nickel (ni) is one of the essential micronutrients for higher plants and its known function is beingthe metal component of urease. the effects of various ni levels on urease activity in maize (zea maize l.)plants grown in two nutrient media containing urea or ammonium nitrate as two separate nitrogen sourceswere investigated. the experiments were performed as completely randomized blocks with t...

simple, cheap and green protocol for effective conversion of alcohols to corresponding carbonyl compounds in the presence of h14[nap5w30o110] and ammonium nitrate is reported. the products were characterized by ft-ir and comparison of their physical properties with those reported in the literatures. the progress of the reaction was monitored by thin layer chromatography (tlc) technique. the ali...

abstract nitrogen is a key nutrient in plant growth and it is necessary for amino acid synthesis. sulfur has very important role in the biosynthesis of the alliums flavor and pungency precursors and potassium improve crop yield and quality. in order to study the effect of ammonium nitrate and potassium sulfate on concentration some of the mineral elements in onion (allium cepa l. azar shahr cv....

mapping of groundwater nitrate can be useful in management of groundwater resources. the objectives of this study were to analyze the spatial variability of nitrate and to map its contamination in the lordegan aquifer and to evaluate the variations in nitrate variability and mapping during a year. then 32 wells were sampled four times during 2010. seasonal nitrate concentrations remained consta...

Atrazine, metolachlor, carbaryl, and chlorothalonil are detected in streams throughout the U.S. at concentrations that may have adverse effects on benthic microbes. Sediment samples were exposed to these pesticides to quantify responses of ammonium, nitrate, and phosphate uptake by the benthic microbial community. Control uptake rates of sediments had net remineralization of nitrate (-1.58 NO3 ...

Plants take up inorganic nitrogen (N) primarily as nitrate but also to a lesser extent as ammonium. Nitrate is reduced to nitrite in the cytoplasm by the highly regulated enzyme nitrate reductase. Nitrite is transported into the chloroplast and further reduced by nitrite reductase to ammonium. Ammonium is assimilated into the amino acid pool by the coordinate action of Gln synthetase (GS) and G...

The development of titrimetric sensor applications to monitor biological wastewater treatment processes is shortly described, and the measurement principle (based on a pH controller) is illustrated. 3 applications that were developed during the past years are used to illustrate the capabilities of titrimetric sensors. The ammonium and the nitrate concentration can be measured to monitor the nit...

Excised 7-day-old oat (Avena sativa L. cv. Jaycee) leaves were incubated in media containing 7.1 millimolar KNO(3) and 0.15 millimolar tabtoxin or 1 millimolar methionine sulfoximine (MSO) to investigate the sources of the observed ammonium accumulated. Tabtoxin and MSO are known inhibitors of glutamine synthetase, the first enzyme in the primary pathway of ammonium assimilation. During a 4- to...

The specific activities of nitrate reductase, nitrite reductase, glutamine synthetase, glutamate synthase, and glutamate dehydrogenase were determined in intact protoplasts and intact chloroplasts from Chlamydomonas reinhardtii. After correction for contamination, the data were used to calculate the portion of each enzyme in the algal chloroplast. The chloroplast of C. reinhardtii contained all...