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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
311

Rozhledna v Brně Kohoutovicích / Watchtower in Brno Kohoutovice

Komárek, Ondřej January 2019 (has links)
The main aim of my master´s thesis was to design a load-bearing steel structure of the lookout tower situated in Brno-Kohoutovice. The height of the load-bearing structure is 35.5 m. My design comprises two different engineering solutions. Solution A is a lattice space frame whereas Solution B works with continuous columns with vertical bracing. For further development, Solution A has been chosen. The proposed structural material is the S355 steel. My thesis includes an engineering report, a statics analysis and drawing documentation.
312

Vyhlídková věž v oblasti Brdy / The Viewing Tower in Brdy

Kováčová, Kristýna January 2019 (has links)
The subjekt of this thesis is a design of a viewing tower located in the area of Brdy. The structure has been created as a 3D model, the internal forces have been calculated with the use o finite element method in a structural engineering software Scia Engineer 15.1. Based on the knowledge of theses forces the design of the structural systems has been done. The materials used on this construction are glued laminated timber and steel. The height of the tower is 25,725 m. The floor plan is a shape of a circle and fluctuating smaller with the gaining height. The main structural systém consists of 8 curved posts which are radiály situated on the circular floor plan. The tower has 3 observational platforms.
313

Restaurace s vyhlídkou / Restaurant with Point of View

Bittman, Jaroslav January 2014 (has links)
The aim of the master thesis „ Restaurant with a view“ is project for realization of a building. The building is situated in city district Brno – Veveří. New building will be placed instead of a current garage in the end of the street Rybkova. The building has two floors. The bearing system is a combination of ceramic bricks Porotherm and reinforce conrete frame. The frame consists of columns and longitudinal girders. The ceiling is a monolithic reinforce concrete slab. The roofs above both floors are flat and walkable with waterproofing layer made of modified bitumen sheets. The walkable layer is made of concrete paving with a rectification targets. The projekt also solves preparation for possible placing of wooden tower on the roof of the second floor. Wooden tower was made just as initial design.
314

Naklápěcí a zdvihový mechanismus skladovacího zásobníku / Tilt and lift mechanism of storage tray

Ostrý, Josef January 2014 (has links)
The aim of this master thesis is to design a structural arrangement of lifting and tilting mechanism storage tower SSI Logimat, including the design of the drive. The introduction included a description of selected vertical storage systems of different companies and then compared them. Another section includes the design lift and tilt mechanism, calculation and design their drives and the subsequent description of their components. At the end of the master thesis is attached the drawings of the proposed mechanisms.
315

Nosná ocelová konstrukce rozhledny / Steel Structure of Observation Tower

Virág, Patrik January 2016 (has links)
The subject of the diploma thesis is design and structural analysis of loadbearing steel structure of observation tower, which is located southeast of Černá Hora, township Blansko. The design is processed in two options. Parts of the thesis are engineering report, structural design report for both of the options and graphical documentation in specified range. The structure’s height is 25.3 m and maximal ground plan dimension is 6 x 6 m. Steel grade S355 was chosen as main material. The sub-objectives of the structural analysis are load effects calculations (permanent load, imposed load and climatic load), entering of loads to the calculation model and calculation of internal forces and deformations. An assessment of the supporting elements and selected joints is also included. There are dynamic design features considered in the calculation. All calculations were performed in accordance with valid ČSN EN standards.
316

Klimatická data pro klimatizaci / Climatic data for air conditioning

Veselský, Marek January 2016 (has links)
The aim of diploma thesis is a processing of climate data and design of chiller. Chiller is proposed to two options: air-cooled chiller and chiller with open cooling tower.
317

Ein Lasersystem für Experimente mit Quantengasen unter Schwerelosigkeit

Schiemangk, Max 29 March 2019 (has links)
Bereits Galilei untersuchte, ob verschiedene frei fallende Körper im Schwerefeld der Erde gleich stark beschleunigt werden, die sogenannte Universalität des freien Falls. Die Genauigkeit der experimentellen Überprüfungen konnte seitdem beständig gesteigert werden. Einen neuen Ansatz, die Messgenauigkeit noch weiter zu verbessern, bilden quantenmechanische Messmethoden, die auf Materiewelleninterferometrie beruhen. Die dabei genutzten Apparaturen verwenden Laserstrahlung zur Kühlung, Manipulation und Detektion der Atome. Ziel der vorliegenden Arbeit war die Entwicklung des Lasersystems für ein neues Experiment, das erstmals Zwei-Spezies-Atominterferometrie (mit Rb & K) in Mikrogravitation demonstrieren soll. Ein Lasersystem, das sowohl die funktionalen Anforderungen als auch die aus dem Einsatz auf dem Katapult des Fallturms resultierenden Anforderung (Volumen < 44 l, Masse < 35 kg und voll funktionsfähig sofort nach einem Katapultstart mit Beschleunigungen von 30 g) erfüllt, wurde funktional konzipiert und mechanisch designt. Zur Demonstration wurde der Rubidium-Teil des Lasersystems funktional sowie mechanisch qualifiziert. Inzwischen wird er routinemäßig für Experimente am Fallturm eingesetzt. Für das Lasersystem wurden kompakte und robuste schmalbandigen Lasermodule entwickelt. Diese liefern bei einer Grundfläche der optischen Bank von nur 10 mm x 50 mm Ausgangsleistungen von bis zu 3,7 W. Am Arbeitspunkt (1 W Ausgangsleistung) besitzen die Strahlquellen Linienbreiten im Bereich von 100 kHz (Lorentz) bzw. 1 MHz (-3 dB, 10 µs). Zum Nachweis der spektralen Stabilität der Lasermodule wurde ein Messverfahrens zur Charakterisierung des Frequenzrauschens freilaufender Laser entwickelt. Dieses basiert auf einer Schwebungsmessung mit anschließender Analyse der Quadraturkomponenten des Signals im Zeitbereich. Durch den Einsatz geeigneter Filter erlaubt es die Unterdrückung der für Diodenlaser typischen Frequenzdrifts. / Galileo, already, investigated whether different free falling bodies in the gravitational field of the Earth are accelerated at the same rate, the so-called universality of the free fall. The accuracy of the experimental tests has been steadily increased ever since. A new approach to further increase the measurement accuracy is provided by quantum mechanical measurements based on matter wave interferometry. The apparatuses used for this purpose employ laser radiation for cooling, manipulation, and detection of the atoms. The aim of this thesis’ work was the development of the laser system for a new experiment intended to demonstrate two-species atom interferometry (utilizing Rb & K) in microgravity for the first time. A laser system, which fulfills the functional requirements as well as the requirements resulting from the deployment on the catapult of the drop tower (volume < 44 l, mass < 35 kg, and fully functional immediately after a catapult launch with accelerations of 30 g), has been functionally conceived and mechanically designed. For demonstration, the rubidium part of the laser system was functionally and mechanically qualified. By now, it is routinely used for experiments at the drop tower. For the laser system, compact and robust spectrally narrow laser modules have been developed. These provide an output power up to 3.7 W at a footprint of the optical bench of only 10 mm × 50 mm. At the operating point (1 W output power), the radiation sources exhibit linewidths in the range of 100 kHz (Lorentzian) and 1 MHz (−3 dB, 10 μs). To validate the spectral stability of the laser modules a measuring method for the characterization of the frequency noise of free-running lasers has been developed. This method is based on a beat note measurement with subsequent analysis of the quadrature components of the signal in the time domain. By utilizing appropriate filters, it allows for the suppression of the frequency drifts that are typical for diode lasers.
318

Corrosion behaviour of ferrous and non-ferrous alloys exposed to sulphate - reducing bacteria in industrial heat exchangers

Prithiraj, Alicia January 2018 (has links)
M.Tech. (Department of Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology / Corrosion responses of some carbon steels, stainless steel and copper alloys in the presence of a culture of bacteria (referred to as SRB-Sulphate-reducing bacteria) found in industrial heat exchangers, was studied to recommend best alloys under this service condition, with techno-economic consideration. Water from cooling towers in three plants in a petrochemical processing complex were analysed for SRB presence. Two of the water samples showed positive indication of SRB presence. The mixed cultures obtained from plant one were grown in prepared media and incubated at 35 °C for 18 days. Potentiodynamic polarisation studies in anaerobic conditions were done on the selected alloys in aqueous media with and without the grown SRB. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were then used to study the corrosion morphology and corrosion products formation. The voltamograms show higher icorr for alloys under the SRB compared to the control media, indicating the SRB indeed increased the corrosion rates. The surface analysis showed pitting on steel alloy ASTM A106-B. Localised attack to the grain boundaries on a selective area, was seen on ASTM A516-70 dislodging the grains, and intergranular corrosion was seen throughout the exposed area of ASTM A179. Copper alloys showed pitting on ASTM B111 grade C71500 (70-30), and denickelification on ASTM B111 grade C70600 (90-10), and is a good alternative material for use apart from carbon steel alloys, recording a low corrosion rate of 0.05 mm/year. The EDS analysis supported the findings showing higher weight percent of iron and sulphur on surface of the alloys after exposure to the SRB media. This implies that the presence of the sulphur ion indeed increased the corrosion rate. ASTM A516-70 carbon steel was chosen as a suitable alternative material to the stainless steel in this environment. The Tafel plot recorded a corrosion rate of 1.08 mm/year for ASTM A516-70 when exposed to SRB media.
319

Gleichungsorientierte Modellierung der Wärme- und Stoffübertragungsprozesse in Verdunstungskühltürmen

Schulze, Tobias 24 July 2015 (has links)
Zur Kühlung von Prozessströmen kommen aufgrund hoher Leistungsdichten häufig Verdunstungskühltürme zum Einsatz. Um die Übertragungsfläche für Wärme und Stoff zu vergrößern, werden in diesen Kühltürmen Struktureinbauten integriert. Die Weiterentwicklung von Kühlturmeinbauten und die Untersuchung der den Kühlprozess beeinflussenden Faktoren erfolgt empirisch, was eine Vielzahl von Versuchen notwendig macht. Eine numerische Simulation des Kühlprozesses kann diese Messungen unterstützen und so helfen eine Vielzahl an Versuchen einzusparen. Des Weiteren können bei versuchsbegleitender Simulation mit einem geeigneten Modell weitere Untersuchungen durchgeführt und Erkenntnisse gewonnen werden, die bei Messungen am Versuchskühlturm verborgen bleiben. In dieser Arbeit werden zwei Ansätze der numerischen Simulation eines Verdunstungskühlturms betrachtet. Es werden eine CFD-Simulation und ein vereinfachtes Modellkonzept hinsichtlich der Anwendbarkeit auf diese Problemstellung untersucht. Schwerpunkt der vorliegenden Arbeit ist die methodische Entwicklung eines solchen vereinfachten mathematischen Modells. Dieses beruht auf der physikalisch deterministischen Beschreibung der im Kühlturm ablaufenden Prozesse der Wärme- und Stoffübertragung unter Berücksichtigung des Stoffverhaltens. Aufgrund der Nichtlinearität des Stoffverhaltens und der erforderlichen Inkrementierung des Berechnungsgebiets ist ein methodisches Vorgehen erforderlich, um die Erstellung der Modellgleichungen und deren Lösung überhaupt realisieren zu können. Hierfür wird auf allgemeine Methoden der gleichungsorientierten Simulation technischer Systeme zurückgegriffen. Das entwickelte Modellkonzept wird für die Modellierung und Simulation eines Versuchskühlturms angewandt. Mit den so ermittelten Messdaten wird das Modell kalibriert und validiert. Es zeigt sich, dass mit dem erstellten Modell quantitativ und qualitativ valide Ergebnisse erzielt werden können. / Due to the high power density, the cooling of process streams is often done bei evaporative cooling towers. To enlarge the exchange area for the heat and mass transfer, these cooling towers contain integrated structural fills. The future development of cooling tower fills and the research regarding the cooling process and its influencing parameters will be carried out empirically, resulting in a large number of required experiments. A numeric simulation of the cooling process can support theses measurements and reduce the vast number of needed experiments. Furthermore, with the use of test-related simulations and adapted models, it will be possible to gain knowledge and do research in areas which are omitted during regular measurements on cooling towers. In this study it is looked to two different approaches of numeric simulation of a evaporative cooling tower. There will be an examination of a CFD-Simulation and a simplified model concept regarding their respective applicability for this problem. This work is focussed on the systematic developement of such simplified mathematical models, based on the physical deterministic description of the occurring processes of heat and mass transfer in cooling towers considering the stock behaviour. Due to the non-linearity of the stock behaviour and the required incrementation of the calculation area, a systematic approach is needed to model equations and their respective solutions. For this purpose it is necessary to access general techniques of equation-based simulations of technological systems. The developed model concept will be applied for the modelation and simulation of an experimental cooling tower. The model will be calibrated and validated with data from this experimental tower. It shows, that the results from this model are qualitatively and quantitatevily valid.
320

Vindkraftverk av UHPC 2.2 : En undersökning av högpresterande betong med syntetfiberarmeringen STRUX / Wind power plants of UHPC 2.2 : An investigation of high-performance concrete with synthetic fibre reinforcement STRUX

Rydén, Michaéla, Nilsson, Thina January 2013 (has links)
Användandet av betong som ersättare för stål vid produktionen av vindkraftverkstorn har ökat den senaste tiden. Betongtorn är betydligt billigare än ståltorn men problem som sprickbildningar, frostsprängningar och följaktligen armeringskorrosion har uppstått bl a på grund av vibrationer från rotorn. I fundamentet i vindkraftverk kan ovan nämnda problem också uppstå och det uppfyller således inte alltid funktionskraven. Det här examensarbetet undersöker möjligheten att eliminera dessa problem genom att använda en sorts högpresterande betong kallad UHPC 2.2 med syntetfiberarmeringen, STRUX. Jämförelser mellan tidigare empiri om högpresterande betong och laborativa tester på UHPC 2.2 visar att den senare är beständigare och ger möjligheter till en större sprickfrihet. Sammanfattningsvis har den högpresterande betongen med fiberarmeringen STRUX visat sig vara en konkurrenskraftig möjlighet på marknaden. / The use of concrete has recently increased as a replacement to steel for the construction of towers for wind power plants. However there are problems such as cracking or frost scaling and finally corrosion of reinforcement, partly due to vibrations caused by the power plants' blades. In the foundation of power plants, the above problems also occur and do not always fulfill the functional requirements. This thesis investigates the possibility to eliminate these problems by using a special kind of high-performance concrete called UHPC 2.2 with synthetic fiber reinforcement, STRUX. When comparing previous empirics about regular concrete with laboratory tests on this high-performance concrete, we find that the later is more durable. In summary, the high-performance concrete with fiber reinforcement STRUX is shown to be a competitive market opportunity.

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