Materials Literature
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The x-ray-induced ‘‘blue’’ emission from commercially available, high-quality synthetic quartz has been studied between 80 and 300 K. Three overlapping bands, each having a different quenching temperature, have been experimentally resolved in the as-grown crystals. These bands peak at 440, 425, and 380 nm; their half-…
Abstract The LO‐phonon—plasmon coupling in n‐ZnO single crystals is investigated by Raman spectroscopy at room and liquid nitrogen temperatures. The energy shift and halfwidth broadening of the LO‐phonons relative to the uncoupled modes are analyzed to get the concentration and mobility of the charge carriers. These r…
Pyrochlore structure oxides described by the formula , where , , and , have been evaluated for oxygen electrocatalysis. In alkaline electrolyte between room temperature and 110°C, these materials display significantly lower polarizations than any other catalyst for evolution and are among the best for reduction. Rotat…
Summary A range of extractants commonly used in soil studies, both to clean up the crystalline clay minerals by dissolving poorly ordered phases, and to assist in the classification of soils, has been used to assess their efficiency in extracting inorganic forms of translocated Al, Fe and Si from a podzol Bs horizon.…
Hydrogen trapping in AISI 4340 steel was investigated by thermal analysis at a constant heating rate of 3·4 K min−1. Peaks were observed in the evolution rate v. temperature plots at 388, 545, 611, 678, and 768 K in AISI 4340 steel samples having either pearlitic or spheroidized carbide structure, and analysis suggest…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSonochemistry and sonocatalysis of metal carbonylsKenneth S. Suslick, James W. Goodale, Paul F. Schubert, and Hau H. WangCite this: J. Am. Chem. Soc. 1983, 105, 18, 5781–5785Publication Date (Print):September 1, 1983Publication History Published online1 May 2002Published ini…
At Ni or Raney Ni Al‐type electrodes subjected to cathodic polarization with evolution in alkaline solutions, characteristic time dependent currents are observed when measurements are made in the direction of increasing or decreasing potentials. Also, after polarization to high cathodic overvoltage, appreciable quanti…
This paper examines the non-linear elastic behavior of fabric composites. Three types of non linearity including the shear deformation of fill threads, the extensional deformation of the pure matrix regions and transverse cracking of the warp regions have been taken into considerations. The non-linear constitutive rel…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSurface characterization of copper(II) oxide-zinc oxide methanol-synthesis catalysts by x-ray photoelectron spectroscopy. 1. Precursor and calcined catalystsYasuaki Okamoto, Kiyotaka Fukino, Toshinobu Imanaka, and Shiichiro TeranishiCite this: J. Phys. Chem. 1983, 87, 19, 37…
The intrinsic crack tip processes of either propagation by cleavage or blunting by the nucleation of dislocations from the nonlinearly stressed region at the crack tip have been simulated by a molecular dynamics approach in alpha-iron and in copper, utilizing the Johnson and Morse potentials, respectively, and a new f…
Electron-energy-loss spectra have been measured in the region of the $K$ edges in graphite and hexagonal boron nitride. The fine structure is found to be strongly dependent on the crystal orientation and momentum transfer. Angular distributions of peaks in the spectrum have been recorded from crystals with the $c$ axi…
Abstract As a nondestructive method of evaluation, we have used integrated optics to investigate thin films (<8 μm) of polyamic acid and polyimide as a function of molecular weight, initial imidization temperature, method of imidization, and annealing treatment. Polyamic acid films were found to exhibit a large opt…
We have developed a computer program by means of which a two-dimensional soap froth may be simulated. This system is of interest in connection with theories of grain growth in polycrystalline solids, but only limited and somewhat contradictory experimental statistical data have hitherto been available. We present prel…
Two industrial portland cement clinkers from the same kiln, with different setting rates, were texturally characterizated by reflected light microscopy. They showed remarkable mineralogic and textural differences which arised during their distinct cooling processes, according to the interpretation of their textures.
Physical properties of Villamayor sandstone (Salamanca), and especially porosity, water absorption and capillary flow through rock are studied in relation to its lithological characteristics. Laboratory weatherability tests (wetting-drying, freezing-thawing, and salt crystallisation) shows the susceptibility to destru…
The present paper deals with aspects concerning the conditions to be fulfilled by raw materials and manufacturing process of cements containing components other than clinker and setting regulator. It deals also with proper conditions for the utilization of these cements, as well as with the knowledge of the interrelat…
A comparative study has been done about the use of three methods: Microscopic, Dissolution of Phases and X-Ray Diffraction, for the determination of the mineralogical composition of clinker, XRD appears (just as it is shown in this paper) as a complicated method which does not guarantee a good determination of C3A. Th…
This discussion commences with some general comments on the energy crisis and its impact on the cement industry, with the corresponding coal reconversion problems. Three factors are highlighted where saving has been centered: technological process, raw materials and finished product, emphasizing the interest of latter…
There having been established in a previous publication the criteria which guide the designing of a system of simulation, in this work is presented the carrying out, in our Department, of a versatile installation, of a modular type which allows, in its whole, to carry out a large part of the experiments of alteration…
In this work, which is a follow-up of others, the evolution of structural features of enriched fraction (attacked-hydrated cement) is studied by DRX, extracted from one of the mortar prims (1 : 3) of 1 X 1 X 6 cm of the various series of test specimens made with a Portland cement (cement 3) and mixtures cement 3/slag…