Theoretical and numerical studies of wave-packet propagation in tokamak plasmas

Theoretical and numerical studies of wave-packet propagation are presented to analyze the time varying 2D mode structures of electrostatic fluctuations in tokamak plasmas, using general flux coordinates. Instead of solving the 2D wave equations directly, the solution of the initial value problem is used to obtain the 2D mode structure, following the propagation of wave-packets generated by a source and reconstructing the time varying field. As application, the 2D WKB method is applied to investigate the shaping effects (elongation and triangularity) of tokamak geometry on the lower hybrid wave propagation and absorbtion. Meanwhile, the Mode Structure Decomposition (MSD) method is used to handle the boundary conditions and simplify the 2D problem to two nested 1D problems. The MSD method is related to that discussed earlier by Zonca and Chen [Phys. Fluids B 5, 3668 (1993)], and reduces to the well-known "ballooning formalism" [J. W. Connor, R. J. Hastie, and J. B. Taylor, Phys. Rev. Lett. 40, 396 (1978)], when spatial scale separation applies. This method is used to investigate the time varying 2D electrostatic ITG mode structure with a mixed WKB-full-wave technique. The time varying field pattern is reconstructed and the time asymptotic structure of the wave-packet propagation gives the 2D eigenmode and the corresponding eigenvalue. As a general approach to investigate 2D mode structures in tokamak plasmas, our method also applies for electromagnetic waves with general source/sink terms, either by an internal/external antenna or nonlinear wave interaction with zonal structures.Comment: 24 pages, 14 figure

ПРИМЕНЕНИЕ КОРРЕЛЯЦИОННОГО АНАЛИЗА ДВУМЕРНОГО CТОХАCТИЧЕCКОГО ПРОЦЕCCА ДЛЯ ОЦЕНКИ ЭКCПЛУАТАЦИОННОЙ ТЕХНОЛОГИЧНОCТИ ВЕРТОЛЕТА

The new calculated program complex which main task is to find the optimal algorithm of stochastic helicopter de- sign and assembling in terms of maintenance efficiency is described. It is shown that the use of the developed calculated program complex allows to efficiently solve the problems of helicopter construction with high-rating maintenance worka- bility factors.It is shown that for efficient problem solving connected with Maintenance and Repair costs reduction while heli- copter engineering and assembling in design office it is appropriate to use correlated analysis for maintenance workability estimation with the use of CAD system. The calculated program complex is based on mathematical apparatus of linear cor-related dependence of two-dimension (stochastic) process. The linear correlated dependence is considered as linear or anyconnection close to it between two variables for which the correlated analysis theorem is true.The algorithm of calculated program complex for helicopter maintenance workability estimation consists of five steps: choice of equipment that needs to be installed on the helicopter; correlation coefficient calculation for helicopters having this equipment and revealing of optimal variants of location; zone partition of the developed helicopter and analysis of possi- ble disposal of clusters in optimal order; disposal of clusters on the designed helicopter; correlation coefficient calculation, direct regression construction for the designed helicopter and comparison of these readings with helicopters-analogues. The calculation data of correlated analysis characteristics which indicate a possibility of increase of helicopter maintenance worka- bility level with a modicum of effort and time when working out the particular functional system is given.Описывается новый расчетный программный комплекс, в задачи которого входит поиск оптимального с точки зрения эффективности технической эксплуатации вертолетной техники алгоритма стохастического конструирования и компоновки вертолета. Показано, что использование разработанного расчетного программного комплекса позволяет успешно решать задачи обеспечения конструкции вертолета с высокими показателями эксплуатационной технологичности.Показано, что для успешного решения задач, связанных со снижением (на этапах эксплуатации) затрат на техническое обслуживание и ремонт при проектировании и компоновке вертолета в конструкторском бюро, целесообразно применение корреляционного анализа для оценки эксплуатационной технологичности совместно с ис-пользованием системы автоматизированного проектирования. За основу расчетного программного комплекса взятматематический аппарат линейной корреляционной зависимости двумерного (стохастического) процесса. Под ли-нейной корреляционной зависимостью понимается линейная или близкая к ней связь между двумя переменными,для которой справедлива теорема корреляционного анализа.Представлен алгоритм работы расчетного программного комплекса для оценки эксплуатационной техно-логичности вертолета, который состоит из пяти шагов: выбор оборудования, которое необходимо установить навертолет (блоки); подсчет коэффициента корреляции для вертолетов, имеющих данное оборудование и выявлениеоптимальных вариантов расположения; зональное деление разрабатываемого вертолета и анализ возможности раз-мещения блоков в оптимальном порядке; размещение блоков на проектируемом вертолете; подсчет коэффициентакорреляции, построение прямой регрессии для проектируемого вертолета и сравнение данных показателей с вер-толетами-аналогами. Приведены результаты расчета характеристик корреляционного анализа, которые свидетель-ствуют о потенциальной возможности повышения уровня эксплуатационной технологичности вертолета с мини-мальными затратами труда и времени при разработке отдельной функциональной системы

Hadronic Regge Trajectories: Problems and Approaches

We scrutinized hadronic Regge trajectories in a framework of two different models --- string and potential. Our results are compared with broad spectrum of existing theoretical quark models and all experimental data from PDG98. It was recognized that Regge trajectories for mesons and baryons are not straight and parallel lines in general in the current resonance region both experimentally and theoretically, but very often have appreciable curvature, which is flavor-dependent. For a set of baryon Regge trajectories this fact is well described in the considered potential model. The standard string models predict linear trajectories at high angular momenta J with some form of nonlinearity at low J.Comment: 15 pages, 9 figures, LaTe

Improved SOT (Hinode mission) high resolution solar imaging observations

We consider the best today available observations of the Sun free of turbulent Earth atmospheric effects, taken with the Solar Optical Telescope (SOT) onboard the Hinode spacecraft. Both the instrumental smearing and the observed stray light are analyzed in order to improve the resolution. The Point Spread Function (PSF) corresponding to the blue continuum Broadband Filter Imager (BFI) near 450 nm is deduced by analyzing i/ the limb of the Sun and ii/ images taken during the transit of the planet Venus in 2012. A combination of Gaussian and Lorentzian functions is selected to construct a PSF in order to remove both smearing due to the instrumental diffraction effects (PSF core) and the large-angle stray light due to the spiders and central obscuration (wings of the PSF) that are responsible for the parasitic stray light. A Max-likelihood deconvolution procedure based on an optimum number of iterations is discussed. It is applied to several solar field images, including the granulation near the limb. The normal non-magnetic granulation is compared to the abnormal granulation which we call magnetic. A new feature appearing for the first time at the extreme- limb of the disk (the last 100 km) is discussed in the context of the definition of the solar edge and of the solar diameter. A single sunspot is considered in order to illustrate how effectively the restoration works on the sunspot core. A set of 125 consecutive deconvolved images is assembled in a 45 min long movie illustrating the complexity of the dynamical behavior inside and around the sunspot.Comment: 15 pages, 22 figures, 1 movi

STUDY OF MINIMAL RESIDUAL DISEASE BY MULTICOLOR FLOW CYTOMETRY IN MULTIPLE MYELOMA AFTER AUTOLOGOUS HEMATOPOIETIC STEM CELL TRANSPLANTATION

The frequency of achieving complete remission, as well as overall and disease-free survival, in multiple myeloma (MM) had increased due to introduction in MM treatment regimens of high-dose chemotherapy with following autologous hematopoietic stem cell transplantation (ASCT). However the number of relapses remains high, caused by persistence of residual tumor cells, i.e., the presence of minimal residual disease (MRD). One of the methods for MRD study is multicolor flow cytometry (MFC) where abnormal expression of surface antigens on myeloma plasma cells (PC) is determined. The aim of our study was to investigate the MRD by MFC before and after ASCT, the frequency of MRD-negative status achievement in complete remission (CR) patients at +100 days after ASCT and the frequency of abnormal expressed antigens on myeloma plasma cells. The study included40 MMpatients in CR at +100 days after ASCT and showed that the most common aberrations of PC were: abnormal absence of CD19 and/or CD27, decreased expression of CD38 and abnormal presence of CD56. The proportion of myeloma PCs from all bone marrow cells decreased significantly after ASCT: 20 % of patients acquired MRD-negative status, 10 % had a decrease in the number of abnormal PCs by one fold. Analysis of probability of immunochemical relapse showed that the worst prognosis was in patients with MRD-positive status before and after ASCT. During the MRD monitoring within 3-18 months, MRD-relapses were detected with the subsequent development of immunochemical relapse. The detection MRD in the dynamics is more informative than the study at only one step of therapy. It may help to select more adequate treatment for patient with multiple myeloma in each specific case

ДИАГНОСТИКА ТЕХНОЛОГИЧЕСКИХ ХАРАКТЕРИСТИК МОЩНЫХ ТРАНЗИСТОРОВ С ПОМОЩЬЮ РЕЛАКСАЦИОННОГО ИМПЕДАНС–СПЕКТРОМЕТРА ТЕПЛОВЫХ ПРОЦЕССОВ

The efficient method of determining thermal parameters in high-power field-effect transistors has been developed and tested based on a study of transient processes during self heating by direct current. With the developed relaxation spectrometer of thermal processes differential distribution profiles of thermal resistance of KP723G transistors have been investigated which were selected in accordance with the regimes of setting of their crystals. Thermal resistance spectra have been obtained from the analysis of time−dependent dynamic thermal impedance using a new non−destructive method of differential spectroscopy using higher order derivatives (order 3). We present both continuous (integral) and discrete spectra of the distribution of internal thermal resistance in the transistors and the value of the junction/case thermal resistance. Thermal characteristics of the KP723G transistors and their imported counterparts IRLZ44 and IRLB3036 have been determined. The method of determining the active area of devices has been developed and its decrease during heating has been shown. The proposed methodology is useful in solving technological problems of forming the setting layers of crystals and intermediate layers between a crystal and a heat sink and also for the development of thermal models in SPICE modeling of powerful MOSFETs and diode emitters.На основе исследования переходных процессов при саморазогреве прямым током разработан и апробирован эффективный метод определения тепловых параметров мощных полевых транзисторов. С помощью разработанного релаксационного спектрометра тепловых процессов исследованы дифференциальные профили распределения теплового сопротивления транзисторов КП723Г, подобранных в партии в соответствии с режимами посадки их кристаллов на теплоотводящее основание. Спектры тепловых сопротивлений рассчитаны из анализа временной зависимости динамического теплового импеданса новым неразрушающим методом дифференциальной спектроскопии с использованием производных высших порядков (3-го порядка). Представлены как непрерывные (интегральные), так и дискретные спектры распределения внутреннего теплового сопротивления транзисторов, а также значения теплового сопротивления переход—корпус. Определены тепловые характеристики транзисторов КП723Г и их импортных аналогов IRLZ44 и IRLB3036. Развит метод оценки активной площади приборов и установлено ее уменьшение с нагревом. Показано, что предложенные методики полезны при решении технологических проблем формирования слоев посадки кристаллов и создания промежуточных слоев между кристаллом и теплоотводящим основанием, а также для разработки тепловых моделей при SPICE-моделировании мощных полевых транзисторов и диодных излучателей

Modeling the Subsurface Structure of Sunspots

While sunspots are easily observed at the solar surface, determining their subsurface structure is not trivial. There are two main hypotheses for the subsurface structure of sunspots: the monolithic model and the cluster model. Local helioseismology is the only means by which we can investigate subphotospheric structure. However, as current linear inversion techniques do not yet allow helioseismology to probe the internal structure with sufficient confidence to distinguish between the monolith and cluster models, the development of physically realistic sunspot models are a priority for helioseismologists. This is because they are not only important indicators of the variety of physical effects that may influence helioseismic inferences in active regions, but they also enable detailed assessments of the validity of helioseismic interpretations through numerical forward modeling. In this paper, we provide a critical review of the existing sunspot models and an overview of numerical methods employed to model wave propagation through model sunspots. We then carry out an helioseismic analysis of the sunspot in Active Region 9787 and address the serious inconsistencies uncovered by \citeauthor{gizonetal2009}~(\citeyear{gizonetal2009,gizonetal2009a}). We find that this sunspot is most probably associated with a shallow, positive wave-speed perturbation (unlike the traditional two-layer model) and that travel-time measurements are consistent with a horizontal outflow in the surrounding moat.Comment: 73 pages, 19 figures, accepted by Solar Physic

Organic chemistry. History and mutual relations of universities of Russia

© 2017, Pleiades Publishing, Ltd. The review describes the history of development of organic chemistry in higher schools of Russia over a period of 170 years, since the emergence of organic chemistry in our country till now