Materials Literature
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The relevance of powder packing structure and microstructure in alumina ceramics made through the injection molding process was investigated in the present study. The packing structure of oriented powder particles was retained in the present ceramics after sintering. Even after significant growth, the orientation of t…
This research investigates the infrared absorption intensity and isotope-dependent frequency shifts of CH stretching on diamond C(111) single-crystal surfaces by Fourier transform infrared spectroscopy (IRS). By employing single-pass direct absorption and in situ surface oxidation methods, a single sharp feature at νm…
Ultraviolet probe ion and far-infrared spectroscopic results for barium borate glasses indicate the existence of two types of cation-hosting site differing in electron density, that is, basicity. The pattern is similar to the sodium borate glass system, which has the same average theoretical optical basicity trend. Ho…
The established pathway for the last two steps in purine biosynthesis, the conversion of 5-aminoimidazole-4-carboxamide ribonucleotide (ZMP) to IMP, is known to utilize 10-formyl-tetrahydrofolate as the required C1 donor cofactor. The biosynthetic conversion of ZMP to IMP in three members of the domain Archaea, Methan…
This paper describes the properties of some new organic–inorganic photochromic layers. They are based on a hybrid organic–inorganic matrix in which tungsten heteropolyoxometallates (SiW12O4−40, PW12O3−40) are entrapped in a network obtained from the reaction of 3-glycidoxy-propyltrimethoxysilane. The high homogeneity…
Abstract A comparison was made of the room temperature strain-crystallization of naturally-occurring cis -1,4-polyisoprenes having varying non-rubber content. A variety of measurements were employed to assess crystallization, including stress relaxation, optical birefringence, and the infrared absorption spectrum. All…
Among the developments associated with sol-gel materials, of relevance is the entrapment of photochromic molecules. Photochromic-doped sol-gel gel-glasses can be prepared by adding a spiropyrane photochromic dye to a solution of ethoxy silane monomers containing non-reacting ethyl radicals. After polymerization, norma…
Liquid-liquid dispersions with drop sizes less than 100 μm cannot be separated using gravity settlers, but need more effective separation tools. In this situation fibre beds represent a relatively simple and low-cost form of pre-separation equipment to enlarge the droplets by drop coalescence as a first step in gravit…
Dielectric properties of quantum paraelectric materials, SrTiO3, CaTiO3 and (La1/2Na1/2)TiO3, were presented and discussed since they show the titled dielectric properties in the lowest temperature range. In order to show our strategy to obtain the titled materials for microwave resonator applications, dielectric prop…
The sorption of Thermomonospora fusca E3 and E5 and Trichoderma reesei CBHI cellulases on bacterial microcrystalline cellulose (BMCC) was investigated to measure binding reversibility and surface exchange. The adsorption and desorption curves for CBHI were comparable; this suggests a totally reversible binding process…
The crystal structure of YCoO3has been determined from Rietveld analysis of the powder neutron diffraction data at 17, 100, and 300 K. At each temperature, the structure is a distorted perovskite with orthorhombic symmetry, space groupPbnm(Z=4). The lattice parameters, at 300 K, are 5.1388(5)× 5.4191(5)×7.3658(7) Å. S…
The misorientation angle is the simplest characteristic of the difference between orientations of two crystallites in a polycrystalline material. Another is the corresponding rotation axis. These quantities can also be determined when crystallites are of different types and possibly different symmetries, as in multiph…
The effect of pH on the Langmuir monolayer behavior was investigated for the poly( o -anisidine) (POAS) conducting polymer. The Langmuir−Schaefer (LS) films were prepared at pH 1 of the subphase, where the doping during the monolayer formation was essential for the high quality of the conducting polymer film. The LS f…
The X-ray crystal structure of a uridine vanadate-ribonuclease A complex has been determined at 1.3 A resolution. The resulting structure includes all 124 amino-acid residues, a uridine vanadate, 131 water molecules, and a single bound 2-methyl-2-propanol. Side chains of 11 surface residues showing discrete disorder w…
Films of Ti dioxide, mixed Ti–Ce oxide, and Ce dioxide were produced by reactive dc magnetron sputtering. Electrochemical lithiation was probed by chronopotentiometry, cyclic voltammetry together with optical transmittance recording, and impedance spectroscopy. Evidence was found for inserted electrons being accommoda…
Using ab initio methods, the position and the orientation of a CO 3 2- impurity in a hydroxyapatite lattice is studied. The CO 3 2- ion is oriented in a plane that makes an angle of 7° with the crystallographic c axis. The carbon atom and two oxygen atoms occupy positions close to the axis, whereas the third oxygen is…
The geometries and second-order nonlinear optical properties of the four conformers of donor−acceptor-substituted calix[4]arene molecules are investigated by means of semiempirical quantum-chemical techniques. The evolution of the second-order polarizability β is analyzed with respect to changes in conformation and th…
Diethylaminoethyl–chitin (DEAE–chitin) was synthesized by introducing DEAE groups onto the C(6)–OH in chitin. DEAE–chitin was N-deacetylated by heating in aqueous 10% sodium hydroxide containing sodium borohydride to prepare the diethylaminoethyl–chitosan (DEAE–chitosan). In addition, DEAE–chitin was quaternized with…
We report the Ni ${\mathrm{L}}_{2,3}$-edge magnetic circular dichroism (MCD) measurements of ferrimagnetic ${\mathrm{Zn}}_{\mathrm{x}}$${\mathrm{Ni}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Fe}}_{2}$${\mathrm{O}}_{4}$ (x=0.0, 0.26, 0.50, and 0.75). The Ni MCD asymmetry ratio was found to decrease with increasin…
We have investigated the order-disorder phase transition in Cu-Al-Be alloys close to the eutectic composition. X-ray diffraction measurements have been performed to characterize the ordered structure and to follow the evolution of the degree of long-range order with temperature. Results show that the transition is fir…