Wave-induced loss of ultra-relativistic electrons in the Van Allen radiation belts.

The dipole configuration of the Earth's magnetic field allows for the trapping of highly energetic particles, which form the radiation belts. Although significant advances have been made in understanding the acceleration mechanisms in the radiation belts, the loss processes remain poorly understood. Unique observations on 17 January 2013 provide detailed information throughout the belts on the energy spectrum and pitch angle (angle between the velocity of a particle and the magnetic field) distribution of electrons up to ultra-relativistic energies. Here we show that although relativistic electrons are enhanced, ultra-relativistic electrons become depleted and distributions of particles show very clear telltale signatures of electromagnetic ion cyclotron wave-induced loss. Comparisons between observations and modelling of the evolution of the electron flux and pitch angle show that electromagnetic ion cyclotron waves provide the dominant loss mechanism at ultra-relativistic energies and produce a profound dropout of the ultra-relativistic radiation belt fluxes

Chemical analysis of aerosol in the Venusian cloud layer by reaction gas chromatography on board the Vega landers

The experiment on sulfuric acid aerosol determination in the Venusian cloud layer on board the Vega landers is described. An average content of sulfuric acid of approximately 1 mg/cu m was found for the samples taken from the atmosphere at heights from 63 to 48 km and analyzed with the SIGMA-3 chromatograph. Sulfur dioxide (SO2) was revealed in the gaseous sample at the height of 48 km. From the experimental results and blank run measurements, a suggestion is made that the Venusian cloud layer aerosol consists of more complicated particles than the sulfuric acid water solution does

The nonlinear time-dependent response of isotactic polypropylene

Tensile creep tests, tensile relaxation tests and a tensile test with a constant rate of strain are performed on injection-molded isotactic polypropylene at room temperature in the vicinity of the yield point. A constitutive model is derived for the time-dependent behavior of semi-crystalline polymers. A polymer is treated as an equivalent network of chains bridged by permanent junctions. The network is modelled as an ensemble of passive meso-regions (with affine nodes) and active meso-domains (where junctions slip with respect to their positions in the bulk medium with various rates). The distribution of activation energies for sliding in active meso-regions is described by a random energy model. Adjustable parameters in the stress--strain relations are found by fitting experimental data. It is demonstrated that the concentration of active meso-domains monotonically grows with strain, whereas the average potential energy for sliding of junctions and the standard deviation of activation energies suffer substantial drops at the yield point. With reference to the concept of dual population of crystalline lamellae, these changes in material parameters are attributed to transition from breakage of subsidiary (thin) lamellae in the sub-yield region to fragmentation of primary (thick) lamellae in the post-yield region of deformation.Comment: 29 pages, 12 figure

Моделирование системы природопользования на железных дорогах

[For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version)].ABSTRACT The article considers the strategy of creation of ecological and economic system of nature management at enterprises of the railway industry. The process of managing such a system is revealed with the help of game theory and the construction of a game-theoretic model of development. The model proposed by the authors can serve as a basis for constructing an innovative scenario in which the possibility of combining, in a strategic perspective and under given initial conditions, the economic benefits and goals of state environmental policy, corporate environmental programs, is mathematically proven. Keywords: ecological safety, strategic planning, management, economy, nature management system, railway transport, game theory, development model.Текст аннотации на англ. языке и полный текст статьи на англ. языке находится в прилагаемом файле ПДФ (англ. версия следует после русской версии).В статье рассмотрена стратегия создания эколого-экономической по своему предназначению системы природопользования на предприятиях железнодорожной отрасли. Процесс управления такой системой раскрывается с помощью теории игр и построения теоретико-игровой модели развития. Предложенная авторами модель может служить основой построения инновационного сценария, в котором математически доказана возможность соединить в стратегической перспективе и при заданных начальных условиях экономическую выгоду и цели государственной экологической политики, корпоративных природоохранных программ

Gradual diffusion and punctuated phase space density enhancements of highly relativistic electrons: Van Allen Probes observations

Abstract The dual-spacecraft Van Allen Probes mission has provided a new window into mega electron volt (MeV) particle dynamics in the Earth\u27s radiation belts. Observations (up to E ~10 MeV) show clearly the behavior of the outer electron radiation belt at different timescales: months-long periods of gradual inward radial diffusive transport and weak loss being punctuated by dramatic flux changes driven by strong solar wind transient events. We present analysis of multi-MeV electron flux and phase space density (PSD) changes during March 2013 in the context of the first year of Van Allen Probes operation. This March period demonstrates the classic signatures both of inward radial diffusive energization and abrupt localized acceleration deep within the outer Van Allen zone (L ~4.0 ± 0.5). This reveals graphically that both competing mechanisms of multi-MeV electron energization are at play in the radiation belts, often acting almost concurrently or at least in rapid succession. Key Points Clear observations to higher energy than ever before Precise detection of where and how acceleration takes place Provides new eyes on megaelectron Volt

Fermionic Vacuum Energy from a Nielsen-Olesen Vortex

We calculate the vacuum energy of a spinor field in the background of a Nielsen-Olesen vortex. We use the method of representing the vacuum energy in terms of the Jost function on the imaginary momentum axis. Renormalization is carried out using the heat kernel expansion and zeta functional regularization. With this method well convergent sums and integrals emerge which allow for an efficient numerical calculation of the vacuum energy in the given case where the background is not known analytically but only numerically. The vacuum energy is calculated for several choices of the parameters and it turns out to give small corrections to the classical energy.Comment: 22 pages, 6 figure

Economic benefit of using testosterone gel (used externally) in men with diabetes mellitus and testosterone deficiency

BACKGROUND: High prevalence of type 2 diabetes mellitus (T2DM) and its input to the increase of mortality indicate that social and economic value of this disease and financial burden are great. Testosterone replacement therapy (TRT) enhances the effectiveness of T2DM treatment. A research was conducted to assess if Androgel® therapy in diabetic men is cost-effective. OBJECTIVES: Defining of economic benefit of adding “Androgel” to the T2DM treatment in men with testosterone deficiency. MATERIALS AND METHODS: Economic modeling and results of other clinical studies were used in the analysis. A guildeline of The Scottish Intercollegiate Guidelines Network (SIGN) was used for clinical study selection, development of economic modelling and study design, assessment of study quality. The study analyzed clinical effects (fasting morning glycemia, glycosylated hemoglobin, HOMA index) and mortality reduce. RESULTS: It was shown that TRT can help to reduce costs of glycemic control, to increase efficiency in terms of cost-effectiveness analysis. Target HbA1c value can be reached by additional cost of 569.39 roubles for every patient. There is a possible additional income from 454.100 to 8.896.186 rubles though reduced mortality. CONCLUSION: Thus, testosterone replacement therapy was shown as cost effective due to reduced costs. The analysis demonstrated HbA1c target achievement and, as a result, reduction of the T2DM outcomes and reduced mortality. There is a possible additional income from 454.100 to 8.896.186 rubles per year

Effect of EMIC waves on relativistic and ultrarelativistic electron populations: Ground-based and Van Allen Probes observations

Abstract We study the effect of electromagnetic ion cyclotron (EMIC) waves on the loss and pitch angle scattering of relativistic and ultrarelativistic electrons during the recovery phase of a moderate geomagnetic storm on 11 October 2012. The EMIC wave activity was observed in situ on the Van Allen Probes and conjugately on the ground across the Canadian Array for Real-time Investigations of Magnetic Activity throughout an extended 18 h interval. However, neither enhanced precipitation of \u3e0.7 MeV electrons nor reductions in Van Allen Probe 90° pitch angle ultrarelativistic electron flux were observed. Computed radiation belt electron pitch angle diffusion rates demonstrate that rapid pitch angle diffusion is confined to low pitch angles and cannot reach 90°. For the first time, from both observational and modeling perspectives, we show evidence of EMIC waves triggering ultrarelativistic (~2-8 MeV) electron loss but which is confined to pitch angles below around 45° and not affecting the core distribution. Key Points EMIC wave activity is not associated with precipitation of MeV electrons EMIC waves do not deplete the ultra-relativistic belt down to 90° EMIC waves cause loss of low pitch angle electrons with energies ~2-8 MeV