Second harmonic electromagnetic emission of a turbulent magnetized plasma driven by a powerful electron beam

The power of second harmonic electromagnetic emission is calculated for the case when strong plasma turbulence is excited by a powerful electron beam in a magnetized plasma. It is shown that the simple analytical model of strong plasma turbulence with the assumption of a constant pump power is able to explain experimentally observed bursts of electromagnetic radiation as a consequence of separate collapse events. It is also found that the electromagnetic emission power calculated for three-wave interaction processes occurring in the long-wavelength part of turbulent spectrum is in order-of-magnitude agreement with experimental results

Homology class of a Lagrangian Klein bottle

It is shown that an embedded Lagrangian Klein bottle represents a non-trivial mod 2 homology class in a compact symplectic four-manifold $(X,\omega)$ with $c_1(X)\cdot[\omega]>0$. (In versions 1 and 2, the last assumption was missing. A counterexample to this general claim and the first proof of the corrected result have been found by Vsevolod Shevchishin.) As a corollary one obtains that the Klein bottle does not admit a Lagrangian embedding into the standard symplectic four-space.Comment: Version 3 - completely rewritten to correct a mistake; Version 4 - minor edits, added references; AMSLaTeX, 6 page

Strain-Hardening Stages and Structure Evolution in Pure Niobium and Vanadium upon High Pressure Torsion

High pressure torsion (HPT) is one of the ways to form nanostructured materials with high strength properties. However, HPT hardening mechanisms vary from material to material and are poorly understood for some BCC metals, particularly niobium and vanadium. This work aims to identify strain hardening stages for Nb and V metals during HPT. Two approaches have been used to identify the deformation stages during high pressure torsion. The approaches are based on the application of a "piecewise" model, taking into account the different deformation mechanisms that determine the type of the forming structure, and on the analysis of the hardness vs. true strain dependence according to the $H$$-$${e}^{0.5}$ law. We compared the identified stages with the results of the electron microscopic study of the structure. Both models describe well the structural changes observed microscopically in HPT-deformed niobium. However, we have shown that only the piecewise model gives an adequate description of the stages of structure development in vanadium. We have provided an explanation for the observed difference in the behavior of niobium and vanadium upon HPT.Comment: 21 pages, 9 figures, 1 tabl

Microstructure and mechanical properties of V-4Ti-4Cr alloy as a function of the chemical heat treatment regimes

The regularities of the formation of a heterophase structure and mechanical properties of V–4Ti–4Cr alloy as a function of thermomechanical and chemical heat treatments are studied. The regimes of thermomechanical treatment which provide the formation of a heterophase structure with a homogeneous volume distribution of oxycarbonitride nanoparticles with a size of about 10 nm and an increase in the volume content and thermal stability of this phase and which provide an increase in the temperature of alloy recrystallization are developed. The formation of the heterophase structure results in a substantial (up to 70%) increase in the short-term high-temperature strength of the alloy at T = 800°C. The increase in the strength is achieved while keeping a rather high level of plasticity

Estimated Inpatient Hospital Stay in Individual Wards: Guidelines on Radiation Safety after Radioiodine Therapy

Radionuclide therapy safety requirements are regulated by the Russian Radiation Safety Standards (RRSS), which state the maximum allowed radionuclide activity in the body and the equivalent dose rate (EDR) of gamma radiation. Therefore, it is necessary to estimate the time of an inpatient hospital stay in specially designed radionuclide therapy wards. The article presents the findings of individual 131I biokinetics studies in 64 patients admitted to radioiodine therapy of thyrotoxicosis and differentiated thyroid cancer. We developed a method to calculate the time interval to reach the EDR of 20μSv/h and the recommended EDR of 3 and 0.3μSv/h for adults and children, respectively. It is based on the measurement of the 131I excretion constant. Keywords: Radioiodine therapy, Radiation safety, Guidelin

CEM03 and LAQGSM03 - new modeling tools for nuclear applications

An improved version of the Cascade-Exciton Model (CEM) of nuclear reactions realized in the code CEM2k and the Los Alamos version of the Quark-Gluon String Model (LAQGSM) have been developed recently at LANL to describe reactions induced by particles and nuclei for a number of applications. Our CEM2k and LAQGSM merged with the GEM2 evaporation/fission code by Furihata have predictive powers comparable to other modern codes and describe many reactions better than other codes; therefore both our codes can be used as reliable event generators in transport codes for applications. During the last year, we have made a significant improvements to the intranuclear cascade parts of CEM2k and LAQGSM, and have extended LAQGSM to describe photonuclear reactions at energies to 10 GeV and higher. We have produced in this way improved versions of our codes, CEM03.01 and LAQGSM03.01. We present a brief description of our codes and show illustrative results obtained with CEM03.01 and LAQGSM03.01 for different reactions compared with predictions by other models, as well as examples of using our codes as modeling tools for nuclear applications.Comment: 12 pages, 10 figures, to be published in Journal of Physics: Conference Series: Proc. Europhysics Conf. on New Trends in Nuclear Physics Applications and Technologies (NPDC19), Pavia, Italy, September 5-9, 200

Armor Steel of Medium Tanks and Self-Propelled Artillery Installations of the Red Army in the Years of the Great Patriotic War

The article presents the results of a study of the metallurgical characteristics of the armor of self-propelled artillery installations SU-122, SU-85, SU-100, produced at Uralmash, and T-34 tanks, produced by the Kharkov plant No. 183 and the Stalingrad tractor plant. The chemical composition, hardness, the nature of fractures, and the microstructure of the steel of individual armor elements of the investigated objects have been established. The data obtained, in general, correspond to the brand parameters of 8C armor steel. The effectiveness of portable devices for non-destructive testing of metals is shown when working at museum expositions.В статье представлены результаты исследования металловедческих характеристик брони самоходных артиллерийских установок СУ-122, СУ-85, СУ-100, произведенных на Уралмаше, и танков Т-34, произведенных Харьковским заводом №183 и Сталинградским тракторным заводом. Установлены химический состав, твердость, характер изломов, микроструктура стали отдельных элементов бронирования исследованных объектов. Полученные данные в целом соответствуют марочным параметрам броневой стали 8С. Показана эффективность переносных приборов неразрушающего контроля металлов при работе на музейных экспозициях

СЛУЧАЙ УСПЕШНОГО ХИРУРГИЧЕСКОГО ЛЕЧЕНИЯ ПАЦИЕНТА С ПОЛНЫМ ТРАВМАТИЧЕСКИМ ОТРЫВОМ МОШОНКИ И КОЖНЫХ ПОКРОВОВ ПОЛОВОГО ЧЛЕНА В УСЛОВИЯХ ЦЕНТРАЛЬНОЙ РАЙОННОЙ БОЛЬНИЦЫ

The paper gives the experience with successful surgical treatment for scrotal traumatic avulsion and extensive penal scalping wound. A 28-year-old patient with an agricultural injury was taken to the central district hospital that performed three steps of Vitsin,s operation: primary surgical debridement, penile skin restoration, and scrotoplasty. This injury is extremely rare and the literature and media resources mainly report general information on the problem, the specific cases are sporadic; and this information has not been found in the Russian sources. Some reports deal with restoration of scrotal skin defect resulting from cancer treatment or Fournier ,s phlegmon, but these communications are few. Our case shows that stepwise treatment for such defects, stepwise scrotoplasty in particular, may be easily feasible at a general surgery hospital, even at a district hospital. В статье представлен опыт успешного хирургического лечения травматического отрыва мошонки и обширной скальпированной раны полового члена. Пациент 28 лет с сельскохозяйственной травмой доставлен в центральную районную больницу, где были выполнены 3 этапа операции по Б. А. Вицину: первичная хирургическая обработка раны, восстановление кожных покровов полового члена и скротопластика. Подобная травма крайне редка, и в литературе и медиаресурсах представлены главным образом общие сведения о проблеме, конкретные случаи единичны, а в отечественных источниках подобных сообщений мы не нашли вовсе. Некоторые сообщения посвящены восстановлению кожного дефекта мошонки, возникшего в результате лечения новообразований или в результате флегмоны Фурнье, но и эти сообщения немногочисленны. Наш случай показывает, что этапное лечение подобных дефектов, в частности этапная скротопластика, может быть легко выполнимо в условиях общехирургического стационара даже районной больницы