Materials Literature
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Abstract Photodegradation of polyurethanes based on polyester diol‐diphenylmethane‐p,′p‐diisocyanate in the absence and presence of various metal acetylacetonates (Ti, V, Cr, Mn, Co(II), Co(III), Fe, Ni, Cu, Zn, Mg, Al, and Sn) was carried out; and the effect of these metal compounds on the degradation was examined by…
Abstract Die bisher unbekannte Verbindung MgCu 2 O 3 wurde dargestellt und mit Einkristalldiffraktometerdaten röntgenographisch untersucht. MgCu 2 O 3 kristallisiert orthorhombisch mit a = 4,00, b = 9,35, c = 3,19 Å; Raumgruppe D –Pmmn und ist mit CaCu 2 O 3 isotyp. Cu 2+ ist verzerrt oktaedrisch von O 2− koordiniert.
Skin samples were removed from several body regions of the pig by biopsy or during the slaughter process and were fixed, processed for paraffin embedding and sectioned at 6 to 8 µm thickness. Several stains were used to emphasize the different structures of the organ. Microscopic observations revealed that the epiderm…
Abstract A new method is presented for the numerical solution of nonlinear minimum‐time control problems where at least one of the state variables is monotone. A coordinate transformation converts the problem with fixed end point and free end time to one of free end point and fixed end time. The transformed problem ca…
The flow figures in the thin films of MBBA under the applied electric field are observed fromthe transverse direction. The aspects of transitions from the Williams domain to turbulence and from the chevron texture to turbulence are different from each other. A new grid pattern is observed in the region between the Wil…
Austenitic stainless steel specimens were subjected to strain cycling using a square strain wave while under potentiostatic control in aqueous solution. Strains of ±0.025 to ±0.05 were employed at an average strain rate of 0.30 sec −1 . The transient dissolution behavior of the steel was investigated at active, passiv…
Several types of commercially available ceramic BeO are evaluated for thermoluminescence and combined thermoluminescence-exoelectron dosimetry (TLD-TSEE). The ceramic Thermalox 995 is superior in nearly all respects. Physical and chemical treatments which enhance or reduce sensitivity and stability of TSEE exert often…
Anodic. behavior of 18Cr-5Ni-10Mn steels containing 0.07 to 0.35% nitrogen was studied in a 0.1N H2SO4 solution with additions of 0.01 to 0.1 N NaCl. The nitrogen content in these steels does not significantly affect their passive behavior but increases their pitting resistance. The most susceptible sites for pit nucl…
The crystal and molecular structures have been determined, by single-crystal X-ray methods, for each of the isomorphous set of divalent binuclear metal derivatives of 1,3-diphenyltriazene, abbreviated as dptH, [M(dpt)2]2 where M = Ni, Pd, and Cu. The crystals are composed of discrete molecular units, of composition M2…
Abstract The effects of diluent on molecular motions and glass transition in the polystyrene–toluene system was studied by means of dielectric, thermal, and NMR measurements. Three dielectric relaxations were observed between 80 and 400°K. On the basis of NMR measurements on solutions in toluene and in deuterated tolu…
By using the 0-lattice formalism of Bollmann, Burgers vectors of intercrystalline boundary dislocations are defined from the knowledge of two near-coincident cells M1 and M2 of lattices 1 and 2. Internal points belonging to M1 and M2 are taken into account to construct the DSC lattices related to the given boundary. A…
Abstract The structural changes in poly(vinyl chloride) during thermal degradation in nitrogen at 190°C have been investigated. From gel permeation chromatography analyses no chain scission, but only crosslinking reactions were observed. An increase in the molecular weight was measured even at 0.3% conversion. For lon…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFactors influencing the stabilities of nematic liquid crystalsMichael J. S. Dewar and Robert M. RiddleCite this: J. Am. Chem. Soc. 1975, 97, 23, 6658–6662Publication Date (Print):November 1, 1975Publication History Published online1 May 2002Published inissue 1 November 1975h…
Domain wall kinetics are studied in glassy iron-base wire and iron-nickel–base ribbon. These materials exhibit high wall mobilities. The wire is examined in a single-wall regime below the nucleation field. Here reversal takes place by propagation of a domain wall of 2.5-cm axial length along the wire. The mobility nor…
The distribution of the nuclei of chromium hexacarbonyl Cr(CO)6 in the crystalline state was refined from neutron diffraction data at 78K. It was found that diffraction by the aluminum walls of the cryostat used for low-temperature measurements was superimposed on the diffraction peaks of the crystal, and a method was…
A comprehensive perturbation formalism is developed in order to relate the rotating-frame spin-lattice relaxation time ${T}_{1\ensuremath{\rho}}$ to the relative motions of the nuclear spins in a crystal lattice. A general relaxation equation valid in the entire temperature region is derived, from which both the stron…
Fourteen year data for 90-10 and 70-30 cupronickel alloys exposed in sea water at the F. L. LaQue Corrosion Laboratory, Wrightsville Beach, North Carolina are reported. Corrosion rates for both alloys in quiet and flowing as well as in the tidal zone tended to become linear after the first 4 years' exposure. Initially…
The refractive index and the absorption coefficient for sputtered α-HgS films several μm thick were determined in the wavelength region from 0.5 to 2.5 μm by the analysis of transmission and reflection spectra. The results showed that the refractive index for as-deposited films decreased with increasing rf power densi…
Abstract Coarse, medium, and fine‐textured soils were studied in three different arid regions of Iran, namely Gazvin, Karaj, and Kooshkak alluvial plains, respectively. Six representative pedons including 33 samples were tested. X‐ray analyses indicated the clay mineral components of soils consist of some discrete ver…
Abstract Thick Bh horizons in siliceous sands of the North Carolina Coastal Plain have essentially no extractable iron, and very small quantities of calcium, magnesium, and potassium. Aluminum is the dominant cation and the exchange properties of the Bh horizons are dominated by Al and organic carbon. One to two grams…