Materials Literature
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The performance of different membrane reactors for the epoxidation of ethylene was compared with that of a conventional fixed-bed reactor (FBR), under identical overall reaction conditions, using a cesium-doped silver catalyst supported on α-alumina. Two packed-bed membrane reactor configurations were used, one using…
The electronically excited states of the phthalimide chromophore have been studied by means of linear dichroism (LD) of samples partially oriented in poly(vinyl alcohol) films, magnetic circular dichroism (MCD), and circular dichroism (CD) spectroscopy. On the basis of the LD measurements, the low-energy tail (340−320…
We present effects of pressure and temperature on $4f\ensuremath{-}4f$ luminescence properties of ${\mathrm{Sm}}^{2+}$ ions in $M\mathrm{FCl}$ crystals $(M=\mathrm{Ba},$ Sr, and Ca). Temperature experiments indicated that a two-step nonradiative process ${(}^{5}{D}_{J}\ensuremath{\rightarrow}{4f}^{5}5d$ thermal crosso…
Electroactive and photoactive copolymers derived from fluorenes have been prepared from palladium-catalyzed Suzuki couplings. For instance, poly((4,4prime-biphenylene)-2,7-(9,9-dioctylfluorene)) and poly((2,5-thienylene)-2,7-(9,9-dioctylfluorene)) exhibit strong emission in the blue region (406 nm, phi fl = 0.72) and…
Epitaxial Cu films were grown on H-terminated Si(100), Si(110) and Si(111) substrates by magnetron sputtering. The epitaxial orientation relationships and microstructural characteristics of the Cu films were studied by x-ray diffraction (XRD) including the conventional θ-2θ mode, rocking curve and pole figures, as wel…
The thermal decomposition and runaway reaction of cumene hydroperoxide (CHP) in cumene were studied by thermal analysis and by using the VSP-II adiabatic calorimeter. Decomposition kinetics were determined in various CHP concentrations in cumene. The reaction order of 20wt%, 35wt%, 50wt%, 65wt%, and 80wt% was determin…
Magnetization as a function of field and temperature for a ferromagnetic Heusler alloy ${\mathrm{Ni}}_{2}\mathrm{MnGa}$ is reported. Magnetization above the Martensitic transition displays a field-dependent peak effect, a direct magnetic evidence of premartensitic phase. At low fields, the peak effect occurs at a temp…
Wet spinning of fibers from a solution of polyaniline doped with 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA) is reported. The fibers spun into selected coagulation solvents are inherently electrically conductive and can be cold drawn to extensions of >500%with a concomitant rise in electrical conductivity of…
Changes in the mechanical and thermal properties, as well as in the microstructure, of unburned MgO‐C bricks containing Al and Si powders were investigated at selected temperatures. Specimens with heat treatments at 500°C shrank and exhibited higher apparent porosity than untreated specimens. The bending strength and…
The structures of ion conducting mixed alkali metaphosphate glasses $({\mathrm{Li}}_{2}\mathrm{O}{)}_{x}\ensuremath{-}({\mathrm{Rb}}_{2}\mathrm{O}{)}_{1\ensuremath{-}x}\ensuremath{-}2{\mathrm{P}}_{2}{\mathrm{O}}_{5}$ have been examined by neutron diffraction and Raman spectroscopy. The results show that the short-rang…
The precise conversion of CT numbers to their electron densities is essential in treatment planning for hadron therapy. Although some conversion methods have already been proposed, it is hard to check the conversion accuracy during practical therapy. We have estimated the CT numbers of real tissues by a calculational…
To evaluate the safety factor for flight feather shafts, in vivo strains were recorded during free flight from the dorsal surface of a variety of flight feathers of captive pigeons (Columba livia) using metal foil strain gauges. Strains recorded while the birds flew at a slow speed (approximately 5-6 m s-1) were used…
Abstract Morphology, rheology, and permeability studies were carried out for blends of polyethylene (PE) and polybutylene terephthalate (PBT). The effect of draw ratio at the die exit of the extruder on blend morphology was investigated, and thus isotropic fibrillar morphology with different aspect ratio was obtained.…
A multilayered super-resolution near-field structure (Super-RENS) disk with the order of SiN/Sb/SiN/GeSbTe/SiN was produced on a polycarbonate substrate. The readout resolution properties of small phase change marks recorded through an antimony thin film were investigated. The linear and radial densities have been car…
A gradient bending theory is developed based on a strain energy fonction that includes the classical Bernoulli-Euler term, the shape correction term (microstructural length scale) introduced by Timoshenko, and a term associated with surface energy (micromaterial length scale) accounting for the bending moment gradient…
Thin films of hafnium oxide have been prepared by using a dual ion beam sputtering system. A study of their physical properties is reported. In particular, structural and compositional characterization was performed by means of x-ray diffraction and x-ray photoelectron spectroscopy techniques, showing a mixture of amo…
Clay mineral assemblages of a soil chrono-association comprising five fluvial surface members (QGH1 to QGH5) of the Indo-Gangetic Plains between the Ramganga and Rapti rivers, north-central India, demonstrate that pedogenic interstratified smectite–kaolin (Sm/K) can be considered as a potential indicator for paleoclim…
New photochromic carotenoid-like chromophores containing the dithienylperfluorocyclopentene fragment have been synthesized and characterized by UV/Vis spectroscopy. The quantum yields of the photochromic forward and back reactions of these compounds have been determined and are found to decrease sharply with increasin…
In the Adamello-Brenta Regional Park (Trentino, Italy), the diatom communities of 30 mountain springs, 15 on crystalline and 15 on carbonate substratum, were studied between 1993 and 1996. Two of them, one from each substratum type, were sampled monthly for a more detailed investigation of seasonal changes in communit…
Hydrogen bond strength depends on both temperature and pressure. The gradient for hydrogen bond strength with temperature, or pressure, depends upon the hydrogen bonded structure. These features create an intimate connection between quantum mechanics and thermodynamics in the structure of liquid water. The equilibrium…