No abstract available

[en] Ionic species in deuterium plasma have been analysed using a quadrupole mass spectrometer. The mass spectrometer possessed adequate resolution and sensitivity for species in the mass range from 2 to 45. The intensity of the ion current collected at the mass spectrometer showed a strong dependence on the plasma gas pressure. In the higher pressure region of about 5 Ps the ionic species showed a tendency to shift to the larger molecules of D₃⁺ and D₃O⁺ from D₂⁺. Measurements were also made to characterize the conditions of the plasma states studied and information is given on electron density and temperature, the plasma potential and the related light emission. (author)

[en] A striking correlation has been found to exist between the ionic charge and dielectric constants of A^IB^IIIC₂^VI and A^IIB^IVC₂^V chalcopyrite semiconductors. The dielectric constants of these compounds exhibit a linear relationship when plotted on a log-log scale against the nearest neighbour distance d (A), but fall on different straight lines according to the product of ionic charges of the compounds. A fairly good agreement has been found between the observed and calculated values of the dielectric constants for A^IB^IIIC₂^VI and A^IIB^IVC₂^V semiconductors

[en] Gyromagnetic frequencies, multiples of the fundamental frequency, have been identified on the ionograms recorded on the ground; the real height where reflexions take place have been found. (author)

[en] A small number of interplanetary coronal mass ejections (ICMEs) have been identified that contain measurable contributions from prominence plasma. In situ measurements from during these events are marked by the presence of unusually low-charge states of C, O, and Fe, representing ionization equilibrium formation temperatures of ∼10⁴–10⁵ K, consistent with prominence material observed at the Sun. We present a thorough analysis of the elemental abundances of a wide variety of heavy ions, measured by Advanced Composition Explorer/SWICS, in prominence material observed in the solar wind. We find that prominence material observed in situ tends to be more enriched in heavy ions than the surrounding ICME plasma and the fast and slow solar wind. We also find that the material is on average moderately enhanced in low first ionization potential elements compared to photospheric abundances, with values that lie between fast and slow solar wind. In rare instances, where in situ prominence material is observed to have clear, persistent, low-charge states over longer periods of time, it exhibits elemental abundances that are photospheric in nature. However, in most prominence events we see indications that the associated material contains a mixture of prominence and adjacent ICME plasma. The anomalous behavior of the elemental and ionic composition in ICMEs with and without prominence material can be used to study physical processes that occur during CME initiation and release.

[en] The effect of the plasma chemical composition on the development of the Farley-Buneman instability has been analyzed. The consideration is made numerically, in hydrodynamic approximation, for a plasma with polar ionosphere E-layer parameters. The results obtained show that additions of heavy ions in amounts, quite characteristic of the ionosphere E-layer, can affect the parameters being measured of the processes, determined by the Farley-Buneman instability, to the same extent as changes in a large-scale electric field at the ionospheric heights do, which must be taken into account for interpreting experimental data

[en] Changes due to the initial oxidation of Al(001) were determined from results of the first self-consistent thin-film calculations for the clean Al(001) surface as well as Al(001)-p(1 x 1)O. For clean Al(001), surface state-surface resonance bands obtained for a nine-layer slab were found to be in good agreement with photoemission measurements and our earlier non-self-consistent results; its work function (4.7 +- 0.1 eV) is in good agreement with the Grepstad et al. experimental value (4.41 +- 0.03 eV); no surface core-level shift was found in agreement with a recent photoemission measurement; finally, the absence of an increased broadening in the surface Al(2p) core level is discussed. For the nine-layer Al(001) plus O slab, the calculated reduction in the work function (0.6 eV) is in good agreement with the experimentally determined reduction (0.5--0.8 eV). Prominent O(2p) peaks in the surface layer density of states at -8.0 and -10.0 eV below E/sub F/ are in good agreement with photoemission measurements. Structure at 1.0 and 1.8 eV above E/sub F/, due to O-induced surface resonance states, are related to interface states observed by surface soft-x-ray absorption spectroscopy. The overall bonding is found to be ionic in character with charge transfer onto the O atoms. A surface core-level shift of 1.5 eV to greater binding energy is found for the surface Al atom, in excellent agreement with the Eberhardt and Kunz 1.4-eV Al(2p) shift. It is concluded that in the initial stages of oxidation a substantial number of O atoms are chemisorbed into coplanar, fourfold hollow sites, which is consistent with a recent extended-appearance-potential-fine-structure measurement for the Al--O bond length and an earlier self-consistent cluster calculation

[en] The bulk resistance of some superionic solids has been obtained via the Lissajous method and impedance spectroscopy technique. As a means to distinguish which method is more reliable, the impedance of a single parallel R-C circuit was measured by the two methods and the experimental data were compared with simulated data. Comparison of bulk resistance obtained by using different instruments with a narrow and a wide frequency range is also briefly discussed

[en] The effect of the additive non ionic polyacrylamide (PAM), was studied at the laboratory level, as refining crystalline grain in the copper electrorefining. Experiments were performed 24 h of electrolysis, using an electrolyte of copper sulphate acid, with 0.5 to 10 mg^-1 polyacrylamide at 55 degree centigrade and a current density of 260 Am^-2. The effectiveness of these organic additives in copper electrorefining was determined by directly measuring the surface roughness of the copper deposit and contrasted with the results of other instrumental techniques (SEM and metallographic analysis). The results of the analysis SEM, metallographic analysis and measurement of the surface roughness of the copper deposit, show that to concentrations as low as 0.5 mg^-1 of this additive is manifested its property of tuner of grain. However, in the range of 7 to 10 mg^-1 of polyacrylamide, it reaches an optimum size of grain for the deposit of copper in the cathodes. (Author)

No abstract available