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SMV-2023-42: Materials for thermal management
Králík, Tomáš
This contract research dealt with so-called solar white coatings with a very different ability to absorb visible radiation and emit thermal radiation. We have studied special coatings designed for the space environment with high emissivity in the field of thermal radiation and at the same time low absorption of radiation originating from the sun or reflected from cosmic bodies. This type of coating is intended for passive thermoregulation of parts of apparatus moving in the space environment. The aim was to determine the so-called total hemispheric emissivity of each of the samples at the required temperatures. For these coatings, the client's goal was also to evaluate the effect of the morphology of the sample on the resulting emission of thermal radiation. Namely, we tested the flat and pyramidal structured surface of the base material. This unique research required a special modification of the supplied samples, modification of the dedicated method for measuring emissivity and absorptivity at cryogenic temperatures, as well as a new procedure for calibration and evaluation of the received data. We used a previously developed shielding ring around the perimeter of the samples to cover the perimeter of the structured samples, which prevented part of the measured thermal radiation from escaping. The results of this research will be used in the design of the CO2M space mission for monitoring CO2 emissions.
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SMV-2023-41: Absorptive coatings for quantum computers
Králík, Tomáš
This contract research focused on the thermal analysis of absorptive layers created by anodic oxidation on aluminium alloy, which are optimized for use at extremely low temperatures. These specific layers were designed for the low-temperature parts of quantum computers, where they play a key role in eliminating the reflection of thermal radiation from the hotter areas of the computer cryostat to the ultra-low temperature areas. Other key requirements for these absorptive layers are high thermal conductivity, necessary for efficient heat transfer within a quantum computer, good mechanical stability and extremely low outgassing to ensure long-term functional behaviour of the layers in challenging low-temperature conditions. The goal of this research was not only to verify the total hemispheric emissivity of three specific types of coatings in the temperature range from 10 K to 300 K. In this case, emissivity is a suitable indicator of the thermal absorptive behaviour of the layer. A study of the emissivity of these layers in the entire spectrum of temperature conditions relevant for quantum computers was carried out. This extensive analysis was intended to provide an insight into the suitability of these absorptive layers for applications in the field of low-temperature technologies, with an emphasis on the requirements of quantum computers.
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Adhesion of bituminous binders to aggregate
Vlk, Petr ; Hýzl, Petr (referee) ; Varaus, Michal (advisor)
In 2005 the revised European standard 12697-11:2005 [1] was introduced offering a choice of three different methods. The static method described in part B has some similarities with the replaced Swiss standard for the determination of the affinity between bitumen and aggregates [2] and Czech standard for adhesions of asfalt binder to aggregates ČSN 73 6161 [3]. The result of this study is to compare the static method described in the [3] and a draft changes by Swiss research project [4] with the current revision of the European Standard 12697-11: 2005.
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Machinable bioceramic foams prepared by gelcasting method
Šťastný, Přemysl ; Částková, Klára (referee) ; Trunec, Martin (advisor)
Diploma thesis is focused on development of method for preparation individualized bioscaffolds prepared by milling of HA foam prepared by gel casting method and consolidated via epoxy curing reaction. Diploma thesis continues in bachelor thesis Modern processing methods of porous bioceramics. Literature search is filled in the newest knowledge from the field of bioactivity enhancement of scaffolds. Experimental part of diploma thesis described development of system for individualized scaffold manufacturing from HA suspension preparation, preparation of ceramic blocks used as material for machining to final blocks machining. Pressure strength of foam were evaluated, too. Chosen samples were coated with calcium polyphosphate coating for biological response enhancement. Coated samples were given for in-vivo test to partner university in Beijing under the terms of project FP7-NMP-2013-EU-China: "Bioscaffolds"
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New generations of PVD coatings
Kantar, Filip ; Kolář, Ladislav (referee) ; Jaroš, Aleš (advisor)
Bachelor thesis deals with methods of coating, cutting tools and a new generation of coatings. In the first part are listed and described basic coating methods. The next part is aimed on coating of PVD methods. In the third part are listed basic tool materials and their characteristics. The last part is focused on new generation of coatings, their application, properties and structures.
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Tools for threading and their use
Veselý, Václav ; Polzer, Aleš (referee) ; Sliwková, Petra (advisor)
The bachelor’s thesis Tools for threading and their use deals with issues connected to tools, the materials used and their usage in the field of mechanical engineering. Individual parts of the thesis cover types of tools for threading, methods of threading and materials suitable for tap making. Further, the range of monolithic milling taps in the producers’ supply is also analysed.
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Untersuchung von Strukturen und Beschichtungen für tribologisch optimierte Umformwerkzeugoberflächen für die Aluminiumfeinblechbearbeitung
Kořenek, Jakub ; Hänel, Thomas (referee) ; Blecha, Petr (advisor)
V rámci bakalářské práce je provedena rešerše ke stavu techniky z pohledu tribologie, tváření hliníku, povlakování, strukturování a v závěru rozdělení tribologických zkoušek a metod jejich hodnocení. V praktické části jsou vyhodnoceny už dříve provedené pokusy na oscilačním tribometru. Následně byly provedeny pokusy tažení pásu s ohybem a bez ohybu s různými parametry pro jednotlivé zkoušky. Testovány byly různé laserové struktury (křížové, liniové, bodové) s variací jejich hloubky a pokrytí vzorků. V závěru práce jsou výsledky pokusů zhodnoceny z pohledu opotřebení, koeficientu tření a stability tribologického systému v průběhu pokusu. Z výsledků vychází doporučení pro následující pokusy a možné oblasti aplikace jednotlivých struktur.
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Analysis of the surface after laser cutting
Narovec, David ; Sedlák, Josef (referee) ; Osička, Karel (advisor)
This diploma thesis discusses laser cutting and the consecutive surface treatment of cut parts. The theory of laser cutting is described in the first part of this thesis, including laser history and the laser emergence principle. Cut parameters and the influence of the laser cutting on the material are described later on. The next part describes the laser cutting technological possibilities and other laser technology utilization options are outlined. In the last theory part, metal surface treatment used in the experiment is covered. Coating thickness is evaluated in the practical part of this thesis, as well as roughness, microhardness, chemical microanalysis and metalography. The evaluation of the results achieved, and optimal surface treatment execution suggestions are addressed in the last part of this thesis.
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Introduction of the New Technology into the Company
Vondruška, Jiří ; Růčka, Pavel (referee) ; Šunka, Josef (advisor)
The work is focused on introduction of new technology to the company engaged in dyeing and finishing of textile materials. The aim is to determine whether the investment will be beneficial for the company. Therefore it is necessary to learn about functioning of the company, with market, that is about to enter, with the reasons for choosing of the specific technology, way of financing, but also with technology itself. Subsequently it is needed to determine whether the investment will be effective or not.
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