Revision de Proetus (Proetus) oehlerti Bayle 1878 (Proetidae, trilobite)
Abstract At least two distinct species, Proetus baylei n. sp., Nehou, Manche, France
Materials Literature
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Thermal decomposition of cyclopentyl and cyclohexyl acetates
The rate constants k1(sec.–1) for the thermal decompositions of cyclopentyl and cyclohexyl acetates in the presence of cyclohexene are 1012·89 exp (–44,110/RT) at 315–367° and 1012·59 exp (–45,190/RT) at 337–398° respectively. The decompositions are homogeneous and unimolecular in the seasoned Pyrex vessel. The relati…
Fractographic Studies on the Cleavage Fracture of Single Crystals of Iron
A critical experiment is presented for the mechanisms of initiation and propagation of cleavage crack in iron. At first, precise fractographic observations are made on the type of the origin of crack observed on single crystals of iron with notch. A number of cleavage facets are started from the boundary of a twin, an…
The Utility of Linear Polarization Method For The Determination of The Corrosion Rate
Bu çalışma linear polarizasyon metodunun bu günkü durumunu ve bugüne kadar korozyon hızı tayinine uygulanmasını göstermektedir. Bu metodun çok pra¬tik ve faydalı olduğu gösterilmiştir. Metodun genel bir uygulama alanı göstermesi ve uygulanmasının kolay olması büyük bir avantaj sağlamaktadır. Bu metotla ko¬laylıkla kor…
On Quench Sensitivity of Cu-Cr Alloys
A study was made on the quench sensitivity of Cu-0.3∼1.5%Cr alloys. The time-temperature-precipitation curve (T-T-P curve) was drawn by plotting the electrical conductivity of specimens which were solution treated and then directly quenched over the temperature range of isothermal heat treatment. The quench sensitivit…
The Role of Wire Size in Negative Electrical Discharge at High Temperature
Negative corona onset and sparkover voltages in air are shown to be affected by temperature, density, and the pipe-to-wire ratio of radii when using concentric cylindrical electrodes. Use of large wires at high temperatures demonstrates that onset of electrical discharge occurs at voltages significantly less than thos…
Analytic Form of Stress Fields, Displacements, and Dilation for the 〈111〉Dislocation in Anisotropic Elasticity
Abstract Screw, edge, and mixed dislocations are treated by a new method which is simple to handle. Labour saving equations are derived which further shorten the algebraic processes. The results emphasize the need for anisotropic expressions in the case of common cubic materials, and are presented in a form which show…
Differential Reflection Spectra of Heavily Doped Silicon and Germanium in the Ultraviolet Spectral Region
Abstract The effect of heavy doping on the reflection spectra of silicon and germanium is investigated by measuring the fractional change in reflectance, Δ R / R , between pure and doped materials. This effect arises from the narrowing of the forbidden gap in heavily doped materials. The form of the Δ R / R spectrum a…
Metal–halogen vibrational spectra of the five-co-ordinate complexes of indium trichloride and tribromide with diethyl ether and diethyl sulphide
Low-frequency i.r. and Raman spectra of InCl3,2Et2O, InBr3,2Et2O, InCl3,2Et2S, and InBr3,2Et2S are given and interpreted in terms of D3h skeletal symmetry.
On the Magnetic Properties of Dy3+ Ion in Dysprosium Ethylsulfate Single Crystal
Abstract Principal magnetic susceptibilities of single crystal of dysprosium ethylsulfate have been computed in the temperature range of liquid‐nitrogen to room temperature, assuming that the crystal field has C 3h symmetry around the Dy 3+ ion. It is observed that magnetic anisotropy increases with the decrease of te…
Temperature Change Experiments during Secondary Creep of the Intermetallic Compound MgZn2
Abstract From temperature change experiments (between 260 and 435°C) during secondary creep of the intermetallic compound MgZn 2 an activation enthalpy Δ H = (2.25 ± 0.20) eV for basal slip has been derived. The shear strain rate γ can best be described by the empirical relation γ = 7 × 10 11 s −1 × τ 5.5 ± 1.0 exp (‐…
The Luminescence of YVO[sub 4]:Dy, YVO[sub 4]:Dy,Eu, and YVO[sub 4]:Dy,Tb
Abstract not Available.
On the Substitutional Solid-Solution Strengthening in Iron Alloys
1Fe-Mo,
Some investigations concerning the structure of ultraphosphates
Controlled hydrolytic degradation of ultraphosphate glasses at their branching sites has indicated that these compounds, with a ratio of univalent-cation to phosphorus between 0·7–1·0, consist of random arrangements of trimetaphosphate rings, polyphosphate chains, and branched chains. No ring structures larger than tr…
Evidence for the Coulomb Interaction of Be Valence Electrons by Compton Scattering Cross‐Section Measurements
Abstract The effect of Coulomb interaction on the Compton scattering cross‐section (CSCS) of a free electron gas has been calculated theoretically by Ohmura and Matsudaira within the framework of the random phase approximation (RPA). These calculations have shown that plasmon emission during the scattering process dim…
Precipitation in Beryllium-Iron Alloys
Hardness measurements and microscopic observations by both optical and transmission electron microscopy were carried out mainly on a beryllium-3wt% iron alloy.The alloy was solution-treated at 1150°C, followed by oil-quenching, and aged at 400° to 700°C for a various time. In the quenched specimens, helices and loops…
Electromotive Force Investigation of the Bismuth-Tellurium System
The bismuth‐tellurium alloy system was investigated by electromotive force measurements, coulometric titrations, x‐ray diffraction, and differential thermal analyses. The thermodynamic properties of the system have been obtained from the electromotive force measurements. The partial molar free energy, enthalpy, and en…
The Influence of Microstructure on the Fracture Topography of Titanium Alloys
A survey is presented of the fracture topography observed in titanium and titanium alloys. Ductile fracture by microvoid nucleation, growth, and coalescence is of widespread occurrence in these alloys. It is usually possible to qualitatively relate the dimple size to the macroscopic ductility of the alloy. Titanium al…
EFFECTIVE DIFFUSIVITY OF MULTI-COMPONENT GASEOUS REACTION SYSTEM
It was illustratively shown that the use of a definition of the effective diffusivity for a multi -component gaseous reaction system easily gives a sufficiently accurate approximate solution for diffusion through a stagnant gas film. In order to apply the same idea for approximate estimation of the effectiveness facto…
The annealing of graphite irradiated with electrons at 80°K
After fast electron irradiation at 80°K graphite exhibits, in its electrical resistivitiy during isochronal annealing, a reverse stage followed by normal stages. These constitute the Austerman and Hove peak. The reverse stage has previously been attributed to the separation of close Frenkel pairs of defects. In the pr…