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Computational Modeling of Gear Mesh Engagement Dynamics by MBS Approach
Pykal, Vojtěch ; Řehák, Kamil (referee) ; Prokop, Aleš (advisor)
This master’s thesis is focused on the compilation of a computational modelling of gear mesh engagement dynamics of a spur gear by MBS approach. The user input is the specific geometry of gears, the operating speed, and the load torque. The output are the forces in the gear engagement and the reaction of the forces in the wheel bearings depending on the change in the stiffness of the gear due to the changing number of teeth in the engagement and the change in the axial distance. This model is characterized by a fast and relatively accurate calculation in the time domain. This means that it can react to changes in parameters during simulation such as axial distance, speed, and torque.
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Design of a simulator module for analysis of friction and wear of teeth during cleaning
Snopek, Lukáš ; Streďanská, Alexandra (referee) ; Vrbka, Martin (advisor)
This thesis focuses on the design of a module for the tribological simulator Bruker UMT TriboLab, which will be used in research in the field of analysis of wear of hard dental tissues and filling materials due to tooth cleaning. The aim of this work was the design of experimental conditions, module construction, creation of drawing documentation, production and subsequent implementation of a validation experiment. The conditions of the experiment were determined on the basis of research and to create an optimal design solution, prototypes were continuously produced using the 3D printing method. Finally, two toothbrush fixtures and two dental filling sample fixtures were made based on the drawing documentation. Subsequent assembly of the fixtures and the implementation of the experiment on the tribometer verified their functionality, which makes it possible to declare all the goals successfully met. Now these fixtures will be part of several research tasks in the field of oral biotribology.
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Preliminary aerodynamic analysis of remotely controlled model with jet propulsion
Novák, Ondřej ; Zikmund, Pavel (referee) ; Popela, Robert (advisor)
This bachelor´s thesis deals with aerodynamic analysis of unmanned aircraft and subsequent changes to design of wing, its position and wing-fuselage junction. In this work emphasis is laid on flow separation, its interaction with other flow structures and its influence on aerodynamic properties. The goal of these changes to the aircraft is ensuring sufficient stability and controllability in low as well as high angle of attack flight. AVL, XFLR5 and CFD methods were used in the thesis. In case of inaccuracy of CFD calculation, two backup wing related modifications were prepared.
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Knowledge of selected respondents about oral health
Barcalová, Barbora ; Hanušová, Jaroslava (advisor) ; Váchová, Alena (referee)
Diploma work with the theme Knowledge of selected respondents about oral health consists of a theoretical and a practical part and it deals with level of awareness about oral health by dental hygiene pacients. The main aim of this work is to provide a summary of information about oral health, free from myths and marketing manipulative techniques through a leaflet which is the product of this work. While creating the educational leaflet the author reflects results of a questionnaire survey which is a research tool of the practical part of the diploma thesis. Based on the answers given in the individual questionnaires, the information brochure is primarily directed to refute the most common misconceptions or beliefs of respondents, and at the same time, it was useful for obtaining information about correct oral care in both dental surgeries and e.g. at schools during lessos of health education. The theoretical part of the diploma work is devoted to basic anatomical and histological description of oral cavity, oral health in general, distinction of the terms gingiva, dental plaque or dental calculus. The hinge part is the chapter devoted to dental hygiene, in which the author deals with both profession of a dental hygienist and means of oral cavity care in the setting of the dental hygiene surgery and...
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Structural and Chemical Aspects of Calcium Phosphate Formation in Tooth Enamel
Kallistová, Anna ; Skála, Roman (advisor) ; Frýda, Jiří (referee) ; Oldak, Janet (referee)
Tooth enamel is the hardest and most resistant highly mineralized inorganic component in mammalian bodies that significantly affects both the life quality and expectancy of an indi- vidual. Its specific qualitative properties are given by the biomineralization process responsible for its formation. In this process the mineralization of hydroxyapatite (HAp), the only inor- ganic phase composing the mammalian hard tissues, is controlled by activity of enamel-forming cells ameloblasts and their products. Over the past years, the studies of enamel matrix pro- teins, their structure, composition and function has become the prevalent field of experimental investigation. However, unique enamel qualities, which enable the teeth to withstand high pressure and stress demands, cannot be accurately assessed without the thorough systematical study of its mineral compound. In this thesis, I focus on the crystallographic and compositional characteristics of enamel hydroxyapatite and their influence on the mechanical properties of teeth. Obtained results are discussed in context of developmental and adaptation dynamics of mammalian species. The main aspect of the work is to extend our knowledge about the protein-mediated mineraliza- tion process from the perspective of inorganic compound and its contribution to the...
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Public transport connection of the new Brno Railway station
Bartoň, Daniel ; Pavlíček, Jan (referee) ; Holcner, Petr (advisor)
The diploma thesis deals with the issue of the availability of the new Main Railway Station in Brno, its transfer to other location, modernization or reconstruction and its connection to the public transport system. It focuses in particular on the public transport in Brno affected by the transfer of the railway station and on regional passenger railway transport in the vicinity of Brno. It describes, evaluates and assesses various variants of the transfer of the new railway station in terms of time savings for passengers traveling through the Main Railway Station and their source or destination of travel is in Brno or in the vicinity of Brno. The most suitable appears variant B - the transfer of the station under Petrov.
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The signs of odontogenesis externally to the prospective functional dentition in the experimental model
Fábik, Jaroslav ; Hovořáková, Mária (advisor) ; Buchtová, Marcela (referee)
6 Abstract The development of the mouse tooth primordium is an important model for studying odontogenesis, as well as general organogenesis. The development of the mouse lower incisor is of remarkable interest. The epithelial anlage of the mouse lower incisor is interconnected with the vestibular anlage via the epithelial bridges. According to some authors, the epithelial bridges represent an area, where the transient rudimentary incisor germ appears. From a morphological point of view, the first sign of ongoing epithelial-mesenchymal interactions during early odontogenesis is the thickening of oral epithelium. From a molecular point of view, it is the expression of the Shh, Eda, Edar, Pitx2, Bmp2, Bmp4 and Dlx2 genes. Except for the transcription domain, representing the proper signalling centre of a developing prospective incisor, a transient transcription domain, localized anteriorly and superficially, appears in the odontogenic zone of the epithelium during early development. The anterior transcription domain originates in the area of epithelial bridges, and according to some authors, from an evolutionary point of view, it corresponds with the signalling centre of the rudimentary incisor germ. The aim of this diploma thesis was to compare the temporospatial dynamics of SHH and EDA protein expression in...
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Výživa ve vztahu k zubnímu kazu
Kunická, Kristýna
Dental caries is a health problem of people worldwide. It is a transmissible bacterial disease process caused by acids from bacterial metabolism. The acids are produced, when fermentable carbohydrates in foods or drinks react with bacteria present in the dental plaque on the tooth surface. The acids lead to a loss of calcium and phosphate from the enamel, this process is called demineralisation. Dental caries is a process of many cycles of demineralisation and remineralisation. Demineralisation begins inside the enamel or dentine and can continue until forming dental caries. In this work it is mentioned causes and factors of formation of dental caries such as high number of cariogenic bacteria, quantity and quality of saliva, insufficient application of fluorides, poor oral hygiene and inappropriate nutrition.
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Proliferace a dynamika tkání během vývoje zubů a jim pribuzných patrových lišt
Rothová, Michaela ; Peterková, Renata (advisor) ; Matalová, Eva (referee) ; Černý, Robert (referee)
My PhD thesis has addressed specific questions regarding cell proliferation and tissue dynamics in three key areas of craniofacial development: during suppression and revitalization of tooth buds that develop in the mouse embryonic dentition as rudiments of lost premolars; during dental papilla and follicle formation of the first mouse molar; and during origin of palatal rugae on the mouse hard palate. By evaluation of cell proliferation, we recorded a change in the proliferation pattern along the cheek region of the mandible between less and more advanced embryos at embryonic day 13.5. Thus during the time period, when the development of the large mouse rudimental premolar primordium (R2) is stopped, we showed that the arrest of the rudiment R2 is caused by exhibiting low rate of cell proliferation and high rate of apoptosis. When Sprouty gene signalling is disrupted, the premolar primordium shows rates of proliferation and apoptosis similar to the growing first molar. The R2 subsequently revitalizes and develops into a supernumerary tooth in front of the first molar. Furthermore, we discovered that the dental mesenchyme is very dynamic tissue during bud and cap stages of tooth development and that the dental papilla of the first molar originates only from a restricted region of the dental...
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Early tooth development of Tabby mice
Smrčková, Lucie ; Peterková, Renata (advisor) ; Černý, Robert (referee)
The developing mouse dentition is a very useful tool to study molecular regulation of odontogenesis and also organogenesis. The embryonic mouse dentition comprises developing functional tooth primordia as well as rudimentary tooth primordia. These rudiments arrest their growth during development and either degenerate or become a part of a functional tooth. Mice with gene defects also allow elucidation of a function of genes, their products and signalling pathways. The protein ectodysplasin is essential for development of ectodermal derivatives - skin, hair, glands and teeth. The Tabby mice have a mutation in the Eda gene, which encodes the protein ectodysplasin, and they display a number of dentition anomalies. Early development of the lower jaw dentition in Tabby embryos has been already morphologically described. As a prerequisite for understanding regulatory mechanisms of odontogenesis in Tabby mice, it is also necessary to map the spatiotemporal dynamics of signalling centres that express Shh in both the rudimentary and functional tooth primordia. The aim of this thesis was to compare the signalling centres based on the Shh expression and its spatiotemporal dynamics in the lower jaw of Tabby and WT mouse embryos. Then the Shh data were correlated with known morphological data to clarify the...
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