Formation of "Lightnings" in a Neutron Star Magnetosphere and the Nature of RRATs

The connection between the radio emission from "lightnings" produced by the absorption of high-energy photons from the cosmic gamma-ray background in a neutron star magnetosphere and radio bursts from rotating radio transients (RRATs) is investigated. The lightning length reaches 1000 km; the lightning radius is 100 m and is comparable to the polar cap radius. If a closed magnetosphere is filled with a dense plasma, then lightnings are efficiently formed only in the region of open magnetic field lines. For the radio emission from a separate lightning to be observed, the polar cap of the neutron star must be directed toward the observer and, at the same time, the lightning must be formed. The maximum burst rate is related to the time of the plasma outflow from the polar cap region. The typical interval between two consecutive bursts is ~100 s. The width of a single radio burst can be determined both by the width of the emission cone formed by the lightning emitting regions at some height above the neutron star surface and by a finite lightning lifetime. The width of the phase distribution for radio bursts from RRATs, along with the integrated pulse width, is determined by the width of the bundle of open magnetic field lines at the formation height of the radio emission. The results obtained are consistent with the currently available data and are indicative of a close connection between RRATs, intermittent pulsars, and extreme nullers.Comment: 24 pages, no figures, references update

Carbon Supported Polyaniline as Anode Catalyst: Pathway to Platinum-Free Fuel Cells

The effectiveness of carbon supported polyaniline as anode catalyst in a fuel cell (FC) with direct formic acid electrooxidation is experimentally demonstrated. A prototype FC with such a platinum-free composite anode exhibited a maximum room-temperature specific power of about 5 mW/cm2Comment: 11 pages, 3 Postscript figures, atricle tex styl

Технологические и реологические основы формования макаронных изделий в узлах прессования с предварительным двухступенчатым уплотнением, пластификацией и разогревом теста

One of efficient directions for pasta press designs modernization is installation of special conical-andcylindrical inserts in the pre-matrix space and matrix wells in front of the dies having, like Venturi tubes, narrowing zones (convergent), expansion (divergent) and a cylindrical path located between them. However, rheological aspects of such method of forming tool modernizing in relation to pasta presses have not been studied, recommendations for structural elements calculation and design have not been developed. All this is a significant obstacle for using the method in engineering and industrial practice. The research purpose is to develop rheological models the pasta dough flow in the conical-cylindrical channels of convergent-divergent inserts and to evaluate with their help the impact of structural dimensions and rheological properties on resistance to pasta dough flow. Pasta dough was considered as a rheological complex nonlinearly viscous plastic material. In technical calculations contribution of shear strength was neglected and a rheological analysis was performed using the Oswald-de-Ville power law equation. Analytical dependences obtained make it possible to calculate the pressure drops in the convergent-divergent insert and its elements. Numerical modeling was performed and calculated data were obtained regarding the impact of dimensions of structural elements of the insert and rheological parameters of pasta dough on its resistance to viscous flow. The results obtained can form the basis of engineering and technological calculations in design of convergent-divergent inserts for laboratory and industrial pasta presses.Одним из эффективных направлений модернизации конструкций макаронных прессов является установка в предматричном пространстве и колодцах матрицы перед фильерами специальных коническо-цилиндрических вставок, имеющих, подобно трубкам Вентури, зоны сужения (конфузор), расширения (диффузор) и расположенный между ними цилиндрический поясок. Однако реологические аспекты такого метода модернизации формообразующей оснастки применительно к макаронным прессам не изучены, рекомендации по расчету и проектированию конструктивных элементов не разработаны. Все это является существенным препятствием для использования метода в инженерной и производственной практике. Цель работы – разработка реологических моделей течения макаронного теста в коническо-цилиндрических каналах конфузорно-диффузорныхвставок и оценка с их помощью влияния конструктивных размеров и показателей реологических свойств на сопротивление течению макаронного теста. Макаронное тесто рассматривали как реологически сложный, нелинейно вязко-пластичный материал. При технических расчетах вкладом сдвиговой прочности пренебрегали и осуществляли реологический анализ с использованием степенного реологического уравнения Освальда-де-Вила. Получены аналитические зависимости, позволяющие производить расчет перепадов давления в конфузорно-диффузорной вставке и ее элементах. Произведено численное моделирование и получены расчетные данные по влиянию размеров конструктивных элементов вставки и расхода макаронного теста через вставку на сопротивление его вязкому течению. Полученные результаты могут составить основу инженерно-технологических расчетов при проектировании конфузорно-диффузорных вставок для лабораторных и промышленных макаронных прессов

Реологическое моделирование процессов течения макаронного теста в каналах конфузорно-диффузорных вставок формующих матриц

One of efficient directions for pasta press designs modernization is installation of special conical-and-cylindrical inserts in the matrix wells in front of the dies having, like Venturi tubes, narrowing zones (convergent), expansion (divergent) and a cylindrical path located between them. However, rheological aspects of such method of forming tool modernizing in relation to pasta presses have not been studied, recommendations for structural elements calculation and design have not been developed. All this is a significant obstacle for using the method in engineering and industrial practice. The research purpose is to develop rheological models the pasta dough flow in the conical-cylindrical channels of convergent-divergent inserts and to evaluate with their help the impact of structural dimensions and rheological properties on resistance to pasta dough flow. Pasta dough was considered as a rheological complex nonlinearly viscous plastic material. In technical calculations contribution of shear strength was neglected and a rheological analysis was performed using the Oswald-de-Vila power law equation. Analytical dependences obtained make it possible to calculate the pressure drops in the convergent-divergent insert and its elements. Numerical modeling was performed and calculated data were obtained regarding the impact of dimensions of structural elements of the insert and rheological parameters of pasta dough on its resistance to viscous flow. The results obtained can form the basis of engineering and technological calculations in design of convergent-divergent inserts for laboratory and industrial matrices of pasta presses.Одним из эффективных направлений модернизации конструкций макаронных прессов является установка в колодцах матрицы перед фильерами специальных коническо- цилиндрических вставок, имеющих, подобно трубкам Вентури, зоны сужения (конфузор), расширения (диффузор) и расположенный между ними цилиндрический поясок. Однако реологические аспекты такого метода модернизации формообразующей оснастки применительно к макаронным прессам не изучены, рекомендации по расчету и проектированию конструктивных элементов не разработаны. Все это является существенным препятствием для использования метода в инженерной и производственной практике. Цель работы – разработка реологических моделей течения макаронного теста в коническо-цилиндрических каналах конфузорно-диффузорных вставок и оценка с их помощью влияния конструктивных размеров и показателей реологических свойств на сопротивление течению макаронного теста. Макаронное тесто рассматривали как реологически сложный, нелинейно вязко-пластичный материал. При технических расчетах вкладом сдвиговой прочности пренебрегали и осуществляли реологический анализ с использованием степенного реологического уравнения Освальда–де–Вила. Получены аналитические зависимости, позволяющие производить расчет перепадов давления в конфузорно-диффузорной вставке и ее элементах. Произведено численное моделирование и получены расчетные данные по влиянию размеров конструктивных элементов вставки и расхода макаронного теста через вставку на сопротивление его вязкому течению. Полученные результаты могут составить основу инженерно технологических расчетов при проектировании конфузорно-диффузорных вставок для лабораторных и промышленных матриц макаронных прессов

ORGAN-SPARING TREATMENT IN PATIENTS WITH SQUAMOUS CELL CARCINOMA OF THE ANAL CANAL

Objective: to improve the results of treatment in patients with squamous cell carcinoma of the anal canal, by creating a new combination treatment option, and to increase the rate of organ-sparing treatment.Subjects and methods. A new combination treatment option for squamous cell carcinoma of the anal canal was created, which involved a combination of radiotherapy and a multiple radio modification program (ultrahigh-frequency (UHF) hyperthermia and local metronidazole (MZ) injection and systemic polychemotherapy) (RF patent No. 2427399 “A treatment option for squamous cell carcinoma of the anal canal” registered on 27 August 2011). To evaluate the created treatment option, the latter was analyzed in 157 patients with Т1–4N0–3M0 squamous cell carcinoma of the anal canal, who had been treated in 1990 to 2012. In 22 patients, radiotherapy was performed in combination with 3–5 sessions of local UHF hyperthermia (thermoradiotherapy (TRT)); 88 patients received the latter in combination with polychemotherapy (thermoradiochemotherapy (TRCT)); in addition to TRCT, 47 patients used MZ (TRCT + MZ).Results. In the TRT, TRCT, and TRCT + MZ groups, organ-sparing treatment was performed in 11 (50 %), 71 (80.7 %), and 44 (93.6 %) patients, respectively. In these groups, the median follow-up was 18.6; 51.7, and 15.5 months, respectively. In the 3 groups, the three-year overall survival rates were 71.4; 90.0, and 96.3 % and the three-year relapse free survival rates were 46.7; 60.6, and 75.0 %, respectively.Conclusion. The created combination thermochemoradiotherapy involving a polymer combination with MZ (TRCT + MZ) makes it possible to achieve organ-sparing treatment in 93.6 % of the patients and to slightly improve 3-year overall and relapse-free survival rates in patients with squamous cell carcinoma of the anal canal who have received organ-sparing treatment although there is only a tendency for statistical survival difference in this patient group

NEOADJUVANT THERMOCHEMORADIOTHERAPY USING INTRARECTAL 5-FLUORURACIL IN COMBINED TREATMENT OF RECTAL CANCER

Safety and efficacy of intrarectal 5-fluoruracil in combined treatment of localized rectal cancer was investigated in this article. Our data supports safety, economical efficacy and simplicity of use of this method. It improves sphincter preservation rate in patients with distal rectal cancer, does not increase surgical mortality and morbidity, leads to high tumor regression rate, improves local control and decreases distant failure rate

РАДИОРЕЗИСТЕНТНОСТЬ ОПУХОЛИ И ПУТИ ЕЕ ПРЕОДОЛЕНИЯ (ОБЗОР ЛИТЕРАТУРЫ)

Presented article is a review of domestic and foreign literature on the application of radiomodifying drugs with electron-affinic properties (metronidazole and its derivatives) with the aim of increasing the effectiveness of radiation therapy. The mechanism of action and properties of the electron-affinic drugs of is described. Special attention is paid to the creation of a new medicinal form of metronidazole with the hydrogel-based biopolymer and its inclusion in combined treatment of resectable and locally advanced rectal cancer.Представлен обзор отечественной и зарубежной литературы по применению радиомодификаторов, обладающих электронакцепторными свойствами (метронидазол (МЗ) и его производные) с целью повышения эффективности лучевой терапии. Рассмотрен механизм действия и характеристика препаратов электронакцепторной группы. Особо внимание обращено на создание новой лечебной формы МЗ в виде гидрогеля на основе биополимера альгината натрия и включение его в комплексное лечение операбельного и местнораспространенного рака прямой кишки

Magnetic Field Generation in Stars

Enormous progress has been made on observing stellar magnetism in stars from the main sequence through to compact objects. Recent data have thrown into sharper relief the vexed question of the origin of stellar magnetic fields, which remains one of the main unanswered questions in astrophysics. In this chapter we review recent work in this area of research. In particular, we look at the fossil field hypothesis which links magnetism in compact stars to magnetism in main sequence and pre-main sequence stars and we consider why its feasibility has now been questioned particularly in the context of highly magnetic white dwarfs. We also review the fossil versus dynamo debate in the context of neutron stars and the roles played by key physical processes such as buoyancy, helicity, and superfluid turbulence,in the generation and stability of neutron star fields. Independent information on the internal magnetic field of neutron stars will come from future gravitational wave detections. Thus we maybe at the dawn of a new era of exciting discoveries in compact star magnetism driven by the opening of a new, non-electromagnetic observational window. We also review recent advances in the theory and computation of magnetohydrodynamic turbulence as it applies to stellar magnetism and dynamo theory. These advances offer insight into the action of stellar dynamos as well as processes whichcontrol the diffusive magnetic flux transport in stars.Comment: 41 pages, 7 figures. Invited review chapter on on magnetic field generation in stars to appear in Space Science Reviews, Springe