Materials Literature
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The elastic constants C11, C33, C44, C13 of oriented poly propylene films are measured with Brillouin scattering and are compared with the elastic constants obtained from extruded poly propylene rods. The photoelastic constants p12, p13, and p31 of the extruded rod samples are measured by comparison to a poly(methylme…
Abstract Undrawn and drawn polyamide‐6 bristles were annealed in vacuum at different temperatures between 80 and 228°C. It was found that at higher temperatures (above 140 to 160 °C) besides an increase of the crystallinity an additional solid state postcondensation proceeds, leading to a narrower molecular weight dis…
Abstract Measurements on the linear thermal expansivities α∥ and α⊥ parallel and perpendicular to the extrusion direction, respectively, have been carried out between −160 and 30°C for atactic polystyrene (aPS) with extrusion ratio 1 ≤λ≤ 15 and isotactic polystyrene (iPS) with 1 ≤λ≤ 7.5. For both aPS and iPS, α∥ decre…
The response of seed germination to substrate water potential was determined for several plant species of the arctic tundra. Seeds were collected from Cape Thompson and Eagle Summit, Alaska and germinated on dialysis membranes over water solutions of polyethylene glycol with osmotic potentials of 0 to −6 bars. Germina…
The tubular accessory gland consists of a simple secretory epithelium surrounded by a muscular coat. Over the pupal instar, the gland increases ten-fold in volume and 15-fold in length. Pupal development is divisible into a phase of mitosis and one of cell growth. During the mitotic phase, cytoplasmic membranes are sp…
We formulate a theory of a charge-density-wave (CDW) distorted superconductor, in the presence of impurities and CDW fluctuations. This theory is expected to be applicable to the layered compound $2H$-Nb${\mathrm{Se}}_{2}$. Our primary aim is to compute the superconducting density of states ${N}_{s}(\ensuremath{\omega…
films were examined by transmission electron microscopy using defocus contrast. Phase contrast effects have been observed in both amorphous and crystalline anodic films. These contrast effects have been interpreted as arising from discrete voids, 2–4 nm in diameter, present at apparent densities in the range . Strings…
Abstract A polymer with high aromaticity and/or cyclic ring structures chain backbone usually has high heat, thermal, and flame resistance. Two diglycidyl ethers of bisphenols were prepared from 4,4′ isopropylidenediphenol (DGEBA) and 9,9‐bis(4‐hydroxyphenyl) fluorene (DGEBF) for evaluation. Four boroxines—trimethoxyb…
The electrical conductivity of partially stabilized zirconia was investigated as a function of frequency (2 Hz to 100 kHz) and temperature (400° to 1000°C) by measuring ac admittance on a 2‐probe cell using Lissajous figures. The dependence of the conductivity on annealing time was investigated with in situ conductivi…
Abstract Critical review shows that probability estimates regarding human scalp and pubic hair individualization are in error owing to defects in experimental design. The inherent bias is evaluated to preclude improper use of these probability estimates in the future.
Abstract The luminescence of LiLa 1− x M x P 4 O 12 (M = Ce 3+ , Eu 3+ , Tb 3+ , Bi 3+ ) is measured. Only for the Ce 3+ ion pronounced concentration quenching is observed. The spectra of pairs of activators differ slightly from those of isolated activators. The Bi 3+ emission is strongly Stokes shifted and is ascribe…
Ion conduction is considered through electrolytes containing an immobile gradient in the electronic/ionic transport number ratio. It is shown that internal deposition of the metal phase (reduced ions) can occur in such electrolytes during electrolysis. A "critical" applied voltage or current density can be formulated…
The occurrence of glass in the three binary and one ternary oxide systems containing Ge, Bi, and Tl was studied by air‐ and water‐quenching melted samples. Bulk glass occurred widely in these systems and was obtained with as little as 10 mol% GeO 2 , combined with 68 mol% BiO 1.5 and 22 mol% TIO 0.5 . Some glass occur…
The applicability of the hydrodynamical model, obtained from the high-frequency expansion of the density-density response function, for calculating the surface plasmon dispersion relation and plasmons of higher polarity is analyzed. Of crucial importance to get any result for the dispersion coefficients is that the un…
At high conversions of monomer (or high polymer concentrations), chain entanglements and a glassy-state transition (significant reduction in free volume) can have a profound effect on the relative rates of free-radical reactions which control the molecular structure of polymer chains. In particular, it will be shown t…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHigh-pressure synthesis, crystal structures, and luminescence properties of europium(II) metasilicate and europium(II)-activated calcium and strontium metasilicatesKenichi Machida, Ginya Adachi, Jiro Shiokawa, Masahiko Shimada, Mitsue Koizumi, Kaichi Suito, and Akifumi Onode…
The classical form of the Nernst-Einstein relation is discussed. It is shown that it leads to an obviously non-general relation between the tracer diffusion coefficient and the chemical diffusion coefficient. The Onsager phenomenological equations are used to deduce an exact form of the Nernst-Einstein relation which…
Abstract The swelling behavior of water in a poly(ethylene–vinyl alcohol) copolymer (70 mol % vinyl alcohol) has been characterized at 25°C by vapor and liquid sorption experiments over a range of water activities. The activity of the vapor phase has been varied by incrementing the pressure of the water vapor in the s…
Abstract The grafting of styrene and acrylamide, from both their binary and unitary systems, on cellulose acetate film was studied by means of the cobalt‐60 postirradiation grafting technique. The extent of grafting was found to be dependent on preirradiation dose, reaction time, and temperature, and the optimum condi…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAn intermediate-spin iron(III) porphyrin complex with a vinylidene group inserted into a iron-nitrogen bond: paramagnetic susceptibility, EPR, and Moessbauer propertiesDaniel Mansuy, Irene Morgenstern-Badarau, Marc Lange, and Pierre GansCite this: Inorg. Chem. 1982, 21, 4, 1…