Anil K. Agrawal

Some Bianchi-type cosmological models in a new scalar-tensor theory

Bianchi type I, III, V, VI0, and Kantowski-Sachs type models have been investigated in a scalar tensor theory developed by Saez and Ballester (1985) and Saez (1985). The dynamical behaviour of the models has also been analyzed.

Homogeneous anisotropic cosmological models with variable gravitational and cosmological constants

The Einstein field equations with perfect fluid source and variable Λ andG for Bianchi-type universes are studied under the assumption of a power-law time variation of the expansion factor, achieved via a suitable power-law assumption for the Hubble parameter suggested by M. S. Berman. All the models have a power-law variation of pressure and density and are singular at the epocht=0. The variation ofG(t) as 1/t and Λ(t) as 1/t2 is consistent with these models.

Bianchi type-II, VIII, and IX in certain new theories of gravitation

Bianchi type-II, VIII, and IX models have been investigated in scalar-tensor theories developed by Saez (1985), Saez and Ballester (1985), and Lau and Prokhovnik (1986) (under the assumption of a certain relationship between the cosmological term λ and the scalar field ψ). The dynamical behaviour of these models has been studied.

Loading problem and resource considerations in FMS: a review

Abstract The loading problem in FMS is an important part of the short term planning problem concerned with allocating operations and resources to machines subject to relevant capacity constraints. This paper presents a review of the loading problem formulations and solution methodologies with a special emphasis on resource considerations and the integration of loading with other neighboring problems. Certain differences related to loading in FMS and conventional manufacturing systems are discussed. Comments and suggestions for future research are also presented.

Hall effects on convective hydromagnetic flow past a flat plate

Abstract Hydromagnetic free convective flow past an infinite vertical, porous plate in the presence of a uniform transverse magnetic field has been considered taking Hall effects into account. Approximate solutions for the mean velocity, mean temperature and their related quantities are obtained. The influence of various dimensionless parameters is discussed

Certain vacuum Bianchi-type models in a new relativistic theory of gravitation

The vacuum Bianchi type-I, III, V, VI0 and Kantowski-Sachs models have been obtained in a new scalar-tensor theory formulated by Lau and Prokhovnik (1986) under the assumption of a certain relationship between the cosmological term Λ and the scalar field ψ. The dynamical behaviour of these models have been studied.

Bianchi type II, VIII, and IX cosmological models in Lyra's geometry

The Bianchi type II, VIII, and IX models are investigated in Lyras geometry (in normal gauge) when the gauge functionβ is time dependent. The physical behavior of these models in vacuum and in the presence of the Zeldovich fluid is discussed.

Unsteady free-convective flow and mass transfer in a rotating porous medium with Hall current, I

The Hall effect on the unsteady hydromagnetic free-convection resulting from the combined effects of thermal and mass diffusion of an electrical-conducting liquid through a porous medium past an infinite vertical porous plate in a rotating system have been analysed. The expressions for the mean velocity, mean skin friction, and mean rate of heat transfer on the plate are derived. The effects of magnetic parameterM, Hall parameterm, Ekman numberE, and permeability parameterK* on the flow field are discussed with the help of graphs and tables.

HYDROMAGNETIC EKMAN LAYER ON FREE CONVECTION PAST AN INFINITE POROUS FLAT PLATE

Free convection in a conducting liquid past an infinite porous vertical flat plate in a rotating frame of reference when the Hall current is present is considered. Exact solutions for the velocity and temperature fields have been derived. The effects ofM (Hartmann number),m (Hall parameter), andE (Ekman number) on the velocity field are discussed.

Bianchi-type cosmological models in Lyra’s geometry with constant deceleration parameter

SummaryThe Bianchi-type cosmological models have been studied in Lyra’s geometry for a law of variation of Hubble’s parameter presented by Berman (1983) that yields constant deceleration parameter models of the universe. All the models have a singular origin (t = 0) and evolve with time. The gauge function \(t) is an arbitrary function of time.