The first considered problem is the problem of arising dynamic dissipative structures in the chemical reactor volume. The mathematical model of heat and mass transfer in the tubular through-reactors has been submitted. The model consists of the diffusion-kinetic equations for two reagents under the first-order reversible reaction and heat transfer equation with allowance for the latent heat of ...

We grew SrTiO3 on SrTiO3(001) by pulsed laser deposition, using x-ray scattering to monitor the growth in real time. The time-resolved small-angle scattering exhibits a well-defined length scale associated with the spacing between unit-cell high surface features. This length scale imposes a discrete spectrum of Fourier components and rate constants upon the diffusion equation solution, evident ...

We propose a rate process model for describing photochemical damage to retinal cells by short wavelength laser exposures. The rate equation for photochemical damage contains a positive rate that is temperature independent, and a negative (quenching) rate that is temperature dependent. Using the traditional Arrhenius integral to describe thermal damage, we derive damage threshold doses for both ...

This article is devoted to the explanation of the onset of localization and the formation of shear bands in high strain-rate plasticity of metals. We employ the Arrhenius constitutive model and show Hadamard instability for the linearized problem. For the nonlinear model, using an asymptotic procedure motivated by the theory of relaxation and the Chapman-Enskog expansion, we derive an effective...

The dynamics of two 12-monomer heteropolymers on the square lattice is studied exactly within the master equation approach. The time evolution of the occupancy of the native state is determined. At low temperatures, the median folding time follows the Arrhenius law and is governed by the longest relaxation time. For both good and bad folders, significant kinetic traps appear in the folding funn...

On short time scales an underlying Arrhenius temperature dependence of the diffusion constant can be extracted from the fragile, super-Arrhenius diffusion of a binary Lennard-Jones mixture. This Arrhenius diffusion is related to the true super-Arrhenius behavior by a factor that depends on the average angle between steps in successive time windows. The correction factor accounts for the fact th...

The purpose of this study was to predict the stability of octreotide in a mixed infusion containing sodium bisulfite (SBS). In aqueous solution the hydrolysis of octreotide was found to be accelerated by pH, and by increasing concentrations of SBS. Equations for the degradation rate constants (kobs) of pH and SBS were derived. The fractional rate constants were estimated by the nonlinear least-...

The influence of calcination time on the phase transformation and crystallization kinetics of anodized titania nanotube arrays was studied using in-situ isothermal and non-isothermal synchrotron radiation diffraction from room temperature to 900 °C. Anatase first crystallized at 400 °C, while rutile crystallized at 550 °C. Isothermal heating of the anodized titania nanotubes by an increase in t...

Based on measurements of the dynamic viscosity, a strategy is proposed to find an expression that relates the viscosity of an epoxy compound during curing, to the temperature, shear rate, and degree of reaction. It appeared that the dynamic viscosity is a unique function of the effective shear rate (i.e. the product of frequency and strain) over a wide range of frequencies and strains after bei...

The nitrogen-containing austenitic stainless steel 316LN has been chosen as the material for nuclear main-pipe, which is one of the key parts in 3rd generation nuclear power plants. In this research, a constitutive model of nitrogen-containing austenitic stainless steel is developed. The true stress-true strain curves obtained from isothermal hot compression tests over a wide range of temperatu...