Nanosized Co-Cr-V alloy powders were synthesized via coprecipitation method. Effects of precipitants ((NH₄)₂C₂O₄·H₂O and Na₂CO₃) and pH were investigated by X-ray diffraction (XRD), Zeta potential analyzer, thermogravimetry-differential scanning calorimetry (TG-DSC), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and scanning electron microscopy (SEM). Co-Cr-V alloy powders w...

An optical absorption spectrum, structural and chemical data of green Vand Cr-bearing tourmaline from the graphite deposit at Weinberg Mountain, west of the village of Amstall, Lower Austria, were obtained. To address the role of V and Cr in the spectrum of tourmaline, examination of additional samples of Vand Cr-containing tourmalines was conducted. This study confi rmed that V and Cr produce ...

Titanium(ii) solutions, prepared by dissolving titanium metal in triflic acid and HF, react readily with derivatives of Cr(vi), Cr(v) and Cr(iv). Reductions of Cr(vi) and Cr(iv), carried out with [Co(NH(3))(5)Br](2+) as a scavenger for Cr(ii), yield no detectable Co(2+), indicating that 2e(-) steps, bypassing Cr(v) and Cr(iii), are not operative. Catalysis by Ti(iv) is observed only for reducti...

bimetallic pt-v supported by gamma-alumina is used to observe the changes of nheptanewhen passed over this catalyst. the pt concentration was kept constant at0.1wt% while the concentration of the vanadium was 0.5wt%. the activity andselectivity of catalyst have been determined under conditions at 450-500 degreescentigrade and 15-30 attn. the experimental results show that the addition of second...

The chromium(I) dinitrogen complex [(i-Pr2Ph)2nacnacCr]2(μ-η(2):η(2)-N2) catalyzes the selective trimerization of ethylene to 1-hexene at ambient pressure and temperature, and in the absence of any cocatalyst. After the conversion of the substrate, the catalyst cleanly converts to another chromium(I) species, namely [(i-Pr2Ph)2nacnacCr]2(μ-η(2):η(2)-C2H4), which is not catalytically active. Bin...

In this study, some metals (aluminium, chromium, copper, iron, manganese, lead, zinc and vanadium) and metalloid (silicon) were determined in water, sediment and some tissues of fish Cyprinus carpio from Mogan Lake. Fish samples were caught in March 2007. As a result of the examination of metals in the water aluminium has the lowest and silicon has the highest concentration. In sediment samples...