|
|
Design of the test rig for the observations of the lubricant distribution in the rolling bearing
Okál, Michal ; Hartl, Martin (referee) ; Košťál, David (advisor)
Given diploma thesis deals with the design and realization of a device whose purpose is to simulate real condition in the contact area of deep groove ball bearings. Direct observation of such area was then carried out. Initial part of the thesis addresses principles occurring in ball bearings, such as friction and lubrication and wear mechanisms. Several devices which are commonly used for bearing lubrication studies are then described at the work. Subsequently, author’s solution was introduced with the output of Ball-on-ring device. Ball-on-ring configuration is key feature due to its geometry since it enables to create identical conditions as those which occur in ball bearings such as contact pressure and velocities. Lubricant distribution by the contact area is analysed with fluorescent microscopy. Part of this thesis is a validation experiment and drawing documentation of the device.
|
|
|
Experimental observation of grease migration in a rolling bearing simulator
Palán, Miroslav ; Okál, Michal (referee) ; Košťál, David (advisor)
This thesis is using fluorescence microscopy to separately observe components of grease lubricate in simulator of ball rolling bearing. Simulator is in the configuration ball-on-disk when the disk was replaced by the outside ring made by tempered glass. This ring allows light passing to normally unseeable places of steel bearing. By the separate study of greases particles, coloured with special fluorescent dye, was found that method of fluorescence microscopy can be used to gain information about grease lubricated process in bearing.
|
|
|
The Effect of Synovial Fluid Constituents on Lubrication of Hip Joint Replacements
Nečas, David ; Daniel,, Matej (referee) ; Sawae, Yoshinori (referee) ; Hartl, Martin (advisor)
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.
|
|
|
Design of knee joint simulator
Polnický, Vojtěch ; Čížek, Petr (referee) ; Vrbka, Martin (advisor)
The diploma thesis is focused on the design and realization of an experimental device. The purpose of device is the simulation of dynamic and kinematic conditions of knee replacement during the walking cycle. The simulator will be used to study the formation of the lubricating film in contact of the femoral component and the polyethylene spacer, and to the cyclic wear tests for knee replacements. First part of thesis is focused on the description of working parameters of knee replacements and analysis of knee joint simulators. The description of conceptual design and selection of the final variation follows. The final design allows simulation of dynamic and kinematic conditions of ISO 14 243-3. Creation of lubricating film is analyzed by the non-contact optical fluorescence microscopy method. The work includes complete drawing documentation, wiring diagram, verification of the functionality of the device and detailed operating instructions.
|
|
|
Design of a simulator for studying eye friction and lubrication
Snopek, Lukáš ; Horák, Zdeněk (referee) ; Vrbka, Martin (advisor)
This work deals with the design of a tribometer, which simulates the interaction between the human eye and the eyelid, and simultaneously measures the friction between them and the thickness of the tear film. The tribometer will be used for research and development of artificial tears based on hyaluronic acid. The aim of the work was to design experimental conditions, conceptual and design solutions, as well as to ensure the production, assembly, and validation of the device. The experimental conditions were determined based on critical research. Four different conceptual solutions were proposed, of which two were selected for further development in the design solution. Based on the engineering documentation, the production of non-standardized components and assembly were ensured. Validation experiments demonstrated that the simulator enables the measurement of friction and tear film thickness at the contact area under the desired conditions, with both conforming and non-conforming types of contact. The contribution of this work lies in the construction of a new device that allows for measuring the coefficient of friction and film thickness during conforming contact, offering new opportunities in the study of human eye biotribology.
|
|
|
Experimental observation of grease migration in a rolling bearing simulator
Palán, Miroslav ; Okál, Michal (referee) ; Košťál, David (advisor)
This thesis is using fluorescence microscopy to separately observe components of grease lubricate in simulator of ball rolling bearing. Simulator is in the configuration ball-on-disk when the disk was replaced by the outside ring made by tempered glass. This ring allows light passing to normally unseeable places of steel bearing. By the separate study of greases particles, coloured with special fluorescent dye, was found that method of fluorescence microscopy can be used to gain information about grease lubricated process in bearing.
|
|
|
Flow cytometry in the diagnostics and characterization of congenital disorders of glycosylation
Veselá, Šárka ; Hansíková, Hana (advisor) ; Hodek, Petr (referee)
Congenital disorders of glycosylation (CDG) are rare multisystem metabolic diseases and their number has rapidly grown in recent years. The clinical manifestation includes very broad spectrum of symptoms. In most of all cases CDG are caused by mutations in genes encoding the enzymes of glycosylation pathway. Based on the type of defect, CDG are divided into the following groups: disorders of N-glycosylation or O-glycosylation of proteins, defects in modification of proteins by GPI anchor, disorders of lipid glycosylation and defects that impact multiple glycosylation pathways. The aim of the thesis was to find new biochemical analyses suitable for diagnostics and characterization of CDG patients. The experimental conditions were optimized for selected markers (Sambucus Nigra (SNA) lectin, proaerolysin (FLAER), antibodies to proteins CD55 and CD59) and the staining was applied to cultivated skin fibroblasts from controls and patients diagnosed with CDG by whole-exome sequencing (ATP6AP1-CDG, PIGN-CDG, SLC10A7-CDG, PISD deficiency). The experiments were performed using flow cytometry (FACS) and fluorescent microscopy (FM). The detection of sialylation by SNA lectin and analysis of the mitochondrial membrane potential changes by a fluorescent labelled probe JC-1 with FCCP simulation of mitochondrial...
|
|
|
Structure and dynamics of mouse C-type lectin-like receptors.
Wallenfels, Lucie
Natural killer (NK) cells represent indispensable part of the innate immunity as they are capable of promptly identifying virally infected or tumor cells and participating in the regulation of adaptive immune responses. These functions are ensured by the interplay between NK receptors, creating a complex regulatory system. Solving the receptors' structure may contribute to an overall understanding of NK cell biology. Presented thesis describes an elucidation of the structure of the inhibitory C-type lectin-like receptor (CTLR) Nkrp1b with an emphasis toward structural features (stalk, loop and oligomerization state) which might affect conformation or interactions of this receptor. The interaction of Nkrp1b with its ligand, Clr-b protein, is immunologically significant as it regulates NK cells' activity independently and monitors changes that are not visible to cytotoxic T lymphocytes. To study individual structural aspects of Nkrp1b, two protein variants were recombinantly prepared in bacterial expression system: entire ectodomain and ligand-binding domain lacking the stalk. Using a range of mass spectrometric techniques in combination with homology modeling and molecular dynamics, we proposed the Nkrp1b structure including its monomeric and dimeric arrangements. In addition, the oligomerization...
|
|
|
Design of the test rig for the observations of the lubricant distribution in the rolling bearing
Okál, Michal ; Hartl, Martin (referee) ; Košťál, David (advisor)
Given diploma thesis deals with the design and realization of a device whose purpose is to simulate real condition in the contact area of deep groove ball bearings. Direct observation of such area was then carried out. Initial part of the thesis addresses principles occurring in ball bearings, such as friction and lubrication and wear mechanisms. Several devices which are commonly used for bearing lubrication studies are then described at the work. Subsequently, author’s solution was introduced with the output of Ball-on-ring device. Ball-on-ring configuration is key feature due to its geometry since it enables to create identical conditions as those which occur in ball bearings such as contact pressure and velocities. Lubricant distribution by the contact area is analysed with fluorescent microscopy. Part of this thesis is a validation experiment and drawing documentation of the device.
|
|
|
Structure and dynamics of mouse C-type lectin-like receptors.
Wallenfels, Lucie
Natural killer (NK) cells represent indispensable part of the innate immunity as they are capable of promptly identifying virally infected or tumor cells and participating in the regulation of adaptive immune responses. These functions are ensured by the interplay between NK receptors, creating a complex regulatory system. Solving the receptors' structure may contribute to an overall understanding of NK cell biology. Presented thesis describes an elucidation of the structure of the inhibitory C-type lectin-like receptor (CTLR) Nkrp1b with an emphasis toward structural features (stalk, loop and oligomerization state) which might affect conformation or interactions of this receptor. The interaction of Nkrp1b with its ligand, Clr-b protein, is immunologically significant as it regulates NK cells' activity independently and monitors changes that are not visible to cytotoxic T lymphocytes. To study individual structural aspects of Nkrp1b, two protein variants were recombinantly prepared in bacterial expression system: entire ectodomain and ligand-binding domain lacking the stalk. Using a range of mass spectrometric techniques in combination with homology modeling and molecular dynamics, we proposed the Nkrp1b structure including its monomeric and dimeric arrangements. In addition, the oligomerization...
|
guest ::
