Peculiarities and variations in the optical spectrum of the post-AGB star V448Lac=IRAS22223+4327

Repeated observations with high spectral resolution acquired in 1998-2008 are used to study the temporal behavior of the spectral line profiles and velocity field in the atmosphere and circumstellar envelope of the post-AGB star V448Lac. Asymmetry of the profiles of the strongest absorption lines with low-level excitation potentials less 1eV and time variations of these profiles have been detected, most prominently the profiles of the resonance lines of BaII, YII, LaII, SiII. The peculiarity of these profiles can be explained using a superposition of stellar absorption line and shell emission lines. Emission in the (0;1) 5635A Swan band of the C2 molecule has been detected in the spectrum of V448Lac for the first time. The core of the Halpha line displays radial velocity variations with an amplitude ~8 km/s. Radial velocity variations displayed by weakest metallic lines with lower amplitudes, 1-2 km/s, may be due to atmospheric pulsations. Differential line shifts, 0 -- 8 km/s, have been detected on various dates. The position of the molecular spectrum is stationary in time, indicating a constant expansion velocity of the circumstellar shell, Vexp=15.2 km/s, as derived from the C2 and NaI lines.Comment: 19 pages, 8 figures, 1 tabl

Evolutionary stage of the spectral variable BD+48 1220=IRAS 05040+4820

Based on high-resolution observations (R=60000 and 75000), we have studied the optical spectral variability of the star BD+48 1220 (IRAS05040+4820). We have measured the equivalent widths of numerous absorption lines of neutral atoms and ions at wavelengths from 4500 to 6760 AA, as well as the corresponding radial velocities. We use model atmospheres to determine Teff=7900K, log g=0.0, microturbulence velocity xi_t=6.0, and the abundances for 16 elements. The star's metallicity differs little from the solar value: [Fe/H]=-0.10 dex. The main peculiarity of the chemical composition of the star is a large He-excess, derived from the HeI 5876 A absorption, [He/H]=+1.04, and the equally large O-excess, [O/Fe]=+0.72 dex. The C-excess is small, [C/Fe]=+0.09 dex, and the ratio [C/O]$\le$ 1. We obtained a revised relation for the light-metal abundances: [Na/Fe]=+0.87 with [Mg/Fe]=-0.31. The barium abundance is low, [Ba/Fe]=-0.84. The radial velocity of the star measured from photospheric absorption lines over three years of observations varies in the interval V_sun = -(7 - 15) km/s. Time variable differential line shifts have been revealed. The entire set of available data (the luminosity Mv~-5m, velocity V_lsr~-20 km/s, metallicity [Fe/H]=-0.10, and peculiarities of the optical spectrum and chemical composition) confirms the status of BD+48 1220 as a post-AGB star with He- and O-excesses belonging to the Galactic disk.Comment: 42 pages, 7 figures, 6 tables, accepted by Astronomy Report

The evolutionary status of the semiregular variable QYSge

Repeated spectroscopic observations made with the 6m telescope of yielded new data on the radial-velocity variability of the anomalous yellow supergiant QYSge. The strongest and most peculiar feature in its spectrum is the complex profile of NaI D lines, which contains a narrow and a very wide emission components. The wide emission component can be seen to extend from -170 to +120 km/s, and at its central part it is cut by an absorption feature, which, in turn, is split into two subcomponents by a narrow (16km/s at r=2.5) emission peak. An analysis of all the Vr values leads us to adopt for the star a systemic velocity of Vr=-21.1 km/s, which corresponds to the position of the narrow emission component of NaI. The locations of emission-line features of NaI D lines are invariable, which point to their formation in regions that are external to the supergiant's photosphere. Differential line shifts of about 10km/s are revealed. The absorption lines in the spectrum of QYSge have a substantial width of FWHM~45 km/s. The method of model atmospheres is used to determine the following parameters: Teff=6250K, lg g=2.0, and microturbulence Vt=4.5km/s. The metallicity of the star is found to be somewhat higher than the solar one with an average overabundance of iron-peak elements of [Met/H]=+0.20. The star is found to be slightly overabundant in carbon and nitrogen, [C/Fe]=+0.25, [N/Fe]=+0.27. The alpha-process elements Mg, Si, and Ca are slightly overabundant [alpha/H]=+0.12. The strong sodium excess, [Na/Fe]=+0.75, is likely to be due to the dredge-up of the matter processed in the NeNa cycle. Heavy elements of the s-process are underabundant relative to the Sun. On the whole, the observed properties of QYSge do not give grounds for including this star into the group of RCrB or RVTau-type type objects.Comment: 29 pages, 8 figures, 4 tables; accepted by Astrophys. Bulleti

Shibusawa Eiichi\u27s View of Japan\u27s Foreign Affairs: Focusing on His Influences on the Meiji Government

From the mid-nineteenth century, Asia, including China and Japan, has been involved in the trend of modernization that was triggered by the activities of European and American powers in this area. In a time of drastic changes, Shibusawa Eiichi (1840-1931) assumed several roles successively: he served as retainer during the bakumatsu period, as official in the Meiji government, and afterwards as businessman, philanthropist, and non-official diplomat. During his service in the Meiji government from 1869 to 1873 and as an entrepreneur from 1873 to 1909, Shibusawa played a key role in devising economic and diplomatic policies for the Meiji government. He is even considered a major designer of modem Japanese economic systems and society. This paper examines Shibusawa Eiichi\u27s view of Japan\u27s foreign affairs and focuses on the way he influenced the Meiji government

Development of methodology for controlling the parameters of TP

© Published under licence by IOP Publishing Ltd. This article describes TP control step of the intelligent system for predicting the properties of CGI, which includes three parts: the selection of parameters for comparison, the comparison with the simulation results, the change of the current TP. The list of parameters under which control in the production is carried out has been determined, the adjustment algorithm of TP is designed

The effect of the detergent micelles type on the tetrapeptide NAc-SFVG-OMe conformational structure: NMR studies in solution

Process determination of short peptides binding on the cell surface has major implications in better understanding the molecular recognition of cell surfaces. As such methods as on-cell nuclear magnetic resonance (NMR) spectroscopy are very difficult, a large number of membrane mimetic systems such as bilayers, bicelles and detergent micelles use. Micelles are the most frequently used membrane mimetics for the structure determination of peptides and proteins by solution NMR Anionic detergents such as SDS can be more denaturating than the other types, non-ionic micelles being the mildest. Zwitterionic detergent micelles such as DPC are used to mimic eukaryote membranes while the negatively charged SDS micelles would resemble bacterial membranes. Unfortunately, no rules apply when searching for the right detergent. In present paper we studied the effect of the detergent micelles (sodium dodecyl sulfate (SDS) and dodecylphosphocholine (DPC)) on the tetrapeptide SFVG conformational structure. Was shown that the peptide backbone structure is the same in both types of micelles but the sidechain orientation of nonpolar aromatic (Phenylalanine), aliphatic (Glycine) and polar uncharged (Serine) groups are different

Polaris B, an optical companion of Polaris (alpha UMi) system: atmospheric parameters, chemical composition, distance and mass

We present an analysis of high-resolution spectroscopic observations of Polaris B, the optical companion of the Polaris Ab system. The star has a radial velocity V_r of -16.6km/s to -18.9km/s, and a projected rotational velocity vsini=110 km/s. The derived atmospheric parameters are: Teff=6900K; logg=4.3; V_t=2.5km/s. Polaris B has elemental abundances generally similar to those of the Cepheid Polaris A (Usenko et al. 2005a), although carbon, sodium and magnesium are close to the solar values. At a spectral type of F3V Polaris B has a luminosity of 3.868L_sun, an absolute magnitude of +3.30mag, and a distance of 109.5pc. The mass of the star is estimated to be 1.39M_sun, close to a mass of 1.38+/-0.61M_sun for the recently-resolved orbital periods companion Polaris Ab observed by Evans et al. (2007).Comment: 6 pages, 3 figures, 1 tabl

Technology ability of laser bonding of compacted graphite iron

© Published under licence by IOP Publishing Ltd. Laser welding features of compacted graphite iron are described in this paper. An approach that allows to reduce residual stresses and the probability of occurrence of "hot" cracks in the weld seam as well as to increase the absorption coefficient of laser radiation due to the use of metal powder Ni-Cr-B-Si-Fe, BoroTec-Eutalloy® 10009-chromium-nickel alloy are proposed. Recommendations are given when conducting a welding with compacted graphite iron

Testing Rotational Mixing Predictions with New Boron Abundances in Main Sequence B-type Stars

(Abridged) New boron abundances for seven main-sequence B-type stars are determined from HST STIS spectroscopy around the BIII 2066A line. Boron abundances provide a unique and critical test of stellar evolution models that include rotational mixing since boron is destroyed in the surface layers of stars through shallow mixing long before other elements are mixed from the stellar interior through deep mixing. Boron abundances range from 12+log(B/H) = 1.0 to 2.2. The boron abundances are compared to the published values of their stellar nitrogen abundances (all have 12+log(N/H) < 7.8, i.e., they do not show significant CNO-mixing) and to their host cluster ages (4 to 16 Myr) to investigate the predictions from models of massive star evolution with rotational mixing effects (Heger & Langer 2000). Only three stars (out of 34) deviate from the model predictions, including HD36591, HD205021, and HD30836. These three stars suggest that rotational mixing could be more efficient than currently modelled at the highest rotation rates.Comment: 10 figures, 7 tables; accepted for publication in the Astrophysical Journa