Materials Literature
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A Kerr magneto-optic apparatus has been used to observe the effects of tensile stress on the domain structure in grain-oriented 3.25% silicon steel. Unlike the powder pattern technique, the Kerr apparatus reveals the complete surface domain structure without regard to the type of domain wall, and enables observation o…
Summary Nickel carbonate occurs in nature as a hexahydrate (hellyerite) and as a hydroxyhydrate (zaratite), but the anhydrous species is only known as an artificial product. All of the compounds show anomalous properties that have led to confusion in the literature. Only the calcite structure was found for NiCO 3 ; hy…
The influence of milling upon some magnetic properties of the intermetallic compound MnAlGe has been studied. The Curie temperature of the material seems to be independent of particle size and is constant at 245°C. The saturation magnetization σs, which is 55 erg/Oe·g in the annealed state, decreases as the grinding t…
The quenching technique has been used to determine equilibrium relations in the system manganese oxide‐Cr 2 O 3 in air in the temperature range 600° to 1980°C. The following isobaric invariant situations have been determined: At 910°± 5°C tetragonal Mn 3 O 4 solid solution, cubic Mn 3 O 4 solid solution (=spinel), Mn…
An improved counterbalanced sphere viscometer—densitometer was used to obtain density information between 1050° to 1500°C for a series of binary germanate melts containing as much as 60 mole% Li2O, Na2O, K2O, and Rb2O. Densities and the expansion coefficient of molten GeO2 between 1100° to 1400°C were estimated from t…
A study has been made of high-resolution absorption spectra of C 12 S 2 and C 13 S 2 in the region 4300–3300 Å. The spectra are shown to arise from transitions from the ground state to two or more excited electronic states. In the lowest excited state the molecule is not linear, and the following constants have been d…
Molecular iodine was removed from polypyrrole by electrochemical reduction of slurries at a mercury cathode. This method was found to be more effective than the treatment of rigid or packed polymer electrodes. Voltammetric plots indicated that two reductions occurred, at potentials insensitive to pH. The current passa…
Abstract The tensile stress at break (σ b ) and the associated ultimate strain (ϵ b ) of an elastomer depend on (1) the chemical and topological characteristics of the polymeric network, and (2) the test conditions under which rupture is observed. To separate these effects, the ultimate tensile properties can often be…
The effect of a uniform magnetic field on the mechanism, kinetics, and resulting morphology of a spinodally decomposing alloy is investigated. It is shown that the magnetic field is most effective in forming uniformly spaced rods parallel to the magnetization if the aging is carried out just below the intersection (on…
The viscosity of supercooled water has been measured, using a capillary flow technique, down to -23.8 °C. The large supercooling was obtained by removing nearly all suspended particles from the water by an ion exchange column. These results agree with those obtained by White and Twining in 1914, who obtained results d…
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The electron spin resonance absorption and electrical resistivity have been measured under rigorous conditions for a series of polypyrroles prepared over the temperature range 120-500°. When plotted as a function of pyrolysis temperature the resistivity shows a maximum in the region 200-300°. Although the resistivity…
The pyrolysis of tetraiodopyrrole in an inert atmosphere at temperatures from 120-700° yields black, infusible, amorphous polymers insoluble in solvents. Depending on the pyrolysis temperature, iodine may be present in the polymers as iodine of substitution and as chemisorbed molecular iodine, which is very tenaciousl…
Viscosities of synthetically hydrated obsidians have been measured by the falling-sphere technique at two values of the H2O content. At 4.3 per cent H2O, by weight, the common logarithm of the viscosity in poises ranges from 6.51 at 800°C to 5.88 at 900°C, and at 6.2 per cent H2O from 6.54 at 700°C to 5.25 at 850°C. T…
The frequency-dependent complex dielectric constant $\ensuremath{\epsilon}(\ensuremath{\omega})={\ensuremath{\epsilon}}_{1}+i{\ensuremath{\epsilon}}_{2}$ and associated functions are derived in the range 0 to 22 eV by application of the Kramers-Kronig relations to existing reflectance data for clean Al surfaces. The r…