Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics and Mechanism of Vapor Phase Oxidation of Furfural over Tin Vanadate CatalystK. Rajamani, P. Subramanian, and M. S. MurthyCite this: Ind. Eng. Chem. Process Des. Dev. 1976, 15, 2, 232–234Publication Date (Print):April 1, 1976Publication History Published online1 May…
Abstract The mechanism of the thickening reaction between alkaline earth metal oxides and acid group‐terminated polyester resins was studied. The thickening can occur either by the increase in molecular weight of the resin through neutral salt formation or by complex formation between the basic salt and carbonyl oxyge…
Moldable mixtures of paraffin wax and TiO2 powders (both rutile and anatase) are easily prepared and are shown to have dielectric constants continuously variable between 2.25 and 7.5 for concentrations of TiO2 up to 35% by volume. Comparison with theory suggests that neither powder has a spherical depolarizing factor,…
A criterion for the time-dependent failure of materials is developed based upon the concept that failure results from an incremental accumulation of damage. The failure criterion is thereby explicitly tied to the incremental flow law describing the inelastic deformations. The damage increment is assumed as a product o…
Niobium crystals, with a wide range of orientations, have been deformed at temperatures where slip takes place on the anomalous (011) plane. A strong orientation dependence of the axial yield stress was observed in both tension and compression; at 77 K the stress-strain curves were serrated. Both the yield stresses an…
Abstract The change of the contact potential difference between the sample and spectrometer was examined on the adsorbed carbon/Au system by observing the low kinetic energy limit of the X-ray photoelectron spectrum. Discussions are given on the use of the contamination carbon for energy calibration.
Tests are described on new master echelles of very large size and on others having unusually high blaze angles, produced on interferometrically controlled ruling engines. Defects arising from the gravitational distortion of large grating blanks during ruling were reduced by the use of calibrated edge-supporting spring…
The lattice sums required to evaluate Madelung constants of ionic crystals are very slowly convergent if summed directly. A method is given of transforming these sums to other series which not only are rapidly convergent but involve the use of elementary functions only.
The development and testing of an ir hemi-ellipsoidal mirror reflectometer (HEMR), operational over a wavelength interval of 2-34 microm, are described. This optical system measures the hemispherical-directional reflectance of room temperature samples relative to a specular gold-coated surface. For a source and sample…
Abstract Tensile deformation of poly(methyl methacrylate) carried out under hydrostatic pressures up to 4 kbar has shown that the pressure‐transmitting fluid (silicone oil) strongly affects the mechanical properties of this polymer. Unsealed specimens fractured in a brittle manner at almost the same strain of 5% in th…
Abstract A series of 15 N labeled 2‐acylpyrroles was prepared and the nitrogen and proton n.m.r. spectra obtained. 15 N chemical shifts for these compounds are reported for the first time. No correlation between the nitrogen chemical shift and any Hammett substituent constant could be found. No variation in J ( 15 NH…
Pyridoxal 5'-phosphate labeled to the extent of 90% with 13C in the 4' (aldehyde) and 5' (methylene) positions has been synthesized. 13C NMR spectra of this material and of natural abundance pyridoxal 5'-phosphate are reported, as well as 13C NMR spectra of the Schiff base formed by reaction of pyridoxal 5'-phosphate…
The temperature dependence of the EPR frequency is calculated for antiferromagnets with inequivalent g -tensors. Contrary to the previous results for the systems with isotropic g -factor, the EPR frequency increases rapidly for every orientations of the magnetic field as the temperature is reduced. The observed temper…
Abstract For very small crystallites diffraction theory shows not only broadening of powder lines, but generally also a shift of the line position, depending on the change of the structure factor over the range of broadening. For decreasing thickness of kaolinite crystals (less than 50 layers) an increasing shift of r…
Abstract Tensile properties of injection and compression molded ABS, terpolymer of acrylonitrile, butadiene, and styrene, were measured as a function of aging time at 40 to 90°C. Both air and nitrogen atmospheres were employed to separate the oxidative and thermal effects. Results demonstrate that tensile elongation i…
The equilibrium phases in the lithium sulfide‐ferrous sulfide system were determined by differential thermal analysis and x‐ray diffraction analysis. A compound Li 2 S · FeS , which melts incongruently at 885 ° ± 5 ° C to Li 2 S , and a liquid containing approximately 50.5 mole per cent ( m / o ) FeS , and has a trans…
Abstract This paper concerns the action of plasticizers and nucleating agents on the crystallization of bisphenol‐A polycarbonate. The influence of plasticizers is to increase the rate of crystallization to a great extent using 10 percent of a plasticizer such as trimellitic acid, tridecyloctyl ester. The influence of…
The three lowest energy levels of ${\mathrm{Ho}}^{3+}$ in ${\mathrm{LiYF}}_{4}$ are determined by submillimeter EPR spectroscopy. The ground state is a ${\ensuremath{\Gamma}}_{3,4}$ doublet. The next excited levels are two ${\ensuremath{\Gamma}}_{2}$ singlets at 6.8 and 23.8 ${\mathrm{cm}}^{\ensuremath{-}1}$. The ${g}…
The reflection spectra of BiI s single crystals were measured between 1.5 and 5.5 eV at 6, 77 and 286 K. A Kramers-Kronig dispersion analysis of the data was made, and the intrinsic absorption coefficient and the real and imaginary parts of the dielectric constants were calculated. The large peak at 2.0 eV is ascribed…
Unpolarized specular reflectance spectra at near-normal incidence were measured in the silicates olivine, pyroxene, spinel and Al-garnet in the photon energy range 4–14 eV at 300°K, and the optical and dielectric functions were obtained from the reflectance by Kramers-Kronig analysis. The spectra indicate that these m…