895 research outputs found
THE LEVELS OF FORMATION OF UKRAINIAN UNIVERSITY STUDENTS' PERSONAL SELF-DETERMINATION IN HIGHER EDUCATION
Purpose: The article defines the levels of formation of the culture of personal self-determination of students of Ukrainian higher education institutions, namely, the formation of culture. This study uses the functional model to emphasize that self-determined behaviors must be defined within the context of the purpose or utility of such behavior for the student.
Methodology: Analyze the process of developing students' self-confidence in its social perspective on the basics of Ukrainian education using questionnaires, tests and surveys. The examination included 348 understudies from the control (178 people) and trial (170 people) gatherings and the confirmation phase of the analysis was held at three colleges.
Result: Diagnosis and analysis showed the reasons for the low and middle levels of the formation of the culture of personal self-determination of students because there is no clear definition in the content, forms and methods of work. In general, the distribution of students by the levels of effectiveness of life assignments will be illustrated.
Applications: This research can be used for the universities, teachers, and students. This qualitative study used a participatory action approach (focus group) to evaluate the perception of teachers, youth and parents of diverse ethnicities with regard to cultural influences on self-determination. Eight groups consisted of youth only, eight of parents only and four groups of teachers only.
Novelty/Originality: In this research, the model of the Ukrainian University Students' Self-Determination: Culture Formation Aspect is presented in a comprehensive and complete manner. Also, the main originality used in this study is in the case studies investigated. The cases were students who are the autonomous adolescences among all classified different age groups
Evolution of the Velocity Ellipsoids in the Thin Disk of the Galaxy and the Radial Migration of Stars
Data from the revised Geneva--Copenhagen catalog are used to study the
influence of radial migration of stars on the age dependences of parameters of
the velocity ellipsoids for nearby stars in the thin disk of the Galaxy,
assuming that the mean radii of the stellar orbits remain constant. It is
demonstrated that precisely the radial migration of stars, together with the
negative metallicity gradient in the thin disk,are responsible for the observed
negative correlation between the metallicities and angular momenta of nearby
stars, while the angular momenta of stars that were born at the same
Galactocentric distances do not depend on either age or metallicity. (abridged)Comment: Astronomy Reports, Vol. 86 No. 9, P.1117-1126 (2009
Quantum dissociation of a vortex-antivortex pair in a long Josephson junction
We report a theoretical analysis and experimental observation of the quantum
dynamics of a single vortex-antivortex (VAV) pair confined in a long narrow
annular Josephson junction. The switching of the junction from the
superconducting state to the resistive state occurs via the dissociation of a
pinned VAV pair. The pinning potential is controlled by external magnetic field
and dc bias current . We predict a specific magnetic field dependence of
the oscillatory energy levels of the pinned VAV state and the crossover to a
{\it macroscopic quantum tunneling} mechanism of VAV dissociation at low
temperatures. Our analysis explains the experimentally observed {\it increase}
of the width of the switching current distribution with and the
crossover to the quantum regime at the temperature of about 100 mK.Comment: 4 pages, 3 figure
Superconducting joining of melt-textured Y-Ba-Cu-O bulk material
The Tm-Ba-Cu-O solder can be successfully used to produce a superconductive
joint between MT-YBCO parts. The peculiarities of solidification, phase
formation, structure transformations and electromagnetic properties of MT-YBCO
soldered with TmBa2Cu3O7-d are discussed.Comment: PS of 6 pages text and 5 figures, presented at ICMC'2000, Brasi
Numerical simulation of discharge plasma generation and nitriding the metals and alloys
This research provides the numerical simulation of the plasma generation in a hollow cathode as well as the diffusion of nitrogen atoms into the metal in the low-pressure glow discharge plasma. The characteristics of the gas discharge were obtained and the relation of the basic technological parameters and the structural and phase state of the nitrided material were defined. Authors provided the comparison of calculations with the experimental results of titanium nitriding by low-pressure glow discharge plasma in a hollow cathode
Can recombinant tree shrew (Tupaia belangeri chinensis) chymosin coagulate cow (Bos taurus) milk?
Genetically engineered chymosin from the tree shrew (Tupaia belangeri chinensis) has been obtained and partially characterized for the first time. The target enzyme was produced in Escherichia coli, strain BL21(DE3). It was shown that tree shrew recombinant chymosin coagulates cow milk (Bos taurus). The total and specific milk-clotting activity of the obtained enzyme was 0.7–5.3 IMCU/mL and 8.8–16.6 IMCU/mg. The nonspecific proteolytic activity of tree shrew recombinant chymosin in relation to total bovine casein was 30 and 117% higher than that of recombinant chymosin of cow and of single-humped camel respectively. It was found that in comparison with most of the known genetically engineered chymosins, the tree shrew enzyme showed exceptionally low thermal stability. After heating at 45°C, the coagulation ability of tree shrew recombinant chymosin decreased by more than 40%, and at 50°C the enzyme lost more than 90% of the initial milk-clotting activity. The Michaelis constant (Km), enzyme turnover number (kcat), and catalytic efficiency (kcat/Km) for genetically engineered chymosin from the tree shrew were 6.3 ± 0.1 µM, 11 927 ± 3169 s–1 and 1968 ± 620 µM–1 s–1, respectively. Comparative analysis showed that the primary structure of the chymosin-sensitive site of cow kappa-casein and the supposed similar sequence of tree shrew kappa-casein differed by 75%. The ability of tree shrew recombinant chymosin to coagulate cow’s milk, along with a low thermal stability and high catalytic efficiency with respect to the substrate, imitating the chymosin-sensitive site of cow kappa-casein, suggests that this enzyme is of potential interest for cheese making
Relationship between the Velocity Ellipsoids of Galactic-Disk Stars and their Ages and Metallicities
The dependences of the velocity ellipsoids of F-G stars of the thin disk of
the Galaxy on their ages and metallicities are analyzed based on the new
version of the Geneva-Copenhagen Catalog. The age dependences of the major,
middle, and minor axes of the ellipsoids, and also of the dispersion of the
total residual veltocity, obey power laws with indices 0.25,0.29,0.32, and 0.27
(with uncertainties \pm 0.02). Due to the presence of thick-disk objects, the
analogous indices for all nearby stars are about a factor of 1.5 larger.
Attempts to explain such values are usually based on modeling relaxation
processes in the Galactic disk. With increasing age, the velocity ellipsoid
increases in size and becomes appreciably more spherical, turns toward the
direction of the Galactic center, and loses angular momentum. The shape of the
velocity ellipsoid remains far from equilibrium. With increasing metallicity,
the velocity ellipsoid for stars of mixed age increases in size, displays a
weak tendency to become more spherical, and turns toward the direction of the
Galactic center (with these changes occurring substantially more rapidly in the
transition through the metallicity [Fe/H]= -0.25). Thus, the ellipsoid changes
similarly to the way it does with age; however, with decreasing metallicity,
the rotational velocity about the Galactic center monotonically increases,
rather than decreases(!). Moreover, the power-law indices for the age
dependences of the axes depend on the metallicity, and display a maximum near
[Fe/H]=-0.1. The age dependences of all the velocity-ellipsoid parameters for
stars with equal metallicity are roughly the same. It is proposed that the
appearance of a metallicity dependence of the velocity ellipsoids for thin-disk
stars is most likely due to the radial migration of stars.Comment: 15 pages, 6 figures, accepted 2009, Astronomy Reports, Vol. 53 No. 9,
P.785-80
Kinetics of substrate recognition and cleavage by human 8-oxoguanine-DNA glycosylase
Human 8-oxoguanine-DNA glycosylase (hOgg1) excises 8-oxo-7,8-dihydroguanine (8-oxoG) from damaged DNA. We report a pre-steady-state kinetic analysis of hOgg1 mechanism using stopped-flow and enzyme fluorescence monitoring. The kinetic scheme for hOgg1 processing an 8-oxoG:C-containing substrate was found to include at least three fast equilibrium steps followed by two slow, irreversible steps and another equilibrium step. The second irreversible step was rate-limiting overall. By comparing data from Ogg1 intrinsic fluorescence traces and from accumulation of products of different types, the irreversible steps were attributed to two main chemical steps of the Ogg1-catalyzed reaction: cleavage of the N-glycosidic bond of the damaged nucleotide and β-elimination of its 3′-phosphate. The fast equilibrium steps were attributed to enzyme conformational changes during the recognition of 8-oxoG, and the final equilibrium, to binding of the reaction product by the enzyme. hOgg1 interacted with a substrate containing an aldehydic AP site very slowly, but the addition of 8-bromoguanine (8-BrG) greatly accelerated the reaction, which was best described by two initial equilibrium steps followed by one irreversible chemical step and a final product release equilibrium step. The irreversible step may correspond to β-elimination since it is the very step facilitated by 8-BrG
Кафедре оптических и оптико-электронных приборов – 40 лет
Розглянуто історію заснування кафедри оптичних приладів в Київському політехнічному інституті. Представлена інформація про усіх завідувачів кафедри, підготовку інженерних і наукових кадрів, науково-методичні школи кафедри. Зроблено висновок про перспективи оптичного приладобудування в Україні.The history of the department of optical and optic-electronic devices in Kiev polytechnic institute is considered. The information about all the chiefs of the department, engineering education, scientific and methodological schools is given. The future of the optical instrument engineering
in Ukraine is concluded.Рассмотрена история основания кафедры оптических приборов в Киевском политехническом институте. Представлена информация о всех заведующих кафедрой, подготовке инженерных и научных кадров, научно-методических школах кафедры. Сделан вывод о перспективах оптического приборостроения в Украине
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