Measurement of the η\eta -η′\eta' mixing angle in π−\pi^{-} and K−K^{-} beams with GAMS-4π4\pi Setup

The results of mixing angle measurement for $\eta'$, $\eta$ mesons generated in charge exchange reactions with $\pi^{-}$ and $K^{-}$ beams are preseneted. When the $\eta'$, $\eta$ mesons are described in nonstrange(NS)--strange(S) quark basis the $\pi^{-}$ and $K^{-}$ beams allow to study $|\eta_{q}>$ and $|\eta_{s}>$ parts of the meson wave function. The cross section ratio at $t'=0$ (GeV/c)$^{2}$ in the $\pi^{-}$ beam is $R_{\pi}(\eta'/\eta)= 0.56 \pm 0.04$, results in mixing angle $\phi_{P} = (36.8 \pm 1.)^{o}$. For $K^{-}$ beam the ratio is $R_{K}(\eta'/\eta)= 1.30 \pm 0.16$. It was found that gluonium content in $\eta'$ is $\sin^{2}\psi_{G}= 0.15 \pm 0.06$. The experiment was carried out with GAMS-4$\pi$ Setup.Comment: 6 pages, 4 figures, 1 table, to be submitted in European physical journal C. Minor changes, the Bibliography extende

Contribution to the knowledge of Geminoppia (Acari, Oribatida, Oppiidae), with description of a new species from South Africa

A new species of the genus Geminoppia (Oribatida, Oppiidae) is described from moss of Hogsback State Forest, Eastern Cape Province, South Africa. Geminoppia amatholensis sp. n. differs from its related species Geminoppia maior comb. n. by the absence of discidium and the presence of very long notogastral seta h1. Summarized generic traits, an identification key, distribution and habitats of all known species of Geminoppia are presented

Study of the ηπo\eta\pi^o system in the mass range up to 1200 MeV

The reaction $\pi^-p \to \eta\pi^o n$ has been studied with GAMS-2000 spectrometer in the secondary 38 GeV/c $\pi^-$-beam of the IHEP U-70 accelerator. Partial wave analysis of the reaction has been performed in the $\eta\pi^o$ mass range up to 1200 MeV. The $a_0(980)$-meson is seen as a sharp peak in S-wave. The $t$-dependence of $a_0(980)$ production cross section has been studied. Dominant production of the $a_0(980)$ at a small transfer momentum $t$ confirms the hypothesis of Achasov and Shestakov about significant contribution of the $\rho_2$ exchange ($I^GJ^{PC}=1^+2^{--}$) in the mechanism of $a_0(980)$ meson production in $t$-channel of the reaction.Comment: 4 pages, 3 figures, talk given at HADRON'9

On the Surface Structure of Strange Superheavy Nuclei

Bound, strange, neutral superheavy nuclei, stable against strong decay, may exist. A model effective field theory calculation of the surface energy and density of such systems is carried out assuming vector meson couplings to conserved currents and scalar couplings fit to data where it exists. The non-linear relativistic mean field equations are solved assuming local baryon sources. The approach is calibrated through a successful calculation of the known nuclear surface tension.Comment: 12 pages, 9 figure

Разработка микронасосной системы для поддержки кровообращения

Introduction. Support systems currently used in modern cardiac surgery to provide partial or complete, permanent or temporary replacement of cardiac function are frequently characterized by large dimensions, thus requiring major surgical interventions. Low invasiveness can be ensured by reducing the size of the implanted part of such systems, allowing these devices to be inserted through the femoral artery.Aim. Development of a minimally invasive micropump system to support blood circulation.Materials and methods. Based on the analysis of implementation of micropump circulatory support systems (MCSS), the configuration, operational principles and main components of such a system were determined. When designing a micropump, as a unit defining the weight and size parameters of the entire system, numerical and experimental methods were used to optimize its flow path based on the condition of minimizing blood injury and thrombus formation. The lubrication and cooling system was developed by solving the thermodynamic problem of heat removal. The electronic control unit was developed on the basis of accumulated experience in the design and operation of control units for circulatory support systems.Results. A micropump with a diameter of 6.5 mm and a length of 43 mm with the required hydro- and hemodynamic parameters was designed. The device ensures minimal trauma and thrombus formation. The main MCSS parameters, as well as its main components (electric drives, lubrication and cooling systems), were defined. The configuration and operational principles of the electronic control unit (ECU), consisting in a microprocessor-based control system with feedback, were developed. The ECU built-in software manages the rotational speed of the electric drives of the micropump and coolant supply pump in the required range. In addition, the software is used to measure, display and register the MCSS operational parameters, as well as to monitor their operation in the required ranges and to exchange data between the ECU and the PC.Conclusion. All the necessary documentation for the MCSS nodes and components was prepared. These nodes and components ensure the hydro- and hemodynamic parameters required for the use of the developed minimally invasive micropump system. Future work will address the stages of MCSS assembly and debugging.Введение. В современной кардиохирургии для обеспечения частичной или полной, постоянной или временной замены функции сердца применяются системы поддержки, имеющие размеры, требующие проведения серьезной хирургической операции. Для обеспечения малой инвазивности требуется существенно уменьшить размеры имплантируемой части системы, что позволит вводить эти устройства через бедренную артерию.Цель работы. Разработка малоинвазивной микронасосной системы для поддержки кровообращения.Материалы и методы. На основе анализа технологии применения системы поддержки кровообращения (МСПК) разработан ее состав, принцип работы, спроектированы основные ее узлы и элементы. При проектировании микронасоса как узла, определяющего массогабаритные параметры всей системы, используются численные и экспериментальные методы оптимизации его проточной части из условия минимизации травмы крови и тромбообразования. При разработке системы смазки и охлаждения решалась термодинамическая задача по обеспечению отвода тепла. Электронный блок управления разработан на основании накопленного опыта проектирования и эксплуатации блоков управления клинически применяемых систем вспомогательного кровообращения.Результаты. Спроектирован микронасос диаметром 6,5 мм и длиной 43 мм с требуемыми гемо- и гидродинамическими параметрами, обеспечивающий минимальную травму и тромбообразование. Определены основные параметры и спроектированы узлы и элементы МСПК (электроприводы, система смазки и охлаждения). Разработан состав и принцип работы электронного блока управления (ЭБУ), который представляет собой микропроцессорную систему управления МСПК с обратной связью. Встроенное программное обеспечение ЭБУ позволяет управлять частотой вращения электроприводов микронасоса и насоса подачи охлаждающей жидкости в требуемом диапазоне, измерять, отображать, регистрировать режимные параметры работы МСПК, а также осуществлять контроль их работы в требуемых диапазонах, обмениваться данными между ЭБУ и компьютером.Заключение. Подготовлена документация на узлы и элементы МСПК, обеспечивающие требуемые гидро- и гемодинамические параметры, необходимые для применения микронасосной малоинвазивной системы, что позволяет перейти к сборке и отладке узлов и элементов МСПК в целом

Optimization of the drainage system of overburden dumps using geofiltration modeling

The article describes the assessment of the predicted water flows at the site of the projected rock dumps, which was carried out using geofiltration modeling. When developing the model, we used actual data on capacities, filtration coefficients and water capacity, roof and sole marks of the selected aquifers, precipitation infiltration, as well as the projected dumps are located on the slope surfac

Measurement of the K+→μ+νμγK^+\rightarrow{\mu^+}{\nu_{\mu}}{\gamma} decay form factors in the OKA experiment

A precise measurement of the vector and axial-vector form factors difference $F_V-F_A$ in the $K^+\rightarrow{\mu^+}{\nu_{\mu}}{\gamma}$ decay is presented. About 95K events of $K^+\rightarrow{\mu^+}{\nu_{\mu}}{\gamma}$ are selected in the OKA experiment. The result is $F_V-F_A=0.134\pm0.021(stat)\pm0.027(syst)$. Both errors are smaller than in the previous $F_V-F_A$ measurements.Comment: 9 pages, 8 figure