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AWS Viscometry – Principles and Applications
Wein, Ondřej
Quantitative identification of Apparent wall slip (AWS) effect, accompanying the flow of colloidal dispersions in confined geometries, requires a specific modification of common viscometric methods. Essential distinction between common and AWS viscometry is outlined – including theoretical background, calibration, data acquisition, and downstream data treatment – and demonstrated for a class of rotational viscometers.
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An Educational Application for Relational Calculus Query Evaluation
Sabol, Viliam ; Lánský, Jan (referee) ; Skopal, Tomáš (advisor)
The task of this thesis is implementation of an application for educational purposes, which will be used for evaluating queries in tuple relational calculus. It is aimed at visualization of query structure and evaluation process. The application is especially intended for understanding evaluation process of queries in tuple relational calculus on simple user defined database. The output of the application is a tree structure of query, and requested data from database. The application allows user to trace the evaluation process and watch values of variables used in query and results of operations in query tree.
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Dust-UV interaction
Nouzák, Libor ; Pavlů, Jiří (advisor) ; Žilavý, Peter (referee)
Title: Dust - UV interaction Author: Libor Nouzak Department: Department of Surface and Plasma Science Supervisor: RNDr. Jiri Pavlu, Ph.D. Supervisor's e-mail address: jiri.pavlu@mff.cuni.cz Abstract: Micrometer objects (dust grains) are an integral part of the universe. As other objects in the plasma, these dust grains charge to potencial close to the potencial of the plasmas (in this case, interplanetary plasma). In the universe, the photoelectric charging dust grain dominantes all other charging processes. In general, the resulting charge of dust grain is given by a balance of all processes, which haven't been mostly jet theoretically described. In our laboratory, we are simulating space conditions and measure resulting charge and his changes on a single separated dust grain. This work is partly focused to UV source application and to finishing its electronics, and partly on test measurements and model calculations, connected with newly built experiment (e.g., to estimate effects of backgound currents, surfaces, and the geometry of the dust trap electrodes). The work is finished by the first measurements of glass grain charge under electron bombardment with provisional detection optics. Obtained results are compared with previous measurements on the same type of dust grains. Key words: dust, dusty plasma,...
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Blood vessel segmentation and modeling in fundus images
Václavík, Jan ; Odstrčilík, Jan (referee) ; Kolář, Radim (advisor)
Studies of the vascular tree in the retina have applications not only in the medical field but also biometrics. The mathematical description of the retinal vasculature could help facilitate and improve the diagnosis of certain diseases, their automatic localization or to accelerate the identification and verification of individuals. The aim is to design and develop an algorithm that will automatically approximate major retinal vessels by parabolic, linear and kvartic functions. The main part of this thesis is therefore devoted to this issue, including vascular segmentation using Gabor filters, morphological erosion, thresholding, skeletonization and the resulting optimization of the approximation model. The quality of the produced algorithm is discussed in the summary.
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Noise control of computers-application of optimal sound isolation layers and fun rotation speed
Kunovský, Martin ; Mišun, Vojtěch (referee) ; Pellant, Karel (advisor)
This thesis deals with the distribution of noise in the computer case and radiation into the neighborhood. Influence of geometrical shape and size of the computer case on radiated noise from the computer was investigated as well as effect of placement of the fan. Reducing noise by using sound absorbing material into computer case and result of the suitable position of the computer in the working environment were also tested. Simulation of the noise diffusion and effectivity of anti-noise equipment was executed in Ansys FEM program.
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Application for Tree Stability Measurement
Šoltés, Jakub ; Kolář, Martin (referee) ; Polok, Lukáš (advisor)
This thesis is concerned with the subject of tree stability under a wind load. It defines, what the tree stability is, which techniques are used for its measurement and why it is important to determine it. It describes development process of application, that examines tree stability. Furthermore it analyses available the development tools, discusses a design and an implementation of the application written in C# language. Application has been created using .NET Framework along with graphical subsystem Windows Presentation Foundation following the design pattern Model View ViewModel. The result of this thesis is a desktop application aimed on Windows operating system. It can compute stability coefficient of the tree using information about trees‘ geometry and its environment. The value of stability coefficient is commonly used for tree safety inspection.
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Fly over Rugged Planet
Pospíšil, Petr ; Chudý, Peter (referee) ; Jošth, Radovan (advisor)
This thesis deals with a 3D visualization of the Earth´s surface in real time. A significant part is dedicated to the buffering of the large amount of data (a height map and textures of Earth) and its effective reading from hard disk directly to the memory of a graphic card. Individual levels of detail of the Earth´s surface are made by GeoMipMapping. The algorithms "horizon" and "frustum culling" are used, which cut off the hidden parts of the planet. The application of the height data is based on a custom algorithm calculating the data directly in the graphic card, in assistance with its vertex and geometry shaders.
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3D Lattice Structures for Application in Selective Laser Melting technology
Červinek, Ondřej ; Škaroupka, David (referee) ; Vrána, Radek (advisor)
Additive technologies allow manufacturing of components with very complex shapes which are difficult to manufacture with conventional technologies. Among these technologies belongs the Selective Laser Melting (SLM). Suitable applications of SLM include manufacturing of light-weight 3D structures like lattice structure or an organic geometry called gyroid. This bachelor thesis is focused on creation of models of gyroid structure and its application to parts followed by manufacturing with SLM. Series of models were made with mathematical software. Implicitly defined equation were used for better geometry coordination of created models. Options utilization and manufacturability of gyroid structures were tested within application into turbocharger impeller. At the end of this thesis was successfully manufactured the impeller including two types of gyroid structure (single-gyroid and double-gyroid)
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Propagation of inclined cracks to the interface of ceramic laminates
Novotná, Lenka ; Trunec, Martin (referee) ; Chlup, Zdeněk (advisor)
Composite materials with laminated structure provide advantages which are utilised during component design. Low density, temperature and chemical stability are the profitable properties predetermining application of ceramic laminates. The main obstacle for wide spread of ceramic materials is their inherent brittleness. Therefore, in this thesis, the crack propagation in ceramics laminates has been extensively studied. Laminated structures with various volume fractions of components (alumina and zirconia) were prepared by electrophoretic deposition. Evaluation of crack propagation through the interface and determination of basic mechanical properties was conducted on the basis of extensive literature search. Crack deflection originated in both presence of internal stresses and differences in elastic modulus during the crack interface passing was monitored. A special type of specimen geometry was employed with the aim to set arbitrary angle between crack and interface. It was experimentally found that the degree of crack deflection is dependent on entering angle and volume fraction of components. Higher crack deflection was already found in the bulk of the test piece comparing to the test piece surface. The 3D fracture surface reconstruction generated using laser confocal microscopy was used in this detailed crack propagation study. Further basic elastic and strength characteristics of laminates were determined and compared to those obtained from monolithic materials. The validity of the mix rule for elastic characteristics was confirmed by comparing of elastics modulus. The most reliable method for elastic modulus determination was marked the dynamic resonance method due to low scatter and consistency in measurement. The flexural strength of all laminates tends to be close to the flexural strength of the weakest component. Therefore the mix rule is not applicable for flexural strength estimation on the contrary of elastic characteristics. The change of component volume fraction leads only to change of flexural strength scatter. Thanks to gained knowledge about crack propagation and basic characteristic determination will be possible to design ceramic laminates more efficiently for given needs of application.
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