Proton acceleration in analytic reconnecting current sheets

Particle acceleration provides an important signature for the magnetic collapse that accompanies a solar flare. Most particle acceleration studies, however, invoke magnetic and electric field models that are analytically convenient rather than solutions of the governing magnetohydrodynamic equations. In this paper a self-consistent magnetic reconnection solution is employed to investigate proton orbits, energy gains, and acceleration timescales for proton acceleration in solar flares. The magnetic field configuration is derived from the analytic reconnection solution of Craig and Henton. For the physically realistic case in which magnetic pressure of the current sheet is limited at small resistivities, the model contains a single free parameter that specifies the shear of the velocity field. It is shown that in the absence of losses, the field produces particle acceleration spectra characteristic of magnetic X-points. Specifically, the energy distribution approximates a power law ~ξ-3/2 nonrelativistically, but steepens slightly at the higher energies. Using realistic values of the “effective” resistivity, we obtain energies and acceleration times that fall within the range of observational data for proton acceleration in the solar corona

ВИДОВИЙ СКЛАД ТА СТАН РАРИТЕТНИХ ДЕНДРОЕКЗОТІВ ВІДДІЛУ PINOPHYTA БОТАНІЧНОГО САДУ ЧЕРНІВЕЦЬКОГО НАЦІОНАЛЬНОГО УНІВЕРСИТЕТУ ІМЕНІ ЮРІЯ ФЕДЬКОВИЧА

An effective direction of rare exotic plant species preservation is their ex situ cultivation conditions that is realized for introduced plants in botanical gardens, dendrological parks and other preserved parks. Lately, first actions for preservation rare woody plants in ex situ conditions in Ukraine are inventory research, elucidation of their spreading in cultivated area, their conservation status due to the Red Lists of international significance (such as The IUСN Red List of Threatened Species) and estimation of their adaptation level. Therefore, the purpose of our research is to analyze species composition, conservation status due to The IUСN Red List of Threatened Species, geographical origin, taxation parameters, winter resistance and generative development of Pinophyta rare woody exotic plants cultivated in Chernivtsi National University Botanical Garden. At the beginning of 2018, 39 species of rare dendroexotic plants of Pinophyta are growing in the open ground conditions in Botanical Garden. They belong to 20 genus, 4 families. The authors have ascertained that 19 species originated in East Asia and 14 species are from North America. 51. 3 % of species are endemics and 3 species are relicts. All species are recorded in The Red List of Threatened Species and are distributed by 5 categories; species from LC category are predominated (26 species). According to The IUCN Red List, all species that belong to EN (Endangered) and CR (Critically Endangered) categories and 4 species of NT (Near Threatened) category are endemics, so they need special conservation actions. 33 species are trees (29 among them are trees of first magnitude) and 3 species are shrubs. All species retain the growth form, while 7 species have reached the typical height for them. 35 species are revealed to be completely winter-hardly. 22 species form seeds and 5 species are self-propagated. Thus, Pinophyta rare woody exotic plants of Chernivtsi National University Botanical Garden are valuable as a reserve of genetic material and plants in the scientific and educational meaning. Trees of 10 species that have a special historical, collectible and scientific value are pointed out; they are from 110 to above 140 years old. Investigated plants have also forestry, meliorative, decorative and medicinal value. Further successful preservation of these species in the Pre-Carpathian region will be possible if their resistance to biotic factors, ecological and coenotic peculiarities is studied.Наведено результати аналізу видового складу, географічного походження, таксаційних показників, зимостійкості, здатності до генеративного розвитку та розподілу за категоріями раритетності згідно до Червоним списком МСОП деревних інтродуцентів відділу Pinophyta ботанічного саду Чернівецького національного університету ім. Юрія Федьковича. З'ясовано, що в умовах відкритого ґрунту Саду зростає 39 видів раритетних дендроекзотів відділу Pinophyta із 20 родів, 4 родин. Проведено розподіл за категоріями раритетності відповідно до критеріїв Червоного списку МСОП і показано, що 66,7 % досліджуваних видів належить до таких, які перебуває під невеликою загрозою (категорія LC). Природоохоронний статус 17,9 % видів відповідає категоріям CR, EN і VU. За географічним походженням, домінують представники Східної Азії (19 видів) та Північної Америки (14 видів); ендемічними є 51,3 % видів. Установлено, що в умовах Саду всі види зберігають притаманну їм форму росту, при цьому 7 видів досягли характерної для них висоти. Абсолютно зимостійкими в умовах ботанічного саду є 35 видів; формують насіння – 22 види, з них розмножуються самосівом 5 видів. Виділено представників, які мають особливу історичну, колекційну і наукову цінність. Подальшому успішному збереженню досліджуваних видів в умовах Передкарпаття сприятимуть вивчення їхньої стійкості до біотичних факторів та з'ясування еколого-ценотичних особливостей

Дендросозофіти ботанічного саду Чернівецького національного університету імені Юрія Федьковича

Collection of information about specific composition, distribution and state of cultivated rare arboreous plants is an important step in creation of conservation measures for these species ex-situ condition. But such information for Chernivtsi region outlined only partially. So, the purpose of our research was to analyze specific composition, their conservation status due to The IUСN Red List of Threatened Species and to evaluate the acclimatization degree of rare aboriginal and introduced arboreous plants cultivated in the Chernivtsi National University Botanic Garden. Conservation status of these species we determined due to The IUСN Red List of Threatened Species, European Red List of Vascular Plants and Red Data Book of Ukraine (2009). Estimation of acclimatization degree, accordingly to M. A. Kochno scale, includes growth, generative development, winter and drought resistance. To the beginning of 2019, 211 species of arboreous plants are growing in the open ground conditions in the Chernivtsi National University Botanic Garden. They are from 87 genus 37 families 2 orders. All species are recorded to The IUCN Red List of Threatened Species and are distributed by 6 categories: 5 of them – to the category CR, 11 species – to EN, 4 – to VU, 9 – to NT, 166 – to LC and 15 species – to the DD category. In the European Red List of Vascular Plants we found 9 species and in the Red Data Book of Ukraine – 7 species. 192 species adapted to the conditions of cultivation completely, and therefore have a higher degree of acclimatization (I). 16 species adapted to cultivation conditions slightly (degree of acclimatization is II), and the degree of acclimatization of 3 species (Diospyros lotus L., Laurocerasus officinalis Roem., Ilex aquifolium L.) varies depending on winter conditions. 174 species in the Botanic Garden form a viable seed. The rest of the species do not fructify because of their young age (11 species), cultivation under the inappropriate ecological conditions (13 species), flowering in the autumn-winter period (Hamamelis virginiana L.). The dioecious species, which are represented only by the male in the Botanic Garden, do not form seeds too. Non-viable seeds form Taxodium distichum (L.) Rich. and Sequoiadendron giganteum Lindl. Consequently, from a group of threatened species (category CR, EN, VU) does not form seeds only 1 of them. High adaptive parameters and the ability to seed reproduction of the majority of investigated species indicate that the collections of the Chernivtsi National University Botanic Garden have high potential for the effective conservation ex-situ of rare arboreous plants.Встановлено, що у ботанічному саду Чернівецького національного університету в умовах відкритого ґрунту зростає 211 видів дендросозофітів із 87 родів, 37 родин, 2 відділів. Серед них із відділу Pinophyta провідними за кількістю видів є роди Pinus L., Abies Mill., Picea Dietr., Juniperus L., а із Magnoliophyta – Rhododendron L., Magnolia L., Acer L., Quercus L., Malus Mill. У Червоному списку МСОП досліджувані види віднесено до 6 категорій раритетності; з них переважає група таксонів з низьким рівнем ризику зникнення (82,9 % видів). До групи під загрозою зникнення (категорії CR, EN, VU) входить 20 видів. До Європейського Червоного списку внесено 9 із досліджуваних видів. 7 видів внесено до Червоної книги України (2009), а Syringa josіkaea – також до Додатку І Бернської конвенції. Показано, що в умовах ботанічного саду Чернівецького національного університету 174 із досліджуваних дендросозофітів формують життєздатне насіння, а у 42 із них відзначено самосів. Виявлено, що 192 види повністю пристосувалися до умов культивування і мають найвищий ступінь акліматизації (І). Виділено види, які в Чернівецькій області стали інвазійними (Robinia pseudoacacia L., Acer negundo L., Quercus rubra L.), а також типові для Буковини види; всі вони мають категорію LC у Червоному списку МСОП. Успішна акліматизація та здатність до насіннєвого розмноження більшості видів свідчать про те, що колекційні фонди ботанічного саду Чернівецького національного університету є потенціалом для ефективного збереження дендросозофітів ex-situ

Facilities for the Energy Frontier of Nuclear Physics

The Relativistic Heavy Ion Collider at BNL has been exploring the energy frontier of nuclear physics since 2001. Its performance, flexibility and continued innovative upgrading can sustain its physics output for years to come. Now, the Large Hadron Collider at CERN is about to extend the frontier energy of laboratory nuclear collisions by more than an order of magnitude. In the coming years, its physics reach will evolve towards still higher energy, luminosity and varying collision species, within performance bounds set by accelerator technology and by nuclear physics itself. Complementary high-energy facilities will include fixed-target collisions at the CERN SPS, the FAIR complex at GSI and possible electron-ion colliders based on CEBAF at JLAB, RHIC at BNL or the LHC at CERN.Comment: Invited talk at the International Nuclear Physics Conference, Vancouver, Canada, 4-9 July 2010, to be published in Journal of Physics: Conference Series. http://inpc2010.triumf.ca

Methodology for determining the parameters of drilling mode for directional straight sections of well using screw downhole motors

Article presents results of study on possibility of increasing the efficiency of drilling directional straight sections of wells using screw downhole motors (SDM) with a combined method of drilling with rotation of drilling string (DS). Goal is to ensure steady-state operation of SDM with simultaneous rotation of DS by reducing the amplitude of oscillations with adjusting the parameters of drilling mode on the basis of mathematical modeling for SDM – DS system. Results of experimental study on determination of extrema distribution of lateral and axial oscillations of SDM frame depending on geometrical parameters of gerotor mechanism and modes ensuring stable operation are presented. Approaches to development of a mathematical model and methodology are conceptually outlined that allow determining the range of self-oscillations for SDM – DS system and boundaries of rotational and translational wave perturbations for a heterogeneous rod with an installed SDM at drilling directional straight sections of well. This mathematical model of SDM – DS system's dynamics makes it possible to predict optimal parameters of directional drilling mode that ensure stable operation of borehole assembly

JUSTIFICATION OF THE TECHNOLOGICAL PARAMETERS CHOICE FOR WELL DRILLING BY ROTARY STEERABLE SYSTEMS

Paper presents the analysis of the investigation results of vibrational accelerations and beating amplitudes of the downhole drilling motor, which help to define the ranges of optimum energy characteristics of the gerotor mechanism, ensuring its stable operation. Dependencies describing the operation of the «drilling bit – rotary steerable system with power screw section – drilling string» system and the values of the self-oscillation boundaries and the onset of system resonance when it is used jointly, were defined as a result of computational and full-scale experimental research. A mathematical model is proposed, which allows determining the optimal range of technological parameters for well drilling, reducing the extreme vibration accelerations of the bottomhole assembly by controlling the torque-power and frequency characteristics of the drilling string, taking into account the energy characteristics of the power screw section of the rotary steerable system. Recommendations on the choice of drilling mode parameters were given

Charge and matter distributions and form factors of light, medium and heavy neutron-rich nuclei

Results of charge form factors calculations for several unstable neutron-rich isotopes of light, medium and heavy nuclei (He, Li, Ni, Kr, Sn) are presented and compared to those of stable isotopes in the same isotopic chain. For the lighter isotopes (He and Li) the proton and neutron densities are obtained within a microscopic large-scale shell-model, while for heavier ones Ni, Kr and Sn the densities are calculated in deformed self-consistent mean-field Skyrme HF+BCS method. We also compare proton densities to matter densities together with their rms radii and diffuseness parameter values. Whenever possible comparison of form factors, densities and rms radii with available experimental data is also performed. Calculations of form factors are carried out both in plane wave Born approximation (PWBA) and in distorted wave Born approximation (DWBA). These form factors are suggested as predictions for the future experiments on the electron-radioactive beam colliders where the effect of the neutron halo or skin on the proton distributions in exotic nuclei is planned to be studied and thereby the various theoretical models of exotic nuclei will be tested.Comment: 26 pages, 11 figures, 3 tables, accepted for publication in Phys. Rev.

Avaliação dos aspectos financeiros das pequenas e médias empresas: experiência russa

The aim of this study was to assess the key financials of an array of micro-sized businesses, small and medium-sized enterprises as grouped by industry. This article deals with the assessment results of such financials as the net financial result of enterprises, the proportion of profitable and loss-making enterprises, the profitability of manufactured and sold products, the current levels of profit and loss, respectively, per profitable and loss-making enterprise. The dynamics of such financials during the period from 2010 to 2014 was presented. Accounting and statistical reporting was used as the input data. In the course of this research it was proven that during that period the profitable enterprises accounted for about 80%. However, the level of profitability did not depend on the size of an enterprise. The largest proportion of profitable enterprises was noted in such sectors as education and commerce. The net financial result per employee in micro-enterprises was significantly higher than those for medium-sized enterprises and small enterprises. The results of this study may be used to validate business development plans and programs for various regions and sectors of the Russian economy. El objetivo de este estudio fue evaluar las finanzas clave de una serie de pequeñas empresas, pequeñas y medianas empresas agrupadas por industria. Este artículo trata de los resultados de la evaluación de tales finanzas como el resultado financiero neto de las empresas, la proporción de empresas rentables y que generan pérdidas, la rentabilidad de los productos fabricados y vendidos, los niveles actuales de ganancias y pérdidas, respectivamente, por rentabilidad y pérdida empresa de creación. La dinámica de tales finanzas durante el período 2010-2014 se presentó. Los informes contables y estadísticos se usaron como datos de entrada. En el curso de esta investigación, se comprobó que durante ese período las empresas rentables representaron aproximadamente el 80%. Sin embargo, el nivel de rentabilidad no depende del tamaño de una empresa. La mayor proporción de empresas rentables se observó en sectores como la educación y el comercio. El resultado financiero neto por empleado en las microempresas fue significativamente mayor que el de las medianas y pequeñas empresas. Los resultados de este estudio pueden usarse para validar planes y programas de desarrollo comercial para diversas regiones y sectores de la economía rusa. O objetivo deste estudo foi avaliar as principais finanças de uma série de microempresas, pequenas e médias empresas agrupadas por setor. Este artigo trata dos resultados da avaliação de tais finanças como o resultado financeiro líquido das empresas, a proporção de empresas lucrativas e deficitárias, a rentabilidade dos produtos fabricados e vendidos, os níveis atuais de lucros e perdas, respectivamente, por lucro e perda empresa de fabricação. A dinâmica de tais finanças durante o período de 2010 a 2014 foi apresentada. Relatórios contábeis e estatísticos foram usados como dados de entrada. No decorrer desta pesquisa, ficou provado que, durante esse período, as empresas lucrativas representavam cerca de 80%. No entanto, o nível de lucratividade não dependia do tamanho de uma empresa. A maior proporção de empresas lucrativas foi observada em setores como educação e comércio. O resultado financeiro líquido por empregado nas microempresas foi significativamente superior ao das médias empresas e pequenas empresas. Os resultados deste estudo podem ser usados para validar planos e programas de desenvolvimento de negócios para várias regiões e setores da economia russa

Acesso das pequenas empresas russas aos mercados de contratos públicos: análise de dados

The aim of this study was to assess the current extent of participation by Russian small enterprises in regional public procurement. We discussed how legislation affects the volume of contracts awarded to small enterprises. We calculated the number of contracts per 100 small enterprises, how much the number and value of such contracts account for in the total number and value of contracts concluded with all suppliers per region, as well as what is the average value of contracts per small enterprise and the average value of one such contract. In order to ensure benchmarking for enterprises located in different regions, such enterprises were assessed on the basis of relative indicators. This study used official statistics accumulated with regard to all public procurement in the regions. The data on the number of contracts and their value for the period from 2010 to 2014 were used. For the purposes of empirical data analysis, the normal distribution probability density functions set for all the indicators in question were used. The findings of this study and the tools used for assessing the extent of participation by small enterprises in public procurement can be used when researching entrepreneurship, as well as to justify the contract system development programs in Russia. Such information is important for entrepreneurs, as it enables them to assess the feasibility and consequences of participation in public procurement.El objetivo de este estudio fue evaluar el grado actual de participación de las pequeñas empresas rusas en la contratación pública regional. Discutimos cómo la legislación afecta el volumen de contratos adjudicados a pequeñas empresas. Calculamos el número de contratos por cada 100 pequeñas empresas, cuánto representan el número y el valor de dichos contratos en el número y el valor total de los contratos celebrados con todos los proveedores por región, así como también cuál es el valor promedio de los contratos por cada pequeña empresa y el valor promedio de uno de esos contratos. Con el fin de garantizar la evaluación comparativa para las empresas ubicadas en diferentes regiones, dichas empresas se evaluaron sobre la base de indicadores relativos. Este estudio utilizó estadísticas oficiales acumuladas con respecto a todas las contrataciones públicas en las regiones. Se utilizaron los datos sobre el número de contratos y su valor para el período de 2010 a 2014. A los efectos del análisis de datos empíricos, se utilizaron las funciones de densidad de probabilidad de distribución normal establecidas para todos los indicadores en cuestión. Las conclusiones de este estudio y las herramientas utilizadas para evaluar el grado de participación de las pequeñas empresas en la contratación pública se pueden utilizar al investigar el espíritu empresarial, así como para justificar los programas de desarrollo de sistemas contractuales en Rusia. Dicha información es importante para los empresarios, ya que les permite evaluar la viabilidad y las consecuencias de la participación en la contratación pública.O objetivo deste estudo foi avaliar o atual grau de participação das pequenas empresas russas nas compras públicas regionais. Discutimos como a legislação afeta o volume de contratos concedidos a pequenas empresas. Nós calculamos o número de contratos por 100 pequenas empresas, que representam o número eo valor desses contratos no número total eo valor total dos contratos com todos os fornecedores por região, bem como o que o valor médio de contratos para cada empresa de pequeno porte e o valor médio de um desses contratos. Para garantir benchmarking para empresas localizadas em diferentes regiões, essas empresas foram avaliadas com base em indicadores relativos. Este estudo utilizou estatísticas oficiais acumuladas em relação a todas as compras públicas nas regiões. Foram utilizados os dados sobre o número de contratos e seu valor para o período de 2010 a 2014. Para fins de análise empírica dos dados, foram utilizadas as funções de densidade de probabilidade de distribuição normal estabelecidas para todos os indicadores em questão. As conclusões deste estudo e os instrumentos utilizados para avaliar o grau de participação das pequenas empresas nos contratos públicos podem ser utilizados na investigação do empreendedorismo, bem como para justificar os programas de desenvolvimento de sistemas contratuais na Rússia. Esta informação é importante para os empresários, pois permite avaliar a viabilidade e as consequências da participação em contratos públicos

PosterVote:expanding the action repertoire for local political activism

Online and digital technologies support and extend the action repertoires of localized social movements. In this paper we examine the ways by which digital technologies can support ‘on-the-ground ’ activist communities in the development of social movements. After identifying some of the challenges of deploying conventional voting and consultation technologies for activism, we examine situated political action in local communities through the design and deployment of a low-cost community voting prototype, PosterVote. We deploy PosterVote in two case studies with two local community organizations identifying the features that supported or hindered grassroots democratic practices. Through interviews with these communities, we explore the design of situated voting systems to support grassroots democratic practices and participation within an ecology of social action. Author Keywords Democracy; activism; participation; e-votin