The parameter changes resulting from a combination of Lorentz transformation are shown to form vector field flows. The exact, finite Thomas rotation angle is determined and interpreted intuitively. Using phase portraits, the parameters evolution can be clearly visualized. In addition to identifying the fixed points, we obtain an analytic invariant, which correlates the evolution of parameters. ...

the objective of this study was to develop a numerical model for the prediction of temperature distribution, effective plastic strain distribution, and especially material flow in friction stir welding of copper plates. the deform-3d software was used by incorporating a lagrangian incremental formulation. threedimensional results of the material flow pattern which were extracted using the point...

in the present work, the effect of fluid’s elasticity was investigated on the hydrodynamic instability of blasius flow. to determine the critical reynolds number as a function of the elasticity number, a two-dimensional linear temporal stability analysis was invoked. the viscoelastic fluid is assumed to obey the walters’ b fluid model for which base flow velocity profiles were fortunately avail...

A framework for development of constitutive models based on semi-micromechanical aspects of plasticity is proposed. The resulting of this model for material employed friction type failure criterion, sub-loading surface, and associated flow rule. This model is capable of predicting effects of the rotation of principal stress/strain axes and consequent plastic flow, induced anisotropy of strength...

Background and Aim: This study assessed the salivary calcium level, salivary flow rate, and dental problems of patients with Sjogren’s syndrome. Materials and Methods: This case-control study was conducted on 30 patients with Sjogren’s syndrome and 30 healthy controls. The salivary flow rate, salivary calcium level, and the decayed, missing, and filled surfaces (DMFS) index were recorded. ...

exergy analysis of a system is a method for recognizing the value and type of system availability against surrounding environment. it also helps to find how macroscopic properties of the system change during a process. this analysis is based on first and second laws of thermodynamics. by exergy analysis proportion of each process in the internal availability transmission and the places of usefu...

the aim of this work is to describe the qualitative behavior of the solution set of a givensystem of fractional differential equations and limiting behavior of the dynamical system or flow defined by the system of fractional differential equations. in order to achieve this goal, it is first necessary to develop the local theory for fractional nonlinear systems. this is done by the extension of ...

 Abstract : The meshless local Petrov-Galerkin method with unity as the weighting function has been applied to the solution of the Navier-Stokes and energy equations. The Navier-Stokes equations in terms of the stream function and vorticity formulation together with the energy equation are solved for a driven cavity flow for moderate Reynolds numbers using different point distributions. The L2-...