Improved distances to several Galactic OB associations

Based on uvbybeta photometry we study the structure of several Galactic star-forming fields. Lac OB1 is a compact association at 520+/-20 pc spatially correlated with a region of intense HII emission in Sh2-126. Loden 112 is a compact OB group at 1630+/-82 pc, probably connected to an extended feature of OB stars located toward the Carina tangent. The field toward Car OB1 is complex and likely contains apparent concentrations representing parts of long segments of the Carina arm projected along the line of sight. Within the classical Mon OB2 association we separate a relatively compact group at 1.26 kpc, that is spatially correlated to the Monoceros Loop SN remnant.Comment: 6 pages, 4 figures, proceedings of "Stellar Clusters and Associations - A RIA workshop on GAIA", 23-27 May 2011, Granada, Spai

Massive Stellar Content of the Galactic Supershell GSH 305+01-24

The distribution of OB stars along with that of H$\alpha$, $^{12}$CO, dust infrared emission, and neutral hydrogen is carried out in order to provide a more complete picture of interactions of the young massive stars and the observed supershell GSH 305+01-24. The studied field is located between $299^\circ \le l \le 311^\circ$ and $-5^\circ \le b \le 7^\circ$. The investigation is based on nearly 700 O-B9 stars with $uvby\beta$ photometry currently available. The derived stellar physical parameters were used to establish a homogeneous scale for the distances and extinction of light for major apparent groups and layers of foreground and background stars in Centaurus and study the interaction with the surrounding interstellar medium. The distance to the entire Centaurus star-forming complex is revised and a maximum of the OB-star distance distribution is found at 1.8$\pm$0.4 (r.m.s) kpc. The massive star component of GSH 305+01-24 is identified at about 85-90 % completeness up to 11.5-12 mag. The projected coincidence of the OB stars with the shell and the similarities between the shell's morphology and the OB-star distribution indicate a strong interaction of the stellar winds with the superbubble material. We demonstrate that these stars contribute a sufficient wind injection energy in order to explain the observed size and expansion velocity of the supershell. The derived stellar ages suggest an age gradient over the Coalsack Loop. A continuous star-formation might be taking place within the shell with the youngest stars located at its periphery and the open cluster NGC 4755 being the oldest. A layer of very young stars at 1 kpc is detected and its connection to both GSH 305+01-24 and the foreground GSH 304-00-12 H I shells is investigated.Comment: Accepted for publication in A&A. Paper consists of 11 pages, 3 tables and 9 figures. Table 1 and Table 3 will only be available from CD

The field of Loden 112

Based on the available uvbybeta photometry of OB stars in the longitude range 281 - 285 deg in the Galactic disk, we identify a feature of young stars at 1630+/-82 pc, that is probably connected to the compact cluster candidate Loden 112 and the open cluster IC 2581. This feature seems to be spatially correlated to RCW 48 and RCW 49 and several other smaller HII regions.Comment: 2 pages, 1 figure, proceedings of "Stellar Clusters and Associations - A RIA workshop on GAIA", 23-27 May 2011, Granada, Spai

Algorithms for Generating Near-Rings on Finite Cyclic Groups

In the present work are described the algorithms that generate all near-rings on finite cyclic groups of order 16 to 29

Thermoelectric Properties of Compacted Micro- and Nanodisperse Graphite Materials

The experimental results of measuring the Seebeck coefficient S for carbon deposits containing multi-walled carbon nanotubes, compacted nanofibers, nano- and ultradisperse amorphous carbon are presented. The value of S for such kind of materials lies in the range of 7 to 60 μV/K. It is indicated that a hopping conduction mechanism is typical of the compacted materials. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3638

Typology of options for metal recycling: Australia’s perspective

While Australia has traditionally relied on obtaining metals from primary sources (namely mined natural resources), there is significant potential to recover metals from end-of-life-products and industrial waste. Although any metals recycling value chain requires a feasible technology at its core, many other non-technical factors are key links in the chain, which can compromise the overall viability to recycle a commodity and/or product. The “Wealth from Waste” Cluster project funded by the Commonwealth Scientific Industrial Research Organisation (CSIRO) Flagship Collaboration Fund and partner universities is focusing on identifying viable options to “mine” metals contained in discarded urban infrastructure, manufactured products and consumer goods. A key aspect of this research is to understand the critical non-technical barriers and system opportunities to enhance rates of metals recycling in Australia. Work to date has estimated the mass and current worth of metals in above ground resources. Using these outcomes as a basis, a typology for different options for (metal) reuse and recycling has been developed to classify the common features, which is presented in this article. In addition, the authors investigate the barriers and enablers in the recycling value chain, and propose a set of requirements for a feasible pathway to close the material loop for metals in Australia

Surface Activity of Graphite Nanomaterials

Presents the results of experimental investigation of surface activity of carbon nanostructures: sensor films on the basis of amorphous nanodispersed carbon, carbon nanofibers and disrupted nanographite. The increase in the electrical resistance of such material at a concentration of vapors of acetone in air is 12000 ppm at room temperature in the order of 4 %. It is shown that the growth of the resistance associated with the change in the concentration of conduction electrons in the contacts between the structural elements of the films

VoIP Traffic Shaping Analyses in Metropolitan Area Networks

This paper represents VoIP shaping analyses in devices that apply the three Quality of Service techniques – IntServ, DiffServ and RSVP. The results show queue management and packet stream shaping based on simulation of the three mostly demanded services – VoIP, LAN emulation and transaction exchange. Special attention is paid to the VoIP as the most demanding service for real time communication