Materials Literature
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A new method is described for determining the composition of a mixture of disulfides, trisulfides, and tetrasulfides by cyclic voltammetry. Oxidation potentials of the three species are generally well separated and become more positive when the sulfur chain increases in length. Results are compared with those obtained…
Polyurethane acrylate oligomers (PUA) were prepared by a competitive reaction of 4,4′-dicyclohexyl methane diisocyanate (H12MDI) with hydroxy terminated polybutadiene (HTPB) and hydroxyethylacrylate (HEA). Kinetic models were established for noncatalytic and catalytic systems, and the reaction constants were calculate…
The Inorganic Crystal Structure Database containing a total of 209 entries for 128 different materials reported in point group 4 mm , of which eight are for previously known ferroelectrics. Analysis of the remaining entries, assuming the structure determinations reported are correct, leads to the prediction of an addi…
Linseed oil is used in the dual roles of the plasticizer and the fatty acid component of the activator in nitrile rubber vulcanizates. The study shows that the substitution can substantially improve the mechanical properties in addition to other advantages such as increased cure rate, reduced leachability and reduced…
X‐Ray Investigation of Stress States in Materials X‐ray stress analyses of crystalline or partially crystalline materials are based on the determination of elastic lattice strains which are converted to stresses by means of theory of elasticity. The development of the sin 2 Ψ‐method of X‐ray stress analysis and of dif…
Syntheses and room-temperature single-crystal X-ray structure determinations are recorded for 1 : 1 adducts of lead(II) nitrate with the linear multidentate polyamines ethane-1,2-diamine ('en'(= '2')), H2N(CH2)2NH(CH2)2NH2(' dien ' = '22') and H2N(CH2)xNH(CH2)yNH(CH2)zNH2 ( xyztet = '222tet' (= ' trien '), '232tet', '…
Liottite, ideally [(Na,K)(16)Ca-8][Si18Al18O72](SO4)(5)Cl-4, is the six-layer member of the cancrinite group. The structure of liottite has been refined in space group P (6) over bar to R = 2.7% using single-crystal X-ray-diffraction data. The hexagonal-system cell parameters are a 12.870(1), c 16.096(2) Angstrom. The…
Polyazamacrocyclic chelates of terbium are shown to be useful in diagnostic medical imaging as tissue site-selective markers. Spectroscopic properties and biodistribution are studied for three terbium(III) species: 3,6,9-tris(methylene phosphonic acid n-butyl ester)-3,6,9,15-tetraaza-bicyclo[9.3.1]pentadeca-1(15),11,1…
This study compares the test results of the FAST system (fabric assurance by simple testing) with those of the KES-F (Kawabata evaluation system for fabrics) for two series of twenty-two shirting materials in terms of their low-stress fabric mechanical properties of bending, shear, and tensile deformation. The first s…
Phase reaction and sintering behavior in the ternary system AlN‐Y 2 O 3 (0‐10 wt%)‐Al 2 O 3 (0‐40 wt%) at temperatures ranging from 1600° to 2000°C were studied. The density of the sintered 100 wt% A1N specimens increased monotoni‐cally with firing temperature, but the maximum value was limited to 95%, even at 2000°C…
We present experimental results of the temperature and magnetic-field dependences of the colossal magnetoresistance (CMR) and the magnetization in a series of ceramic samples with composition (${\mathrm{La}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Y}}_{\mathit{x}}$${)}_{2/3}$${\mathrm{Ca}}_{1/3}$${\mathrm{MnO}}…
Fluctuations in the number of colloid particles adsorbed irreversibly under diffusion and flow were determined. The experimental measurements were carried out in the impinging-jet cells using as model colloids the monodisperse polystyrene latex particles of micrometer size range adsorbing at mica sheets. The surface c…
An analytical study was performed to study the effect of architecture on the initiation of surface cracking in multilayer ceramic coatings. Two modes of crack initiation were considered: 1) tension resulting from stress relaxation, and 2) cyclic thermal fatigue. Transient temperature distributions were determined usin…
The oxygen surface exchange coefficient ( k ) and the self‐diffusion coefficient ( D *) of Ce 0.9 Gd 0.1 O 2 − x (CGO) have been measured using the isotopic exchange, depth profiling (IEDP) method using a secondary ion mass spectrometer (SIMS). At 486°C, D * was of the order of 10 − 10 cm 2 / s and k was 10 − 10 cm /…
Archaea possess a broader range of cell envelope structural formats than eubacteria and their cell walls do not contain peptidoglycan. Some archaea have only a single S-layer as their cell wall (e.g. Methanococcus jannaschii and Sulfolobus acidocaldarius), whereas others have multiple layers (e.g. Methanospirillum hun…
Abstract A full parametric study of the open‐loop behavior of a packed bed reactor‐recuperator system operating under periodic flow reversal produced a series of parametric maps which slow regions of operating conditions for which the system exhibits runaway, stable operation or extinction of the reaction. The reactio…
New routes for the synthesis of high Tg thermally stable polymer foams with pore sizes in the nanometer regime have been developed. Foams were prepared by casting well-defined microphase-separated block copolymers comprised of a thermally stable block and a thermally labile material. At properly designed volume fracti…
Chromatographic and spectroscopic techniques were used to investigate the degradation products from bulk oxidative and thermal stability testing of a substituted tricyclophosphazene high-temperature lubricant. Analytical investigation into the degraded lubricant revealed oligomerization to be the dominant mode of degr…
After repeated shallow discharging and overcharging of nickel or cadmium capacity‐limited cells, a working voltage lowering of the discharge curve was observed. The magnitude of the lowering was higher in the nickel capacity‐limited cells. The x‐ray diffraction pattern of the charged‐state normal nickel electrode cont…
MA'rLOCKI'I'E is a lead halide with chemical formula PbFCI. First described from Matlock, Derbyshire, UK (Greg, 1851), its crystal structure was established using the crystal-chemical studies of Nieuwenkamp and Bijvoet (1932a). On the basis of a powder diffractogram obtained with synthetic P…