Vanadium K-edge X-ray-absorption spectra were collected for samples of thionine-oxidized, super-reduced (during enzyme turnover) and dithionite-reduced VFe-protein of the vanadium nitrogenase of Azotobacter chroococcum (Acl*). Both the e.x.a.f.s and the x.a.n.e.s. (X-ray-absorption near-edge structure) are consistent with the vanadium being present as part of a VFeS cluster; the environment of ...

Ž . The environmental impact of both the vanadium redox battery vanadium battery and the lead-acid battery for use in stationary applications has been evaluated using a life cycle assessment approach. In this study, the calculated environmental impact was lower for the vanadium battery than for the lead-acid one. The net energy storage efficiency of the vanadium battery was greater due to lower...

Solid-phase spectrophotometry has been applied to analysis for trace amounts of vanadium. Vanadium was sorbed in a styrene-divinylbenzene-type anion-exchanger Dowex 1-X8 as a vanadium-4-(2-pyridylazo)resorcinol complex. Resin phase absorbances at 562 and 800 nm were measured directly which allowed the determination of vanadium in the range of 0.1-2.4 ng/ml with a RSD of 1.5%. The method has bee...

Biochemical and haematological profiles of workers exposed to vanadium were compared with those of non-exposed age matched subjects. A significantly positive and dose related correlation between serum vanadium and zinc protoporphyrin (ZPP) was observed. Normal lead concentrations excluded this heavy metal as a possible cause. Inhibition of the reduction of Fe to Fe++ by vanadium is discussed as...

Lithium-based conducting glasses are promising candidates for electrolyte materials of thin-film batteries because they exhibit isotropic ionic conductivity. However, at room temperature most of such conducting glasses exhibit relatively low ionic conductivity values, in the range 10 to 10 S/m. In order to increase the conductivity, some specific additives have been used, one of them being vana...