Materials Literature
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In the hydrostatic theory of liquid crystals, we characterize those orientation patterns which may occur, in the absence of externally applied body forces, no matter what the form of the stored energy function may be. It turns out that there are three types of such patterns. In one, the orientation vector is perpendic…
Abstract A study was made of the influence of selected chain modifiers on both the molecular weight of grafted polyacrylonitrile and the grafting frequency of the starch–polyacrylo‐nitrile graft copolymer. Gelatinized wheat starch was used with ceric ammonium nitrate as the initiator. The organic chain modifiers inves…
In dc cables the resistivity of the insulation is a very important parameter, as it determines the stress distribution and the power losses in the insulation. This paper gives the results of several tests on plane capacitors, from which the steady-state resistivity of four different kinds of paper and impregnants appe…
Abstract Elastomer processing operations are discussed and classified as unit operations. The theory of nonlinear viscoelasticity is applied to processing unvulcanized amorphous rubber and the significance of the maximum relaxation time τ m is emphasized.
Pronounced temperature-dependent transfer of excitation from the Er3+ laser pump levels to lower levels of Er3+ was observed in CaF2:ErF3 single crystals at ErF3 concentrations exceeding 12.5 wt %. Transfer of excitation from Er3+ to Tm3+ occurred when TmF3 was included as a second active constituent of the crystals.…
The reactions of the OH radical with H 2 S and SH ⊖ are very fast (k = 1.1·10 10 and 5.4·10 9 mole -1 liter sec -1 , respectively). The hydrated electron reacts with H 2 S (1.1·10 10 ) but does not react with SH ⊖ . The rate constant of the reaction CNS+SH ⊖ CNS ⊖ +SH was found to be equal to 9.8·10 8 . Species absorb…
We have investigated the temperature-dependence of the magnetic moment of Cr3P, Mn3P, Fe3P and Ni3P including solid solutions of these compounds with each other. These measurements indicate Ni3P and Cr3P have a temperature-independent Pauli-type paramagnetism. Mn3P is antiferromagnetic (TN≈115°K) with a moment of 1.68…
Abstract The rhizospheric activity of coniferous and deciduous tree seedlings grown for a period of 13 months in sand cultures containing biotite (50 to 2µ) as the only source of K and Mg, effected the transformation of biotite to kaolinite. The identity of the kaolinite was established by means of X‐ray diffraction a…
The thermal conductivity of KH 2 PO 4 , KD 2 PO 4 and KH 2 AsO 4 single crystals was measured in the temperature range from 4.5 to 300°K. For all the samples critical changes of the thermal conductivity are found at the Curie temperatures. The conductivity decreases gradually with falling temperature in the paraelectr…
Abstract The infrared absorption spectra of selected crystalline and noncrystalline bands were studied in bulk‐crystallized specimens of linear polyethylene which encompassed the extremely wide density range of 0.92–0.99 g./cm. 3 . The analysis of the data obtained at room temperature yield degrees of crystallinity by…
SUMMARY Three distinct species of the genus Nitzschia, lacking chloroplasts and therefore obligately heterotrophic, were isolated in pure culture from various marine shores. The organisms reproduced rapidly in a defined medium based on an artificial sea water supplemented with mineral nutrients, thiamine and cobalamin…
After almost 30 years of use, grain-oriented silicon—iron remains the most important soft ferromagnetic material where high permeability and low core loss are required. In this paper we show how grain structures which the metallurgist has learned to produce affect permeability at H=10 Oe and core loss at B=15 kG. Devi…
Over the temperature range −180° to 300°C, measurements have been made of the coercivity of 5:1 acicular γFe2O3 particles. Samples of two different lengths, 2000 and 6000 Å, were included in the study. The coercive force is linearly dependent upon two terms, shape (αM) and magnetocrystalline (βK/M). These may be separ…
Well-annealed bulk samples of the intermetallic compound FeRh exhibit a first-order transition from antiferromagnetic to ferromagnetic order on heating near 330°K. Plastic deformation has been found to convert the normal CsCl-type ordered structure of FeRh to a disordered fcc structure, which is only weakly magnetic a…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystal structure of potassium permanganateGus J. PalenikCite this: Inorg. Chem. 1967, 6, 3, 503–507Publication Date (Print):March 1, 1967Publication History Published online1 May 2002Published inissue 1 March 1967https://pubs.acs.org/doi/10.1021/ic50049a015https://doi.org/1…
The magnetic susceptibilities of the dioxide and monocarbide of neptunium have been measured from 4.2 to 350°K. The inverse susceptibility of neptunium dioxide is linear in temperature above 60°K with an effective paramagnetic moment of 2.95 μB. A peak in the susceptibility-vs-temperature curve is observed at 25°K, in…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThermal decomposition of metal O,O-dialkyl phosphorodithioatesJoseph J. Dickert Jr. and Carleton N. RoweCite this: J. Org. Chem. 1967, 32, 3, 647–653Publication Date (Print):March 1, 1967Publication History Published online1 May 2002Published inissue 1 March 1967https://pubs…
Micro-nano plastics originating from the prevalent usage of plastics have raised increasingly alarming concerns worldwide. However, there remains a fundamental knowledge gap in nanoplastics because of the lack of effective analytical ...Plastics are now omnipresent in our daily lives. The existence of microplastics (1…
Graphite thermochemical response tested in simulated environment for use as thermal shield for hypersonic reentry vehicles
PbCrO3 has been synthesized in the high-pressure ``belt'' apparatus from PbO and CrO2 at 1150°C and a pressure in excess of 50 kbar. Single-crystal and powder x-ray diffraction at room temperature show the compound has the cubic perovskite structure with a0=4.00 Å. No deformation of the cubic structure was discerned i…