National Repository of Grey Literature 1,940 records found  beginprevious1922 - 1931next  jump to record: Search took 0.09 seconds. 

Tlakem poháněná mikrofluidika
Tesař, Václav
Microfluidics is a new field of fluid flow generation and control at small scales, making possible fundamental changes in some engineering and biomedical fields. Particular advantages bring devices operating without moving parts – but at the usually small Reynolds number it is difficult to use jet inertia,upon which no-moving-part fluidics is based. The paper presents, on an example, a solution: flow assisted - or downright driven - by applied pressure difference.

Accidental Installations
Uljarevic, Branka ; Skalík, Tomáš (referee) ; Ambrůz, Jan (advisor)
The endless possibilies of glass are inspiring. It has the ability to not only reflect, but its unbelievably sharp and crisp potential to shape and define a room from bare abandonment to pure visionare of endless value.Some of the topics and themes I seek to define and discuss through my work are as follows: What is the ability of a mere (2m x 3x) piece of glass to transform and affect the human experience? How much does its shape and placement interact with elements of the technical space, with the footprints that shape its surroundings? How does the tampering with said glass (for example, discoloration and lighting) react and influence an otherwise abandoned and unnoticed factory setting? What areits technical abilities and limitations? My conclusive research and experimentation through my thesis has led me to show the durability and strength of an otherwise breakable medium. My work has exposed the pressures and challenges that affect the dimensions in which glass can be found, from three specific angles. Not only has the quality of glass been put to the test, but its lifespan as a whole in a variety of difficult circumstances. Through this exporative installation of glass and its role of interaction, my primary goal is to analyze and expose the quality of the material. The otherwise ephemeral nature of glass as a barrier or as a second-rate mirror can be seemingly eternalized for an effective moment in time. This exploration will transform my process into afinal product, thus organizing the accidental chaos of its very specific potential.

Possibilities of improoving blades profiles efficiency
Uruba, Václav
The physical mechanism of force origin exerting on blades in flow is to be explained. The\nway for modification of blades flow parameters will be indicated, special attention will be\npaid to drag and lift forces as well as to pressure loses.

Design of testing rig for static and cyclic stress by pressure
Gerák, Jakub ; Polášek, Přemysl (referee) ; Škopán, Miroslav (advisor)
This diploma thesis describes the design of equipment for static and cyclic loading of coolers by pressure. The aim is to first identify the necessary parameters from the tested coolers. Then, based on the obtained data, design the hydraulic circuit, including the parameters of individual components and motors, followed by the design the control logic, which is required for designing the control system.

Model of cleaning station for food processing technology controlled by a control system na PROFIBUS network.
Vyskočil, Jaromír ; Sobotka, Milan (referee) ; Pásek, Jan (advisor)
This bachelor’s thesis deals with design, realization and laboratory commissioning of the model of keg / tank cleaning station (CIP) in foodstuff industry. The model uses two cleaning liquids – water and lye. There are several different types of valves used in the CIP model. They serves for inlet and outlet of lye or water and for separation of the both liquids branches. The control system offers monitoring of pressure, volume flow, level of the lye, etc. The measuring devises mostly communicate with PLC via industrial net PROFIBUS-DP and PA. The same net PROFIBUS-DP also provides communication between PLC and distributed control system Festo (valve island). Configuration and set up of the Festo valve island is described in the thesis as well. Further the work presents processing of the analogue values from different transmitters and their representation in a operator panel. Operator panel (OP) serves for control and visualization of the cleaning station. The OP configuration, the screens structure and the full functionality in the CIP station is explained. The individual screen description is incorporated as well. There are three modes of control – manual, semiautomatic and automatic. Automatic control is based on the recipe concept and the cleaning philosophy is split into several phases. The PLC control is presented in the form of flow diagrams algorithms and the program code in STEP7 is enclosed in attachment on CD ROM.

The Influence of the Carrier Gas on the Homogeneous Nucleation Kinetics. Experiments in Supersaturated Vapors of 1-Propanol in Helium
Ždímal, Vladimír ; Brus, David
The influence of a carrier gas on homogeneous nucleation kinetics was studied in this work. The experiments were carried out in supersaturated vapors on n-propanol, helium was used as a carrier gas. Local rates of nucleation as a function of total pressure were determined at constant temperature and supersaturation. A systematic decrease of homogeneous nucleation rate was observed with increasing total pressure.

Shape Measurement of Loaded Tyre
Hlavatý, Jiří ; Vančura, Jan (referee) ; Blaťák, Ondřej (advisor)
This thesis is focused on measuring the shape of loaded tire and finding dependencies between inner tire pressure, load and the influence of these parameters on the resulting shape of the tire. Data for these dependencies were obtained by using a constructed measuring stand and 3D optical technology. Found dependencies describe the change in shape of the tire in specific mathematical functions, and served the creation of a parametric model of the tire. The main finding of this thesis is that the tire is actually behaves according to dependencies described by varying degrees of polynomial function.

Increasing lifetime of outlet on high-pressure adapter
Doležal, Jiří ; Fiala, Zdeněk (referee) ; Zemčík, Oskar (advisor)
The goal this work is solve the case of customer complaint. The solved part is loaded by high pressure and extend the service life will be considered a number of possible solu-tions. Among them will be selected to best in terms of technical, economic, and rate of delivery.

Magnetic transformation of metastable fcc Fe/Cu(100) films by focused ion beam
Gloss, Jonáš ; Cháb, Vladimír (referee) ; Urbánek, Michal (advisor)
Metastable paramagnetic face-centered cubic (fcc) Fe thin films deposited on a Cu(100) single-crystal are good candidates for focused ion-beam magnetic patterning, due to their structural and magnetic phase transformation to ferromagnetic body-centered cubic (bcc) Fe upon ion-beam irradiation. However, pure fcc Fe films undergo spontaneous transformation when their thickness exceeds 10 ML. This limit can be extended to approximately 22 ML by deposition of Fe at increased CO background pressures. We show that much thicker films can be grown by alloying with Ni, that stabilizes the fcc phase. The amount of Ni necessary to stabilize non-magnetic, metastable fcc Fe films in dependence on the residual background pressure during the deposition is determined and a phase diagram revealing the metastable region is presented. It is also shown that the stabilizing effect of CO can be removed by artificial O saturation of the surface and thus the Ni-stabilized films can be grown also in systems with lower vacuum. Finally, we present fabrication of micro- and nanostructures in 44 ML thick films of Fe alloyed with Ni on Cu(100) by focused ion beam.

Measurements of the stress in the turbine spiral casing using the strain gauges
Dokoupil, Pavel ; Pochylý, František (referee) ; Habán, Vladimír (advisor)
The Master‘s thesis is focused on measuring of the stress in the spiral case of water turbine using the strain gauges measurement. It contains the theoretical and the practical part. The theoretical part includes a description of theoretical background (basic mechanics, measurement and evaluation, strain gauges, pressure measurement, uncertainty of measurement). One of the chapters describes Water Power Plant Lipno nad Vltavou (history of power plant, issues and the history of measurement). The practical part contains a theoretical calculation of measurement uncertainty and measuring of stress on spiral case Francis turbine at Water Power Plant Lipno I (Unit TG2). Measurement was made before and after overhaul. There are described technical data of spiral cases, description of measurement, results of measuring of strain and stress including comparison with the pressure in spiral case and calculation of uncertainties of measurement.