The morphology of titanium dioxide and titanium dioxide-tungsten trioxide nanocomposite films fabricated by anodizing in a glycerol solution containing 0.13 M NH4F and different quantity of Na2WO4 was investigated as a function of sodium tungstate concentrations. The effects of sodium tungstate concentration on the surface morphology were observed by scanning electron microscopy (SEM). It was c...

Tungsten trioxide (WO3) nanostructures were synthesized by hydrothermal method using sodium tungstate (Na2WO4 2H2O) alone as starting material, and sodium tungstate in presence of ferrous ammonium sulfate [(NH4)2 Fe(SO4)2 6H2O] or cobalt chloride (CoCl2 6H2O) as structure-directing agents. Orthorhombic WO3 having a rectangular slab-like morphology was obtained when Na2WO4 2H2O was used alone. W...

The hyperthermophilic archaeon Pyrococcus furiosus expresses five aldehyde oxidoreductase (AOR) enzymes, all containing a tungsto-bispterin cofactor. The growth of this organism is fully dependent on the presence of tungsten in the growth medium. Previous studies have suggested that molybdenum is not incorporated in the active site of these enzymes. Application of the radioisotope (99)Mo in met...

Lead tungstate (PbWO4) and cadmium tungstate (CdWO4) are dense, fast scintillator crystals which have achieved technological importance for high energy radiation detectors and medical imaging, respectively. Calcium tungstate (CaWO4, the mineral scheelite) is an important phosphor for lighting and displays. We recently compared the electronic structures of the four scheelite-structure materials ...

molA (HI1472) from H. influenzae encodes a periplasmic binding protein (PBP) that delivers substrate to the ABC transporter MolB(2)C(2) (formerly HI1470/71). The structures of MolA with molybdate and tungstate in the binding pocket were solved to 1.6 and 1.7 Å resolution, respectively. The MolA-binding protein binds molybdate and tungstate, but not other oxyanions such as sulfate and phosphate,...

The effect of NO23 uptake on cellular pH was studied in maize roots by an in vivo P-NMR technique. In order to separate the effects on cytoplasmic pH due to NO23 uptake from those due to NO23 reduction, tungstate was used to inhibit nitrate reductase (NR). The results confirm that in maize roots tungstate inhibited NR activity. N-NMR in vivo experiments demonstrated the cessation of nitrogen fl...

The effect of NO3- uptake on cellular pH was studied in maize roots by an in vivo 31P-NMR technique. In order to separate the effects on cytoplasmic pH due to NO3- uptake from those due to NO3- reduction, tungstate was used to inhibit nitrate reductase (NR). The results confirm that in maize roots tungstate inhibited NR activity. 15N-NMR in vivo experiments demonstrated the cessation of nitroge...

In order to limit the dispersive use of lead on small arms firing ranges, 5.56-mm bullets with tungsten-nylon composite material cores have been fired at a number of Army training ranges. Tungsten in bullet residues oxidizes when exposed to the atmosphere, yielding an amorphous tungsten oxide (WO3) coating. This coating rapidly dissolves to yield the tungstate anion (WO4), which can migrate in ...