Materials Literature
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Abstract The hyper‐Raman spectra of SrTiO 3 were studied in the range 85–710 K. The temperature dependance of frequencies and damping of all the vibrations, including the soft F 1u and silent F 2u modes, was obtained. Using the hyper‐Raman spectra and a Green's function analysis, we calculated the damping function Γ s…
The electrohydrodynamic domain patterns observed in freely suspended layers of nematic liquid crystals with negative dielectric anisotropy are investigated. Two different domain patterns, in low and high frequency electric fields, occur. Both the director lines and the hydrodynamic flow lines associated with these pat…
Abstract The phase behaviour of cellulose tricarbanilate (CTC) in ethyl methyl ketone (MEK) solutions was studied in the concentration range of 0,2 – 0,8 g/ml as a function of the temperature. By analyzing the textures in the polarizing microscope and by differential scanning calorimetry experiments several different…
The time during which newly installed or cleaned heat transfer surfaces remain free of fouling deposits thick enough to diminish heat transfer coefficients or energy efficiency is often called the “induction period,” a term disguising lack of knowledge of the microfouling events actually occurring. Using novel flow ce…
Abstract Two types of reinforced elastomeric interpentrating polymer network (IPN) were prepared by simultaneous polymerization and crosslinking in solution. The first type consisted of polyurethane‐poly(methyl methacrylate) (PU/PMMA), and the second, of polyurethane‐poly(methyl methacrylate‐methacrylic acid) PU/P(MMA…
Abstract Identification of the free radicals in polyethylene and nylon produced by irradiation, grinding, and pulling to fracture was carried out by comparing the experimentally observed spectra with the spectra constructed from theoretical consideration with the aid of a computer. It was demonstrated that the various…
Abstract Mit Festkörperreaktionen wurden Einkristalle von NiNb 2 O 6 präpariert und röntgenographisch untersucht. C‐NiNb 2 O 6 (Columbitstruktur) a = 14,032; b = 5,687; c = 5,033 Å, Raumgruppe D —Pben; R‐NiNb 2 O 6 (Rutilstruktur) a = 4,710; c = 3,038 Å, Raumgruppe D —P4 2 /mnm. Ni 2+ und Nb 5+ besetzen im Rutilgitter…
The presence of axial screw dislocations in almost all of the chalcotrichite whiskers of square cross section indicates that they formed by a spiral growth mechanism, thus accounting for their extreme elongation. Ribbon-shaped whiskers are also present. Growth conditions (temperature, pressure, vapor composition, degr…
A series of polyester-based polyurethanes were prepared using polycaprolactone diols and triols of different molecular weights and 4,4′-diphenylmethane diisocyanate and 1,4butanediol. Samples of differing percent of hard segment (0, 23, and 43 %) and different molecular weight of macroglycol were made. Crosslinked pol…
Abstract Monochromatization of Ag Lα X‐rays is achieved by fitting an Ag anode to a conventional Al Kα monochromator. Many new XPS lines are generated by this high energy source including the 1s and KLL Auger series from Al to Cl. Chemical state determination by means of the Auger parameter for these elements is great…
"The Physical Principles of Heat Pipes." Nuclear Technology, 62(2), p. 243
Abstract The intermolecular interaction, IMI, leading to the compatibility of polystyrene, PS, and poly (2,6‐dimethyl‐1,4‐phenylene oxide), PPO, has been identified by analyzing the IMI of the model compounds of low molecular weight; cumene, styrene oligomer, 2,6‐dimethyl phenol, and its trimer. The IMI has been detec…
Abstract A group of rodlike polymers soluble only in strong protic acids was studied using light scattering and viscosity techniques. These include poly(1,4‐phenylene benzobisoxazole), poly(1,4‐phenylene benzobisthiazole) and poly(1,4‐phenylene terephthalamide). The solution properties were dependent on the ionic stre…
Unit cell dimensions are a = 9.463(1) angstrom, b = 12.305(1) angstrom, c = 3.0727(6) angstrom, Z = 4, space group Pbam. The final coordinates gave R = 0.054 and omega R = 0.029 for 614 structure amplitudes and R = 0.030, omega R = 0.027 for 461 amplitudes greater than 2sigma (F).--Modified journal abstract.
Abstract Laser-photolysis studies have been carried out on a solution of 9-diazo-10,10-dimethyl-10-sila-9(10H)-anthracene in cyclohexane. In aerated solutions, the triplet 10,10-dimethyl-10-silaanthracen-9(10H)-ylidene was quenched with oxygen (kq=2×109 M−1s−1) to give a characteristic absorption (λmax at 425 nm) due…
It is shown that, for transition-metal trichalcogenides Nb${\mathrm{Se}}_{3}$, for Ta${\mathrm{S}}_{3}$ both with a monoclinic and an orthorhombic unit cell, and for transition-metal tetrachalcogenide ${(\mathrm{T}\mathrm{a}{\mathrm{Se}}_{4})}_{2}$I, compounds which exhibit transport properties associated with charge-…
Abstract 57 Fe Mössbauer spectra of a cleaned Weipa, Australia, kaolin showed that a considerable fraction of the structural iron exhibits paramagnetic relaxation between 4°K and 300°K, the first time that this has been observed for ferric ions in a mineral. The sample also contained a very fine particle ferric oxide/…
The crystal structure of the title compound, [CO(C15H11N3)2] 12.2H2O, has been determined by single crystal X-ray diffraction methods at 295 K and at 120 K, being refined by least squares to residuals of 0.051 and 0.035 respectively for 982 and 1024 'observed' reflections at these temperatures. Both structures are bas…
Fused mullite, pure and with 10 to 25 vol% ZrO 2 added, was milled in an attritor and sintered in air at temperatures near 1600°C to a dense fine‐grained ceramic. The ZrO 2 promoted densification and retarded grain growth of the mullite phase. Transmission electron microscopy showed that compositions containing ZrO 2…
The energy-loss distribution for pions and protons, with momenta between 0.7 and 115 GeV/c, has been measured in an ion-implanted detector of 300 \ensuremath{\mu}m thickness. The data are well described by an empirical energy-loss distribution.