Ultrafine magnesium

Two methods of producing nanostructured MgH were already briefly mentioned in Sect. 2.1.3.3 and 2.1.5. Shao et al. [44] used the hydrogen plasma-metal reaction to obtain ultrafine magnesium with an average size of about 300 nm. The activation of... 

Examination of 95 workers exposed to an unspecified concentration of magnesium oxide dust revealed slight irritation of the eyes and nose the magnesium level in the serum of 60% of those examined was above the normal upper limit of 3.5mg/dl. No evidence of any pulmonary inflammatory response was found in six volunteers after short-term (36min) exposure to high concentrations (137.0mg/m ) of fine and ultrafine magnesium oxide particles. ... 

Kuschner WG, Wong H, D Alessandro A et al Human pulmonary responses to experimental inhalation of high concentration fine and ultrafine magnesium oxide particles. Environ Health Perspect 105(11) 1234—1237, 1997... 

H. Shao, Y. Wang, H. Xu, X. Li, Hydrogen storage properties of magnesium ultrafine particles prepared by hydrogen plasma-metal reaction, Mater Sci. Eng. B 110 (2004) 221-226. 

Goap" is the name given to the crude intermediate product obtd in the manuf of magnesium at the Henry Kaiser plant. It consists of a mixt of ultrafine particles of Mg, Mg carbide, magnesia, carbon, naphtha asphalt, all in the form of thick paste. The material proved to be a suitable source of Mg in prepn of incendiary compns for bombs. The most successful of such mixtures was known during WWlI asPyrogel or PT-1... 

Sometimes nanosized powders are also referred as ultrafine (UF) powders with an equivalent size of 10 to a few hundred nanometers. The commonly employed fuels for explosives, propellants and pyrotechnics are aluminum (Al), magnesium (Mg) and boron (B). However, the share in terms of quantity consumed is maximum for aluminum. 

The ultrafine singlecrystal magnesium oxide was kindly provided by Ube Industries... 

The chapters in Characterization and Catalyst Development An Interactive Approach, assembled from both academic and industrial contributors, give a unique perspective on catalyst development Some chapters thoroughly characterize the catalyst prior to plant evaluation, whereas others utilize characterization to explain performance variances. Some new types of catalysts incorporated into this volume include the preparation of novel catalyst supports based on alumina and hydrous titanates. Attrition-resistant catalysts and ultrafine ceramics were prepared by modified spray-drying methods. New catalyst compositions based on vanadium-containing anionic clays were proposed for oxidation. A recently commercialized catalyst based on magnesium spinel was proposed for use in the abatement of sulfur oxide pollutants in fluid... 

Hydrous magnesium silicate, is an industrial talc. It is available in four grades, two fine talcs and two ultrafine air milled grades with excellent white color. 

K Matsuura, Y Hashimoto, O Takayasu, K Nitta, and Y Yoshida, Heat-stable ultrafine single crystal magnesium oxide and its character as a support matenal for high-temperature combustion catalysts, Appl Catal 74 273 (1991)... 

Stark JV, Park DG, Lagadic I, Klabunde KJ (1996) Nanoscale metal oxide particles/clusters as chenucal reagents-tJnique surface chemistry on magnesium oxide as shown by enhanced adsorption of acid gases (sulfur dioxide and carbon dioxide) and pressure dependence. Chem Mater 8 1904-1912 Stolzenburg MR, McMurry PH (1991) An ultrafine aerosol condensation nucleus counter. Aerosol Sci Tech 14 48-65... 

C.R. Bickmore, K. Waldner, D.R. Treadwell and R.M. Laine, Ultrafine Spinel Powders by Flame Spray Pyrolysis of a Magnesium Aluminum Double Alkoxide, J. Am. Ceram. Soc., 79, 1419-1423 (1996). 

Exposure to air polluted with particles less than 2.5 pm (2500 nm) in size was associated with epidemiologically adverse cardiopulmonary health consequences in humans. In this study, six healthy volunteers were exposed to fine and ultrafine but nontoxic magnesium oxide (MgO) particles (70a). Exposiue levels were mean + standard deviation for exposure was 4,138 + 2163 minutes x mg/m. Ninety-eight percent of the particles were fine (<2.5 pm 2500 nm) and 28% were ultrafine (< 100 nm). No differences were noted from controls, as indicated by bronchoalveolar lavage (BAL) inflammatory cell concentrations, interleukin concentrations (ILl, IL6, IL8), tumor necrosis factor, pulmonary function, or peripheral blood neutrophil concentrations (70a). Thus, volunteers who inhaled nontoxic MgO at high levels over considerable time periods showed no indications of inflammation in the lung as indicated by BAL washings. 

So-called ultrafine metal powders below 1 i in diameter can be made by pyrogenic dissociation of the vapors of the carbonyls of iron, nickel, and cobalt. Aluminum of a particle size below the resolving power of the electron microscope has been formed by evaporation and condensation under vacuum in an inert atmosph e. Similarly, evaporated magnesium has been quenched by JP-4 fuel for directly making a slurry fuel. Also, long ball-milling fine magnesium powder in the presence of a surfactant can lead to particles below I n. Iron or nickel electrolytically deposited on a mercury cathode form very active, often pyrophoric, fine powdm that, however, can be stabilized in order to be handled in air. 

Keywords tin, tin oxide, zinc hydroxystannate, zinc stannate, organotin compounds, antimony trioxide, alumina trihydrate, magnesium hydroxide, titanium dioxide, molybdenum trioxide, iron oxide, zinc borate, alumina, halogenated flame retardants, metal halides, thermal analysis, Mossbauer spectroscopy, fire-retardant mechanism, ultrafine powders, coated fillers. 

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