Materials Literature
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Binary mixtures of calcium nitrate with potassium nitrate can be supercooled extensively below their normal solidus temperatures. Comparable binary mixtures have now been studied with sodium, rubidium or caesium as the monovalent cation. Viscosities are in the sequence Na>Cs>Rb>K at high temperatures. On progressive c…
Abstract The isolation, characterisation and chemical investigation of the cardiac glycosides of the dried leaves of Isoplexis isabelliana (W EBB ) M ASF . are described. 7 glucosides B, D, E, J (monoside), K, M, and 1 (monoside) could be obtained in homogenous form, 3 others were mixtures (“A” = A 1 + A 2 , “C” = C 1…
Abstract Mössbauer investigations are reported for five different compositions of gallium iron oxide and for iron‐substitutedβ‐Ga 2 O 3 , and AlFeO 3 . The spectra confirm the ferrimagnetic spin‐arrangement of Ga 2−x Fe x O 3 . Information is obtained on the cation distribution in iron‐substituted (β‐Ga 2 O 3 and Ga 2…
The macroscopic strength of an oriented medium is investigated under the assumption that processes of breaking and reforming of microscopic components in the medium may occur. The differential equation governing the time-dependent variation of the number of load-carrying components is considered. Emphasis is placed on…
This paper reviews methods which have been used to elucidate the quantity Dq in cubic and non-cubic molecules. A novel graphical method allowing the rapid determination of Dq and B from spin-allowed absorption bands of high-spin d 2, d 3, d 7, and d 8 complexes is introduced. It is possible to calculate both in-plane…
A critical evaluation is made of the procedure and the important parameters involved in estimating the stacking-fault energy Γ from x-ray diffraction measurements of deformed materials. The published data for the Ag-In and the Cu-Zn system are carefully analyzed and compared with results obtained by transmission elect…
The effects of stress concentration on the nucleation of deformation twins have been investigated in zinc bicrystals grown with controlled orientations. It is found that the apparent resolved shear stress for twinning varies from 25 to 4900 g/mm2 depending upon the orientations of the individual crystal grains of the…
Radio-frequency sputtering cannot be used for absolute measurements of sputtering yields because of the spread in energies of the bombarding ions. This paper describes how these yields can be studied by simultaneously sputtering with the insulators other materials with known dc sputtering yields. Silicon and germanium…
The adsorption and the reaction rate were studied during the course of the decomposition of formic acid on alumina and silica catalysts and the types of chemisorbed species, their surface concentrations and also the partial pressures of each gases were determined. Accordingly, the dependence of the overall rate upon t…
The five-ball fatigue tester and full-scale rolling-element bearings were used to determine the effect of component hardness differences of SAE 52100 steel on bearing fatigue and load capacity. Maximum fatigue life and load capacity are achieved when the rolling elements of a bearing are one to two points (Rockwell C)…
Abstract The behaviour of single crystal specimens of MgZn 2 deformed by basal slip is investigated by both dynamic and creep tests at temperatures between 250 and 500 °C. With the dynamic experiments a smooth upper yield point is observed. The temperature dependence of the critical resolved shear stress and of the se…
Activation of rare‐earth oxides by ions other than rare earths is successfully attempted in the present investigation. Bi +3 is incorporated in yttrium, gadolinium, and lanthanum oxides by solid state reaction. Probably a chargetransfer mechanism involving bismuth and oxygen introduces an absorption band at about 3200…
The decomposition into nitrogen and hydrogen on heated filaments was studied at pressures of 10–4 torr and less with both conventional and ultra-high vacuum (u.h.v.) techniques. The reaction probability P of an ammonia molecule at a collision with the platinum was determined under various conditions. Particular attent…
Peer Reviewed
Defects in single crystals of solution-grown surcrose have been studied using optical and electron microscopy. From an examination of the etch figures (produced by aqueous ethanol) and the cleavage patterns on {100} faces it is shown that dislocations may move on the {h10} planes in the 〈001〉 directions and on the {h0…
In the tail part region of the first exciton band, the absorption constant (10 -1 to 10 2 cm -1 ) was measured on zone-refined and Harshaw NaCl single crystals from 10°K to 573°K. Fundamental absorption tails of pure NaCl single crystals are represented by the modified Urbach rule, which describes the influence of zer…
Abstract Dilatométric studies on five PMM samples of different tacticities show generally three transition ranges between −35 and 150°C. The main glass transition temperature depends on the relative proportion of the iso‐ or syndiotactic segments. The secondary transition, located around 60°C., seems to be related to…
Abstract A 12×12 representation is given of the valence band Hamiltonian at k = 0 which includes the spin‐orbit interaction. Expressions are derived for the energies and the linear combinations of the wave functions for the Γ 7 , Γ 8 , and Γ 9 subbands. The whole valence band is completely determined by eight paramete…
The addition of tributyltin methoxide and of biotributyltin oxide to the following acceptor molecules is described : isothiocyanates, trichloroacetonitrile, carbon disulphide, carbon dioxide, sulphur dioxide, and carbodi-imides. The corresponding phenoxide is generally less reactive than the methoxide. The initial pro…
The oligomerization of substituted phenyl glycidyl ethers was studied kinetically in the presence of dimethylbenzylamine using toluene or dioxane as a solvent. The infrared spectra of the resultant oligomers suggest that the reaction products have the internal carbon-carbon double-bond un-saturation, which is confirme…