Neutral vanadium, niobium, and tantalum oxide clusters are studied by single photon ionization employing a 26.5 eV/photon soft x-ray laser. During the ionization process the metal oxide clusters are almost free of fragmentation. The most stable neutral clusters of vanadium, niobium, and tantalum oxides are of the general form (MO2)0,1(M2O5)y. M2O5 is identified as a basic building unit for thes...

V2O5 based materials are attractive cathode alternatives due to the many oxidation state switches of vanadium bringing about a high theoretical specific capacity. However, significant capacity losses are eminent for crystalline V2O5 phases related to the irreversible phase transformations and/or vanadium dissolution starting from the first discharge cycle. These problems can be circumvented if ...

in this research, nano materials with tubular structures are added to sae 20w50 engine oil to study the rate of their effects on the properties of engine oil. multi-walled carbon nanotubes (mwcnts) and vanadium oxide nanotubes (vonts) has been used as two different additive materials, one of them is carbonic and the other is metallic oxides and their effect on  different parameters containing v...

Thermodynamics of reactions of vanadium oxide clusters with SO2 are studied at the BPW91/LANL2DZ level of theory. BPW91/LANL2DZ is insufficient to properly describe relative V-O and S-O bond strengths of vanadium and sulfur oxides. Calibration of theoretical results with experimental data is necessary to compute reliable enthalpy changes for reactions between VxOy and SO2. Theoretical results i...

Boosted by the rapid advances of science and technology in the field of energy materials, Li-ion batteries have achieved significant progress in energy storage performance since their commercial debut in 1991. The development of nanostructured electrode material is regarded as one of the key potentials for the further advancement in Li-ion batteries. This feature article summarizes our recent e...

Copper-manganese oxide catalysts are prepared with an atomic ratio of Cu/Mn=2/1 using a coprecipitation procedure under air atmosphere. The time of aging, i.e., the time that precipitate remains in contact with the precipitating medium, has been varied from 0 (for unaged precursor) to 300 minutes and the effect of precipitate aging time in each atmosphere upon the structure and morphology of di...

In this paper we present the fluorescence decay profiles of vanadium and titanium doped gallium lanthanum sulphide (GLS) glass at various doping concentrations between 0.01 and 1% (molar). We demonstrate that below a critical doping concentration the fluorescence decay profile can be fitted with the stretched exponential function: exp[-(t/τ)], where τ is the fluorescence lifetime and β is the s...

A series of mononuclear V((V)), V((IV)) and V((III)) complexes were investigated by V L-edge near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The spectra show significant sensitivity to the vanadium oxidation state and the coordination environment surrounding the vanadium center. The L-edge spectra are interpreted with the aid of the recently developed Density Functional Theory/...

Kinetic isotopic effects (KIEs) for oxidative dehydrogenation of propane were measured on 10 wt% V2O5/ZrO2. Normal KIEs were obtained using CH3CH2CH3 and CD3CD2CD3 as reactants for primary dehydrogenation (2.8) and combustion (1.9) of propane and for secondary combustion of propene (2.6), suggesting that in all cases C–H bond dissociation is a kinetically relevant step. CH3CH2CH3 and CH3CD2CH3 ...

A solvent-extraction spectrophotometric technique is proposed as a new method for determination of trace quantities of vanadium. Sodium salt of 2-mercapto-pyridine-N-oxide (thione) forms a complex with vanadium instantaneously. The purple 1:2 complex is formed of pH 2.3, easily extracted in chloroform and shows strong absorbance at 500 nm. The extracted complex is found to obey Beer's law i...