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High pressure neodymium

The release of nitrogen from solution in the blood, with formation of small bubbles, is the cause of most of the symptoms and changes found in compressed air illness (caisson disease). It is a narcotic at high concentration and high pressure. Both the narcotic effects and the bends are hazards of compressed air atmospheres such as found in underwater diving. Nonflammable gas. Can react violently with lithium, neodymium, titanium under the proper conditions. See also ARGON. [Pg.1013]

Laser ablation This method is used as a microchemical sampling procedure for locaHzed determinations. A pulsed neodymium-yttrium aluminum garnet (Nd-YAG) laser is used to ablate material from solid samples. Repetitive laser pulses and sample translation can be used to improve the precision and accuracy of the analysis. Refractory materials and geological samples can be analyzed for trace and major elements. Powdered samples can be pelleted under high pressure for bulk analysis. [Pg.205]

Nd-Yb Neodymium-ytterbium 80 3.4. The high pressure generalized phase ... [Pg.2]

Sihca is reduced to siUcon at 1300—1400°C by hydrogen, carbon, and a variety of metallic elements. Gaseous siUcon monoxide is also formed. At pressures of >40 MPa (400 atm), in the presence of aluminum and aluminum haUdes, siUca can be converted to silane in high yields by reaction with hydrogen (15). SiUcon itself is not hydrogenated under these conditions. The formation of siUcon by reduction of siUca with carbon is important in the technical preparation of the element and its alloys and in the preparation of siUcon carbide in the electric furnace. Reduction with lithium and sodium occurs at 200—250°C, with the formation of metal oxide and siUcate. At 800—900°C, siUca is reduced by calcium, magnesium, and aluminum. Other metals reported to reduce siUca to the element include manganese, iron, niobium, uranium, lanthanum, cerium, and neodymium (16). [Pg.471]

The amide Er NBu (SiMe2H) 3, which has an unexpectedly high vapour pressure, displays three agostic Er H Si interactions in the solid state. Other alkylamides Ln(N-i-Pr2)3 (Ln = Y, La, Nd, Yb, Lu,) are obtained with the less hindered isopropylamide ligand the neodymium compound forms... [Pg.4227]

Oxides. Decomposition pressure measurements on the TbO system by Eyring and his collaborators (64) have been supplemented by similar and related studies on the PrO system (46) and on other lanthanide-oxygen systems (43, 44). Extensive and systematic studies of vaporization processes in lanthanide-oxide systems have been undertaken by White, et al. (6, 188,196) using conventional Knudsen effusion measurements of the rates of vaporization of the oxides into high vacuum. Combination of these data with information on the entropies and Gibbs energy functions of reactants and products of the reaction yields enthalpies of reaction. In favorable instances i.e., if spectroscopic data on the gaseous species are available), the enthalpies of formation and the stabilities of previously undetermined individual species are also derived. The rates of vaporization of 17 lanthanide-oxide systems (196) and the vaporization of lanthanum, neodymium, and yttrium oxides at temperatures between 22° and 2700°K. have been reported (188). [Pg.37]

Vapor Phase Formation and Condensation In order to grow whiskers by vapor phase formation and condensation, the bulk SiC is first vaporized by heating to very high temperatures (>2200 °C), usually under reduced pressure. Upon cooling, a-SiC whiskers form on the nucleation sites. The addition of lanthanum, yttrium, neodymium, or zirconium leads to an increase in the growth rates. However, whiskers are no longer produced commercially using this sublimation process. [Pg.144]

The shape of the curve shown in Figure 56 predicts a fairly high stability of neodymium and promethium dichlorides among the compounds with CN = 9 and dysprosium and thulium dichlorides among the compounds with CN = 7, that is, exactly those lanthanide dichlorides that (except PmCl2) not only were successfully synthesized but also were the subject of some physicochemical measurements that required heating to high temperatures. For instance, saturated vapor pressure of... [Pg.449]

Besides yttrium and neodymium, several studies were also carried out with other R elements, for example in the R-Si-O-N systems by Ohashi et al. (1995). Makishima et al. (1980, 1983) prepared a La-Si-O-N oxynitride glass containing 18 at.% N at 1650-1700°C under high N2 pressure (3 MPa). The glass was transparent and very hard, with a Vickers hardness of 12.0 GPa. [Pg.81]


See other pages where High pressure neodymium is mentioned: [Pg.421]    [Pg.488]    [Pg.947]    [Pg.245]    [Pg.306]    [Pg.285]    [Pg.314]    [Pg.447]    [Pg.448]    [Pg.49]    [Pg.204]    [Pg.271]    [Pg.467]    [Pg.15]    [Pg.423]    [Pg.18]    [Pg.6]    [Pg.18]    [Pg.1874]    [Pg.123]    [Pg.6]    [Pg.295]    [Pg.448]    [Pg.95]    [Pg.63]    [Pg.332]    [Pg.106]    [Pg.2486]    [Pg.316]    [Pg.318]   


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Neodymium

Neodymium vapor pressure, high temperature

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