Hard X-ray Bursts Recorded by the IBIS Telescope of the INTEGRAL Observatory in 2003-2009

To find X-ray bursts from sources within the field of view of the IBIS/INTEGRAL telescope, we have analysed all the archival data of the telescope available at the time of writing the paper (the observations from January 2003 to April 2009). We have detected 834 hard (15-25 keV) X-ray bursts, 239 of which were simultaneously recorded by the JEM-X/INTEGRAL telescope in the standard X-ray energy range. More than 70% of all bursts (587 events) have been recorded from the well-known X-ray burster GX 354-0. We have found upper limits on the distances to their sources by assuming that the Eddington luminosity limit was reached at the brightness maximum of the brightest bursts.Comment: 18 pages, 2 figures, 2 table

Nontrivial dependence of dielectric stiffness and SHG on dc bias in relaxors and dipole glasses

Dielectric permittivity and Second Harmonic Generation (SHG) studies in the field-cooled mode show a linear dependence of dielectric stiffness (inverse dielectric permittivity) on dc bias in PMN-PT crystals and SHG intensity in KTaO$_{3}$:Li at small Li concentrations. We explain this unusual result in the framework of a theory of transverse, hydrodynamic-type, instability of local polarization.Comment: 5 figure

Вычисление живучести транспортных машин

The article deals with multi criteria problem of the mechanical system in case of destruction of some of its elements. As an example, a dynamic contact between the gas-turbine locomotive GT1-h with an obstacle is considered. The purpose of this work is to obtain the information about the limit state of the locomotive cabin in terms of the parameters of the obstacles and the speed of the locomotive movement. This information is necessary for the design calculations, and is presented in a form suitable for engineering analysis. In three-dimensional parameter, space external impacts acting on the cab is defined as a hypersurface, which indicates that the structure is in the limit state. Such a surface determines the survivability of vehicles and specifies the safe operation of the locomotive cab in case of a collision with an obstacle. The calculations conducted have shown a significant effect of the area and location of load on the cabin survivability. It was concluded that it is necessary to strengthen the cabin to ensure the safety of the crew and the dashboard of the cab in case of an emergent collision with the obstacle of large mass and a high speed.Рассматривается многокритериальная задача поведения механической системы при разрушении отдельных элементов. В качестве примера анализируется внештатная ситуация динамического взаимодействия газотурбовоза ГТ1-h с препятствием. Цель работы состоит в получении информации о предельном состоянии кабины локомотива в зависимости от параметров препятствия и скорости движения состава. Данная информация необходима при выполнении проектных расчетов и представлена в виде, удобном для инженерного анализа. В трехмерном пространстве параметров внешнего воздействия на кабину построена поверхность перехода конструкции в предельное состояние. Такая поверхность ограничивает область безопасной эксплуатации кабины при случайном столкновении с препятствием. В результате проведенных расчетов выявлено существенное влияние площади и места приложения нагрузки на несущую способность кабины. Дано заключение о необходимости усиления кабины для обеспечения безопасности экипажа и приборной части при несанкционированной встрече с препятствием значительной массы и нарушении скоростного режима

Вычисление живучести транспортных машин

The article deals with multi criteria problem of the mechanical system in case of destruction of some of its elements. As an example, a dynamic contact between the gas-turbine locomotive GT1-h with an obstacle is considered. The purpose of this work is to obtain the information about the limit state of the locomotive cabin in terms of the parameters of the obstacles and the speed of the locomotive movement. This information is necessary for the design calculations, and is presented in a form suitable for engineering analysis. In three-dimensional parameter, space external impacts acting on the cab is defined as a hypersurface, which indicates that the structure is in the limit state. Such a surface determines the survivability of vehicles and specifies the safe operation of the locomotive cab in case of a collision with an obstacle. The calculations conducted have shown a significant effect of the area and location of load on the cabin survivability. It was concluded that it is necessary to strengthen the cabin to ensure the safety of the crew and the dashboard of the cab in case of an emergent collision with the obstacle of large mass and a high speed.Рассматривается многокритериальная задача поведения механической системы при разрушении отдельных элементов. В качестве примера анализируется внештатная ситуация динамического взаимодействия газотурбовоза ГТ1-h с препятствием. Цель работы состоит в получении информации о предельном состоянии кабины локомотива в зависимости от параметров препятствия и скорости движения состава. Данная информация необходима при выполнении проектных расчетов и представлена в виде, удобном для инженерного анализа. В трехмерном пространстве параметров внешнего воздействия на кабину построена поверхность перехода конструкции в предельное состояние. Такая поверхность ограничивает область безопасной эксплуатации кабины при случайном столкновении с препятствием. В результате проведенных расчетов выявлено существенное влияние площади и места приложения нагрузки на несущую способность кабины. Дано заключение о необходимости усиления кабины для обеспечения безопасности экипажа и приборной части при несанкционированной встрече с препятствием значительной массы и нарушении скоростного режима

Impact-parameter dependent nuclear parton distribution functions: EPS09s and EKS98s and their applications in nuclear hard processes

We determine the spatial (impact parameter) dependence of nuclear parton distribution functions (nPDFs) using the $A$-dependence of the spatially independent (averaged) global fits EPS09 and EKS98. We work under the assumption that the spatial dependence can be formulated as a power series of the nuclear thickness functions $T_A$. To reproduce the $A$-dependence over the entire $x$ range we need terms up to $[T_A]^4$. As an outcome, we release two sets, EPS09s (LO, NLO, error sets) and EKS98s, of spatially dependent nPDFs for public use. We also discuss the implementation of these into the existing calculations. With our results, the centrality dependence of nuclear hard-process observables can be studied consistently with the globally fitted nPDFs for the first time. As an application, we first calculate the LO nuclear modification factor $R^{1jet}_{AA}$ for primary partonic-jet production in different centrality classes in Au+Au collisions at RHIC and Pb+Pb collisions at LHC. Also the corresponding central-to-peripheral ratios $R_{CP}^{1jet}$ are studied. We also calculate the LO and NLO nuclear modification factors for single inclusive neutral pion production, $R_{dAu}^{\pi^0}$, at mid- and forward rapidities in different centrality classes in d+Au collisions at RHIC. In particular, we show that our results are compatible with the PHENIX mid-rapidity data within the overall normalization uncertainties given by the experiment. Finally, we show our predictions for the corresponding modifications $R_{pPb}^{\pi^0}$ in the forthcoming p+Pb collisions at LHC.Comment: 36 page

Dynamics of Hot Bulk QCD Matter: from the Quark-Gluon Plasma to Hadronic Freeze-Out

We introduce a combined macroscopic/microscopic transport approach employing relativistic hydrodynamics for the early, dense, deconfined stage of the reaction and a microscopic non-equilibrium model for the later hadronic stage where the equilibrium assumptions are not valid anymore. Within this approach we study the dynamics of hot, bulk QCD matter, which is expected to be created in ultra-relativistic heavy ion collisions at the SPS, the RHIC and the LHC. Our approach is capable of self-consistently calculating the freeze-out of the hadronic system, while accounting for the collective flow on the hadronization hypersurface generated by the QGP expansion. In particular, we perform a detailed analysis of the reaction dynamics, hadronic freeze-out, and transverse flow.Comment: 55 pages, 15 figure

Hard X-ray Bursts Detected by the IBIS Telescope Onboard the INTEGRAL Observatory in 2003-2004

All of the observations performed with the IBIS telescope onboard the INTEGRAL observatory during the first one and a half years of its in-orbit operation (from February 10, 2003, through July 2, 2004) have been analyzed to find X-ray bursts. IBIS/ISGRI detector lightcurves total count rate in the energy range 15-25 keV revealed 1077 bursts of durations from ~5 to ~500 s detected with a high statistical significance (only one event over the entire period of observations could be detected by a chance with a probability of 20%). Apart from the events associated with cosmic gamma-ray bursts (detected in the field of view or passed through the IBIS shield), solar flares, and activity of the soft gamma repeater SGR1806-20, we were able to localize 105 bursts and, with one exception, to identify them with previously known persistent or transient X-ray sources (96 were identified with known X-ray bursters). In one case, the burst source was a new burster in a low state. We named it IGR J17364-2711. Basic parameters of the localized bursts and their identifications are presented in the catalog of bursts. Curiously enough, 61 bursts were detected from one X-ray burster - GX 354-0. The statistical distributions of bursts in duration, maximum flux, and recurrence time have been analyzed for this source. Some of the bursts observed with the IBIS/ISGRI telescope were also detected by the JEM-X telescope onboard the INTEGRAL observatory in the standard X-ray energy range 3-20 keV.Comment: 30 pages, 9 figure

Circularly polarized electroluminescence from silicon nanostructures heavily doped with boron

The circularly polarized electroluminescence (CPEL) from silicon nanostructures which are the p-type ultra-narrow silicon quantum well (Si-QW) confined by {\delta}-barriers heavily doped with boron, 5 10^21 cm^-3, is under study as a function of temperature and excitation levels. The CPEL dependences on the forward current and temperature show the circularly polarized light emission which appears to be caused by the exciton recombination through the negative-U dipole boron centers at the Si-QW {\delta}-barriers interface