Электродвигатель малошумного вентилятора

В данная выпускная квалификационная работа посвящена разработке 3D моделей компонентов электродвигателя ДС-200 малошумного вентилятора специального назначения. Модели были выполнены с помощью программы T-flex. В работе представлены чертежи и рисунку основных деталей, из которых состоит данный двигатель. Почти каждый элемент имеет сложную геометрическую форму, поэтому 3D моделирование электродвигателя – трудоемкая и нетривиальная задача, требующая понимания как формы каждой детали, так и инструментария CAD-системы для создания 3D модели. Электродвигатель ДС-200 состоит из 5 сборочных единиц, около 700 деталей и 200 стандартных изделий. 3D модель каждой детали была выполнена по чертежам, которые предоставил НПЦ "Полюс". В конечном итоге была разработана и собрана 3D модель электродвигателя.In this final qualification work is devoted to the development of 3D models of the components of the electric motor DS-200 low-noise fan for special purposes. Models were performed using the program T-flex. The paper presents drawings and drawing the main parts that comprise the engine. Almost every element has a complex geometric shape, therefore the 3D modeling of the motor is time-consuming and non-trivial task that requires understanding of how shape of each part and the tools of a CAD system to create 3D models. Electric motor DC-200 consists of 5 modular units, about 700 parts and 200 standard products. 3D model of each part was made according to the drawings provided by NPTS "Polyus". In the end, was designed and assembled 3D model of the motor

Источник ионизирующего излучения

Для целей дефектоскопии разработан и исследован источник ионизированного излучения, работающий на основе электрического вакуумного разряда. Проведены исследования по влиянию остаточного газа на протекание токов в разрядной камере в диапазоне Ю-1-Ю-6 тор. Рабочий режим, при котором развивается нормальный вакуумный разряд, находится ниже Ю-3 тор. Максимальный ток пучка ускоренных электронов при напряжении на катоде 200 кв составил 240 а в импульсе. Через тонкое полиэтиленовое окно электронный ток выводился в воздух, при этом на выходе окна зарегистрирован ток в 20 а при напряжении 150 кв. При замене вольфрамовой сетки анода на танталовую фольгу трубка генерирует рентгеновское излучение. Исследована работа двух катодов различной конфигурации (острие, цилиндр). Были проведены эксперименты по просвечиванию различных материалов с целью выявления дефектов и определения радиографической чувствительности

Detecting massive gravitons using pulsar timing arrays

Massive gravitons are features of some alternatives to general relativity. This has motivated experiments and observations that, so far, have been consistent with the zero mass graviton of general relativity, but further tests will be valuable. A basis for new tests may be the high sensitivity gravitational wave experiments that are now being performed, and the higher sensitivity experiments that are being planned. In these experiments it should be feasible to detect low levels of dispersion due to nonzero graviton mass. One of the most promising techniques for such a detection may be the pulsar timing program that is sensitive to nano-Hertz gravitational waves. Here we present some details of such a detection scheme. The pulsar timing response to a gravitational wave background with the massive graviton is calculated, and the algorithm to detect the massive graviton is presented. We conclude that, with 90% probability, massles gravitons can be distinguished from gravitons heavier than $3\times 10^{-22}$ eV (Compton wave length $\lambda_{\rm g}=4.1 \times 10^{12}$ km), if biweekly observation of 60 pulsars are performed for 5 years with pulsar RMS timing accuracy of 100 ns. If 60 pulsars are observed for 10 years with the same accuracy, the detectable graviton mass is reduced to $5\times 10^{-23}$ eV ($\lambda_{\rm g}=2.5 \times 10^{13}$ km); for 5-year observations of 100 or 300 pulsars, the sensitivity is respectively $2.5\times 10^{-22}$ ($\lambda_{\rm g}=5.0\times 10^{12}$ km) and $10^{-22}$ eV ($\lambda_{\rm g}=1.2\times 10^{13}$ km). Finally, a 10-year observation of 300 pulsars with 100 ns timing accuracy would probe graviton masses down to $3\times 10^{-23}$ eV ($\lambda_{\rm g}=4.1\times 10^{13}$ km).Comment: 13 pages, 5 figures, Accepted by Ap

protection by adrenomedullin

Ventilator-induced lung injury (VILI) contributes to morbidity and mortality in acute respiratory distress syndrome (ARDS). Particularly pre-injured lungs are susceptible to VILI despite protective ventilation. In a previous study, the endogenous peptide adrenomedullin (AM) protected murine lungs from VILI. We hypothesized that mechanical ventilation (MV) contributes to lung injury and sepsis in pneumonia, and that AM may reduce lung injury and multiple organ failure in ventilated mice with pneumococcal pneumonia. We analyzed in mice the impact of MV in established pneumonia on lung injury, inflammation, bacterial burden, hemodynamics and extrapulmonary organ injury, and assessed the therapeutic potential of AM by starting treatment at intubation. In pneumococcal pneumonia, MV increased lung permeability, and worsened lung mechanics and oxygenation failure. MV dramatically increased lung and blood cytokines but not lung leukocyte counts in pneumonia. MV induced systemic leukocytopenia and liver, gut and kidney injury in mice with pneumonia. Lung and blood bacterial burden was not affected by MV pneumonia and MV increased lung AM expression, whereas receptor activity modifying protein (RAMP) 1-3 expression was increased in pneumonia and reduced by MV. Infusion of AM protected against MV-induced lung injury (66% reduction of pulmonary permeability p<0.01; prevention of pulmonary restriction) and against VILI- induced liver and gut injury in pneumonia (91% reduction of AST levels p<0.05, 96% reduction of alanine aminotransaminase (ALT) levels p<0.05, abrogation of histopathological changes and parenchymal apoptosis in liver and gut). MV paved the way for the progression of pneumonia towards ARDS and sepsis by aggravating lung injury and systemic hyperinflammation leading to liver, kidney and gut injury. AM may be a promising therapeutic option to protect against development of lung injury, sepsis and extrapulmonary organ injury in mechanically ventilated individuals with severe pneumonia

DAfStb-Richtlinie „Betonbauteile mit Nichtmetallischer Bewehrung“: Von Forschung und Pilotprojekten zum Regelwerk

Der Einsatz von Betonbauteilen mit nichtmetallischer Bewehrung ist aktuell auf Pilotbauwerke beschränkt. Die Aufnahme der nichtmetallischen Bewehrung in den Annex R der Neufassung des Eurocode 2 zeigt aber deren steigende Bedeutung. Die für das Jahr 2022 geplante Veröffentlichung des Gelbdruckes der DAfStb-Richtlinie „Betonbauteile mit nichtmetallischer Bewehrung“ stellt einen wesentlichen Meilenstein dar, um die baupraktische Umsetzung für den Neubau zu erleichtern. Aus Forschungsprojekten ist über Pilotanwendungen mit vorhabenbezogenen Genehmigungen ein Regelwerk entstanden, das der Tragwerksplanung Vorgaben zur Bemessung und konstruktiven Durchbildung und den Herstellern Angaben zu den für die Anwendung der Richtlinie erforderlichen Kennwerten der Bewehrungen sowie Hinweise für die Bauausführung bereitstellt

Weitspannende Sandwichelemente mit vorgespannten Deckschichten aus Carbonbeton

Sandwichelemente mit Betondeckschichten besitzen gute bauphysikalische Eigenschaften, einen hohen Vorfertigungsgrad, geringe Montagezeiten und eine gute architektonische Gestaltbarkeit. Werden die Deckschichten mit einer Betonstahlbewehrung ausgeführt, ergibt sich ihre Dicke aufgrund der in EC 2 [1] geforderten Mindestbetondeckung zum Korrosionsschutz der Bewehrung zu etwa 80 mm [2]. Weiterhin wird bei der Bemessung von Stahlbetonsandwichelementen die Verbundtragwirkungen zwischen den einzelnen Schichten nicht angesetzt, sodass das volle Potenzial der Sandwichbauweise bei Stahlbetonsandwichelementen nicht ausgeschöpft wird. Das Forschungsvorhaben beschäftigte sich daher, aufbauend auf den Ergebnissen aus den Projekten HE 2637/16-1 und HE 2637/16-2 [3], s. S.356 ff ., mit der praxisnahen Umsetzung von weitspannenden Sandwichelementen mit dünnen Deckschichten unter Ausnutzung der Sandwichtragwirkung. Ein analytisches Berechnungsmodell, das im Zuge des Vorhabens entwickelt wurde, berücksichtigt die Verbundtragwirkung zwischen den einzelnen Schichten und kann das Trag- und Verformungsverhalten zutreffend abbilden.Sandwich elements with concrete facings have excellent physical properties, a high level of prefabrication, short assembly times and various architectural design options. The facings are usually produced with steel reinforcement, which leads to a thickness of about 80 mm due to the minimum concrete cover required in EC 2 [1] for corrosion protection of the reinforcement [2]. Furthermore, the bond between the single layers are not taken into account in the design of sandwich elements, so that the full potential of sandwich constructions with reinforced concrete facings is not completely exhausted. Based on the projects HE 2637/16-1 and HE 2637/16-2 [3], see page 356 et seq., the focus of the transfer project was set on wide-span sandwich elements with thin facings made of carbon reinforced concrete and their practical production. An analytical model, which was developed during the project term, takes into account the bond between the single layers and can accurately represent the load-bearing and deformation behaviour of the novel sandwich elements

Textilbeton: Tragverhalten – Bemessung – Sicherheit

Für die Anwendung des Verbundwerkstoffes „Textilbewehrter Beton“ sind die numerischen und experimentellen Grundlagenerkenntnisse zum Tragverhalten von Bauteilen in für die Baupraxis geeignete Nachweismodelle und Konstruktionsregeln zu überführen. Die aus dem Stahlbetonbau bekannten Ansätze müssen wegen der abweichenden Material- und Verbundeigenschaften für textilbewehrte Betonbauteile angepasst werden. Im Beitrag werden die grundlegenden Tragmechanismen textilbewehrter Elemente unter Zug-, Biege- und Querkraftbeanspruchung sowie punktförmiger Zugbeanspruchung beschrieben und die aus den Untersuchungsergebnissen abgeleiteten Nachweismodelle vorgestellt. Darauf aufbauend werden Sicherheitsbeiwerte für die textile Bewehrung ermittelt und die Berechnungsmodelle in ein Sicherheitskonzept eingebunden. Als einheitlicher Teilsicherheitsbeiwert für Textilbeton wird γtex = 1,5 vorgeschlagen.For the application of the composite material Textile Reinforced Concrete (TRC) the numerical and experimental knowledge of the load bearing behaviour of construction elements has to be transferred into design models and construction rules applicable for the practice. Due to differences in the material and bond properties the design approach known for steel reinforced concrete has to be adjusted for textile reinforced concrete construction parts. In this paper the basic load-bearing mechanisms of textile reinforced concrete under tension, bending and shear loading as well as under concentrated tensile loading are described and empirically derived design models are presented. Based on the experimental results safety factors for the textile reinforcements are determined and the design models are integrated into an overall safety concept. A partial safety factor for textile reinforced concrete of γtex = 1,5 is recommended

Tragverhalten von Textilbeton unter Biege- und Querkraftbeanspruchung

Textilbewehrter Beton ist ein Verbundwerkstoff aus einer Feinbetonmatrix und einer kraftgerichteten textilen Bewehrung aus ARGlasfaser- oder Carbongelegen. Die heterogene Materialstruktur der textilen Bewehrung im Verbundbaustoff Textilbeton führt zu einem komplexen Tragverhalten mit einer Vielzahl sich zum Teil gegenseitig in ihrer Wirkung beeinflussender Effekte. Aufgrund der abweichenden Material- und Verbundeigenschaften können für die Bemessung von textilbewehrten Betonbauteilen die aus dem Stahlbetonbau bekannten Modelle nicht pauschal übertragen werden. In diesem Beitrag werden die wesentlichen Erkenntnisse experimenteller Untersuchungen von textilbewehrten Elementen unter Biege- und Querkraftbeanspruchung dargestellt, die Mechanismen des Tragverhaltens beschrieben und empirisch abgeleitete Berechnungsmodelle vorgestellt

The Seventh Data Release of the Sloan Digital Sky Survey

This paper describes the Seventh Data Release of the Sloan Digital Sky Survey (SDSS), marking the completion of the original goals of the SDSS and the end of the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most of the roughly 2000 deg^2 increment over the previous data release lying in regions of low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. The survey also includes repeat photometry over 250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A coaddition of these data goes roughly two magnitudes fainter than the main survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2 in the Northern Galactic Cap, closing the gap that was present in previous data releases. There are over 1.6 million spectra in total, including 930,000 galaxies, 120,000 quasars, and 460,000 stars. The data release includes improved stellar photometry at low Galactic latitude. The astrometry has all been recalibrated with the second version of the USNO CCD Astrograph Catalog (UCAC-2), reducing the rms statistical errors at the bright end to 45 milli-arcseconds per coordinate. A systematic error in bright galaxy photometr is less severe than previously reported for the majority of galaxies. Finally, we describe a series of improvements to the spectroscopic reductions, including better flat-fielding and improved wavelength calibration at the blue end, better processing of objects with extremely strong narrow emission lines, and an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor correction

Модернизация конструкции малогабаритного 3D-принтера

В работе предложен вариант модернизации конструкции малогабаритного 3D-принтера, на основе кинематики "Ultimaker Original", а именно: предложена новая конструкция модуля перемещения и радиатора охлаждения. Исследованы технологические возможности модернизированного 3D-принтера и установлено, что он позволяет изготавливать заготовки и детали с габаритными размерами до 180х180х200 мм и точностью размеров, соответствующей IT12…14. В разделе "Финансовый менеджмент, ресурсоэффективность и ресурсосбережение" произведен SWAT-анализ, составлен график Ганта, рассчитаны затраты на реализацию проекта. В разделе "Социальная ответственность" рассмотрены вопросы экологичности и безопасности.The paper proposes a variant of modernizing the design of a small-sized 3D printer, based on the Ultimaker Original kinematics, namely: a new design of the movement module and a cooling radiator. The technological capabilities of the modernized 3D printer were investigated, and it was found that it allows the production of blanks and parts with overall dimensions up to 180x180x200 mm and dimensional accuracy corresponding to IT12 ... 14. In the section "Financial management, resource efficiency and resource conservation" produced SWAT-analysis compiled Gantt chart, calculated the cost of the project. In the section "Social responsibility" the issues of environmental friendliness and safety are considered