Chlorophyll and related substances. Part II. The dehydrogenation of chlorin to prophin and the number of extra hydrogen atoms in the chlorins
U. Eisner and R. P. Linstead, J. Chem. Soc., 1955, 3749 DOI: 10.1039/JR9550003749
Materials Literature
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Anodic oxide films. Part 4.—The interpretation of impedance measurements on oxide coated electrodes on niobium
L. Young, Trans. Faraday Soc., 1955, 51, 1250 DOI: 10.1039/TF9555101250
Magnetostriction and Magnetomechanical Effects
The energy of a ferromagnetic substance comprises three parts, the exchange, anisotropy and magnetostatic (demagnetizing) energies. These all vary with the state of strain of the substance and so it will deform spontaneously if the deformation reduces the total energy (equal to the sum of the magnetic energy and the e…
Factors Affecting Thermal Stress Resistance of Ceramic Materials
The sources and calculation of thermal stresses are considered, together with the factors involved in thermal stress resistance factors. Properties affecting thermal stress resistance of ceramics are reviewed, and testing methods are considered.
Theory of crystallization in copolymers
The first page of this article is displayed as the abstract.
On the relations between structure and morphology of crystals. I
An attempt is made by Hartman & Perdok to find relations between crystal structure and crystal morphology on an energy basis. It is concluded that the morphology of a crystal is governed by chains of strong bonds running through the structure.
Dielectric Materials and Applications
Abstract not Available.
Electrical and Optical Properties of Indium Selenide
The electrical and optical properties of InSe have been investigated with single crystals of the compound. The spectral dependence of the optical absorption coefficient and of the photoconductivity was measured. The optical absorption edge was not sufficiently well defined for the band gap to be estimated unambiguousl…
Viscosity and the structure of molten silicates
Abstract A mgnetically controlled null-point modification of the rotating crucible viscometer has been devised which enables measurements of the viscosity of liquids to be made at maximum temperatures of 1850° C. The instrument has been applied to measure the viscosity of the system CaO -SiO2 over the composition rang…
The crystal structure of polyethylene terephthalate
Abstract The crystal structure of polyethylene terephthalate (Terylene) has been determined by the interpretation of the X-ray diffraction patterns given by drawn fibres. The unit cell, which contains one chemical unit, —CO.C6H4.CO.O.(CH2)2O—, is triclinic, with a = 4.56Å, b = 5.94 Å, c = 10.75 Å, α = 98 1/2°, β = 118…
Vulcanization Structures and Their Influence on the Heat Resistance and Fatigue of Rubber
Abstract (1) The phenomenon of stress relaxation in vulcanizates, due to thermal decomposition of the vulcanization structures, is discussed. The process follows the equation: σ t =σ 0 ⋅e −kt , where k is the kinetic constant of decomposition of the vulcanization structures, and therefore can serve as a measure of the…
Practical Loom Experience on Weavability Limits
Any one making a design for a woven fabric naturally wants to be sure in advance that the loom will weave the design. Thus, a practical designer, when first considering the use of Love's weavability graphs, is likely to ask himself: "The geometry may be all right, but how about loom performance? How closely can I expe…
Effect of molecular weight distribution on gel formation by high energy radiation
Abstract The effect of exposing long chain polymers to high energy radiation is either to produce crosslinking or chain degradation. Changes in some of the properties are outlined. The formation of gel in many polymers offers a possibility of obtaining information as to the initial molecular weight distribution. Resul…
The Alkali Orthophosphates. Phase Equilibria in Aqueous Solution.
ADVERTISEMENT RETURN TO ISSUEArticleNEXTThe Alkali Orthophosphates. Phase Equilibria in Aqueous Solution.Bernard Wendrow and Kenneth A. KobeCite this: Chem. Rev. 1954, 54, 6, 891–924Publication Date (Print):December 1, 1954Publication History Published online1 May 2002Published inissue 1 December 1954https://pubs.acs.…
Determination of thermal conductivities at high temperatures
The usual electrical methods of determining thermal conductivities either cannot be used at high temperatures or their use is restricted to substances like carbon or graphite which satisfy certain special requirements. It is shown that the observed temperature distribution along a metal filament electrically heated in…
The Absorption of Water by Woodlice
ABSTRACT Experiments were undertaken to determine the site of water uptake, and the conditions in which it occurs, in Ligia oceanica, Oniscus asellus, Porcellio scaber and Armadillidium vulgare. Besides absorbing water with moist food, all four species were capable of active imbibition of water through both mouth and…
Anisotropy of Diffusion in Grain Boundaries
Grain boundary penetrations of radioactive silver into copper bicrystals having a common cubic direction have been measured using an autoradiographic technique. Diffusion occurred along directions forming an angle φ=0°, 45°, and 90° with the common cubic direction. For very low angles of disorientation Θ, no preferent…
Thermal degradation of polymers as a function of molecular structure
\Vhen heated in a vacuum at temperatures of about 200 0 to 500 0 C, p oly mer chains break p into volatile fragments of various sizes, dependin g on t l1 e natu re of l ll e polymer. Som e ,Joly mers, like pol y -alpha-meth ylstyrene, y ield the monomer exclusively. Other polymers, like polymethylene, yield a whole sp…
Yttrium Chromium Oxide, a New Compound of the Perowskite Type
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTYttrium Chromium Oxide, a New Compound of the Perowskite TypeJohn T. Looby and Lewis KatzCite this: J. Am. Chem. Soc. 1954, 76, 23, 6029–6030Publication Date (Print):December 1, 1954Publication History Published online1 May 2002Published inissue 1 December 1954https://pubs.a…
The Preparation of Lanthanum Titanium Oxide, LaTiO31
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Preparation of Lanthanum Titanium Oxide, LaTiO31Michael Kestigian and Roland WardCite this: J. Am. Chem. Soc. 1954, 76, 23, 6027Publication Date (Print):December 1, 1954Publication History Published online1 May 2002Published inissue 1 December 1954https://pubs.acs.org/do…