Materials Literature
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The dark red-purple nickel(IV) periodataes MNilO6(M = Na, K, Rb, Cs or NH4) have been prepared by peroxohexaoxodisulfate oxidation of mixtures of nickel(II) salts, MNO3 and periodate ions in hot aqueous solution. Powder X-ray diffraction studies showed that the structures adopted the space group P312, with hexagonal c…
The complex [{TcN(thiourea)}4(edta)2]·6H2O has been prepared and is shown to consist of a cyclic tetrameric Tc4N4 configuration with four asymmetrical TcN–Tc bridges; each diagonal pair of Tc atoms is bridged by an edta4–ligand and TcN distances range between 1.681(7) and 1.695(7)Å, with N–Tc of 1.977(7) to 2.009(7)Å.
Non-tert-butyl-substituted phenolic porphyrins 5, 7 and 9 undergo aerial oxidation in acidic and basic solutions. Radicals are produced whose singlet EPR spectra differ significantly from those observed for the tert-butyl-substituted phenolic porphyrin 1. In the radical derived from 5a, for example, the unpaired elect…
The structures of Na-containing nasicon-type phases of the form NaxMIIxMIII2 –x(SO4)3 –y(SeO4)y(0 ⩽x⩽ 1.5, 0 ⩽y⩽ 3) at 25 °C have been refined using powder neutron diffraction. The data are consistent with a rhombohedral structure similar to that of Na1 +xZr2SixP3 –xO12, but a reduction in symmetry (R compared to Rc)…
The TIG welding of duplex and super duplex stainless steels is discussed with particular reference to obtaining the optimal phase balance between austenite and ferrite. This is mainly achieved by control of the cooling rate and the weld chemistry. The latter is dependent upon the filler were chosen and the shielding g…
Y2O3-Al2O3-doped β-Si3N4 was sintered at 1700 to 1900°C for 4h in 1 and 10MPa N2 to investigate the effect of amount of the additives on sinterability, strength, fracture toughness and microstructure. Dense materials were obtained by firing the compositions for 6-10mol% additives at 1700°C, 4-6mol% at 1800°C, and 1-4m…
Mechanical and electromechanical properties of monoclinic ZrO2 fiber/PZT composites fabricated by slip casting and ordinary sintering were examined. Bending strength of the composites decreased by increasing the fiber content from 0 to 20vol%. However, the composite containing 5vol% ZrO2 fibers yielded a fracture toug…
Aluminum nitride (AlN) ceramics are commonly used as high thermal conductive ceramics. Their thermal conductivity is strongly dependent on the chemical state of the starting powder surfaces. Control of the powder surfaces is important. For this purpose, the powder surface characteristics must be studied. Conventional…
Changes in the physical properties of pulp during recycling are sometimes reported to be caused by changes in chemical properties offibres. In order to determine the relationship, if any, between physical and chemical properties, a chemical characterization was carried out of several recycled pulps. Measurements of ca…
The results of an experimental study of the 60 Hz ac corona inception voltage at reduced pressures for a cylindrical conductor and a parallel ground plane are presented. Several spacings and bare and insulated conductors of several diameters are considered. Empirical expressions from which a reasonably accurate predic…
We study electronic properties as a function of the six types of local environments found in the octagonal tiling. The density of states has six characteristic forms, although the detailed structure differs from site to site since no two sites are equivalent in a quasiperiodic tiling. We present the site-dependent mag…
The attempt was made to study liposome stability and oxidation under the autoclaving conditions. It was shown that after the preliminary air removal from a liposome sample there was no lipid oxidation (malonaldehyde bis(dimethyl acetate) was used as a control) and liposome content leakage during autoclaving. Liposomes…
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Abstract Molecular self‐assembly is described as a strategy for synthesizing large hydrogen‐bonded supramolecular aggregates that are based on the planar lattice formed of equimolar portions of cyanuric acid and melamine. The aggregates described in this paper contain four to ten individual molecules, are stabilized b…
Molybdenum(VI) has been shown by 183W NMR spectroscopy to replace WVI in the three main types of aqueous polytungstate anion. In ions with the paratungstate-A structure, [W7O24]–6, it can replace any or all of the tungstens, so that at least 19 mixed-metal species can be observed, and mostly also identified. Their rel…
Dynamic viscoelastic properties of phase-separated polypropylene (PP)/styrene-acrylonitrile copolymer (SAN), PP/ethylene-propylene-rubber (EPR) and nylon6 (PA)/SAN blends prepared by melt-blending were measured in molten state. As characteristic to heterogeneous liquids, slow relaxation mechanisms due to domain struct…
We present a dynamic light-scattering experiment on a planarly oriented nematic liquid crystal in the presence of a symmetry-breaking electric field applied normally to the cell planes. This experiment gives direct evidence for the critical behavior of the lowest splay fluctuation mode. A detailed theoretical analysis…
A novel form of LARC™-TPI has been developed which does not exhibit a crystalline melt as was encountered in earlier fonns of this material. Being amorphous allows the powder to be consolidated at temperatures near its glass transition temperature of 260°C (500°F). Adhesively bonded titanium lap shear specimens were f…
We report here the dipole moment (µ) and first hyperpolarizability (β) determined by electric field-induced second harmonic generation, for several merocyanine dyes containing an 1,3,3-trimethylindoline heterocycle as a ‘donor’ in which the ‘acceptor’ end of the molecule and the polyene bridge length was systematicall…
The effect of degassing temperature on the magnitude of the BET specific surface area and other physical properties of magnesium stearate was investigated. Magnesium stearate samples from two manufacturers were degassed using helium at 23°, 30°, 40°, 50° and 60°C. The specific surface area of the degassed samples was…