Compton effect on relativistic electrons in the atmosphere of the sun

Compton effect on relativistic electrons in solar atmospher

Configuration and Performance of a Mobile 129Xe Polarizer

A stand-alone, self-contained and transportable system for the polarization of (129)Xe by spin exchange optical pumping with Rb is described. This mobile polarizer may be operated in batch or continuous flow modes with medium amounts of hyperpolarized (129)Xe for spectroscopic or small animal applications. A key element is an online nuclear magnetic resonance module which facilitates continuous monitoring of polarization generation in the pumping cell as well as the calculation of the absolute (129)Xe polarization. The performance of the polarizer with respect to the crucial parameters temperature, xenon and nitrogen partial pressures, and the total gas flow is discussed. In batch mode the highest (129)Xe polarization of P(Xe) = 40 % was achieved using 0.1 mbar xenon partial pressure. For a xenon flow of 6.5 and 26 mln/min, P(Xe) = 25 % and P(Xe) = 13 % were reached, respectively. The mobile polarizer may be a practical and efficient means to make the applicability of hyperpolarized (129)Xe more widespread

Machine-Learning Based Smoke Detection

A machine learning based arrangement can be used to more accurately detect whether a smoke alarm should be sounded based on a determined rate of change in the measured amount of smoke. The machine learning model may be pre-trained based on training data then executed by a smoke detector to accurately distinguish between likely emergencies and nuisance conditions

Inverse Compton X-rays from relativistic flare electrons and positrons

<p><b>Context:</b> In solar flares, inverse Compton scattering (ICS) of photospheric photons might give rise to detectable hard X-ray photon fluxes from the corona where ambient densities are too low for significant bremsstrahlung or recombination. γ-ray lines and continuum in some large flares imply the presence of the necessary ~100 MeV electrons and positrons, the latter as by-products of GeV energy ions. Recent observations of coronal hard X-ray sources in particular prompt us to reconsider here the possible contribution of ICS.</p> <p><b>Aims:</b> We aim to evaluate the ICS X-ray fluxes to be expected from prescribed populations of relativistic electrons and positrons in the solar corona. The ultimate aim is to determine if ICS coronal X-ray sources might offer a new diagnostic window on relativistic electrons and ions in flares.</p> <p><b>Methods:</b> We use the complete formalism of ICS to calculate X-ray fluxes from possible populations of flare primary electrons and secondary positrons, paying attention to the incident photon angular distribution near the solar surface and thus improving on the assumption of isotropy made in previous solar discussions.</p> <p><b>Results:</b> Both primary electrons and secondary positrons produce very hard ICS X-ray spectra. The anisotropic primary radiation field results in pronounced centre-to-limb variation in predicted fluxes and spectra, with the most intense spectra, extending to the highest photon energies, expected from limb flares. Acceptable numbers of electrons or positrons could account for RHESSI coronal X/γ-ray sources.</p> <p><b>Conclusions:</b> Some coronal X-ray sources at least might be interpreted in terms of ICS by relativistic electrons or positrons, particularly when sources appear at such low ambient densities that bremsstrahlung appears implausible.</p&gt

Broadband microwave burst produced by electron beams

Theoretical and experimental study of fast electron beams attracts a lot of attention in the astrophysics and laboratory. In the case of solar flares the problem of reliable beam detection and diagnostics is of exceptional importance. This paper explores the fact that the electron beams moving oblique to the magnetic field or along the field with some angular scatter around the beam propagation direction can generate microwave continuum bursts via gyrosynchrotron mechanism. The characteristics of the microwave bursts produced by beams differ from those in case of isotropic or loss-cone distributions, which suggests a new tool for quantitative diagnostics of the beams in the solar corona. To demonstrate the potentiality of this tool, we analyze here a radio burst occurred during an impulsive flare 1B/M6.7 on 10 March 2001 (AR 9368, N27W42). Based on detailed analysis of the spectral, temporal, and spatial relationships, we obtained firm evidence that the microwave continuum burst is produced by electron beams. For the first time we developed and applied a new forward fitting algorithm based on exact gyrosynchrotron formulae and employing both the total power and polarization measurements to solve the inverse problem of the beam diagnostics. We found that the burst is generated by a oblique beam in a region of reasonably strong magnetic field ($\sim 200-300$ G) and the burst is observed at a quasi-transverse viewing angle. We found that the life time of the emitting electrons in the radio source is relatively short, $\tau_l \approx 0.5$ s, consistent with a single reflection of the electrons from a magnetic mirror at the foot point with the stronger magnetic field. We discuss the implications of these findings for the electron acceleration in flares and for beam diagnostics.Comment: Astrophysical Journal, accepted: 26 pages, 8 figure

The Arctic territories of Russia: long-term dynamics of the social space

The Arctic territories of Russia were explored and populated rigorously and purposefully during the Soviet period. The settling pattern was then based on the industrial capabilities of the Arctic areas (mineral deposits), considering the need to develop relevant transport infrastructure. The incentive component of the Soviet propaganda of Arctic development was aimed at mobilizing the skilled workforce. The market transformation in the late 20th century caused a rapid deterioration in the social and economic situation nation-wide: the state abandoned protectionism of the Arctic territories so that state-provided preferences were significantly reduced. Such transformations eventually entailed the reduction of social and economic services and a large-scale migration outflow in the Arctic territories. The current social and economic situation in the Arctic is still characterized by a negative migration balance, which determines a decline in the level of labor force participation. The negative migration balance is attributable to the lower economic attractiveness of the region, which again brings about the issue of unemployment in the Arctic. Destructive processes in the social and economic development of the Arctic territories of Russia shape multi-faceted threats to its stable evolution. Thus, the analysis of the long-term pattern of the social space in the Arctic territories of Russia is an essential aspect of new emerging conceptual approaches towards research and practical plan for Arctic development. The purpose of the survey was to review the pattern of the social space in the modern Arctic territories of Russia between 1950 and 2018, with one of its objectives being the analysis of its social development stages based on historiographic, problematic / chronological, retrospective and comparative-historical methods. The survey shows that transformations in the consistent long-term pattern of the social space in the modern Arctic territories of Russia are determined by the intensity of its industrial development, the scale of government support, and the long-term interests of the national economy

Development of technology for the hemp stalks preparation

Getting high-quality trusts in modern technology for growing technical hemp is one of the most labor-intensive processes.The main factors that cause loss of quality of hemp are determined by the level of perfection of the harvesting stage of the production process. It is precisely at this stage that the basic processes of product quality management are concentrated, the main physical and technological losses are taking place.The main drawbacks of the known methods of obtaining the trusts of technical hemp include the dependence of the process of forming its qualitative indicators on weather conditions, the unevenness of the separation and strength of the fiber on the entire mass of the sent layer, the length of the technological process, which determines the quantitative loss of production.The article presents the results of research on the development of resource-saving technology for the production of technical hemp trusts due to the addition of an outlet with improved water drains with reeds and finger-wheels and the direct effect of their constructive parameters on the quality indicators of the trust.Mechanized technological processes are carried out thanks to the developed unit, which includes: a modernized corrugated water pump, hay rakes and a roll baler.It was noted that an increase in the number of mechanical influences on the hemp strap ribbon leads to a corresponding decrease in its height and mass. The loosening process reduces the weight of the tape to 2.1 kg per linear meter. Under these conditions, the height of the windrow increases to 35.0 cm. Techniques for obtaining a hedge trustee make it possible to reduce the time of process implementation at the initial stages of its preparation for primary processing, intensifies the process of purification due to the additional mechanical drive with improved aggregates. The short fiber obtained from the hemp trust for the technology developed meets the existing requirements

The role of labor potential in the sustainable development of the Russian Arctic

The key to the effective development of the Arctic resources is the active development of elements of the socio-economic systems of the Arctic territories. The progress in their use will provide a synergistic effect in the implementation of the full range of development priorities of the Arctic zone. One of these elements is labor potential, able to confront challenges in the Arctic effectively. Modern problems of the development of the labor potential of the Arctic territories are population decline, disruption of population reproduction processes, the low life expectancy of men and native people, social tensions in labor markets, and poverty. The provisions and conclusions of the presented study contain a scientifically substantiated position regarding the role of labor potential in the sustainable development of the Arctic territories of Russia. The research results are focused on their use for managing the development of the labor potential of the Arctic territories. Prospects for the further research of this topic are related to the study of the scientific foundations of the territorial self-development in achieving sustainable development of the Arctic territories of Russia