Materials Literature
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Abstract On the basis of simple assumptions, equations are derived for predicting the specific volume‐temperature‐molecular weight ( v ‐ T ‐ M ) relationships for a homologous series of polymers from the v ‐ T curves for the monomer and the polymer of infinite molecular weight. Analogous v ‐ T ‐ρ relationships (where…
Using the method of generating function, we have discussed the shape of the absorption band and the probability for non-radiative transition of a trapped electron in insulating or semiconducting crystal, especially their temperature dependence. We have thereby chosen a model for the vibrational motion of the lattice a…
Abstract A group-theoretical treatment of the spatial symmetry of two-dimensional graphite leads to a classification of the one-electron eigenstates. The method of idempotent operators is used to derive Bloch orbitals for the crystal valence bands as linear combinations of the atomic orbitals 2px, 2py and 2s. The func…
Abstract Isobars for the adsorption of O2, H2 and CO on evaporated films of Rh, Mo, W and Fe, of Ch and CO on Ta, Pt and Pd, and of O2 on Cu, Al and Zn have been obtained. On Rh, Mo and W the rapid adsorption of O2 and H2 at -183° C results in formation of monolayers with one atom per surface atom. On Ta, Pt, Pd, Cu,…
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans the biological, physical, and social sciences.
The influence of an addition of chromium on the thermal expansion coefficient of the alloys of iron, cobalt and nickel has been determined. It has been found that in the quaternary system of iron, cobalt, nickel and chromium, there are two valleys of the expansion coefficient, one of which originates in the compositio…
The combination of high electrical resistivity and useful magnetic properties has caused ferrites to become increasingly important as high-frequency core materials. A description of the general structural and saturation magnetization properties of the more simple ferrites, and of their preparation, is followed by a br…
Abstract In some circumstances tin surfaces remain unattacked by solutions of ammonia. Factors leading to a low probability of the beginning of corrosion are: reduction in temperature of the solution, the quality of the metal surface, especially as it affects the formation of a protective oxide film in air, and also e…
(1955). Investigations Concerning Formation, Preservation and Utilization of Carotene. Acta Agriculturae Scandinavica: Vol. 5, No. 1, pp. 113-184.
M. E. Baguley, H. France, R. P. Linstead and M. Whalley, J. Chem. Soc., 1955, 3521 DOI: 10.1039/JR9550003521
A DURABILITY TEST FOR ASPHALT USING THE SLIDING PLATE (MICROFILM) VISCOMETER IS DESCRIBED AS FOLLOWS: A 5 MICRON FILM OF ASPHALT IS AGED ON GLASS PLATES FOR 2 HOURS AT 225 F. THE HARDENING WHICH OCCURS IS DETERMINED BY MEASURING THE VISCOSITY OF THE ASPHALT BEFORE AND AFTER AGING. THE DURABILITY IS REPORTED AS AN AGIN…
Abstract Das Verhältnis der Bindungsenergie (–E e ) zum Schmelzpunkt (T m ) scheint für die Alkalimetalle annähernd konstant zu sein. Dies gibt einen weiteren Hinweis dafür, daß möglicherweise T m auch anorganischen festen Stoffen korrespondierende Temperaturen darstellt. Theoretisch läßt sich zeigen, daß nach der M O…
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An experiment has been performed which leads to the conclusion that the initial permeability and radio-frequency dispersion in sintered nickel ferrite are due principally to rotation of crystallite magnetic moments in an equivalent anisotropy field. Samples have been prepared by the partial sintering of nickel ferrite…
Aluminum alloys are the anodic members of titanium‐aluminum alloy couples in dilute sulfuric acid solutions in the presence of air. In stronger acid solutions, particularly when air is absent, aluminum alloys are anodic only at the beginning of the immersion period. After an induction period titanium becomes anodic. A…
A method for electrodeposition of protective titanium coatings on steel and other base metals is described. The procedure involves electrolysis of potassium titanium fluoride dissolved in alkali or alkaline earth halides under an inert atmosphere. Graphite or titanium metal anodes are employed. Adherent titanium coati…
When the activator ions in a phosphor have a charge different from that of any ions in the host lattice, it is generally agreed that charge compensation must take place. A new theory of luminescent centres is proposed in which the compensation of charge, by lattice vacancies or by activator ions, is localized in the v…
The film responsible for passivity when iron is immersed in concentrated nitric acid is shown to be ferric acid or a related higher valence iron compound. This was proved ( a ) by demonstrating formation of chromates when a 2.84% Cr‐Fe alloy is passivated, ( b ) by showing complete suppression of the iron‐nitric acid…
Preparation of commercially pure titanium metal powder by electrolysis of in molten is described. The process is carried out under an inert atmosphere in an all‐graphite cell. Operating conditions of the electrolysis and their effect upon the metal so produced are discussed. Preparation of the and the electrolytic pro…
Research on the dielectric strength of high-voltage cables can be very conveniently carried out on "models". Either plate or cylindrical capacitors can be used for this purpose. This paper reports the results of many tests both at power frequency and at impulse, which have the purpose of investigating the separate and…