Materials Literature
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For pt.II see ibid., vol.8, p.2389 (1978). The intermetallic compound Fe 3 Sn 2 has been studied by 119 Sn Mossbauer spectroscopy between 5 and 670K. Between approximately 60 and 250K the spins rotate from the basal plane to the c axis; a fraction alpha (T) of the spins remain in the basal plane while the remainder ro…
A material-related model for thermal fatigue is presented and discussed in connection with tool steels in hot-work applications. The model, which is based on ordinary ‘fatigue laws’, includes a simplified stress/strain analysis for the general thermal fatigue case. From this analysis expressions are generated which re…
Abstract Vulcanization is a process which decreases the plastic properties of rubber while maintaining or improving the elastic properties. The term vulcanization has been applied in the past mainly to the reaction of rubber with sulfur, but now is generally used for the process which results in changes in properties,…
Abstract The stress‐strain and impact loading behavior of simultaneous interpenetrating networks (SIN's) based on three elastomers derived from polymerized castor oil and polystyrene was studied. The elastomers included the sebacic acid polyester, the 2,4‐tolylene diisocyanate (TDI) polyurethane, and the mixed sebacic…
ABSTRACT The “double thecae” or “internal septa” of Eunotia soleirolii (Kütz.) Rabenh, are shown to represent the thecae of resting spores, as characterized by their physiology, as well as morphology. They differ from all resting spores of centric diatoms by the formation of both their valves as a result of unequal ce…
The Gurney energy method, an analytical method with which to compute fragment velocity distributions for continuous casing warheads, is reviewed and a method to model velocity losses due to end effects on cylindrical charges and end projector type warheads is presented. The Taylor formula, which estimates the angle of…
Abstract Methods for determining the crystallisation characteristics of polymer by differential scanning calorimetry are discussed, particularly in terms of their limitations. Isothermal and non‐isothermal crystallisation thermogrphs are analysed to determine crystallisation mechanism and compared with other technique…
Abstract Laser Raman spectra of atactic poly(vinyl alcohol) (PVA) after heat treatment and/or swelling in water have been obtained. An amorphous Raman band is observed at 1124 cm −1 , while a crystalline Raman band is found at 1147 cm −1 . A new method for crystallinity determination is proposed, in which the amorphou…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAn electrochemical study of the protonation site of the cobaltocene anion and of cyclopentadienylcobalt(I) dicarbollidesWilliam E. Geiger Jr., William L. Bowden, and Nabil El MurrCite this: Inorg. Chem. 1979, 18, 9, 2358–2361Publication Date (Print):September 1, 1979Publicat…
Summary Na‐Mg and Na‐Ca exchange isotherms were determined at electrolyte concentrations of 500, 50, 5 and 1 meq per litre for illite, vermiculite and montmorillonite and for three soils containing illite and montmorillonite. This enabled comparisons to be made of clay swelling, dispersion and soil hydraulic conductiv…
Contractile properties of an isolated segment of the secretory coil of the monkey palm eccrine sweat gland were studied in vitro with a transducer. Contraction of up to 10 mgf was induced with acetylcholine but not with alpha or beta adrenergic agonists, caffeine, prostaglandin E1, or by a calcium ionophore A23187. Ot…
The vibrational frequencies of Si–H groups, SiH, SiH2, and SiH3, in substituted silane molecules, and hydrogenated amorphous solids, display shifts in frequency that can be correlated with the relative electronegativities of the silicon nearest neighbors, i.e, the substituting atoms or groups in the molecules, and the…
A new series of $^{27}\mathrm{Al}$ hyperfine spectra have been discovered by EPR studies in irradiated type-I and -II vitreous silica. Our analysis of these spectra indicate that under ionizing irradiation at low temperatures ($T\ensuremath{\lesssim}260$ K), pre-existent, diamagnetic network defects of the form $\math…
ADVERTISEMENT RETURN TO ISSUEPREVArticleA New Liquid-Crystalline Material. Transition Metal-Poly(yne) PolymersS. Takahashi, E. Murata, M. Kariya, K. Sonogashira, and N. HagiharaCite this: Macromolecules 1979, 12, 5, 1016–1018Publication Date (Print):September 1, 1979Publication History Published online1 May 2002Publis…
The application and maintenance of outdoor ceramic insulation on overhead transmission systems has been an art learned by experience. This document combines the experiences of electric utilities, manufacturers, and research laboratories into a single comprehensive report on the design and maintenance of transmission i…
Secondary ion mass spectrumètry has been applied for measuring the tracer diffusivity of oxygen in the c direction of single‐crystal rutile for a temperature range of 1150 to 1450 K at 6000 Pa pressure of oxygen gas. Specimens diffusion‐annealed in oxygen gas containing 18 O were subsequently continuously sputtered an…
The magnetic field dependence of the capacitance of a twisted nematic layer has been analysed by Shtrikman et al (1) who found only moderate agreement between their theory and the experimental results of Gerritsma et al (2). Here we investigate the voltage dependence of the capacitance of a twisted nematic liquid crys…
Solutions of octaalkyl metalloporphyrin Π cation radicals react with nucleophiles such as nitrite, chloride, pyridines, imidazole, cyanide, triphenylphosphine, thiocyanate, acetate, and azide, to produce the corresponding meso-(methine) substituted metalloporphyrins. Demetalation then gives the appropriate meso-substi…
A simple and efficient numerical procedure is presented for determining the static charge distribution on arbitrary-shaped surfaces. Surfaces are modeled by planar triangular subdomains in which the charge density is assumed to be constant. The method of moments is employed to calculate the charge distribution on the…
Abstract Polycarbonate tensile bars were aged up to 18 months at 0%, 75%, and 100% relative humidity and temperatures of 65–93°C. In the humid aged samples hydrolysis caused progressive reductions in molecular weight. Below a critical molecular weight ( M w = 33,800, M n = 14,300) tensile strength dropped off rapidly.…