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Dynamic behavior od rotor dynamics system vibrating in a liquid
Kučera, Martin ; Pohanka, Lukáš (referee) ; Malenovský, Eduard (advisor)
This thesis deals with dynamic behavior of rotor dynamics system vibrating in a liquid. Work is factually oriented on influence of the liquid to natural frequences of rotor of vortex turbine. There is described the creation of geometric and computational model of the system and the results of natural frequences and damping in dependence on environment are presen-ted. There are compared variations in natural frequences of the rotor system, which are caused of the interaction of the various level of the water environment. The step of integration are tested and compared for choise solving method. Problem is solved by computational simulation in commercial software ANSYS 11.0 There is used software tools Multiphysics/FSI.
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Plasma spraying from liquids: plasma liquid interaction and coating build up
Tesař, Tomáš ; Mušálek, Radek ; Medřický, Jan ; Lukáč, František
Plasma spraying from liquid feedstocks is a rapidly developing field of thermal spraying since the coatings prepared from liquids exhibit some unique features, such as high hardness, thermal shock resistance or low thermal and electric conductivity. The key factor influencing the final coating character and properties is the input material which may be in the form of a suspension or a solution. Parameters of the selected suspension (solids concentration, viscosity, surface tension, chemical composition, etc.) or solution (concentration, etc.) determine its interaction with the plasma jet which strongly influences the coating buildup. This proceeding introduces the problematics of the interaction between the liquid feedstock material with the plasma jet and presents the way of evaluation of the coating buildup.
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Children attachment to adult care providers in children homes - analysis of conditions and possibilities
Esterková, Manuela ; Matoušek, Oldřich (advisor) ; Pazlarová, Hana (referee)
The thesis tries to find the answer to the basic question: "What are the possible ways to strengthen attachment between children at the age from 9 to 18 months and their caregivers at the facilities of institutional care, nurses in particular?" The work also aspires to map the external conditions influencing formation of the attachment. In order to explain the topic, some theoretical findings of developmental psychology, attachment theory and information about the system of institutional care in the Czech Republic have been presented here. The answers concerning the strongest factors of attachment behavior and different attachment of one child to various caregivers and vice versa were being sought with the help of the method of an involved observation of the interaction child-caregiver during specific activities of feeding and bathing. Pieces of information about external influences of the attachment behavior and the possibilities to nurture it were being gathered by the method of semi-structural interview with the caregivers and the directors of the visited institutions. The activities of feeding and bathing, which were being observed, have been split into individual elements of attachment behavior (on the side of a child: visual attention, vocal reactions, smile and stretching arms towards the caregiver;...
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Microbiota of the digestive tract of bees and related insect and the influencing facftors
Hroncová, Zuzana ; Havlík, Jaroslav (advisor) ; Kalous, Lukáš (referee)
This thesis consists of six research chapters, out of which, five have already been published in research journals, 1 is in the process of submission and the last chapter presents original unpublished confidential data in the process of manuscript preparation.
The research presented in this thesis concerns the complex mechanisms of bees and wasps immune system focused on microbiota as component of immunity. As shown in the introduction, highly social and managed species of bees like honey bees and bumble bees, play key roles in natural and agricultural ecosystems worldwide. Recent losses of bees have been attributed to pesticide exposure, poor nutrition, increased parasite loads and habitat degradation. Over the past several years, governments, beekeepers, and the general public worldwide have become concerned by increased losses of honey bee colonies, calling for more research on how to keep colonies healthy. Our main aim was to explore the complex mechanisms of bees and related species gut bacterial populations, their links to insect immunity and investigate the opportunities for an intervention. Part of our aim was to characterise the bumble bee and wasp gut microbiota using 16S RNA sequencing in a search for potentially novel bacterial species.
We have tried to explain how microbiome interacts with the host and showed that major members of these communities appear to benefit the host. The simple gut communities of social bees present ideal model systems to investigate the underlying evolutionary and genetic processes of such interactions. Information based on our results may help in the design of proper probiotic supplementation strategies with respect to physiological conditions in the honey bee gut.
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Freezing technology of bull sperm in relation to its survivability and fertilization ability
Doležalová, Martina ; Stádník, Luděk (advisor) ; Jiří, Jiří (referee)
The aim of optimalization the insemination doses production is to provide the highest fertilization ability of spermatozoa during the demanding proces of processing fresh semen and its subsequent cryopreservation. Temperature changes causes spermatozoa damage during the cooling and freezing. Spermatozoa is exposed to cold shock and many others limiting factors, which leads to cell death and therefore to decline of fertilization ability of thawed insemination doses. For increasing spermatozoa resistance, exactly the plasma membrane resistance against cold shock was fraction of egg yolk LDL cholesterol (low density lipoprotein) at various concentrations into the comercially produced diluents added. It is believed that LDL acts possitively to plasma membrane and helps to maintain the fertilization ability of spermatozoa after thawing. Following step in the proces of insemination doses production is slow cooling of diluted semen and equilibration, when the straws are store at cooling box for 30 minutes to 240 hours. This period is necessary to penetrate of certain diluent components into the spermatazoa also maintain the balance between their intracellular and extracellular concentration. Also important is subsequent freezing temperature gradient of insemination doses. The most suitable freezing method is based on computer controlled temperature decline in freezing chamber which allows the precise control of ice crystals formation that could tear and kill the cell.
During 2012 to 2016 was repeatedly collected semen from the group of breeding bulls (n = 27, Holstein and Czech Fleckvieh breed) at AI centre. Semen which fulfill the standard entrance conditions in first step was evenly into several parts divided. For dilution the three types of comercially diluents AndroMed, Bioxcell and Triladyl with and without LDL addition were used. Into the diluents AndroMed and Bioxcell the concentration of LDL 4 %, 6 % and 8% into the dilent Triladyl 6 %, 8 % and 10 % was added. Diluted semen was filled into the glass capillares with volume 0,1 ml and temperature +4 °C. Subsequently the sample was placed to cold bath (0°C) for 10 minutes. Then the volume of capillare with physiological solution (37 °C) was mixed and for next 120 minutes was incubate. The effect of cold shock to proportion of live spermatozoa was evaluated by using Eosin and Nigrosine staining technique during heat test of spermatozoa survivability after spermatozoa heating and after 120 minutes of incubation.
The more suitable semen diluents which provide the higher spermatozoa resistance against cold shock were AndroMed and Bioxcell. Together the possitive effect of LDL addition into the diluents to lower decrease of proportion of live spermatozoa during heat test was found (P<0.05). The most suitable LDL concentration which had a favorable influence at spermatozoa resistance against cold shock was 6 % in diluent Bioxcell. Values of the proportion of live sperm were higher at the beginning of the heat test (+1.31% to + 3.2%) and after 120 minute incubation (+5.82% to +8.41%) compared to other diluents with and without addition of LDL.
In the next step the process of equilibration was optimized, is an important part of insemination doses production. The effect of the length of equilibration for subsequent fertilization ability of spermatozoa was evaluated using spermatozoa motility based of CASA and proportion of live spermatozoa after thawing and during heat survival test lasting 120 minutes (37 ° C). Suitable semen was diluted by comercially used diluent AndroMed based on soya lecithin, filled into the straws (0.25 ml), cooled and equilibrated in cooling box for 30, 120 and 240 minutes and freezed in programmable freezing box applying four types of freezing curves differing in temperature rate decline. There was used standard and by producer recommended 3. phase freezing curve, then 2. phase freezing curve, and 3. phase freezing curve with slower as well as rapid decline of temperature rate in freezing chamber, compared with standard freezing curve. The highest spermatozoa motility was found using 240 minutes of equilibration by +2.72% and +4.58% compared to other lengths of equilibration (P <0.05 to 0.01). The highest proportion of live spermatozoa was found using 120 minutes of equilibration (+6.87 % and +8.68 %). The highest average spermatozoa motility during heat test after thawing was achieved by using 2. phase freezing curve (from +2.97% to +10.37%, P <0.05), also in the proportion of live spermatozoa (from + 4.37% to +8.82%, P <0.01). When evaluating interaction between the length of equilibration and freezing curve (standard 3. phase and 2 . phase freezing curve), the highest average spermatozoa motility and proportion of live spermatozoa using 240 minutes of equilibration by both freezing curves was reached, there was no statistically significant differences. As well as, in all evaluated parts of this study the individual differences between ejaculate of bulls and within semen from one bull (P <0.05) as secondary effect were found.
To maintain good fertilization ability of semen during cryopreservation is necessary to increase the spermatozoa resistance against cold shock using addition of correct concentration of LDL into the commercially used diluents AndroMed and Bioxcell. Subsequently the fertilization ability of insemination dose is influenced by cooling, the length of equilibration and freezing. The length of equilibration 120 minutes and more as well as gentle way of freezing according to freezing curve, which ensures a gradual decrease of temperature in freezing chamber provided the higher average spermatozoa motility and proportion of live spermatozoa.
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The collection of published articles
DVOŘÁK, Petr
The aim of the collection of published articles is to define the requisite social skills of the English language teacher as a part of his/her professional competence, in the context of communicative language teaching in classroom interactions between English teachers and adolescent pupils. The theoretical preliminaries of the research whose findings are presented in the articles are the functional communicative approach to language and communicative language teaching. The attention is paid to the processes of interaction, communication and classroom discourse at school with an emphasis on foreign language teaching. We try to specify social skills of the English teacher and define social-skill aspects of foreign language educational interactions. The findings of the research presented in the articles concern mainly the educational style of English teachers and English teacher's behaviour in particular classroom interactions. The research is also focused on selected social-skill aspects of classroom discourse within communicative language teaching, specifically, pupils' and teachers' initiations of communication, questions, and the distribution of communication opportunities.
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Coulomb interactions in electron beams
Jánský, Pavel
The paper describes numerical calculations of thermionic electron gun of an electron-beam welding machine and optimization of its electron optical system. It describes new method used in program EOD for determination of space-charge effect on emitted current and on electron trajectories in the gun.
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Thin films modification by focussed ion beam.
Faltýnek, Petr ; Čechal, Jan (advisor)
The purpouse of the master's thesis is study problematic of focused ion beams and their material influence. In this thesis are described interactions in the sample after impact of ion beam, use and applications of FIB systems. Second part of thesis are simulations of ion influence on different kinds of materials by the help of SRIM program.
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Maurice Drury and Ludwig Wittgenstein
Schmoranz, Tereza ; Hill, James (referee) ; Peregrin, Jaroslav (advisor)
The aim oj this essay is to "discover" for the Czech scholarly public a work of considerable importance for both the field of philosophy and the domain established on the borderline between philosophy and psychiatry. In a critical analysis oj the application ofWi ttgenstein 's philosophical method to some of the delicate problems of psychiatry, this essay intends to contribute to a deeper insight into the relationship between these fields and also to facilitate their interaction.
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