Vanadium-niobium oxide catalysts containing variable amounts of vanadium and prepared by coprecipitation were investigated using 51V solid-state NMR. It was found that, in samples containing less than about 8 mol % V2O5, vanadium occurs in three different oxygen environments: in isolated tetrahedra, in comer-sharing tetrahedra (pyrovanadate), and in distorted octahedra. The number of octahedral...

Advanced gas-cooled reactor (AGR) oxide fuels used in the United Kingdom are clad bespoke grade 20%Cr-25%Ni-Nb austenitic stainless steel. Electrochemistry was first applied to correlate breakdown potential with chloride ion concentration, temperature, and pH for this alloy. At near-neutral unsensitized material exhibited a linear Eb = A + B log10[Cl−] relationship, where 0.7 VSCE –0.098 V/deca...

Niobium is recognized as an important alloying element in a number of wrought precipitation-hardened nickel-base alloys. It is the purpose of this paper to examine the role that niobium plays in these alloys and describe the properties that are achieved as a result of its inclusion in wrought superalloys. In addition to the general alloying characteristics of niobium as described in the technic...

Duplex stainless steels are used to replace austenitic in industrial applications, especially the chemical industry where corrosion resistance chloride-containing media is an important requirement. According literature, niobium has a great influence on transformation of phases these (ferrite, austenite and sigma). Given interest evaluating this property terms wear material, aim study was evalua...

Astronomical interest in observing phenomena within the terahertz frequency spectrum has driven demand for extremely sensitive heterodyne receivers. Traditionally, niobium-based SIS tunnel junctions are used by the radio astronomy community in such receivers for observations below 700GHz. Research on novel devices for heterodyne mixing aims to extend experimental capabilities of sensitive recei...