in the present investigation, dead bacterium biomass streptomyces rimosus was used as an inexpensive and efficient biosorbent for cr (iii) removal from aqueous solution. the bacterial biomass was treated with 0.1 m naoh. sorption level of 65 mg/g was observed at ph 4.8 while precipitation effect augmented this value at higher ph range. chromium desorption increased with decreasing desorption ag...

BACKGROUND Understanding the nitrogen (N) mineralization process and applying appropriate model simulation are key factors in evaluating N mineralization. However, there are few studies of the N mineralization characteristics of paddy soils in Mollisols area of Northeast China. MATERIALS AND METHODS The soils were sampled from the counties of Qingan and Huachuan, which were located in Molliso...

Bicyclic aziridines show exclusive photochromic behavior. Here, we summarize the results of optical and electrochemical properties, such as photochemical, solvatochromic, electrochromic andkinetic behavior of bicyclic aziridines linked to chalcone moieties. The photochromic process for conversion of closed photoisomers to open photoisomers for compounds 1-10 followed zero-order kinetics. For co...

The kinetics and mechanism of the reaction between benzaldehyde 1, malononitrile 2 and dimedone 3 in a mixture of ethanol and water as solvents in the presence of fructose as a biodegradable catalyst has been studied by the spectroscopic method (UV-Vis spectrophotometry method). The influence of various parameters (temperature, solvent and concentration) was studied on the reaction by means of ...

The kinetics of the oxidation of Ru (III) catalyzed oxidation of tartaric acid by potassium bromate in aqueous perchloric acid medium at constant ionic strength was investigated in the temperature range 303318 K. The reactions exhibit first order kinetics at low concentration of bromate, tending to zero order at high concentration. Zero order kinetics with respect to [tartaric acid] and first o...

The intercalation of captopril (CP) into the interlayers of montmorillonite (MMT) affords an intestine-selective drug delivery system that has a captopril-loading capacity of up to ca. 14 %w/w and which exhibits near-zero-order release kinetics.

thymol, an important and advantageous component of many essential oils, has been applied as an antimicrobial agent in animals. to increase the duration of action of this compound in ruminants, it was decided here to prepare a controlled release carrier for thymol. hydroxy propyl methyl cellulose (hpmc) and ethyl cellulose (ec) were used as the matrix polymer here. mixtures of thymol with eight ...

Nitazoxanide is a new broad-spectrum, antiparasitic drug agent. The photodegradation of nitazoxanide was studied in order to investigate the degradation kinetics of this drug. The analyses of the degraded samples were performed by a stability-indicating liquid chromatographic method. The degradation was carried out in acetonitrile with coated tablets or oral suspension powder in quartz cells un...

microwave assisted fluidized bed drying is a novel drying technique which reduces drying time and yields higher quality products. in this study the effect of this method on color changes of whole and cut hazelnut kernels was investigated. the parameters of color and resulting total color change, chroma, hue angle and browning index were also calculated during drying in three temperatures (40, 5...

it seems that the presence of soil organic matter (som) increases p availability to plants. this effect has commonly been ascribed as competition between the decomposition products of som and p for soil sorption sites resulting in p concentrations increase of soil solution. this study was carried out to obtain information about soil organic matter (som) influence on kinetics and thermodynamics ...