution on the dynamic buckling of a column stressed by a dynamically slowly varying load

 

by

A. M. Ette

Department of Mathematics and Computer Science, Federal University of Technology

Owerri, Nigeria.

e-mail:tonimonsette@yahoo.com

 

Abstract

 

This paper analysis the dynamic stability of a dynamically oscillatory system with slowly varying time dependent parameters. It utilizes the concept of multiple times scaling in an asymptotic evaluation of the dynamic buckling load of the imperfect elastic structure under investigation. Unlike most similar investigations to date , the time dependence is explicit in the formulation  and this creates a situation of non-autonomous differential equation that accurately models the dynamic stability of the structure .The dynamic buckling load is obtained nontrivially and the results are found to generalize  earlier results obtained for step loading situation. It is established that the results depend strongly on the first derivative of the load function evaluated at the initial time.

 

Pg 197 – 202

 

Click to top

 

 

  1.  

Dynamic analysis of a Bernoulli-Euler beam via the Laplace transformation technique

 

by

M. Jiya, Y. M. Aiyesimi, and A. A. Mohammed

Department of Mathematics and Computer Science, Federal University of Technology,

Minna, Nigeria.

e-mail: jiyason@yahoo.com

 

Abstract

 

In this paper the dynamic analysis of a simply supported Bernoulli-Euler beam subjected to a distributed load was investigated. The simplified form of the mathematical expression defining the dynamic displacement of the beam was formulated using the variational Indicator of the Hamiltonian principle. The method of Integral Transformation was used to obtain the series solution for the governing equation. The effect of the various beam parameters on dynamic deflection profile of the beam was simulated, it was observed that the contribution is mainly done by the first mode and higher modes of vibration can be neglected.

 

Pg 203 -210

 

Click to top

 

  1.  

The period of relaxation oscillations of a nonlinear system using singular perturbation methods

by

E. E. Joshua

Department of Mathematics, Statistics and Computer Science

University of Uyo, Uyo, Nigeria.

e-mail: joshie_en@yahoo.com

 

 

Abstract

 

We determine the period of relaxation oscillations of a physical system governed by the nonlinear Liénard equation ε x² + (ax2 - b) x¢ + x +cx3 = 0 where a, b, c > 0, 0 < ε << 1, using singular perturbation methods. These methods which involve considering matched asymptotic expressions of different layers yield a uniformly valid expansion for the above equation and hence the relaxation oscillations. The van der Pol equation is a special case of the above equation.

 

Pg 211-222

Click to top

33.     

On the steady state temperature profiles of biological tissues during microwave heating.

by

*F. A. Adebile and B. N. Akintewe

Department of Mathematical Sciences, Federal University of Technology

Akure. Nigeria.

*e-mail: eaadebiletri@yahoo,com

 

Abstract

 

The Maxwell equations are solved together with the Pennes Bio-heat equation analytically. The procedure of solution is provoked by the solution to the Maxwell equation.   The result revealed the effect of the model parameters such as: the thermal conductivity, blood perfusion coefficient, and the thickness of the tissues and the location of the effect of the electric field. Our result agrees with the results obtained by El-dabe et al (2003) the results are significant to medical experts and engineers. 

 

Key words: Maxwell equation microwave heating, Pennes Bio-heat Biological tissue equation steady state.  Author to which correspondence should be addressed

 

Pg 223 – 228

 

Click to top

 

  1.  

Self-similar solution for coupled thermal electromagnetic model during microwave heating of biological tissues.

by

*E. A. Adebile, B. N. Akintewe, O. K. Olaleye,. and V. Idoko

Department of Mathematical Sciences, Federal University of Technology, Akure, Nigeria.

*e-mail: eaadebiletri@yahoo.com.

 

Abstract

 

An investigation into the existence and uniqueness solution of self-similar solution for the coupled Maxwell and Pennes Bio-heat equations have been done. Criteria for existence and uniqueness of self-similar solution are revealed in the consequent theorems

 

Keywords: Self-similar variable, Maxwell equation, Pennes Bio-heat equation, Microwave heating, biological tissues.

 

Pg 229 – 234

 

Click to top

 

 

  1.  

Impact of electric and magnetic fields in a resistant medium on the velocity of a particle subject to varying path angles

by

1O. J. Fenuga and 2R. O. Ayeni

1Department of Mathematical Sciences, Olabisi Onabanjo University, Ago-Iwoye, Nigeria.

e-mail: fenuga_oj@yahoo.Co.UK

and

2Department of Pure and Applied Mathematics, Ladoke Akintola University of Technology, Ogbomoso, Nigeria.

e-mail: ayeni_ro@yahoo.Com

 

Abstract

 

In this paper, we compare the impact of electric and magnetic fields in a resistant medium on the velocity of a particle subject to varying path angles by using numerical integration of finite difference method. The results show that the magnetic field has much impact on the velocity than the electric field.

 

Pg 235 238

 

Click to top

 

 

  1.  

Vorticity determination in a hydraulic jump by application of method of characteristics

by

A. E. Eyo

Department of Mathematics, Statistics and Computer Science,

University of Uyo, Uyo, Nigeria

 

Abstract

 

The method of characteristics for solving systems of partial differential equations coupled with jump conditions is used in analysing flow downstream of a hydraulic jump instead of the normal analytical approach adopted in Hornung [1]. It is shown that the method of characteristics together with the jump conditions can correctly be used as an alternative method to determine the mean vorticity downstream of the hydraulic jump as a function of the Froude number and height ratio. The mean vorticity does not increase from zero as a function of Froude number minus one but, however, it approaches a constant value at large Froude number. The present work extends the model of Hornung [1] to include non linear velocity profile used in calculating the torque with a view to determining the mean vorticity. The result obtained by this method generalizes that of [1].

 

Pg 239 – 248

 

Click to top

 

 

 

  1.  

Hydrodynamic dispersion of a reactive solute in Electro-Osmotic flow using quadratic polynomials

By

 

O. T. Gideon

Department of Mathematics Statistics and Computer Science,

Kaduna Polytechnics, Kaduna, Nigeria.

 

and

 

Y. M. Aiyesimi

Department of Mathematics and Computer Science, Federal University of Technology, Minna

 

Abstract

 

The objective of this paper is to study the effect of the dispersion coefficients and the reaction parameter on the hydrodynamic dispersion of a reactive solute in electro-osmotic flow through the method of finite elements using quadratic Lagrange polynomials.

 

Pg 249 -256

 

Click to top

 

 

  1.  

 

Existence of a secondary flow for a temperature dependent viscous couette flow.

by

 

1S. O. Adesanya, 3O.J Fenuga , 4 O. O. Otolorin.

Department of Mathematical Sciences ,

Olabisi Onabanjo University, Ago Iwoye, Nigeria.

e-mail: adesanyaolumide@yahoo.com

2R .O. Rufai

Department of Mathematical Sciences

Lagos State University, Ojo, Nigeria.

5 R. O Ayeni.

Department of Pure & Applied Mathematics,

Ladoke Akintola University of Technology, Ogbomosho, Nigeria.

 

Abstract

 

We model a viscous fluid flowing between parallel plates. The viscosity depends on temperature. We investigate the properties of the velocity and we show that the temperature and velocity fields have two solutions. The existence of two velocity solutions is new. This means that there exist secondary flows 

 

Pg 257 – 260

 

Click to top

 

  1.  

 

A Continuous formulation of some classical initial value volvers by non-Perturbed multistep collocation approach using Chebyshev polynomials as basis functions

 

by

R. B. Adeniyi+, E. O. Adeyefa and M. O. Alabi*

Department of Mathematics, University of Ilorin, Ilorin, Nigeria.

 

Abstract

 

This paper is concerned with the construction of some classes of multistep methods for the numerical integration of initial value problems in ordinary differential equations.  For this purpose we employ the Chebyshev polynomials as basis function in a non-perturbed collocation approach.  The continuous schemes thus obtained yield four classes of initial value solvers namely the Optimal order methods, the Adams-Bashforth methods, the Adams-Moulton methods and the Backward differentiation formulae at appropriate grid points.  A theorem in support of the accuracy of the continuous schemes is also established.

 

Pg 261 – 274

 

Click to top

 

 

  1.  

Fairing NURBS curve by dual parameter optimization

 

by

John A. Akpobi and Ufuoma D. Egbedi

Department of Production Engineering, University of Benin, Benin City, Nigeria.

 

Abstract

 

The curve fairing problem has seen many innovations especially in Computer-Aided Design (CAD) applications where product design depend largely on aesthetic, producibility and functional requirements. A major factor for evaluating these requirements is the geometric fairness of the product being modelled. This paper addresses the geometric fairing problem in which we model the shape of the product using Non Uniform Rational B-Splines (NURBS). The concept of curvature plot is used to interrogate the curve for defects and the corresponding knot and weight (at the defective regions) are sequentially modified in a sense that a fair curve ultimately results. Finally, results of our implementation are presented to show the validity of the proposed scheme.

 

Keywords: NURBS, virtual array, convexity, knot vector, homogeneous coordinate vector,  inflection point, curvature discontinuity, curve fairing.

 

Pg 275 – 292

 

Click to top

 

 

  1.  

Perturbed segmented domain collocation Tau-method for the numerical solution of Second Order Boundary Value problems

 

by

O. A. Taiwo* and A. S. Olagunju

*e-mail: oataiwo2002@yahoo.com and allforgod2004@yahoo.com

Department of Mathematics, Faculty of Science, University of Ilorin, Ilorin, Nigeria.

.

 

Abstract

 

This paper concerns the numerical solution of second order boundary value problems using a Perturbed segmented domain collocation-Tau method.  The entire interval for which the problem is defined is partitioned into two segments and the solution technique is demonstrated on each of the segments.  The Chebyshev polynomials shifted as the case may be, into a given interval are used as a basis for a collocation solution via the perturbed collocation method for each segment.  For a given problem two different solutions are obtained, which are valid for different intervals within the domain.  Numerical examples are given to illustrate the efficiency, accuracy and computational cost of the method.

 

Keywords: Collocation, Segmented domain, Auxiliary equation, Partitioning, Residual equations

 

Pg 293 – 298

 

Click to top

 

  1.  

 

Viscous dissipation effects on the flow of a radiating gas between concentric elliptic cylinders

by

 

R. O. Oladele, J. A. Gbadeyan and O. A.Taiwo*

Department of Mathematics, University of Ilorin, Ilorin, Nigeria.

.

 

Abstract

 

The solution of a boundary layer flow problem often neglects the effects of viscous dissipation.  However, the present treatment incorporates these effects with a view to assessing their global contributions to velocity and temperature distributions in the flow field.  Hence, fluid motion induced between two differentially heated concentric elliptic cylinders is investigated under transient condition and significant viscous dissipation.  When the temperatures of the cylinder are large enough for radiative heat transfer to be significant.   The solution approach is via an explicit finite difference algorithm on a PC 1512 micro-computer.  The numerical results obtained for the two cases show that the velocity and the temperature of the fluid are increased as a result of increase in thermal internal energy of the fluid caused by viscous dissipation.

 

 

Pg 299 - 304

Click to top

 

 

  1.  

 

Radiation effect of magnetohydrodynamic flow of gas between concentric spheres

 

By

J. A Gbadeyan and A. S. Idowu*

Department of Mathematics, University of Ilorin, Ilorin, Nigeria.

*e-mail: idowu_ms@yahoo.com

 

Abstract

 

Time independent flow of fluid between two concentric rotating spheres permeated by magnetic filed is studied.  Prevailing mode of heat transfer is radiation while optically thin limit case is considered.  The mathematical model of the problem with the induced magnetic field is developed and the resulting differential equations were solved using perturbed numerical technique.  It is found that the magnetic field has no effect on the temperature distribution.  However, when the magnetic field is introduced a decrease in velocity is obtained with an increase in either radiation parameter or Reynolds number.

 

Pg 305 -314

 

Click to top

 

 

  1.  

 

Perturbation analysis on the dynamic buckling of a lightly damped spherical cap modulated by a slowly varying sinusoidal load (1)

by

 

A. M. Ette

Department of Mathematics and Computer Science

Federal University of Technology, Owerri, Nigeria

e-mail: tonimonsette@ yahoo.com

 

Abstract

 

This investigation makes a conscious effort at analytical determination of the dynamic buckling load of an imperfect lightly damped spherical cap modulated by a sinusoidally slowly varying dynamic load. Essentially, the formulation is that of an elastic nonlinear oscillatory system, with small perturbations and with coefficients that are harmonically and dynamically slowly varying. The imperfection is discretized into an axisymmetric and a non-axisymmetric mode which are also the shapes of the equally discretized buckling modes. The dynamic buckling load is obtained and is related to the static buckling load. This by-passes the labour of repeating the entire process for different imperfection parameters.

 

Pg 315 – 326

 

Click to top

 

 

  1.  

On the dynamic buckling of lightly damped cylindrical shells modulated by a periodic load

by

 

A. M. Ette

Department of Mathematics and Computer Science

Federal University of Technology, Owerri, Nigeria

e-mail: tonimonsette@ yahoo.com

 

Abstract

 

The dynamic buckling load of finite imperfect, lightly but viscously damped cylindrical shells subjected to a periodic load, is determined using the technique of multiple scaling (two-timing) regular perturbation analysis. The geometric imperfection, assumed deterministic, are also assumed small and are expanded in a double Fourier series. The dynamic buckling load is obtained asymptotically and the result is found to be implicit in the load parameter.

 

Pg 327 – 344

 

Click to top

 

  1.  

 

One Leg hybrid P-stable substitution LMM for oscilatory IVPs in ODEs.

by

M. N. O. Ikhile and M. V. Ayo

Department of Mathematics, University of Benin,, Benin City, Nigeria.

email: mnoikhilo@yahoo.com and vimayo10@yahoo.co.uk

 

 

Abstract

 

This presents P-stable successive substitution one-leg hybrid LMM for the numerical solution of oscillatory second order IVPs in ODEs without explicitly defined first order derivative. These problems occurs amongst others, in orbital mechanics where the methods to be presented finds ready applications and need not any a priori knowledge of the period of the solution of the defining ODE.

 

Pg 345 -354

 

Click to top

 

 

  1.  

 

Hessian Spectrum to perturbation factor for gradient method algorithm

by

J. O. Omolehin

Department of Mathematics, University of Ilorin, Ilorin, Nigeria

e-mail:emolehin-joseph@yahoo.com

 

 

Abstract

 

In this paper, the eigen values of the associated Hessian matrix of our control problem are considered for optimal selection of the perturbation factor  or perturbation parameter for gradient method. The perturbation factor is calculated as an n-dimensional vector as against real number. The numerical results generated compare favorably with the existing works.

 

Keywords: Hessian; Matrix; Gradient; Spectrum; Minimize C.R. Categories: G.1.7

 

Pgs 355 -362

 

Click to top

 

  1.  

Jacobian approach to optimal determination of perturbation parameter for gradient method

by

J. O. Omolehin*, K. Rauf*, B. Opawoye*, and W. B. Yahya†

•Mathematics Department, University of Ilorin, Ilorin, Nigeria

†Statistics Department University of Ilorin, Ilorin, Nigeria

 

Abstract

 

In this work, the optimal determination of the perturbation factor  or perturbation parameter for gradient method is considered. The spectrum analysis of the associated Jacobian of the associated matrix has laid the basis for the judicious selection of the perturbation factor. Numerical work is carried out to prove our hypothesis.

 

 

Keywords:  Hessian; Matrix; Gradient; Spectrum; Minimize C.R. Categories: G.1.7

 

Pg 363 – 370

 

Click to top

 

 

  1.  

Control approach to Queue Theory

by

J. O. Omolehin

Department of Mathematics,, University of Ilorin, Ilorin, Nigeria

 

Abstract

 

The rigid condition for simple queue problem is minimized by considering multiple channels through control approach. The result control problem is solved using Conventional Conjugate Gradient Method and the optimal system performance is obtained

 

Keywords: Queue; Gradient; Parameter; Minimize; Functional C.R. Categories G.1.7

Pg 371 – 378

 

Click to top

 

 

  1.  

A family of block methods for special second order initial value problems [I.V.Ps].

By

V. A. Aladeselu,

Department Of Computer Science, University Of Benin, Benin City, Nigeria.

 

Abstract

 

In this paper, efforts are directed towards generating a 2-block 2-point numerical method for solving the special second order initial value problems of the form Y// = F(X, Y), Y(0) = YO, Y/(0) = YOO  ..  The scheme so developed, is in the same line of thought as Shampine and Watts (1969, 1972) [9]; Chu and Hamltion (1987) [2]; Fatunla (1991)[3].  The scheme is of orders 5/6, zero-stable and convergent.   It is thus possible, with this scheme, to assign computational tasks at 2 points within the block to two different processors working simultaneously.

 

Pg 379 – 384

 

Click to top

 

 

  1.  

 

Numerical integrators for Stiff and Stiff oscillatory First Order initial value problems

by

V. A. Aladeselu,

Department of Computer Science, University of Benin, Benin City, Nigeria.

 

Abstract

 

In this paper, efforts are geared towards the numerical solution of the first order initial value problem (I.V.P) of the form Y/ = F(X,Y), XÎ[ a, b]  , Y(a) = Y0, where  Y/ is the total derivative of Y with respect to X..  The scheme so developed for the stated equation is in the same line of thought as Fatunla (1980). It is of order 6, L-stable and exponentially fitted.

 

Pg 385 – 390

 

Click to top

 

 

  1.  

Periodic solutions of periodic differential equations

 

by

F. A. J. Bello

Department of Mathematics and Statistics, Kwara State Polytechnic, Ilorin

 

Abstract

In this paper we extend the work of Bello [4] where he considered the periodic solutions of certain dynamical systems inside a cylindrical phase space with differential equations of the form       (+)

with the property that there is a  and a natural number K such that                                                    (**)

with necessary and sufficient condition that the
fundamental matrix
 of the characteristic equation                                            (***)

of (*) have negative real parts (See [1], [7]),  is stable asymptotically. The extension considered the periodic solutions of the differential equations of the type

                                        (****)

with the property (**). The periodic solutions and the asymptotic behaviour of the solutions were investigated and analysed. Some theorems were proved and examples given to illustrate certain properties of the solutions.

 

Pg 391 - 398

 

Click to top

 

 

  1.  

A generalised interpolating post–processing method for integral equation

By

V. U. Aihie

Department of Mathematics, University of Benin, Benin City, Nigeria.

 

Abstract

 

Interpolating post-processing method for integral equation has been demonstrated to be superior to the iteration method by Qun Lin, Shechua Zhang and Ningning Yan.  They demonstrated that it is of order .  This paper describes the generalization in the choice of h, the mesh size which leads to a higher order of  (where ) and hence an improved accuracy of the method.

 

Keywords: Integral equation, interpolation post-processing, super  convergence.

 

Pg 399 - 402

 

Click to top

 

 

  1.  

On the existence and uniqueness result for a two-step reactive-diffusive equation with variable pre-exponential factor

 

by

**P. O. Olanrewaju, **R. O. Ayeni,**A. O. Ajala,**O. Adebimpe, and *A. O. Ajayi

**Department of Pure and Applied Mathematics , Ladoke Akintola University of Technology, Ogbomoso, Nigeria.

e-mail: Oladapo_anu@yahoo.ie

*Department of Computer Science and Engineering, Ladoke Akintola University of Technology, Ogbomoso, Nigeria.

 

Abstract

 

We examine the existence and uniqueness result of the steady-state solutions for the exothermic chemical reactions taking the diffusion of the reactants in a slab into account and assuming Arrhenius dependence with variable pre-exponential factor.              We establish the criteria’s and conditions for existence and uniqueness of solution for the newly formulated problem. It is shown that if and where positive constants are then the newly formulated model will have only one solution.  We further discovered that there are certain values for n, m, r and b that the problem can accommodate for solution to be stable. Similarly, Frank-Kamenetskii parameters d1, d2 must not exceed some values for the solution to exist and at the same time stable. Finally, the Frank-Kamenetskii parameter must not exceed the critical value for the solution to have physical implication or application and r must not be large for convergence of the solution (i.e r < 1).

 

Keywords: Exothermic chemical reaction, variable pre-exponential factor,  two-step Arrhenius reactions                             

 

Pg 403 - 408

 

Click to top

 

 

  1.  

On a Subclass of analytic functions

 

by

Abiodun Tinuoye Oladipo

Department of Pure and Applied Mathematics

Ladoke Akintola University of Technology, Ogbomoso, Nigeria

e-mail: atlab_3@yahoo.com

 

Abstract

 

Abstract. In this work we establish some conditions for univalence and our results include starlikeness, convexity and close-to-convexity

 

Keywords: Analytic, Univalent, Starlikeness, Convexity, Close-to-convexity Salagean derivative.

 

Pg 409 – 412

 

Click to top

 

 

  1.  

Heuristic framework for parallel sorting computations

 

by

E. D. Nwanze and E. E. Obasohan

Department of Computer Science, University of Benin, Benin City

 

Abstract

 

Parallel sorting techniques have become of practical interest with the advent of new multiprocessor architectures. The decreasing cost of these processors will probably in the future, make the solutions that are derived thereof to be more appealing.  Efficient algorithms for sorting scheme that are encountered in a number of operations are considered for multi-user machines. A heuristic framework for exploiting parallelism inherent in some of these schemes are worthy of investigation and valid suggestions are given for adequate implementation by associating processors in a multiprocessor platform. This exercise involves a closer investigation of the associated savings in employing simultaneous sorting techniques for, sayprocessors. A deterministic time algorithm using processors will substantially reduce the run time for a sorting scheme and is considered to be asymptotically optimal.

 

Pg 413 – 422

 

Click to top

 

 

  1.  

A software for the RSA Encription

 

by

E. E. Obasohan

Department of Computer Science, University of Benin, Benin City

and

H. O. Omokaro,

Department of Mathematics, University of Benin, Benin City, Nigeria.

 

Abstract

 

In Omokaro 2003[12], we extended the RSA Congruence to a finite number of primes. The extended RSA Cryptosystem was later obtained in Omokaro 2004[13] as an analogue of the RSA Cryptosystem to obtain the extended RSA Cryptosystem. In this work we provide a software for the enciphering of data in RSA cryptosystem

                                   

Pg 423 - 432

 

Click to top

 

 

  1.  

Quantum computer gate simulations

by

Adetunmise C. Dada

Department of Physics, Obafemi Awolowo University,

Ile-Ife, Nigeria

email: techada@yahoo.com

 

 

Abstract

 

A new interactive simulator for Quantum Computation has been developed for simulation of the universal set of quantum gates and for construction of new gates of up to 3 qubits. The simulator also automatically generates an equivalent quantum circuit for any arbitrary unitary transformation on a qubit. Available quantum computer simulators attempt to emulate the various physical realisations of quantum computation, simulate existing quantum algorithms or are aimed at facilitating the development of new algorithms. However, because of the level of advancement and complexity of quantum computation algorithms, these simulators tend to be quite complex, at least from a novice’s point of view. As a result of this, beginners are often at a loss when trying to interact with them. The simulator here proposed therefore is aimed at bridging the gap somewhat, making quantum computer simulation more accessible to novices in the field.

 

Pg 433 - 446

 

Click to top

 

 

 

  1.  

Effective utilization of weighting adjustment for the estimates of means in survey non-response

by

 

*O. R. Oniyide and D. A. Agunbiade

Department of Mathematical Sciences

Olabisi Onabanjo University, Ago-Iwoye, Nigeria.

 

 

Abstract

 

This paper provides a useful application for comparison on the use of Adjusted Estimates (Weighting Adjustment) as against Unadjusted Estimates for estimate of Mean in survey Non-response .The use of response propensity and the predicted mean of the outcome variable for cell creation are stressed .The results from our empirical study emphasize the efficacy of Weighting Adjustment over the Unadjusted estimates .We adopt the following criteria: Variance, Bias and Mean Square Error in reaching our conclusion.

 

Keywords: Weighting adjustment, potential stratifiers, adjustment cells, non-Response.

 

Pg 447 - 452

 

Click to top

 

 

  1.  

Effect of queue discipline on the performance of a queueing system

by

 

1S. A. Ojobor and 2S. E. Omosigho

1Department of Mathematics and Computer Science, Delta State University, Abraka, Nigeria.

e-mail: ojoborsun@yahoo.com

2Department of Mathematics, University of Benin, Benin City, Nigeria.

 

Abstract

 

The effect of three queue discipline namely first in, first out (FIFO), last in first out (LIFO) and service in random order (SIRO) on some measures of performance of a single sever queue are examined. The measures of performance are average waiting time and queuing time.  The comparison of the systems were carried out by writing an appropriate program in BASIC to simulate the queue discipline. This is due to the versatile nature of simulation and the fact that it is extremely difficult to obtain numerical results mathematically for the single server queue when the queue discipline is not FIFO and the arrival process is non-stationary.  The approach adopted is to generate arrival time and service times for n customers through a single sever queuing system under each queue discipline. The measures of performance were calculated for each system using appropriate expressions. The result show that the average queuing time and average waiting time are higher when the queue discipline is LIFO, whereas the total idle time for all the systems were found to be same in most cases.

 

Keywords: Queues, waiting time, Queuing time & Service time.

 

Pg 453 - 456

 

Click to top

 

 

  1.  

A mathematical model for Lassa fever

by

1Daniel Okuonghae  and Robert Okuonghae

Department of Mathematics, University of Benin, Benin City, Nigeria

 

 

Abstract

 

A mathematical model for the dynamics of Lassa fever is presented. Contributions from regular contact with the species of rats that carry the virus that cause Lassa fever and infectious contact with those suffering from the disease is seen as significant in the spread of the disease. Steady states of the model are examined for epidemic and endemic situations. A second model that incorporates the effect of vaccination on a subset of the target population is proposed, although at the moment there is no vaccine against the disease. However our model shows that in the interim, control of the rodents carrying the virus and some isolation policy for infected individuals are the best strategies against the spread of the disease.

 

 

Keywords: Mathematical model, steady state, Lassa fever, epidemic, endemic

 

 

Pgs 457 – 464

 

Click to top

 

 

  1.  

Mathematical model for bird flu disease transmission

 

by

1T. T. Yusuf and  2K. O. Okosun

Department of Mathematical Sciences, Federal University of Technology, Akure.

e-mail: ttyusuf@yahoo.com1, e-mail: kazeem_oare@yahoo.com2

 

 

Abstract

 

Bird flu (Avian influenza) is a contagious disease of animals caused by viruses that normally infect only birds and, less commonly, pigs.  These viruses are highly species-specific, but have, on rare occasions, crossed the species barrier to infect humans. The world at large never considered it a serious threat to mankind until the outbreak in Asia, Europe, USA and now in Africa.  The aim of this paper is to use mathematical modelling to examine the population dynamics with respect to the disease and its transmission. The model population comprises birds and humans. The appropriate systems of ordinary differential equations formulated were solved numerically and the results were analysed.  The result shows that the spread of the virus will continue as long as we have infected birds and there is tendency of human infection sooner or later.

 

Pg 465 – 470

Click to top

 

  1.  

The effect of stochastic migration on an HIV/AIDS transmission model.

 

by

Simeon Chioma Inyama

Department of Mathematics and Computer Science,

Federal University of Technology, Owerri, Nigeria

 

Abstract

 

In [3] we developed a mathematical model of the transmission dynamics of HIV/AIDS in Nigeria. In this paper, we consider the effect of stochastic migrating into the susceptible class. A system of stochastic ordinary differential equations (SODEs) was then formulated. This was analyzed. Also the Fokker-Planck equation  is used to transform the system into a system of deterministic partial differential equation. This latter equation was analyzed and it was shown that the stochastic migration has no significant effect on the model.

                               

Keywords: Stochastic migration, HIV/AIDS, Susceptible, Fokker-Planck equation, SODE

 

Pg 471 -476

Click to top

 

64.   

Qualitative study of Kermack and Mckendrick’s epidemic model

by

 

Simeon Chioma Inyama

Department of Mathematics and Computer Science,

Federal University of Technology, Owerri

Nigeria

e-mail: scinyama2003@yahoo.com

 

 

Abstract

 

In this paper, we carry out a qualitative study of Kermack and Mckendrick’s epidemic model. We derive a special case of this model for recurrent diseases (relapse – recovery model). Using the new model, we investigate the severity of the epidemic and then test the stability of the original model. It is then shown that the number of invectives after a very long time from the inception of the epidemic is a constant. It is also shown that the steady state is unstable. Trajectories that help to know the extent of the severity are also presented. Through these trajectories it is shown that the severity of this epidemic can be estimated when the rate of infectiousness (r) and the removal rate (d.) are estimated.

                               

Keywords: Qualitative study, Kermack and Mckendrick’s epidemic model recurrent diseases, relapse – recovery model. Severity.

 

Pg 477 – 480

 

Click to top

 

 

65.    

Mathematical models to simulate the East African trypanosomiasis population dynamics.

 

by

Daniel Okuonghae and 1Joseph Osemwenkhae

e-mail josemwenkhae@yahoo.com

Department of Mathematics, University of Benin, Benin City, Nigeria.

 

 

Abstract

 

This paper presents mathematical models for the East African trypanosomiasis or sleeping sickness. It is aimed at modelling the population dynamics for the human and domestic animal victims as well as the dynamics of the tsetse fly population that acts as the vector that spreads the parasite causing this disease. Since sleeping sickness is caused by two protozoan parasites that are morphologically similar but cause dramatically different diseases in humans and domestic animals, this paper examines the East African sleeping sickness only. An extended model is provided to show the significance of infectious contacts between the tsetse flies and animals that serve as the reservoir for the parasite that causes this disease. Steady states for the models are also presented and analysed.

 

Keywords: Mathematical model, steady state, trypanosomiasis.

 

 

Pg  481 – 488

 

Click to top

 

 

 

  1.  

Thermal neutron counts and derivated charts

 

by

+Olusogo O. Odusote and Ayomide O. Balogun

Department of Physics, Olabisi Onabanjo University, Ago-Iwoye, Nigeria.

 

 

Abstract

 

The neutron diffusion equation was solved under a “single cylinder one group (thermal neutrons)” approximation. The resulting equation was applied with a mixing index,, for various formation matrices and porosities. The ratio of counts from two different detectors was plotted as a function of porosity for these formations. These plots are useful for wireline log interpretations.

 

Pg 489 - 492

 

Click to top

 

 

  1.  

On the fluctuating filtrate

by

*Olusogo O. Odusote,

Department of Physics, Olabisi Onabanjo University, Ago-Iwoye, Nigeria.

e-mail: sog_odusote@yahoo.com

and

Olamide O. Odusote,

Department of Chemical Engineering, Ladoke Akintola University of Technology,

Ogbomosho, Nigeria.

 

 

Abstract

 

We show by the application of the ‘stick-slip’ phenomenon, that, the filtrate through a porous medium could be oscillatory under low-intensity driving forces. The frequency of the oscillation is dependent on the nature of the porous medium and the external driving forces. It is, therefore, possible to characterize the medium by the use of low amplitude external driving forces.

Pg 493 - 496

Click to top

 

68.    

A new poof of multiple solutions of combustions problems

by

1R. O. Ayeni, 1A. M. Okedoye, 2F. O. Balogun, and 3F. I. Alao

1Department of Pure and Applied Mathematics Ladoke Akintola University of Technology, Ogbomoso, Nigeria

2Department of Mathematics, Adeyemi college of Education, Ondo, Nigeria

3Department of Industrial Mathematics, Federal University of  Technology, Akure, Nigeria.

 

Abstract

 

We revisit the combustion problem, for the plane (n = 1), cylinder (n = 2) and sphere (n = 3) vessels. Using polynomial approximations. We show that the problem has two (2) solutions.

 

Pg 497 - 498

Click to top

 

69.    

On the possibility of multiplicity of temperature fields in a microwave heating cancer therapy

 

by

R. O. Ayeni, A. M. Okedoye

Department of Pure and Applied Mathematics, Ladoke Akintola University of Technology, Ogbomso, Nigeria

and

E. A. Adebile

Department of Industrial mathematics, Federal University of Technology, Akure, Nigeria

 

 

Abstract

 

We investigate a steady temperature dependent perfusion during a cancer therapy. We show how the choice of perfusion could lead to more than one temperature fields which could lead to an undesired result.

Pg 499 - 502

Click to top

 

70.    

Unsteady Magneto-Hydrodynamic (MHD) flow of a uniformly stretched vertical permeable surface I in the presence of heat generation/absorption and a first order chemical reaction.

by

 

*A. M. Okedoye, T. Adeniran, S. O. Adewale and R. O. Ayeni

Department of Pure and Applied Mathematics Ladoke Akintola University of Technology Ogbomoso, Nigeria.

*e-mail: micindex@justice.com

 

 

Abstract

 

Numerical results are presented for the transient and steady state Velocity, Temperature and Concentration fields. These results are obtained by solving the partial differential equations describing the conservation, momentum energy and species concentration by an explicit finite – difference method in time – dependent form. It was discovered that a maximum exist which confirm that maximum velocity and temperature occur in the body of the fluid and not in the surface as previously reported. A parametric study was conducted and the results were presented and discussed.

 

Pg 503 - 510

Click to top

 

  1.  

Biomechanics of the brain; some remarks on Biot’s equations of consolidation theory with deformation-dependent permeability

by

 

R. O. Ayeni, A. W. Ogunsola and A. O. Popoola

Department of Pure and Applied Mathematics Ladoke Akintola University of Technology, Ogbomoso, Nigeria

and

O. O. Eweoya

Department of Anatomy, College of Health Sciences

Ladoke Akintola University of Technology, Ogbomoso, Nigeria

 

Abstract

 

We revisit models of hydrocephalus in the literature. In particular, we examine the class of models based on Biot’s theory of consolidation with fixed boundary forcing. Instead of fixed boundaries we take free boundaries. We prove existence and uniqueness of solutions. As in the fixed boundary forcing, we show   that in a free boundary, the pressure is higher when the permeability depends on deformation. On the other hand, the total filtration is lower. Unlike the fixed forcing, the effect of the deformation on permeability reduces over time:

 

Keywords: Consolidation theory, variable permeability, free boundary, upper and lower solutions.

Pg 511 – 516

Click to top

 

72.    

Relative null controllability of linear systems with multiple delays in state and control

by

 

R. A. Umana

Department of Mathematics and Computer Science

Federal University of Technology, Owerri, Nigeria

 

Abstract

 

Sufficient conditions for the relative null controllability of linear systems with time–varying multiple delays in state and control are developed. If the uncontrolled system is uniformly asymptotically stable, and if the linear system is controllable, then the linear system is null controllable.

Key words: Null controllability, multiple delays, time-varying.

Pg 517 - 522

Click to top

 

73.    

Relative controllability of nonlinear systems with multiple delays in state and control

 

by

R. A. Umana

Department of Mathematics and Computer Science

Federal University of Technology, Owerri, Nigeria

 

Abstract

 

Sufficient conditions are developed for the relative controllability of nonlinear systems with time-varying multiple delays in the state and control. The results are obtained by defining an appropriate control and its corresponding solution by an integral equation. This equation is then solved using the Schauder’s fixed point theorem.

 

Pg 523 - 528

Click to top

 

74.    

Criteria for exponential asymptotic stability in the large of perturbations of linear systems with unbounded delays.

by

 

Vincent A. Iheagwam

Department of Mathematics and Computer Science, Federal University of Technology, Owerri, Nigeria

e-mail: vinanyameleiheagwam@yahoo.com

 

Abstract

 

The purpose of this study is to provide necessary and sufficient conditions for exponential asymptotic stability in the large and uniform asymptotic stability of perturbations of linear systems with unbounded delays. A strong relationship is established between the two types of asymptotic stability. It is found that if the exponential estimate of the solution of a system tends to zero as t �¥ the system is said to be uniformly asymptotically stable. But if the solution of a system approaches the origin faster than any exponential function, then the system is said to be exponentially asymptotically stable. Utilizing the exponential estimate of the solution, stability criteria for the linear part of our system of interest is derived. With enough smoothness conditions on the perturbation function, and appeal made to Lyapunov’s stability results and some Gronwall-type inequalities the required stability results are established for the linear perturbation.

 

Keywords: Exponentially asymptotic stability, linear perturbation, stability in the large, exponential estimate. 

 

Pg 529 - 536

Click to top

 

 

75.    

On the convergence profile of a discretized scheme for a two-dimensional constrained optimal control problem

By

**O. Olotu and *S. A. Olorunsola

**Department of Mathematical Sciences,. The Federal University of Technology, Akure, Nigeria.

*e-mail: segolotu@yahoo.ca

*S. A. Olorunsola

Department of Mathematical Sciences, University of Ado Ekiti, Nigeria.

 

Abstract

 

The convergence profile of a discretized schame for an optimal control problem constrained by ordinary differential equation with matrix coefficients is examined. Various penalty parameters are considered for the penalty function method.  It is observed that convergence is exhibited for these penalty parameters after certain number of iterations with a predetermined interval of convergence.

 

Pg 537 - 542

Click to top

 

76.    

Relative controllability of nonlinear neutral Volterra Integrodiferential systems with delays in control

by

P. C. Jackreece

Department of Mathematics and Computer Science, Niger Delta University, Wilberforce Island,

Amasoma, Nigeria.

e-mail-preboj@yahoo,com

 

 

Abstract

In this paper we established sufficient conditions for the relative controllability of the nonlinear neutral volterra integro-differential systems with distributed delays in the control. The results were established using the Schauder’s fixed point theorem which is an extension of known results.

 

Pg 543 – 546

Click to top

 

  1.  

Stability of discrete control systems

by

Celestin. A. Nse

Department of Mathematics and Computer Sciences, Federal University of Technology, Owerri, Nigeria.

 

Abstract

 

Consider the discrete control system

                         (*)

for

We implore the notion of asymptotic controllability to show that, a system which can be stabilized by an arbitrary feedback can also be stabilized by a linear feedback .

Pg 547 - 548

Click to top

  1.  

Necessity and sufficiency conditions for the absolute null controllability for Linear delay perturbations

by

 

Celestin. A. Nse and R. A. Umana

Department of Mathematics and Computer Sciences

Federal University of Technology, Owerri, Nigeria.

 

 

Abstract

 

We are inspired by the works of Chukwu [1], Eke [2], Schinterdorf and Barmish [4] to unveil necessary and sufficient conditions for the absolute null controllability of a linear delay perturbed system with zero in the domain of null controllability.

Pg 549- 552

Click to top

 

 

79.   

Euclidean null controllability of linear systems with delays in state and control

By

 

Davies Iyai

Department of Mathematics and Computer Science,

Rivers State University of Science and Technology, Port Harcourt,  Nigeria.

email: davsdone@yahoo.com

 

Abstract

Sufficient conditions are developed for the Euclidean controllability of linear systems with delay in state and in control. Namely, if the uncontrolled system is uniformly asymptotically stable and the control equation proper, then the control system is Euclidean null controllable.

Keywords:   Admissible controls, Controllability, Delayed systems,Linear systems, Null controllability.

Pg 553 - 558

Click to top

 

80.   

Relative controllability of nonlinear neutral systems with multiple delays in state and control

by

R. A. Umana

Department of Mathematics and Computer Sciences

Federal University of Technology, Owerri, Nigeria.

 

Abstract

 

Sufficient conditions are developed for the relative controllability of nonlinear neutral systems with time-varying multiple delays in both state and control. The results are obtained by using Schauder’s fixed-point theorem.

 

Pg 559 -564

Click to top

 

  1.  

Relative controllability of nonlinear neutral systems with distributed and multiple lumped delays in control

 

by

 

R. A. Umana

Department of Mathematics and Computer Sciences

Federal University of Technology, Owerri, Nigeria.

 

Abstract

 

In this paper we study the relatie controllability of nonlinear neutral system with distributed and multiple lumped time varying delays in control. Using Schauder’s fixed point theorem sufficient conditions for relative controllability in a given time interval are formulated and proved.

                               

Keywords: Controllability, nonlinear neutral systems, distributed delays, time varying multiple lumped delays.

 

Pg 565 - 570

Click to top

 

82.    

On compactoid and limited sets in non-Archimedean locally convex spaces

 

by

 

Henry O. Omokaro

Department of Mathematics, University of Benin, Benin City, Nigeria.

 

Abstract

In [2] and [3] spaces in which every bounded subset is a compactoid was studied. Every compactoid set is limited but the converse is not true [3]. In this paper, we shall study some spaces in which every limited set is compactoid.

 

Keywords: Controllability, nonlinear neutral systems, distributed delays, time varying multiple lumped delays.

 

Pg 571 - 574

Click to top

 

  1.  

The direct product of right zero semigroups and certain groupoids

 

by

*E. E. David and Adewale Oladipo Oduwale

*Department of Mathematics and Statistics, University of Port-Harcourt, Port-Harcourt, Nigeria.

Department of Mathematics, University of Benin, Benin City, Nigeria.

e-mail:adeoduomoba@yahoo.com

 

Abstract

 

This paper investigates first the structure of semigroups which are direct products of right zero semigroups and cancellative semigroups with identity. We consider the relationship of these semigroups to right groups (the direct products of groups and right zero semigroups). Finally, we consider groupoids which are direct products of right singular semigroups and unipotent (one-idempotent) groupoids with identity.

 

Keywords: Decomposition, partition, band of, orthogonal, cancellative,  idempotent.

 

Pg 575 - 578

Click to top

 

84.    

A study of the Hubbard-Hirsch model within the Hartree-Fock Approximation (HFA)

by

 

Ben E. Iyorzor1, Robinson Okanigbuan2 and John O.A. Idiodi3

1,3Department of Physics, University of Benin, Benin City.

2Department of Physics, University of Mkar, Gboko, Benue State.

 

 

Abstract

 

Based on the Hubbard-Hirsch model, we studied the dynamical susceptibility and spin excitation of an itinerant electron system within the Hartree-Fock Approximation (HFA) by using a Green’s function technique.  We are able to arrive at the same results obtained by Zhang et al [1] who employed a Random-Phase Approximation (RPA).

 

Pg 579 - 582

Click to top

 

 

85.    

Correlation between perturbation and variation methods in the study of strongly correlated electron systems

by

 

Robinson O. Okanigbuan

Department of Physical Sciences University of Mkar, Mkar, Nigeria.

and

John O.A. Idiodi

Department of Physics, University of Benin, Benin City, Nigeria.

 

Abstract

 

The ground–state wave function and energy are calculated for two electrons subject to a one-band Hubbard Hamiltonian on a one dimensional lattice containing N electronic sites, N = 2,3,4,5,6, and a 3 x 3 cluster of the square lattice, using perturbation and variational methods.  The results from these two approximation methods are then compared with the result from exact calculational method.

 

Pg 583 - 594

Click to top

 

86.    

Logarithmic perturbation theory: Applications and limitations

by

 

G. Y. Ndefru and S. Duwa

Department of Physics, Bayero University, Kano, Nigeria

 

Abstract

 

The time independent, non-degenerate standard perturbation theory is compared with the alternate treatment of perturbation theory called logarithmic perturbation theory (LPT). For determining the non-degenerate ground state the LPT is, in principle, easier to apply than standard perturbation theory. This is because, as opposed to the standard perturbation method which requires the knowledge of the complete set of eigenvalues and eigenfunctions of the unperturbed system, for the LPT one only needs to know the ground state wave function of the unperturbed system, the energy correction to the next lower order and some easily computable coupling constants.  However, in reality, the LPT is a simpler method to apply when the ground state wavefunction is exponential in nature. But as shown here for trigonometric unperturbed wave function the LPT leads to integrals which have no analytical solutions thereby making LPT more difficult and less accurate method than the standard perturbation approach.

 

Pg 595 - 600

Click to top

 

87.    

Streaming instability in a velocity–sheared dusty plasma

by

                                                                                      Salihu S. Duwa

Department of Physics, Bayero University, Kano, Nigeria

e-mail: duwass@yahoo.co.uk;

 

Abstract

 

A two-stream instability, obtained from kinetic theory, of strongly velocity-sheared inhomogeneous streaming electron in a magnetized plasma in the presence of negatively charged dust is discussed. Various cold plasma approximations were considered and it is shown that when the diamagnetic effect of ion can be ignored, the excited mode could be dust lower hybrid-like. On other hand, if the dust is treated as immobile background, the excited wave is ion lower hybrid-like. In both cases, the growth rate is reduced due to the presence of the dust particles and the velocity shear scale length,, is on the order of (where k is wave vector) for the most unstable mode. An example is given from the plume.

 

Keywords: Ionosphere, Space, Dusty plasma.

 

Pg 601 - 606

Click to top

 

 

  1.  

Excitation of low-frequency electrostatic instability on the auroral field lines due to precipitation electron beam

by

 

*L. E. Akpabio and +E. J. Uwah

*Department of Physics, University of Uyo, Uyo, Nigeria.

+Department of Physics University of Calabar, Calabar, Nigeria.

e-mail: leabio 2002 @yahoo. Com

 

Abstract

 

Low-Frequency Electrostatic Instability That Is Observed By Both Ground Facilities And Satellites Have Been Studied In The Auroral Acceleration Region Consisting Of Hot Precipitating Electron Beam From The Magnetosphere, Cold Background Electron And Ion Beam Moving Upward Away From The Earth Along The Auroral Field Lines. The Model Distribution For Both The Electron And Ion Are Taken, As Drifting Maxwellians While The Cool Background Electron Is Maxwellian. The Excited Mode And Growth Rate For The Resonant Instability Driven By The Precipitating Electron Beams Are Derived. We Also Discuss The Growth Rate And The Real Frequency Of The Resonant Instability. It Is Also Shown That, The Precipitating Electrons Can Generate Low-Frequency Electric Field Fluctuations (Lefs) Within The Frequency Range 55.4Hz To About 174.7Hz.

Pg 607 - 610

Click to top

 

89.   

On iterative solution of non-linear equation

 

by

*O. Ogbereyivwe

Department of Natural and Applied sciences, Federal polytechnic, Auchi, Nigeria.

and

O. Izevbizua.

Department of Mathematics, University of Benin, Benin City, Nigeria.

 

 

Abstract

In solving non – linear equations by iterative method, Ohirhian (1994), (2005) [4],[5] developed a new algorithm based on cubic interpolation for solving non- linear equations of degree 1 to 3. The algorithm was found to be faster than the Regular falsi and the Newton Raphason method. This paper extend the algorithm to solving non linear equations of degree n by deriving a general formular, also some of the iteration procedures are reviewed for ease in computation

 

Pg 611 - 615

Click to top