ticl4, ammonia, inorganic salts as raw material, nanometer composite-crystal tio2 powders were synthesized by two-step chemical method. precursors were crystallized with different phase and stable composite-crystal tio2 with anatase and rutile phase was prepared at low temperature. quantitative control of crystal phase was realized. remarkable factors including reaction ph value, reaction time,...

Esterification of chitosan with adipic acid catalyzed by immobilized Candida antarctica lipase B was carried out in this study. Response surface methodology (RSM) based on a four-factor- five-level small central composite design (SCCD) was employed to model and analyze the reaction. A total of 21 experiments representing different combinations of the four reaction parameters including ch...

In the present work, we have synthesizedgadolinium(III) bromide, GdBr3 from the gadolinium oxide, Gd2O3 by sintering brominating with ammonium bromide, NH4Br. The influence of three main synthesis parameters (contact time, stoichiometry, and temperature) on the reaction yield was studied and optimized. This study showed that the optimum conditions...

results our study showed that the sensitivity and specificity of taqman real time pcr was 96% and 95% respectively. these values were 89% and 90, 38% and 100%, 6% and 100% for pcr, culture and microscopy, respectively. conclusions our study showed that sensitivity of taqman real time pcr was higher that pcr, culture and microscopy but specificity of culture and microscopy was more than pcr and ...

Abstract: the reduction agent. Pellets of barite ore containing about 95% BaSOtemperature, time, ore grain size and the type and grain size of the carbon materials. Graphite, coke and charcoal havebeen used as the reducing agent and the reduction experiments have been performed in the temperature range of 925-1150 °C. Apart from conducting the experiments using pellets made of ore powder, kinet...

background: high concentration of salt makes biological treatment impossible due to bacterial plasmolysis. the present research studies the process of electrochemical oxidation efficiency and optimal levels as important factors affecting ph, salt concentration, reaction time and applied voltage. methods: the sample included graphite electrodes with specifications of 2.5 cm diameter and 15 cm he...

Nowadays, numerical models have great importance in every field of science, especially for solving the nonlinear differential equations, partial differential equations, biochemical reactions, etc. The total time evolution of the reactant concentrations in the basic enzyme-substrate reaction is simulated by the Runge-Kutta of order four (RK4) and by nonstandard finite difference (NSFD) method. A...

TiCl4, ammonia, inorganic salts as raw material, nanometer composite-crystal TiO2 powders were synthesized by two-step chemical method. Precursors were crystallized with different phase and stable composite-crystal TiO2 with anatase and rutile phase was prepared at low temperature. Quantitative control of crystal phase was realized. Remarkable factors includ...