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Modelling, parameter estimation, optimisation and control of transport and reaction processes in bioreactors.
ŠTUMBAUER, Václav
With the significant potential of microalgae as a major biofuel source of the future, a considerable scientific attention is attracted towards the field of biotechnology and bioprocess engineering. Nevertheless the current photobioreactor (PBR) design methods are still too empirical. With this work I would like to promote the idea of designing a production system, such as a PBR, completely \emph{in silico}, thus allowing for the in silico optimization and optimal control determination. The thesis deals with the PBR modeling and simulation. It addresses two crucial issues in the current state-of-the-art PBR modeling. The first issue relevant to the deficiency of the currently available models - the incorrect or insufficient treatment of either the transport process modeling, the reaction modeling or the coupling between these two models. A correct treatment of both the transport and the reaction phenomena is proposed in the thesis - in the form of a unified modeling framework consisting of three interconnected parts - (i) the state system, (ii) the fluid-dynamic model and (iii) optimal control determination. The proposed model structure allows prediction of the PBR performance with respect to the modelled PBR size, geometry, operating conditions or a particular microalgae strain. The proposed unified modeling approach is applied to the case of the Couette-Taylor photobioreactor (CTBR) where it is used for the optimal control solution. The PBR represents a complex multiscale problem and especially in the case of the production scale systems, the associated computational costs are paramount. This is the second crucial issue addressed in the thesis. With respect to the computational complexity, the fluid dynamics simulation is the most costly part of the PBR simulation. To model the fluid flow with the classical CFD (Computational Fluid Dynamics) methods inside a production scale PBR leads to an enormous grid size. This usually requires a parallel implementation of the solver but in the parallelization of the classical methods lies another relevant issue - that of the amount of data the individual nodes must interchange with each other. The thesis addresses the performance relevant issues by proposing and evaluation alternative approaches to the fluid flow simulation. These approaches are more suitable to the parallel implementation than the classical methods because of their rather local character in comparison to the classical methods - namely the Lattice Boltzmann Method (LBM) for fluid flow, which is the primary focus of the thesis in this regard and alternatively also the discrete random walk based method (DRW). As the outcome of the thesis I have developed and validated a new Lagrangian general modeling approach to the transport and reaction processes in PBR - a framework based on the Lattice Boltzmann method (LBM) and the model of the Photosynthetic Factory (PSF) that models correctly the transport and reaction processes and their coupling. Further I have implemented a software prototype based on the proposed modeling approach and validated this prototype on the case of the Coutte-Taylor PBR. I have also demonstrated that the modeling approach has a significant potential from the computational costs point of view by implementing and validating the software prototype on the parallel architecture of CUDA (Compute Unified Device Architecture). The current parallel implementation is approximately 20 times faster than the unparallized one and decreases thus significantly the iteration cycle of the PBR design process.
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Design of small hydropower plant for specific location.
Paštěka, František ; Rudolf, Pavel (referee) ; Štigler, Jaroslav (advisor)
This master's thesis is specialised in designing of small hydropower plant for specific location. In work should be designed suitable turbine for parameters found on the site, then created a basic project documentation of small hydropower plant with all devices and used principles, so that the plant would be capable of operation. In the next part of thesis should be extented the calculation of flow in the turbine delivery and assessed effect of geometry of turbine delivery on the flow.
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Hard machining with defined geometry edge tools
Bukáček, Zdeněk ; Sedlák, Josef (referee) ; Prokop, Jaroslav (advisor)
This master’s thesis is concerned with subject matter hard machining with defined geometry edge tools. Aim master’s thesis is analysis and parameters evaluation machined surface at hard machining. This master’s thesis contain a characteristic of hard materials, used technology for cutting operation, but also tools and cutting conditions suitable for hard machining. In the conclusion are parameters evaluation machined surface the workpiece.
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Optimum design selection of a cryogenic tank
Létal, Tomáš ; Gottvald, Jakub (referee) ; Nekvasil, Richard (advisor)
The purpose of this work is to find optimal design for mounting cryogenic tank into ISO container frame. Solution is based on stress analyses of several designs and theirs interpretation. According to standards, set of tests, which all cryogenic containers have to pass before being put into operation, is created. Designs are tested by final element method using software ANSYS. At first, results of the stress analyses provide base for improvements targeted to better meeting with needs of the standards. In final stage, the results participate in optimum design selection.
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Strain-stress analysis of pathological hip joint
Stodola, Martin ; Florian, Zdeněk (referee) ; Návrat, Tomáš (advisor)
This work deals with stress-strain analysis pathological hip joint. In its introduction a research study from accessible literature sources is carried out. It covers contemporary state of scientific studies, anatomy of single components hip joint, their material properties, ways and magnitudes of loadings and most often FE model used. With use of all these informations, computational system ANSYS and gained CT scans, a model of geometry of pelvis and femur is created. Subsequently, the complete computational model o pathological hip point is compiled. On this model computational solution is executed stress-strain and sensitivity analysis. Subsequently, surgery operation is simulated on this model and it is executed stress-strain analysis. These analyses are compared with analysis of physiological hip joint.
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Cemented carbide tool materials
Bil, Miroslav ; Humár, Anton (referee) ; Kalivoda, Milan (advisor)
Main goal of this bachelor thesis is the introduction with characteristics of tool materials and assessing their fitness for use in machining operations. The thesis also deals with the parting-off tools, blade geometry issues, a general overview of the tool material group of cemented karbide cutting tools and their properties. There is a mention of overview of companies and world development.
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Stripping of original coats of cutting tools before new coating
Něnička, Jakub ; Novák, Zdeněk (referee) ; Humár, Anton (advisor)
Characteristics of coating methods PVD, CVD, PACVD, MTCVD. The parting of the PVD methods. Advance operations before coating of round tools and hobs. Chemical stripping of HSS. Electrochemical stripping of AlCrN coats. Differently experimental methods of stripping of the cemented carbides. Finding of the most favour stripping method with help of the electron microscope. The history of the coating. Types of coats, their usage, properies and testing. Coating machine, description and characteristics data. Preparation of tools on the coating. Behaviour of the coating process. Signification of the geometry, cutting material and coating in relation to tool life. Test evaluation of the hobs.
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Production of supporting holder by solid forming
Kopecký, Martin ; Podaný, Kamil (referee) ; Kopřiva, Miloslav (advisor)
This diploma thesis has been elaborated within the Master's study of department 2307 that submits a production proposal of supporting holder by solid forming. The used material of the forging is steel ČSN 12050 with yearly production of 100 000 pieces. The forging has been performed using drop forging method by two operations at the crank forging press LZK 1000, with induction heating of semi-finished product and flash trimming at the trimming press LKOA 200. For this method have been performed required technological calculations, geometric design of the die and assigning production machines needed for this technology. A part of this study is an economical evaluation where have been stated production expenses and prices of the forging of assigned component.
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Image processing of CT and MRI data for biomechanical applications
Nagy, Ivan
In the case of image processing to obtain the geometry of tissues means an image segmentation. A segmentation is a process subdividing an image into its constituent parts or objects. There are some basic ways to achieve this. For detecting intensity discontinuities (borders) edge detectors are used. They can be implemented as approximate mathematical gradient operators or derivative operators. This paper prasents comparison of edge detectors on a set of CT images of human body.
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