Generation of Electron Beam Plasma inside the Dielectric Tube

The results of experimental study of electron beam plasma inside the dielectric tube are presented. Beam plasma was generated by the fore-vacuum plasma electron source at (2-10) Pa in dc mode. It is shown, that the dependence of the plasma potential on gas pressure inside the tube is completely different in comparison with similar dependence without a tube. Monotonic dependence of the insulated beam col-lector potential in the tube on beam energy has two stages: slow and fast growth

A METHOD FOR THE ESTIMATION OF TSUNAMI RISK ALONG RUSSIA’s FAR EAST

A simplified method was developed for estimating the tsunami risk for a coast for possible events having recurrence periods of 50 and 100 years. The method is based on readily available seismic data and the calculation of magnitudes of events with specified return periods. A classical Gumbel statistical method was used to estimate magnitudes of small probability events. The tsunami numerical modeling study used the average earthquake coordinates in the Kuril-Kamchatka high- seismic area. The verification and testing of the method were carried out using events from the North, Middle and South Kuril Islands – the most tsunami-risk areas of Russia’s Far East. Also, the study used the regional Kuril-Kamchatka catalogue of earthquakes from 1900 to 2008 - which included earthquakes with magnitudes of at least M=6. The results of the study indicate that the proposed methodology provides reasonable estimates of tsunami risk

Automated search for star clusters in large multiband surveys: II. Discovery and investigation of open clusters in the Galactic plane

Automated search for star clusters in J,H,K_s data from 2MASS catalog has been performed using the method developed by Koposov et. al (2008). We have found and verified 153 new clusters in the interval of the galactic latitude -24 < b < 24 degrees. Color excesses E(B-V), distance moduli and ages were determined for 130 new and 14 yet-unstudied known clusters. In this paper, we publish a catalog of coordinates, diameters, and main parameters of all the clusters under study. A special web-site available at http://ocl.sai.msu.ru has been developed to facilitate dissemination and scientific usage of the results.Comment: 9 pages, 3 tables, 5 figures, accepted to Astronomy Letter

FAVOR (FAst Variability Optical Registration) -- A Two-telescope Complex for Detection and Investigation of Short Optical Transients

An astronomical complex intended to detect optical transients (OTs) in a wide field and follow them up with high time resolution investigation is described.Comment: 4 pages, 3 figures. To be published in "Il Nuovo Cimento", Proceedings of the 4th Rome Workshop on Gamma-Ray Bursts in the Afterglow Era, eds. L. Piro, L. Amati, S. Covino, B. Gendr

The XMM-Newton serendipitous survey. VII. The third XMM-Newton serendipitous source catalogue

Thanks to the large collecting area (3 x ~1500 cm$^2$ at 1.5 keV) and wide field of view (30' across in full field mode) of the X-ray cameras on board the European Space Agency X-ray observatory XMM-Newton, each individual pointing can result in the detection of hundreds of X-ray sources, most of which are newly discovered. Recently, many improvements in the XMM-Newton data reduction algorithms have been made. These include enhanced source characterisation and reduced spurious source detections, refined astrometric precision, greater net sensitivity and the extraction of spectra and time series for fainter sources, with better signal-to-noise. Further, almost 50\% more observations are in the public domain compared to 2XMMi-DR3, allowing the XMM-Newton Survey Science Centre (XMM-SSC) to produce a much larger and better quality X-ray source catalogue. The XMM-SSC has developed a pipeline to reduce the XMM-Newton data automatically and using improved calibration a new catalogue version has been produced from XMM-Newton data made public by 2013 Dec. 31 (13 years of data). Manual screening ensures the highest data quality. This catalogue is known as 3XMM. In the latest release, 3XMM-DR5, there are 565962 X-ray detections comprising 396910 unique X-ray sources. For the 133000 brightest sources, spectra and lightcurves are provided. For all detections, the positions on the sky, a measure of the quality of the detection, and an evaluation of the X-ray variability is provided, along with the fluxes and count rates in 7 X-ray energy bands, the total 0.2-12 keV band counts, and four hardness ratios. To identify the detections, a cross correlation with 228 catalogues is also provided for each X-ray detection. 3XMM-DR5 is the largest X-ray source catalogue ever produced. Thanks to the large array of data products, it is an excellent resource in which to find new and extreme objects.Comment: 23 pages, version accepted for publication in A&

Nitriding of titanium in electron beam excited plasma in medium vacuum

We report our results on nitriding of industrially-pure titanium VT1-0 in the plasma formed by continuous electron beam created by a fore-vacuum plasma-cathode electron source, at different temperatures of the titanium sample surface (700–1020 °C) and electron beam energy (4–6 keV), in medium vacuum (5 Pa) of nitrogen. Electron beam was used for direct treatment and heating of the sample as well as for the plasma generation. It is demonstrated that such parameters of the Ti sample as nitrogen content, the depth of nitride layer, Vickers microhardness, and wear-resistance grow with sample temperature and beam energy. Such positive effects happen, likely, due to enhanced generation of active atoms and atomic ions of nitrogen in beam-produced plasmas in medium vacuum

Aerodynamic investigations of ventilated brake discs.

The heat dissipation and performance of a ventilated brake disc strongly depends on the aerodynamic characteristics of the flow through the rotor passages. The aim of this investigation was to provide an improved understanding of ventilated brake rotor flow phenomena, with a view to improving heat dissipation, as well as providing a measurement data set for validation of computational fluid dynamics methods. The flow fields at the exit of four different brake rotor geometries, rotated in free air, were measured using a five-hole pressure probe and a hot-wire anemometry system. The principal measurements were taken using two-component hot-wire techniques and were used to determine mean and unsteady flow characteristics at the exit of the brake rotors. Using phase-locked data processing, it was possible to reveal the spatial and temporal flow variation within individual rotor passages. The effects of disc geometry and rotational speed on the mean flow, passage turbulence intensity, and mass flow were determined. The rotor exit jet and wake flow were clearly observed as characterized by the passage geometry as well as definite regions of high and low turbulence. The aerodynamic flow characteristics were found to be reasonably independent of rotational speed but highly dependent upon rotor geometry

Electron beam nitriding of titanium in medium vacuum

We describe a novel method for electron-beam nitriding of metal (titanium) under medium (fore-vacuum) pressures (2–8 Pa) of nitrogen. Titanium sample was heated by a dc electron beam generated by a fore-vacuum plasma-cathode electron source with current up to 100 mA and energy up to 8 kV; this beam also generated beam-produced plasma with active nitrogen atoms, ions and other reactive species near the sample. SEM chemical composition analysis of the nitride layer have shown the presence of approximately 25 wt% of N, wt. 68% of Ti and only wt. 6% of O atoms within the processed layer. The X-ray diffraction spectrum of the nitride sample showed that the modified layer has a crystalline structure predominantly orientated along the crystallographic directions (111), (200), (220), characteristic of δ-TiN with a face-centered lattice. Besides the δ-TiN phase, there are present in the nitrided layer a γ phase of Ti2N (tetragonal nitride) with predominant orientation (200). These results show the advantage of using forevacuum sources for electron beam and plasma nitriding of metals

Lung adenocarcinoma originates from retrovirus infection of proliferating type 2 pneumocytes during pulmonary post-natal development or tissue repair

Jaagsiekte sheep retrovirus (JSRV) is a unique oncogenic virus with distinctive biological properties. JSRV is the only virus causing a naturally occurring lung cancer (ovine pulmonary adenocarcinoma, OPA) and possessing a major structural protein that functions as a dominant oncoprotein. Lung cancer is the major cause of death among cancer patients. OPA can be an extremely useful animal model in order to identify the cells originating lung adenocarcinoma and to study the early events of pulmonary carcinogenesis. In this study, we demonstrated that lung adenocarcinoma in sheep originates from infection and transformation of proliferating type 2 pneumocytes (termed here lung alveolar proliferating cells, LAPCs). We excluded that OPA originates from a bronchioalveolar stem cell, or from mature post-mitotic type 2 pneumocytes or from either proliferating or non-proliferating Clara cells. We show that young animals possess abundant LAPCs and are highly susceptible to JSRV infection and transformation. On the contrary, healthy adult sheep, which are normally resistant to experimental OPA induction, exhibit a relatively low number of LAPCs and are resistant to JSRV infection of the respiratory epithelium. Importantly, induction of lung injury increased dramatically the number of LAPCs in adult sheep and rendered these animals fully susceptible to JSRV infection and transformation. Furthermore, we show that JSRV preferentially infects actively dividing cell in vitro. Overall, our study provides unique insights into pulmonary biology and carcinogenesis and suggests that JSRV and its host have reached an evolutionary equilibrium in which productive infection (and transformation) can occur only in cells that are scarce for most of the lifespan of the sheep. Our data also indicate that, at least in this model, inflammation can predispose to retroviral infection and cancer