Erosion of solid D2 by 2 keV electrons

The erosion/sputtering of D₂ films on an Au-substrate by 2 keV electrons is roughly inversely proportional to film thicknesses below ≈650 Å. The erosion yield decreases from 200 atoms/electron at 25 Å to 7.8 ± 0.5 for “bulk” targets. The thickness dependent region is apparently unrelated to the penetration depth of the electrons.     

Design and use of an electronic speckle pattern interferometer for testing of turbine parts

The construction and use of an electronic speckle pattern interferometer for vibration testing of critical gas turbine parts in the factory, is described.     

Retro carotenoids with substituted 2,5-oxa-bicycloheptane end groups

BF₃-mediated formation of a 2,5-oxygen bridge from carotenoids with 2-hydroxy-β-type end groups accompanied by dehydrogenation and $\text{retro}$ shift of the polyene system is reported. The configuration of the Δ6,6′ double bonds are established by ¹H NMR.     

Alkyl chain order in a lamellar lyotropic liquid crystal with varying surface charge density

The alkyl chain order in the lamellar liquid-crystalline phase formed in the octylamine/octylammonium chloride/water system has been investigated by ²H N.M.R. at constant mole ratio water/amphiphile and varying charge of the lamellae. The results are correlated to the dimensions of the aggregate obtained from X-ray low angle diffraction measurements.     

Electronic structure of H and He in metal vacancies

The electronic structure of H and He impurities in metals is calculated using the Gunnarsson-Hjelmberg method of solving the Kohn-Sham equation. The jellium model is used for the metal. The differences between interstitial and substitutional impurity sites are emphasized. For normal metallic densities it is found that both impurities favour sites of lower than average conduction electron density because here the impurity electrons can relax to a situation of lower kinetic energy.     

Tentatively identified and predicted H- Fano resonances

Positions are calculated for the Fano resonances that are due to interactions of the discrete autoionized 1s3s, 1s3p, and 1s4p states of H^- with overlapping split-configuration continua. The two first-mentioned resonances are tentatively identified with the diffuse interstellar doublets at λλ6376,6379 and λλ5780, 5797 on the basis of the relative positions of the autoionized states and the relative intensities of the doublet components.The observed wave-numbers of the 1s2s, 1s3s, 1s2p, and 1s3p resonances seem to belong to two series that converge towards a common limit in a kind of reverse Rydberg-series fashion. The position of the limit is close to 9000 Å, in accordance with theory. An extrapolation leads to the identification of the 1s4p resonance with the diffuse λ 6614 line. A further extrapolation leads to the prediction of positions at about 7183 and 7583 Å for the 1s5p and 1s6p resonances.The half-widths calculated for the singlet components of the 1s3p and 1s4p resonances are of the order of magnetude of those observed for the diffuse lines, and of the observed distance between the probably partly mixed singlet and triplet 1s3p components. The profile of the λ 5780 resonance is calculated on the basis of an assumed helium-line value for the oscillator strength. Its shape indicates that the “λ 5778 band” may be just a misinterpretation of the asymmetric wings.Tables of Hartree functions for the 3s², 3p² and 4p² configurations of H^- are given in an appendix.     

Reaction amplitude for n-mesons a generalization of the Veneziano-Bardakçi-Ruegg-Virasoro model

The Veneziano model for the binary meson reaction (n = 4), generalized by Bardakçi and Ruegg and by Virasoro to n = 5, is further extended to the case of arbitrary n. The multi-resonance structure of the n-meson reaction is analyzed with the help of “quark diagrams”. An integral representation for the reaction amplitude, its basic properties (recurrence formulae, multi-poles and multi-Reggeization) are presented. A consistent normalization leads to certain relations between coupling constants and trajectory slopes.     

Properties of nasicon electrolytes prepared from alkoxide derived gels: Ionic conductivity,durability in molten sodium and strength test data

Nasicon ceramics have been prepared from gel-derived raw materials both by conventional sintering and by hot-pressing. For several compositions the ionic conductivity have been determined by the AC-method. The properties of ceramics based on the ZrO₂-poor composition Na_2.94Zr_1.49P_0.8Si_2.2O_10.85 have been studied in greater detail. Durability test in Na/Na-cells so far indicate good stability at 300°C, and corrosion tests in molten sodium (400°–700°C) indicate that at 400°, 350° and 300°C it will take respectively at least 100 h, 7 weeks and 3 years to dissolve a 1 micron thich layer of the ceramic. The fracture strenght of the ceramics have been determined by the three point bending method. Weibul statistics indicate an average fracture strength of 168 MPa and a m-value of 8.3 (sample vol. 0.07 cm³) for the best ceramics prepared so far.