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Active control of flow past a cylinder
Kukrle, Daniel ; Urban, Ondřej (referee) ; Rudolf, Pavel (advisor)
The diploma thesis is considering active flow control. At first part describes boundary layer separation and Kármán vortices formation. It also explains why it is important to control the flow, and the control is divided into basic categories. Then there are described known active flow control methods. Next part defines default problem with Kármán vortices formed behind a cylinder, analyzes flow and suggests useable flow control principles. In last part of the thesis are tested chosen flow control methods. At first there are verified open-loop methods, then closed-loop methods too.
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Design of a sample holder with electrical contacts for UHV SEM/SPM
Krutil, Vojtěch ; Vlček, Ivan (referee) ; Urban, Pavel (advisor)
The presented thesis focuses on designing a sample holder for an UHV SEM/SPM microscope suitable for using in low temperature (20 K - 300 K) applications. This newly designed sample holder is equipped with ten spring-loaded contacts for electrical connection of a transport pallet to the sample holder, which will be equipped with a temperature sensor and a heating element. Two quadruples of contacts are reserved for the sample and the temperature sensor and the remaining pair for the heating element. A thorough research study of commercially available sample holders indicates that the holders for the intended use are not available on the market. In the low-temperature tests of the newly designed sample holder, the limit temperature of the 24 K was reached in a test vacuum chamber with a flow cooling system. The ambient temperature was 300 K. The contact function was successfully verified by measuring the transient electrical resistance at the fixed and the spring contact sections. Additionally, a modification of the sample holder for high temperature (300 K - 700 K) was suggested.
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Aircondition of club
Urban, Ondřej ; Rubinová, Olga (referee) ; Uher, Pavel (advisor)
This bachelor´s thesis deals with the air-conditioning of a club. Its design focuses specifically on sanitary facilities and sports hall. The project of the bachelor thesis covers ventilation units, including heat recovery from a sport hall and outline of displacement ventilation.
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Cryogenic cell for study of water ice in ESEM microscope
Krutil, Vojtěch ; Kubíček, Jaroslav (referee) ; Urban, Pavel (advisor)
The presented thesis focuses on designing a cryogenic cell for the study of water ice in an environmental scanning electron microscope (ESEM). This cell allows the study ice in the temperature range 80 K – 300 K in a nitrogen gas environment with a pressure of up to 400 Pa. The cell is cooled by a flow cooling system, where liquid or gaseous nitrogen is used as a refrigerant. The cell consists of a double-walled vessel with vacuum insulation, a flow-through heat exchanger, a sample well, and a cooled cell lid. The heat exchanger was designed to be able to dissipate the heat load at the level of 1 W. The exchanger is equipped with an electric resistance heater with an output of approximately 60 W, enabling heating of the sample at speeds of up to 100 K·min-1. The design also includes an LN2 gateway located on the door of the vacuum chamber of the microscope, to which the capillaries of the heat exchanger for the intake and outlet of refrigerant are connected. During the experimental verification of the cryogenic cell in the test vacuum chamber with a pressure of GN2 ~ 400 Pa, the limit temperature of 77.5 K on the sample well was reached.
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Business Plan for Nutrition Centre Establishment
Urban, Pavel ; Švec, Marek (referee) ; Bayerová, Vladimíra (advisor)
The diploma thesis deals with the elaboration of a business plan for the establishment of a nutrition center in Olomouc. In the first part, there are elaborated the theoretical starting points for the business plan, and then the thesis deals with analyses and a segmentation of the market. Based on this information the proposal of the business plan is elaborated.
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Reduced order model of swirling flow
Urban, Ondřej ; Pochylý, František (referee) ; Rudolf, Pavel (advisor)
This thesis deals with the formulation and application of reduced order models based on extraction of dominant structures from a system utilizing the method of proper orthogonal decomposition. Time evolution of computed modes is described by a system of ordinary differential equations, which is gained by means of Galerkin projection of these modes onto the Navier-Stokes equations. This methodology was applied on two test cases Kármán vortex street and vortex rope. In both cases, a CFD simulation of one refference point was carried out and by utilizing gained modes, the corresponding reduced order models were formulated. Their results were assessed by comparing to the refference simulation.
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The Study of the Contract Award in Selected Company
Urban, Pavel ; Ing.Miloslav Krejbych (referee) ; Jurová, Marie (advisor)
The main topic of this bachelor thesis is to make a draft of process of contract in the company to maximum satisfaction with a focus on delivery schedules, quality and costs. Specifically in the company Cimbria HMD Ltd. Litomyšl which deals with manufacturing and servicing of after-harvest machinery. The theoretical part deals with information about project management. According to identified deficiencies from analysis of the current status of the contract, I deal with on its improvement.
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Helium Cryostat for Experimental Study of Natural Turbulent Convection
Urban, Pavel ; Jícha, Miroslav (referee) ; Rotter, Miloš (referee) ; Fedor,, Ján (referee) ; Musilová, Věra (advisor)
V disertační práci je popsán heliový kryostat s experimentální válcovou konvekční celou pro studium proudění při přirozené konvekci za velmi vysokých Rayleigho čísel Ra (až do řádu 10^15) a Nusseltových čísel Nu (až do řádu 10^4). Pracovní látkou je studené 4He, které umožňuje díky výhodným fyzikálním vlastnostem dosažení velmi vysokých hodnot čísel Ra. Návrh kryostatu je založen na koncepci lázňových NMR kryostatů s nízkým odparem kryokapalin. Ve středu kryostatu je umístěna konvekční cela o průměru 300 mm a výšce 300 mm. Celu tvoří horní a spodní dno a výměnná střední část. Tyto díly jsou spojeny rozebíratelnými přírubami těsněnými indiovým drátem. Výměnná část umožňuje snadnou modifikaci geometrie cely. Hlavní přednost kryostatu spočívá v minimálním vlivu konstrukce cely a použitých materiálů na studovanou konvekci. Cela kryostatu je navržena pro pracovní tlaky do 250 kPa.
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Proposal of Communication Mix in Company
Holík, Pavel ; Urban, Petr (referee) ; Milichovský, František (advisor)
This theses deals with the communication mix for the shop and e-shop. It defines important forms and concepts of marketing mix focusing on marketing communication and contains detailed analysis of current conditions which is basis for selection of individual tools of communication mix. In progress there is concept of new communication mix which is compiled to improve adverse situation of business. New communication mix should attract new customers, improve sales and strengthen its market position.
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Materials and their application in low temperature parts of STM microscope
Voňka, Jakub ; Vlček, Ivan (referee) ; Urban,, Pavel (advisor)
Průtokvý kryostat s kapalným héliem (LHe) je vyvíjen skupinou Kryogeniky a Supravodivosti na Ústavu Přístrojové Techniky pro stávající rastrovací tunelovací mikroskop (STM) pracující za pokojové teploty na Ústavu Fyzikálního Inženýrství. Tato bakalářská práce se zabýva výběrem materiálů a určením jejich vlastností pro potenciální využití v některých částech nízkoteplotního STM mikroskopu (LT-STM), se zaměřením zejména na tepelnou vodivost v teplotním rozsahu od 4 K do 300 K. Je zde probírána problematika měděných svazků pro tepelné spojení vzorku s tepelným výměníkem. Slitina CuCrZr byla podrobně zkoumána jako vhodný materiál pro držák vzorku. Byly určeny tepelné toky málo vodivými podpěrami založenými na styku sférických ploch pro použití jako izolace mezi studeným držákem vzorku a STM stolkem.
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