Materials Literature
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The present paper deals with the description of 60 pollen and spore species found in Palaeocene sediments of the Chubut Province, Argentina. The material was collected from several sections of the Salamanca Formation (Cerro Abigarrado, Puerto Visser, Bajada de Hansen) and from other sections of the Bororo Formation. A…
Experiments were conducted with pitting corrosion of the ends of titanium rods insulated on the sides with epoxy resin. The rods were potentiostated in the anode‐facing‐up position in chloride, bromide, and iodide solutions. After a small depth of corrosion a uniform current density was obtained characteristic of one‐…
A survey is given of electric alignment in liquid crystals, emphasizing electro-optical effects and the physics behind them.
When iron–vanadium–carbon alloys are transformed from the γ to the α state, a banded dispersion of vanadium carbide is formed as the transformation fronts move through the crystals. The strengthening resulting from this reaction in a series of alloys isothermally transformed in the range 725–850° C is shown to be depe…
The paper discusses the dependence of γ-the coefficient of potential emission of electrons from metals on the work function ϕ and Fermi energy εF for metals and the ionization energy of ions Ei . It has been found that in the range 3ϕ <Ei<2(∊F+2ϕ) Deviations from this dependence exceeding 10% have been observed at Ei<…
Experiments were conducted in which pitting occurred at the edges and on the circumference of holes in titanium foil in chloride, bromide, and iodide solutions under potentiostatic conditions. Valence of dissolution was approximately 4. The effect of potential, temperature, concentration, p H, and solution flow on cur…
The Profile Analysis technique for neutron powder diffraction patterns has been used to show that the lowest temperature phase of barium titanate is rhombohedral R3m with cell angle α = 89.868 ± 0.004°at 77.4 K. The atomic displacements from the cubic perovskite positions are along [111], and have magnitudes of δ (Ba)…
The Onsager theory for the liquid crystal phase transition of a gas of hard rods is known to be accurate if the rods are long enough. In order to quantify the necessary length, the first correction term (the third virial coefficient) to the Onsager theory is estimated numerically. On the basis of a study of the behavi…
The peel strength of rubber and paint films has been measured over a range of peeling velocities using a dead weight method. At low peel rates the peel force is fairly constant but rises rapidly at higher peeling speeds. Experiments show that the peel strength is a function both of the energy of interfacial bonds whic…
The structure of the ferro electric phase of Triglycine Sulfate has been refined from neutron diffraction data. The hydrogen bonding scheme proposed by Hoshino, Okaya and Pepinsky2 has been confirmed. The short hydrogen bond between glycine II and glycinium III that has been postulated to cause the transition has been…
1. A Brief History. 2. Glass and Glass Fibres. 3. The Products and Manufacturing Processes. The products. An outline of the manufacturing processes. 4. Glass Manufacture. Glass compositions. Selection of raw materials for E glass manufacture. Handling, weighing, and mixing of raw materials into batch. Production of E…
~~~~~~~c~t;;m~+C~+ NAY-+ 3 and D-1-amino-2-propanol dehydrogenase F? D 1 amino-2-propanol + NA&. Each enzyme has been obtained in purified form free of the other; the nature of the reaction catalyzed by the latter dehydrogenase alone and in a coupled system with the former enzyme has been studied. The results provide…
The possibility of creation of a structure of two domains with mutually opposite directions of spontaneous polarization is considered. These domains are divided by a domain wall of metal conductivity with a concentration of free electrons or holes of about 1021 cm-3, the thickness of the conducting layer being about 1…
The method of nuclear microanalysis of stable oxygen isotopes by the reactions was used to investigate the mechanisms of growth, dissolution, and transport associated with oxygen during the formation of relatively thin (≤7000Aå) porous anodic layers on aluminum. The average charge associated with an oxygen ion fixed i…
Abstract The nucleating activity of a large number of nucleating agents for the crystallization of polyolefins is not based on a high surface free energy of the substrate or on epitaxy, or on a minimum particle size just compatible with the thickness of the crystallizing polymer lamellae, or on any persistance of crys…
Structure and properties of disclination lines and disclination points in nematic and cholesteric liquid crystals are reviewed. An equivalence between the directorfield of nematics and electrostatic or magnetostatic fields in two-dimensions is pointed out. Dislination lines can be classified in singular and non-singul…
The electrical conductivity of sintered specimens of CaO ‐ doped CeO 2 [ 0.1 – 16.0 m / o ( mole per cent ) ] was measured over the temperature range 700°–1500°C and from 1 to 10 −22 atm of oxygen. All specimens of CaO ‐ doped CeO 2 exhibited mixed conduction. Two limiting case regions were observed. At low temperatur…
Core binding energies of a number of nitrogen bases and their adducts with BF3 are reported, and interpreted using both ab initio and semi-empirical molecular orbital calculations. The binding energies are found to reflect the change in molecular charge distribution which occurs on formation of the B—N σ bond. The cor…
The system has been studied by a combination of polarization microscopy, using a hot stage, and X-ray diffraction analysis. The sequence of condensed phases occurring at room temperature with increasing concentration of disodium chromoglycate (DSCG) is: (i) a mesophase N; (ii) a mesophase M; (iii) crystalline solid so…
Single-crystal X-ray studies have shown the trishexamethyldisilylamides of scandium(III) and europium(III) to have unusual pyramidal three-co-ordinate structures.