202 research outputs found
Cooling rates of neutron stars and the young neutron star in the Cassiopeia A supernova remnant
No full textWe explore the thermal state of the neutron star in the Cassiopeia A supernova remnant using the recent result of Ho & Heinke that the thermal radiation of this star is well described by a carbon atmosphere model and the emission comes from the entire stellar surface. Starting from neutron star cooling theory, we formulate a robust method to extract neutrino cooling rates of thermally relaxed stars at the neutrino cooling stage from observations of thermal surface radiation. We show how to compare these rates with the rates of standard candles – stars with non-superfluid nucleon cores cooling slowly via the modified Urca process. We find that the internal temperature of standard candles is a well-defined function of the stellar compactness parameter x=rg/R, irrespective of the equation of state of neutron star matter (R and rg are circumferential and gravitational radii, respectively). We demonstrate that the data on the Cassiopeia A neutron star can be explained in terms of three parameters: f?, the neutrino cooling efficiency with respect to the standard candle; the compactness x; and the amount of light elements in the heat-blanketing envelope. For an ordinary (iron) heat-blanketing envelope or a low-mass (? 10?13 M?) carbon envelope, we find the efficiency f?? 1 (standard cooling) for x? 0.5 and f?? 0.02 (slower cooling) for a maximum compactness x? 0.7. A heat blanket containing the maximum mass (?10?8 M?) of light elements increases f? by a factor of 50. We also examine the (unlikely) possibility that the star is still thermally non-relaxe
Azygophleps junkeri Yakovlev & Witt 2017, sp. nov.
No full textAzygophleps junkeri Yakovlev & Witt, sp. nov. (Figs 6 ¯7, 15¯16) Material. Holotype: ♂, Angola, prov. Benguela, btw Cutembo & Caluquembe, 14 km E Cutembo, 13°46.901’ S 14°00.105’ E, 965 m, 2.iv.2014, leg. Naumann, Sulak & Ott (GenPr MWM: 26759; MWM). 2 ♂, same data (MWM); 3 ♂, Angola, Prov. Huambo, 2 km S Calanque, 12°52.214’ S 15°28.126’E, 1970 m, 27.iii.2014, leg. Sulak, Naumann & Ott (MWM); 2 ♂, Dzalanyama forest, Lilongwe distr., C. Malawi, 1300 m, 21.iv.2006, leg. R. Murphy (RMM); 2 ♂, Ntchisi forest, C. Malawi, 1600 m, 10.–17.v.2002, leg. R. Murphy (RMM); 1 ♂, C. Malawi, Kasungu N.P., Lifupa Lodge, 13°05'12"S 33°08'17"E, 1035 m, 22.iv.2011, leg. R. Yakovlev (RYB); 47 ♂, [Congo], Elisabethville, different data (1933¯1959), leg. Ch. Seydel (MRAC); 2 ♂, Burundi, Gitega, 20.v.1965, Dr. M. Fontaine (MRAC); 2 ♂, [Congo], Katanga, Zilo, iii.1968, Rec. V. Allard (MRAC); 1 ♂, [Congo], Zaire, Lubumbashi, 16.iii.1979, Th. Bouyer (MRAC); 1 ♂, South West Africa [Namibia], Mashare, c. 17°54’S 20°09’E, 12.iii.1978, leg. J. Ball (TMSA); 2 ♂, Tanzania, Rukwa Province, Mbizi Mts., entre Kisungu et Muze, 1415 m, 07°43.826’ S 031°32.482’ E, 14.05.2004, leg. Ph. Darge (MWM); 2 ♂, Tanzania, Rukwa Province, Kisengere / Kasimbo, 1193 m, 07°27.540' S 03°52.812' E, 17.05.2004, leg. Ph. Darge (MWM). Description. Length of forewing of holotype 21 mm (in male paratypes 19¯ 23 mm). Antenna bipectinate in proximal half, filiform in distal half. Thorax, tegula, patagia and abdomen brown. Fore wing brown with pattern of tiny fine black transverse strokes spaced rather evenly throughout the surface of the wing, narrow white area on costal edge from base to apex of wing. Hind wing brown with imperceptible pattern of fine transverse strokes, more expressed in cubital area. Anal edge pale, without pattern. Fringe pale brown, unicolorous. Male genitalia. Uncus long, triangle, with tapered uncinate apex; gnathos arms of medium thickness, ribbonlike, tapered to apices, not fused; valva simple, leaf-like, with even costal edge, obliquely cut outer edge and small notch in proximal third of abdominal edge; juxta large with narrow slit notch on dorsal surface and two long (in length equal to 2/5 of valva) lateral processes of medium thickness, directed dorsally; saccus small, semicircular; phallus thick, slightly shorter than valva, in vesica two ribbon-like sclerites in lateral surfaces, one of them two times larger and longer than the other. Female unknown. Diagnosis. The new species was erroneously determined several times by the senior author as A. aburae (Plötz, 1880) (type locality Bei Aburi [Ghana]) (Yakovlev 2011; Yakovlev & Murphy 2013; Yakovlev & Witt 2016a). The error in definition was first indicated by W. Mey (2016: 168): “The type material of A. aburae (Plötz, 1880) has not been traced so far and is probably lost. According to the original description of the species (unfortunately without illustrations), it should have an external appearance which comes close to a small individual of A. atrifasciata Hampson, 1910. The specimens identified and photographed by Yakovlev [& Murphy] (2013) as A. aburae neither correspond to the description given by Plötz (1880) nor to the colour figure in Gaede (1930). His specimens together with the present individual belong to a different species with unknown affiliation”. The new species differs well from all the known species of this genus by the following features: rather dark colour of the wings, pale narrow portion in the costal area of the forewing, two ribbon-like sclerites in the vesica, very long lateral processes of the juxta, narrow slit-shaped notch on the dorsal surface of the juxta. Distribution. Central and southern Africa: Congo, Burundi, Tanzania, Malawi, Angola and Namibia. Etymology. The new species is named after Wilhelm Junker (1840¯1892), doctor of medicine, Russian geographer and traveler, who studied the watershed of Nile and Congo, made a number of geographical discoveries, compiled the dictionary of ten ethnic groups in southeastern Africa, and gathered rich ethnographic, zoological, and botanical collections.Published as part of Yakovlev, Roman V. & Witt, Thomas J., 2017, Four new species of Azygophleps Hampson, 1892 (Lepidoptera, Cossidae, Zeuzerinae) from Africa, pp. 437-444 in Zootaxa 4303 (3) on pages 441-443, DOI: 10.11646/zootaxa.4303.3.9, http://zenodo.org/record/309464
Twenty Letters from St. Petersburg (epistolary heritage of A.I. Yakovlev)
No full textВ статье анализируется переписка владельца крупного уральского Верх-Исетского горного округа А. И. Яковлева с Главным заводским правлением о деятельности училища для детей служащих.Выявлены некоторые аспекты дистантных «хозяйственных распоряжений» А. И. Яковлева по учреждению и организации деятельности верхисетского заводского училища.The article is devoted to the correspondence of the owner of a large Verkh-Isetsky Ural Mining District A. I. Yakovlev main factory on the activities of the school board for the children of employees. The author points to the role of letters as a means of achieving a distant breeder its management functions. Some aspects of the distant «business orders» A. I. Yakovlev on the establishment, organization of the top-Isetsky factory school
Aleksey Yakovlev and Dmitry Ulyanov (from the Family History of Yakovlevs and Ulyanovs)
No full textThe longstanding friendship between the Yakovlev and Ulyanov families is a wide-ranging topic. The
Ulyanov family has been thoroughly studied by historians, but the Yakovlevs did not enjoy comparable attention.
The most renowned of this last clan was Alexey Ivanovich Yakovlev, who kept up relations with Vladimir Lenin. But
in the light of archival materials and memoirs, one could claim that interfamily relations extended beyond familiarity
between these two individuals. The paper traces friendship between Alexey Ivanovich Yakovlev and Dmitry Il'ich
Ulyanov. These friendly terms lasted for decades, since the childhood of the confidants, who maintained warm
relations despite the circumstances and the vicissitudes of their fates. The source for the study of their friendship
is the correspondence between them. A number of letters from both have been published, and the rest are in the
Archive of the FSB Directorate of St. Petersburg and the Leningrad Region, in the investigative file of A. I. Yakovlev,
who was arrested during the “Academic Case” of 1929–1931. The correspondence between Dmitry Ulyanov
and Alexei Yakovlev began in 1893. Despite all the differences in their professional activity in the following years,
their friendship continued even after the Revolution, when A. I. Yakovlev became a famous historian, author of
several monographs, and a professor at Moscow University, and Dmitry Ulyanov held a number of high government
positions, including the head of the government of the Soviet Crimea. The last letter of their many years of
correspondence is dated 1943
Growth of nanoparticles in liquid medium using magnetron sputtering technique
No full textTitle: Growth of nanoparticles in liquid medium using magnetron sputtering technique Author: Josef Kučera Department: Department of Surface and Plasma Science Supervisor: Mgr. Yurii Yakovlev, Ph.D., Department of Surface and Plasma Science Abstract: This thesis investigates the preparation of platinum and platinum-ruthenium alloy nanoparticles using magnetron sputtering method on a liquid substrate. Polypropylene glycol with three different molecular weights of 425, 1000, and 4000 was chosen as the liquid substrate. The influence of the different viscosities of these substrates on the size and morphology of the nanoparticles produced in the magnetron was investigated. Dynamic light scattering and transmission electron microscopy methods were used to determine the size of the nanoparticles. Furthermore, the catalytic activity of the produced nanoparticles in an alkaline environment was investigated using the rotating disk electrode technique. Keywords: Nanoparticles, Magnetron Sputtering, Polypropylene glycol, Hydrogen Fuel Cells, Water Electrolyzers, Hydrogen oxidation/reduction reactions
Growth of nanoparticles in liquid medium using magnetron sputtering technique
No full textNázev práce: Růst nanočástic v kapalném prostředí technikou magnetronového naprašování Autor: Josef Kučera Katedra / Ústav: Katedra fyziky povrchů a plazmatu Vedoucí bakalářské práce: Mgr. Yurii Yakovlev, Ph.D., Katedra fyziky povrchů a plazmatu Abstrakt: Tato práce zkoumá přípravu nanočástic platiny a platino-rutheniové slitiny pomocí metody magnetronového naprašování na kapalný substrát. Jako použitý kapalný substrát byl zvolen polypropylenglykol se třemi různými molekulárními hmotnostmi 425, 1000 a 4000. U těchto substrátů bylo prozkoumáno, jak jejich rozdílná viskosita ovlivňuje velikost a morfologii nanočástic připravených v magnetronu. Pro určení velikosti nanočástic byly využity metody dynamického rozptylu světla a transmisní elektronové mikroskopie. Dále byla prozkoumána katalytická aktivita vytvořených nanočástic v alkalickém prostředí pomocí techniky rotační diskové elektrody. Klíčová slova: Nanočástice, magnetronové naprašování, polypropylenglykol, vodíkové palivové články, elektrolyzéry vody, vodíkové redoxní reakce.Title: Growth of nanoparticles in liquid medium using magnetron sputtering technique Author: Josef Kučera Department: Department of Surface and Plasma Science Supervisor: Mgr. Yurii Yakovlev, Ph.D., Department of Surface and Plasma Science Abstract: This thesis investigates the preparation of platinum and platinum-ruthenium alloy nanoparticles using magnetron sputtering method on a liquid substrate. Polypropylene glycol with three different molecular weights of 425, 1000, and 4000 was chosen as the liquid substrate. The influence of the different viscosities of these substrates on the size and morphology of the nanoparticles produced in the magnetron was investigated. Dynamic light scattering and transmission electron microscopy methods were used to determine the size of the nanoparticles. Furthermore, the catalytic activity of the produced nanoparticles in an alkaline environment was investigated using the rotating disk electrode technique. Keywords: Nanoparticles, Magnetron Sputtering, Polypropylene glycol, Hydrogen Fuel Cells, Water Electrolyzers, Hydrogen oxidation/reduction reactions.Department of Surface and Plasma ScienceKatedra fyziky povrchů a plazmatuMatematicko-fyzikální fakultaFaculty of Mathematics and Physic
Optimization of the performance of fuel cell stacks using an ultrasonic humidifier.
No full textTitle: Optimization of the Performance of Fuel Cell Stacks Using an Ultrasonic Humidi- fier. Author: Martin Vaněk Department: Department of Surface and Plasma Science Supervisor: Mgr. Yurii Yakovlev, Ph.D., Department of Surface and Plasma Science Abstract: This work is concerned with the optimization of the performance of PEM hydrogen fuel cell stacks, a technology that opens up new possibilities for clean energy storage and restoration. We have hand-built a PEMFC open-cathode stack of 20 cells and measured its basic characteristics such as the j-V and j-P curves as well as the dependency of the temperature of the stack on power produced by the stack for constant power of the cooling fans. We have implemented and tested the performance of a new method for water and thermal management - the humidification of air via the use of an ultrasonic water fog generator. Several tests - measuring cooling efficiency, voltage variations between different cells, and j-V and j-P curves - were performed under different temperatures and with or without humidification. Keywords: fuel cell, self humidification, open cathode, performance
Optimalizace svazků palivových článků pomocí ultrazvukového zvlhčovače.
No full textTitle: Optimization of the Performance of Fuel Cell Stacks Using an Ultrasonic Humidi- fier. Author: Martin Vaněk Department: Department of Surface and Plasma Science Supervisor: Mgr. Yurii Yakovlev, Ph.D., Department of Surface and Plasma Science Abstract: This work is concerned with the optimization of the performance of PEM hydrogen fuel cell stacks, a technology that opens up new possibilities for clean energy storage and restoration. We have hand-built a PEMFC open-cathode stack of 20 cells and measured its basic characteristics such as the j-V and j-P curves as well as the dependency of the temperature of the stack on power produced by the stack for constant power of the cooling fans. We have implemented and tested the performance of a new method for water and thermal management - the humidification of air via the use of an ultrasonic water fog generator. Several tests - measuring cooling efficiency, voltage variations between different cells, and j-V and j-P curves - were performed under different temperatures and with or without humidification. Keywords: fuel cell, self humidification, open cathode, performance 1Název práce: Optimalizace svazků palivových článků pomocí ultrazvukového zvlhčovače. Autor: Martin Vaněk Katedra: Katedra fyziky povrchů a plazmatu Vedoucí bakalářské práce: Mgr. Yurii Yakovlev, Ph.D., Katedra fyziky povrchů a plaz- matu Abstrakt: Tato práce se zabývá optimalizací výkonu svazků PEM palivových článků, technologie, která otevírá nové možnosti pro uskladnění a zpětnou výrobu elektrické energie. Sestavili jsme dvaceticelový sériový svazek PEM vodíkových palivových článků s otevřenou katodou a změřili jeho základní charakteristiky, jako jsou j-V a j-P křivky a také závislost teploty článku na výkonu, který produkuje za konstantního výkonu chladících větráků. Implementovali a otestovali jsme novou metodu pro správu vody a teploty článku - zvlhčování příchozího vzduchu pomocí ultrazvukového generátoru mlhy - a její vliv na výkon svazku. Provedli jsme několik testů - měření efektivity chlazení, variací v napětích na jednotlivých celách a j-V a j-V křivky - a to za různých podmínek, konkrétně při různých teplotách a se zvlhčováním či bez něj. Klíčová slova: palivový článek, samozvlhčování, otevřená katoda, výkon 1Department of Surface and Plasma ScienceKatedra fyziky povrchů a plazmatuMatematicko-fyzikální fakultaFaculty of Mathematics and Physic
Topical Structure of Chelyabinsk Local Encyclopedic Text (Based on the Entries About Personalities)
No full textЯковлев Дмитрий Иванович, аспирант кафедры лингвистики и перевода, Южно-Уральский государственный университет (Челябинск), [email protected]. Научный руководитель – доктор филологических наук, профессор Т.Н. Хомутова. Dmitriy I. Yakovlev, Postgraduate Student, Department of Linguistics and Translation, South-Ural State
University (Chelyabinsk), [email protected]. Scientific Advisor – Doctor of Philology, Prof. T.N. Khomutova.Рассматривается тематическая структура челябинского локального энциклопедического текста на материале текстов о персоналиях. Описывается процедура отбора текстов для анализа тематической структуры и составления списка тематических областей, проводится детальный анализ тематической структуры, рассматриваются перспективы дальнейшего исследования. The paper focuses on the analysis of the topical structure of Chelyabinsk local encyclopedic text.
The author describes the procedure of selecting texts for the analysis and making a list of topics, analyses
the topical structure, as well as outlines the perspectives of further research
Информационно-вычислительное обеспечение сырьевых исследований
No full textDatabases available in YugNIRO reflect main trends of resource studies and incorporate: 1) commercial biological and oceanographic data obtained as a result of expeditional studies in the Indian and Southern Oceans and in the Black Sea and kept in the Data Bank of the Information System of Subscribers' Archives (ISAA) as unified forms of collection and record of data; 2) operative data from fisheries as daily radioreports (system RIF) and daily radioreports (system OCEAN) aggregated into monthly arrays on magnetic tapes; 3) temporal series characterizing state of ecosystem obtained as a result of calculations and analysis; 4) hydrometeorological information for the areas of the Indian and Southern Oceans and for the Black Sea. Data on availability of information on machine carriers are given in the table.Исследования, направленные на изучение состояния сырьевой базы рыболовства и прогнозирование возможного вылова, требуют переработки к анализа больших объемов многоплановой информации, характеризующей как условия внешней среды, так и состояние биологических объектов различных трофических уровней. Имеющиеся в ЮгНИРО базы данных, отражающие основные направления сырьевых исследований, и специализированные программные средства, реализующие практически все используемые в рыбохозяйственных исследованиях методы и модели оценки запасов и прогнозирования возможных уловов гидробионтов, позволяют обеспечивать рыбное хозяйство республики достоверными данными о возможных уловах и расстановке флота на промысле. Информационное обеспечение включает в себя: — промыслово-биологические и океанографические данные, полученные в результате экспедиционных исследований в Индийском и Южном океанах и в Чёрном море, хранящиеся в банке данных Информационной Системы Абонентского Архива (ИСАА) в виде унифицированных форм сбора и регистрации данных; — оперативные данные с промысла в виде ССД С7 (система
РИФ) и ССД С5 (система ОКЕАН), агрегированных в помесячные массивы на МЛ; — временные ряды, характеризующие состоявшее экосистемы, полученные в результате специально проведённых расчётов и анализа; — гидрометеорологическая информация по районам Индийского и Южного океанов и по Чёрному морю.Publishe
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