Electrical conductivity characterized at varying strains in spiral cut high-pressure torsion discs

Thermal conductivity reduction of crystalline silicon by high-pressure torsion

We report a dramatic and irreversible reduction in the lattice thermal conductivity of bulk crystalline silicon when subjected to intense plastic strain under a pressure of 24 GPa using high-pressure torsion (HPT). Thermal conductivity of the HPT-processed samples were measured using picosecond time domain thermoreflectance. Thermal conductivity measurements show that the HPT-processed samples ...

Electrical conductivity of wadsleyite at high temperatures and high pressures

Numerical Analysis of Severe Plastic Deformation by High Pressure Torsion

High-pressure torsion (HPT) is a metal processing method in which the sample is subjected to a very high plastic shear deformation. This process can produce exceptional levels of grain refinement, and provides a corresponding improvement in mechanical properties. To investigate the stress and strain distribution due to HPT process finite element simulation were conducted to investigate effectiv...

Spiral waves in accretion discs

In the first part of this article, we review the observational evidence for spirals in the accretion discs of cataclysmic variables. It is shown that with the increasing amount of data available, spirals appear to be an omnipresent feature of accretion discs in outburst. Spirals seem to live until decline that is, for several tens of orbital periods. We then study the formation of spiral shocks...

High pressure high temperature cell for electrical conductivity measurements of Earth-type materials

AbstructA high pressure, high temperature cell has been constructed and used to determine the temperature dependence of the electrical conductivity of various geological materials at a frequency of 60 Hz. Test conditions in the cell approximate an in situ environment by means of a variable uniaxial confining pressure and a separately variable pore pressure. A wide array of constituents of typic...