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Mapování tloušťky mazacího filmu u náhrad velkých kloubů člověka / Mapping of lubricating film thickness of human big joints replacementsBosák, Dalibor January 2012 (has links)
This master’s thesis describes mechanism of lubricating film forming and its thickness in contact of a metal hip joint ball and a glass disc with chromium layer with presence of bovine serum as substitute of synovial fluid occured in a natural joint. Lubricating film thickness is evaluated by a thin film colorimetric interferometry, results are ploted at graphs representing dependence of lubricating film thickness on experiment duration or on mutual speed of articulating surfaces. There is described the influence of concentration of bovine serum and different kinematic conditions on lubricating film forming. From observed interferograms is apparent the adsorption of proteins to glass disc and femoral head surfaces, denaturation and formation of protein aggregations affecting the residual lubricating film thickness.
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Zařízení pro měření vlnoplochy mikroskopových objektivů / Device for wavefront measurement of microscope objective lensesBartoníček, Jan January 2013 (has links)
The wavefront reconstruction of a light wave transformed by a microscope objective is the main subject of this diploma thesis together with the design and assembly of a~measuring device and the development of a computational algorithm. The purpose is to determine optical aberrations and to compare a quality of objectives with identical parameters. The term wavefront is explained and its description using Zernike polynomials is introduced in the first part of the thesis. The following part summarizes possible methods for wavefront reconstrucion. Two methods were chosen for experimental determination of a wavefront shape – shearing interferometry and solution of the transport of intensity equation. For each method a brief characteristic is provided together with possible applications, mathematical apparatus, image processing, computational procedure, setup description and proposition and results of experiments. The suitability of both methods for optical aberration determination and microscope objective comparison is discussed. Based on the obtained results, both methods were found to be suitable for comparison of microscope objectives. The suitability for optical aberration determination is possible with certain restrictions.
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Experimentální studium mazání okolku kolejových vozidel / Experimental Study of Wheel Flange LubricationFrýza, Josef January 2013 (has links)
This diploma thesis deals with the experimental study of the influence of operating conditions on the tribological aspects of the wheel flange and rail gauge contact. The wheel flange contact occurs when the vehicle moves on a curve track and it leads to severe up to catastrophic wear regime. For effective reduction of wear is important to apply a suitable amount of lubricant at appropriate intervals into the contact. The issue in this work comprehensively studies using of three laboratory apparatus and six methods that are theoretically and experimentally compared. Assessed are friction, wear, distribution and film thickness of lubricants for different contact conditions. The resulted amount of lubricant and interval of its application eliminates development of seizure at low consumption of lubricant. The understanding of mechanisms that occur in the wheel-rail contact not only helps to reduce operating costs and improved to energy efficiency of movement of vehicle on a track, but it is the basis for safe, reliable and ecological operation of rail transport.
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Experimentální studium tření a mazání TEP kyčle / Experimental study of friction and lubrication in THRUrban, Filip January 2014 (has links)
This work analyzes problems of friction and lubrication of total hip replacement (THR). At first, experimental study of friction coefficient under various conditions was conducted using hip joint simulator based on principle of pendulum. After that, lubrication film development was observed, using colorimetric interferometry with head from THR and glass cup with respect of geometry and clearance to cups made originally for THR. With respect to research study [25] it was found that increasing contact conformity leads to increased film thickness. Also protein adsorption on articulating surfaces was observed. Thanks to adsorption 80 nm film thickness was measured even if relative surface speed was zero. Furthermore protein aggregation was observed on the border of contact zone, similar aggregations were observed by Myant et al. [29] or Vrbka et al. [25]. These aggregations are formed when lubricant is under shear stress and it can positively affect film thickness. If the relative motion of articulating surfaces is not sufficient, the protein layer can`t be refreshed enough and film thickness start decreasing. Coefficient of friction 0,13 was measured when lubricating film development was observed. Close to this value are material combinations metal on polyethylene and metal on metal.
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Měření parametrů textury povrchu výrobků kontaktní a bezkontaktní metodou / Measurement of Surface Texture Parameters of Products Using Contact and Non-contact MethodsHarčarík, Matej January 2016 (has links)
This master’s thesis includes an overview of profile method of surface texture evaluation according to ISO standards and VDA automotive standards, as well as an overview of areal method according to ISO 25178 standard series, which includes a proposal for improvement of czech terminology. Suitability of application of selected measurement methods for measurement of a portfolio of automotive parts was evaluated based on measurements carried out using a contact profiler, a coherence scanning interferometer and a confocal microscope. Further recommendations for practice in surface texture metrology were also formulated. A regression analysis of the relationship between values of selected profile surface texture parameters and their areal equivalents was also performed. Its results may aid the spread of areal surface texture evaluation in the industry.
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Konstrukce simulátoru kyčelního kloubu / Design of hip joint simulatorŽonda, Peter January 2016 (has links)
The master's thesis is concerned with design and execution of an experimental acetabulofemoral joint simulator. Its primary use is the study of lubrication film thickness in hip implants. The work first describes available hip joint simulators, which simulate particular joint positions. Next, the thesis proposes author’s own designs and solutions. The result is a produced device allowing for dynamic change of load in simulation of hip joint flexion and extension as set by ISO standard. Contact is recorded by an optical apparatus composed of a high-speed camera and a microscope. The work also includes the initial testing experiment and the complete design documentation of the device including electrical wiring diagrams.
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Konstrukce odměřovacího systému pro systém reaktivního iontového leptání / Mechanical design of measurement system for reactive ion etching systemMaňka, Tadeáš January 2016 (has links)
The aim of this work is to design fully working measuring system for the reactive ion etching system (RIE). The Michelson interfometer, previously developed in Ústav přístrojové techniky, v.v.i., is used in this work. The theoretical part is aimed at description of interferometric methods for precise measuring of length. In next part the etching proces with RIE is described. In practical part the testing system was constructed from the parts of Thorlabs company . The functionality was controlled with this system and the results of measuring were compared with the profilometer. In next step technical drawings were created and the whole system was made.
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The Effect of Synovial Fluid Constituents on Lubrication of Hip Joint Replacements / The Effect of Synovial Fluid Constituents on Lubrication of Hip Joint ReplacementsNečas, David January 2016 (has links)
Dizertační práce se zabývá mechanismy mazání v náhradách kyčelního kloubu. Byla provedena systematická studie formování proteinového filmu při zahrnutí různých materiálů a provozních podmínek. Hlavní pozornost je přitom věnována roli jednotlivých proteinů obsažených v synoviální kapalině při současné přítomnosti dalších proteinů. Jelikož metody aplikované v předchozích studiích neumožňovaly separovat jednotlivé složky maziva, byla vyvinuta optická měřící metoda na principu fluorescenční mikroskopie. Z důvodu verifikace metody byly provedeny dvě nezávislé studie zaměřené na měření tloušťky mazacího filmu a dělení maziva na výstupu mazaného kontaktu. Z důvodu určitých limitací fluorescenční mikroskopie byla dále využita i metoda optické interferometrie, jejíž využití je ilustrováno ve studii zabývající se formováním mazacího filmu v náhradách kyčelního klubu při uvažování reálné konformity třecích povrchů. Závěrečná část práce představuje nový metodologický přístup založený na in situ pozorování kontaktní oblasti umožňující popsat roli jednotlivých proteinů ve vztahu k vývoji tloušťky mazacího filmu. Práce obsahuje originální výsledky, které přináší nové poznání v oblasti biotribologie náhrad kyčelního kloubu vedoucí k dalšímu vývoji implantátů při snaze zabránit jejich selhání v důsledku omezené životnosti.
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Automatizované procedury pro Koherencí řízený holografický mikroskop / Automated Procedures for Coherence Controlled Holographic MicroscopeDostál, Zbyněk January 2016 (has links)
Coherence-Controlled Holographic Microscope (CCHM) and a Fluorescence Holographic Microscope (FHM) were developed particularly for quantitative phase imaging and measurement of live cell dynamics, which used to be a subject of digital holographic microscopy (DHM). CCHM and FHM in low-coherence mode extend capabilities of DHM in the study of living cells. However, this advantage following from the use of low coherence is accompanied by increased sensitivity of the system to its correct alignment. Therefore, the introduction of an automatic self-correcting system is inevitable. Accordingly, in the thesis, the theory of a suitable control system is derived and the design of an automated alignment system for both microscopes is proposed and experimentally proved. The holographic signal was identified as a significant variable for guiding the alignment procedures. On this basis the original basic realignment algorithms were proposed, which encompasses the processes for initial and advanced alignment as well as for long-term maintenance of the microscope aligned state. Automated procedures were implemented in both microscopes unique set of robotic mechanisms designed and built within the frame of the thesis work. All of the procedures described in the thesis were in real experimentally proved at real microscopes in the experimental biophotonics laboratory. In addition, the control software, which contains the needed automated procedures, was developed for FHM.
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Caractérisation 3D d’un nuage de particules par imagerie interférométrique de Fourier : positions relatives 3D, tailles et indices de réfraction / 3D characterization of a cloud of particles by Fourier interferometric imaging : 3D relative positions, sizes and refractive indicesBriard, Paul 05 December 2012 (has links)
Dans ce mémoire, je propose une nouvelle technique optique de mesure de positions relatives 3D, tailles et indices de réfraction d’un ensemble de particules, éclairées par un faisceau laser plan pulsé : l’imagerie interférométrique de Fourier (FII). Dans le cadre de ce travail, les particules sont sphériques, homogènes transparentes et isotropes. Lorsque ces particules sont éclairées, elles se comportent comme des sources d’ondes lumineuses sphériques qui interférent entre elles. L’enregistrement des franges d’interférences et leur analyse par transformation de Fourier peut permettre d’accéder aux caractéristiques des particules. Dans ce mémoire, je décris l’influence des caractéristiques de particules sur les représentations spectrales des franges d’interférences crées par les couples de particules éclairées dans l’espace de Fourier 2D. Les franges d’interférences sont simulées numériquement en utilisant la théorie de Lorenz-Mie. Puis j’aborde le problème inverse en montrant comment il est possible de retrouver les caractéristiques des particules, en me servant de l’optique géométrique et du filtrage spatial par transformation de Fourier. / In this thesis, I propose a new optical technique for measuring 3D relative positions, sizes and refractive indices of a set of particles, which are illuminated by a plane and pulsed laser beam. In this work, the particles are spherical, transparent, homogeneous and isotropic. When these particles are illuminated, they have the behavior of sources of spherical light waves which interfere. The recording of interference fringes and analysisby Fourier transform can measure the characteristics of the particles. I describe the influence of particle characteristics on spectral representations of the interference fringes created by the pairs of particles illuminated in 2D Fourier space. The interference fringes are simulated numerically using the Lorenz-Mietheory. The inverse problem is approached by showing how it is possible to measure the characteristics of particles with geometrical optics and spatial filtering by Fourier transformation.
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