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Research on the textured journal bearings for engines in automotive
Svoboda, Martin ; Hartl, Martin (referee) ; Omasta, Milan (advisor)
The aim of this thesis is to describe the effect of surface textures of radial journal bearings with polymer coating on friction and damage development using experimental tests. Wear and friction tests of real bearings with different texture geometries and surface materials were performed. It was found that the wear deterioration of the textured aluminum sliding bearing surface and neutral or positive effects on the wear of the textured bearing with polymer coating. The reason for the improvement is the good resistance to high pressures of the polymer coating and the preservation of the texture dimensions throughout the bearing run. The friction test showed an improvement in the frictional properties of the textured surfaces when the amount of lubricant in contact was insufficient. At the same time, a positive effect on tribological properties was demonstrated by reducing the lateral lubricant discharge.
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Preparation and properties of Bioglass based foam materials
Nedbalová, Radka ; Hadraba, Hynek (referee) ; Dlouhý, Ivo (advisor)
The work deals with the preparation and mechanical properties of coated Bioglass® 45S5 based foam materials with open porosity. The samples have been fabricated applying the replication method with use of polyurethane foam. Furthermore, these samples were coated in order to increase the strength characteristics and crack resistance. Polyvinylalcohol and PVA with cellulose microfibrils have been used as coating. Besides microstructural parameters of investigated materials using the SEM images strength characteristics in compression and in tension were also quantified.
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Design of polymer coating sprayer
Meluzín, Ondřej ; Repka, Martin (referee) ; Šperka, Petr (advisor)
This master’s thesis is aimed on design of polymer coating machine that sprays polymer sliding coatings onto surfaces of crankshaft journal bearings used in car engines. At the beginning of this master’s thesis, basic overview of crankshaft bearings design and materials that are used for sliding coatings is given. Then suitable manufacturing technologies for different materials of coatings are described. After describing basic principles of coating technologies and how crankshaft bearings work, main components used for design of the spraying machine are introduced. Three prototypes of the machine are created in virtual environment to verify ergonomics of control and to fulfill safety requirements. In main part of the thesis, description of all parts and subassemblies, such as frame, spraying circuit, pneumatic regulators and safety features is given. Also functions of all parts of the machine are explained in details. Moreover system for handling and manipulation with coated bearings during all necessary technological operations was created. In addition functionality of the machine was verified and checked by spraying of polymer coating on testing samples and crankshaft bearings.
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Research on the textured journal bearings for engines in automotive
Svoboda, Martin ; Hartl, Martin (referee) ; Omasta, Milan (advisor)
The aim of this thesis is to describe the effect of surface textures of radial journal bearings with polymer coating on friction and damage development using experimental tests. Wear and friction tests of real bearings with different texture geometries and surface materials were performed. It was found that the wear deterioration of the textured aluminum sliding bearing surface and neutral or positive effects on the wear of the textured bearing with polymer coating. The reason for the improvement is the good resistance to high pressures of the polymer coating and the preservation of the texture dimensions throughout the bearing run. The friction test showed an improvement in the frictional properties of the textured surfaces when the amount of lubricant in contact was insufficient. At the same time, a positive effect on tribological properties was demonstrated by reducing the lateral lubricant discharge.
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Targeted biocompatible nanoparticles for therapy and cancer diagnostics.
Neburková, Jitka ; Cígler, Petr (advisor) ; Benson, Veronika (referee) ; Schirhagl, Romana (referee)
Nanoparticles (NPs) have considerable potential in targeted medicine. NPs can merge various functions and serve as labels for imaging or as nanocarriers in therapy. Modification of NPs with targeting ligands can lead to highly specific interactions with targeted cancer cells. However, the efficacy of targeting depends on the ratio between specific and non-specific interactions of a NP with the cell. Non-specific interactions of NPs are unrelated to targeted receptors and need to be eliminated in order to decrease background noise during imaging and adverse effect of drugs on healthy tissues. In this thesis, surface modifications of NPs were explored mainly on biocompatible carbon NPs called nanodiamonds (NDs), which have exceptional fluorescent properties such as long fluorescence lifetime, no photobleaching and photoblinking and sensitivity of their fluorescence to electric and magnetic field. Main issues addressed in this thesis are low colloidal stability of NDs in buffers and media, their non-specific interactions with proteins and cells and limited approaches for ND surface modifications. These issues were solved by coating NDs with a layer of biocompatible, hydrophilic, and electroneutral poly(ethylene glycol) or poly[N-(2- hydroxypropyl) methacrylamide] polymers. Optimized polymer coating...
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Targeted biocompatible nanoparticles for therapy and cancer diagnostics.
Neburková, Jitka
Nanoparticles (NPs) have considerable potential in targeted medicine. NPs can merge various functions and serve as labels for imaging or as nanocarriers in therapy. Modification of NPs with targeting ligands can lead to highly specific interactions with targeted cancer cells. However, the efficacy of targeting depends on the ratio between specific and non-specific interactions of a NP with the cell. Non-specific interactions of NPs are unrelated to targeted receptors and need to be eliminated in order to decrease background noise during imaging and adverse effect of drugs on healthy tissues. In this thesis, surface modifications of NPs were explored mainly on biocompatible carbon NPs called nanodiamonds (NDs), which have exceptional fluorescent properties such as long fluorescence lifetime, no photobleaching and photoblinking and sensitivity of their fluorescence to electric and magnetic field. Main issues addressed in this thesis are low colloidal stability of NDs in buffers and media, their non-specific interactions with proteins and cells and limited approaches for ND surface modifications. These issues were solved by coating NDs with a layer of biocompatible, hydrophilic, and electroneutral poly(ethylene glycol) or poly[N-(2- hydroxypropyl) methacrylamide] polymers. Optimized polymer coating...
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Targeted biocompatible nanoparticles for therapy and cancer diagnostics.
Neburková, Jitka
Nanoparticles (NPs) have considerable potential in targeted medicine. NPs can merge various functions and serve as labels for imaging or as nanocarriers in therapy. Modification of NPs with targeting ligands can lead to highly specific interactions with targeted cancer cells. However, the efficacy of targeting depends on the ratio between specific and non-specific interactions of a NP with the cell. Non-specific interactions of NPs are unrelated to targeted receptors and need to be eliminated in order to decrease background noise during imaging and adverse effect of drugs on healthy tissues. In this thesis, surface modifications of NPs were explored mainly on biocompatible carbon NPs called nanodiamonds (NDs), which have exceptional fluorescent properties such as long fluorescence lifetime, no photobleaching and photoblinking and sensitivity of their fluorescence to electric and magnetic field. Main issues addressed in this thesis are low colloidal stability of NDs in buffers and media, their non-specific interactions with proteins and cells and limited approaches for ND surface modifications. These issues were solved by coating NDs with a layer of biocompatible, hydrophilic, and electroneutral poly(ethylene glycol) or poly[N-(2- hydroxypropyl) methacrylamide] polymers. Optimized polymer coating...
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Targeted biocompatible nanoparticles for therapy and cancer diagnostics.
Neburková, Jitka ; Cígler, Petr (advisor) ; Benson, Veronika (referee) ; Schirhagl, Romana (referee)
Nanoparticles (NPs) have considerable potential in targeted medicine. NPs can merge various functions and serve as labels for imaging or as nanocarriers in therapy. Modification of NPs with targeting ligands can lead to highly specific interactions with targeted cancer cells. However, the efficacy of targeting depends on the ratio between specific and non-specific interactions of a NP with the cell. Non-specific interactions of NPs are unrelated to targeted receptors and need to be eliminated in order to decrease background noise during imaging and adverse effect of drugs on healthy tissues. In this thesis, surface modifications of NPs were explored mainly on biocompatible carbon NPs called nanodiamonds (NDs), which have exceptional fluorescent properties such as long fluorescence lifetime, no photobleaching and photoblinking and sensitivity of their fluorescence to electric and magnetic field. Main issues addressed in this thesis are low colloidal stability of NDs in buffers and media, their non-specific interactions with proteins and cells and limited approaches for ND surface modifications. These issues were solved by coating NDs with a layer of biocompatible, hydrophilic, and electroneutral poly(ethylene glycol) or poly[N-(2- hydroxypropyl) methacrylamide] polymers. Optimized polymer coating...
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Design of polymer coating sprayer
Meluzín, Ondřej ; Repka, Martin (referee) ; Šperka, Petr (advisor)
This master’s thesis is aimed on design of polymer coating machine that sprays polymer sliding coatings onto surfaces of crankshaft journal bearings used in car engines. At the beginning of this master’s thesis, basic overview of crankshaft bearings design and materials that are used for sliding coatings is given. Then suitable manufacturing technologies for different materials of coatings are described. After describing basic principles of coating technologies and how crankshaft bearings work, main components used for design of the spraying machine are introduced. Three prototypes of the machine are created in virtual environment to verify ergonomics of control and to fulfill safety requirements. In main part of the thesis, description of all parts and subassemblies, such as frame, spraying circuit, pneumatic regulators and safety features is given. Also functions of all parts of the machine are explained in details. Moreover system for handling and manipulation with coated bearings during all necessary technological operations was created. In addition functionality of the machine was verified and checked by spraying of polymer coating on testing samples and crankshaft bearings.
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Preparation and properties of Bioglass based foam materials
Nedbalová, Radka ; Hadraba, Hynek (referee) ; Dlouhý, Ivo (advisor)
The work deals with the preparation and mechanical properties of coated Bioglass® 45S5 based foam materials with open porosity. The samples have been fabricated applying the replication method with use of polyurethane foam. Furthermore, these samples were coated in order to increase the strength characteristics and crack resistance. Polyvinylalcohol and PVA with cellulose microfibrils have been used as coating. Besides microstructural parameters of investigated materials using the SEM images strength characteristics in compression and in tension were also quantified.
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