Materials Literature
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We propose a model, translated into an algorithm, to simulate nonisothermal sintering of polydispersed glass undergoing concurrent crystallisation. The model is based on the two classical sintering stages proposed by Frenkel and Mackenzie–Shuttleworth. The input parameters are green density, particle size distribution…
Among porous ceramic with unidirectionally aligned pores, synthesized from a water-based slurry using unidirectional freezing and freeze-drying process, porous silicon nitride showed a characteristic microstructure wherein the macroscopically aligned open pores contained many fibrous grains protruding from their inter…
Combinations of different yarn components are useful for improving yarn structure and properties. In this research, we describe a new method of combining filament yarns and staple fibers on a modified open-end rotor spinning frame. By changing filament over-feed, we have produced three kinds of hybrid yarns while keep…
A waveguide can be self-written by a beam of light propagating in a photosensitive material. We report the first observation of self-writing effects in bulk chalcogenide glass and investigate the influences of different writing beam sizes and powers. We observe increases in refractive index of 2.5/spl times/10/sup -4/…
Optical diffraction has been demonstrated to be a useful method with which to noninvasively examine materials and structures that result from lithographic processes used in the semiconductor indus- try to create integrated circuits. The process of inferring the geometry of the lithographically created structures from…
A surface-structure study of human tooth enamel crystals has been carried out by high-resolution electron microscopy (HREM). The surfaces of several crystals have been examined and the surfaces of a single crystal are described here. The observations made on this crystal are similar to the observations made on the oth…
A first-principles-derived approach is used to study structural, piezoelectric and dielectric properties of Pb(Zr 1 m x Ti x )O 3 (PZT) solid solutions near the morphotropic phase boundary at low temperature. Three ferroelectric phases are found to exist: a tetragonal phase for larger x compositions, a rhombohedral ph…
The dynamic rheological behaviour of gamma-irradiated 12.8 wt% poly(vinyl alcohol) (PVA), 12.8 wt% poly(vinyl pyrrolidone) (PVP), and a blend of 8 wt% PVA and 4.8 wt% PVP aqueous solutions have been studied pre- and post-gelation. The non-irradiated solutions displayed rheological behaviour typical of dilute to semi-d…
A decoction of leaves and stems of Anisomeles indica (Lamiaceae) is claimed to possess anti-inflammatory activity in Sri Lankan traditional medicine. The plants at both preflowering and flowering stages are used as an anti-inflammatory agent. However, the anti-inflammatory activity of the plant has not been scientific…
Optical scatterometry by use of a neural network is now recognized as an efficient method for retrieving dimensions of gratings in semiconductors or glasses. For an on-line control, a small number of measurements and a rapid data treatment are needed. We demonstrate that these requirements can be met by combining data…
PET fabric/polypyrrole composites with high electrical conductivity were prepared by polymerization of polypyrrole on a PET fabric through both chemical and electrochemical oxidation of pyrrole monomer. We investigated environmental stability of the composite and measured activation energy using the Arrhenius Equation.
The influence of trace amounts of transition metals (Cr, Mn, Fe, Co) on the structural and catalytic properties of silica and 1 wt% titania–silica nanoparticles prepared by flame synthesis has been investigated. The transition metal concentration was varied from 40 to about 2000 ppm by admixing the corresponding trans…
The study on thermal energy transport system by synthesis and decomposition reactions of methanol was reviewed. To promote energy conservation and global environment protection, a two-step liquid-phase methanol synthesis process, which starts with carbonylation of methanol to methyl formate, then followed by the hydro…
In this paper, we develop a fully automatic mesh filtering method that adaptively smoothes a noisy mesh and preserves sharp features and features consisting of only few triangle strips. In addition, it outperforms other conventional smoothing methods in terms of accuracy.
We have used thermogravimetry and X-ray absorption spectroscopy to examine the water content, oxidation state, and local structure of V for V 2 O 5 ⋅ n H 2 O aerogels and ambigels in the pristine state and after heating under vacuum (100 μTorr) at 114 and 220°C for 25 h. On the basis of thermogravimetric analysis, the…
Reactions of salicylaldehyde (1) with β-nitrostyrenes (2), ( 4), and (6) in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) without the use of solvent at 40 ℃ gave high yields of the corresponding 3-nitrochromenes, respectively.Other conjugated nitroalkenes were also used to react with salicylaldehyde under the…
AlCl 3 crystallizes as an ionic solid but melts to form a molecular liquid consisting of Al 2 Cl 6 units. In order to see if this transition involves a major change in electronic structure, the dimer and crystal of AlCl 3 are examined with the aid of generalized gradient corrected density functional theory (GGC-DFT) c…
A new hydride in the MgH2–YH3 system was found by using a high pressure of 5 GPa, and their crystal structure, thermal stability and hydrogen content were studied. The high-pressure synthesis was carried out at 1073 K for 2 h under 5 GPa by using an anvil-type apparatus. In the MgH2–xat%YH3 system (x=33–100), novel hy…
Expressions are presented for the analytical energy derivatives of the ligand field stabilisation energy (LFSE) within the angular overlap model formalism. In addition to the σ-bonding contributions already incorporated in the ligand field molecular mechanics (LFMM) code, explicit contributions from π-bonding and d–s…
The use of SiC/SiC composites for nuclear application has recently been considered because of intrinsic low activation and superior high temperature mechanical properties of SiC. The property of SiC fiber is a key issue in order to improve mechanical properties of SiC/SiC composites following irradiation. SiC/SiC comp…