Materials Literature
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Oxygen‐18 enriched oxygen and carbon dioxide‐carbon monoxide atmospheres have been used in the determination of the oxygen self‐diffusion coefficient in monoclinic zirconia at 990 °C. Oxygen exchange measurements were made on zirconia spheres in the average size ranges of 90 and 126µ. The diffusion coefficient was fou…
High‐temperature x‐ray and DTA investigations of the lead oxide‐lead sulfate system confirmed the phase relations established by Esdayle and Lander. In order to elucidate discrepancies in the literature and to insure positive identification of the three basic lead sulfates , , and , single crystals were prepared and i…
Abstract These studies were undertaken to determine the thermal behavior of structurally related polymers having a carborane nucleus in the recurring unit. Three of these products also contained phthalocyanine rings in their molecules. Results of thermal analysis studies show generally that the relative heat stability…
The efficiency of TiO2 as a nucleating agent in the Li2O—Al2O3—SiO2 system is explored over a wide composition range. Sharp changes in crystal growth rate, which strongly influence nucleation rate, are observed near the Li2O·Al2O3—SiO2 composition line and are ascribed to changes in fluidity of the glass at the crysta…
The initial phase of the reaction between powder and liquid has been investigated. Electrophilic attack by protons in the liquid results in the decomposition of the powdered glass with liberation of cations and fluoride ions. The extent of the attack depends on the degree of acidity of the liquid.
Methyl fluorosulphonate N-methylates octaethylporphyrin and octaethylchlorin to give, depending upon the reaction conditions, N-methyloctaethylporphyrin, two NN′-dimethylporphins, NN′N″-trimethylocataethylporphin, and an N-methyloctaethylchlorin.
Titanium alkoxides react readily and reversibly with isocyanates by insertion into the Ti–O bond to form mono-, di-, tri-, or tetra-N-titano-urethanes. With titanium aryloxides the reaction is much slower and irreversible. Carbodiimides react in a similar manner to give only the di-substituted-N-titanoisoureas. The re…
The lattice vibration of anharmonic or “non-ideal” solids is studied using a method of double-time Green's function, without assuming the smallness of the anharmonicity of atomic vibrations from the outset. To encompass disordered and amorphous solids and molecular systems as well, a system under consideration is take…
(1970). Criteria for an Optimum Human Environment. Bulletin of the Atomic Scientists: Vol. 26, No. 1, pp. 2-6.
Direct analysis of the separated phases in unmixed sodium borosilicate glasses has been carried out using an electron microprobe analyzer. The results are discussed in relation to the tie-lines proposed by Charles, Tran, and Mazurin.
The vibrational spectra of eight alkoxysilanes, (RO)3SiH (R = Me, Et, Prn, Pri, Bun, Bui, Bus, and But), have been recorded, allowing tentative assignments of the various modes to be made. Trends observed in these spectra are discussed and compared with those found in related compounds.
During an isothermal anneal of an ion-bombarded UO2 thin foil, electron microscope observations were made of the self-climb velocity of dislocation loops prior to coalescence. A model for loop movement by self-climb has been constructed and two interactions considered to act as the driving force. First, the mutual int…
Abstract By slow neutron inelastic scattering the phonon dispersion relation was measured in potassium fluoride at room temperature for waves propagating along symmetry directions [00ζ], [ζζ0], and [ζζζ]. The experiments were performed on the reactor Diorit at Würenlingen, using a triple axis spectrometer. The results…
Red-degraded bands observed in absorption in the region 3600–3900 Å when strontium sulphide is heated in a carbon tube furnace to about 2000°C are assigned to a 1Σ+–1Σ+ system of SrS. The lower state is probably the ground state : the upper state is strongly perturbed. Constants derived from the analysis of five bands…
Abstract The role of clay minerals in influencing the polymerization of organic monomers can be ascribed to a charge transfer between the clay and the adsorbed species. Polymerization may be either initiated or inhibited by the clays.
Abstract not Available.
Oxidation and reduction processes of silver‐silver oxide electrodes were studied, especially the influence of light excitation on these processes. The experimental results have shown that light absorption by silver (I) oxide leads to an anodic oxidation to silver (II) oxide. The electrochemical reduction of silver (II…
The single-crystal polarized spectrum of [(Ph2MeAsO)4CoNO3]+NO3– has been recorded at 300, 77, and 20 K and principal magnetic susceptibilities of single crystals measured in the range 300–90 K. These properties have been interpreted within a point-charge crystal-field model and the results compared with those for the…
The polarised single-crystal electronic and e.s.r. spectra of 2,2′-bipyridylbis(hexafluoroacetylacetonato)copper(II) have been measured. The correlation of the single-crystal electronic and e.s.r. spectral data with the crystallographic data indicates a dxy ground state. The polarised single-crystal electronic spectra…
The antibacterial activity of methanol extract from the root bark of Akanda (Calotropis gigantea L.) and its petroleum ether, chloroform and ethyl acetate fractions were investigated. Both of methanol extract and its chloroform fraction showed activity against Sarcina lutea, Bacillus megaterium and Pseudomonas aerugin…