Superconductivity in Polysulfur Nitride(SN)X
The inorganic crystalline polymer polysulfur nitride has been found to become superconducting with a transition temperature of (0.26\ifmmode\pm\else\textpm\fi{}0.03)\ifmmode^\circ\else\textdegree\fi{}K.
Materials Literature
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Metal-Insulator Transition in(V1−xCrx)2O3
Resistivity measurements on crystals of ${({\mathrm{V}}_{0.99}{\mathrm{Cr}}_{0.01})}_{2}$${\mathrm{O}}_{3}$ grown by vapor transport confirm our earlier results. They do not support the reinterpretation of metal-insulator transition given by Honig, Chandrashekhar, and Sinha in a recent Letter.
An Experimentally Verified NOx Emission Model for Gas Turbine Combustors
An analytical model has been developed to simulate the thermal NOx emission processes in various gas turbine combustors for a variety of fuels. The NOx emissions predicted by the model are in excellent agreement with available laboratory and field data. Its capability to simulate the water injection process accurately…
PHASE TRANSITIONS OBSERVED ON WARMING FAST-QUENCHED MBBA
When the nematic phase of MBBA is rapidly cooled by exposure to liquid nitrogen a glassy solid is formed which, X-ray diffraction studies indicate, has the nematic ordering quenchedin. The sequence of events which occur upon reheating this glass was monitored using X-ray diffraction and a differential thermal techniqu…
A New Method for Determining Maturity of Cotton Fibers
The alkali centrifuge technique has been extensively studied in relation to maturity, and the results have shown that it is a simple, fast, and highly reproducible test method for determining the maturity of cotton fibers either in the raw state or after soxhelet extraction to remove waxes, provided there is no damage…
Influence of Fiber Properties on Wrinkling Behavior of Fabrics
The recovery of fabrics from bending strains is basically the property which determines whether the fabric will be wrinkle-free and is thus an important factor in the total concept of ease-of-care. The capacity of a fabric to recover from a bending strain depends on a number of physical properties of the single filame…
A New, Low-Temperature Synthesis of Plutonium and Uranium Nitrides
Plutonium and uranium nitrides have been synthesized by reacting a solution of the actinide iodide and a solution of sodium, potassium, or calcium in anhydrous liquid ammonia. The precipitate was identified by elemental analysis, infrared absorption, and x-ray diffraction. Nitrides are of interest as fast breeder reac…
Properties of 713LC Compacts, Hot Isostatically Pressed at Supersolidus Temperatures
Abstract Nickel-base superalloy (713LC) powders produced by two techniques have been consolidated by a single-stage, hot isostatic pressing operation to obtain fully dense, coarse-grained (ASTM 1-2) material. After heat treatment the compacts produced by powder from the rotating electrode process gave tensile strength…
ALIGNMENT INVERSION WALLS IN NEMATIC LIQUID CRYSTAL LAYERS DEFORMED BY AN ELECTRIC FIELD
Alignment inversion walls in nematic liquid crystal layers deformed by an electric field have been observed. Different types of walls in layers with planar boundary conditions could be distinguished. Beginning at some irregularity, the walls split into pairs of disclination lines. The speed of the splitting depends li…
Effect of Nearest Neighbor Ions on the Hyperfine Fields at 57Fe Nuclei in TbFe1-xCrxO3
Mössbauer experiment has been performed in TbFe 1- x Cr x O 3 . Hyperfine field at 57 Fe nuclei is 550 kOe at 0 K for x =0, and it decreases by 9 kOe when one Fe 3+ ion is replaced by a Cr 3+ ion at the nearest neighbor site of 57 Fe 3+ ion. This decrease is attributed to the change in the supertransferred hyperfine i…
Wroewolfeite, a new copper sulphate hydroxide hydrate
Summary Wroewolfeite is a new mineral from the Loudville lead mine in Loudville, Massachusetts, U.S.A. The mineral occurs as blue, monoclinic crystals, twinned on {001}, very similar in appearance to posnjakite and langite. It is formed as small isolated pinacoidal crystals (up to 1.0 mm) implanted on covelline and ch…
Acoustic reflection and transmission characteristics for thin plates
A method for determining the acoustic properties of thin plates is described. Existing theoretical expressions are used to calculate transmission and reflection coefficients for sound waves striking the plates at arbitrary angles of incidence. Theory is substantiated by experimental data, and refined values for absorp…
The Influence of Fine Structure on the Flame Retardance of Cellulose
The relative efficiencies of phosphorus and sulfur-based flame-retardant systems have been compared on cotton, ramie, and rayon. Sulfur-based systems were found to be equally effective on all the substrates tested. Phosphorus-based flame retardants were significantly less effective on rayon than on cotton or ramie. Th…
NOVEL SMECTIC POLYMORPHIC BEHAVIOUR IN HOMOLOGOUS SERIES OF MESOGENS
The high alternation of nematic thermal stabilities found in the series of ω-phenylalkyl 4-(4'-phenylbenzylideneamino) cinnamates as the homologous series was ascended has been further exaggerated by substituting the terminal phenyl ester ring with methyl or chloro substituents in the 3"- or 4"-positions. Nematic phas…
CALORIMETRY OF LIQUID CRYSTAL PHASE TRANSITIONS
HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci-entific research documents, whether they are pub-lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire H…
Nitrogen Diffusion in Zirconium Nitride
Diffusion of nitrogen in plates obtained by direct nitridation of 99.995 weight per cent zirconium sheets at 1150°C was studied using the 15 N gas‐solid exchange technique. These specimens were characterized by chemical analyses, density, lattice parameter, and structural measurements. The diffusion anneals were perfo…
Raman‐active phonons in α‐boron
Abstract Single crystals of the α‐rhombohedral boron modification, prepared by chemical vapor deposition, were investigated by Raman scattering. Twelve quite strong peaks were observed in the Raman spectrum. The results are compared with group theoretical predictions and a lattice dynamical model, recently developed f…
SELF-DIFFUSION IN NEMATIC LIQUID CRYSTALS
Using a properly parameterized functional form of the momentum autocorrelation function, we have calculated, in a closed analytical form, the average diffusion coefficient D of nematic liquid crystals in terms of the molecular parameters such as intermolecular distances, coupling strength and molecular dimensions. Usi…
ESR Study of MoO3 Obtained from Thermal Decomposition of Ammonium Molybdate
Abstract The thermal decomposition of ammonium molybdate, between 100–600°C was studied by ESR technique. At 250 °C all ammonium molybdate was decomposed into molybdenum trioxide. Samples taken at 250, 300, 350, 400 and 450 °C all gave ESR signals. Samples at other temperatures (higher and below of this temperature ra…
Thermoanalytical Methods in Vulcanizate Analysis I. Differential Scanning Calorimetry and the Heat of Vulcanization
Abstract Our objective has been to demonstrate that DSC is a convenient and rapid technique for the study of elastomer vulcanization characteristics. Although we have been concerned only with NR and NR-BR blends, the observation of exothermicity in sulfur vulcanization is quite general. Similar observations on sulfur…