We analyze the application to elastodynamic problems of mixed finite element methods for elasticity with weakly imposed symmetry of stress. Our approach leads to a semidiscrete method which consists of a system of ordinary differential equations without algebraic constraints. Our error analysis, which is based on a new elliptic projection operator, applies to several mixed finite element spaces...

We prove a posteriori error estimates for a nite element method for steady-state, energy dependent, Fokker-Planck and Fermi pencil beam equations in two space dimensions and with a forward-peaked scattering (i.e., with velocities varying within the right unit semicircle). Our estimates are based on a transversal symmetry assumption, together with a strong stability estimate for an associated du...

This chapter examines the effects of femoral neck geometry and topological structure on elastic properties. A finite element code is used to calculate the full elastic tensor for thirteen human proximal femur specimens. We show that the micro-structure within the human femoral neck and head gives rise to approximate orthotropic elastic symmetry at the whole bone scale. The finite element code c...

The theory of elasticity is used to predict the response of a material body subject to applied forces. In the linear theory, where the displacement is small, the stress tensor which measures the internal forces is the variable of primal importance. However the symmetry of the stress tensor which expresses the conservation of angular momentum had been a challenge for finite element computations....

A Z 2L × Z 2R generation symmetry in the neutrino sector predicts the atmospheric neutrino mixing to be maximal, and the MNS matrix element U e3 to be zero, consistent with observations. Solar neutrino mixing may be maximal but is not required by the symmetry. Neutrino masses of the first two generations are predicted to vanish, providing a first approximation to the oscillation data. The conse...

This article is devoted to an important problem of calculation of deflected mode of the combustion chamber and the nozzle end of a new liquid-propellant rocket cruise engine. A special attention is given to the methodology of calculation. Three operating modes are considered. The analysis has been conducted in ANSYS software. The methods of conducted research are mathematical modeling, substruc...

In this work, we provide evidence of a mechanism to reinforce the strength of an icosahedral virus by using its genomic DNA as a structural element. The mechanical properties of individual empty capsids and DNA-containing virions of the minute virus of mice are investigated by using atomic force microscopy. The stiffness of the empty capsid is found to be isotropic. Remarkably, the presence of ...

We study the solution of linear systems that typically arise in discretizations of boundary value problems on a domain with geometrical symmetries. If the discretization is done in an appropriate way, then such a system commutes with a group of permutation matrices. Recently, algorithms have been developed that exploit this special structure, however these methods are limited to the case that t...

The matrix element of the isoscalar axial vector current, ūγμγ5u+ d̄γμγ5d, between nucleon states is computed using the external field QCD sum rule method. The external field induced correlator, 〈0|q̄γμγ5q|0〉, is calculated from the spectrum of the isoscalar axial vector meson states. Since it is difficult to ascertain, from QCD sum rule for hyperons, the accuracy of validity of flavour SU(3) sym...