conclusions the present research demonstrated that the ultrasonic (us) process can be utilized as an effective and simple method for treatment of mg dye in an aqueous solution. moreover, the eeo is directly proportional to the mg concentration and power density and inversely proportional to temperature and mechanical agitation, which can be predicted by the obtained empirical kinetics model. co...

Dehydration of methanol to dimethyl ether (DME) over a commercial Al2O3 catalyst was studied in an isothermal integral fixed bed reactor. The experiments were performed on the temperature interval 513-613 K, liquid hourly space velocity (LHSV) of 0.9-2.1h, pressures between 0.1 and 1.0 MPa. The effect of different operation conditions on the dehydration of methanol was investigated in a laborat...

Fast self sustained waves of chemical or phase transformations, observed in several contexts in condensed matter effectively result in “gasless detonation”. The phenomenon is modelled by coupling the reaction diffusion equation, describing chemical or phase transformations, and the wave equation, describing elastic perturbations. The coupling considered in this work involves (i) a dependence of...

In microbial competition theory, the Michaelis-Menten (MM) half-saturation coefficient is often considered to be a trait of an organism defining competitive strength in a trade-off conflict with maximum uptake rate. Theoretical studies have shown that a quadratic model characterizes the uptake rate, and that this model can be approximated by a MM model. Here, we review recent developments in nu...

Oral dosage forms containing 300 mg theophylline in matrix type tablets, were prepared by direct compression method using two kinds of matrices, glycerylbehenate (hydrophobic), and (hydroxypropyl)methyl cellulose (hydrophilic). The in vitro release kinetics of these formulations were studied at pH 6.8 using the USP dissolution apparatus with the paddle assemble. The kinetics of the dissolution ...

Oral dosage forms containing 300 mg theophylline in matrix-type tablets were prepared by direct compression method using two kinds of matrices – glycerylbehenate (hydrophobic) and hydroxypropylmethyl cellulose (hydrophilic). The in vitro release kinetics of these formulations were studied at pH 6.8 using the USP dissolution apparatus with the paddle assemble. The kinetics of the dissolution pro...

In this work dynamic recrystallization behavior of AISI 403 martensitic stainless steel was studied using hot compression tests over temperature range of 900 C -1200 C and strain rate range of 0.001 s-1 - 1 s-1. The obtained flow curves showed that the hot compression behavior of the alloy is controlled by dynamic recrystallization. The flow stress and strain corresponding to the critical, pe...

This paper applies a statistical thermodynamic approach to the kinetics of microbial growth influenced by pH. A general equation is developed and shown to provide a good theoretical basis for the existing pH models that have been widely used to describe the effects of pH on microbial growth kinetics. Four experimental data sets are used to test the general equation developed. The four data sets...

Dynamical processes exhibiting non-Poissonian kinetics with nonexponential waiting times are frequently encountered in nature. Examples are biochemical processes like gene transcription which are known to involve multiple intermediate steps. However, often a second process, obeying Poissonian statistics, affects the first one simultaneously, such as the degradation of mRNA in the above example....

The fermentation kinetics of L-glutamic acid by Corynebacterium glutamicum was studied in a batch bioreactor. Mathematical model using the logistic equation for growth, Leudeking-Piret kinetic equation for product formation and Leudeking-Piret like equation for substrate consumption was proposed. Based on the analysis of experimental data followed by computer simulation, the model seemed to pro...