Materials Literature
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This paper describes tracking and ignition phenomena of distribution cable and sheet specimens of polyvinyl chloride (PVC) resin on the basis of experimental results obtained by a test method conforming to the IEC tracking test method. Also, the processes of tracking associated with the ignition and combustion of PVC…
Abstract Kaolinite is synthesized in approximately the same time in three temperature ranges: (1) from 200–250° to 350–400° (hydrothermal processes); (2) from 120 to 175° (semihydrothermal ones); (3) at ordinary temperature. It is thus evident that the rate process cannot be explained by the Arrhenius equation only, b…
Abstract In‐plane mechanical properties, coefficients of thermal and hygroscopic expansion, and dimensional changes due to stress relaxation were measured as a function of direction in one, three, and five‐mil polyimide films. Although these films were made by a casting process, they exhibited significant anisotropy i…
Abstract The chemical and electrical stabilities of 7,7,8,8‐tetracyanoquinodimethane (TCNQ) salts composed of neutral TCNQ (TCNQ ˆ ), anion radicals of TCNQ(TCNQ − ·), and polycation polymers were studied by measuring their electronic spectra and resistivities (ρ). The results of spectral and chemical analyses confirm…
Résumé Les analyses thermiques (A.T.P. et A.T.D.) de la palygorskite ont été réalisées entre 20 et 900° La palygorskite contient trois types d'eau nettement différenciés par leur rôle dans la structure. Cependant, les analyses thermiques indiquent un chevauchement des domaines de température où ces diverses molécules…
A model for intergranular crack growth is developed in which atoms are deposited preferentially in a zone ahead of the crack tip. The crack remains sharp provided the length of the diffusive plating zone is much larger than the crack width. The crack velocity depends on a high power of the applied stress. Instabilitie…
Abstract Oriented fibers of poly(pentamethylene terephthalate) will crystallize in one of two phases. In one phase (designated α), which is preferred in the unstressed fiber at room temperature, the chain is contracted from its chemical repeat length. In the other (designated β), induced by tension, it is nearly fully…
There has been a growing awareness over the past few years of the great potential of ESCA for investigating polymeric systems in general, and several recent reviews provide extensive background reading.1−3 In this article, there–fore, attention will be focused on the aspects of interest to surface scientists, in parti…
Low-temperature (3.5<T<77 °K) measurements of the dielectric constant and dissipation of ZnO ceramic varistors are presented for frequencies f in the range 30<f<105 Hz. A loss peak and dispersion in ε observed at 4 °K are identified as resulting from the two-phase structure of the ZnO varis…
Abstract The characteristic structural, textural and compositional features of the various kaolinite-rich clayrocks known as flint clay, toasted clay, kaolinite tonstein and bauxitic clay are briefly reviewed together with their mode of occurrence. It is considered that these rocks have much in common; sufficient to w…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCharacterization of some mixed-halide copper(II) dimers of the general formula [Cu2XnX'6-n]2- (X = chloride(1-) and X' = bromide(1])): evidence for the preference of chloride bridges in the mixed-halide speciesWilliam E. Estes, John R. Wasson, James W. Hall, and William E. H…
A simple algebraic method is presented for estimating impedance parameters for electrochemical systems that exhibit pseudoinductance. The method, which makes use of four characteristic points from the complex plane diagram, is illustrated by calculating impedance parameters for transpassive chromium in sulfuric acid.…
ABSTRACT Mytilus edulis could be adapted to salinities between 25% and 125% under laboratory conditions, with complete ionic and osmotic conformity of the body fluids. Extracellular space, intracellular cation concentrations and water content were determined for the cerebro-visceral connectives of Mytilus adapted to e…
Abstract Hg 2 P 2 S 6 kristallisiert triklin mit a = 6,252(3), b = 6,262(4), c = 7,126(6)Å, α = 96,21(6), β = 105,69(6), γ = 119,15(4)° und Z = 1 in der Raumgruppe P 1 ; Hg 2 P 2 Se 6 monoklin mit a = 6,545(3), b = 11,377(3), c = 13,610(5) Å, ß = 98,47(5)° und Z = 4 in der Raumgruppe C2/c. Dei Kristallstrukturen wurde…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystalline beryllium hydrideG. J. Brendel, E. M. Marlett, and L. M. NiebylskiCite this: Inorg. Chem. 1978, 17, 12, 3589–3592Publication Date (Print):December 1, 1978Publication History Published online1 May 2002Published inissue 1 December 1978https://pubs.acs.org/doi/10.10…
Abstract The conformational transition of poly( L ‐agrignine) by binding with various mono‐, di‐, and polyvalent anions, especially with SO , was studied by CD measurements. The intramolecular random coil‐to‐α‐helix conformational transition and the subsequent transition to the β‐turn‐like structure was caused by bind…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT2-(Trichloroacetyl)pyrroles as intermediates in the preparation of 2,4-disubstituted pyrrolesPeter Barker, Paul Gendler, and Henry RapoportCite this: J. Org. Chem. 1978, 43, 25, 4849–4853Publication Date (Print):December 1, 1978Publication History Published online1 May 2002P…
Measurements of the specific heat of FCC iron alloys reveal Schottky anomalies in the paramagnetic temperature range with the same excitation energies of about 0.1 eV that have been used in a preceding paper to describe the anomalies in thermal expansion. Magnetically ordered Fe-Ni alloys also reveal anomalies in spec…
The first series of polymeric liquid crystals with a cholesteric phase has been prepared by copolymerization of the methacrylic esters (1) and (2). Pure poly-(1) forms a nematic phase; the cholesteric structure is induced by the chiral species (2).—Pure poly-(2) is not liquid crystalline.
Following a major shortage of 99Mo in the 2009–2010 period, concern grew that the aging reactor production facilities needed to be replaced. Most producers were using highly enriched 235U (HEU) as the target material. The Organisation for Economic Co-...Read More