3,694 research outputs found

    Innovative techniques for the production of energetic radicals for lunar processing including cold plasma processing of local planetary ores

    Get PDF
    Hydrogen reduction of ilmenite has been studied by a number of investigators as a potential means for recovery of oxygen from lunar soil. Interest in this process has always rested with the simplicity of the flow diagram and the utilization of established technology. Effective utilization of hydrogen in the reduction process at temperatures of 1200 C and below has always been disappointing and, as such, has led other investigators to focus attention on other systems. Effective utilization of hydrogen in the reduction of ilmenite can be significantly enhanced in the presence of a non-equilibrium hydrogen plasma. Ilmenite at solid specimen temperatures of 600 C to 970 C were reacted in a hydrogen plasma. Those experiments revealed that hydrogen utilization can be significantly enhanced. At a specimen temperature of 850 C the fraction of H2 reacted was 24 percent compared to the 7 percent theoretical limit calculated with thermodynamic theory for the same temperature. An added advantage for a hydrogen plasma involves further reduction of TiO2. Reduction of the iron oxide in ilmenite yields TiO2 and metallic iron as by products. Titanium forms a number of oxides including TiO, Ti2O3, Ti3O5 and the Magneli oxides (Ti4O7 to Ti50O99). In conventional processing of ilmenite with hydrogen it is possible to reduce TiO2 to Ti7O13 within approximately an hour, but with poor utilization of hydrogen on the order of one mole of H2 per thousand. In the cold or non-equilibrium plasma TiO2 can be rapidly reduced to Ti2O3 with hydrogen utilization exceeding 10 percent. Based on design considerations of the plasma reactor greater utilization of the hydrogen in the reduction of TiO2 is possible

    Intermediaries and payments instruments

    Get PDF
    We study an economy in which intermediaries have incentives to issue circulating liabilities as part of an equilibrium. We show that, with arbitrarily small transactions costs, only the liabilities of intermediaries will circulate, and not those of other private sector agents. Therefore, our model connects intermediation activity with the issuance of payments media, a connection that has not been made in earlier literature. We also describe conditions under which equilibrium outcomes may be volatile when private liabilities circulate. Finally, we use our model to suggest a resolution of the "banknote underissue puzzle" of Cagan (1993).Monetary policy ; Bank notes ; Payment systems

    The value of inside and outside money: expanded version

    Get PDF
    We study dynamic economies in which agents may have incentives to hold both privately-issued (a.k.a. inside) and publicly-issued (a.k.a. outside) circulating liabilities as part of an equilibrium. Our analysis emphasizes spatial separation and limited communication as frictions that motivate monetary exchange. We isolate conditions under which a combination of inside and outside money does and does not allow the economy to achieve a first-best allocation of resources. We also study the extent to which the use of private circulating liabilities alone, or the use of public circulating liabilities alone, can address the frictions that lead to monetary exchange. We identify conditions under which both types of liabilities are essential to efficiency. However, even when these conditions are satisfied, we show that political economy considerations may lead to a prohibition against private circulating liabilities. Finally, we analyze the consequences of such a prohibition for the determinacy of equilibrium, and for endogenously arising volatility.Money ; Money theory

    The value of inside and outside money

    Get PDF
    We study dynamic economies in which agents may have incentives to hold both privately-issued (a.k.a. inside) and publicly-issued (a.k.a. outside) circulating liabilities as part of an equilibrium. Our analysis emphasizes spatial separation and limited communication as frictions that motivate monetary exchange. We isolate conditions under which a combination of inside and outside money does and does not allow the economy to achieve a first-best allocation of resources. We also study the extent to which the use of private circulating liabilities alone, or the use of public circulating liabilities alone, can address the frictions that lead to monetary exchange. We identify conditions under which both types of liabilities are essential to efficiency. However, even when these conditions are satisfied, we show that political economy considerations may lead to a prohibition against private circulating liabilities. Finally, we analyze the consequences of such a prohibition for the determinacy of equilibrium, and for endogenously arising volatility.Money ; Money theory

    Cold plasma processing of local planetary ores for oxygen and metallurgically important metals

    Get PDF
    The utilization of a cold plasma in chlorination processing is described. Essential equipment and instruments were received, the experimental apparatus assembled and tested, and preliminary experiments conducted. The results of the latter lend support to the original hypothesis: a cold plasma can both significantly enhance and bias chemical reactions. In two separate experiments, a cold plasma was used to reduce TiCl4 vapor and chlorinate ilmenite. The latter, reacted in an argon-chlorine plasma, yielded oxygen. The former experiment reveals that chlorine can be recovered as HCl vapor from metal chlorides in a hydrogen plasma. Furthermore, the success of the hydrogen experiments has lead to an analysis of the feasibility of direct hydrogen reduction of metal oxides in a cold plasma. That process would produce water vapor and numerous metal by-products

    Cold plasma processing of local planetary ores for oxygen and metallurgically important metals

    Get PDF
    The utilization of a cold or nonequilibrium plasma in chlorination processing is discussed. Titanium dioxide (TiO2) was successfully chlorinated at temperatures between 700 and 900 C without the aid of carbon. In addition to these initial experiments, a technique was developed for determining the temperature of a specimen in a plasma. Development of that technique has required evaluating the emissivity of TiO2, ZrO2, and FeOTiO2 and analyzing the specimen temperature in a plasma as a function of both power absorbed by the plasma and the pressure of the plasma. The mass spectrometer was also calibrated with TiCl4 and CCl4 vapor

    Environmental Racism and Invisible Communities

    Get PDF

    The Legacy of American Apartheid and Environmental Racism

    Get PDF

    Deadly Waiting Game: An Environmental Justice Framework for Examining Natural and Man-Made Disasters Beyond Hurricane Katrina [abstract]

    Get PDF
    Presenter: Robert D. Bullard, Ph.D., Professor of Sociology, Clark Atlanta University 1 page

    Deadly Waiting Game: An Environmental Justice Framework for Examining Natural and Man-Made Disasters Beyond Hurricane Katrina [abstract]

    Get PDF
    Presenter: Robert D. Bullard, Ph.D., Professor of Sociology, Clark Atlanta University 1 page
    corecore