Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTritriptycene: a D3h C62 hydrocarbon with three U-shaped cavitiesAbdollah. Bashir-Hashemi, Harold. Hart, and Donald L. WardCite this: J. Am. Chem. Soc. 1986, 108, 21, 6675–6679Publication Date (Print):October 1, 1986Publication History Published online1 May 2002Published ini…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElastic modulus of isotactic polypropylene in the crystal chain direction as measured by x-ray diffractionChie Sawatari and Masaru MatsuoCite this: Macromolecules 1986, 19, 10, 2653–2656Publication Date (Print):October 1, 1986Publication History Published online1 May 2002Pub…
Abstract The rapid rise in the popularity of the McCrone Micronizing Mill for sample preparation in routine quantitative analytical x‐ray powder diffractometry (XRPD) has led to the present examination of material obtained with the device and a comparison with material produced by the widely used Tema Mill. Specimens…
The teeth of the sea urchin Lytechinus variegatus grow continuously. The mineral phase, a high magnesium calcite, grows into single crystals within numerous compartments bounded by an organic matrix deposited by the odontoblasts. Electron microscopic examination of glutaraldehyde-fixed Ethylene Diamine Tetra acetic ac…
Abstract An X-ray powder diffraction study of a vermiculitized chlorite in an amphibole schist near Limoges, France, shows the following weathering sequence: chlorite → ordered interstratified chlorite/vermiculite → vermiculite. Mössbauer spectroscopy indicates that vermiculitization proceeded by the release of ferrou…
In a chiral smectic C liquid crystal, a bend type deformation of the C-director induces a polarization charge. We have shown that due to the screening effect by impurity ions the free energy of the electrostatic interaction of the polarization charge is renormalized into the distortion free energy density associated w…
A new method for obtaining thin films of doped molecular materials in a complete absence of oxygen is described. It consists in simultaneously subliming under vacuum the electroactive compound—a metallophthalocyanine—and the electron acceptor or electron donor doping agent. The extent of doping is controlled by the re…
Abstract The heat denaturation of pepsinized bovine nonfibrillar and fibrillar collagen was studied by differential scanning calorimetry. For fibrillar preparations that had been rapidly precipitated with stirring at low ionic strength, then resuspended at physiological ionic strength, multiple denaturational transiti…
Lyotropic nematic mesophases doped with different concentrations of ferromagnetic grains are observed in a polarizing microscope. A minimum concentration of the grains is obtained above which a collective behavior of the nematic matrix is observed. The results are discussed in terms of the elastic continuum theory of…
Abstract The clay and bulk mineralogy of soil and till from 26 Adirondack watersheds was studied. The materials consist typically of quartz, K-feldspar, plagioclase, mica, vermiculite, and kaolinite. Talc, smectite, halloysite, and hornblende are present in some samples. The clay fraction of the soils is composed pred…
1-Aminocyclopropane-1-carboxylate (ACC) synthase (EC 4.4.1.14), extracted from tomato pericarp tissue, was purified 6500-fold by conventional and high-performance liquid chromatography. Two-dimensional gel electrophoresis of this preparation indicated that ACC synthase activity was associated with a protein band at 50…
Interactions between homogeneous acetate kinase and proteins of the phosphoenolpyruvate:glucose phosphotransferase system (PTS) were studied. The phosphorylation of D-glucose was followed spectrophotometrically using a coupled assay system, and acetate kinase and GTP were found to substitute for phosphoenolpyruvate pr…
It is shown that in fixing the crossed Nicols positions a systematic error must invariably be introduced caused by the parasitic ellipticities of the polarizer and analyzer and the refraction of the light beam by the specimen. A method has been derived by which this systematic error can be removed from the original HA…
Two kinds of novel antithrombogenic polyurethane materials were synthesized. One of them is a polyetherurethane with anionic charges on the film surface, and the other is a polyetherurethaneurea to which heparin was covalently bound. The mechanism of their antithrombogenicity was investigated. The anionic polyetherure…
Abstract The reaction behavior of such bis cyclic‐imino‐ethers as 2, 2′‐bis(2‐oxazoline), which had been proved in the previous paper to be an effective chain extender to couple carboxyl terminals of linear polyesters through addition reaction, has been studied to evaluate their practical applicability as the chain ex…
The location measure of a residue in a globular protein is defined as the number of C alpha atoms surrounding the residue located within a sphere of the radius of 14 A. This quantity is a measure of the exposure of a residue to solvent, and is related closely to the distance from the center of mass of a protein. In th…
Acetate kinase from Salmonella typhimurium and Escherichia coli was purified to electrophoretic homogeneity. The amino acid compositions of both proteins were similar, and the apparent molecular weights were the same, about 40,000 for the putative monomers. The native proteins gave higher molecular weights, suggesting…
The distribution and organization of type I and type V collagens were studied in the embryonic chicken cornea using anti-collagen, type specific, monoclonal antibodies and immunoelectron microscopy. These studies were performed on lathyritic 17-day corneas treated at 4 degrees C or 37 degrees C. At the lower temperatu…
The subsolidus phase relationships in Si 3 N 4 –AlN–rare‐earth oxide (Me 2 O 3 where Me=Nd, Sm, Gd, Dy, Er, and Yb) systems were studied. Solid‐solution regions with the α‐Si 3 N 4 structure were delineated along the Si 3 N 4 –“Me 2 O 3 :9AIN” joins for all of the rare‐earth oxide systems studied. The solubility limit…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAluminum siting in mordenite and dealumination mechanismPhilippe Bodart, Janos B. Nagy, Guy Debras, Zelimir Gabelica, and Peter A. JacobsCite this: J. Phys. Chem. 1986, 90, 21, 5183–5190Publication Date (Print):October 1, 1986Publication History Published online1 May 2002Pub…