Accretion by Isolated Neutron Stars

Accretion of interstellar material by an isolated neutron star is discussed. The point I address here is the interaction between the accretion flow and the stellar magnetosphere. I show that the interchange instabilities of the magnetospheric boundary under the conditions of interest are basically suppressed. The entry of the material into the magnetosphere is governed by diffusion. Due to this reason the persistent accretion luminosity of isolated neutron stars is limited to < 4E+26 erg/s. These objects can also appear as X-ray bursters with the burst durations of about 30 minutes and repetition time of about 1E+5 yr. This indicates that the number of the accreting isolated neutron stars which could be observed with recent and modern X-ray missions is a few orders of magnitude smaller than that previously estimated.Comment: 3 pages, to appear in Astrophysics and Space Science, in the proceedings of "Isolated Neutron Stars: from the Interior to the Surface", edited by D. Page, R. Turolla and S. Zan

Big Data incorporation based on Open Services Provider for distributed enterprises

There is provided a new software solution for multiple data sources integration at modern enterprises with distributed organizational structure. Open Services Provider (OSP) is a platform powered by SEC "Open code" that allows developing situational centers for decision making support based on Big Data analysis and visualization. The paper describes a problem of management of modern distributed enterprises, the proposed OSP solution and results of its probation in practice. Research is supported by Big Data engineering center at Samara University.This work was partially supported by the Ministry of education and science of the Russian Federation in the framework of the implementation of the Program of increasing the competitiveness of SSAU among the world’s leading scientific and educational centers for 2013-2020 years; by the Russian Foundation for Basic Research grants (# 15-29- 03823, # 15-29- 07077, # 16-41- 630761; # 16-29- 11698); by the ONIT RAS program # 6 “Bioinformatics, modern information technologies and mathematical methods in medicine” 2017

Ecological monitoring in the region of Akademik Vernadsky Antarctic station

The issues of organization and carrying out of ecological monitoring in the region of the Ukrainian Antarctic Station “Akademik Vernadsky” are taken up in the report. The information about the basic circulation flows, temporal (daily and annual) and spatial changeability of hydrological & hydrochemical ingredients as well as the vertical hydrological & hydrochemical water structure are presented on the basis of 1997-1998 experimental data. The description of the modern state of the chemical pollution of the basic elements of the Argentina Archipelago Islands` shallow water ecosystem. The broad spectrum of pollutants, such as different components of oil pollution, including carcinogenic polyaromatic hydrocarbons, highly toxic chlorinated hydrocarbons, heavy metals have been found in the majority of the ecosystem`s elements under analysis. The local areas of oil pollution have been found in the region of Galindez Isles. The obtained results are the part of the experimental data base for solving fundamental and applied problems including the problem of environmental protection. It is necessary to continue such investigations for studying the tendencies, for forecasting the vulnerable Antarctic ecosystems` state and for working up measures to protect ecosystems from the further pollution.У доповіді розглянуті питання організації і виконання екологічного моніторингу в районі української антарктичної станції Академік Вернадський. На основі експериментальних даних 1997-1998 рр. представлені дані про основні циркуляційні потоки, тимчасову (добову, міжрічну) і просторову мінливість гідролого-гідрохімічних інгредієнтів, вертикальну гідролого-гідрохімічну структуру вод. Наведено характеристику сучасного стану хімічного забруднення основних елементів екосистеми шхерного мілководдя. У більшості аналізованих елементів екосистеми виявлений широкий спектр забруднюючих речовин: різні компоненти нафтового забруднення, включаючи канцерогенні поліароматичні вуглеводні, високотоксичні хлоровані вуглеводні, важкі метали. Виявлено локальні ділянки нафтового забруднення в районі острова Галіндез. Отримані результати є частиною експериментальної бази даних для рішення фундаментальних і прикладних, у тому числі природоохоронних задач. Продовження цих досліджень необхідно для вивчення тенденцій, прогнозування стану уразливих антарктичних екосистем і розробки заходів щодо запобігання їхнього подальшого забруднення

Биологические средства защиты растений в борьбе с фитопаразитическими нематодами, другими патогенами и перспективы их использования в XXI веке

Different strains of antagonistic bacteria and fungi have been actively tested for the last several years in order to discover their complex fungicidal, bactericidal and nematicidal activity in different plant communities and regions of Russia. This work is targeted for elaboration of environmentally friendly and energy-saving methods of plant protection. Bacterial strains of Pseudomonas and Bacillus, that possess not only fungicidal but also bactericidal and nematicidal effects, were revealed in the results of pot, laboratory and field experiments. These strains could regulate the number of virus-vector nematodes of Longidoridae and Trichodoridae and their associated viruses. Also, the strains could be shown to stimulate plant growth and high yield of different varieties of test-plants. They should be considered to be the natural regulators of the quantity and the distribution of parasites. This work was supported by grant RFFI 05-04-49237.С целью разработки экологически безопасных и энергосберегающих способов защиты растений в последние годы интенсивно изучаются коллекции штаммов бактерий и грибов-антагонистов, обладающих комплексной фунгицидной, бактерицидной и нематицидной активностью. Проводится их поиск в различных фитоценозах и регионах России. В результате лабораторных, вегетационных и полевых исследований впервые выделены штаммы бактерий из родов Pseudomonas и Bacillus, обладающие не только фунгицидным, бактерицидным и нематицидным эффектами, регулирующими численность нематод-вирусоносителей, но и антивирусным действием, включая вирусы, переносимые нематодами-лонгидоридами и триходоридами. Выделенные штаммы обладают стимулирующим действием на рост, вегетативную продуктивность и урожай различных видов тест-растений. Они могут рассматриваться в качестве природных регуляторов, снижающих численность и распространение в различных почвенных биоценозах нематод-вирусоносителей

ANALYSIS ОF THE 3D STRUCTURE ОF MICRO IRREGULARITY ON THE SURFACE OF THE MACHINE-BUILDING DETAIL

The operational properties of the parts depend on the roughness of its surface. The technological impact can control the structure of surface microroughness. The necessary structure of roughness can be broken by inclusions of different nature (carbides, impurities, phases). We offer a digital filer for image processing of a rough surface. The advantage of the filter is the selection of the microroughness structure on the image without inclusions. The cleaned image allows to predict the operational properties of the surface

Measuring proper motions of isolated neutron stars with Chandra

The excellent spatial resolution of the Chandra observatory offers the unprecedented possibility to measure proper motions at X-ray wavelength with relatively high accuracy using as reference the background of extragalactic or remote galactic X-ray sources. We took advantage of this capability to constrain the proper motion of RX J0806.4-4123 and RX J0420.0-5022, two X-ray bright and radio quiet isolated neutron stars (INSs) discovered by ROSAT and lacking an optical counterpart. In this paper, we present results from a preliminary analysis from which we derive 2 sigma upper limits of 76 mas/yr and 138 mas/yr on the proper motions of RX J0806.4-4123 and RX J0420.0-5022 respectively. We use these values together with those of other ROSAT discovered INSs to constrain the origin, distance and evolutionary status of this particular group of objects. We find that the tangential velocities of radio quiet ROSAT neutron stars are probably consistent with those of 'normal' pulsars. Their distribution on the sky and, for those having accurate proper motion vectors, their possible birth places, all point to a local population, probably created in the part of the Gould Belt nearest to the earth.Comment: 8 pages, 3 figures, to appear in Astrophysics and Space Science, in the proceedings of "Isolated Neutron Stars: from the Interior to the Surface", edited by D. Page, R. Turolla and S. Zan

Photoluminescence from an individual double-walled carbon nanotube

We report direct and unambiguous evidence of the existence of inner semiconducting tube (ISCT) photoluminescence (PL) from measurements performed on four individual freestanding index-identified double-walled carbon nanotubes (DWNTs). Based on thorough Rayleigh scattering, Raman scattering, and PL experiments, we are able to demonstrate that the ISCT PL is observed with a quantum yield estimated to be a few 10-6 independent of the semiconducting or metallic nature of the outer tube. This result is mainly attributed to ultrafast exciton transfer from the inner to outer tube. Furthermore, by carrying out PL excitation experiments on the (14, 1)@(15, 12) DWNT, we show that the ISCT PL can be detected through the optical excitation of the outer tube, indicating that the exciton transfer can also occur in the opposite way

Recognition of wavefront aberrations types corresponding to single Zernike functions from the pattern of the point spread function in the focal plane using neural networks

В работе осуществлено обучение и распознавание типов аберраций, соответствующих отдельным функциям Цернике, по картине интенсивности функции рассеяния точки с применением свёрточных нейронных сетей. Картины интенсивности функции рассеяния точки в фокальной плоскости моделировались с применением алгоритма быстрого преобразования Фурье. При обучении нейронной сети коэффициент обучения и количество эпох для датасета заданного размера был подобран эмпирически. Средние ошибки предсказания нейронной сети для каждого типа аберраций были получены для набора из 15 функций Цернике по датасету из 15 тысяч картин функции рассеяния точки. В результате обучения для большинства типов аберраций получены усреднённые абсолютные погрешности в диапазоне 0,012 – 0,015, однако определение коэффициента (величины) аберрации требует дополнительных исследований и данных, например, расчёта функции рассеяния точки во внефокальной плоскости. In this work, we carried out training and recognition of the types of aberrations corresponding to single Zernike functions, based on the intensity pattern of the point spread function (PSF) using convolutional neural networks. PSF intensity patterns in the focal plane were modeled using a fast Fourier transform algorithm. When training a neural network, the learning coefficient and the number of epochs for a dataset of a given size were selected empirically. The average prediction errors of the neural network for each type of aberration were obtained for a set of 15 Zernike functions from a data set of 15 thousand PSF pictures. As a result of training, for most types of aberrations, averaged absolute errors were obtained in the range of 0.012 – 0.015. However, determining the aberration coefficient (magnitude) requires additional research and data, for example, calculating the PSF in the extrafocal plane.Исследование выполнено при финансовой поддержке РФФИ в рамках научного проекта № 19-29-09054 в части, касающейся машинного обучения и нейронных сетей, а также Министерства науки и высшего образования РФ в рамках выполнения работ по Государственному заданию ФНИЦ «Кристаллография и фотоника» РАН (соглашение № 007-ГЗ/Ч3363/26) в части моделирования аберрированного волнового фронта и расчёта ФРТ

Chandra Smells a RRAT: X-ray Detection of a Rotating Radio Transient

"Rotating RAdio Transients" (RRATs) are a newly discovered astronomical phenomenon, characterised by occasional brief radio bursts, with average intervals between bursts ranging from minutes to hours. The burst spacings allow identification of periodicities, which fall in the range 0.4 to 7 seconds. The RRATs thus seem to be rotating neutron stars, albeit with properties very different from the rest of the population. We here present the serendipitous detection with the Chandra X-ray Observatory of a bright point-like X-ray source coincident with one of the RRATs. We discuss the temporal and spectral properties of this X-ray emission, consider counterparts in other wavebands, and interpret these results in the context of possible explanations for the RRAT population.Comment: 5 pages, 2 b/w figures, 1 color figure. To appear in the proceedings of "Isolated Neutron Stars", Astrophysics & Space Science, in pres