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Mechanical alloying and compactization of metallic composite powders
Husák, Roman ; Čelko, Ladislav (referee) ; Hadraba, Hynek (advisor)
Master´s thesis is focus on the proces of mechanical alloying. It is the proces of modifying a hetegeneous mixture of powder materials into a homogeneous composite powder. Experiments are focus on three types of composite materials. A magnetic soft alloy Permalloy, ODS steel based on commercially available powder steel 434 LHC and low-activation high-chrome ODS steel 14Cr-2W. On composite powders are made a series of mechanical tests and chemicel analysis. Based on this tests and analysis it was possible to confirm the milling time needed to create fully homogeneous composite powder. Next step is compaction of composite powder into compact volume and another mechanical tests ana analysis of microstructure. In these analyzes to determine whether i tis necessary to use protective atmosphere during mechanical alloying. All three type of materials succesfull prepared by mechanical alloying. It was found that for created of a fully homogeneous composite powder is necessary to perform mechanical alloying for 24 hours. When processing of corrosion resistant materials, i tis possible to perform mechanical alloying in an air atmosphere. During mechanical alloying materials which are subject to oxidation, i tis necessary to use protective atmosphere.
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Influence of parameters of electrophoretic deposition on properties of ceramics
Husák, Roman ; Čelko, Ladislav (referee) ; Hadraba, Hynek (advisor)
Electrophoretic deposition is experimentally undemanding shaping method enabling preparation of ceramic material from stable suspension of ceramic particles by means of direct electric current. The aim of the work was to describe effect of electric current magnitude on velocity and final microstructural and mechanical properties of the ceramics. The alumina and zirconia layers were prepared by electrophoretic deposition from stable suspensions of ceramic particles in the isopropanol stabilised with monochloracetic acid. It was found that the real time dependance of particle deposition differs from the theoretical predisction for given electrical conditions. By precise measurement of kinetics of the electrophoretic deposition the actual electrophoretic mobility of the particles and the actual amount of particles taking part in the deposition process were found. It was found that with increasing the electrical current the actual electrophoretic mobility was decreased and actual amount of particles taking part in the deposition process was increased. The increasing velocity of particles under higher electrical currents led to the detorioration of particle arrangement in the elctrode and thus to the increasing of the pore sizes and final densities of the deposits. These microstructural changes reflected in the lowering of the hardness of the deposited ceramics of about 300HV5 in the case of alumina.
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Advanced Composite Structural Steels for Applications in Heavy Liquid Metals
Husák, Roman ; Haušild, Petr (referee) ; Vilémová,, Monika (referee) ; Hadraba, Hynek (advisor)
Doctoral thesis was focused on preparing of new advanced ODS steels for use in heavy metal liquids enviroments. Possibility of new course for creating oxide dispersion in microstructure was verified by the course of internal oxidation of elements. By the internal oxidation method were prepared new ODS steels strengthened by complex oxides which were created by elements of IIIB and IVB group of elements. Based on analysis of damage ODS steels in LBE were designed surface protection of ODS steel by the oxide layer. The ODS steel protected by oxide layer was subjected to a corrosion test in LBE. For the experiments were chosen class of chromium steels: ferritic-martensitic steel 9Cr1WMnVTa and ferritic steels 14CrWTi and 17Cr1Mo. Steels without oxide dispersion and steel strenghtened by the dispersion based on Y-Ti-O oxides were prepared. On the steels were made series of mechanic tests which should reveal the effectivity of oxide dispersion on the strenght of steel prepared by the internal oxidation method and by the direct addition of oxide elements. It was found that significantly harder oxide material couldn't be fully disrupted through the mechanical alloying and fine oxide dispersion couldn't be created. There was verified fine oxide dispersion could be created by the internal oxidation method and by the direct adding of oxide elements. Same kind of steels strenghtened by new kind of complex oxides based on Y, Ce, Hf, La, Sc and Zr were prepared. The chemical analyses have proven that all added elements could created complex oxide by the reaction with yttrium. The computational analyses for observing of matrix influence and oxide phase influence on strenghtening of steels were performed. These computational analyses were based on microstructural analyses of ODS steels. There was found that the oxide particles could very effectively improve strenght of steels at room temperature and especialy at high temperature. Based on corrosion tests of 14Cr ODS steel in liquid Pb and LBE enviroment were designed surface protection of ODS steel. The effectiveness of protective layer was verified by the high temperature corrosion test of PM2000 in LBE. No damage of oxide layer was observed although Pb and Bi diffused through protective layer.
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Object Usage Analyser for TypeScript
Pácal, Michal ; Husák, Robert (advisor) ; Škoda, Petr (referee)
During a programming change task, developers often need to understand where a certain variable or object is referenced and how it is used in order to implement the change. For languages TypeScript and JavaScript the only available tools to find these points of interest are tools to find variable and property references and to display a call tree. These tools, however, start losing viability in larger codebases, where they can return hundreds or even thousands of results sorted only by the source file names. In this thesis, we have developed an extension for Visual Studio Code that finds these references and categorise them into groups based on usage. It can also perform similar analysis on call arguments based on the position of the argument. We evaluated our solution and showcased it in several real-world use cases.
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Code Assertions Verification Using Backward Symbolic Execution
Husák, Robert ; Kofroň, Jan (advisor) ; Parízek, Pavel (referee)
In order to prevent, detect and fix errors in software, various tools for programmers are available, while some of them are able to reason about the behaviour of the program. In the case of C# programming language, the main representatives are Microsoft FxCop, Code Contracts and Pex. Those tools can, indeed, help to build a highly reliable software. However, when a company wants to include them in the software development process, there is a significant overhead involved. Therefore, we created a "light- weight" assertion verification tool called AskTheCode that can help the user to focus on a particular problem at a time that needs to be solved. Because of its goal-driven approach, we decided to implement it using backward symbolic execution. Although it can currently handle only basic C# statements and data types, the evaluation against the existing tools shows that it has the potential to eventually provide significant added value to the user once developed further. Powered by TCPDF (www.tcpdf.org)
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Interoperability of compiled PHP framework with .NET environment and package management
Horký, Filip ; Husák, Robert (advisor) ; Kofroň, Jan (referee)
PHP language has been dominating the web development industry for a long time now. Each major PHP framework brings together a large community and a solid codebase, providing features and tools that make the PHP web application devel- opment even simpler. Joining this vast world with .NET is an aim of Peachpie, PHP compiler to .NET. This provides means to use Symfony framework in .NET, yielding advantages for both the PHP developers striving for more security and the .NET programmers lacking third-party content. Doing so with plain Peachpie compiler, however, brings problem of actual usability of the features Symfony pro- vides. Each project would require to recompile Symfony Components again and thus result in both time overhead and tedious manual configuration. This thesis shows it is possible to improve this process and enable intuitive usage of Sym- fony framework in the .NET environment. It denotes utilities for semi-automatic compilation of the Symfony Components into the NuGet packages and migration of simple Symfony applications to .NET. Furthermore, it provides tools for ad- ditional interoperability between Twig and Razor template engines, and a set of examples of its actual usage.
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Performance testing suite for Unity DOTS
Borufka, Roman ; Gemrot, Jakub (advisor) ; Husák, Robert (referee)
Game developers are searching for new ways of writing high performance code in order to adapt to trends in hardware development. Unity's relatively new DOTS system has introduced a new way, how to write code in order to fully exploit all aspects of modern processors, e.g. multithreading or SIMD instructions. The thesis focuses on creation of a generally-usable performance testing suite in order to benchmark the performance of various features of Unity DOTS system. Based on the results of the benchmarks a list of recommendations for writing high-performance solutions in Unity is compiled. The recommendations are evaluated in a real-time boids simulation.
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Advanced Composite Structural Steels for Applications in Heavy Liquid Metals
Husák, Roman ; Haušild, Petr (referee) ; Vilémová,, Monika (referee) ; Hadraba, Hynek (advisor)
Doctoral thesis was focused on preparing of new advanced ODS steels for use in heavy metal liquids enviroments. Possibility of new course for creating oxide dispersion in microstructure was verified by the course of internal oxidation of elements. By the internal oxidation method were prepared new ODS steels strengthened by complex oxides which were created by elements of IIIB and IVB group of elements. Based on analysis of damage ODS steels in LBE were designed surface protection of ODS steel by the oxide layer. The ODS steel protected by oxide layer was subjected to a corrosion test in LBE. For the experiments were chosen class of chromium steels: ferritic-martensitic steel 9Cr1WMnVTa and ferritic steels 14CrWTi and 17Cr1Mo. Steels without oxide dispersion and steel strenghtened by the dispersion based on Y-Ti-O oxides were prepared. On the steels were made series of mechanic tests which should reveal the effectivity of oxide dispersion on the strenght of steel prepared by the internal oxidation method and by the direct addition of oxide elements. It was found that significantly harder oxide material couldn't be fully disrupted through the mechanical alloying and fine oxide dispersion couldn't be created. There was verified fine oxide dispersion could be created by the internal oxidation method and by the direct adding of oxide elements. Same kind of steels strenghtened by new kind of complex oxides based on Y, Ce, Hf, La, Sc and Zr were prepared. The chemical analyses have proven that all added elements could created complex oxide by the reaction with yttrium. The computational analyses for observing of matrix influence and oxide phase influence on strenghtening of steels were performed. These computational analyses were based on microstructural analyses of ODS steels. There was found that the oxide particles could very effectively improve strenght of steels at room temperature and especialy at high temperature. Based on corrosion tests of 14Cr ODS steel in liquid Pb and LBE enviroment were designed surface protection of ODS steel. The effectiveness of protective layer was verified by the high temperature corrosion test of PM2000 in LBE. No damage of oxide layer was observed although Pb and Bi diffused through protective layer.
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Farm data management
Dolník, Marián ; Kofroň, Jan (advisor) ; Husák, Robert (referee)
Title: Farm data management Author: Marián Dolník Department: Department of Distributed and Dependable Systems Supervisor: RNDr. Jan Kofroň, Ph.D., Department of Distributed and Dependable Systems Abstract: The purpose of this bachelor is to design and implement an application which would simplify work organization on a farm by recording information about pickers, their logging data, and by further processing of these data. This software project consists of a mobile and a web applications and a synchronization unit. The purpose of the synchronization unit is to synchronize data of the local mobile database with the data from the main database. The mobile application has the purpose of storing the data. Collecting the data is executed by user interface, allowing one to define data by choosing a value of the required attributes. Among other functions, the mobile application allows the user to work with already existing data (filter data by multiple conditions, remove data, collect data in order to obtain statistics, synchronize data with the main database). The web application displays and manages worker's data. It creates the statistics about worker's efficiency and field's fertility. It defines access rights, which provides the users with access to specific parts of the web application, optionally allowing...
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