Materials Literature
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The crystal structure of AgNa(NO2)2 has been determined at 50°C in the paraelectric phase (space group Fddd), and work at 20°C on the ferroelectric phase (space group Fd2d) is in progress. The unit cell contains 8 formula units. The paraelectric structure is partially disordered and each NO2 molecule has two stable po…
Practical rubber formulations are complex mixtures of polymer (s), fillers, plasticizers, curatives, and processing aids. Classical methods exist for determining many of the components of these systems but are too time consuming for routine use in quality control or problem solving activities. Thus a need has existed…
[in Japanese]
Variable-temperature n.m.r. spectra of a series of In, Ru, and Ti complexes of substituted tetraphenylporphyrins show that phenyl ring rotation occurs on the n.m.r. time scale if the phenyl ring ortho-substituents are hydrogen.
Stern-Geary and Tafel polarisation relationships have been obtained for steel in 0·5 M H2SO4 and 1 M HCl containing different concentrations of a wide range of n-alkylquaternary ammonium compounds and thiourea derivatives. The shape of the Stern-Geary polarisation relationship is found to depend on the difference betw…
Abstract
Many mesomorphic compounds undergo decomposition on repeated heating. In the search for compounds which are appreciably stable to heating cycles and which display mesophases over a wide range of temperatures, we have prepared some biphenyl-4-trans-p-n-alkoxycinnamates and have investigated their mesomorphic properties…
Zircaloy-2 having several different microstructures, textures, and compositions has been bombarded with either 5 MeV or 46.5 MeV nickel ions at 300 to 600°C to achieve doses ranging from 0.65 to 87.0 displacements per atom (dpa). Similar material was reactor-irradiated near 320°C to neutron fluences between 0.8 and 3.…
Measurements have been made which show that there is no predictable connection between fibre swelling and the plasticisation of acrylic fibres. The diffusion of dyes into the fibres is controlled by the segmental mobility of the fibrous polymer chains and not by fibre swelling.
The temperature dependence of the lattice constant of SrTiO3, in particular around the 106 K transition, has been measured by using a double-crystal X-ray diffraction method; a relative accuracy of 10−5 is attained. The results are compared with those of EPR in terms of static rotation ø of TiO6 octahedra around [001]…
The anomalous behaviour of powdered barium titanate is confirmed by the use of the formula for mixtures. Systematic measurements of the dielectric properties of BaTiO 3 have been done for two cases: embedded grains and fine-grained pressed powder. The influence of the size and shape of the grains, and of the method of…
20% cold worked Type 316 stainless steel in the form of uniaxially stressed solid rod and pressurized tubes was irradiated at 450°C in the EBR-11. Five irradiated and three unirradiated specimens were examined by transmission electron microscopy to determine the effect of stress on microstructure and possible mechanis…
Four new borates of the formula X 2 Z ( BO 3 ) 2 , with X = Ba , Sr , Ca , and Z = Ca , Mg , are described. Ca 2 Mg ( BO 3 ) 2 is tetragonal, and Ba 2 Mg ( BO 3 ) 2 is hexagonal and isomorphous with the mineral buetschliite. Ba 2 Mg ( BO 3 ) 2 and Sr 2 Mg ( BO 3 ) 2 are related to buetschliite but their diffraction pa…
The presence of a variety of polysilicates, including branched chain species, in aqueous sodium metasilicate solutions has been shown by 29Si n.m.r.
Galvanic cells of the form where varied between 0.9 and 1.2 were operated at 120°C, and currents of 50 mA/cm 2 could be drawn. The cells were electrochemically regenerative, and the cathodes could be thermally regenerated. Initial open‐circuit voltages varied between 2.37 and 2.45V. Cells were discharged at constant c…
Field induced reversible transitions between AFE and FE phases of PLZT ceramics are considered to realize a high contrast image storage and display device. The proposed field-induced phase transition takes the material from a non-scattering AFE phase to a scattering FE phase, and returns the material to the original A…
Samples of the metallic spinels CuCr 2 S 4 and CuCo 2 S 4 have been prepared and examined by x-ray diffraction. In each case the spinel pattern was accompanied by a number of weak foreign reflections consistent with the presence of a single impurity phase, identified as γ-CuCrS 2- x and CoS 2 respectively. Careful str…
SummaryElectron microscopy of carbon replicas taken from outer surfaces, sections and cell base patterns of anodic films, formed in oxalic acid, has enabled relationships between the main film parameters of barrier layer thickness, cell size and pore diameter to be quantified and related to the anodizing variables. In…
The potential-pH-temperature relationships for the aluminium-water system have been calculated by the methods of de Bethune, Khodakovskiy, Criss and Cobble, and Helgeson and a critical comparison made. The Criss and Cobble method produced the most consistent results and was used to construct a corrosion diagram for th…
The structure of Na2W4O13 has been determined by Patterson and Fourier methods from 426 independent reflections measured photographically. The basic units, consisting of four edge-shared octahedra, are linked along two crystallographic directions by corner sharing to form octahedral layers, which are held together by…