Materials Literature
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Octahedral ferrous chelates based on the hydrotris (1-pyrazolyl) borate ligand can be prepared which are fully high spin, or are fully low spin, or have an intermediate magnetic moment which is strongly temperature dependent. Mössbauer and magnetic susceptibility data characterizing this behavior in the solid state ar…
These experiments were designed to determine the degree and kind of variability in the structure of the community that one might expect under very similar ecological conditions. The results of these experiments show that 95.5% to 98.0% of the specimens composed the same species in the eight communities. About 5% of th…
Abstract The dynamic mechanical properties of a polyimide (poly‐4,4′‐oxydiphenylene pyromellitimide) were studied from about 4 to 800°K. at audio frequencies. A prominent relaxation associated with absorbed water content occurs near 230°K. Below 270°K., the modulus undergoes a corresponding increase in value with incr…
Summary Red soils representing the major groups in which iron oxides are thought to exert a favourable effect on physical properties, have been treated with Na‐dithionite and citrate, or Na‐dithionite and 0.05 n HC1. These treatments removed the free iron oxides and some aluminium oxides and silica. Changes in the phy…
We have observed an anisotropic EPR spectrum in a frozen solution of the low-spin (S = 12;) hemoprotein ferricytochrome c. These results are interpreted in terms of the theory for the low-spin ferric ion in an octahedral crystal field which is subject to an (axial) distortion along the axis perpendicular to the heme p…
Cobalt was deposited in ultra-high vacuum onto (001) copper surfaces prepared inside the vacuum chamber. If the copper substrate was at room temperature during film growth then the cobalt grew approximately as a monolayer. The structure and lattice parameter of the cobalt remained the same as the copper until its thic…
The effect of pH on the spontaneous-passivation characteristics of AISI Types 304, 430 and 410 stainless steels has been studied by means of anodic-polarization and potential-time techniques. An inverse linear relationship between the logarithm of the critical current density for passivity and pH was found to hold tru…
Salt pollution on outdoor insulators has been a serious problem in Japan, and steady efforts have been made to prevent flashover faults on polluted insulators. As a part of such efforts, a simple method of artificial pollution test has been developed to evaluate the flashover characteristics of polluted insulators, es…
Abstract Unsteady‐state water sorption measurements have been carried out over the temperature range 27–40°C. on a polyurethane elastomer composed of MDI, 1,4‐butanediol, and polybutylene adipate (MW 2000) in the mole ratios 3.2:2:1. The sorption isotherm is concave upward above an activity of 0.6, reaching a saturati…
Polarization studies were carried out both at an iron electrode and an iron electrode having a surface layer of cementite. Anodic and cathodic polarization curves were compared in nitrate and chloride solutions and the effect of temperature and the addition of acid was examined also. The Fe3C electrode was found to un…
A method has been developed for obtaining lattice spacings of powder samples by x-ray diffraction in times potentially as short as 1 second. The sample is irradiated with polychromatic radiation from an x-ray tube, and the energy spectrum of x-rays scattered at a given angle is observed with a semiconductor radiation…
Twenty-one species (23 isolates) of marine diatoms were examined for their capacity to utilize analogs of cyanocobalamin for growth at the ecologically significant concentration of 4 ng 1-(1) . Yields due to the analogs were compared to those produced by B12 . Responses of the various clones to the analogs were not al…
The Arbuzov reaction of cotton fabric containing the haloacetamidomethyl groups Cell-OCH 2 NHCOCH 2 X (X=I, Br, Cl) has been studied systematically to prepare new cellulose phosphonate ester derivatives. Comparison of flame-retardant properties of the phosphonate derivatives with those of fabric containing a deposited…
Epitaxial twinned single-crystal films of copper have been grown on sapphire substrates by high vacuum evaporation in the temperature range 240–-375°C. The presence of a twin relationship in copper deposited on the basal plane of sapphire was demonstrated and evaluated by x-ray diffraction techniques. The epitaxy has…
Abstract In the last few years several reviews and books have been published on the aging of elastomers, but the overall view which they present of the oxidation of natural rubber and its vulcanizates still contains many puzzling features. Two of these are the variation of antioxidant efficiency in different types of…
Abstract The first synthetic rubber manufactured in the United States was of the polysulfide type. In 1927 Patrick and Mnookin had obtained the first of a series of patents on the products from the reaction of organic dihalides and inorganic polysulfides. Production was started in Kansas City in 1929 with the first of…
Polymer dielectric films, ranging in thickness from less than 100 A to several microns, have become increasingly useful for basic investigations of surface phenomena and thin film electrical conductivity and for thin film electronic device and circuit development. The preparation and characterizing properties of thin…
Liquid silicates, in common with phosphates and probably other oxygen‐containing inorganic polymers which are stable at high temperatures, contain in general a multitude of anionic species ranging in size and complexity from simple “monomeric” groupings such as SiO 4 4− and P0 4 3− to continuous, cross‐linked networks…
Ultrasonic shear and longitudinal measurements were made in Bz03 from 650° to 1000° C. From these data both the shear and volume relaxation time spectra were determined. The spectra had the same temperature dependence, although the volume spectrum was always broader than the shear spectrum. The shear relaxation proces…
The dielectric constant and loss of eight isomeric octanols has been measured over a wide range of temperature and frequency. Two distinctly different types of dispersion loci are found: For those alcohols whose –OH group is so sterically hindered that association into linear chains is unfavorable, a very small, very…