Materials Literature
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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.
The interpretation of quantitative assays for leukocyte chemotactic migration is usually made in terms of measurements such as leading front distance, total migrating cells, and leukotactic index. These quantities allow comparison of cellular migration behavior under specified conditions. They are not useful; however,…
It has been demonstrated directly by use of x-ray diffraction that at temperatures below the triple point of bulk ethylene (103.8 K) adsorption of ethylene onto the basal planes of graphite only occurs up to a finite number of molecular layers. Further addition of molecules results in the formation of bulk crystallite…
The use of selected organosilicon compounds for the preparation of silicon based ceramic materials is discussed in terms of processing microstructure-property relationships. The mechanisms operative in the formation of gel derived silicate glasses and glass ceramics are reasonably well understood, but this is not true…
Mössbauer spectra of a polycrystalline form of oxidized chloro-5,10,15,20-tetra(mesityl)porphyrin- atoiron(III) [Fe(TMP)Cl], compound A, were recorded over a range of temperatures (4.2–195 K) and magnetic fields (0–6 T). These spectra of compound A exhibit magnetic features which are markedly different from those of t…
The first study of the atomic structure of Si chalcogenide glasses is reported. The Raman spectra are remarkably simple and can be understood in terms of the vibrations of a bitetrahedral ${\mathrm{Si}}_{2}{({X}_{\frac{1}{2}})}_{8}$ ($X=\mathrm{S},\mathrm{S}\mathrm{e}$) unit. The present results represent the most com…
The nucleotide sequence of a 1,163-base-pair fragment that encodes the entire thyA gene of Escherichia coli K-12 was determined. The strategy involved sequence determination of both DNA strands by using overlapping deletions that had been generated in vitro from the two ends of the fragment with BAL-31 nuclease. The a…
The thermodynamics of a system of identical electrically charged spheres in colloidal suspension in a polar fluid (typically, H2O), are calculated within a model of point particles interacting via a screened Coulomb (Yukawa) potential of suitably renormalized strength. The particles are taken to be sufficiently massiv…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMesophase formation and chain rigidity in cellulose and derivatives. 1. (Hydroxypropyl)cellulose in dimethylacetamideG. Conio, E. Bianchi, A. Ciferri, A. Tealdi, and M. A. AdenCite this: Macromolecules 1983, 16, 8, 1264–1270Publication Date (Print):August 1, 1983Publication…