|
|
Studies of tokamak edge plasma and its interaction with the first wall
Komm, Michael ; Kudrna, Pavel (advisor) ; Hrach, Rudolf (referee) ; Svoboda, Vojtěch (referee)
Title: Studies of tokamak edge plasma and its interaction with the first wall Author: Michael Komm Department: Department of Surface and Plasma Science Thesis director: doc. Mgr. Pavel Kudrna, Dr. KFPP Thesis supervisor: Dr. Renaud Dejarnac, IPP CAS CR Abstract: This work presents results of simulations of nuclear fusion related problems, using both 2D PIC code (SPICE2) and full 3D code (SPICE3). The simulations allowed us to predict particle and heat loads coming from plasma onto the divertor tiles, which is a key problem for the next-step de- vices. The results of simulations contributed to the research of fuel retention in the gaps between divertor tiles. We we also able to explain the behaviour of the Katsumata probe and verify the validity of its measurements. Keywords: Tokamak, PIC, divertor, tritium, Katsumata
|
|
|
Cleanthes' hymn to Zeus in its archaic Greek context
Svoboda, Vojtěch ; Jirsa, Jakub (referee) ; Kratochvíl, Zdeněk (advisor)
In its general part, this study tracks archaic motives in the Stoic (and at the first place Kleanthes') cosmology, in particular in respect of his conception of tonos. It concerns the relationship between the Stoics and the pre-Socratic philosophers as such, namely their attitude to Heraclitus. The study examines the transition of the text of Heraclitus' book to the Stoa and the role of different interpretations of Heraclitus as to the Stoic reception. In its special part, I concentrate on the place of the Hymn to Zeus in the hymnal tradition, especially on the influence of Aeschylus who carries many archaic elements. The final passage contains, hopefully, a complete list of parallels between the extant fragments of Heraclitus and the Hymn of Cleanthes.
|
|
|
Anomalous Ion Diffusion in Models of Turbulent Edge Tokamak Plasma
Papřok, Richard ; Krlín, Ladislav (advisor) ; Svoboda, Vojtěch (referee) ; Langer, Jiří (referee)
Enhanced particle and energy transport from edge plasma is observed and may cause a problem for a future operation of a thermonuclear reactor. Plasma edge turbulence presents a complex problem which is not fully theoretically understood. We chose a simple, mathematically simply described potential, which represents first approximation of the realistic one. Resulting dynamics led, for certain class of parameters, to a phenomenon known as Lévy walks, which is the cause of an anomalous enhanced diffusion. It is shown that for typical tokamak's parameters it is in this class and therefore it can be a cause of an anomalous transport in plasma.
|
|
| |
|
|
Characteristics of rainfall in observed data and regional climate model simulations
Svoboda, Vojtěch ; Pech, Pavel (advisor) ; Josef, Josef (referee)
Precipitation in the form of heavy rainfall events is of significant societal concern, not only due to the potential for more frequent flash floods, after evidence of changes in rainfall characteristics has recently strengthened. Despite the importance of individual rainfall events with respect to many hydrological applications, only a few studies dealt with characteristics of individual rainfall events (in contrast with the other daily/sub-daily indices of rainfall depths/intensities). Dissertation thesis presents a comprehensive analysis of heavy rainfall event characteristics for the Czech Republic derived from observed data and large ensemble of regional climate model (RCM) simulations. In addition, spatial correlation structure of observed rainfall data at a mesoscale region of north-eastern Bohemia was analysed. Since an RCM grid box represents a spatial average rather than a point measurement, the effects from areal averaging of rainfall data on characteristics of events were investigated considering the observed data. Characteristics of rainfall events were evaluated according to several indices against the at-site and area-averaged observed data for the control period 1981-2000. The changes of rainfall event characteristics were assesed over two scenario periods (2020-2049 and 2070-2099) with respect to control period. We analysed also relations between changes in simulated rainfall event characteristics and changes in radiative forcing and temperature.
|
|
| |
|
|
Jean - Luis Barrault
Svoboda, Vojtěch ; PETIŠKOVÁ, Ladislava (advisor) ; HYVNAR, Jan (referee)
This work discusses the life and work of Jean-Louis Barrault, one of the most significant french theatre artist. Barrault is known as an excellent actor, mime, directer and theatre theorist. His contribution to the development of Europian theatre in the last century is very important, especially to mimic theatre styles. The thesis shows Barraults personality and art with a focus on his contribution to pantomime. Another task is to explore influence of different personalities on the artistic development of Jean-Louis Barrault.
|
|
|
The Influence of Dynamic Stretching to the Immediate Enforcement
SVOBODA, Vojtěch
The work is focused on the evaluation of the impact of two types of stretching on subsequent performance. With regard to the content can be divided into practical and theoretical. A practical part brings relevant knowledge to solve problems. Attention is given to the anatomy of the muscle fiber, the physiology of muscle contraction and muscle connections with the central nervous system. The study also describes the proprioceptive function of muscles, the anatomical dimensions and principles of operation. In connection with the internal control possibilities stretching the muscles are in the theoretical part also describes the reflexes at the level of the muscle fiber. General principles of stretching can be found in this section too. The following is a detailed resolution types of stretching and their implementation, advantages and disadvantages. At the end of the theoretical part describes general contraindications stretching and hypermobility as one of the risk factors. The second part belonged to practical research. The research aims to answer the question: "Which type of stretching before exercise has a better effect on the actual performance?" For this purpose we selected eight active athletes. After showing of concrete stretching workouts were tested person familiar with the disciplines in which the effect of stretching measured. It was a 40 yard sprint, a specific form of the shuttle run, jump from a place in the distance and the implementation of push-ups without stopping to find the maximum number of times. These disciplines have been always performed after the application of one type of stretching, with a minimum range of measurement was determined at 24 hours, for reasons of objectivity research. Overall, each activity was measured four times - twice after the static and twice after the dynamic stretching. Research records the individual variations in the measured values after the static and dynamic stretching in all tests. For better clarity, the deviations from the established arithmetic averages referring to the average positive and negative deviations. The resulting values are then captured in tables, graphically and verbally explained. All the four measurements showed analogous results. In the first three disciplines is a better determination of the dynamic type of stretching due to the relatively higher performance of individual activities. For Sprint and the shuttle run times were recorded less necessary to overcome the distance. At the same time was also significantly better in negative average deviation of the measured times after dynamic stretching. The last tested motion became workout pushups without rest for the maximum number of repetitions achieved. Based on this research it is not possible to determine the appropriate method of preparation for discipline. Implementation of push ups assigns power-endurance nature. Due to the relatively clear results for the other, short-term activities associated with the maximum of performance, it seems clear that the type of stretching manifests a greater impact with this type of load compared to strength-endurance exercise in the form of push-ups. Chapter titled "Discussion" is again divided into two parts. In the first analysis is made of the results and conclusions with regard to possible opposition view on objectivity of measurement. Research is generally considered as the objective and the results are accorded legitimacy. In the second part of the discussion are the conclusions obtained subject to comparison with other international studies that have looked at the impact of these types of stretching at the same or a similar discipline. Given the above facts and research itself can be considered for answering the research question. Short-term disciplines carried out with maximum intensity can be demonstrated dynamic stretching before the actual performance for better compared to static stretching.
|
|
| |
|
| |
guest ::
RSS feed.