Materials Literature
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Via computer simulation, we have studied the characteristics of the ‘‘top-hat’’ electrostatic analyzer, which has in principle a 360° field of view in the acceptance plane. Explicit details are given on how the simulation calculations were done. A finite-difference method employing a polar mesh was used for the comput…
La cellulose provenant du papier de qualité chromatographique et incorporant des quantités diverses de carbonates et/ou d'hydrates d'éléments alcalins ou alcalino-terreux, a été soumise à un vieillissement dans des environnements secs et humides, à des températures allant de 60°C à 105°C. Les valeurs du pH extractif,…
Using coupled-mode theory, the coupling coefficient was calculated for a trapezoid grating, and it was shown that it is possible to adjust its shape to obtain a high coupling coefficient. This is one of the advantages offered by the ion beam etching technique.>
The optical antipodes of N-methyletioporphyrin I were resolved and characterized as the zinc complex with a chiral axial ligand by n.m.r. spectroscopy.
Hydrogen treatment of optical fiber waveguides with pure silica cores and boron, fluorine codoped silica claddings was found to effectively reduce the y-ray induced loss increases in visible wavelength region. Germanium-doped core fibers free from metal impurities had good resistance against y-rays. The induced losses…
A tutorial on resistive infinite electrical networks at an undergraduate level is presented. Rather than presenting a comprehensive survey on the wide variety of results existing in this subject, the author introduces the basic ideas with several examples and puzzles, examines how the theory branches into two separate…
A study is made of the fundamental parameters involved in the production of certain fancy yarns. It is shown how use of these parameters enables an existing fancy yarn to be reproduced without resorting to empirical methods and new yarns exhpirical special pre–selected effects to be created. The method developed is th…
Iridium oxide hydrosols, containing both IrIII and IrIV sites within a complex oxyhydroxide structure, have been prepared and their interaction with water-soluble zinc porphyrin radical cations has been studied. The colloids possess a negative surface charge so that the positively charged zinc porphyrins are bound to…
Abstract The effectiveness and efficiency of nine different natural oils were investigated using simulated fermentation media and several dimensionless coefficients were derived to provide a means for quantitative comparison. Furthermore, correlations between the physical and chemical properties of natural oils and of…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTransannulation route to the [5.5.5.7]-fenestrane ring system of laureneneGoverdhan Mehta and Kasibhatla Srinivas RaoCite this: J. Org. Chem. 1988, 53, 2, 425–427Publication Date (Print):January 1, 1988Publication History Published online1 May 2002Published inissue 1 January…
I. INTRODUCTION Roughly 20% of thermoanalytical publications deal with reaction kinetics or contain reaction kinetic evaluations.1 Unfortunately, a great portion of these publications have presented contradictory or meaningless results, which induced a great deal of pessimism about the applicability of reaction kineti…
Abstract
The smooth surface of crystalline poly(ethylene terephthalate) films is readily roughened by ablative photodecomposition obtained by absorption of the pulsed far-UV radiation of the excimer laser. The amplitude of this roughness (of the order of 1 μm) is controlled by the intensity of the pulsed radiation and by the n…
We have found a wide occurrence of alpha,beta-diaminopropionate ammonia-lyase in bacteria and actinomycetes. Considerable amounts of this enzyme were found in Salmonella typhimurium. The enzyme was purified and crystallized from S. typhimurium (IFO 12529). The relative molecular mass of the native enzyme, estimated by…
Abstract The incorporation of a poly[ferrocene‐1, 2 (1, 3: 1, 1′)diylmethylene] fraction with M̄ n =2100 as a smoke suppressant additive into both unplasticized and di(2‐ethylhexyl)phthalate‐plasticized, calcium carbonate‐filled poly(vinyl chloride) (PVC) compositions entails appreciable reductions in smoke evolution…
The authors examine the problems involved in the application of the Maxwell stress equations for finite-element force calculations on magnetised ferrous cores. They also study the effect of the tangential magnetic field strength H/sub t/ on the accuracy of the force calculation. An effective H/sub t/ value is presente…
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We report the observation of an optically isotropic phase in the new disc-like mesogen 2,3,7,8,12,13-hexa(octadecanoyloxy)truxene. On cooling, this optically isotropic phase goes over into a nematic phase, while on heating a columnar phase grows in. To our knowledge this is the first example of a pure discotic mesogen…
The chemical compensation of p-type conducting polymers by ammonia gas can occur by several mechanisms, which lead to products of very different quality.
Abstract The influence of the removal of various diluents, pore forming agents from the porous styrene‐ethylstyrene‐acrylonitrile‐divinylbenzene copolymers on the structure of the matrix was investigated by several methods. The most advantageous pathway to preserve the initial structural edifice of the porous networks…