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Design of apparatus for anodizing aluminum alloys
Prokop, Adam ; Hurník, Jakub (referee) ; Košťál, David (advisor)
This thesis deals with the problem of anodizing aluminium and its alloys. The aim of the thesis was to design a compact anodizing apparatus for laboratory conditions for components with maximum dimensions of 200 x 100 x 100 mm. All goals of the thesis were met, the outputs of the thesis are design of the apparatus, assembly drawing and fully functional device.
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Reflex of Space
Šrom, Samuel ; František,, Dvořák (referee) ; Korbička, Pavel (advisor)
The diploma thesis named Reflections of Space aims to change the approach at material anodizing and to move this purely technological process to the artistic level. The first part of the thesis summarises concisely a process of anodising and seeks for its demonstrations in the field of culture. The second part of the thesis describes the intention itself and the results of the research in the framework of technological proofs which are presented in the figurative part of the thesis.
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Gas Microsensors Based on Self-Organized 3D Metal-Oxide Nanofilms
Pytlíček, Zdeněk ; Husák, Miroslav (referee) ; Kolařík, Vladimír (referee) ; Prášek, Jan (advisor)
This dissertation concerns the development, fabrication and integration in a gas sensing microdevice of a novel 3-dimensional (3D) nanostructured metal-oxide semiconducting film that effectively merges the benefits of inorganic nanomaterials with the simplicity offered by non-lithographic electrochemistry-based preparation techniques. The film is synthesized via the porous-anodic-alumina-assisted anodizing of an Al/Nb metal bilayer sputter-deposited on a SiO2/Si substrate and is basically composed of a 200 nm thick NbO2 layer holding an array of upright-standing spatially separated Nb2O5 nanocolumns, being 50 nm wide, up to 900 nm long and of 8109 cm2 population density. The nanocolumns work as semiconducting nano-channels, whose resistivity is greatly impacted by the surface and interface reactions. Either Pt or Au patterned electrodes are prepared on the top of the nanocolumn array using an innovative sensor design realized by means of microfabrication technology or via a direct original point electrodeposition technique, followed by selective dissolution of the alumina overlayer. For gas-sensing tests the film is mounted on a standard TO-8 package using the wire-bonding technique. Electrical characterization of the 3D niobium-oxide nanofilm reveals asymmetric electron transport properties due to a Schottky barrier that forms at the Au/Nb2O5 or Pt/Nb2O5 interface. Effects of the active film morphology, structure and composition on the electrical and gas-sensing performance focusing on sensitivity, selectivity, detection limits and response/recovery rates are explored in experimental detection of hydrogen gas and ammonia. The fast and intensive response to H2 confirms the potential of the 3D niobium-oxide nanofilm as highly appropriate active layer for sensing application. A computer-aided microfluidics simulation of gas diffusion in the 3D nanofilm predicts a possibility to substantially improve the gas-sensing performance through the formation of a perforated top electrode, optimizing the film morphology, altering the crystal structure and by introducing certain innovations in the electrode design. Preliminary experiments show that a 3D nanofilm synthesized from an alternative Al/W metal bilayer is another promising candidate for advanced sensor applications. The techniques and materials employed in this work are advantageous for developing technically simple, cost-effective and environmentally friendly solutions for practical micro- and nanodevices, where the well-defined nano-channels for charge carriers and surface reactions may bring unprecedented benefits.
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Nanoelectrodes for biophysical measurements
Márik, Marian ; Hrdý, Radim (referee) ; Hubálek, Jaromír (advisor)
The aim of the project is formation of nanoelectrodes on the silicon wafer surface by thin-film techniques combined with lithography and nanotechniques developed in LabSensNano. Project is engaged in lithography and in preparation of silicon wafers. Furthermore is proposed a brief proposal of electrodes, proposal of realization and current state of the experiment.
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Impact of input parameters variation on fabrication of nanoporous alumina
Hriczo, Filip ; Macháčková, Marina (referee) ; Hrdý, Radim (advisor)
This thesis examines and tests acids and conditions, which make the production of nanoporous ceramic at the thin aluminium layer the most effective and provide the highest quality. This paper describes the production of nanoporous structures with pore size 15-400 nm, depending on the electrolyte. Creating a regular hexagonal structure by electrochemical oxidation is dependent on many parameters that affect the regularity of structure and parameters of the ceramics produced. They were investigated primarily by changes in temperature and input voltage. All results were examined by SEM analysis.
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Surface treatments of internal combustion engines cylinders
Malec, Petr ; Raffai, Peter (referee) ; Maršálek, Ondřej (advisor)
This bachelor thesis is a professional research, which describes the most common methods of surface treatments of modern internal combustion engines cylinders. The work consists of the distribution of the species changes, their use and justification of their application. It also describes the technology of individual surfaces, their coating and finishing operations to achieve the best results of sliding surface.
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Design of universal wire bending machine
Nezval, Jan ; Svoboda, Pavel (referee) ; Brandejs, Jan (advisor)
This bachelor’s degree thesis deals with the specification, design and subsequent construction of a CNC wire bending machine for use with aluminium alloys. The machine is designed for bending suspension hooks and tension springs for use in anodizing processes. This thesis also briefly describes the anodizing process, outlines specifics of the suspension parts, the current state of the wire bending machine market and the solution design. Finally there is a breakdown of the individual parts.
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