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Friction and lubrication of total hip replacement produced by 3D metal printing technology
Uhrová, Simona ; Horák, Zdeněk (referee) ; Vrbka, Martin (advisor)
This thesis investigates the tribological properties of total hip replacements manufactured by both traditional and additive technologies. The primary objective is to assess the impact of different manufacturing methods on friction and lubrication at the contact between the joint head and the acetabular cup. Techniques such as a pendulum joint simulator and optical methods are utilized to analyse the lubricant film formation and friction coefficient. The findings indicate that additively manufactured implants can potentially offer comparable or superior tribological properties compared to traditional methods, potentially leading to enhanced longevity and functionality of the implants. However, the need for appropriate surface treatment and further research into wear to ensure extended life and improved implant functionality is emphasised.
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Friction of Titanium Surfaces in Implantology
Heto, Matyáš ; Odehnal, Lukáš (referee) ; Ranuša, Matúš (advisor)
This bachelor thesis focuses on the frictional properties and wear resistance of Ti6Al4V alloy. This alloy is suitable for use in orthopaedic implants such as the first metatarsophalangeal (MTP) joint in the big toe. The aim is to investigate different surface treatment methods that can reduce friction and wear of this material. The effect of applying DLC coatings and creating microtextures or microstructures on the surface is described. Metal on metal pair tests have been carried out using profilometer and tribometer in pin on plate configuration. The results show a noticeably higher coefficient of friction for the Ti6Al4V alloy than for the compared CoCrMo alloy. DLC coating significantly helped in reducing the friction and wear of Ti6Al4V. This cannot be said for the two microstructures tested, which did not have a significant effect on the observed tribological properties. The results indicate the importance of surface treatment of Ti6Al4V alloy for use in implants.
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Optimization Of Selected Proposed ČSN Elements For Road Design
Kokeš, Ondřej ; Čepil, Jiří (referee) ; Radimský, Michal (advisor)
Diploma thesis describes and researches some proposed ČSN 73 6101 elements for road design and their subsequent comparison with Norma de Traçado that is main law for road design in Portugal. In practical part, the speed of vehicles during moving on direction curves is researched and subsequently coherence of theoretical assumptions with real speeds is compared. The main aim of this work is to verify the assumption that design speed does not correspond to the real speed that drivers move on road structures.
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Pavement skid resistance and Skid Resistance Index
Nekulová, Pavla ; Šachlová, Zora (referee) ; Kudrna, Jan (advisor)
This diploma thesis deals with the relation between the longitudinal friction coefficient dependence on measuring speed and the value of road surface macrotexture MPD. Results of longitudinal friction coefficient and value of MPD measurement on 73 sections are included in this thesis. The results were compared by regression analysis and its outcome was used for determination of formula that enable calculation of longitudinal friction coefficient for any operating speed when longitudinal friction coefficient for 60 km/h and value of macrotexture are known. The evaluation scale for skid resistance index (SRI) was also determined in this thesis. It could be used for evaluation of skid resistance independently of the type of device used for friction coefficient measurement.
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Dependance of pavement surface skid resistance on aggregate polishing and traffic loading
Dašková, Jaroslava ; Čelko,, Ján (referee) ; Šachl,, Jindřich (referee) ; Vojtěšek, Antonín (referee) ; Kudrna, Jan (advisor)
Road safety is a complex problem. It is influenced mainly by the driver, the vehicle and the road surface. This thesis is focused on the road surface properties and especially skid resistance that directly affect the braking distance and keeping the vehicle in the horizontal curves and thus traffic accidents. The thesis deals with the durability of pavement surface skid resistance, the type of pavement layers and aggregate polishing used in wearing course. The aim of this thesis was to develop the methodology for improvement of road surfaces skid resistance durability and implementation of functional test for their assessment.
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Comparison of frictional properties of cosmetic massage products
Dohnal, Petr ; Čípek, Pavel (referee) ; Vrbka, Martin (advisor)
This bachelor’s thesis examines tribological properties of massage products (creams and oils). Its aim is to create a comparison of the selected products. Tribometer in the pin-on-plate configuration was used for the experiment because of its ability to simulate the process of rubbing the product on the skin. Cowhide was used as a model of human skin. The attributes of products were compared based on the characteristics of the coefficient of friction during the measurements. Through the experiments a suitable parameter was found for easy comparison of the product's durability. According to the results the best oil was selected in terms of durability and lubrication. The thesis could be used as a basis for creating a standardised method for evaluation and selection of products suitable for massage purposes.
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Friction of materials for optomechanical parts
Mořický, Ondřej ; Košťál, David (referee) ; Šperka, Petr (advisor)
This bachelor thesis deals with friction between materials used in the construction of optomechanical assemblies. The aim of the thesis is to compare coefficient of friction for different combinations of surfaces, different roughness, and different surface treatments. Experimental measurement was carried out on a tribometer using the pin-on-plate method under the dry friction conditions. Graphs of the development of coefficient of friction over time and a table to compare individual combinations were compiled from the results of the measurement. It includes an analysis of surfaces using optical profilometry before and after the tests.
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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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