Topic
Ammonia
About: Ammonia is a research topic. Over the lifetime, 16217 publications have been published within this topic receiving 271940 citations. The topic is also known as: NH3 & azane.
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TL;DR: In this paper, the authors compared the performance of promoted and unpromoted Ru/Al2O3 catalysts around 588 K. They found that the promotion by Sm2O 3 was mainly due to hydrogen release, which might be related with the morphological modification of Ru by nascent Sm 2O 3.
95 citations
TL;DR: A procedure has been developed for the measurement of cathepsin B2 activity that is based upon highly sensitive fluorometric ammonia analysis, which means that the awkward diffusion step of most routine ammonia analyses can be eliminated.
95 citations
TL;DR: Ammonia at concentrations above 1×10-5 M inhibits uptake of nitrate in the nitrogen-fixing blue-green alga, Anabaena cylindrica, both in the light and in the dark.
Abstract: Ammonia at concentrations above 1×10-5 M inhibits uptake of nitrate in the nitrogen-fixing blue-green alga, Anabaena cylindrica. This inhibition takes place both in the light and in the dark. The rate of nitrate uptake is stimulated by light. Addition of relatively high concentrations of nitrate (1–10 mM) reversibly inhibits ammonia uptake. FCCP, an uncoupler of phosphorylation, inhibits both nitrate and ammonia uptake. Ammonia may inhibit nitrate uptake by reducing the supply of energy (ATP) for active nitrate transport.
94 citations
TL;DR: In this article, a modified Mn-Ce/γ-Al 2 O 3 granular catalyst was modified by adding silver and then developed in the low temperature selective catalytic reduction (SCR) of NO with NH 3.
94 citations
TL;DR: Ammonia and labile amino nitrogen were measured as one nitrogen fraction in one offshore water mass northwest of the Costa Rica Dome as discussed by the authors, and the ammonia concentration was greater than that of nitrate and the N : P ratio was increased threefold to fourfold if ammonia was included with nitrate.
Abstract: Mean surface concentrations of nitrogenous nutrients and phosphate are reported for various areas in the northcastcrn tropical Pacific Ocean. Except at the Costa Rica Dome, an area of upwelling, nitrate concentrations were very low. NOs: Poe’ratios were also generally low and phytoplankton might remove all of the nitrate while appreciable concentrations of phosphate were still present. Measurements of nitrate during growth of batch cultures of Gymnodinium simplex showed that concentrations below approximately 5 pg-at./ liter probably limited the rate of growth of this dinoflagellate. Since surface nitrate concentrations were generally lower than this value, the rate of growth of G. simplex would be limited over much of the arca, unless sources of nitrogen other than nitrate were available. Ammonia and labile amino nitrogen were measured as one nitrogen fraction in one offshore water mass northwest of the Dome. The ammonia concentration was greater than that of nitrate and the N : P ratio was increased threefold to fourfold if ammonia was included with nitrate, The growth of three phytoplankton cultures was supported by ammonia and by various amino compounds. Ammonia may be a relatively important nitrogen source in the northeastern tropical Pacific Ocean, and should be included with nitrate as a measure of the total nitrogen available to phytoplankton. Ammonia may moderate the extreme nitrogen deficiency which would be expected if nitrate were considered the only source of nitrogen.
94 citations