Economic laws of division and changing the labor in the system of contemporary vocational education determination

The topical character of the problem in question is stipulated by the demand of highly skilled competitive personnel in the vocational education sphere of modern society, which is determined by the totality of objective and subjective factors of its development. The goal of the present research consists in the verification of the economic laws of division and change of the labor, that produce an immediate impact on the vocational education development strategy and a mediated impact on the requirements made to the personality of a student within this system. The primary method of investigation in the given area is the modelling method that allows to identify specific features of these laws’ operation depending on the historical period of social development and extrapolate their functioning on the present-day reality as well as make scientifically-based forecasts of its future development. Research outcomes: the article presents a structural functional model of the interaction of the economic laws of division and changing the labor during the industrial and post-industrial periods of social development; an algorithm of competently mature personality’s character formation in the modern system of vocational education. Materials of the research may prove useful to the rule-making specialists and practitioners in the educational sphere – in elaborating and upgrading educational and professional standards, in developing a model for the preparation of future competitive workers in the system of vocational education based on the objective factors of its development, such as the economic laws of division and change of the labor. © 2016 Ronzhina et al

Shape parameters of Galactic open clusters

(abridged) In this paper we derive observed and modelled shape parameters (apparent ellipticity and orientation of the ellipse) of 650 Galactic open clusters identified in the ASCC-2.5 catalogue. We provide the observed shape parameters of Galactic open clusters, computed with the help of a multi-component analysis. For the vast majority of clusters these parameters are determined for the first time. High resolution ("star by star") N-body simulations are carried out with the specially developed $\phi$GRAPE code providing models of clusters of different initial masses, Galactocentric distances and rotation velocities. The comparison of models and observations of about 150 clusters reveals ellipticities of observed clusters which are too low (0.2 vs. 0.3), and offers the basis to find the main reason for this discrepancy. The models predict that after $\approx 50$ Myr clusters reach an oblate shape with an axes ratio of $1.65:1.35:1$, and with the major axis tilted by an angle of $q_{XY} \approx 30^\circ$ with respect to the Galactocentric radius due to differential rotation of the Galaxy. Unbiased estimates of cluster shape parameters require reliable membership determination in large cluster areas up to 2-3 tidal radii where the density of cluster stars is considerably lower than the background. Although dynamically bound stars outside the tidal radius contribute insignificantly to the cluster mass, their distribution is essential for a correct determination of cluster shape parameters. In contrast, a restricted mass range of cluster stars does not play such a dramatic role, though deep surveys allow to identify more cluster members and, therefore, to increase the accuracy of the observed shape parameters.Comment: 13 pages, 12 figures, accepted for publication in Astronomy and Astrophysic

Explosion of heterogeneous water droplet in a high-temperature gaseous region

Using high-speed video recording tools (up to 10{5} frames per second) and "TEMA Automotive" and "Phantom Camera Control" software packages the experimental features of explosive disintegration, boiling and evaporation of water droplets with comparably sized solid inclusions heated in high-temperature (more than 650 K) gaseous region were determined. The necessary and sufficient conditions of explosive vapor formation achievement with the next heterogeneous water droplet disintegration were found

The search for magnetic fields in mercury-manganese stars

We performed a highly sensitive search for magnetic fields on a large set of HgMn stars. With the aid of a new polarimeter attached to the HARPS spectrometer at the ESO 3.6m-telescope, we obtained high-quality circular polarization spectra of 41 single and double HgMn stars. Using a multi-line analysis technique on each star, we co-added information from hundreds of spectral lines resulting in significantly greater sensitivity to the presence of magnetic fields, including very weak fields. For the 47 individual objects studied, including 6 components of SB2 systems, we do not detect any magnetic fields at greater than the 3 sigma level. The lack of detection in the circular polarization profiles indicates that if strong fields are present on these stars, they must have complex surface topologies. For simple global fields, our detection limits imply upper limits to the fields present of 2-10 Gauss in the best cases. We conclude that HgMn stars lack large-scale magnetic fields, typical for spotted magnetic Ap stars, sufficient to form and sustain the chemical spots observed on HgMn stars. Our study confirms that in addition to magnetically altered atomic diffusion, there exists another differentiation mechanism operating in the atmospheres of late-B main sequence stars which can compositional inhomogeneities on their surfaces.Comment: 12 pages, 8 figures, 2 table

Chemical spots in the absence of magnetic field in the binary HgMn star 66 Eridani

According to our current understanding, a subclass of the upper main sequence chemically peculiar stars, called mercury-manganese (HgMn), is non-magnetic. Nevertheless, chemical inhomogeneities were recently discovered on their surfaces. At the same time, no global magnetic fields stronger than 1-100 G are detected by modern studies. The goals of our study are to search for magnetic field in the HgMn binary system 66 Eri and to investigate chemical spots on the stellar surfaces of both components. Our analysis is based on high quality spectropolarimetric time-series observations obtained during 10 consecutive nights with the HARPSpol instrument at the ESO 3.6-m telescope. To increase the sensitivity of the magnetic field search we employed a least-squares deconvolution (LSD). We used spectral disentangling to measure radial velocities and study line profile variability. Chemical spot geometry was reconstructed using multi-line Doppler imaging. We report a non-detection of magnetic field in 66 Eri, with error bars 10-24 G for the longitudinal field. Circular polarization profiles also do not indicate any signatures of complex surface magnetic fields. For a simple dipolar field configuration we estimated an upper limit of the polar field strength to be 60-70 G. For the HgMn component we found variability in spectral lines of Ti, Ba, Y, and Sr with the rotational period equal to the orbital one. The surface maps of these elements reconstructed with the Doppler imaging technique, show relative underabundance on the hemisphere facing the secondary component. The contrast of chemical inhomogeneities ranges from 0.4 for Ti to 0.8 for Ba.Comment: 13 pages, 14 figure

Three-dimensional magnetic and abundance mapping of the cool Ap star HD 24712 I. Spectropolarimetric observations in all four Stokes parameters

High-resolution spectropolarimetric observations provide simultaneous information about stellar magnetic field topologies and three-dimensional distributions of chemical elements. Here we present analysis of a unique full Stokes vector spectropolarimetric data set, acquired for the cool magnetic Ap star HD 24712. The goal of our work is to examine circular and linear polarization signatures inside spectral lines and to study variation of the stellar spectrum and magnetic observables as a function of rotational phase. HD 24712 was observed with the HARPSpol instrument at the 3.6-m ESO telescope over a period of 2010-2011. The resulting spectra have S/N ratio of 300-600 and resolving power exceeding 100000. The multiline technique of least-squares deconvolution (LSD) was applied to combine information from the spectral lines of Fe-peak and rare-earth elements. We used the HARPSPol spectra of HD 24712 to study the morphology of the Stokes profile shapes in individual spectral lines and in LSD Stokes profiles corresponding to different line masks. From the LSD Stokes V profiles we measured the longitudinal component of the magnetic field, , with an accuracy of 5-10 G. We also determined the net linear polarization from the LSD Stokes Q and U profiles. We determined an improved rotational period of the star, P_rot = 12.45812 +/- 0.00019d. We measured from the cores of Halpha and Hbeta lines. The analysis of measurements showed no evidence for a significant radial magnetic field gradient in the atmosphere of HD 24712. We used our and net linear polarization measurements to determine parameters of the dipolar magnetic field topology. We found that magnetic observables can be reasonably well reproduced by the dipolar model. We discovered rotational modulation of the Halpha core and related it a non-uniform surface distribution of rare-earth elements.Comment: Accepted for publication in A&

Magnetism, chemical spots, and stratification in the HgMn star phi Phoenicis

Mercury-manganese (HgMn) stars have been considered as non-magnetic and non-variable chemically peculiar (CP) stars for a long time. However, recent discoveries of the variability in spectral line profiles have suggested an inhomogeneous surface distribution of chemical elements in some HgMn stars. From the studies of other CP stars it is known that magnetic field plays a key role in the formation of surface spots. All attempts to find magnetic fields in HgMn stars have yielded negative results. In this study, we investigate the possible presence of a magnetic field in phi Phe (HD 11753) and reconstruct surface distribution of chemical elements that show variability in spectral lines.We also test a hypothesis that a magnetic field is concentrated in chemical spots and look into the possibility that some chemical elements are stratified with depth in the stellar atmosphere. Our analysis is based on high-quality spectropolarimetric time-series observations, covering a full rotational period of the star. Spectra were obtained with the HARPSpol at the ESO 3.6-m telescope. Combining information from all suitable spectral lines, we set an upper limit of 4 G on the mean longitudinal magnetic field. For chemical spots, an upper limit on the longitudinal field varies between 8 and 15 G. We confirmed the variability of Y, Sr, and Ti and detected variability in Cr lines. Stratification analysis showed that Y and Ti are not concentrated in the uppermost atmospheric layers. Our spectropolarimetric observations rule out the presence of a strong, globally-organised magnetic field in phi Phe. This implies an alternative mechanism of spot formation, which could be related to a non-equilibrium atomic diffusion. However, the typical time scales of the variation in stratification predicted by the recent time-dependent diffusion models exceed significantly the spot evolution time-scale reported for phi Phe.Comment: Accepted for publication in Astronomy & Astrophysics, 15 pages, 15 figure

Galactic Rotation Parameters from Data on Open Star Clusters

Currently available data on the field of velocities Vr, Vl, Vb for open star clusters are used to perform a kinematic analysis of various samples that differ by heliocentric distance, age, and membership in individual structures (the Orion, Carina--Sagittarius, and Perseus arms). Based on 375 clusters located within 5 kpc of the Sun with ages up to 1 Gyr, we have determined the Galactic rotation parameters Wo =-26.0+-0.3 km/s/kpc, W'o = 4.18+-0.17 km/s/kpc^2, W''o=-0.45+-0.06 km/s/kpc^3, the system contraction parameter K = -2.4+-0.1 km/s/kpc, and the parameters of the kinematic center Ro =7.4+-0.3 kpc and lo = 0+-1 degrees. The Galactocentric distance Ro in the model used has been found to depend significantly on the sample age. Thus, for example, it is 9.5+-0.7 kpc and 5.6+-0.3 kpc for the samples of young (50 Myr) clusters, respectively. Our study of the kinematics of young open star clusters in various spiral arms has shown that the kinematic parameters are similar to the parameters obtained from the entire sample for the Carina-Sagittarius and Perseus arms and differ significantly from them for the Orion arm. The contraction effect is shown to be typical of star clusters with various ages. It is most pronounced for clusters with a mean age of 100 Myr, with the contraction velocity being Kr = -4.3+-1.0 km/s.Comment: 14 pages, 4 figures, 2 table

The Near-Infrared and Optical Spectra of Methane Dwarfs and Brown Dwarfs

We identify the pressure--broadened red wings of the saturated potassium resonance lines at 7700 \AA as the source of anomalous absorption seen in the near-infrared spectra of Gliese 229B and, by extension, of methane dwarfs in general. This conclusion is supported by the recent work of Tsuji {\it et al.} 1999, though unlike them we find that dust need not be invoked to explain the spectra of methane dwarfs shortward of 1 micron. We find that a combination of enhanced alkali abundances due to rainout and a more realistic non-Lorentzian theory of resonant line shapes may be all that is needed to properly account for these spectra from 0.5 to 1.0 microns. The WFPC2 $I$ measurement of Gliese 229B is also consistent with this theory. Furthermore, a combination of the blue wings of this K I resonance doublet, the red wings of the Na D lines at 5890 \AA, and, perhaps, the Li I line at 6708 \AA can explain in a natural way the observed WFPC2 $R$ band flux of Gliese 229B. Hence, we conclude that the neutral alkali metals play a central role in the near-infrared and optical spectra of methane dwarfs and that their lines have the potential to provide crucial diagnostics of brown dwarfs. We speculate on the systematics of the near-infrared and optical spectra of methane dwarfs, for a given mass and composition, that stems from the progressive burial with decreasing \teff of the alkali metal atoms to larger pressures and depths.Comment: Revised and accepted to Ap.J. volume 531, March 1, 2000, also available at http://jupiter.as.arizona.edu/~burrows/papers/BMS.p