Hugoniot States and Mie–Grüneisen Equation of State of Iron Estimated Using Molecular Dynamics

The objective of this study was to develop a micromechanical approach for determining the Mie–Grüneisen EOS parameters of iron under the Hugoniot states. The multiscale shock technique (MSST) coupled with molecular dynamics (MD) simulations was employed to describe the shocked Hugoniot relation of single-crystal (SC) and nanocrystalline (NC) iron under high pressures. The Mie–Grüneisen equation of state (EOS) parameters, the cold pressure (Pc), the cold energy (Ec), the Grüneisen coefficient (γ), and the melting temperature (Tm) are discussed. The error between SC and NC iron results was found to be less than 1.5%. Interestingly, the differences in Hugoniot state (PH) and the internal energy between SC and NC iron were insignificant, which shows that the effect of grain size (GS) under high pressures was not significant. The Pc and Ec of SC and NC iron calculated based on the Morse potential were almost the same with those calculated based on the Born–Mayer potential; however, those calculated based on the Born–Mayer potential were a little larger at high pressures. In addition, several empirical and theoretical models were compared for the calculation of γ and Tm. The Mie–Grüneisen EOSs were shown on the 3D contour space; the pressure obtained with the Hugoniot curves as the reference was larger than that obtained with the cold curves as the reference.

Another Proof of Existence of Global Weak Solutions to 1D Pollutant Transport Model

This paper is devoted to the study of pollutant transport model by water in dimension one. The model studied extend the results obtained in ( Roamba, Zabsonré & Zongo, 2017) . However, our model does not take into account cold pressure term and the quadratic friction term as in (Roamba, Zabsonré & Zongo, 2017) which are considered regularizing terms to show the existence of global weak solutions of your model. Without these regularizing terms, we show the existence of global weak solutions in time with a periodic domain.

Existence of global weak solution for quantum Navier–Stokes system

In this paper, the barotropic compressible quantum Navier–Stokes equations with a density-dependent viscosity in a three-dimensional torus is studied. By introducing a cold pressure to handle the convection term, we prove the global-in-time existence of weak solutions to quantum Navier–Stokes equations for large data in the sense of standard definition.

Laser Surface Treatment Effect on Structural Properties for Invar Alloy Type Prepared by Powder Technology

This research aimed to prepare iron-nickel alloys via powder technology, because this technology has its physical and commercial importance. Fe and Ni powders were blended into a mixture that was 63% Fe and 37% Ni and then compacted under 6 tons of isostatic cold pressure. Iron and nickel powders were used as tacking mixed together (63% of iron and 37% of nickel), and then compacted isostatic cold pressure at 6 tons. Laser surface treatment was done to samples with different energies (0, 200, 260, and 300 mJ) at a pulse time of 10 seconds and a distance of 100 cm. The x-ray diffraction test indicated that all samples had face-centered cubic, and according to the Debye-Scherrer equation. the 300 mJ sample had the best properties, including increased phase intensity and decreased grain size. The atomic force microsope showed that increasing laser energy also decreased grain size and increased surface softness and homogeneity. laser treatment results indicated an improved in structural properties with increased laser energy, Laser analysis revealed that melting all surface molecules improved structural properties. Specifically, the last treatment (300 mJ) acheaved the best structural properties of the alloy.

Evolution of acid nociception: ion channels and receptors for detecting acid

Nociceptors, i.e. sensory neurons tuned to detect noxious stimuli, are found in numerous phyla of the Animalia kingdom and are often polymodal, responding to a variety of stimuli, e.g. heat, cold, pressure and chemicals, such as acid. Owing to the ability of protons to have a profound effect on ionic homeostasis and damage macromolecular structures, it is no wonder that the ability to detect acid is conserved across many species. To detect changes in pH, nociceptors are equipped with an assortment of different acid sensors, some of which can detect mild changes in pH, such as the acid-sensing ion channels, proton-sensing G protein-coupled receptors and several two-pore potassium channels, whereas others, such as the transient receptor potential vanilloid 1 ion channel, require larger shifts in pH. This review will discuss the evolution of acid sensation and the different mechanisms by which nociceptors can detect acid. This article is part of the Theo Murphy meeting issue ‘Evolution of mechanisms and behaviour important for pain’.