Chemo-dynamical evolution of Globular Cluster Systems

We studied the relation between the ratio of rotational velocity to velocity dispersion and the metallicity (/\sigma_{v}-metallicity relation) of globular cluster systems (GCS) of disk galaxies by comparing the relation predicted from simple chemo-dynamical models for the formation and evolution of disk galaxies with the observed kinematical and chemical properties of their GCSs. We conclude that proto disk galaxies underwent a slow initial collapse that was followed by a rapid contraction and derive that the ratio of the initial collapse time scale to the active star formation time scale is \sim 6 for our Galaxy and \sim 15 for M31. The fundamental formation process of disk galaxies was simulated based on simple chemo-dynamical models assuming the conservation of their angular momentum. We suggest that there is a typical universal pattern in the /\sigma_{v}-metallicity relation of the GCS of disk galaxies. This picture is supported by the observed properties of GCSs in the Galaxy and in M31. This relation would deviate from the universal pattern, however, if large-scale merging events took major role in chemo-dynamical evolution of galaxies and will reflect the epoch of such merging events. We discuss the properties of the GCS of M81 and suggest the presence of past major merging event.Comment: 25 pages, 8 figures, Accepted for publication in the Astrophysical Journa

L'aspect verbal dans les langues slaves

Maline M. L'aspect verbal dans les langues slaves. In: Revue belge de philologie et d'histoire, tome 36, fasc. 3, 1958. Langues et littératures modernes — Moderne talen en letterkunden. pp. 873-875

Distribution of Zooplankton in Harlan County Reservoir, Nebraska

The objective of this study was to determine the horizontal and vertical distribution of zooplankton in Harlan County Reservoir in order to assist in developing an appropriate zooplankton sampling regime for this and similar Nebraska irrigation reservoirs. Samples were collected at 16 sites distributed across 3 zones of the reservoir monthly in April, May, June, and July of 2007 using a 2.2 L Van Dorn sampler. Samples were collected at depths of 1, 4, and 7 meters, poured through an 80-μm filter, preserved, and identified to the lowest possible taxa. Total zooplankton densities in Harlan County Reservoir were statistically similar for samples collected at 1 m, 4 m, and 7 m of depth from April, June, and July samples. Samples collected in May had significantly more zooplankton at 1 m of depth (F = 6.98; p ≤ 0.01) compared to 4 m and 7 m. Density of total zooplankton collected at 1 m depth from pelagic and littoral sites in zone 1 was similar among months. Also, zooplankton densities were similar from the upper, middle, and lower regions of Harlan County Reservoir in all four sample months. These results indicate that zooplankton distribution in Harlan County Reservoir have a homogeneous vertical and horizontal distribution

SiC-TiSi2 materials codeposited by CVD

Abstract SiC - TiSi2 composites were prepared by CVD under atmospheric pressure at 850°C using the TiCl4 - SiH2Cl2 - C4H10 - H2 gas system. Thermodynamical calculation trends, dealing with the influence of the initial gas phase composition on the amount of TiSi2 were compared with the experiments. Codeposits were texture-free. Apparent crystallite size was ranging between 20 to 50nm. Intrinsic hardness deduced from the extrapolation at infinite load of measured values, fitted well with that given by a rule mixture : H∞=VTiSi2.HTiSi2+(l-VTiSi2).HSiC. Using indentation technique, median-radial crack system was observed. Values of toughness were about 35 to 50 % greater than for a pure SiC-CVD depending on the amount of TiSi2

Auger electron spectroscopy of compounds in the Si-Ti-C system : characterization of Si-Ti-C multiphased materials obtained by CVD

Auger peak-position and line-shape analyses of the Si LVV, Si KLL, C KVV, and Ti LMM transitions for the ref. compds. Ti, Si, SiC, TiC, TiC0.72, TiSi2, Ti5Si3(C), and Ti3SiC2, belonging to the ternary Si-Ti-C system have been performed. The results show that there are sufficient differences in Auger peak positions and line shapes to allow identification of the compds. The Auger line shapes of the C KVV transitions for Ti3SiC2 and Ti0.57Si0.33C0.1 (C solid soln. in Ti5Si3) were found to be characteristic of C bonded to Ti. The Ti L3M23M45 transition was found to be very sensitive to changes in the nature of the compds. The spectra recorded for the ref. compds. were used to characterize Si-Ti-C multiphased materials obtained by CVD. SiC-X (X = TiSi2, Ti3SiC2, or TiC + C) mixts. were identified. [on SciFinder (R)

Auger electron spectroscopy of compounds in the Si-Ti-C system : characterization of Si-Ti-C multiphased materials obtained by CVD

Auger peak-position and line-shape analyses of the Si LVV, Si KLL, C KVV, and Ti LMM transitions for the ref. compds. Ti, Si, SiC, TiC, TiC0.72, TiSi2, Ti5Si3(C), and Ti3SiC2, belonging to the ternary Si-Ti-C system have been performed. The results show that there are sufficient differences in Auger peak positions and line shapes to allow identification of the compds. The Auger line shapes of the C KVV transitions for Ti3SiC2 and Ti0.57Si0.33C0.1 (C solid soln. in Ti5Si3) were found to be characteristic of C bonded to Ti. The Ti L3M23M45 transition was found to be very sensitive to changes in the nature of the compds. The spectra recorded for the ref. compds. were used to characterize Si-Ti-C multiphased materials obtained by CVD. SiC-X (X = TiSi2, Ti3SiC2, or TiC + C) mixts. were identified. [on SciFinder (R)