The effect of mechanical stress on interdiffusion in a binary substitutional solid solution has been investigated from a theoretical point of view. Fick's first law, stating that the diffusional flux is proportional to the concentration (chemical potential) gradient, is the basic equation for diffusional mass transport. Limits of its validity, in particular in a state of non-hydrostatic stress,...

We have investigated the cellular responses to hydrostatic pressure by using the fission yeast Schizosaccharomyces pombe as a model system. Exposure to sublethal levels of hydrostatic pressure resulted in G2 cell cycle delay. This delay resulted from Cdc2 tyrosine-15 (Y-15) phosphorylation, and it was abrogated by simultaneous disruption of the Cdc2 kinase regulators Cdc25 and Wee1. However, ce...

Cells of the terrestrial plant species bromegrass (Bromus inermis L.) are not naturally adapted to withstand the hydrostatic pressures encountered in aquatic environments. However, after treatment with the natural plant growth hormone abscisic acid (75 micromolar), bromegrass cells survived a hydrostatic pressure of 101.3 megapascals, approximating the limits of ocean depth (10,860 m). The incr...

In order to image the shear modulus in soft tissue, for medical diagnosis, given one component of measured displacements as a function of time on an imaging plane, two related direct finite element-based inversion algorithms are presented. One algorithm is based on the governing equations expressed in the frequency domain, and the other is in the time domain. The algorithms consider the complet...

This paper is concerned on the phase transformation mechanism of porous Shape Memory Alloys (SMAs). A unit-cell model is adopted to establish the constitutive relation for porous SMAs, the stress distributions, the phase distributions and the martensitic volume fractions for the model are then derived under both pure hydrostatic stress and uniaxial compression. Further, an example for the uniax...

Based on the results that the magnitude of the stabilization of retained austenite increases with increasing the amount of martensite transformed, it has been assumed that the martensitic transformation is accompanied with an increase in internal resisting stress which subsequently results in the stabilization of retained austenite. By simplifying this internal resisting stress to be a type of ...

Density functional theory calculations are employed to investigate the energetics of point defects—monovacancy, self-interstitials (tetrahedral, octahedral and dumbbell) and Frenkel pairs— in aluminum under tensile hydrostatic stresses. Our study suggests that the defect core-energy of a vacancy, which is governed solely by the electronic-structure at the core, significantly depends on the macr...

The hydrostatic piezoelectric properties of [011] poled Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) crystals and corresponding 2-2 crystal/epoxy composites were investigated. The crystal volume ratio and compositional dependencies of the hydrostatic charge and voltage coefficients (dh and gh ) and hydrostatic figure of merit (FOM) dh  × gh were determined, where large FOM value of 3.2 pm2/N with high stab...

It has been shown that the plastic response of many materials, including some metallic alloys, depends on the stress state. In this paper, we describe a plasticity model for isotropic materials, which is a function of the hydrostatic stress as well as the second and third invariants of the stress deviator, and present its finite element implementation, including integration of the constitutive ...

It is generally known that severe plastic deformation processes with back pressure not only apply higher hydrostatic stress and more deformation compared to what a regular process can apply to a workpiece but also prevent surface defects in the workpiece during the process. Hydrostatic cyclic expansion extrusion (HCEE) was developed recently for processing long ultrafine-grained metals and allo...