Weak pi hydrogen-bonded solute/solvent complexes are studied with ultrafast two-dimensional infrared (2D-IR) vibrational echo chemical exchange spectroscopy, temperature-dependent IR absorption spectroscopy, and density functional theory calculations. Eight solute/solvent complexes composed of a number of phenol derivatives and various benzene derivatives are investigated. The complexes are for...

In the present work, a synthetic effluent of phenol was treated by means of a total oxidation process—Catalyzed Wet Oxidation (CWO). A mixed oxide of Mn-Ce (7:3), the catalyst, was synthesized by co-precipitation from an aqueous solution of MnCl2 and CeCl3 in a basic medium. The mixed oxide, MnO2/CeO2, was characterized and used in the oxidation of phenol in a slurry reactor in the temperature ...

Introduction: Many kinetic studies have shown that sorption of metals on natural materials results in the formation of metal precipitates. However, the influence of temperature on the kinetic formation of these metal precipitates has not been studied. The effect of temperature on reaction rates is well known and important in understanding reaction mechanisms. For most reactions, the increase in...

The sensitivities of metallophthalocyanine (MPcs: M = Co, Ni, Cu, Zn, and H(2)) chemiresistors to vapor phase electron donors were examined using 50 nm MPc films deposited on interdigitated electrodes. Sensor responses were measured as changes in current at constant voltage. Analytes were chosen to span a broad range of Lewis base and hydrogen bond base strengths. The MPc sensor responses were ...

We investigate the escape behavior of systems governed by the one-dimensional nonlinear diffusion equation theta(t)rho=theta(x)[theta(x)Urho]+Dtheta(x)2rho(nu), where the potential of the drift, U(x), presents a double well and D,nu are real parameters. For systems close to the steady state, we obtain an analytical expression of the mean first-passage time, yielding a generalization of Arrheniu...

The flow stress and dynamic recrystallization behavior of A356 aluminum alloy was studied, with a strain rate ranging from 0.001 s?1 to 1 temperature 300 500 °C. Both the true stress–strain curves microstructure examination indicated that occurred during isothermal compression. A physical model based on Arrhenius equation developed, this can accurately predict fraction Finally, implemented in F...

1. In certain cases the rate of digestion of proteins by pepsin is not proportional to the total concentration of pepsin. 2. It is suggested that this is due to the fact that the enzyme in solution is in equilibrium with another substance (called peptone for convenience) and that the equilibrium is quantitatively expressed by the law of mass action, according to the following equation. See PDF ...

The Li⁺ diffusion coefficients in Li⁺-adsorbed graphene systems were determined by combining first-principle calculations based on density functional theory with Kinetic Monte Carlo simulations. The calculated results indicate that the interactions between Li ions have a very important influence on lithium diffusion. Based on energy barriers directly obtained from first-principle calculations f...

The deformation behavior and the constitutive description of materials are important in design numerical simulation manufacturing processes. In this work, rheological two quenchable boron steels was derived range interest for Press Hardening (PH) process. For study, following steps were performed: (i) Design specimen geometry adopted during hot tensile tests Gleeble®3180 physical simulator. (ii...

This study aims to propose a kinetics-based model of fatigue crack growth rate coupling with temperature, strain level and damage degree for bituminous materials. The length is calculated by an energy-based mechanistic (EBM) approach, kinetic parameters characterizing the are determined based on Arrhenius equation. Results show that logarithm linear inverse absolute cracking activation energy i...