46 research outputs found

    Anodic dissolution of metals in oxide-free cryolite melts

    Get PDF
    The anodic behavior of metals in molten cryolite-alumina melts has been investigated mostly for use as inert anodes for the Hall-Héroult process. In the present work, gold, platinum, palladium, copper, tungsten, nickel, cobalt and iron metal electrodes were anodically polarized in an oxide-free cryolite melt (11%wt. excess AlF3 ; 5%wt. CaF2) at 1273 K. The aim of the experiments was to characterize the oxidation reactions of the metals occurring without the effect of oxygen-containing dissolved species. The anodic dissolution of each metal was demonstrated, and electrochemical reactions were assigned using reversible potential calculation. The relative stability of metals as well as the possibility of generating pure fluorine is discussed

    Higher whole-blood selenium is associated with improved immune responses in footrot-affected sheep

    Get PDF
    We reported previously that sheep affected with footrot (FR) have lower whole-blood selenium (WB-Se) concentrations and that parenteral Se-supplementation in conjunction with routine control practices accelerates recovery from FR. The purpose of this follow-up study was to investigate the mechanisms by which Se facilitates recovery from FR. Sheep affected with FR (n = 38) were injected monthly for 15 months with either 5 mg Se (FR-Se) or saline (FR-Sal), whereas 19 healthy sheep received no treatment. Adaptive immune function was evaluated after 3 months of Se supplementation by immunizing all sheep with a novel protein, keyhole limpet hemocyanin (KLH). The antibody titer and delayed-type hypersensitivity (DTH) skin test to KLH were used to assess humoral immunity and cell-mediated immunity, respectively. Innate immunity was evaluated after 3 months of Se supplementation by measuring intradermal responses to histamine 30 min after injection compared to KLH and saline, and after 15 months of Se supplementation by isolating neutrophils and measuring their bacterial killing ability and relative abundance of mRNA for genes associated with neutrophil migration. Compared to healthy sheep, immune responses to a novel protein were suppressed in FR-affected sheep with smaller decreases in FR-affected sheep that received Se or had WB-Se concentrations above 250 ng/mL at the time of the immune assays. Neutrophil function was suppressed in FR-affected sheep, but was not changed by Se supplementation or WB-Se status. Sheep FR is associated with depressed immune responses to a novel protein, which may be partly restored by improving WB-Se status (> 250 ng/mL)

    Multinationals, host countries and subsidiary development: Falconbridge Nikkelverk in Norway, 1929-39

    No full text
    Multinational companies and their subsidiaries have been important actors in the world economy. However, we know relatively little about the evolution of subsidiaries and their adaption to host country conditions. This article is a case study of a Norwegian subsidiary of the Canadian mining multinational Falconbridge Nickel Mines Ltd. It examines what autonomy the subsidiary had, how the autonomy was used, its development of knowledge and how it adapted to Norwegian ways of doing business. The article shows that subsidiaries may contribute significantly to the development of their mother companies. It highlights four factors that influenced the degree of autonomy and the evolution of subsidiaries in the inter-war era; namely host country politics, the line of business, the configuration of knowledge within the given multinational company and in case of acquisitions; the prehistory of the subsidiary.subsidiaries, subsidiary autonomy, multinational companies, host countries, nickel industry, Falconbridge,

    The crusting behavior of smelter aluminas

    No full text
    corecore