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The effect of surface condition of artificial joint cup on the friction coefficient
Černohlávek, Mikuláš ; Dočkal, Kryštof (referee) ; Nečas, David (advisor)
This bachelor’s thesis deals with the effect of microtextured surface of an artificial joint cup on a friction coefficient. The primary aim of this thesis was to compare friction coefficients of original and microtextured joint cups. Experimental measurements were made on pendulum hip joint simulator and results were evaluated in Matlab. Four types of femoral heads (CoCrMo, BIOLOX Delta, BIOLOX Forte and oxinium) and three types of lubricants (PBS, model synovial fluid and hyaluronic acid solution) were used during the measurements. The results show, that using PBS and synovial fluid leads to decrease of the coefficient of friction while using modified joint cup. We can assume that microtextured surface of artificial joint cup (separately or in combination with microtextured femoral head) could be a significant benefit for prolonging lifespan of implants.
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Conceptual design of a gear tester for space applications
Florián, Vojtěch ; Černohlávek, Mikuláš (referee) ; Košťál, David (advisor)
This bachelor thesis deals with the creation of a conceptual design of gears tester for space applications. The tester must simulate space conditions and test whether the gear can operate in those conditions. It is more important to test the wheel material than its geometry. The work is divided into theoretical and practical part. In the theoretical part, a search of current knowledge of the issue is created. The second part describes several conceptual designs of testers and their models. Subsequently, a concept that can most faithfully simulate real conditions in low orbit is selected and described in detail. The final design of this concept will facilitate the testing of gears and minimize their failure rate during operation.
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Biotribology of artificial tears for the treatment of dry eye syndrome
Černohlávek, Mikuláš ; Daniel, Matej (referee) ; Vrbka, Martin (advisor)
This master thesis is a part of the project TAČR TREND, which aim is the development of new ingredient for treatment of dry eye syndrome. Developed ingredient is derivative of hyaluronic acid, which is in this thesis compared with native hyaluronic acids and commercial eye drops. Aim of this thesis is to describe rheological and tribological properties of measured samples in terms of viscosity, mucoadhesivity and coefficient of friction. Coefficient of friction was measured on created tribological model of the eye in pin-on-plate configuration which represents physiologically relevant sliding speeds of blinking. Comparison with native hyaluronic acids and commercial products of eye drops showed, that derivative reaches higher values of viscosity, has mucoahesive properties and has low values of coefficient of friction. Those key parameters show that modification of hyaluronic acid is promising way for drug development for dry eye disease.
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Conceptual design of a polymeric gear tester in vacuum
Ptáček, Matyáš ; Šperka, Petr (referee) ; Černohlávek, Mikuláš (advisor)
The bachelor thesis deals with the conceptual design of a polymeric gear tester in vacuum. Using a test device, it is possible to test the coefficient of friction in gears. At the beginning of the work is described the issue of operating conditions of satellites in low orbit together with the effects that affect them. Subsequently, suitable polymeric materials are selected, and current publicly available test rigs are described. Based on the research, two conceptual designs are made, one of them is selected and described in detail at the end of the work.
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Conceptual design of a gear tester for space applications
Florián, Vojtěch ; Černohlávek, Mikuláš (referee) ; Košťál, David (advisor)
This bachelor thesis deals with the creation of a conceptual design of gears tester for space applications. The tester must simulate space conditions and test whether the gear can operate in those conditions. It is more important to test the wheel material than its geometry. The work is divided into theoretical and practical part. In the theoretical part, a search of current knowledge of the issue is created. The second part describes several conceptual designs of testers and their models. Subsequently, a concept that can most faithfully simulate real conditions in low orbit is selected and described in detail. The final design of this concept will facilitate the testing of gears and minimize their failure rate during operation.
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Conceptual design of a polymeric gear tester in vacuum
Ptáček, Matyáš ; Šperka, Petr (referee) ; Černohlávek, Mikuláš (advisor)
The bachelor thesis deals with the conceptual design of a polymeric gear tester in vacuum. Using a test device, it is possible to test the coefficient of friction in gears. At the beginning of the work is described the issue of operating conditions of satellites in low orbit together with the effects that affect them. Subsequently, suitable polymeric materials are selected, and current publicly available test rigs are described. Based on the research, two conceptual designs are made, one of them is selected and described in detail at the end of the work.
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Biotribology of artificial tears for the treatment of dry eye syndrome
Černohlávek, Mikuláš ; Daniel, Matej (referee) ; Vrbka, Martin (advisor)
This master thesis is a part of the project TAČR TREND, which aim is the development of new ingredient for treatment of dry eye syndrome. Developed ingredient is derivative of hyaluronic acid, which is in this thesis compared with native hyaluronic acids and commercial eye drops. Aim of this thesis is to describe rheological and tribological properties of measured samples in terms of viscosity, mucoadhesivity and coefficient of friction. Coefficient of friction was measured on created tribological model of the eye in pin-on-plate configuration which represents physiologically relevant sliding speeds of blinking. Comparison with native hyaluronic acids and commercial products of eye drops showed, that derivative reaches higher values of viscosity, has mucoahesive properties and has low values of coefficient of friction. Those key parameters show that modification of hyaluronic acid is promising way for drug development for dry eye disease.
|
|
|
The effect of surface condition of artificial joint cup on the friction coefficient
Černohlávek, Mikuláš ; Dočkal, Kryštof (referee) ; Nečas, David (advisor)
This bachelor’s thesis deals with the effect of microtextured surface of an artificial joint cup on a friction coefficient. The primary aim of this thesis was to compare friction coefficients of original and microtextured joint cups. Experimental measurements were made on pendulum hip joint simulator and results were evaluated in Matlab. Four types of femoral heads (CoCrMo, BIOLOX Delta, BIOLOX Forte and oxinium) and three types of lubricants (PBS, model synovial fluid and hyaluronic acid solution) were used during the measurements. The results show, that using PBS and synovial fluid leads to decrease of the coefficient of friction while using modified joint cup. We can assume that microtextured surface of artificial joint cup (separately or in combination with microtextured femoral head) could be a significant benefit for prolonging lifespan of implants.
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