Search results for "vanA"

ChemInform Abstract: New Polymorph of InVO4: A High-Pressure Structure with Six-Coordinated Vanadium.

2014

High-pressure XRD and Raman spectroscopy on orthorhombic InVO4 (space group Cmcm, Z = 4) reveal the existence of a new wolframite-type polymorph of InVO4 near 7 GPa.

The Effect of Vanadium on the Content of Chlorophyll, P-700 and Cytochrome f at Different Light Intensities in Chlorella fusca

1980

Summary Cells of Chlorella fusca, were grown in liquid medium supplemented ,vith O.2% glucose and varied concentrations of vanadium both at 5 different light intensities and in the dark. \Vith increasing concentrations of vanadium the content of chlorophyll, P-700 and cytochrome f increased as well, each, however, in a different way. At the saturating concentration of 20 µg vanadium per litre the pigment content per dry weight was double as high as that of the vanadium-free control; the ratio of chlorophyll a/chlorophyll b increased from 2.1 to 2.9. The content of P-700 at saturating vanadium concentration was four times higher than that of the control when based on dry weight and double as…

Vanadium complexes with multidentate amine bisphenols

2014

The reaction of VO(acac)2 (acac(-) = acetyl acetonate) with tripodal glycine bisphenol H3L(1) under an ambient atmosphere yields a hexacoordinated vanadium(iv) complex [V(acac)(L(1))] (1). The corresponding reactions with tripodal 2-propanolamine bisphenol H3L(2) and potentially pentadentate ethoxyethanolamine bisphenol H3L(3) lead to the oxidation of the metal centre and formation of mononuclear oxovanadium(v) complexes [VO(L(2))] (2) and [VO(L(3))] (3), respectively. Alternatively, these latter two complexes can be prepared using VOSO4·5H2O or VO(OPr)3 as a precursor. The CV of 1 in an ACN solution shows a reversible one-electron process at E1/2 = +1.18 V, whereas 2 and 3 have an irrevers…

Synthesis and catalytic properties for olefin polymerization of new vanadium complexes containing silsesquioxane ligands with different denticity

2017

Development of a new method for the separation of vanadium species and chloride interference removal using modified silica capillaries-DIN-ICP-MS

2004

Abstract A new on-line method for the separation of vanadium (IV) and vanadium (V) as well as for the removal of ClO+ mass spectral interference on vanadium determination by quadrupole-ICP-MS has been developed. The sample introduction system consists of a modified fused silica capillary coupled to a direct injection nebuliser (DIN), between the solvent delivery system and the ICP. Fused silica capillaries were treated with different anion and cation exchanger reagents and were tested for the retention of Cl− and the separation of vanadium ions at μg l−1 levels. A suitable strong anion exchanger functional group (3-aminopropyltrimethoxy silane) was selected. Chlorine anions were retained in…

Development of an isotope dilution laser ablation ICP-MS method for multi-element determination in crude and fuel oil samples

2009

An inductively coupled plasma isotope dilution mass spectrometric (ICP-IDMS) method with direct introduction of the isotope-diluted sample into the plasma by laser ablation was developed for accurate, sensitive, fast, and simultaneous determination of trace metals in different oil samples. Metallo-organic solutions of isotope spikes (50V, 53Cr, 65Cu, 57Fe, 62Ni, 68Zn, 113Cd, 117Sn, and 206Pb) were prepared from corresponding aqueous stock solutions by using liquid–liquid extraction of complexed metal ions in isobutyl methyl ketone. The isotope-diluted sample was absorbed by a cellulose material, which was fixed in a special PTFE holder for ablation, using a laser system with high ablation r…

Effect of particle size distribution in laser-induced breakdown spectroscopy analysis of mesoporous V–SiO2 catalysts

2011

In this paper, the effect of particle size on Laser-Induced Breakdown Spectroscopy (LIBS) analysis of mesoporous V–SiO2 catalyst samples was investigated. The measurements were realized on three LIBS devices with different parameters. Concentrations of V in samples used for LIBS experiments previously determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES) varied from 1.2 to 4.7 w/w%. Granulometry of silica samples was modified by two grinding methods (conventional vibration mill and cryogenic mill) and three sets of samples with different particle size distributions were obtained. Ground samples were then deposited in the form of a thin layer on the adhesive tape a…

Vanadium and molybdenum concentrations in particulate from Palermo (Italy): analytical methods using voltammetry

2014

The main purpose of this work was to develop a reliable method for the determination of vanadium (V) and molybdenum (Mo) in atmosphere particles or aerosols because they can not be readily measured using conventional techniques. For this research, 30 particulate samples were collected from five different stations located at Palermo, Italy. We used the catalytic adsorptive stripping voltammetry and differential pulsed voltammetry to measure Vand Mo in atmospheric particulate, respectively. The represented method includes advantages of high sensitivity, high selectivity, simplicity, reproducibility, speed and low costs. The quantification limits for V and Mo are, respectively, 0.57 and 0.80 n…

Gozos en alabanza de nuestra Señora de Vallivana

1750

El full orlat Grav. xil. enmarcat de la Mare de Déu, flanquejat per gerros amb flors El text del goig a tres col. separades per filets

Linguistica Lettica, Nr. 30

2022

Žurnāla "Linguistica Lettica" 30. numura tēma ir "Valodas bagātība slēpjas tās dažādībā". The theme of the 30th issue of the annual journal "Linguistica Lettica" is "The richness of language lies in its diversity".