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A single-speed gearbox made by 3D printing
Hykolli, Denis ; Jaroš, Aleš (referee) ; Fiala, Zdeněk (advisor)
The aim of these theses was the creation of a single-stage gearbox by additive technology FDM / FFF. By chosen values was made dimension calculation for gears. The 3D model of the gearbox was designed in 3D software Autodesk Inventor. Single parts were produced on an FDM 3D printer by Prusa Research. Manufacturing programs for parts were prepared in PrusaSlicer. These programs were used for producing individuals parts on 3D Printer. Transparent material and printing parameters for the top of the gearbox were chosen by visual test and test of light intensity. The total cost of model production is calculated in the work. The result of these is a completely working model of a single-stage gearbox with a transparent top of the gearbox.
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Comparison of tensile properties of polymeric samples produced by extrusion based 3D printing
Krajcar, Ivo ; Vespalec, Arnošt (referee) ; Škaroupka, David (advisor)
The subject of this work is a summary of the contemporary knowledge about 3D printing and mechanical properties of a prototype manufactured this way. Main goal is to compare the frequently used FDM method with the innovative APF method of 3D printing from the Arburg company. ASA and CPE materials were chosen for researching this method. On these materials, tensile strength was measured. Aditionally, for comparison between the two methods, referential samples manufactured by injection moulding were made. A percentual difference in strength of each sample was compared against these. 60 samples in total were made for this comparison. After evaluation of the results, it was found that in the tensile strength the samples made by the APF method are approximately 30 % less strong than the referential sample. The samples made by the FDM method are approximately of the same strength as the referential sample.
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Testing of selected material properties for 3D printing
Čáslavský, František ; Mačák, Martin (referee) ; Vyroubal, Petr (advisor)
This thesis deals with 3D printing, materials used for 3D printing, testing of the materials and learning their real parameters. Goal of the thesis is comparing selected materials, executing series of mechanical test and selecting suitable material for printing high-quality plastic parts for use in automobiles, especially for reproduction of parts that are no longer made for oldtimers and for use in motorsport.
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The assesment of trombocyte function by optical and impendance agregometry
Malíková, Lenka ; Stiborová, Marie (advisor) ; Poljaková, Jitka (referee)
Introduction: Platelets have an important role in the process of haemostasis in which they form blood clot generation. In some cases it is necessary to suppress activity of platelets by antiplatelet drugs to prevent life threatening states. Acetylsalicylic acid (ASA) and clopidogrel can influence the mechanism of primary haemostasis by inhibition of platelet function. This process has to be controlled. Clopidogrel is used for prevention of thrombotic states. The active form of clopidogrel is formed by cytochrome P450 3A4. Clopidogrel binds to the receptor P2Y12 instead of ADP, so platelets cannot be activated. The effect of clopidogrel is very variable. It is known that there is unresponsiveness to clopidogrel in 5-30 % patients. Acetylsalicylic acid acetylates cyclooxygenase and blocks the conversion of arachidonic acid to tromboxan A2, so platelets cannot be activated. ASA treatment is effective, but in some patients can appear so called aspirin resistance (AR). Possible unresponsiveness to the therapy is the reason why it is suitable to monitor antiplatelet therapy, which may be provided by various methods. Thesis target: To detect normal range in measurement of healthy control group, evaluate efficiency of clopidogrel and ASA and to determine which method (LTA - Light Transmission Aggregometry...
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Ecotoxicological Evaluation of Polymers and Biologically Active Substances in Aquatic Environments
Kašpar, Otakar ; Beklová, Miroslava (referee) ; Chýlková, Jaromíra (referee) ; Kráčmar, Stanislav (referee) ; Vávrová, Milada (advisor)
To determine the ecotoxicity of analgetics, first the individual ecotoxicity values of individual analgetics are determined and then a mixture of two analgetics is tested. To determine the toxicity, both standard and alternative toxicity tests are used (daphnia magna, sinapsis alba, scenedesmus subspicatum, vibrio fischeri, thamnotoxkit FTM a daphnotoxkit FTM magna). The analgetics being whish tested are the commonly used medicines ibuprofen, ASA, diclofenac and paracetamol, which are the most frequently used medicines in the Czech Republic and whole Europe. To determine the ecotoxicity of the polymers, I‘m using an indirect method of examination, in which I determine the antagonistic or synergistic effects of the mixture of monomers from which the polymer is prepared and into which it slowly decomposes in nature. For the determination both standard and alternative toxicity tests are used. The polymers the toxicity of which is being determined are the habitually used polymer PET and the formaldehyde resine known as bakelite in Eastern Europe.
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Network protection testing and DoS attacks protection
Hanzal, Jan ; Šilhavý, Pavel (referee) ; Hajný, Jan (advisor)
The aim of this Master thesis is a testing of Cisco ASA\,5510 firewall with affect of Denial of Service attacks. Part of the thesis is a teoretical description some of the attacks and practical tests. Practical part covers basic testing of Cisco ASA with Spirent Avalanche 3100B. Number of TCP connections per second and firewalls throughput on 7th layer of ISO/OSI model were tested. Also the effect of Denial of Service attacks on the throughput. In a next part there is described one possible way how to generate Denial of Service attacks from a Linux server to the firewall. Python scripts were used for generation DoS packets. With those scripts it is possible to generate five types of attacks.
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