86 research outputs found
Electron-positron pairs in hot plasma of accretion column in bright X-ray pulsars
The luminosity of X-ray pulsars powered by accretion onto magnetized neutron
stars covers a wide range over a few orders of magnitude. The brightest X-ray
pulsars recently discovered as pulsating ultraluminous X-ray sources reach
accretion luminosity above which exceeds the
Eddington value more than by a factor of ten. Most of the energy is released
within small regions in the vicinity of magnetic poles of accreting neutron
star - in accretion columns. Because of the extreme energy release within a
small volume accretion columns of bright X-ray pulsars are ones of the hottest
places in the Universe, where the internal temperature can exceed 100 keV.
Under these conditions, the processes of creation and annihilation of
electron-positron pairs can be influential but have been largely neglected in
theoretical models of accretion columns. In this letter, we investigate
properties of a gas of electron-positron pairs under physical conditions
typical for accretion columns. We argue that the process of pairs creation can
crucially influence both the dynamics of the accretion process and internal
structure of accretion column limiting its internal temperature, dropping the
local Eddington flux and increasing the gas pressure.Comment: 5 pages, 5 figures, accepted for publication in MNRAS Letter
On the Possible Enhancement of the Magnetic Field by Neutrino Reemission Processes in the Mantle of a Supernova
URCA neutrino reemission processes under the conditions in the mantle of a
supernova with a strong toroidal magnetic field are investigated. It is shown
that parity violation in these processes can be manifested macroscopically as a
torque that rapidly spins up the region of the mantle occupied by such a field.
Neutrino spin-up of the mantle can strongly affect the mechanism of further
generation of the toroidal field, specifically, it can enhance the field in a
small neighborhood of the rigid-body-rotating core of the supernova remnant.Comment: 8 pages, late
Efficiency of Electron-Positron Pair Productionby Neutrino Flux from Accretion Disk of a Kerr Black Hole
Dominant processes of neutrino production and neutrino-induced \ep-pair
production are examined in the model of a disk hyper-accreting onto a Kerr
black hole. The efficiency of plasma production by a neutrino flux from the
disk, obtained for the both cases of presence and absence of a magnetic field,
is found to be no more than several tenths of percent and, therefore, not
enough for the origin of cosmological gamma-ray bursts.Comment: 8 pages, 1 figur
Minimally invasive surgery parenchymal cysts abdominal children
Retrospectively and prospectively studied 53 clinical cases of surgical treatment of cystic formations of parenchpal abdominal organs in children. Experience in treatment of cysts various minimally invasive techniques. The most efficient and optimal results are achieved with laparoscopic fenestration of cysts in conjunction with argon plasma deepitelizatsii inner lining.Ретроспективно и проспективно изучено 53 клинических случая оперативного лечения кистозных образований паренхиматозных органов брюшной полости у детей. Представлен опыт лечения кист различными малоинвазивными методиками. Наиболее эффективные и оптимальные результаты достигнуты при лапароскопической фенестрации кист в сочетании с аргоноплазменной деэпителизацией внутренней выстилки
Benign bone neoplasm in children in the Sverdlovsk region
The article presents a retrospective analysis of patients (children) with benign bone tumors who have received treatment in the Traumathology and Orthopaedics Department of the SAIH "Regional Children's Clinical Hospital" for the last five years, in particular: osteochondroma, osteoidosteoma, chondroma and tumors with intraossal growth. The article presents the options for therapeutic and tactical decisions, various options for bone grafting in 446 patients as well as the long-term results of the treatment.Представлен ретроспективный анализ детей, пролеченных в травматолого-ортопедическом отделении ГАУЗ СО «Областной детской клинической больницы» с доброкачественными образованиями костей за последние пять лет, в частности: остеохондромы, остеоид-остеомы, хондромы и опухоли с интраоссальным ростом. В статье приведены варианты лечебно- тактических решений, различные варианты пластики костной ткани у 446 пациентов, а также отдаленные результаты проведенного лечения
Surgical managment of liver tumors in children
The article presents 23 years’ experience of surgical treatment of liver tumors in pediatric patients in the Sverdlovsk region. Diagnostic methods are highlighted, significance of prophylactic ultrasound examination of children is defined. Options of surgical treatment are noticed, results of mono- and multidisciplinary approach of the cooperative team: pediatric surgeon, transplant surgeon-hepatologist and pediatric cardiac surgeon.В статье представлен 23-летний опыт лечения опухолей печени у детей в Свердловской области. Освещены методы диагностики, определена значимость профилактического сонографического исследования детей. Отражены варианты оперативно-тактических решений, результаты моно- и мультидисциплинарного лечения объединенной бригады: детский хирург, хирург гепатолог-трансплантолог и детский кардиохирург
Clinical-endoscopic ahd morphological characteristics of ectopic in wall of stomach pancreas in children
The result of clinical-morphological examination and treatment of 188 children with ectopic in wall of stomach pancreas is showed. The endoscopic criteria of diagnostics are presented. Authors propose the classification of ectopic pancreas macroscopic kinds. The morphologic image of this malformation is described in details. The kinds of histological structure and forms of ectopic pancreas layer-by-layer localization are determined.Представлен результат клинико-морфологического обследования и лечения 188 детей с зктопией поджелудочной железы в стенку желудка Приведены эндоскопические критерии диагностики и предложена рабочая классификация макроскопических типов ЭПЖ. Подробно описана морфологическая картина данного порока развития. Установлены варианты гистостроения и формы послойной локализации ЗПЖ
Features of diagnostics and surgical treatment of ovarian tumors in children
The purpose of current work was to assess prognostically significant laboratory parameters in patients with ovarian tumors, as well as to determine optimal types of surgical treatment.Целью работы являлись оценка прогностически значимых лабораторных показателей, а также определение наиболее оптимальных видов хирургического лечения пациенток с опухолями яичников
- …