Monodisperse single-crystal hollow cerium dioxide nanocubes with exposed (001) facets have been synthesized with the assistance of ammonium chloride (NH4Cl) and polyvinylpyrrolidone (PVP) in a water and ethanol system. A series of experiments indicate that ammonium ion plays an important role in the formation of the hollow structure and PVP plays a key role in the formation of a cubic shape. Th...

poly(styrene-co-butyl acrylate)/clay nanocomposites were synthesized via in situ atom transfer radical polymerization using activators generated by electron transfer in the presence of a montmorillonite ion-exchanged with mixed surfactants of dodecyl trimethyl ammonium bromide and vinyl trimethyl ammonium chloride. the living nature of polymerization is confrmed by occurrence of narrow molecula...

lipases are diversified enzymes in their properties and substrate specificity, which make them attractive tools for various industrial applications. in this study, an alkaline thermostable lipase producing bacteria were isolated from soil of different regions of isfahan province (iran) and its lipase was purified by ammonium sulfate precipitation and ion exchange chromatography. to select a the...

Stable flies are blood feeding parasites and serious pests of livestock. The immature stages develop in decaying materials which frequently have high ammonium content. We added various ammonium salts to our laboratory stable fly rearing medium and measured their effect on size and survival as well as the physical properties of the used media. The addition of ammonium hydroxide, ammonium phospha...

background: the compositions of ferrous sulphate, agarose and xylenol orange dye (fax) and ferrous sulphate, gelatin and xylenol orange dye (fgx) in solution of distilled water and sulphuric acid are two tissue-equivalent gel dosimeters. ionizing radiation causes oxidation of fe2+ ion to fe3+ ions which diffuse through the gel matrix and blur the image of absorbed dose over a period of hours af...

In this research, a Dispersive Liquid-Liquid MicroExtraction (DLLME) method coupled to UV-vis spectrophotometry was developed for the indirect determination of silver ion. The method is based on the catalytic effect of the silver ion on the oxidation of congo red by potassium peroxodisulphate and extraction with DLLME procedure using chloroform (extraction solvent) containing cetyltrimethyl...

The increase in proline induced by ABA, a process stimulated by NaCl or KCl in barley leaves, did not occur when Na(+) (or K(+)) was present in the external medium as the gluconate salt, namely with an anion unable to permeate the plasma membrane. However, proline increase was restored, to different extents, by the addition of various chloride salts but not by ammonium chloride. Moreover, it wa...

The fate of bacteria in human urine was studied after inoculation of small numbers of Escherichia coli and other bacterial strains commonly implicated in urinary tract infection. Urine from normal individuals was often inhibitory and sometimes bactericidal for growth of these organisms. Antibacterial activity of urine was not related to lack of nutrient material as addition of broth did not dec...

Two variant manifolds of a flow injection analysis (FIA) system are described for the determination of urea content in milks. This determination consists of the enzymatic reaction of urea with urease in which ammonium ion is formed. Ammonium is converted to ammonia by adding a NaOH solution and then led to a gas diffusion unit in which it diffuses to an acceptor channel (Tris/HCl, pH 7.5). Here...