72 research outputs found
Production of <sup>235</sup>Np, <sup>236</sup>Pu and <sup>237</sup>Pu via nuclear reactions on <sup>235,236,238</sup>U and <sup>237</sup>Np targets
A summary of methods for cyclotron production of 235Np (396.1d), 236Pu (2.858y) and 237Pu (45.2d) via nuclear reactions with protons and 3He-ions on 235,236,238U and 237Np targets in wide energy ranges is given. Methods for the chemical separation and purification of these nuclides from the irradiated uranium and neptunium targets are described. Cross sections, yields and radionuclidic purities of 235Np, 236Pu and 237Pu are presented and compared with literature data on the nuclear reactions leading to these radionuclides. The nuclear reactions with the so far highest known yields of 235Np, 236Pu and 237Pu are determined: 236U(p, 2n)235Np, 237Np(p, 2n + pnβ-)236Pu and 237Np(p, n) 237Pu, respectively. The highest radionuclidic purity of 235Np, 236Pu and 237Pu tracers can be reached with the 236U(p, 2n)235Np, 236U(p, nβ -)236Pu and 237Np(3He, t) 237Pu reactions, respectively. In addition new cross sections and yield data of the 236U(3He, p3n)235Np reaction in the energy range 42.4-60 MeV are given.</p
Schattenwirtschaft in Rußland: Aktivitäten legaler russischer Unternehmen
'Die Durchführung marktwirtschaftlicher Reformen in Rußland hat zu einer Ausweitung der Schattenwirtschaft (d.h. der verborgenen, informellen Wirtschaft) geführt. Das Staatskomitee für Statistik der Russischen Föderation (RF) schätzt die Größe dieses Sektors auf 20-25 Prozent des Bruttoinlandsprodukts, der Föderale Sicherheitsdienst und das Innenministerium gehen sogar von 40-50 Prozent aus. Eine Besonderheit der russischen Transformationswirtschaft ist der steile Anstieg der nicht offiziell verbuchten, vor den Steuerbehörden verborgenen Aktivitäten legaler und registrierter Firmen und Unternehmen. Steuerhinterziehung seitens der legalen Geschäftswelt macht einen großen Teil der Schattenwirtschaft aus, der von der Statistik nicht unmittelbar erfaßt werden kann. Der Bericht bietet einen firmenbezogenen Ansatz, um die qualitativen Seiten der schattenwirtschaftlichen Tätigkeit legaler Unternehmen, die nicht im finanzwirtschaftlichen Sektor, sondern in der Produktion und im Dienstleistungsgewerbe aktiv sind, zu analysieren. Er basiert auf der Auswertung von Ergebnissen empirischer Untersuchungen. Ende 1997 führte das Institut für strategische Analyse und Entwicklung des Unternehmertums (ISARP) zwei Stichprobenuntersuchungen unter 1.100 Industrieunternehmen und 2.500 Einzelhandelsunternehmen durch, die vom Zentrum für Wirtschaftskonjunktur bei der Regierung der RF ausgewählt worden waren. Ebenfalls im Zeitraum 1995-1998 wurde eine Reihe von Tiefeninterviews und Fokusgruppenbefragungen mit Unternehmern, Managern, Experten, Steuerbeamten und Bediensteten der Kommunalverwaltungen geführt.' (Textauszug)'The introduction of market-economy reforms in Russia has caused the shadow economy (i.e. the hidden, informal economy) to expand. The State Committee for Statistics of the Russian Federation (RF) estimates the Output of this sector to amount to 20-25 percent of gross domestic product, the Federal Security Service and the Interior Ministry assume a figure of 40-50 percent. A special feature of the Russian transformation economy is the sharp rise in the activities which legally established and registered companies and businesses do not officially book and which thus escape the notice of the fiscal authorities. Tax evasion by the legal business world accounts for a major part of the shadow economy, and one which can not be directly gauged via statistics. The present report proposes a company-related approach to analysing the qualitative sides of shadow-economy activity by legal enterprises that operate not in the financial sector but in production and the services sector. It is based an examination of the findings of empirical studies. In late 1997 the Institute for Strategic Analysis and Development of Enterprise (ISARP) conducted two random sample studies among 1,100 industrial businesses and 2,500 retail trading businesses selected by the Centre for Economic Conjuncture by the government of the RF. Likewise in the period 1995-1998, a series of in-depth interviews and focus groups was carried out with business owners, managers, experts, tax officials and local administration civil servants.' (extract
РОЛЬ С.П. БОТКИНА В СОЗДАНИИ И РАЗВИТИИ ПЕРВОЙ В РОССИИ ИНФЕКЦИОННОЙ БОЛЬНИЦЫ
The article presents the role of S.P. Botkin in the creation and development of Russia’s first infectious hospital. The creation of the hospital contributed to unfavorable epidemiological situation in a number of infectious diseases in St. Petersburg in 60–70 years XIX century. For the treatment of infectious diseases were no specialized infections hospital. At the initiative of S.P. Botkin was created Russia’s first hospital for infectious diseases, he also became a trustee on the medical side. Under the guidance of Professor Botkin in the barracks hospital began a systematic study of infectious diseases, there was formed the national school of infectious disease. On his initiative, the hospital created the first ambulance coach, first disinfecting chamber, opened the chemical and physiological laboratory. Sergei Petrovich in the hospital laid the foundation of the hospital medical statistics. He made a great contribution to the reorganization of the ambulance and hospital pharmacies. Opening of the Infectious Diseases Hospital has reduced he mortality rate from infectious diseases in St. Petersburg in three times.В статье освещена роль С.П. Боткина в создании и развитии первой в России инфекционной больницы. Созданию больницы способствовала неблагополучная эпидемиологическая обстановка по ряду инфекционных заболеваний в Санкт-Петербурге в 1860–1870-е гг. Для лечения инфекционных больных отсутствовали специализированные инфекционные больницы. По инициативе С.П. Боткина была создана первая в России больница для инфекционных больных, он же стал и её попечителем по врачебной части. Под руководством профессора Боткина в барачной больнице началось систематическое изучение инфекционных болезней, там была сформирована отечественная школа врачей-нфекционистов. По его инициативе в больнице была создана первая санитарная карета, первая дезинфекционная камера, открыта химико-физиологическая лаборатория. Сергей Петрович в больнице заложил основы медицинской больничной статистики. Он внес большой вклад в реорганизацию работы амбулатории и аптеки больницы. Открытие инфекционной больницы позволило снизить летальность от инфекционных болезней в Санкт-Петербурге в три раза
Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR
Substantial experimental and theoretical efforts worldwide are devoted to
explore the phase diagram of strongly interacting matter. At LHC and top RHIC
energies, QCD matter is studied at very high temperatures and nearly vanishing
net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was
created at experiments at RHIC and LHC. The transition from the QGP back to the
hadron gas is found to be a smooth cross over. For larger net-baryon densities
and lower temperatures, it is expected that the QCD phase diagram exhibits a
rich structure, such as a first-order phase transition between hadronic and
partonic matter which terminates in a critical point, or exotic phases like
quarkyonic matter. The discovery of these landmarks would be a breakthrough in
our understanding of the strong interaction and is therefore in the focus of
various high-energy heavy-ion research programs. The Compressed Baryonic Matter
(CBM) experiment at FAIR will play a unique role in the exploration of the QCD
phase diagram in the region of high net-baryon densities, because it is
designed to run at unprecedented interaction rates. High-rate operation is the
key prerequisite for high-precision measurements of multi-differential
observables and of rare diagnostic probes which are sensitive to the dense
phase of the nuclear fireball. The goal of the CBM experiment at SIS100
(sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD
matter: the phase structure at large baryon-chemical potentials (mu_B > 500
MeV), effects of chiral symmetry, and the equation-of-state at high density as
it is expected to occur in the core of neutron stars. In this article, we
review the motivation for and the physics programme of CBM, including
activities before the start of data taking in 2022, in the context of the
worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal
СРЕДНИЕ ГОДОВЫЕ ЭФФЕКТИВНЫЕ ДОЗЫ ОБЛУЧЕНИЯ В 2014 ГОДУ ЖИТЕЛЕЙ НАСЕЛЕННЫХ ПУНКТОВ РОССИЙСКОЙ ФЕДЕРАЦИИ, ОТНЕСЕННЫХ К ЗОНАМ РАДИОАКТИВНОГО ЗАГРЯЗНЕНИЯ ВСЛЕДСТВИЕ КАТАСТРОФЫ НА ЧЕРНОБЫЛЬСКОЙ АЭС (ДЛЯ ЦЕЛЕЙ ЗОНИРОВАНИЯ НАСЕЛЕННЫХ ПУНКТОВ)
The Chernobyl accident in 1986 is one of the most large-scale radiation accidents in the world. It led to radioactive contamination of large areas in the European part of the Russian Federation and at the neighboring countries. Now, there are more than 4000 settlements with the total population of 1.5 million in the radioactively contaminated areas of the Russian Federation. The Bryansk region is the most intensely contaminated region. For example, the Krasnogorskiy district still has settlements with the level of soil contamination by cesium-137 exceeding 40 Cu/km2. The regions of Tula, Kaluga and Orel are also significantly affected. In addition to these four regions, there are 10 more regions with the radioactively contaminated settlements. After the Chernobyl accident, the affected areas were divided into zones of radioactive contamination. The attribution of the settlements to a particular zone is determined by the level of soil contamination with 137Cs and by a value of the average annual effective dose that could be formed in the absence of: 1) active measures for radiation protection, and 2) self-limitation in consumption of the local food products. The main regulatory document on this issue is the Federal law № 1244-1 (dated May, 15,1991) «On the social protection of the citizens who have been exposed to radiation as a result of the accident at the Chernobyl nuclear power plant». The law extends to the territories, where, since 1991: – The average annual effective dose for the population exceeds 1 mSv (the value of effective dose that could be formed in the absence of active radiation protection measures and self-limitation in consumption of the local food products); – Soil surface contamination with cesium-137 exceeds 1 Cu/km2. The paper presents results of calculations of the average effective doses in 2014. The purpose was to use the dose values (SGED90) in zonation of contaminated territories. Therefore, the calculations have been done under the assumption that the doses were formed in the absence of active radiation protection measures and self-limitation in consumption of the local food products. The dose to population, rather than the density of radioactive contamination of soil by 137Cs, is the most objective characteristic of the actual radiation exposure to the residents of the contaminated areas.Одна из самых масштабных радиационных катастроф в мире – авария на Чернобыльской АЭС (ЧАЭС) в 1986 г. – привела к радиоактивному загрязнению значительных территорий европейской части Российской Федерации и сопредельных государств. В настоящее время в зонах радиоактивного загрязнения Российской Федерации находится более 4 тыс. населенных пунктов, где проживают более1,5 млн человек. Наиболее интенсивно загрязнена Брянская область: так, в Красногорском районе до сих пор есть населенные пункты с радиоактивным загрязнением почвы цезием-137 выше 40 Ки/км2. Значительно пострадали также Тульская, Калужская и Орловская области. Кроме этих четырех областей, еще в 10 регионах страны имеются населенные пункты, расположенные в зонах радиоактивного загрязнения. После аварии на ЧАЭС пострадавшие территории были разбиты на зоны радиоактивного загрязнения. Отнесение НП к той или иной зоне определяется уровнем загрязнения почвы 137Cs и величиной средней годовой эффективной дозы облучения, которую могли бы получить жители в условиях отсутствия активных мер радиационной защиты и самоограничений в потреблении местных пищевых продуктов. Основным нормативным документом по данному вопросу является Федеральный закон от 15 мая 1991 г. № 1244-1 «О социальной защите граждан, подвергшихся воздействию радиации вследствие катастрофы на Чернобыльской АЭС», распространяющийся на территории, на которых, начиная с 1991 г.: – средняя годовая эффективная доза облучения населения превышает 1 мЗв/год – доза, которую могли бы получить жители в условиях отсутствия активных мер радиационной защиты и самоограничений в потреблении местных пищевых продуктов; – плотность радиоактивного загрязнения почвы цезием-137 превышает 1 Ки/км2. В статье приведены результаты расчетов средних годовых эффективных доз облучения населения в предполагаемых условиях отсутствия активных мер радиационной защиты, предназначенные для целей зонирования населенных пунктов (СГЭД90). Как известно, наиболее объективным качественным и количественным показателем оценки реального радиационного воздействия на жителей загрязненных территорий является доза облучения населения, а не плотность радиоактивного загрязнения почвы
Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications
Superparamagnetic iron oxide nanoparticles
can providemultiple benefits for biomedical applications
in aqueous environments such asmagnetic separation or
magnetic resonance imaging. To increase the colloidal
stability and allow subsequent reactions, the introduction
of hydrophilic functional groups onto the particles’
surface is essential. During this process, the original
coating is exchanged by preferably covalently bonded
ligands such as trialkoxysilanes. The duration of the
silane exchange reaction, which commonly takes more
than 24 h, is an important drawback for this approach. In
this paper, we present a novel method, which introduces
ultrasonication as an energy source to dramatically
accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove
the generic character, different functional groups were
introduced on the surface including polyethylene glycol
chains, carboxylic acid, amine, and thiol groups. Their
colloidal stability in various aqueous buffer solutions as
well as human plasma and serum was investigated to
allow implementation in biomedical and sensing
applications.status: publishe
A molecular-based identification resource for the arthropods of Finland
To associate specimens identified by molecular characters to other biological knowledge, we need reference sequences annotated by Linnaean taxonomy. In this study, we (1) report the creation of a comprehensive reference library of DNA barcodes for the arthropods of an entire country (Finland), (2) publish this library, and (3) deliver a new identification tool for insects and spiders, as based on this resource. The reference library contains mtDNA COI barcodes for 11,275 (43%) of 26,437 arthropod species known from Finland, including 10,811 (45%) of 23,956 insect species. To quantify the improvement in identification accuracy enabled by the current reference library, we ran 1000 Finnish insect and spider species through the Barcode of Life Data system (BOLD) identification engine. Of these, 91% were correctly assigned to a unique species when compared to the new reference library alone, 85% were correctly identified when compared to BOLD with the new material included, and 75% with the new material excluded. To capitalize on this resource, we used the new reference material to train a probabilistic taxonomic assignment tool, FinPROTAX, scoring high success. For the full-length barcode region, the accuracy of taxonomic assignments at the level of classes, orders, families, subfamilies, tribes, genera, and species reached 99.9%, 99.9%, 99.8%, 99.7%, 99.4%, 96.8%, and 88.5%, respectively. The FinBOL arthropod reference library and FinPROTAX are available through the Finnish Biodiversity Information Facility (www.laji.fi) at https://laji.fi/en/theme/protax. Overall, the FinBOL investment represents a massive capacity-transfer from the taxonomic community of Finland to all sectors of society.</p
4D Arctic: A Glimpse into the Structure and Evolution of the Arctic in the Light of New Geophysical Maps, Plate Tectonics and Tomographic Models
Structure des peuplements, régimes de perturbation et dynamiques de succession dans les forêts boréales eurasiennes : une revue basée sur des travaux russes
- …