Modulation of gyrosynchrotron emission in solar and stellar flares by slow magnetoacoustic oscillations

Gyrosynchrotron emission generated by non-thermal electrons in solar and stellar coronal flares can be efficiently modulated by slow magnetoacoustic oscillations in the flaring loops. The modulation mechanism is based upon perturbation of the efficiency in the Razin suppression of optically thin gyrosynchrotron emission. Modulation of the emission is in anti-phase with the density perturbation in the slow wave. The observed emission modulation depth can be up to an order of magnitude higher than the slow wave amplitude. This effect is more pronounced at lower frequencies. Observations with spatial resolution, together with analysis of the modulation frequency, are shown to be sufficient for providing the information needed to identify the mode

Graphene Oxide/Reduced Graphene Oxide Aerogels

In this chapter, we will discuss aerogels based on graphene oxide/reduced graphene oxide—promising composite materials, based on 2D carbon nanoparticles, with a certain architecture that prevents aggregation of graphene layers with a highly developed surface that have a high potential technological realization as materials for supercapacitors, sensors, batteries, and actuators. This chapter describes the existing methods for producing composite aerogels based on graphene oxide/reduced graphene oxide, the structural features of these materials, the most relevant studies in the areas of surface modification, architectural control, improvement of mechanical properties, and the most interesting applications. It has been shown that such materials have relatively high specific surface values and a high degree of exfoliation of graphene layers, but an urgent need is to improve them, which is due to the fragility of graphene aerogels and composite materials based on them, as well as the need to modify the surface to control porosity

RELATIONSHIP OF THE CONSTITUTION OF THE RUSSIAN FEDERATION AND INTERNATIONAL LAW

Abstract. The concept of «sovereignty» is taken to be interpreted as a property of state power to beindependent of any other authority, both within the state and outside it, i.e. have absolute legal supremacy. In essence, the sovereignty of the state is the sovereignty of its elite, the so-called political class that controls ownership of natural resources, capital and a system of bureaucratic management. It is important to bear in mind that recognizing the generally recognized principles and norms of international law and international treaties as an integral part of the legal system of the Russian Federation, the Constitution of the Russian Federation, as well as federal legislation and legislation of the constituent entities of the Russian Federation, does not disclose the notion of a legal system that is ambiguously defined in the scientific world . States have the right, in accordance with the principle of not interfering inthe internal affairs of the state, independently, without outside interference and any pressure, to establish their political, economic systems, dispose of natural resources, develop them independently or concessionally, impose taxes and other charges, establish customs rules, regime of stay of foreigners on its territory.Key words: State, society, sovereignty, norms of international law, international legal custom, human rightsand freedom

Friction stir processing on carbon steel

Friction stir processing of medium carbon steel samples has been carried out using a milling machine and toolsmade of cemented tungsten carbide. Samples have been machined from 40 and 40X steels. The tools have been made inthe shape of 5u5u1.5 mm and 3u3u1.5 mm tetrahedrons. The microstructure of stirred zone has been obtained using thesmaller tool and consists of fine recrystallized 2–3 Pm grains, whereas the larger tool has produced the “onion-like”structures comprising hard quenched “white” 500–600 MPa layers with 300–350 MPa interlayers of bainite needles. Themean values of wear intensity obtained after measuring the wear scar width were 0.02 mm/m and 0.001 mm/m for nonprocessedand processed samples, respectively

THE SERBIAN PEOPLE AND THE STATE TO THE TURKISH CONQUEST: THE EXPERIENCE OF HISTORICAL-LEGAL RESEARCH

Purpose: The article analyzes the hypotheses about the Carpathian and Azov ancestral home of the Serbian tribes and the political role of the territory of ancient Raska in the formation of medieval Serbian statehood via comparative legal and historical methods. Methodology: The methodological basis of this study is the dialectical method of cognition of social and legal phenomena and the concepts in their development and interdependence. Data was obtained from scientific, historical, and legal documents. Main Findings: The drafters of the Law sought to overcome the disparity in court proceedings and bring legal norms into a certain system, taking into account the needs of feudalism. The author comes to the conclusion that the preservation of Serbian ethnic identity influenced the restoration of statehood in the XIX century due to the spiritually and economically self-governing zadruge. Applications: This research can be used by historical organizations, educational organizations as well as by history scholars. Novelty/Originality: Serbian people and Turkish conquest has been studied using historical-legal documents

Prospects of the WSR-88D Radar for Cloud Studies

This is the publisher's version, also available electronically from http://journals.ametsoc.org/doi/abs/10.1175/2010JAMC2303.1.Sounding of nonprecipitating clouds with the 10-cm wavelength Weather Surveillance Radar-1988 Doppler (WSR-88D) is discussed. Readily available enhancements to signal processing and volume coverage patterns of the WSR-88D allow observations of a variety of clouds with reflectivities as low as −25 dBZ (at a range of 10 km). The high sensitivity of the WSR-88D, its wide velocity and unambiguous range intervals, and the absence of attenuation allow accurate measurements of the reflectivity factor, Doppler velocity, and spectrum width fields in clouds to ranges of about 50 km. Fields of polarimetric variables in clouds, observed with a research polarimetric WSR-88D, demonstrate an abundance of information and help to resolve Bragg and particulate scatter. The scanning, Doppler, and polarimetric capabilities of the WSR-88D allow real-time, three-dimensional mapping of cloud processes, such as transformations of hydrometeors between liquid and ice phases. The presence of ice particles is revealed by high differential reflectivities and the lack of correlation between reflectivity and differential reflectivity in clouds in contrast to that found for rain. Pockets of high differential reflectivities are frequently observed in clouds; maximal values of differential reflectivity exceed 8 dB, far above the level observed in rain. The establishment of the WSR-88D network consisting of 157 polarimetric radars can be used to collect cloud data at any radar site, making the network a potentially powerful tool for climatic studies

Three-Loop Radiative-Recoil Corrections to Hyperfine Splitting in Muonium

We calculate three-loop radiative-recoil corrections to hyperfine splitting in muonium generated by the diagrams with the first order electron and muon polarization loop insertions in graphs with two exchanged photons. These corrections are enhanced by the large logarithm of the electron-muon mass ratio. The leading logarithm squared contribution was obtained a long time ago. Here we calculate the single-logarithmic and nonlogarithmic contributions. We previously calculated the three-loop radiative-recoil corrections generated by two-loop polarization insertions in the exchanged photons. The current paper therefore concludes calculation of all three-loop radiative-recoil corrections to hyperfine splitting in muonium generated by diagrams with closed fermion loop insertions in the exchanged photons. The new results obtained here improve the theory of hyperfine splitting, and affect the value of the electron-muon mass ratio extracted from experimental data on the muonium hyperfine splitting.Comment: 27 pages, 6 figures, 7 table

Alterations in Lipid Levels of Mitochondrial Membranes Induced by Amyloid-β: A Protective Role of Melatonin

Alzheimer pathogenesis involves mitochondrial dysfunction, which is closely related to amyloid-β (Aβ) generation, abnormal tau phosphorylation, oxidative stress, and apoptosis. Alterations in membranal components, including cholesterol and fatty acids, their characteristics, disposition, and distribution along the membranes, have been studied as evidence of cell membrane alterations in AD brain. The majority of these studies have been focused on the cytoplasmic membrane; meanwhile the mitochondrial membranes have been less explored. In this work, we studied lipids and mitochondrial membranes in vivo, following intracerebral injection of fibrillar amyloid-β (Aβ). The purpose was to determine how Aβ may be responsible for beginning of a vicious cycle where oxidative stress and alterations in cholesterol, lipids and fatty acids, feed back on each other to cause mitochondrial dysfunction. We observed changes in mitochondrial membrane lipids, and fatty acids, following intracerebral injection of fibrillar Aβ in aged Wistar rats. Melatonin, a well-known antioxidant and neuroimmunomodulator indoleamine, reversed some of these alterations and protected mitochondrial membranes from obvious damage. Additionally, melatonin increased the levels of linolenic and n-3 eicosapentaenoic acid, in the same site where amyloid β was injected, favoring an endogenous anti-inflammatory pathway

Effect of the moderate and high intensity chronic exercise on plasma tumor necrosis factor alpha and Langerhans islets histology in healthy rats

Tumor necrosis factor alpha (TNF-α), a pro-inflammatory cytokine, negatively affects β-cell physiology and morphology, as occurs during type 1 diabetes mellitus and metabolic syndrome. Physical exercise is a good tool to reduce the pro-inflammatory state. PURPOSE: The present study investigated the effects of moderate and high-intensity chronic exercise on plasma TNF-α levels in a basal state; it further analyzed whether these cytokine changes are associated with changes in the pancreatic Langerhans islets morphology under healthy state. METHODS: Two month-old healthy male Wistar rats were divided into three groups: control (C) (n = 7), moderate intensity training (MIT) (n = 7), and high intensity training (HIT) (n = 5). The training protocol consisted of 24 exercise sessions, which involved running in a treadmill. The training intensity was 60% of the maximal oxygen consumption (VO2max) for MIT and 80% VO2max for HIT. Forty-eight hours after the last training session, plasma samples were obtained from the three groups to determine TNF-α and insulin levels with ELISA method. The duodenal pancreas was dissected to analyze the Langerhans islets. The correlation analysis among the nuclei/total islet area was carried out. RESULTS: The HIT group showed lower TNF-α plasma levels compared with the C group. Systemic insulin levels were not significantly modified in basal state by the chronic exercise intensity. In addition all the experimental groups showed a positive nuclei/islet area correlation. CONCLUSIONS: Under healthy conditions, the high intensity training reduces the plasma TNF-α level, but this effect is not associated with functionality or morphology changes of the pancreatic Langerhans islets. This study emphasizes the importance of one threshold in the exercise training to reduce the plasmatic TNF-α levels in a healthy state model

Accumulation of Exogenous Amyloid-Beta Peptide in Hippocampal Mitochondria Causes Their Dysfunction: A Protective Role for Melatonin

Amyloid-beta (Aβ) pathology is related to mitochondrial dysfunction accompanied by energy reduction and an elevated production of reactive oxygen species (ROS). Monomers and oligomers of Aβ have been found inside mitochondria where they accumulate in a time-dependent manner as demonstrated in transgenic mice and in Alzheimer's disease (AD) brain. We hypothesize that the internalization of extracellular Aβ aggregates is the major cause of mitochondrial damage and here we report that following the injection of fibrillar Aβ into the hippocampus, there is severe axonal damage which is accompanied by the entrance of Aβ into the cell. Thereafter, Aβ appears in mitochondria where it is linked to alterations in the ionic gradient across the inner mitochondrial membrane. This effect is accompanied by disruption of subcellular structure, oxidative stress, and a significant reduction in both the respiratory control ratio and in the hydrolytic activity of ATPase. Orally administrated melatonin reduced oxidative stress, improved the mitochondrial respiratory control ratio, and ameliorated the energy imbalance