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Showing papers on "Vanadate published in 1975"


Journal ArticleDOI
TL;DR: In this paper, a model is proposed to explain the luminescence properties of YVO4 crystals based on transitions within the VO3-4 ion, which predicts the observed temperature and concentration dependences for the fluorescence intensities and lifetimes.

227 citations


Journal ArticleDOI
TL;DR: Using scanning electron microscopy it was possible to correlate surface alterations with exposure concentrations and cell viabilities so as to suggest a mode and sequence of cell injury which may ultimately lead to cell death.

182 citations


Journal ArticleDOI
TL;DR: Vanadate formation during reactions of V2O5 with CoO, NiO, ZnO, MgO, and MnO has been studied in this paper, where the initial products of solid-solid reaction with Zn2V2O7, mg3V4O13 and MnV2E6 respectively.
Abstract: Vanadate formation during reactions of V2O5 with CoO, NiO, ZnO, MgO and MnO has been studied. The initial products of solid-solid reaction with ZnO, MgO and MnO are Zn2V2O7, Mg3V4O13 and MnV2O6 respectively. CoO and NiO predominantly form the vanadate which corresponds to the stoichiometry of the initial oxide mixture. Subsequent formation of ortho-, pyro- and metavanadates as intermediates indicate that the principal mechanistic process is the transport of V2O5 to the reaction interface.

38 citations



Journal ArticleDOI
TL;DR: In this paper, the crystal structure of NaVO3 was solved using three dimensional X-ray data and refined to an R-value of 0.077 for 375 observed reflections.
Abstract: The crystal structure of ferroelectric sodium meta vanadate, NaVO3 has been solved using three dimensional X-ray data and refined to an R-value of 0.077 for 375 observed reflections. The crystal belongs to the monoclinic system with space group Cc and with unit cell dimensions a = 10.494 (9) A, b = 9.434 (7) A, c = 5.863 (6) A and β = 108° 48' in the room temperature ferroelectric phase. The unit cell dimensions in the high temperature paraelectric phase (above 380°C) are a = 10.595 (15) A, b = 9.671 (10) A, c = 5.926 (8) A and β = 108° 45' with space group C2/c. The crystal structure may be viewed as consisting of alternate channels of sodium polyhedra and VO4 tetrahedra.

24 citations


Journal ArticleDOI
TL;DR: In this article, it is shown that lead sulphate, PbSO4, shows Pb2+ emission with a large Stokes shift, and energy transfer has been observed from the Pb 2+ ions to several luminescent centres, viz., tungstate, molybdate, vanadate and rare earths.

16 citations


Journal ArticleDOI
TL;DR: In this article, a number of variations of Durif's NaCa2Cu2V3O12 and its variants were synthesized as phase-pure garnets, and the general formulae of the garnets attempted were [A2++B+] M2++V3 O12 (Type I) and A3+ [B+M++] V3O 12 (Type II), where A++ = Mg, Sr, Pb, Cd or Ba, M++ = Co, Ni, Cu or Zn and B+ = Li

16 citations




Journal ArticleDOI
TL;DR: In this article, it was shown that the energy transfer from vanadate group to trivalent rare earth ions is temperature independent, but depends strongly on the choice of the host.

4 citations



Journal ArticleDOI
TL;DR: In this article, a new procedure for simultaneous preconcentration, separation, and determination of permanganate, chromate and vanadate was developed for aqueous solutions containing p.p.b. levels of these anions.

Patent
23 Apr 1975
TL;DR: A method of providing an object of silicon steel with a heat resistant, electrically insulating coating comprises applying a vanadium compound (other than an alkali metal vanadate) and particles of at least one compound selected from an oxide, hydroxide or a carbonate of an alkaline earth metal, or an oxide or a hydroxides of aluminium and thereafter subjecting the coated article to heating at a temperature of at at least 850‹ C The heating may be performed in a nitrogen or hydrogen atmosphere.
Abstract: 1391827 Enamelling silicon steel ALLMANNA SVENSKA ELEKTRISKA AB 13 June 1972 [14 June 1971 5 May 1972] 27543/72 Heading C1M [Also in Divisions B2 and C7] A method of providing an object of silicon steel with a heat-resistant, electrically insulating coating comprises applying a vanadium compound (other than an alkali metal vanadate) and particles of at least one compound selected from an oxide, hydroxide or a carbonate of an alkaline earth metal, or an oxide or a hydroxide of aluminium and thereafter subjecting the coated article to heating at a temperature of at least 850‹ C The heating may be performed in a nitrogen or hydrogen atmosphere The alkaline earth metal is preferably magnesium The vanadium compound may be vanadium (V) oxide, an alkaline earth metal vanadate, an aluminium or titanium vanadate, ammonium vanadate or a vanadium acid Vanadium (V) carbide may also be used A quantity of vanadium compound which stoichiometrically corresponds to a quantity of vanadium (V) oxide of 0A001-10 gm/m 2 of the surface of the object is sufficient The total quantity of alkaline earth metal compound or aluminium compound together with the vanadium compound, calculated as vanadium (V) oxide is 3-30 gm/m 2 of the surface of the object The vanadium compound and the other component may be applied in the form of an aqueous suspension or as a dry powder The slurry may also be applied by means of spraying When used in sufficient amounts the vanadium compound oxidises silicon in the silicon steel with grain orientation so that it reacts with the alkaline earth metal or aluminium compound to form glass The silicon content of silicon steel with grain orientation is about 3% by weight The thickness of the glass film formed is usually 0A1-10 microns The particle size of the alkaline earth metal compound or aluminium compound is desirably less than 250 microns, whilst the vanadium compound, if in granular form, preferably has a grain size of 1-25 microns Examples refer to the treatment of silicon with mixtures of either magnesium oxide, magnesium carbonate or magnesium hydroxide (eg 98-99 parts) with vanadium oxide (eg 1-2 parts) or a mixture of magnesium oxide (98 parts) and magnesium vanadate (2 parts) In an appartus for use in applying the protective layer a strip of silicon steel 1 passes under a roller 3 which rotates in a pan 4 containing the slurry 5 of the particulate meterial The coated strip passes between wiping rollers 6 and 7 and then into a furnace 8 where it is dried at about 100‹ C The coil is wound on to a reel 11 before heating in a batch annealing furnace

Patent
18 Sep 1975
TL;DR: In this article, a mixture of sodium vanadate and sulphate with ammonium sulphate at pH 7.5 to 9 and at 25-35 degrees C, pref. with vigorous stirring is prepd. by precipitating solns.
Abstract: of low alkali content is prepd. by precipitating solns. of sodium vanadate and sulphate with ammonium sulphate at pH 7.5 to 9 and at 25-35 degrees C, pref. with vigorous stirring. Higher purity of prod. reduces losses in aluminothermic redn. of V2O5 to vanadium, caused by Na2O, which consumes more Al and is reduced to sodium, which causes the dust produced in the process to contain appreciable amts. of vanadium. Yield in the pptn. is raised from 83% to 97%.