Quantum Drag Forces on a Sphere Moving Through a Rarefied Gas

As an application of quantum fluid mechanics, we consider the drag force exerted on a sphere by an ultra-dilute gas. Quantum mechanical diffraction scattering theory enters in that regime wherein the mean free path of a molecule in the gas is large compared with the sphere radius. The drag force is computed in a model specified by the ``sticking fraction'' of events in which a gaseous molecule is adsorbed by the spherical surface. Classical inelastic scattering theory is shown to be inadequate for physically reasonable sticking fraction values. The quantum mechanical scattering drag force is exhibited theoretically and compared with experimental data.Comment: 5 pages no figure

Directions of Convergence of the Requirements of the Main Domestic Standard for the Design of Concrete and Reinforced Concrete Structures SP 63.13330.2012 with the Requirements of the International Standard ISO 19338

Design standards on building structures should contain, first of all, the performance and assessment requirements of structures. At the same time, design standards should provide the possibility for design and construction of concrete and reinforced concrete parts of buildings and structures that meet the requirements of the Technical regulations "On the safety of buildings and structures". Taking into account the importance of ensuring the reliability and safety of buildings and structures erected with the use of structural concrete, the technical Committee of the international organization for standardization ISO TC 71 "Concrete, reinforced concrete and prestressed concrete", certifies national standards for compliance with the requirements of the international standard ISO 19338 "Performance and Assessment Requirements for Design Standards on Structural Concrete", developed by the same Committee. The standard describes the issues that should be included in the standards for the design of concrete and reinforced concrete structures (terms and definitions, basic requirements, performance requirements,loads and impacts, design estimates, requirements for manufacturing and construction, as well as quality control). These requirements are common to all standards in the design of concrete and reinforced concrete structures. In this regard, it is relevant and important to establish the possibility of presenting the National Code of rules SP 63.13330.2012 "SNiP 52.01-2003 Plain and Reinforced Concrete Structures. General Provisions" for certification for compliance with the requirements of ISO 19338. To achieve this goal, the relevant work has been done, based on the results of which were made the proposals for the submission of SP 63.13330.2012 for certification for compliance with ISO 19338:2014. These proposals are set out in the text of the article

The Influence of Low-Frequency Seismic Phenomena Effects on the Process of Boiling up the Coolant

This paper studies the low frequency seismic phenomena on the overheating boiling process and the cavitation state of the coolant in a small volume of system. This experiment is basically the imitation of the situation in a nuclear reactor core where distilled water was used as coolant during the experiment. Temperature of the coolant was recorded during the normal state and the time of implementing external low frequency. The stretched state of the liquid due to overheating and the cavitation destruction process were investigated. © Published under licence by IOP Publishing Ltd

Neutral tritium gas reduction in the KATRIN differential pumping sections

The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to measure the effective electron anti-neutrino mass with an unprecedented sensitivity of $0.2\,\mathrm{eV}/\mathrm{c}^2$, using $\beta$-electrons from tritium decay. The electrons are guided magnetically by a system of superconducting magnets through a vacuum beamline from the windowless gaseous tritium source through differential and cryogenic pumping sections to a high resolution spectrometer and a segmented silicon pin detector. At the same time tritium gas has to be prevented from entering the spectrometer. Therefore, the pumping sections have to reduce the tritium flow by more than 14 orders of magnitude. This paper describes the measurement of the reduction factor of the differential pumping section performed with high purity tritium gas during the first measurement campaigns of the KATRIN experiment. The reduction factor results are compared with previously performed simulations, as well as the stringent requirements of the KATRIN experiment.Comment: 19 pages, 4 figures, submitted to Vacuu

Assessment of Gas-Surface Interaction Models for Computation of Rarefied Hypersonic Flow

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76727/1/AIAA-36375-113.pd

Experimental Study on Performance Enhancement of a Photovoltaic Module Incorporated with CPU Heat Pipe—A 5E Analysis

As is already known, solar photovoltaic (PV) technology is a widely accepted technology for power generation worldwide. However, it is scientifically proven that its power output decreases with an increase in the temperature of the PV module. Such an important issue is controlled by adopting a number of cooling mechanisms for the PV module. The present experimental study assesses the effect of a fanless CPU heat pipe on the performance of a PV module. The experiment was conducted in June in real weather conditions in Yekaterinburg, Russian Federation. The comparative analysis of two PV panels (i.e., cooled, and uncooled) based on the electrical energy, exergy performance, economic, embodied energy and energy payback (5E) for the two systems is presented and discussed. The key results from the study are that the average temperature reduction from the cooling process is 6.72 °C. The average power for the cooled panel is 11.39 W against 9.73 W for the uncooled PV panel; this represents an increase of 1.66 W for the cooled module. Moreover, the average improvements in the electrical efficiency, and embodied energy recorded for a cooled PV panel 2.98%, and 438.52 kWh, respectively. Furthermore, the calculations of the levelized cost of energy (LCE) for the cooled PV panel indicate that it can range from 0.277–0.964 USD/kWh, while that for the uncooled PV panel also ranges from 0.205–0.698 USD/kWh based on the number of days of operation of the plant. © 2022 by the authors.Y848041; National Natural Science Foundation of China, NSFC: 41761144079, 42150410393; Chinese Academy of Sciences, CAS: 2021PC0002, XDA20060303; Ministry of Education and Science of the Russian Federation, Minobrnauka: FEUZ-2022-0031; K. C. Wong Education Foundation: GJTD-2020-14This research was funded by the Strategic Priority Research Program of the Chinese Academy of Sciences, the Pan-Third Pole Environment Study for a Green Silk Road (Grant No. XDA20060303), the Research Fund for International Scientists of the National Natural Science Foundation of China (Grant No. 42150410393), the International Cooperation Project of the National Natural Science Foundation of China (Grant No. 41761144079), the CAS PIFI Fellowship (Grant No. 2021PC0002), the K.C. Wong Education Foundation (Grant No. GJTD-2020-14), and the Xinjiang Tianchi Hundred Talents Program (Grant No. Y848041).The research funding from the Ministry of Science and Higher Education of the Russian Federation (Ural Federal University Program of Development within the Priority-2030 Program) is gratefully acknowledged: Grant number: FEUZ-2022-0031

Monitoring of the operating parameters of the KATRIN Windowless Gaseous Tritium Source

The Karlsruhe Tritium Neutrino (KATRIN) experiment will measure the absolute mass scale of neutrinos with a sensitivity of \m_{\nu} = 200 meV/c$^2$ by high-precision spectroscopy close to the tritium beta-decay endpoint at 18.6 keV. Its Windowless Gaseous Tritium Source (WGTS) is a beta-decay source of high intensity ($10^{11}$/s) and stability, where high-purity molecular tritium at 30 K is circulated in a closed loop with a yearly throughput of 10 kg. To limit systematic effects the column density of the source has to be stabilised at the 0.1% level. This requires extensive sensor instrumentation and dedicated control and monitoring systems for parameters such as the beam tube temperature, injection pressure, gas composition and others. Here we give an overview of these systems including a dedicated Laser-Raman system as well as several beta-decay activity monitors. We also report on results of the WGTS demonstrator and other large-scale test experiments giving proof-of-principle that all parameters relevant to the systematics can be controlled and monitored on the 0.1% level or better. As a result of these works, the WGTS systematics can be controlled within stringent margins, enabling the KATRIN experiment to explore the neutrino mass scale with the design sensitivity.Comment: 32 pages, 13 figures. modification to title, typos correcte

Separation plasty in the treatment of large and giant postoperative hernias of the anterior abdominal wall

The aim of the study was to present the operative technology and the results of surgical treatment of large and giant postoperative hernias of the anterior abdominal wall.Цель работы — представить оперативную технологию и результаты хирургического лечения больших и гигантских послеоперационных грыж передней брюшной стенк

Опыт хирургического лечения больных туберкулезом с поражением костей и суставов различной этиологии

Introduction. A decrease in the number of patients with tuberculosis of the bone system coincides with an increase in the number of indications and methods for operational treatment. The continuing development in skeletal tuberculosis surgery techniques determines the search for a material capable of replacing autologous bone. Therefore, the main purpose of this paper is to enhance the results of treatment of spinal caries to speed up treatment of tuberculous osteomyelitis by applying collagen material and to solve the issues of orthopedic alignment for TB patients.Materials and methods. Surgical treatment was carried out on 32 patients in 2016–2018. The patients were divided into several groups: 18 underwent transpedicular fixation of the spine, 2 had concomitant HIV-infection, 2 underwent necrectomy of vertebral bodies with anterior spondylodesis lift system, 1 underwent necrectomy of vertebral bodies with bone autoplasty and with plate fixation, 2 had cervical spine fixation, while 2 patients with pulmonary tuberculosis in the humerus traumatic fracture received intramedullary surgery.Results. 31 patients reported a positive dynamic following surgery, while a fatal outcome not connected with the surgery was experienced in one case. Complications included allergic reaction in one case, while three patients developed postoperative wound seroma (both patients having HIV infection). One patient reported pain in the lower extremities following TPF. 3 patients with osteitis underwent necrectomy and filling of cavities with collagen material. Wounds were healed by secondary healing, while no rejection of collagen material took place.Conclusions. Introduction of collagen material in osteitis treatment can speed up fistula healing. The research work demonstrated the possibility of providing trauma care to patients under the conditions of an antitubercular centre.Введение. На сегодняшний день имеются тенденции к уменьшению количества пациентов с туберкулезом костной системы и расширению показаний и способов их оперативного лечения. Развитие хирургии туберкулеза костей определяет «поиски нового материала, способного заменить аутокость». В этой связи основная цель данной работы: улучшить результаты лечения туберкулезного спондилита, ускорить излечение туберкулезных остеомиелитов применением коллагенового материала и решить проблемы ортопедического лечения больных туберкулезом.Материалы и методы. В 2016–2018 гг. хирургическое лечение проведено у 32 пациентов. Пациенты представляли несколько групп: 18 пациентам выполнена транспедикулярная фиксация позвоночника, у двоих сопутствующей патологией была ВИЧ-инфекция, 2 выполнена некрэктомия тел позвонков с передним спондилодезом лифт-системой, 1 пациенту — некрэктомия тел позвонков с аутопластикой костью и фиксацией пластиной, 2 пациентам — фиксация накостной пластиной шейного отдела позвоночника, 2 пациентам с туберкулезом легких при травматическом переломе плечевой кости установлена интрамедуллярная система.Результаты. После операции 31 пациент отмечал положительную динамику, летальный исход был в одном случае (не связан с операцией). Из осложнений наблюдались аллергическая реакция в одном случае, у трех пациентов — серома послеоперационной раны (у обоих пациентов с ВИЧ-инфекцией). Одна пациентка после ТПФ отметила появление болевого синдрома в нижних конечностях. 3 больным с оститами сделана некрэктомия, пломбировка полостей коллагеновым материалом. Заживление ран произошло через вторичное заживление, отторжения коллагенового материала не произошло.Заключение. Внедрение коллагенового материала в лечение оститов позволяет ускорить заживление свищей. Обоснована возможность оказания травматологической помощи больным в условиях противотуберкулезного учреждения