A semiempirical interatomic potential for Fe was used to calculate the diffusivity in bcc Fe assuming the vacancy and interstitial mechanisms of self-diffusion. Point-defect concentrations and diffusivities were obtained directly from molecular dynamics MD simulations. It was found that self-diffusion in bcc Fe is controlled by the vacancy mechanism at all temperatures. This result is due to th...

nano-zno was employed for the adsorption of 4c2np from aqueous solutions in batch equilibriumexperiments to investigate its adsorption properties. the quantity of 4c2np adsorbed onto nano- znosurface was measured by uv-vis spectrophotometer. the effects of contact time, adsorbent dose, ph, andinitial concentration of 4c2np were investigated. the adsorption found to be strongly influenced by all...

abstract herbicides are the main sources of soil and water pollution in paddy fields. herbicides mobility to the surface and ground water is a major concern for human health and the environment. it is, therefore, necessary to investigate their fate and their interactions in natural ecosystems. to meet this purpose, field experiments were conducted to measure kinetic of thiobencarb dissipation i...

It has long been hypothesised that futile cycles in cellular metabolism are involved in the regulation of biochemical pathways. Following the work of Newsholme and Crabtree, a quantitative theory was developed for this idea based on open-system thermodynamics and metabolic control analysis. It is shown that the stoichiometric sensitivity of an intermediary metabolite concentration with respect ...

The paper is dedicated to the description of the algorithm of calculation of the equilibrium gas-phase concentration at the surface of the aerosol particle – a parameter, which defines the rate of mass transport between the gas and aerosol phases in the kinetic models of atmospheric aerosol dynamics. Some problems concerning deducing of the surface equilibrium gasphase concentrations from therm...

We succeeded in simulating the many-particle A ‡ B 6 C reaction in three-dimensions to suciently long-times, revealing the ultimate asymptotic approach to equilibrium. The deviation from equilibrium is a t À3=2 power-law, with a concentration-dependent prefactor which agrees quantitatively with the theoretical prediction. The logarithmic derivative of the deviation from equilibrium undergoes t...

adsorption and water treatment of ca (ii) and mg (ii) hardness were investigated via adsorption of metal ions onto commercial polyacrylic acid hydrogel beads as a novel sorbent for metal ions (ca2+, mg2+) removal and water treatment. batch equilibrium technique was carried out under the influence of solution ph, contact time, sorbent dosage, initial metal concentration and competitive study. th...

Mass transfer during membrane formation by means of phase inversion for a polymeric system with both a solid-liquid and a liquid-liquid equilibrium was studied on the basis of the theory developed by Reuvers and Smolders. During the first moments of immersion in the coagulation bath, the concentrations at the interface between bath and film are governed by the virtual liquid-liquid equilibrium....

The movement of water and chemicals in soils is generally better described with multidimensional nonequilibrium models than with more commonly used one-dimensional and/or equilibrium models. This paper presents analytical solutions for non-equilibrium solute transport in semi-infinite porous media during steady unidirectional flow. The solutions can be used to model transport in porous media wh...

Hydrogen (H2) is an essential substrate for methanogens to produce methane (CH4), and also influences pathways of volatile fatty acids (VFA) production in the rumen. Dissolved H2 (H2 (aq)) is the form of H2 available to microbes, and dissolved CH4 (CH4 (aq)) is important for indicating methanogens activity. Rumen H2 (aq) concentration has been estimated by assuming equilibrium with headspace ga...