Materials Literature
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Abstract By the use of thermal volatilization analysis (TVA), 292°C was chosen as a suitable temperature for a preliminary experimental survey of the thermal degradation of styrene–acrylonitrile copolymers. TVA also indicated that there is no fundamental change in reaction mechanism as the acrylonitrile content of the…
The most achromatic quarterwave plates appear to be rhomb-type devices. General relations are given for calculating the phase retardation of these devices and are used to determine the variation of the phase retardation with wavelength and with acceptance angle for different rhomb designs. Length-to-aperture ratio, be…
Magnetic properties of manganese compounds with C1 b -type crystal structure are studied. CuMnSb (lattice parameter a =6.09 5 Å) is antiferromagnetic with a Néel temperature of 55°K and an asymptotic Curie temperature of -160°K. The paramagnetic Bohr magneton number per Mn is 5.4 7 . PdMnSb ( a =6.24 6 Å) is ferromagn…
It is shown by transmission electron microscopy that a rather obvious distinction exists for the interfacial free energies of high-angle grain boundaries, low-angle grain boundaries, and twin boundaries in f.c.c. metals and alloys. The characteristics of these differences are analysed, and a balance of interfacial fre…
A model has been developed to describe the kinetics of void growth in metals during irradiation which explicitly includes the presence of both migrating interstitials and vacancies. It is clear that void growth can occur only when an excess flux of vacancies arrives at the void surface and this can be achieved by taki…
The thermal effects of different types of void volumes within a fuel pin, such as porosity, central void, and the gas gap between fuel and clad are examined. A new general relation for the dependence of thermal conductivity on the closed porosity is deduced. For given gas contents and specific ranges of pore temperatu…
Arrays of gas bubbles of uniform size are generated in a liquid and subjected to sound at a frequency of 30 kHz. In a viscous mixture of glycerine and water, sonoluminescence is produced in the absence of cavitation noise or streamer activity. Under relatively low amplitude conditions the light occurs in flashes with…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCatalytic effect of metal oxides on thermal decomposition reactions. II. Catalytic effect of metal oxides on the thermal decomposition of potassium chlorate and potassium perchlorate as detected by thermal analysis methodsWinfried K. Rudloff and Eli S. FreemanCite this: J. P…
Small- and wide-angle X-ray investigation of drawing and annealing of polypropylene quenched films in wide ranges of draw ratio (λ = 1-20) and of temperature (20°-150°C) shows the discontinuity of the elementary act of transformation in the microneck of the original lamella of the microspherulitic into the microfibril…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSilyl-proton exchange reactionsJohann F. KlebeCite this: Acc. Chem. Res. 1970, 3, 9, 299–305Publication Date (Print):September 1, 1970Publication History Published online1 May 2002Published inissue 1 September 1970https://pubs.acs.org/doi/10.1021/ar50033a003https://doi.org/1…
Electronic transitions in B i–B iv have been studied with the beam-foil technique. Over 100 spectral lines were observed between 450 and 5000 Å. Only half of the lines could be assigned to earlier known boron transitions. Classifications are given for several of the new lines. Mean lives of 33 excited levels in B i–B…
Abstract The rubber phase volume (rubber + occluded polystyrene) can be widely varied in impact polystyrene by controlling the rate of agitation during polymerization. The tensile modulus and magnitude of the rubber phase mechanical loss transitions are related to the degree of polystyrene occlusion. It is shown that…
The lattice parameter of AlAs has been very accurately measured as a function of temperature between 15° and 840°C, and the coefficient of thermal expansion has been determined. The lattice parameter at 0°C is 5.6605±0.0005 Å and the coefficient of thermal expansion is (5.20±0.05) ×10−6/°C. A comparison is made to GaA…
Resistivity and magnetoresistance data obtained from 77 to 700 °K are presented. These data suggest an interpretation based on a strongly spin-polarized conduction band. A model is developed based on this interpretation which can consistently describe the present data and previously published data.
Abstract High‐density commercial polyethylenes have been crystallized under the combined orientation and pressure effects available in the Instron capillary rheometer. The samples so formed were found to have a high degree of crystal perfection and crystal orientation in combination with the unusual property of transm…
Fresh UN powder of a medium particle size (0.3 m2/g) prepared by nitridation of U powder was exposed to O2 at room temperature in a constant volume apparatus. Oxidation was followed by pressure measurement. Under O2 pressures higher than 3 mmHg the powder ignited instantaneously, probably due to local heating in the s…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTJOINT COMMITTEE ON POWDER DIFFRACTION STANDARDSCite this: Anal. Chem. 1970, 42, 11, 81APublication Date (Print):September 1, 1970Publication History Published online23 May 2012Published inissue 1 September 1970https://doi.org/10.1021/ac60293a779RIGHTS & PERMISSIONSArticle Vi…
One of the major problems associated with the use of substituted benzylideneaniline type liquid crystals is their relative instability to cleavage or reaction of the anil linkage. Many workers have noted the presence of ubiquitous impurities in these materials which influence the reproducibility of the phase transitio…
Abstract Ionic conduction in polymer films is of two types. Inverse conduction, I , occurs when the resistance runs counter to that of the external solution, and Direct conduction, D , when the resistance follows that of the external solution. The distribution of areas having D properties has been established for film…
Cathodoluminescence (CL) and x-ray emission excited by an electron microprobe in In1−xAlxP at ∼300°K have been monitored simultaneously to yield conduction band structure and alloy composition, respectively. Efficient single-line CL, characteristic of direct bandgap recombination, is observed for x between 0.0 and alm…