The Effect of Shadowing on Initial Conditions, Transverse Energy and Hard Probes in Ultrarelativistic Heavy Ion Collisions

The effect of shadowing on the early state of ultrarelativistic heavy ion collisions is investigated along with transverse energy and hard process production, specifically Drell-Yan, $J/\psi$, and $\Upsilon$ production. We choose several parton distributions and parameterizations of nuclear shadowing, as well as the spatial dependence of shadowing, to study the influence of shadowing on relevant observables. Results are presented for Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and Pb+Pb collisions at $\sqrt{s_{NN}} = 5.5$ TeV.Comment: Submitted to Phys. Rev.

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

Heavy Quark Photoproduction in Ultra-peripheral Heavy Ion Collisions

Heavy quarks are copiously produced in ultra-peripheral heavy ion collisions. In the strong electromagnetic fields, c c-bar and b b-bar are produced by photonuclear and two-photon interactions; hadroproduction can occur in grazing interactions. We present the total cross sections, quark transverse momentum and rapidity distributions, as well as the Q Q-bar invariant mass spectra from the three production channels. We consider AA and pA collisions at the Relativistic Heavy Ion Collider and Large Hadron Collider. We discuss techniques for separating the three processes and describe how the AA to pA production ratios might be measured accurately enough to study nuclear shadowing.Comment: Minor changes to satisfy referees and typo fixes; 52 pages including 17 figure

Hard Parton Rescatterings and Minijets in Nuclear Collisions at LHC

The average number of minijets and the corresponding transverse energy produced in heavy ion collisions are evaluated by including explicitly semi-hard parton rescatterings in the dynamics of the interaction. At the LHC semi-hard rescatterings have a sizable effect on global characteristics of the typical inelastic event. An interesting feature is that the dependence on the cutoff which separates soft and hard parton interactions becomes less critical after taking rescatterings into account.Comment: 14 pages, 3 figures. Enlarged discussion in sect.1 and 4; 1 figure added. To be published in Phys.Rev.

Experimental Study of Two-Phase Thermosyphons of the Thermoelectric Cooling Unit

Проведены экспериментальные исследования теплопередающей способности двухфазных термосифонов, заправленных фреоном 134А. Термосифоны изготовлены из нержавеющей стали, имеют длину 400 мм и внутренний диаметр 10,5 мм, протяженность зоны испарения составляла 200 мм, а длина конденсатора – 60 мм. Приведены данные измерений температурного состояния и теплопередающих характеристик термосифонов в зависимости от передаваемого теплового потока, угла наклона от вертикали и температуры теплоносителя системы теплоотводаExperimental studies of the heat transfer capacity of two- phase thermosiphons filled with Freon 134A have been carried out. Thermosyphons are made of stainless steel, have a length of 400 mm and an internal diameter of 10.5 mm, the length of the evaporation zone was 200 mm, and the length of the condenser was 60 mm.The data of measurements of the temperature state and heat transfer characteristics of thermosiphons depending on the transferred heat flux, the angle of inclination from the vertical and the temperature of the coolant of the heat removal system are give

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

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

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

The algorithm of providing medical preventive care of patients of risk group of development of malignant tumors of skin

The malignant skin tumors are neoplasms of visual localization and their diagnostic is extremely complicated because of diversity of their clinical forms. Among all skin malignant tumors, a melanoma holds a particular place being socially important problem because of high level of lethality related to significant metastatic potential of tumor and lower efficiency of therapy of later forms of disease. The article describes development and implementation of algorithm of rendering medical preventive care to patients of risk group of development of malignant skin tumor on the basis of investigation of actual epidemiological situation with morbidity of basalioma, melanoma, squamous cell carcinoma of skin in population of the Sverdlovsk region during 2000-2015 and detection of factors conditioning late diagnostic of malignant skin tumors. According to actual epidemiological data, an increasing of morbidity of both melanoma and other malignant skin tumors is observed in the Russian Federation on the whole and in the Sverdlovsk region. The article pays attention to that physicians of various specialties are to timely send patients of risk groups or with «suspicious» neoplasms to dermatovenerologist to specify character of neoplasm and to resolve issue concerning necessity of dispensary observation. The necessity is noted of tighter interaction of dermatoverologists and oncologists. Thereby, implementation of algorithm of rendering medical care to patients of risk groups of malignant skin tumors in the Sverdlovsk region promotes increasing of quality and accessibility of medical care to population, earlier detection of patients, decreasing of load of oncologic service by non-profile patients.Злокачественные опухоли кожи (ЗОК) относятся к новообразованиям визуальной локализации, дифференциальная диагностика их чрезвычайна сложна, что связано с многообразием клинических форм. Особое место среди всех ЗОК занимает меланома, являясь социально значимой проблемой в связи с высоким уровнем летальности, что обусловлено значительным метастатическим потенциалом опухоли и низкой эффективностью терапии поздних форм заболевания. В статье описаны разработка и внедрение алгоритма оказания медико-профилактической помощи пациентам групп риска по развитию ЗОК на основании изучения современной эпидемиологической ситуации по заболеваемости базалиомой, меланомой, плоскоклеточным раком кожи населения Свердловской области за период с 2000 по 2015 г., и выявления факторов, обусловливающих позднюю диагностику злокачественных опухолей кожи. Согласно эпидемиологическим данным, приведённым в статье, отмечается рост заболеваемости как меланомой, там и другими ЗОК за указанный период по Российской Федерации в целом и в Свердловской области. В статье авторы обращают внимание на то, что врачам различных специальностей необходимо своевременно направлять пациентов из групп риска или с «подозрительными» новообразованиями к врачу-дерматовенерологу для уточнения характера новообразования и решения вопроса о необходимости диспансерного наблюдения. Авторы указывают на необходимость более тесного взаимодействия врачей-дерматовенерологов и онкологов. Таким образом, внедрение алгоритма оказания медицинской помощи пациентам групп риска ЗОК в Свердловской области способствует повышению качества и доступности медицинской помощи населению, раннему выявлению больных, уменьшению нагрузки непрофильных больных на онкологическую службу