Materials Literature
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Hydrogen interaction with oxygen in copper exerts a significant influence on the apparent hydrogen diffusivity and the quantity of hydrogen absorbed. This interaction associated with steam embrittlement has been well established in alloys with high oxygen contents, such as electrolytic tough pitch (ETP) copper. Howeve…
The application for surface sensitive analytic techniques to the study of grain boundary diffusion in thin films is described. Two common experimental configurations, sputter profiling and permeation analysis, are described, as are solutions for data reduction. Analytic solutions are difficult to use, even with simpli…
A priori estimates of the suitability of a particular crystal for charge density analysis are discussed in terms of a simple criterion based on core electron concentration and a more detailed evaluation of the anticipated errors in the final deformation density maps. Predictions are compared with the results obtained…
Measurements of dipole relaxation of two types of ${R}^{3+}$-interstitial complexes in $\mathrm{Sr}{\mathrm{F}}_{2}:{R}^{3+}$ single crystals using the ionic-thermocurrents method are reported. For the light elements in the series of lanthanides we have found relaxations due to tetragonal complexes, whereas in crystal…
ATP citrate lyase was purified by two different procedures from the livers of rats first starved and then fed with a fat-deficient and high carbohydrate-glycerol diet. These enzyme preparations were judged homogeneous by sedimentation equilibrium and polyacrylamide gel electrophoresis. The molecular weight of the nati…
We have measured the optical Kerr constant and the orientational relaxation times of seven $p$,${p}^{\ensuremath{'}}\ensuremath{-}\mathrm{di}\ensuremath{-}n\ensuremath{-}\mathrm{alkoxyazoxybenzene}$ homologous compounds as functions of temperature in the isotropic phase. The observed critical behaviors near the isotro…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and characterization of new isomeric water-soluble porphyrins. Tetra(2-N-methylpyridyl)porphine and tetra(3-N-methylpyridyl)porphinePeter. Hambright, Tomiko. Gore, and Marilyn. BurtonCite this: Inorg. Chem. 1976, 15, 9, 2314–2315Publication Date (Print):September 1…
We have measured the second order β and third order γ hyperpolarizabilities of the PBLG polypeptide α-helix and find it to have an extremely large nonlinearity. The decay time of the generated harmonic has been directly determined and found to be τ=5.0 msec which is consistent with Kerr and dielectric experiments. The…
Abstract Samples of poly(vinylidene fluoride) were crystallized either (a) isothermally at a series of temperatures, or (b) in the presence of varying amounts of diluent (dimethylphthalate or dimethylacetamide). The α‐polymorph was the only crystalline form present in these samples. Melting points of the first series…
The corrosion behavior of sintered SiC in gaseous environments and alkaline melts was investigated at 900°C. In oxidizing atmospheres such as normally exist in a gas turbine, SiC forms a dense coherent surface film of SiO 2 which is not corroded by thin layers of condensed sodium sulfate. However, under some condition…
Abstract N ‐Acetylchitosan gel, a polyhydrate of chitin, and partially O ‐acetylated N ‐acetylchitosan gel were produced by a facile acetylation of chitosan with acetic anhydride in 10% acetic acid and in aqueous acetic acid/methanol at room temperature. Under the same conditions, a series of N ‐acylchitosan gels was…
Aminooxyacetate and alpha-amino-gamma-aminooxybutyrate (canaline) react specifically with the P-pyridoxal groups of cystathionase to produce characteristic changes in the absorption and fluorescence properties of the bound cofactor. The increase in fluorescence at 450 nm was used to monitor the reaction. Aminooxyaceta…
Electric field-induced deformation is studied in a unique hybrid-aligned nematic (HAN) cell, in which the director of a nematic liquid crystal (LC) with either positive or negative dielectric anisotropy is varied continuously, lying perpendicular to one substrate and parallel to the other. The experimental results sho…
Abstract Overall growth and dissolution rates of potash alum crystals have been measured over the size range 3 to 70 μm. The derived surface integration growth kinetics, which are found to be linear with respect to supersaturation and strongly size dependent, are evaluated in terms of the step model of crystal growth.…
Abstract The location of iron in five deferrated soil kaolinites and several reference samples has been investigated using chemical analyses, acid dissolution and electron paramagnetic resonance spectroscopy. The iron of most of the kaolinites can be divided into a 'structural iron' content, measured by the amount of…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe dioxygen adduct of meso-tetraphenylporphyrinmanganese(II), a synthetic oxygen carrierBrian M. Hoffman, Charles J. Weschler, and Fred BasoloCite this: J. Am. Chem. Soc. 1976, 98, 18, 5473–5482Publication Date (Print):September 1, 1976Publication History Published online1…
We describe studies of the Pt(100) – (1×1) and Pt(100) – (5×20) surfaces with LEED, UPS, AES, and flash desorption spectroscopy. The clean Pt(100) – (1×1) surface is prepared by adsorbing CO, then reacting it off with oxygen ions in the form of CO2. The clean (1×1) surface formed is metastable, converting back to the…
Abstract Thermal behavior of glasses, as observed from the isobaric variations of volume, v , and enthalpy, H , is analyzed in terms of retardation kinetics. A phenomenological theory involving a single retardation time, τ, is developed, assuming that molecular mobility is controlled essentially by the actual free vol…
Abstract The drawing behavior of a series of linear polyethylene homopolymers with weight‐average molecular weight (M̄ w ) ranging from 67,800 to ∼3,500,000 and variable distribution (M̄ w /M̄ n = 5.1−20.9) has been studied. Sheets were prepared by two distinct routes: either by quenching the molten polymer into cold…
A review of the current understanding of nitric oxide production in hydrocarbon/air and hydrogen/air combustion processes shows that the extended Zeldovich mechanism yields accurate nitric oxide predictions for fuel/air equivalence ratios from zero to infinity for hydrogen combustion and from zero to about 1.5 for hyd…