Materials Literature
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The effects of oxygen partial pressure ( P o2 ) on the oxidation behavior and room‐temperature flexural strength of sintered α‐SiC were investigated. Groups of flexure bars were exposed at 1400°C to flowing Ar containing various levels of oxygen ( P o2 ranging from 7.5 × 10 −7 to 1.5 × 10 −4 MPa). The changes in weigh…
The meaning of “low activation” is quantified with regard to accident safety for naturally occurring elements from hydrogen through bismuth. The activation inventory from a 5 MW/m2 neutron flux for a 4-yr exposure at the first wall to a deuterium-tritium plasma was used for four figures of merit (FOM):1. prompt dose r…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGas-phase reactivity of metal alloy clustersA. C. Harms, R. E. Leuchtner, S. W. Sigsworth, and A. W. Castleman Jr.Cite this: J. Am. Chem. Soc. 1990, 112, 14, 5673–5674Publication Date (Print):July 1, 1990Publication History Published online1 May 2002Published inissue 1 July…
An experimental study of the indentation cracking behaviour of thermally tempered soda-lime glass flats is described. The indenters were steel and tungsten carbide spheres of radii in the range 0·5 to 2·5 mm and a Vickers diamond pyramid. They were loaded normally on to the flats and particular attention was paid to t…
Removal of nucleic acids from cell extracts is a common early step in downstream processing for protein recovery. We report on the precipitation of nucleic acids from a homogenate of Saccharomyces cerevisiae by addition of the cationic polyelectrolyte poly(ethyleneimine) (PEI), focusing on the effect of PEI dosage on…
The in vivo pharmacokinetics and the biodistribution of superparamagnetic iron-oxide particles (AMI25, Advanced Magnetics, Cambridge, MA) were investigated in anesthetized rats. Four different dose concentrations, ranging from 49.8 to 408.9 mumol of Fe (or 2.78-22.84 mg Fe) per kilogram, radiolabeled with 6.0 microCi…
Abstract Sorption of N 2 , O 2 , Ar, CH 4 , CO 2 , C 2 H 4 , and C 2 H 6 in poly (dimethyl siloxane) liquid and rubber and the dilation of the polymers due to sorption of the gases are studied at 25°C under pressures up to 50 atm. In the liquid, the sorption isotherms for low‐solubility and high‐solubility gases are d…
As part of a project examining various magnetic nondestructive evaluation (NDE) methods for residual stress that might be applied to low-carbon structural steels, some magnetization characteristics of 0.13%-C steel are presented for a range of applied fields and stresses. The range of stresses is uniaxial to 160 MPa (…
La spectrometrie IR a transformation de Fourier est un bon outil pour l'analyse des mousses en polyurethanne
Highly reactive, pyrophoric forms of magnesium with specific surface areas of 20–109 m 2 /g (Mg * ) can be generated by the dehydrogenation of catalytically prepared magnesium hydride (MgH 2 * ) or by decomposition of magnesium anthracene · 3 THF ( 4 ). The decomposition of 4 , with recovery of anthracene and THF, may…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrochemically deposited polythiophene. 1. Ohmic drop compensation and the polythiophene paradoxMiklos. Gratzl, Duan Fu. Hsu, Andrew M. Riley, and Jiri. JanataCite this: J. Phys. Chem. 1990, 94, 15, 5973–5981Publication Date (Print):July 1, 1990Publication History Publish…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInfluence of different organic side groups on the thermal behavior of polyphosphazenes: random chain cleavage, depolymerization, and pyrolytic cross-linkingHarry R. Allcock, Gayann S. McDonnell, Geoffrey H. Riding, and Ian MannersCite this: Chem. Mater. 1990, 2, 4, 425–432Pu…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLiquid-crystalline polyethers based on conformational isomerism. 10. Synthesis and determination of the virtual mesophases of polyethers based on 1-(4-hydroxyphenyl)-2-(2-methyl-4-hydroxyphenyl)ethane and .alpha.,.omega.-dibromoalkanes containing from 17 to 20 methylene unit…
A novel compound formed by copper(I1) and a nitronyl nitroxide stable radical of formula Cu(hfac),NITiPr (hfac = hexafluoroacetylacetonate; NITiPr = 2-isopropyl-4,4,5,5-tetramethyl-4,5-dihydroI-H -imidazolyl-1 -oxy1 3-oxide) has been synthesized. It crystallizes in the monoclinic system, space group P2,/c with u = 13.…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSelective hydroxylation of methyl groups by platinum salts in aqueous medium. Direct conversion of ethanol to ethylene glycolJay A. Labinger, Andrew M. Herring, and John E. BercawCite this: J. Am. Chem. Soc. 1990, 112, 14, 5628–5629Publication Date (Print):July 1, 1990Public…
Abstract 2‐Allyloxymethyl‐2‐ethyltrimethylene carbonate ( 1 ) was polymerized in toluene with sec ‐butyllithium as initiator. The resulting product exhibits a bimodal molecular weight distribution. The low‐molecular‐weight fraction consists mainly of cyclic oligomers and to a minor portion of acyclic oligomers. With 2…
Carbon films containing nitrogen and/or boron were prepared in a closed system by the pyrolysis of appropriate precursor materials. The decomposition products of the pyrolysis were identified and the resulting films were characterized by chemical and physical means. The electrical conductivity of the heteroatom‐contai…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAdsorption equilibrium of toluene from supercritical carbon dioxide on activated carbonChung Sung Tan and Din Chung LiouCite this: Ind. Eng. Chem. Res. 1990, 29, 7, 1412–1415Publication Date (Print):July 1, 1990Publication History Published online1 May 2002Published inissue…
The design of a fusion reactor blanket based on a bed of lithium-containing ceramic pebbles or a mixture of ceramic and metallic pebbles requires knowledge of the effective thermal conductivity of such beds. Binary mixtures of spheres with the same diameter but different conductivities as well as beds formed by one ty…
The effects of a substitution for Cu by other 3d metals (Ni, Co, and Zn) on ${\mathit{T}}_{\mathit{c}}$ in the Nd-Ce-Cu-O system was studied and compared with effects of the same ions on ${\mathit{T}}_{\mathit{c}}$ in the La-Sr-Cu-O system. We found (1) Zn suppresses ${\mathit{T}}_{\mathit{c}}$ more slowly in the Nd t…