Materials Literature
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Application of time correlated single photon counting to pulsed Mie scattering enables one to resolve changes in light scattering to better than 50 ps. This technique is applied to the highly nonlinear motion of a sonoluminescing bubble. Physical processes, such as outgoing shock wave emission, that limit the interpre…
Sequence analysis of the recently identified class I aldolase of Escherichia coli (dhnA gene product) helped to identify its homologs in Chlamydia trachomatis, Chlamydiophyla pneumoniae and in each of the completely sequenced archaeal genomes. Iterative database searches revealed sequence similarities between the DhnA…
A thermodynamic description of the Cr-Ti system is obtained by the optimization of the available thermodynamic and phase diagram data. The Redlich-Kister polynomial is used to describe the excess Gibbs energies of the liquid, bcc and hcp phases. The sublattice model is used to describe the different types of Cr 2 Ti L…
Crystalline orientation often provides particularly the anisotropy of chemical and physical properties. Since the epitaxial films are composed of highly oriented crystals, it is expected that chemical and physical advantages are predominantly in one specific direction. In this study, high-rate epitaxy of anatase films…
The internal friction (IF) and the Young’s modulus of SrBi2Ta2O9 (SBT) ceramics were measured by using the reed vibration method in the temperature range from 100 to 600 K with kilo-hertz frequencies. A high IF peak associated with a modulus defect appeared around 500 K, which was assumed to be due to the migration of…
The effect of heat treatment on the properties of Ni-Mn-Ga films such as chemical composition, crystal structure, microstructure and transformation temperature were investigated with respect to various sputtering conditions. Ni-Mn-Ga films were deposited on a poly-vinyl alcohol substrate with a radio-frequency magnetr…
Polyurethane (PU) frequently has been used to manufacture small diameter vascular grafts due to its good bicompatibility. In this study, sponge PU small diameter vascular grafts were fabricated from Pellethane 2103, as well as a self-synthesized PU, by utilization of a salt casting technique and by varying the salt/po…
Dynamic mechanical thermal analysis (DMTA) was used to determine the crosslink density and glass transition temperature of various ceramer coatings. The metal-oxide ceramer coatings were developed using linseed oil as the organic phase with titanium isopropoxide, and zirconium propoxide as the inorganic sol-gel precur…
The eigenmodes of director orientational fluctuations in nematic liquid crystals in confined geometries were studied both theoretically and experimentally by dynamic light-scattering tehnique. The fundamental mode of the orientational fluctuations shows a crossover from bulk behavior, dominated by bulk elastic constan…
Ring-opening polymerization of cyclic dicarbonates, cyclobis(hexamethylene carbonate) (1 a) and cyclobis- (diethylene glycol carbonate) (1 b), and their copolymerization with lactones have been carried out using lipase as catalyst. These carbonates were polymerized by Candida antarctica lipase under mild reaction cond…
The strains determined on polycrystalline materials using X-rays or neutron-rays are averaged values of all those crystallites that, for a given direction of measurement, contribute to the respective interference line. The usual stress evaluation by the sin2ψ-method delivers the mean stress values of the material phas…
Abstract X-ray phase analysis of clays is difficult because these materials generally consist of a mixture of different phases, i.e. , mixed-layer minerals, individual clay minerals (non mixed-layer), and associated minerals, such as calcite and quartz. The analysis requires knowledge that presently is incorporated in…
Geranylgeranyltransferase I (GGTase I) catalyzes the transfer of a prenyl group from geranylgeranyl diphosphate to the carboxy-terminal cysteine of proteins with a motif referred to as a CaaX box (C, cysteine; a, usually aliphatic amino acid; X, usually L). The alpha and beta subunits of GGTase I from Saccharomyces ce…
A series of random copolyesters of reasonably high molecular weight was synthesized with varying composition by melt copolycondensation of dimethyl terephthalate (DMT) with ethylene glycol (EG) and diethylene glycol (DEG). Composition and molecular weight of the copolyesters were determined by 1H NMR spectroscopy and…
The mechanical behavior of plain woven fabric composites under inplane loading is investigated using 3-D finite element analysis (FEA) in conjunction with a micro-mechanical model. The analysis incorporates both geometric and material nonlinearities. The use of finite elements facilitates accurate description of the g…
Farblose Einkristalle von La2(SeO3)3 wurden bei der Zersetzung von La2(SeO4)3 in Gegenwart von NaCl in verschweißten Goldampullen erhalten. Die Verbindung kristallisiert orthorhombisch (Pnma, Z = 4, a = 846,7(1), b = 1428,6(1), c = 710,3(2) pm, Rall = 0,0223). In der Kristallstruktur sind die La3+-Ionen zehnfach von S…
Polyaniline films have been prepared both chemically and electrochemically using formic (‘Pani-Formic’), boric (‘Pani-Boric’) or acetic acid (‘Pani-Acetic’) as protonation media. Among the three, formic acid seems to be a better protonating medium because it selectively yields the conducting phase of polyaniline. The…
A thin film of deuterated poly(methyl methacrylate) (A) and poly(styrene-ran-acrylonitrile) at the critical composition is annealed in the two phase region to induce simultaneous phase separation and wetting of the A-rich phase at the surface. Using forward recoil spectrometry, the wetting layer thickness is found to…
Dielectric studies of the first order phase transition of a ferroelectric liquid crystal material having the phase sequence chiral nematic to smectic C* have been performed using thin (2.5 mum) cells in the frequency range 0.01 Hz to 12 MHz. For planar alignment, one of the cell electrodes was covered with a polymer a…
Copolymers sPS-B consisting of blocks of syndiotactic polystyrene (sPS) and polybutadiene (B) have been prepared using CpTiX3 (Cp = C5H5, X = Cl, F; Cp = C5Me5, X = Me) and TiXn (n = 3, X = acetylacetonate (acac); n = 4, X = O-tert-Bu) activated with methylaluminoxane (MAO). If proper conditions are used, copolymers c…