351 research outputs found
On evolution of libration points similar to eulerian in the model problem of the binary-asteroids dynamics
The binary asteroids are of current interest in the modern dynamics as there have been up to 50 discoveries of binaries. Estimates are that about 20% of near-Earth asteroids may be binary asteroids. Nevertheless the known asteroids pairs are rather rare objects in the Solar System. There are a number of papers studying the various aspects of asteroid pair dynamics. In this paper we study some stationary motions in the system of binary asteroid. Using the model for the first time suggested in [1], we approximate the bigger asteroid by the dumbbell-shaped rigid body. Moreover we assume that the smaller asteroid has mass close to zero. It was shown in [1] that the motion equations for the considered system have the stationary solutions corresponding to the smaller asteroid's equilibria relative to the axis of the regular precession and the dumbbell rod These equilibria similar to the libration points in the Restricted Circular Problem of Three Bodies (RCP3B). There are two types of such equilibria. The equal distances from the dumbbell endpoints characterize the equilibria of the first type, therefore we shall name them ‘the libration points similar to Lagrangian’ or ‘the triangular libration points’ (TLPs) by analogy to a classical problem. At difference with RCP3B there are two or one TLPs or they do not exist. Equilibria of the second type in something are similar to the Eulerian libration points. They belong to the plane containing the bigger asteroid's angular momentum and the dumbbell rod. Moreover, these equilibria belong to the strip bounded by straight lines crossing the dumbbell endpoints and being perpendicular to angular momentum. Therefore we shall name them ‘the coplanar libration points’(CLP). The CLPs coordinates are computed by following procedure. Two algebraic equations are deduced. One of these equations determines the curve containing all CLPs. We say that this curve is ‘the Geometrical locus of CLPs’ (GL). The second equation allows to locate CLPs in GL. Studying evolution of CLPs in GL it can be proved that the number of CLPs varies from 3 up to 7, but if the dumbbell consist of equal spheres then only the odd number of CLPs is possible. However, if the dumbbell is asymmetric then the number of CLPs can be equal 4 or 6 for some rare situation
A Unification of Models of Tethered Satellites
In this paper, different conservative models of tethered satellites are related mathematically, and it is established in what limit they may provide useful insight into the underlying dynamics. An infinite dimensional model is linked to a finite dimensional model, the slack-spring model, through a conjecture on the singular perturbation of tether thickness. The slack-spring model is then naturally related to a billiard model in the limit of an inextensible spring. Next, the motion of a dumbbell model, which is lowest in the hierarchy of models, is identified within the motion of the billiard model through a theorem on the existence of invariant curves by exploiting Moser's twist map theorem. Finally, numerical computations provide insight into the dynamics of the billiard model
On evolution of libration points similar to eulerian in the model problem of the binary-asteroids dynamics
The binary asteroids are of current interest in the modern dynamics as there have been up to 50 discoveries of binaries. Estimates are that about 20% of near-Earth asteroids may be binary asteroids. Nevertheless the known asteroids pairs are rather rare objects in the Solar System. There are a number of papers studying the various aspects of asteroid pair dynamics. In this paper we study some stationary motions in the system of binary asteroid. Using the model for the first time suggested in [1], we approximate the bigger asteroid by the dumbbell-shaped rigid body. Moreover we assume that the smaller asteroid has mass close to zero. It was shown in [1] that the motion equations for the considered system have the stationary solutions corresponding to the smaller asteroid's equilibria relative to the axis of the regular precession and the dumbbell rod These equilibria similar to the libration points in the Restricted Circular Problem of Three Bodies (RCP3B). There are two types of such equilibria. The equal distances from the dumbbell endpoints characterize the equilibria of the first type, therefore we shall name them ‘the libration points similar to Lagrangian’ or ‘the triangular libration points’ (TLPs) by analogy to a classical problem. At difference with RCP3B there are two or one TLPs or they do not exist. Equilibria of the second type in something are similar to the Eulerian libration points. They belong to the plane containing the bigger asteroid's angular momentum and the dumbbell rod. Moreover, these equilibria belong to the strip bounded by straight lines crossing the dumbbell endpoints and being perpendicular to angular momentum. Therefore we shall name them ‘the coplanar libration points’(CLP). The CLPs coordinates are computed by following procedure. Two algebraic equations are deduced. One of these equations determines the curve containing all CLPs. We say that this curve is ‘the Geometrical locus of CLPs’ (GL). The second equation allows to locate CLPs in GL. Studying evolution of CLPs in GL it can be proved that the number of CLPs varies from 3 up to 7, but if the dumbbell consist of equal spheres then only the odd number of CLPs is possible. However, if the dumbbell is asymmetric then the number of CLPs can be equal 4 or 6 for some rare situation
The complete mitochondrial genome of the acid-tolerant fungus Penicillium ShG4C
AbstractComplete mitochondrial genome of the acid-tolerant fungus Penicillium ShG4C, isolated from oxidized sediments of an abandoned polymetallic mine site, has been sequenced using high-throughput sequencing approach. The mitochondrial genome represents a circular DNA molecule with size of 26,725bp. It encodes a usual set of mitochondrial genes, including 15 protein coding genes, large and small ribosomal RNAs and 27 tRNA genes. All genes are located on H-strand DNA and transcribed in one direction. Taxonomic analysis based on concatenated sequences of mitochondrial proteins confirmed taxonomic position of this fungus within the genus Penicillium. The sequence of the complete mitochondrial genome of Penicillium ShG4C was deposited in DBBJ/EMBL/GenBank under accession number KX931017
Lignite coal burning seam in the remote Altai Mountains harbors a hydrogen-driven thermophilic microbial community
Thermal ecosystems associated with underground coal combustion sites are rare and less studied than geothermal features. Here we analysed microbial communities of near-surface ground layer and bituminous substance in an open quarry heated by subsurface coal fire by metagenomic DNA sequencing. Taxonomic classification revealed dominance of only a few groups of Firmicutes. Near-complete genomes of three most abundant species, ‘Candidatus Carbobacillus altaicus’ AL32, Brockia lithotrophica AL31, and Hydrogenibacillus schlegelii AL33, were assembled. According to the genomic data, Ca. Carbobacillus altaicus AL32 is an aerobic heterotroph, while B. lithotrophica AL31 is a chemolithotrophic anaerobe assimilating CO2 via the Calvin cycle. H. schlegelii AL33 is an aerobe capable of both growth on organic compounds and carrying out CO2 fixation via the Calvin cycle. Phylogenetic analysis of the large subunit of RuBisCO of B. lithotrophica AL31 and H. schlegelii AL33 showed that it belongs to the type 1-E. All three Firmicutes species can gain energy from aerobic or anaerobic oxidation of molecular hydrogen, produced as a result of underground coal combustion along with other coal gases. We propose that thermophilic Firmicutes, whose spores can spread from their original geothermal habitats over long distances, are the first colonizers of this recently formed thermal ecosystem
Genome sequence of the acid-tolerant Desulfovibrio sp. DV isolated from the sediments of a Pb-Zn mine tailings dam in the Chita region, Russia
Here we report the draft genome sequence of the acid-tolerant Desulfovibrio sp. DV isolated from the sediments of a Pb-Zn mine tailings dam in the Chita region, Russia. The draft genome has a size of 4.9 Mb and encodes multiple K+-transporters and proton-consuming decarboxylases. The phylogenetic analysis based on concatenated ribosomal proteins revealed that strain DV clusters together with the acid-tolerant Desulfovibrio sp. TomC and Desulfovibrio magneticus. The draft genome sequence and annotation have been deposited at GenBank under the accession number MLBG00000000
Genome sequence of the copper resistant and acid-tolerant Desulfosporosinus sp. BG isolated from the tailings of a molybdenum-tungsten mine in the Transbaikal area
Here, we report on the draft genome of a copper-resistant and acidophilic Desulfosporosinus sp. BG, isolated from the tailings of a molybdenum-tungsten mine in Transbaikal area. The draft genome has a size of 4.52 Mb and encodes transporters of heavy metals. The phylogenetic analysis based on concatenated ribosomal proteins revealed that strain BG clusters together with the other acidophilic copper-resistant strains Desulfosporosinus sp. OT and Desulfosporosinus sp. I2. The K+-ATPase, Na+/H+ antiporter and amino acid decarboxylases may participate in enabling growth at low pH. The draft genome sequence and annotation have been deposited at GenBank under the accession number NZ_MASS00000000
ОСОБЛИВОСТІ ФОРМУВАННЯ ПРОГРАМНИХ РЕЗУЛЬТАТІВ НАВЧАННЯ ЗДОБУВАЧІВ ВИЩОЇ ОСВІТИ ПЕРШОГО (БАКАЛАВРСЬКОГО) РІВНЯ ВИЩОЇ ОСВІТИ ЗА СПЕЦІАЛЬНІСТЮ «ГІДРОТЕХНІЧНЕ БУДІВНИЦТВО, ВОДНА ІНЖЕНЕРІЯ ТА ВОДНІ ТЕХНОЛОГІЇ»
Relevance of research. The reform of higher education in Ukraine is to create a system to ensure and constantly improve its quality, which meets the recommendations and standards of the European Higher Education Area (EHEA), takes into account international best practices and provides for the development of a new generation standards based on a competent approach.
Objective of research. It is necessary to create a substantiated system of competencies and training program results, combining a scientific and methodological approach that takes into account the needs of stakeholders: higher education applicants, employers, society and the state.
Methods and techniques of research. Approbation of the training of applicants for the first (bachelor) level of higher education according to the formed list of training program results on a specialty is conducted in National University of Water and Environmental Engineering, according to the corresponding educational and professional program, which has been certified for the first time in 2020.
Results of research and conclusions. On the example of the formation of training program results of the applicants for the first (bachelor) level of higher education on the specialty 194 "Hydraulic Engineering, Water Engineering and Water Technology", we tried to show how to take into account the suitability of graduates for the employment by the professional titles of jobs corresponding to the level of "Specialists" in National Classification of Jobs (DK 003: 2010). The correspondence of professional titles of jobs and professions according to DK 003: 2010 to the International Standard Classification of Jobs (ISCO-08) is given. The article evaluates the suitability of a university graduate to perform professional tasks and responsibilities defined in the qualification characteristics and job descriptions of specialists in the field of water management, in comparison with the program results of higher education received by the graduate. In continuation of the discussion on the search for perspective approaches to the formation of a modern technical specialist, we consider that one of the important mechanisms is the production practice and personalized implementation of course design and bachelor's project. All that will form the necessary program results of the graduate's education, develop the personality of the young specialist and allow him to socialize successfully, conduct professional and / or further educational activities.
Prospects. The comparison given in the article shows the importance of the formation of training program results in the standards of higher education, taking into account the requirements of the specific profession for which the higher education applicant is preparing. These requirements are defined in the qualifications and job descriptions. A high school graduate, having got the first job, must demonstrate training program results that will allow him to perform tasks and responsibilities in accordance with job descriptions.Реформування вищої освіти в Україні полягає у створенні системи забезпечення та постійного поліпшення її якості, що відповідає рекомендаціям і стандартам Європейського простору вищої освіти (ЄПВО), враховує кращі світові практики та передбачає на основі компетентністного підходу розроблення стандартів нового покоління. Тому необхідно створити обґрунтовану систему компетентностей та програмних результатів навчання, поєднуючи науково-методологічний підхід із врахуванням потреб стейкхолдерів: здобувачів вищої освіти, роботодавців, суспільства і держави. На прикладі формування програмних результатів навчання здобувачів першого (бакалаврського) рівня вищої освіти за спеціальністю 194 «Гідротехнічне будівництво, водна інженерія та водні технології» ми намагались показати, як враховується придатність випускників до працевлаштування за професійними назвами робіт, що відповідають рівню «Фахівці» за «Національним класифікатором професій» (ДК 003:2010). Наводиться відповідність професійних назв робіт і професій за ДК 003:2010 до Міжнародної стандартної класифікації професій (ISCO-08). В статті приводиться оцінювання придатності випускника ЗВО до виконання професійних завдань і обов’язків, що визначені у кваліфікаційних характеристиках та посадових інструкціях фахівців водогосподарської сфери діяльності порівняно з отриманими здобувачем вищої освіти програмними результатами навчання. Як продовження дискусії про пошук перспективних підходів до формування сучасного технічного фахівця ми вважаємо, що одним із важливих механізмів є виробнича практика та персоніфіковане виконання курсового проектування та кваліфікаційної бакалаврської. Все це сформує необхідні програмні результати навчання випускника, розвине особистість молодого фахівця та дозволить йому успішно соціалізуватися, провадити професійну та/або подальшу навчальну діяльність
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