Materials Literature
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The shielding efficiency of various intrinsically conducting polymers (ICPs) as a function of their intrinsic properties (conductivity and dielectric constant), thickness, and temperature is determined. Two types of shielding, reflection and absorption, by ICPs are discussed. The high shielding efficiencies of highly…
ABSTRACT The most common remedy which is applied to solve mineral scaling problems in water producing North Sea fields is the scale inhibitor "squeeze" process. The central objective of this treatment is to maintain a sufficiently high level (typically, 2-50 ppm) of inhibitor in the produced water to prevent scale for…
Nitrogen-substituted graphite thin films were prepared by chemical vapor deposition (CVD) using pyrrole as a starting material. Ni was used as the substrate material whose temperature was kept in the range 700–1000 °C. The interlayer spacing of these films, determined by x-ray diffraction, was close to that of single-…
Freely suspended smectic-$C$ films, 2, 3, and 4 layers in thickness, of the achiral compound ${\mathrm{C}}_{7}{\mathrm{F}}_{15}{\mathrm{CH}}_{2}\mathrm{O}\ensuremath{-}\ensuremath{\varphi}\ensuremath{-}\mathrm{C}\mathrm{O}\mathrm{O}\ensuremath{-}\ensuremath{\varphi}\ensuremath{-}\mathrm{O}{\mathrm{C}}_{6}{\mathrm{H}}_…
Using high-resolution low-energy electron diffraction we studied in situ low-temperature molecular-beam epitaxial growth of Si/Si(111). At $\ensuremath{\sim}275 \ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ and a deposition rate of $\ensuremath{\sim}7$ bilayers/min, a roughening evolution occurs after an initial tran…
Abstract Liquid crystalline triheptyl cellulose (THC) was synthesized directly from cellulose acetate and heptyl bromide with dimethyl sulfoxide as a single‐component solvent. Synthetic conditions were studied with respect to reaction temperature, time, and yield. The molecular structure and liquid crystalline charact…
The crystal structure and the lattice dynamics of the ordered gamma -ZrD phase were studied by means of neutron diffraction and inelastic neutron scattering (INS). It was found that the actual structure of the gamma phase is orthorhombic, space group Cccm, rather than tetragonal as previously believed. The one-phonon…
Abstract This article deals with the preparation and morphological characterization of porous materials obtained by freezing and lyophilizing silk fibroin solutions. When an aqueous silk solution is frozen at different temperatures (−18, −45, and −80°C), the average pore size decreases with lowering of the freezing te…
We report on neutron scattering observations of the fast picosecond relaxation in two amorphous polycarbonates. Contrary to previous experience, one already observes these fast relaxations far below the glass transition, at temperatures where they cannot be related to the flow process. An explanation in terms of low-b…
Hydrogenated amorphous silicon nitride (a-SiNx:H) films have been fabricated by plasma-enhanced chemical vapor deposition at temperatures ranging from 50 to 250 °C. It is found that as soon as the samples are taken out from the reaction chamber and exposed to the atmosphere, the a-SiNx:H films start to oxide. The oxid…
Sol-gel processes provide techniques to prepare materials which contain silicate and organic groups in a single amorphous phase. Such materials can possibly possess a resultant combination of beneficial physical and chemical properties from silicate glass and organic polymeric materials. Also, silica glasses containin…
Barium gallogermanate glasses are a relatively new family of glasses with tremendous potential for both fiber and bulk optical applications. This ternary system has a broad region of glass forming ability, excellent stability with respect to crystallization, and transmission beyond 5 micrometers . This paper reports t…
The affects of iron on the structure, physical, and optical properties of several iron phosphate and sodium-iron phosphate glasses were investigated using x-ray photoelectron spectroscopy (XPS), Mossbauer spectroscopy, and infrared spectroscopy (IR). Archimedes method, differential scanning colorimeter and Able refrac…
About 200 glasses were made by compressing the hard sphere fluid. The location of the glass transition is not measurably changed when the rate at which the fluid is compressed through the transition is varied by a factor of 500. There is small variance in the properties of the glasses but no statistically significant…
We present 13 C NMR measurements carried out under pressure and between 10 and 300 K on a single crystal of the organic superconductor κ-(ET) 2 Cu[N(CN) 2 ]Br. Under pressure, the large variation of the Knight shift is interpreted as the presence of electronic correlations. We estimate the U/W ratio to be of order uni…
Abstract This book clearly illustrates the limitations of using chemical thermodynamics to describe chemical phenomena in soils--especially with regard to kinetics and molecular mechanisms--and proposes that the quantitative description of soils is not complete without adequate characterization of the rates of the che…
Triglycine sulfate (TGS) is one of the most comprehensively studied ferroelectric materials for infrared detecting devices. The discovery of new materials with more attractive properties together with a growing requirement for uncooled thermal detectors, having better performance than the thermistor bolometers, has re…
Density, DC conductivity and 11B wide-line NMR investigations have been carried out for xFe2O3-(50-x)PbO-50B2O3 glasses (0<or=x<or=20 mol%). The NMR spectra indicated the formation of non-bridging oxygen ions in the borate network upon introducing Fe2O3. The DC conductivity and the activation energy for conduction cha…
New experimental results on Raman scattering from porous silicon and silicon and gallium arsenide nanocrystals are reported. In all of these systems, almost all vibrational modes become Raman active and are remarkably soft. A carrier-induced strain model is proposed to explain the optical properties of these nanocryst…
Abstract The morphology and mechanical properties of polyamide‐based blends prepared in single and corotating twin‐screw extruders were compared using transmission electron microscopy (TEM) techniques. Reactive polyamide blends with SEBS‐ g ‐MA (a maleated styrenic triblock copolymer with ethylene–butvlene midblocks),…