Materials Literature
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The crystal structure of 4,4'-difluorobiphenyl has been determined at different temperatures between 155 and 293 K. This compound is isostructural with biphenyl (P21/a, Z = 2). We have carefully analysed the evolution of thermal motion by refining the translational and librational tensors. At any temperature, the mole…
Abstract Fluorine‐containing polyarylates having inherent viscosities of 0.2–0.8 dL/g were prepared from tetrafluoroisophthaloyl chloride and various bisphenols by low temperature solution polycondensation in chloroform with triethylamine or by two‐phase polycondensation in a dichloromethane‐water or nitrobenzene‐wate…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMolecular and electronic structure of six-coordinate low-spin oxo-bridged dimers formed by the interaction of (.mu.-oxo)bis((phthalocyaninato)iron(III)) with nitrogen basesClaudio Ercolani, Marcello Gardini, Keith S. Murray, Giovanna Pennesi, Gentilina Rossi, and Peter R. Zw…
Given current clinical use of phospholipid bilayer structures (liposomes/vesicles) as nontoxic drug delivery vehicles, we have addressed the possibility of employing the phospholipids themselves as MRI contrast agents. To this end we have synthesized phosphatidylcholine with a nitroxide spin label replacing one methyl…
Cerium activated Y 3 Al 5 O 12 has been grown by liquid phase epitaxy (LPE) from a PbO ‐ B 2 O 3 flux. Cathodoluminescence measurements of ( Y 3 − x Ce x ) Al 5 O 12 show an internal efficiency of 6.5% at the film composition and optimal growth conditions. Numerous lanthanide ions were studied in a series of LPE film…
Various methods of determining the pemeability of textile fabrics to the passage of water vapour have been developed and described. An investigation was undertaken to compare the Canadian General Specifications Board (CGSB) Control Dish Method, the apparatus and method described by Farnworth and Dolhan (the DND Method…
A controllable heat sealing technology, based on blends of DURAFLEX* poly butylene polymer (poly-1-butene) with low density polyethylenes, ethylene-vinyl ace tate copolymers (EVA) and other polyolefins is discussed. A variety of systems are described which provide easy-open or peelable seals on various substrates for…
The air resistance of a fabric is an important factor in determining its various end uses. In this paper the measured air resistance of 140 needle-punched fabrics made from 16 different fibers is investigated. An empirical relationship is fitted to the mea sured air resistance data using stepwise multiple regression a…
Abstract Okhotskite, an Mn 3+ -dominant pumpellyite-group mineral, is monoclinic, A 2/ m, a = 8.887, b = 6.000, c = 19.55 Å, β = 97.08°, Z = 1. The formula is (Ca 7.63 Na 0.17 K 0.01 ) Σ7.81 (Mn 2.75 2+ Mg 1.10 ) Σ3.85 (Mn 4.50 3+ Al 1.87 Fe 1.61 3+ Ti 0.02) Σ8.00 Si 12.13 O 39.71 (OH) 16.29 , which simplifies to Ca 8…
Abstract Current understanding of the origin of illite cements within the pore systems of sandstone reservoirs is at best speculative whilst knowledge of the control of illite morpholoy is, to all practical purposes, non‐existent. This is unfortunate considering the widespread occurrence of illite and the often disast…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMeasurement of .gamma..infin. using GLC. 2. Results for the stationary phases N-formylmorpholine and N-methylpyrrolidoneUlrich Weidlich, Hans Juergen Roehm, and Juergen GmehlingCite this: J. Chem. Eng. Data 1987, 32, 4, 450–453Publication Date (Print):October 1, 1987Publicat…
Biomaterials are materials that are used in medical devices that are intended to interact with biological systems. These medical devices include the now common hip replacements and prosthetic heart valves, and the less common neurological prostheses and implantable drug delivery systems. Biomaterials include the tradi…
The theory of magnetic hardening and its impact on the design of permanent magnets is presented. The statistical theory of domain-wall pinning by sample inhomogeneities is outlined, and its relevance to the latest generation of permanent magnets is discussed.
Abstract A review of recent experimental and theoretical results exploring the free‐radical termination process in low conversion polymerization systems is presented. This very interesting and very specific, bimolecular termination step is vital in the development of free‐radical polymerization kinetics and is frequen…
The infrared spectra over the range 4000–150 cm −1 of Cu 4 (OH) 6 (NO 3 ) 2 along with site group and factor group analysis are reported for the first time. The observed absorption frequencies associated with OH and NO 3 modes show distinct individual spectral features in the unannealed and annealed Cu 4 (OH) 6 (NO 3…
Ash and silica contents and depositional patterns were determined for different tissues of 11 plants growing in the southeastern and central parts of the USA. Silica content was high in the leaves, sheaths and inflorescences of the grasses studied, especially so in the inflorescence of the C3 grass, Stipa comata Trise…
The effect of the addition of Bi and Mn on the photoluminescence from ZnO ceramics has been investigated. The effect of the presence of impurities on the green luminescence band can be compared to the effect of oxidizing treatments. A narrow green band has been observed in Mn-doped samples.
After an introduction to quasi crystals, special attention is paid to icosahedral Al 6 (Cr 0.7 Fe 0 . 3 ) and decagonal Al 7 (Mn 1−x Fe x ) 2 . These alloys have been studied with Mössbauer-effect spectroscopy and diffraction techniques. Isomer-shift and quadrupole-splitting data on the icosahedral alloys are successf…
Abstract The Outokumpu region of Finland is notable for the large number of Cr-rich silicate and oxide phases associated with the massive sulphide deposits. In this paper analyses of Cr-rich phases in the epidote-clinozoisite and muscovite groups are presented. The muscovite-type phase shows a maximum 80% substitution…
The elastic moduli of polyelectrolyte liquid crystals are calculated within the second virial approximation. A quantitative numerical and analytical theory is set up for rod-like polyelectrolytes in excess salt, whereas qualitative relations are discussed for polyions under more general circumstances. Electrostatic in…