Synthesis of Monosubstituted [1.1.1]Propellanes
The synthesis (up to the 10‐g scale) and purification of alkyl‐ and methoxyalkyl‐substituted [1.1.1]propellanes are described.
Materials Literature
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Determination of iron core losses under influence of third-harmonic flux component
The core loss for a magnetic material under excitation can be estimated from the flux density versus the field-strength loops or B-H loops. A method is presented for predicting the position, size, and number of minor loops formed in the B-H loop, while harmonics of known magnitude and phase angle occur along with the…
Plasma deposition and etching of diamond‐like carbon films
Abstract Diamond‐like carbon films have been deposited from ternary mixtures of butadiene, hydrogen and argon in a parallel plate plasma reactor at constant pressure and power. These films have been etched in O 2 and CF 4 /O 2 plasma discharges. A new linear relationship between the composition of the deposition gas m…
Carbon-Black-Elastomer Interaction
Abstract A number of different techniques were applied to measure carbon-black-surface reactivity and the level of black-polymer interaction in four different elastomer systems (SBR, IIR, NR, and NBR) representing differences in unsaturation, crystallinity and polarity. Known within-grade surface activity variations w…
Polymer blends and polymer solutions: a Born-Green-Yvon integral equation treatment
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolymer blends and polymer solutions: a Born-Green-Yvon integral equation treatmentJ. E. G. LipsonCite this: Macromolecules 1991, 24, 6, 1334–1340Publication Date (Print):March 1, 1991Publication History Published online1 May 2002Published inissue 1 March 1991https://pubs.ac…
Characteristic matrix method for stratified anisotropic media: optical properties of special configurations
Berreman’s 4 × 4 matrix method is used to study the optical properties of special configurations. Under certain conditions the expression for the characteristic matrix of a homogeneous anisotropic slab can be greatly simplified. If these conditions are also fulfilled for each slab of a multilayered system, relations b…
Evolution of thermochromism during oxidation of evaporated vanadium films
Thin vanadium oxide films were made by vacuum evaporation followed by the annealing posttreatment in the presence of air. The thickness increased by a factor as large as approximately 2.3 on oxidation. Electron diffractograms indicated a bcc ? monoclinic transformation during the annealing, and electron micrographs sh…
Memory-dependent nonlocal electromagnetic elastic solids and superconductivity
Constitutive equations are developed for nonlinear (and linear) nonlocal electromagnetic elastic solids that possess continuous memory of past fields. The consequence of the second law of thermodynamics is studied. Phenomenological laws are given for special cases of nonlinear optics, nonlinear magnetism, conduction,…
Polyvinylidene Fluoride (PVDF) Appearance, General Properties and Processing
SOLEF1 polyvinylidene fluoride (PVDF or PVF2). characterized by a high crystallinity, possesses certain basic properties shared by all the varieties of PVDF: chemical inertness, thermal stability, good electrical porperties UV and γ radiation stability and non-toxicity.It is distinguished by excellent resistance to he…
Diffusionless Cubic‐to‐Tetragonal Phase Transition and Microstructural Evolution in Sintered Zirconia–Yttria Ceramics
Microstructural changes associated with the diffusionless cubic‐to‐tetragonal phase transition ( c–t ′) in sintered ZrO 2 –Y 2 O 3 ceramics with 4 to 20 mol% Y 2 O 3 are investigated. Ceramics containing 4 to 7 mol% Y 2 O 3 that are quickly cooled from high temperatures experience cubic‐to‐tetragonal transformation by…
Temperature Dependence of Hardness in Yttria‐Stabilized Zirconia Single Crystals
The temperature dependence of hardness and microcracking in single‐crystal 9.5‐mol%‐Y 2 O 3 ‐fully‐stabilized cubic‐ZrO 2 was studied as a function of orientation. Crack lengths increased with increased temperature up to 500°C; above 800°C, no cracks were found, indicating an indentation brittle‐to‐ductile transition…
Lipoxygenase as Blanching Index for Frozen Vegetable Soybeans
ABSTRACT Blanched samples of frozen vegetable soybeans using peroxidase (POD) and lipoxygenase (LIP) as blanching indices were compared with unblanched samples during storage by sensory evaluation, vitamin C determination and remaining enzyme activity. Samples using LIP and POD as blanching indices showed no significa…
Electronic excitations, luminescence and lattice defect formation in α-al2O3crystals
We review studies of the effects of electronic excitation in α-Al2O3 crystals, paying special attention to the problem of the existence of self-trapped excitons and self-trapped holes in the material. After a brief review on the crystallographic and electronic structures, information on thermal and radiation-induced d…
Heat capacity and other thermodynamic properties of linear macromolecules X. Update of the ATHAS 1980 Data Bank
The prior published ATHAS 1980 Data Bank of experimental heat capacities of linear macromolecules that included critically reviewed material on almost 100 polymers is updated. In addition, the data bank has been computerized so that future updates can be made continuously, and new print-outs or computer files will be…
Molecular Motions and Phase Transitions in Solid CH3NH3PbX3 (X = C1, Br, I) as Studied by NMR and NQR
Abstract The temperature dependence of 35 C1, 81 Br, and 127 I NQR frequencies and 1 Hspin-lattice relaxation times (T 1 ) for CH 3 NH 3 PbX 3 (X = Cl, Br, I) was measured through the successive phase transitions in these solids. The isotropic reorientation of the CH 3 NH 3 ions takes place in the higher-temperature p…
Preparation of porous materials by chemical activation of the Llano vermiculite
Abstract A mild acid attack of the Llano vermiculite produces porous materials suitable for use as cracking catalysts and/or catalysts supports. After HCl attack at 80°C (1 m ), the number of acid sites measured by the Hammett indicator method is ∼0·50/nm 2 , and the specific surfaces are 245 m 2 /g after calcination…
Effect of Green Density on Densification and Creep During Sintering
The effect of green density on both the densification rate and the creep rate was measured simultaneously during sintering by loading dilatometry. The experiments were performed on zinc oxide powder compacts with five different green densities covering a range of 0.39 to 0.73 of theoretical. The samples were heated at…
Extractive crystallization of salts from concentrated aqueous solution
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTExtractive crystallization of salts from concentrated aqueous solutionDavid A. Weingaertner, Scott Lynn, and Donald N. HansonCite this: Ind. Eng. Chem. Res. 1991, 30, 3, 490–501Publication Date (Print):March 1, 1991Publication History Published online1 May 2002Published inis…
Stability, Electronic Structure, and Phase Diagrams of Novel Inter- Semiconductor Compounds
High-technology electronic devices are based on highly specialized core materials that make their operation pos sible : semiconductors. Unfortunately, the range of mate rial properties that make high-technology devices work is extremely narrow, since the sheer number of useful semiconductors is small. Hence, a major c…
Effects of surface roughness on adsorbed polymers
Polymer chains adsorbed on rough impenetrable surfaces have been investigated analytically and by simulations. The cases of physical and chemical roughness of surfaces are identified and their distinctive effects on the adsorption characteristics are studied. For the chemically rough surface the adsorption temperature…