Materials Literature
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The crystal structure of ε -Mg 2 PO 4 OH ( Pnma , a = 8.239(1), b = 6.135(1), c = 7.404(1) Å, Z = 4) was solved by direct methods and Fourier syntheses and refined to a final R -value of 0.017 for 637 high-angle reflections. Slightly distorted trans -MgO 4 (OH) 2 octahedra form chains along b by edge-sharing, the chai…
As part of its program in mineral waste management, the Bureau of Mines has investigated the effect of ion exchange on the dewatering potential of clay minerals. Clays of the smectite group possess exchangeable cations to compensate for the overall net negative charge of the clay lattice. The ratio of the valence of t…
The flame spread rates of paper sheets, in which powder retardants were applied, were measured. Retardant compounds utilized were NaHCO3, Na2CO3, water, urea, NH4H2PO4, and HPO3. This paper forcuses mainly on the effectiveness of NaHCO3. As NaHCO3 content in the paper sample increased, the spread rate (2.5 mm/s) by fl…
This paper describes a straightforward, well-defined heat stability test for stabilised or unstabilised PVC powder in which a sample is heated in a U-tube in a controlled environment and the quantity of HCl generated measured using a conductivity cell. As long as the prescribed precautions are followed the method has…
Previous experiments have demonstrated that halfwave overcoats of a low-index coating material are effective in increasing the damage thresholds of dielectric high reflector coatings (HR's) at the wavelengths of 1064 nm and 248 nm. This overcoat layer led to a 50% increase in damage threshold at 1064 nm and to a 100%…
Les cristaux de ZnS obtenus à partir de la phase vapeur à environ 1450°C ont la structure hexagonale 2H. Des transformations à l'état solide au cours du refroidissement sont à l'origine des polytypes observés, dont une liste est donnée. La stabilité de la température et de la pression au cours de la croissance est une…
Abstract The backscattered electron (BSE) signals detected by a pair of detectors in the SEM can be used for producing colour micrographs. The image corresponding to any of these signals, or to a mixture of these signals, is assigned one primary colour and two or more of these images are superimposed onto the same col…
The predicted and calculated configurations of the [001] twist boundaries in rocksalt-structured oxides have been reanalysed in terms of arrays of screw dislocations. The dislocation model is then used to predict the structure of all [001] twist boundaries in these oxides. A computer simulation confirmed the stability…
Catalytic reductions of N2O and NO by CO to N2 can be achieved at 100 °C in solutions containing Rh2(CO)4Cl2 and a base: the highest rate for the N2O reduction of 25.2 turnovers per hour in dimethyl sulphoxide was obtained using KOH as the base.
Experiments on Al2 + ZrO2 ceramics reveal higher Young′s moduli and fracture toughness after sintering in air then in hydrogen. Since X-ray measurements showed a higher monoclinic phase content in the air-sintered material, Young′s moduli of these ceramics indicate the existence of higher residual stresses associated…
The combination of metallic fuel and stainless steel cladding in a fuel element forms a complex multicomponent diffusion couple at elevated temperatures. Interdiffusion of fuel and cladding components can in principle lead to several phenomena that could affect the reliable performance of a fuel element. These phenome…
A new relationship for predicting the gaseous gap conductance between the fuel and clad of a nuclear fuel rod is derived. This relationship is derived from purely analytical considerations and represents a departure from approaches taken in the past. A comparison between the predictions from this new relationship and…
ガウス-ローレンツ複合関数に非対称項を導入し,X線光電子スペクトルの波形を解析した.非線形最小二乗法によりスペクトルのカーブフィッティングを行ったところ,ガウス-ローレンツ関数は高度の適合性を示し,白金でモリブデンの金属成分の非対称なピークや酸化状態による対称性の高いピークのいずれに対してもよく表すことができた.更に,最小二乗法におけるパラメーター間の制約について検討を加えた.
The synthesis is described of a porphyrin alcohol (22) which has a structure very similar to that of porphyrin a(2). The model porphyrin was resolved by separation of its camphanate esters. Ozonolysis of the 2-nitrobenzoate of each enantiomer in tritiated form gave a derivative of 2-hydroxypentanedioic acid whose conf…
Abstract Optical metallography, one of the most common materials characterization techniques, uses visible light to magnify structural features of interest. This article discusses the use of optical methods to evaluate micro and macrostructure and relate it to process conditions and material behavior. It covers the st…
A new method is described for embedding stained tissue sections, cells, cultured cells or organ cultures in a special polyethylene mold to form epoxy microscope slides (cast-a-slides). Cast-a-slides in which biological specimens are embedded may be examined by light microscopy and individual optimally stained cells or…
Flory–Huggins interaction parameters, χ12, have been determined for tetrahydrofuran–benzene, benzene–polytetrahydrofuran and tetrahydrofuran–polytetrahydrofuran mixtures from static vapour-pressure measurements. Values of χ lie between –0.18 to –0.23 for the first system in the temperature range 10.0–35.0 °C. The seco…
Abstract The degradation of adhesive strength between plies in aircraft tires was studied as a function of aging temperature, time, and environment. Adhesive strength degraded much faster than the cord tensile strength under the aging conditions used. Adhesive strength degraded faster in air than in nitrogen during th…
Abstract Electroformed nickel tubing was deactivated by chemical vapor deposition of silicon from silane gas and subsequent treatment with cyclooctamethyltetrasiloxane (D4). Standard activity tests performed on the uncoated tube and also on columns coated with crosslinked and uncrosslinked, nonpolar stationary phase,…
This thesis presents the results of an experimental study of three 1/3 to 1/2 scale model walls failing in shear under reversed cyclic loading. The main test parameter was the wall aspect ratio (height over length) . The following characteristics of response were considered: strength, displacement ductility, energy di…