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Design of technology for gear manufacturing
Urbánek, Michal ; Píška, Miroslav (referee) ; Sliwková, Petra (advisor)
The master’s thesis is focused on the design of production technology and the choice of machines and tools to achieve the required accuracy according to the drawing documentation. During the design of production options, the advantages and disadvantages of gear machining variants were described. In the theoretical part, the technologies of the proposed operations were described, such as turning, milling of gears in a rolling method, shaving and grinding. In the practical part, the production itself is described in all sixteen operations that were needed to produce the part. Instructions and tables of measured dimensions were created for each machine operation. The economic evaluation summarizes material costs, machine and preparation times depending on the size of the production batch.
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Design of material handling between the planned interimwarehouse and welding shops using dynamic simulation
Vícha, Ondřej ; Urbánek, Michal (referee) ; Hloska, Jiří (advisor)
This master thesis deals with optimizing material and information flow between the production plants and warehouses during the reconstruction of the manufacturing plant of Schäfer in Hranice na Moravě. At first, a theoretical introduction to the issues of inter-company transport services is presented. This introduction is followed by an analysis of the current state of material and information flow at the manufacturing plant. The practical part of the thesis consists of a simulation model made in the Tecnomatix plant simulation program. This simulation model includes the plant's current and future states and a layout of future material flow between the welding shops and warehouses. It also contains a conceptual design of the material flow. The optimization is conducted using a matrix of experiments, which are subsequently evaluated. In the end, the most optimal solution for material and information flow is developed and suggested.
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Spin wave excitation and propagation in magnonic crystals prepared by focused ion beam direct writing
Křižáková, Viola ; Olejník,, Kamil (referee) ; Urbánek, Michal (advisor)
Paramagnetické niklem stabilizované tenké vrstvy plošně centrovaného kubického Fe, epitaxně narostené na monokrystalickém substrátu Cu(100) jsou známy svou schopností strukturní a magnetické fázové přeměny při ozáření iontovým svazkem, a to do prostorově centrované kubické struktury charakteristické feromagnetickými vlastnostmi. Monokrystalický Cu(100) substrát je možné také nahradit Si(100) s mezivrstvou Cu(100). Pomocí fokusovaného iontového svazku lze dále snadno lokálně modifikovat magnetické vlastnosti ozařované vrstvy. Tato metoda přímého zápisu magnetických struktur je alternativou k běžným litografickým technikám, nabízející nové jimi nedosažitelné možnosti. Připravené magnetické struktury následně využíváme k propagaci spinových vln. V práci je představen celý proces od růstu vrstev, přes přípravu mikrostruktur, až po studium jejich struktury a statických i dynamických magnetických vlastností. S využitím vektorového síťového analyzátoru studujeme ve vrstvách a v mikrostrukturách připravených fokusovaným iontovým svazkem feromagnetickou rezonanci a propagující se spinové vlny. Zdrojem spinových vln o definovaných vlnových vektorech jsou litograficky připravené koplanární vlnovody, sloužící také k induktivní detekci vln. Pomocí feromagnetické rezonance kvantitativně určujeme materiálové charakteristiky jako jsou saturační magnetizace a parametr útlumu a ze spekter propagujících módů následně určujeme charakteristiky spinových vln, které porovnáváme s dalšími feromagnetickými materiály.
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Study of magnonic crystals in a frequency domain
Turčan, Igor ; Hrabec, Aleš (referee) ; Urbánek, Michal (advisor)
Popis magnetodynamických vlastností nanomagnetů a nanostrukturovaných magnetických materiálů vyžaduje metody vhodné pro zkoumání typické časové odezvy těchto systémů, tj. v řádu nanosekund a méně. Nedostatek technik, vhodných právě pro charakterizaci v časové doméně, je spojen s možnostmi současné elektroniky. Další možný přístup, jak popsat vlastnosti nanomagnetů, je charakterizace ve frekvenční doméně v pásmu GHz. Nejrozšířenější technikou charakterizace ve frekvenční doméně je měření feromagnetické rezonance (FMR). Ze spekter FMR lze získat cenné informace o systému: parametr tlumení, saturační magnetizace atd. Metoda, kterou využíváme k detekci excitací spinových vln, má za cíl zjednodušení charakterizace. Využíváme termoelektrickou detekci spinových vln v magnetických drátech prostřednictvím anomálního Nernstova jevu. Metoda je založena na disipaci tepla uvnitř magnetické vrstvy v důsledku útlumu spinových vln, a proto dochází k vytvoření teplotního gradientu směrem k substrátu (kolmo k povrchu). To vede k vytvoření elektrického pole kolmého jak na teplotní gradient, tak na směr magnetizace. Napětí je obvykle v řádu V, proto může být měřeno obvyklým laboratorním vybavením. Navzdory své jednoduchosti poskytuje tato metoda velmi zajímavé výsledky a může být použita pro charakterizaci magnonických vlnovodů, magnonických metamateriálů, emitorů spinových vln a dalších zařízení, pracujících se spinovými vlnami.
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Spin vortex states in magnetostaticaly coupled magnetic nanodisks
Vaňatka, Marek ; Hrabec, Aleš (referee) ; Urbánek, Michal (advisor)
Magnetic vortices in ferromagnetic disks are curling magnetization structures characterized by the sense of the spin circulation in the plane of the disk and by the direction of the magnetization in the vortex core. Concepts of memory devices using the magnetic vortices as multibit memory cells have been presented, which brought the high demand for their research in many physical aspects. This work investigates the magnetostatic coupling in pairs of ferromagnetic disks to clarify the influence of nearby disks or other magnetic structures to the vortex nucleation mechanism. To ensure that the vortex nucleation is influenced only by the neighbouring magnetic structures, the randomness of the nucleation process was studied in single disks prior to the work on pairs of disks. We had to ensure that the vortex nucleation is influenced only by the neighbouring magnetic structures and not by an unwanted geometrical asymmetry in the studied disk. Lithographic capabilities were inspected in order to achieve the best possible geometry. Further we present a concept of electrical readout of the spin circulation using the anisotropic magnetoresistance, which allows automated measurements to provide sufficient statistics. To explain the magnetoresistance behaviour, numerical calculations together with magnetic force microscopy measurements are presented.
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Automation and control of multilayers deposition by IBS/IBAD
Pavera, Michal ; Sobota, Jaroslav (referee) ; Urbánek, Michal (advisor)
This diploma thesis deals with the automation of the deposition process by ion beam sputtering and ion beam assisted deposition. This work contains drawings of mechanical adjustments of the deposition chamber designed to control shutter and rotation of the target using stepper motors. There are presented ways to control stepper motors and troubleshoot their exact settings. Another task is to design a system for computer control of the deposition process. There are discussed ways to control the ion sources, pressure meter, flow meter and thickness meter, and their connection to a PC via RS-232 and analog-digital converters. It is also designed control program in LabVIEW, which allow automated multilayer deposition. Last part of the thesis deals with testing automatic deposition and results are commented.
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Managing Risk when Implementing Changes
Anca, Marek ; Urbánek, Michal (referee) ; Kruliš, Jiří (advisor)
This diploma thesis put its focus on dealing with risk management issues during the implementation of changes in a particular company with a focus on the human factor. The literature research is devoted to a professional description of topics related to the research issues of this diploma thesis. The following part describes the methods that were used to achieve the goal of the thesis. The next part distinguish the analysis of the current situation of the company, the design of measures that would minimize most of the risk factors and processes of the company. The last part presents a project for which risks are identified and possible measures are proposed in order to increase the probability of success.
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Variable Field Magnetic Force Microscopy
Turčan, Igor ; Nováček, Zdeněk (referee) ; Urbánek, Michal (advisor)
The bachelor's thesis deals with magnetic force microscopy of permalloy discs in an external magnetic field. Main objectives of the thesis are design of an external magnetic field module, preparation of magnetic probes, fabrication of samples and the measurement itself. We prepared functional probes with various magnetic coatings. For the measurement in external magnetic field we fabricated probes with a~layer of magnetically hard Co and for the measurement without external magnetic field we used probes with a~layer of magnetically soft permalloy. Our probes are at least comparable with standard commercial probes. We observed the cores of magnetic vortices, using our home-coated probes with no external magnetic field and also in the external magnetic field. Further, we study the influence of the external magnetic field on nucleation of the cores of magnetic vortices. Experimental techniques used for fabrication and measurement of the samples are briefly summarized.
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Study of magnetic nanostructures for spintronics
Kameš, Jaroslav ; Nebojsa, Alois (referee) ; Urbánek, Michal (advisor)
The Cu/NiFe/Cu/Co/(CoOx) spin-valves have been prepared by the ion-beam sputtering method. Their GMR ratio and the time stability have been investigated by the magnetoresistance and the MOKE measurements at room temperature. The reproducibility of the preparation of the samples have been studied as well, i.e. two identically configurations of the layers should have the same magnetotransport properties.
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Tracked vehicle for working on a slope
Těšický, Petr ; Urbánek, Michal (referee) ; Kašpárek, Jaroslav (advisor)
This bachelor thesis deals with the conceptual design of a remotely controlled tracked vehicle for work on a slope. In the first part, a short research analysis of remotely controlled tracked vehicles is performed. During the design of the concept itself, dimensional, force and power calculations are performed. The design of some components is based on these calculations. Strength calculations for certain components are performed in the last part of this work. The result is a conceptual design of a remotely controlled tracked vehicle.
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