نتایج جستجو برای: cobalt hydrogensulfate
تعداد نتایج: 30353 فیلتر نتایج به سال:
the structural and electrical properties of polyaniline-cobalt sulphate nanocomposite prepared by chemical method.polyaniline-cobalt sulphate nanocomposites were synthesized by the cobalt sulphate and ammonium persulphate and aniline.this paper reports on chemical technique using for synthesis of cobalt nanoparticles in the composite bridge is aniline. electrical conductivity of polyaniline wit...
A simple and mild method for tetrahydropyranylation of alcohols is reported at room temperature using a catalytic amount of 3-methylimidazolinium hydrogensulfate([Hmim]HSO4) as a green, efficient and reusable catalyst. Using solvent-free conditions, non-toxic and inexpensive materials, modest and clean work-up, short reaction times and high yields of the products are the advantages o...
In this research, we have developed cheap recyclable and task-specific acidic ionic liquids (AILs) 1-hydrogen-3-methylimidazolium hydrogen sulfate [Hmim]HSO4, 1-hydrogen-3-methylimidazolium chloride [Hmim]Cl, 2-pyrrolidonium hydrogensulfate [Hnhp]HSO4 and applied them in acid catalyzed synthesis of quinoxaline derivatives from 1,2-phenylendiamines and 1,2-dicarbonyl compounds. The products coul...
an extensive study of fischer-tropsch synthesis (fts) on alumina-supported cobalt catalysts with different amounts of cobalt is reported. up to 40 wt % of cobalt, is added to the catalysts by impregnation method. the effect of the cobalt loading on the reducibility of the cobalt oxide species, dispersion of the cobalt, average clusters size, water-gas shift (wgs) activity and activity and selec...
BACKGROUND Cobalt has been shown to induce mainly asthma, allergic contact dermatitis and hard metal disease. The data on cobalt asthma are mainly based on case reports. AIMS To characterize all the cases of occupational cobalt asthma encountered in a cobalt plant at the time of diagnosis and 6 months later. We also evaluated the incidence of cobalt asthma in different departments on the basi...
A cobalt spot test was recently developed (1). Testing for cobalt release is performed by dipping a white cotton stick into a clear yellow cobalt test solution containing nitroso R salt, followed by rubbing of the cotton stick for 20–30 seconds against the test item. A colour change from yellow to red–orange indicates a positive test reaction. The spot test detects approximately 8 ppm cobalt in...
The Report on Carcinogens includes two separate listings (i.e., profiles) for cobalt-related exposures: Cobalt and Cobalt Compounds That Release Cobalt Ions In Vivo and Cobalt-Tungsten Carbide: Powders and Hard Metals. Cobalt and cobalt compounds as a class are listed for the first time in the Fourteenth Report on Carcinogens, and this listing includes and supersedes the listing for cobalt sulf...
The effects of methylcobalamin (vitamin B12) injection (75mg kg ) on cobalt levels in autism spectrum disorders (ASDs) and potential toxic effects of cobalt on human neurons were evaluated. A cohort of ASDs (n1⁄4 72) presenting to the Genetic Centers of America were evaluated for the frequency of methylcobalamin injections and cobalt levels using Laboratory Corporation of America (LabCorp) test...
silica ferric hydrogensulfate is an efficient heterogeneous catalyst for the cyclization of 2- aminochalcones to the corresponding 2,3-dihydroquinolin- 4(1h)-ones. this intramolecular aza michael reaction was carried out in high yields using chalcones bearing of electron donating and electron withdrawing groups. the catalyst is reusable without significant decreases in its activity after four t...
Cobalt is a nutrient to phytoplankton, but knowledge about its biogeochemical cycling is limited, especially in the Pacific Ocean. Here, we report sections of dissolved cobalt and labile dissolved cobalt from the US GEOTRACES GP16 transect in the South Pacific. The cobalt distribution is closely tied to the extent and intensity of the oxygen minimum zone in the eastern South Pacific with highes...
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