Magnetic properties of Sn/1-x/Cr/x/Te diluted magnetic semiconductors

We present the studies of Sn/1-x/Cr/x/Te semimagnetic semiconductors with chemical composition x ranging from 0.004 to 0.012. The structural characterization indicates that even at low average Cr-content x < ?0.012, the aggregation into micrometer size clusters appears in our samples. The magnetic properties are affected by the presence of clusters. In all our samples we observe the transition into the ordered state at temperatures between 130 and 140 K. The analysis of both static and dynamic magnetic susceptibility data indicates that the spin-glass-like state is observed in our samples. The addition of Cr to the alloy seems to shift the spin-glass-like transition from 130 K for x = 0.004 to 140 K for x = 0.012.Comment: 4 pages, 4 figure

Adaptive strategy of Rapana venosa (Gastropoda, Muricidae) in the invasive population of the Black Sea

We conducted molecular-genetic and morphological studies on the veined rapa whelk Rapana venosa (Valenciennes, 1846) in the Crimean waters of the Black Sea in order to determine possible reasons of the invasive success of this mollusk. Molecular-genetic tests were performed using COI gene; the surveyed samples reliably identified to R. venosa species. We compared the data on initial (from the Far-Eastern seas) and some invasive populations. In the natural conditions of the Yellow, East China Seas, and the Sea of Japan, the genetic diversity of rapa whelk is high (Hd = 0.933, π = 0.002). In all the invasive populations of rapa whelk (Black Sea, European and North American), an extremely low level of haplotypic and nucleotide diversity was determined (Hd = 0.0, π = 0.0). Despite low values of genetic diversity, the invasive populations of rapa whelk are characterized by ecological success. We noted stable growth of populations, tolerance to diseases and parasites, effective reproduction, high fertility. This contradicts the main provisions of the population genetics theory of formation of edge of range populations, because usually only a small number of specimens of rapa whelk were introduced. The explanations of the unique condition of the invasive populations of rapa whelk, both from an ecological perspective (high resistance to fluctuations of hydrological factors and chemical pollution, absence of enemies, high fertility) and genetic perspective (high selective value of separate haplotypes settled in the new water areas) have not been confirmed. We&nbsp;determined that a very important factor for the naturalization of the rapa whelk at low genetic diversity is the intra-species morpho-ecological divergence. In the Crimean water area of the Black Sea, R. venosa was found to have two morpho-ecological forms associated with the peculiarities of the development of the proportions of the shell. Study of successful invasive species would allow timely and adequate reaction to new cases of introduction

Well-posedness and robust stability of a nonlinear ODE-PDE system

This work studies stability and robustness of a nonlinear system given as an interconnection of an ODE and a parabolic PDE subjected to external disturbances entering through the boundary conditions of the parabolic equation. To this end we develop an approach for a construction of a suitable coercive Lyapunov function as one of the main results. Based on this Lyapunov function we establish the well-posedness of the considered system and establish conditions that guarantee the ISS property. ISS estimates are derived explicitly for the particular case of globally Lipschitz nonlinearities.Comment: 41 page

Особенности учредительного процесса в деятельности Министерства внутренних дел Украины

Досліджено установчий процес як різновид юридичного процесу. До його особливостей у діяльності МВС України віднесено те, що він є результатом правового регулювання; не пов’язаний із наявністю спору про право; складається з певної послідовності проваджень (щодо органів і підрозділів − створення, реорганізація та ліквідація; щодо посадових осіб – призначення й усунення з посади); спрямований на формування, розвиток і вдосконалення інституційної та кадрової основи МВС; виступає як особливий нормативний порядок здійснення управлінської діяльності щодо реалізації відповідних правових норм; забезпечує ефективне функціонування механізму державного управління у відповідній сфері.The constituent process as a kind of legal process has been researched. Its specific features in the activity of the Ministry of Internal Affairs of Ukraine include the fact that it is the result of legal regulation, not related to the existence of a dispute about the right; consists of a certain sequence of proceedings (in regard to agencies and units – creation, reorganization and liquidation, in regard to officials – appointment and removal); aimed at the formation, development and improvement of the institutional and personnel basis of the Ministry of Internal Affairs; acts as a special regulatory procedure for carrying out management activity of the implementation of the relevant legal norms; ensures the effective functioning of the state administration mechanism in the relevant field. On the basis of theoretical analysis of legal literature, the author has determined that the regime of the constituent process in the activity of the Ministry of Internal Affairs first in its general theoretical aspect distinguishes, first of all the specificity of the formation of the corresponding agencies and units of the state or the appointment of officials depending on their subordinate position within the structure of the Ministry, in particular, and the mechanism of the state in general. It has been argued that the purpose of the constituent process is the formation, development and improvement of the relevant agencies and units, the appointment of officials, as well as their management. It has been determined that the reasons for the origin of this type of legal process in the activity of the Ministry of Internal Affairs are the relevant legal facts or legal status. One can study the main elements of the procedural form in the constituent process in the activities of the Ministry of Internal Affairs, which combine the specific features and characteristics of each type of legal process.Рассмотрен учредительный процесс как разновидность юридического процесса. К его особенностям в деятельности МВД Украины отнесено то, что он: является результатом правового регулирования; не связан с наличием спора о праве; состоит из определённой последовательности производств (относительно органов и подразделений – создание, реорганизация и ликвидация; в отношении должностных лиц – назначение и отстранение от должности); направлен на формирование, развитие и совершенствование институциональной и кадровой основы МВД; выступает как особый нормативный порядок осуществления управленческой деятельности по реализации соответствующих правовых норм; обеспечивает эффективное функционирование механизма государственного управления в соответствующей сфере

The magnetic interactions in spin-glasslike Ge/1-x-y/Sn/x/Mn/y/Te diluted magnetic semiconductor

We investigated the nature of the magnetic phase transition in the Ge/1-x-y/Sn/x/Mn/y/Te mixed crystals with chemical composition changing in the range of 0.083 < x < 0.142 and 0.012 < y < 0.119. The DC magnetization measurements performed in the magnetic field up to 90 kOe and temperature range 2-200 K showed that the magnetic ordering at temperatures below T = 50 K exhibits features characteristic for both spin-glass and ferromagnetic phases. The modified Sherrington - Southern model was applied to explain the observed transition temperatures. The calculations showed that the spin-glass state is preferred in the range of the experimental carrier concentrations and Mn content. The value of the Mn hole exchange integral was estimated to be J/pd/ = 0.45+/-0.05 eV. The experimental magnetization vs temperature curves were reproduced satisfactory using the non-interacting spin-wave theory with the exchange constant J/pd/ values consistent with those calculated using modified Sherrington - Southern model. The magnetization vs magnetic field curves showed nonsaturating behavior at magnetic fields B < 90 kOe indicating the presence of strong magnetic frustration in the system. The experimental results were reproduced theoretically with good accuracy using the molecular field approximation-based model of a disordered ferromagnet with long-range RKKY interaction.Comment: 9 pages, 6 figure

Розмірно-вагова структура карабідофауни навколоводних амфіценозів Присамар’я Дніпровського

Исследована размерно-весовой структуру группировок жужелиц околоводных амфиценозив Присамарья Днепровского по количеству видов и биомассой. Проанализировано соотношение размерно-весовых групп в гигрофильних биотопах поймы, арены, солонцовыми-солончаковой и надпойменной террас. Определены индексы разнообразия Шеннона и пил комплексов жужелиц по размерно-весовой структуре.Size-weight structure of ground beetles complexes in subaquatic ecosystems of Prysamar’ya Dniprovs’ke (Dnipropetrovs’k region) was studied by distribution of species quantity and biomass. The principles of size-weight groups’ distribution in subaquatic ecosystems of floodland, sandy, saline and suprafloodland terraces were analyzed. Shannon and Pielou species diversity indices of Carabidae were determined. Досліджено розмірно-вагову структуру угруповань турунів навколоводних амфіценозів Присамар’я Дніпровського за кількістю видів та біомасою. Проаналізовано співвідношення розмірно-вагових груп у гігрофільних біотопах заплави, арени, солонцево-солончакової та надзаплавної терас. Визначено індекси різноманіття Шеннона та Пілоу комплексів турунів за розмірно-ваговою структурою.

Morphology of PbTe crystal surface sputtered by argon plasma under Secondary Neutral Mass Spectrometry conditions

We have investigated morphology of the lateral surfaces of PbTe crystal samples grown from melt by the Bridgman method sputtered by Ar+ plasma with ion energy of 50-550 eV for 5-50 minutes under Secondary Neutral Mass Spectrometry (SNMS) conditions. The sputtered PbTe crystal surface was found to be simultaneously both the source of sputtered material and the efficient substrate for re-deposition of the sputtered material during the depth profiling. During sputtering PbTe crystal surface is forming the dimple relief. To be redeposited the sputtered Pb and Te form arrays of the microscopic surface structures in the shapes of hillocks, pyramids, cones and others on the PbTe crystal sputtered surface. Correlation between the density of re-deposited microscopic surface structures, their shape, and average size, on the one hand, and the energy and duration of sputtering, on the other, is revealed

Roughness of dichotomy for the interconnected system of operator-differential equations

The paper is devoted to obtaining conditions for the roughness of dichotomy in the Banach spaces. Deep analysis of the well known papers was considered. The main results also works for the case of unbounded operators