This thesis explores the potential of zinc, cobalt, and phosphorus to influence primary production in the subarctic North Pacific, the Bering Sea, and the North Atlantic Ocean. In the North Pacific and Bering Sea, total zinc concentrations were measured along a near-surface transect and in selected deep profiles. Zinc speciation was also measured with a novel anodic stripping voltammetry method...

several factors effect on sorption of polycyclic aromatic hydrocarbons (pahs) in soil. co-existence of metals and organic matter of soil are among important affecting factors on sorptive behavior of pahs. this research investigated the effect of organic matter content and heavy metals (lead, nickel and zinc), on sorption of phenanthrene onto kaolinite. for this purpose, sorption of the organic ...

introduction: gutta-percha, the concrete milky juice of the sapotaceae family tree, is the most commonly used material for obturation of prepared canal space. natural 1-4 trans stereochemical structure of gutta-percha is taken to a heating- inclusion process of various organic and inorganic elements by manufacturers. the purpose of this study is to detect the presence and percentage of inorgani...

[equation: see text] An efficient one-pot route to unsymmetrical diorganyl selenides has been developed by ruthenium(III) chloride catalyzed reactions of dibenzyl or diphenyl diselenides with alkyl halides in the presence of zinc. Organic iodides, bromides, and activated chlorides underwent the reactions efficiently. Unreactive organic chlorides also underwent the same type of selenation with s...

in recent years, zinc oxid nanotubes have attracted much attention. the direct use of , zinc oxidnanotubes modified by sio2 as recoverable catalysts for organic reactions is very rare. the catalystswere characterized by xrd. the average particle size of zno catalysts is 57 nm and there are highdensitydefects on nanotubes surfaces . a simple and efficient method for the imidazol derivativessynth...

Direct heating of a metal-organic framework provides a simple, controllable way of effecting a covalent post-synthetic modification. Herein we report that an allyloxy-tagged zinc metal-organic framework undergoes a thermally-promoted aromatic Claisen rearrangement through which the framework connectivity and porosity are maintained.

Phosphate plays a key role in regulating primary productivity in several regions of the world's oceans and here dissolved organic phosphate can be an important phosphate source. A key enzyme for utilizing dissolved organic phosphate is alkaline phosphatase and the phoA-type of this enzyme has a zinc cofactor. As the dissolved zinc concentration is low in phosphate depleted environments, this ha...

a greenhouse experiment was conducted using completely randomised design (factorial) with three replications to study the residual effect of organic manures (municipal solid waste compost and cow manure), zinc (0 and 50 kgha-1) and boron (0 and 10 kg.ha-1) by using znso4 and h3bo3 salts respectively, (applied earlier for millet (panicum italicum l.) crop) on soil properties and chemical composi...

a r t i c l e i n f o Thin-films and organic field-effect transistors fabricated from a solution-processable precursor of zinc tetra-benzoporphyrin (ZnTBP) are reported. Amorphous, insulating precursor films were deposited by spin-casting and thermally converted into polycrystalline, semiconducting thin-films comprising grains on the order of 5 μm in diameter. Thin-film X-ray diffraction indica...

The aims of this study were to investigate zinc content in the studied soils; evaluate the efficiency of geostatistics in presenting spatial variability of zinc in the soils; assess bioavailable forms of zinc in the soils and to assess soil-zinc binding ability; and to estimate the potential ecological risk of zinc in soils. The study was conducted in southern Poland, in the Malopolska Province...