Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA New Type of Divalent Niobium Compound: The First Nb−Nb Triple Bond in a Tetragonal Lantern EnvironmentF. Albert Cotton, John H. Matonic, and Carlos A. MurilloView Author Information Laboratory for Molecular Structure and Bonding and Department of Chemistry, Texas A&M…
▪ Abstract Optimal design of the fiber-matrix interface in ceramic-matrix composites is the key to achieving desired composite performance. In this paper the interface-controlling parameters are described. Techniques for measuring interfacial properties are reported. Examples of interface design of both oxide and non-…
SAXS and TEM measurements are employed in order to study the morphology of poly(styrene)- block -poly(ethene- co- but-1-ene)- block -poly(styrene) (SEBS) with 29 wt % styrene (Kraton G1652) in bulk and at interfaces to different polymers. Temperature-dependent SAXS measurements of the SEBS bulk sample reveal that PS c…
Free-standing ultrathin films of a porphyrin homopolymer have been synthesized by interfacial polymerization of a mercaptoporphyrin. Coupling of 5,10,15,20-tetrakis(α-mercapto- p -tolyl)porphyrin at the water/chloroform interface by copper acetate yields continuous, flexible films after drying with supercritical CO 2…
Like many other prokaryotes, the photosynthetic bacterium Rhodobacter capsulatus produces high levels of polyhydroxyalkanoates (PHAs) when a suitable carbon source is available. The three genes that are traditionally considered to be necessary in the PHA biosynthetic pathway, phaA (beta-ketothiolase), phaB (acetoacety…
Successive ionic layer adsorption and reaction (SILAR) technique was used to deposit cadmium sulfide (CdS) and zinc sulfide (ZnS) thin films on (100)GaAs. CdS thin films were also grown on ITO-covered glass substrates. Multilayer CdS/ZnS thin films were deposited on glass substrates. The crystallinity of the thin film…
The lattice constant, density, electrical resistivity, activation energy, carrier concentration, mobility and Vickers hardness were studied on rare-earth-substituted nickel–zinc ferrites, with formula Ni0.7Zn0.3Fe1.98R0.02O4, where R = Yb, Er, Dy, Tb, Gd, Sm and Ce. We have found that all the rare-earth ions favor the…
Abstract: The impact damage resistance of Fibre Metal Laminates (FML) is studied. FML is a new family of laminated materials which consist of thin aluminium layers bonded together by intermediate fibrelepoxy layers. Different glass fibre FML variants are compared with A1 2024-T3, and carbodPEI composites. The effect o…
The gene encoding citrate synthase from a novel bacterial isolate (DS2-3R) from Antarctica has been cloned, sequenced and over expressed in Escherichia coli. Both the recombinant enzyme and the native enzyme, purified from DS2-3R, are cold-active, with a temperature optimum of 31 degrees C. In addition the enzymes are…
Abstract Mixtures of nematic 4-cyano-4′-pentylbiphenyl and (R)-2,2′-dihydroxy-1,1′-binaphthyl-condensed fulgide derivatives form stable cholesteric liquid crystalline states. Photochromic reactions of them induced the change of their cholesteric pitch reversibly.
Pyruvate kinase M1, a non-allosteric isozyme, was converted into an allosteric enzyme by replacement of an amino acid in the intersubunit contact. The substitution of Ala-398 with Arg resulted in the pronounced allosteric enzyme. The Hill coefficient and the substrate concentration giving one-half of Vmax for the muta…
Previous studies have shown that both polyester and polyether-based polyurea-urethanes are susceptible to cleavage by hydrolytic enzymes. Furthermore, it has been hypothesized that the degree of hard segment micro-domain formation in polyurethane materials, as well as its structure, influences the ability of enzymes t…
An experimental study is presented of the behavior of a molten contact line under conditions which simulate what happens when a molten droplet touches a subcooled solid, spreads partly over it, and freezes. We restrict our attention to the case where the solid and melt are of the same material and have approximately t…
Ultraviolet-induced densification in fused silica is investigated using birefringence measurements to detect compaction-induced strain. This technique is capable of measuring compaction in the 10 parts per billion range in cm-sized specimens. A universal relation describing ultraviolet-induced compaction is discovered…
A large variety of pure and cobalt‐substituted nickel hydroxides of well‐controlled chemical composition, particle size, and morphology have been prepared and characterized by x‐ray, transmission electron microscopy, electrochemical, and Raman spectrometry studies. The hydroxide particle size and its Co‐substituted co…
Extremely transparent and conductive ZnO:Al thin films were successfully prepared by a photo-assisted metalorganic chemical vapor deposition (photo-MOCVD) technique at a temperature of 140° C using diethylzinc and H 2 O as source materials. The vapor from an aqueous solution of aluminum chloride hydrate ( AlCl 3 (6H 2…
The structures of ${\mathrm{B}}_{12}{\mathrm{As}}_{2},$ ${\mathrm{B}}_{12}{\mathrm{P}}_{2},$ ${\mathrm{B}}_{12}{\mathrm{O}}_{2},$ and ${\mathrm{B}}_{12+x}{\mathrm{C}}_{3\ensuremath{-}x}$ $(0.15<x<1.65)$ may each be viewed as composed of ${\mathrm{B}}_{12}$ or ${\mathrm{B}}_{11}\mathrm{C}$ icosahedra and As-As, P…
Abstract The uniform structure of cellulose, combined with its hydrophilicity, biocompatibility, chirality, and structure‐forming capacity, as well as its broad synthetic potential, make the design of cellulose‐based advanced materials a challenge for polysac‐charide research. The synthesis of new cellulose products w…
A series of chemically modified porous silicas, which can be used in high-performance liquid chromatography (HPLC), were prepared by a two-step modification process. Aminopropyl groups were first attached to the silica surface and subsequently converted to amides via the reaction with appropriate acid chlorides. Chang…
In this paper, the percolation threshold of the carbon black-resin composites is discussed based on the experimental results of the changes in resistivity and relative permittivity for loading carbon black, the electric field dependence of current, and the critical exponent of conductivity. It was found that a formati…