[en] The magnetohydrodynamic unsteady flow of a visco-elastic liquid (Rivlin-Erickson) near a porous wall suddenly set in motion has been studied with heat transfer including heat generating sources or heat absorbing sinks. The constitutive equations of continuity, velocity and temperature of visco-elastic liquid are obtained in cartesian co-ordinates. Regular perturbation technique is employed to solve the equations. Expressions for velocity, temperature, shear stresses and the rates of heat transfer are obtained. Velocity profiles and temperature profiles are shown in graphs where as skin frictions and Nusselt's numbers are entered in tables for various values of the fluid parameters R_c, P, G and the magnetic parameter M, source parameter S. It is observed that the elasticity of the fluid influences the velocity field to great extent and the strength of the external transverse magnetic field modifies the flow appreciably. Temperature of the fluid is largely affected by the presence of the heat source/sinks. The rate of heat transfer changes with Prandtl number P and source parameter S. (author)

[en] Contradicting interpretations of the nuclear force as given by two contrasted approaches like the meson theory and the quantum chromodynamics, are overcome here by reviving the basic electromagnetic laws which are applicable on the existing charged sub-constituents in nucleons. On this basis, considerable charge distributions in nucleons as multiples of 2e/3 and -e/3 are determined after a careful analysis of the magnetic moments and the results of the deep inelastic scattering. Basic equations derived from the distributed charges of oriented spins of nucleons give strong and short ranged forces leading exactly to the binding energies of deuteron and other nuclei. According to these interactions, p-p and n-n systems repel and only the p-n bonds form rectangles and closely packed parallelepipeds providing an excellent description of nuclear properties. In this dynamic subject, such contrary forces create structures of saturation and of finite number of nucleons. They also invalidate the charge independence hypothesis and differ fundamentally from the central potential and the effects of the Pauli principle of the electronic configurations responsible for the development of two different models like the Fermi gas and nuclear shell. There are two kinds of p-n bonds, which imply anisotropy, leading often to elongated shaped of vibrational and rotational modes of excitation, while the surface tension contributes to the creation of non-elongated shapes with stable arrangements. Finally, for A>40 a type of shell structure provides new rules for understanding the structure of magic nuclei for N>Z and the increasing ratio N/Z with A. (author)

[en] In this paper, an attempt has been made to study the flow of Rivlin-Ericksen visco-elastic fluid between two inclined parallel planes in presence of gravity and uniform transverse magnetic field. It has been assumed that the lower plane is at rest and the upper plane is moving with a transient velocity in the first case, while in the second case it is moving longitudinally with a periodic velocity. In both cases the fluid velocity and flux of fluid have been obtained by variable separation technique. These results are then deduced for the case of visco-elastic Maxwell fluid taking the fluid to be electrically conducting and placed in presence of a uniform transverse magnetic field. Further, when the magnetic field is absent the corresponding results are obtained by passing to the limit as uniform magnetic field tending to zero. Moreover, the titled problem has also been solved in case of inviscid fluid in both cases of hydromagnetic flow and flow in absence of magnetic field. Thus the present problem is focused to a wide range of flow problems of different types of fluid models. (author)

[en] In the present investigation, the combined effect of free and forced convection on the MHD coupled flow of a viscous, electrically conducting fluid through a channel bounded by a highly porous medium is considered with a temperature field taken as the sum of a linearly varying longitudinal part and an unknown transe distribution. The effects of various parameters on the velocity and temperature fields and on the induced magnetic field are investigated and discussed. (author)

[en] An unsteady free convection MHD flow of an incompressible electrically conducting viscous fluid past between two heated horizontal plates is studied under the action of a uniform transverse magnetic field with the heat transfer including heat generating sources or heat absorbing sinks. The velocity and temperature profile is found due to the effect of the deflection of a strong magnetic field on the MHD flow between heated plates. The velocity and the temperature profiles are plotted graphically for the different values of the magnetic parameter M and source parameter S. (author)

[en] The laminar convection flow of an electrically conducting second order visco-elastic fluid in porous medium down an inclined parallel plate channel in presence of uniform transverse magnetic field has been studied. The plates are maintained at temperatures that decay with time. The problem is studied firstly, under variable density and viscosity of the fluid that causes stratification effect, secondly the effect of induced magnetic field under constant fluid properties. Solutions are obtained using perturbation method in both cases, the distributions of fluid velocity, particle velocity, and fluid temperature are shown graphically for different values of stratification factor, magnetic Hartmann number, magnetic Reynolds number and porosity of the medium. The expressions for viscous drag at the plates, rate of heat transfer at the plates and the flow flux for fluid and particle are also obtained. (author)

[en] The triple differential cross section for the ionization of atomic hydrogen by electrons is analysed in the case of coplanar symmetric geometry within the framework of high energy higher order Born approximation. It can be shown that the variation in average excitation energy is highly affective to the second and third Born terms. The present result tends to betterment with increase in average excitation energy. (author)

[en] Free convection and mass transfer in the flow of an electrically conducting, incompressible, viscous rotating liquid past a vertical porous plate in porous medium embedded with non-conducting, solid spherical and uniformly distributed dust particles has been studied. It has been observed that when the Schmidt number increases (i) the concentration of species and (ii) the mass transfer decrease besides the heat transfer and temperature profiles, decreases exponentially with time. (author)

[en] Unsteady flow of a visco-elastic fluid through porous media bounded by a rectilinear pipe of uniform cross-section as a parallelogram has been studied in presence of transverse magnetic field. The motion takes place under the influence of time dependent pressure gradient. To solve the problem variable separable method has been used. The solution of two particular cases has also been obtained. (author)

[en] The combined free and forced convection effects on the MHD flow of a visco-inelastic fluid (Reiner-Rivlin) through a channel without considering dissipation energy are studied. The constitutive equations of the problem have been formulated taking all the physical variables dependent on Y only. These equations of continuity, motion and energy are solved by non-dimensionalising the equations first and then by applying regular parameter perturbation method. Since the fluid is conducting, non-dimensional equations of magnetic fluid and electric field are also solved to find the value of H and E. The velocity and temperature field are represented by graphs, shear stresses at the walls and Nusselt numbers are entered in tables. It is observed that the velocity and temperature profiles are modified by the elastic parameter R_c, magnetic parameter M and Grashof number G. (author)