344 research outputs found
Asymptotic symmetry and conservation laws in 2d Poincar\'e gauge theory of gravity
The structure of the asymptotic symmetry in the Poincar\'e gauge theory of
gravity in 2d is clarified by using the Hamiltonian formalism. The improved
form of the generator of the asymptotic symmetry is found for very general
asymptotic behaviour of phase space variables, and the related conserved
quantities are explicitly constructed.Comment: 22 pages, Plain Te
MHD flow and heat transfer of two immiscible fluids between moving plates
The magnetohydrodynamic (MHD) flow of two immiscible and electrically conducting fluids between isothermal, insulated moving plates in the presence of an applied electric and inclined magnetic field has been investigated in the paper. The partial differential equations governing the flow and heat transfer are solved analytically with appropriate boundary conditions for each fluid and these solutions have been matched at the interface. The numerical results for various values of the Hartmann number, the angle of magnetic field inclination, load parameter and the ratio of electrical and thermal conductivities have been presented graphically. It was found that decrease of magnetic field inclination angle flattens out the velocity and temperature profiles. With the increase of the Hartmann number velocity gradients near the plate's increases, temperature in the middle of the channel decreases and near the plate's increases. Induced magnetic field is evidently suppressed with an increase of the Hartman number. The effect of changes of the load factor is to aid or oppose the flow as compared to the short-circuited case
THE BEHAVIOUR OF MUSCLES IN EXTERNAL INSTANTANEOUS FORCE FIELDS
The purpose of this study is to analyze the behaviour of muscles in an external instantaneous force field. A model is presented which provides a qualitative assessment of what occurs when muscles react to a strong strike or a sudden jerk.
In the context of the model, it has been noticed that fine muscles reacted to a strike or jerk differently to massive muscles
THE MUSCLE CONTRACTION AND THE FORCE PRODUCTION
We study the muscular force during contraction via linear and quadratic approximations of the resistance force. Using theoretical - mechanics arguments, we shall determine the relevant parameters featuring in the equation of motion. This is very important for the determination of the type of training practice which will transform the muscle for various types of dealing with the medium resistance
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