Materials Literature
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During recent years, various hydantoin based heterocyclic glycidyl amine resins have been developed. In these resins the presence of nitrogen containing heterocycle provides extensive variation in polarity, viscosity and hydrophobicity by the choice of alkyl groups. Most of these resins have low viscosity, high polari…
This paper discusses the use of Rietveld analysis to solve crystal structures of titanyl phthalocyanines. Rietveld analysis is based on whole pattern fitting in which every point in the x-ray powder diffraction pattern is used as a measure of one or more Bragg diffraction peaks. Thus the refinement of relatively compl…
It is shown that fatty acids such as the arrachidic and the lauric acids and their mixtures with cholesterol exhibit nonlinear optical properties. The effects of a 20 mW He-Ne laser (λ= 6328 Å) on such mixtures exhibiting smectogenic mesomorphism were examined and the optical activity dependence on the cholesterol per…
Heat capacities and thermodynamic properties of a number of poly(chlorotrifluoToethylene) samples subjected to various thermal treatments, to achieve crystallinities ranging from approximately 10 to 90%, have been studied from 2.5 to 370 K by automated adiabatic calorimetiy and from 250 to 620 K by differential scanni…
Abstract Three of the six possible stereoisomers of dodecahydroacenaphthylene, t,t,t ‐ufolane ( 1 ), c,c,t ‐ufolane ( 3 ), and c,c,c ‐ufolane ( 5 ), have been synthesized for the first time. The configurations have been confirmed inter alia by an X‐ray analysis of the precursors 11, 14 , and 23 and the bromine adduct…
In situ observation of the growth of isotactic polystyrene has been carried out under a transmission electron microscope. Bundles of lamellar crystals first emerge from the melt, and then a planar crystal parallel to (001) grows out from one end of each bundle. The planar crystal assumes the shape of a hexagon faceted…
Backscattering of radiation incident on a solid medium has been treated with some success as a reflection phenomenon. The concept of albedo has been used in the literature to deal with this problem. A Monte Carlo program has been used in this study to simulate the generation of bremsstrahlung beams from medical linear…
Some effective uses of the radial gradient-index (GRIN) lens in zoom lens systems are presented and lens design examples are shown. Also the effective Abbe number of a cemented GRIN lens is discussed and it is shown that a radial GRIN lens with uncommon dispersion can be replaced by a cemented radial GRIN lens with co…
Abstract Understanding the dynamics of soil K is important for the formulation of a sound fertilizer management strategy. Two experiments were conducted to determine the behavior of K in the soil after fertilization. Five rates of K (0 to 120 kg ha −1 ) were applied to two Typic Paleudults, a loam and a sandy loam, in…
Fouling cannot always be prevented; it is important to consider the design of fouling‐resistant heat exchangers. To examine these exchangers, a test fluid whose fouling behaviour is understood should be used. Experiments have been conducted to examine the response of two model systems, a pulsatile flow and a fluid bed…
Abstract Amorphous Nb 2 O 5 thin films are obtained by vacuum evaporation of high‐purity Nb 2 O 5 powders onto NESA glass substrates. These films were found to exhibit both photochromism and electrochromism. Reasonably good photochromic responses were observed in ethanol and in the N 2 atmosphere, but no photochromism…
The synthesis and nonlinear optical properties of a series of chiral pyrrolo[1,2-a]quinolines la-e is presented. The microscopic hyperpolarizabilities (beta(z)) were determined by EFISH measurements and the macroscopic susceptibilities (X2) were estimated by the Kurtz powder test. A small fixed angle of the annelated…
Comparatively little research has been published on radioactive contamination from nuclear medicine patients using hospital toilet facilities. The present study was undertaken to obtain an estimate of the amount of restroom contamination found in a typical 700-bed community hospital as a result of nuclear medicine pro…
We present the results of a dielectric investigation of two members of the 4-n-pentylphenyl-4′-n-alkyloxythiobenzoate ([nbar]S5) homologous series with n = 9 (9S5) and n = 10 (10S5), in the frequency range 0·1–10 MHz, and in the temperature range covering all of the liquid crystal phases. Some properties of the [nbar]…
Unstable superoxide, · O 2 - , and semiquinone can be stabilized when hydroxyapatite Ca 10 (PO 4 ) 6 (OH) 2 is crystallized from aqueous solutions containing these radicals. The inorganic microcrystals surround the radicals and stabilize them for nearly a year at room temperature. Radicals adsorbed on the surface of a…
A theoretical model describing the behavior of a thermally thin cellulosic sheet heated by external thermal radiation in a quiescent microgravity environment is developed. This model describes thermal and oxidative degradation of the sheet and the heat and mass transfer of evolved degradation products from the heated…
Mullite composites toughened with ZrO 2 (with or without a MgO or Y 2 O 3 stabilizer) and/or SiC whiskers (SiC( w )) were fabricated by hot‐pressing powders prepared from Al, Si, Zr, and Mg(Y) alkoxide precursors by a sol–gel process. Micro‐structures were studied by using XRD. SEM, and analytical STEM. Pure mullite s…
Over the last twenty years, unified viscoplastic constitutive models have evolved to meet this need. These constitutive models provide a means for representing a material's response from the elastic through the plastic range including strain-rate dependent plastic flow, creep, and stress relaxation. Rate-dependent pla…
Abstract Messung der elektrischen Leitfähigkeit von Na 3 O(NO 2 ) und Na 3 O(CN) zeigen, daß beide Verbindungen bei Temperaturen zwischen 200° und 250°C eine sprunghafte Zunahme der Natrium‐Ionenleitfähigkeit aufweisen. Diese Effekte beruhen nicht auf Schmelzprozessen, wie die Phasendiagramme der entsprechenden pseudo…
Discusses the quality of fabrics and garment technology. Looks at the various types of material focusing particularly on the female market. Shows how new synthetic fibres have improved the feel of garments and that consumers, fashion designers and experts in finishing have all reached the same conclusion, that quality…