We compare aspects of biological X-ray absorption spectroscopy (XAS) studies of cations and anions, and report on some examples of anion binding in biological systems. Brown algae such as Laminaria digitata (oarweed) are effective accumulators of I from seawater, with tissue concentrations exceeding 50 mM, and the vanadate-containing enzyme haloperoxidase is implicated in halide accumulation. W...

An experiment to search for double beta processes in Cd by using cadmium tungstate crystal scintillator enriched in Cd (106CdWO4) in coincidence with the four crystals HPGe detector GeMulti is in progress at the STELLA facility of the Gran Sasso underground laboratory of INFN (Italy). The 106CdWO4 scintillator is viewed by a low-background photomultiplier tube through a lead tungstate crystal l...

The luminescence of complex ions like vanadate, niobate and tungstate is well known and has been studied intensively [1]. We have shown that edgeor face-sharing octahedra of this type are luminescent species with high quenching temperatures [2,3]. Examples are Mg4Nb20g and BasSrNb209 with Nb20g8_ anions and Ba3W20g with W2O96anions. These anions consist of face-sharing niobate and tungstate oct...

We report our recent work on obtaining on-chip lasers in crystalline double tungstate waveguides using focused-ion-beam (FIB) nanostructuring. Photonic cavity structures were defined by forming deeply etched Bragg gratings in KGdxLu1-x(WO4)2:Yb 3+ using FIB milling. The FIB milling procedure was optimized and gratings more than 4 μm in depth with an improved total sidewall angle of about 5 wer...

An organism identified as Pseudomonas putida was isolated from an enrichment culture with 2-furoic acid as its sole source of carbon and energy. The organism contained a 2-furoyl-coenzyme A (CoA) synthetase to form 2-furoyl-CoA and a 2-furoyl-CoA dehydrogenase to form 5-hydroxy-2-furoyl-CoA as the first two enzymes involved in the degradation. Tungstate, the specific antagonist of molybdate, de...

Tungsten (VI) speciation in hydrothermal solutions is investigated through in-situ Raman spectroscopy coupled with the fused silica glass capillary technique at temperatures up to 400 °C. The effect of temperature, pH, chlorinity and carbonate are evaluated systems highly soluble salts Na2WO4 Na6W12O39. At all temperatures, tungstate ion WO42? (927 cm?1) only W species solution pH > 10. a given...

Tungsten is one of the strategic metals produced from tungsten ores through sodium tungstate. The hydrometallurgical process a common technology for extracting tungstate high-grade concentrates. grade ore decreasing, and mineral processing to produce concentrate suitable becoming more difficult. It desirable develop new effectively recover complex low-grade ores. A fundamental study on pyrometa...