نتایج جستجو برای: vanadium
تعداد نتایج: 7597 فیلتر نتایج به سال:
The biological image of the transition element vanadium ferments a great deal of contradiction-from toxicity to essentiality. Importance of this element as micro-nutrient is yet to be unequivocally accepted by biologists and biomedical scientists. In spite of toxicity, it seems interesting to analyze the different biological roles of the element. Vanadium compounds have been proven to be associ...
A new solvo-hydrothermal method has been developed for the synthesis of uniform vanadium oxide nanocrystals (NCs) with various sizes and shapes in aliphatic amine/toluene/water using V(V) diperoxo alkylammonium complexes. The vanadium complex precursors were prepared from an ion exchange reaction of V(V) diperoxo gels and tetraalkylammonium bromide in the water-toluene mixture using H(2)O(2) so...
This study describes a new simple, sensitive and selective catalytic kinetic spectrophotometricmethod for the determination of vanadium (V). The method is based upon the catalytic effect ofvanadium (V) on the oxidation of Carminic acid by bromate in sulfuric acid media. The reaction wasfollowed spectrophotometrically by measuring the decrease in absorbance at 490 nm and thedependence of sensiti...
Fuel oil used in power plants contain metal impurities like Vanadium. After combustion, this metal remains in boiler fuel ash in the form of oxide. In this research, extraction of Vanadium oxide from fuel ash has been investigated. Two processes were used for this purpose. A pyro- hydrometallurgy and a hydrometallurgy process. In the pyro-hydrometallurgy process, using sodium carbonate, salt ro...
The nomenclature of selected vanadium compounds is given in Table 1. Chem. Abstr. Serv. Reg. No.: 1314-62-1 Deleted CAS Reg. No.: 12503-98-9; 56870-07-6; 87854-55-5; 87854-56-6; 16616537-3; 172928-47-1; 184892-22-6; 200577-85-1; 203812-34-4; 251927-12-5; 41054690-6 Chem. Abstr. Serv. Name: Vanadium oxide (V2O5) IUPAC Systematic Name: Vanadium oxide Synonyms: CI 77938; divanadium pentaoxide; pen...
Recent studies of supported vanadium oxide catalysts have revealed that the vanadium oxide component is present as a twodimensional metal oxide overlayer on oxide supports (i.e., A1203, TiO2) (1-9). These surface vanadium oxide species are generally more selective and active than bulk, crystalline V205 for the partial oxidation of hydrocarbons (3, 5, 10, 11). The molecular structures of these s...
Introduction: Gastric cancer is the fourth most common cancer worldwide and the second leading cause of death from cancer. In recent years, advances in cancer therapy have raised the specter of developing effective agents of high-impact diseases, like gastric cancer, which remains one of the major causes of cancer deaths in the world. Recently it has been demonstrated that vanadium compounds ex...
The effect of vanadium oxide as support and promoter on supported rhodium catalysts on the CO hydrogenation has been investigated at 0.15 and 4.0 MPa. Rh/V,O, reduced at 723 K has a good selectivity toward oxygenated products, especially C,-oxygenates, but has a low activity added as a promoter to catalysts consisting and stability. Vanadium oxide of rhodium supported on silica and alumina show...
Vanadium recovery of Thermal Power Plant Ash (TPPA) is an attractive process which simultaneously satisfies the pollution control standards regarding TPPA disposal and provides a valuable source of vanadium for industrial demands. In the present research work, sulfuric acid leaching route has been employed for vanadium recovery from an Iranian TPPA. Effects of acid concentration, temperature, a...
background: oral vanadyl sulfate (vanadium) induces normoglycemia, proliferates beta cells and prevents pancreatic islet atrophy in streptozotocin-induced diabetic rats. soteriological method is used to quantitate the proliferative effects of vanadium on beta-cell numbers and islet volumes of normal and diabetic rats. methods: adult male sprague-dawley rats were made diabetic with intravenous s...
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