Materials Literature
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Bulk and thin film GexSe1-x alloys have been prepared with 0.1≤X≤0.5.The bulk materials were obtained by quenching from the melt. They have beenused as source materials to produce thin film samples using the thermalevaporation method (semi-closed space technique). The composition of theobtained films was checked again…
The crystal structure and the magnetic state of polycrystalline LaMn 1− x V x O 3 (0.1< x <0.9) compounds have been studied by x-ray and neutron diffraction methods, as well as by magnetization and ac susceptibility measurements. It is shown that substitution of vanadium for manganese ions leaves the orthorhombic crys…
The polymerization of racemic lactide with a racemic aluminum alkoxide catalyst is reported. Microstructural analysis of the polymer produced with 1H NMR spectroscopy revealed that an isotactic stereoblock poly(lactic acid) formed, where each enantiomerically pure block contained an average of 11 lactide monomer units…
Part I provided a detailed description of a model developed to predict the mechanical properties of yarns and cords from single-filament properties. The objective in Part II is to assess the accuracy of the model by comparing predicted results with experimental data. Multifilament PET yams were obtained from various m…
From the stem of CaLotropis procera, olean-12-en-28 oic acid-3-0-a-L-rhamnopyranosyl (J~2) ~-D-glucopyranosyl ( I ~2) !)-D-galactopyranoside 1 and 3-0{ ~D-glucopyranosyl (J ~2)-!)D-glucopyranosyl (J ~6)-~D-glucopyranosyl ( 1~3)-aL-arabinopyranoside) olean-12-en-28-0-~D-glucopyranosyl 2 have been isolated. Their struct…
Palladium and palladium-copper catalysts supported on silica and niobia were characterized by H2 chemisorption and H2-O2 titration. Systems over silica were also analyzed by transmission electron microscopy and EXAFS. The metallic dispersion decreased from 20% to 7% when the content of Pd was increased from 0.5wt.-% t…
Second-harmonic generation (SHG) was observed from thermally poled alkaline earth containing mixed alkali silicate glasses. Since no SHG could be observed in alkaline-earth oxide-free glasses, it was considered that alkaline-earth oxide played a significant role in the generation. The intensity of SHG increased with t…
Three types of organic-inorganic hybrid materials were prepared by the sol-gel processable monomers derived from 3-isocyanatopropyltriethoxysilane with three different hydroxy-functionalized nonlinear optical chromophores. The measured values of NLO coefficient strongly depended on conditions such as poling temperatur…
Surface phenomena which occur in the process of thin yttrium hydride film YH x (0 < x < 2.62−2.80) formation were studied through simultaneous measurements of work function Φ and hydrogen pressure P during H 2 interaction “in situ” with thin yttrium films, deposited under ultrahigh vacuum conditions. These studies wer…
Poliuretanos segmentados formados por segmentos flexíveis e rígidos bem caracterizados foram sintetizados através de uma nova metodologia de síntese, em que cada segmento foi preparado separadamente, e ambos acoplados em uma etapa posterior (produtos SPU). Uma outra série de poliuretanos segmentados similares em compo…
New controlled release water-soluble formulations of sorbic (2,4-hexadienoic) acid were prepared and their inhibitory activity on mycelium growth of Fusarium oxysporum f.sp. radicis-cucumerinum was evaluated. The new products are epoxidized polymers of polyvinylpyrrolidone (PVP) containing covalently bonded sorbic aci…
A mean-field theory is developed for a calculation of the surface free energy of the staggered body-centered solid-on-solid (or six vertex) model as function of the surface orientation and temperature. The model approximately describes surfaces of crystals with nearest neighbor attractions, and next nearest neighbor r…
Structure factors for strontium/chromium- (Sr/Cr) and barium- (Ba) doped potassium titanyl phosphate (KTiOPO(4), KTP) were measured with focused synchrotron X-radiation [0.75000 (9) A] using a fast avalanche photodiode counter. Space group Pna2(1), Z = 8, a = 12.786 (2), b = 6.3927 (8), c = 10.5585 (9) A, T = 293 (1)…
Crystals of compound (I) and (II) are black in reflected light and brown‐ black in transmitted light. The 1H-nmr of the cations of (I), recorded in D6-DMSO, show peaks, relative to the 1H of D6-DMSO, at + 0.46 ppm(rel. int. = 3); + 0.85 ppm(rel. int. = 1.2); + 1.80 ppm (rel. int. = 3); and −4.18 ppm(rel. int. = 1). Th…
Polymer nanocomposites were prepared by mixing ultrahigh-molecular-weight polyethylene and gold colloids coated with a self-assembled monolayer of dode-canethiol. Subsequently, these materials were oriented by solid state drawing which induced the formation of uniaxially oriented arrays of gold particles. As a result…
EPDM sponge rubber profiles for automotive industry are becoming increasingly complex. As there is still little knowledge and process understanding, extensive investigations have been done at the Institute of Plastics Processing to describe the influence of the rheological material properties, the compound components…
Intumescent coatings make the most efficient way of fire retarding of flammable materials. The coatings swell under the influence of heat and form a thick porous charred layer. The latter perfectly insulates a substrate against excessive increase of temperature and oxygen access. In order to make intumescent coatings…
Composites made from a stryrene/unsaturated polyester thermoset matrix and woodflours from different wood species have been prepared and tested. Pine (Pino Eliottis), eucaliptus (Eucaliptus Saligna) and marmelero (Ruprechia Laxiflora), a softwood and two semihard woods respectively, were selected for this study becaus…
The dependence of the absorption coefficient α on photon energy hνwas determined in the spectral range from 1.1 to 3.9 eV at room temperature,for evaporated Gex Te100-x films. The variation of the optical gap Egopt ,dielectric constant ε ,and absorption coefficient,α with composition andannealing are reported. The opt…
The properties of Pb 5 Ge 3 O 11 : Cu 2+ crystals near the temperature of the ferroelectric phase transition are discussed in terms of a phenomenological approach. Assuming a quadratic interaction with the order parameter, the effect of Cu 2+ is considered a result of static distortions, which result from the off-cent…