|
|
Machinery used for drop forging
Vondráček, Petr ; Řiháček, Jan (referee) ; Podaný, Kamil (advisor)
The bachelor thesis contains distribution and overview of the machines used in the proces of die forging and their modern innovation. For individual mechanism is described principle, structural arrangements and advantages or disadvantages, or the example of used machine for which is described his charaterisctic, basic parameters and productions possibilities with example of made forged.
|
|
|
Family house in Čechočovice
Vondráček, Petr ; Kervitcer, Marek (referee) ; Sobotka, Jindřich (advisor)
This bachelor thesis deals with the design of a family house in Čechočovice in the district of Třebíč. The family house is designed as a two-storey, partially basement building, roofed by two ramps. The project was created for the purpose of designing a permanent home for a 5-member family with the possibility of two garage parking spaces. The perimeter walls in the basement are made of ceramic blocks of the Porotherm system and insulated with extruded polystyrene. The perimeter walls of the above floors are made of Porotherm brick blocks with embedded mineral insulation. The ceiling structure is designed from the Porotherm system. The plot is slightly inclined. Part of the proposal is thermal engineering assessment, fire safety solutions and assessment in terms of acoustics and daylight. The thesis contains a drawings and technical documentation and it is composed as an implementation project.
|
|
|
Multifunctional House Brno - Holásky
Vondráček, Petr ; Procházka, Jiří (referee) ; Sobotka, Jindřich (advisor)
This diploma thesis deals with design of new building multifunctional house in southeastern outskirts of Brno in urban district Holásky. The three-storey building combines purpose of permanent housing, stomatology center and pharmacy. Business premises and technical facilities are located on the ground floor. Overall twelve dwelling units with layout design as one-bedroom flat and two-bedroom flat are placed on above-ground floors. Designed building has rectangular trapezoid shape and copies triangle shape of flat building plot. Parking spaces are perpendicular to adjacent access road. External walls are made of 500 mm thick Porotherm hollow clay blocks with inserted mineral insulation. Ceiling structure is designed as reinforced concrete slab, which is divided into set of smaller two way slabs. Building is roofed with flat roof, on it are placed solar collectors used for water heating and reducing operating costs. Effective management of rainwater which is collected and reused helps decrease environmental impact of building. Total energy consumption of the building is reduced by building compactness. Thesis contains project documentation for the construction.
|
|
|
Clinical and elektrophysiology longitudinal study of children with hereditary neurophathy Charlot-Marie-Tooth type 1A
Haberlová, Jana ; Seeman, Pavel (advisor) ; Syka, Josef (referee) ; Ambler, Zdeněk (referee) ; Vondráček, Petr (referee)
Hereditary peripheral neuropathy, known asCharcot Marie Tooth disease (CMT) and with an incidence of 1:2500 -1:10 000, is the most common hereditary neuromuscular disorder. Type CMT 1A is the most common form of CMT refering to the group of primary demyelinitateing motor and sensory peripheral neuropathies. CMT phenotype is clinically characterized by chronic slowly progressive distal muscle weakness and atrophy with hypo or areflexia and mild to moderate acral sensory loss. The lower limbs are predominantly affected. The aims of this study were to describe the first and most common signs of CMT1A during the first decade of life, to characterize their progression, and evaluate the sensitivity of CMTNS (Charcot-Marie- Tooth neuropath scale) for CMT1A young children. Sixteen children aged 3 to 10 years with genetically proven CMT 1A were examined. All patients were clinically examined, underwent electrophysiological examination, and were scored by CMTNS. Eight were followed for up to two years. Our data shows that CMT 1A in children under the age of 10 years causes only a mild disability. Initial signs of CMT 1A were difficulty in heel walking (15/16, 93%) and lower limb hypo or areflexia ( 13/16, 81%). The test of heel walking can be easily used as a screening test for hereditary neuropathies in pediatrics....
|
|
|
Multifunctional House Brno - Holásky
Vondráček, Petr ; Procházka, Jiří (referee) ; Sobotka, Jindřich (advisor)
This diploma thesis deals with design of new building multifunctional house in southeastern outskirts of Brno in urban district Holásky. The three-storey building combines purpose of permanent housing, stomatology center and pharmacy. Business premises and technical facilities are located on the ground floor. Overall twelve dwelling units with layout design as one-bedroom flat and two-bedroom flat are placed on above-ground floors. Designed building has rectangular trapezoid shape and copies triangle shape of flat building plot. Parking spaces are perpendicular to adjacent access road. External walls are made of 500 mm thick Porotherm hollow clay blocks with inserted mineral insulation. Ceiling structure is designed as reinforced concrete slab, which is divided into set of smaller two way slabs. Building is roofed with flat roof, on it are placed solar collectors used for water heating and reducing operating costs. Effective management of rainwater which is collected and reused helps decrease environmental impact of building. Total energy consumption of the building is reduced by building compactness. Thesis contains project documentation for the construction.
|
|
|
Plasma Heat Flux to Solid Structures in Tokamaks
Vondráček, Petr ; Horáček, Jan (advisor) ; Gunn, James P. (referee) ; Svoboda, Vojtěch (referee)
Plasma Heat Flux to Solid Structures in Tokamaks Petr Vondráček Energy and particle exhaust is the key issue for future fusion reactors based on magnetic plasma confinement, namely for tokamaks. Good understanding of processes controlling plasma heat fluxes impinging the first wall of tokamaks is of a main concern for fusion research. This doctoral thesis is focused on experimental investigation of plasma heat fluxes in different locations of the COMPASS tokamak. A new infrared thermography system was built for this purpose as a part of this PhD research. There are four main topics studied using the system. First of all, a narrow near-SOL heat flux channel with a very steep radial profile is characterised in HFS limited discharges. It is shown that the near-SOL heat flux decay length is consistent with the drift-based model of the SOL heat transport. Secondly, heat loading of leading edges of misaligned limiters is broadly studied. The optical approximation of the heat flux distribution around a poloidal leading edge is confirmed as a valid approach. Heat loading of a magnetically shadowed side of a toroidal limiter gap is observed experimentally for the first time confirming predictions of particle-in-cell code simulations. Thirdly, localised hot-spots caused by the impact of runaway electrons as well as...
|
|
|
Fluctuations in the scrape-off layer and edge plasma of the COMPASS tokamak
Seidl, Jakub ; Jiráková, Kateřina ; Adámek, Jiří ; Grover, Ondřej ; Horáček, Jan ; Hron, Martin ; Vondráček, Petr
We have identified two distinct types of turbulent fluctuations in COMPASS plasmas, the high-frequency edge oscillations and low-frequency SOL blobs. The transition region is localized in the near SOL, where both types spatially overlap and interact and the radial particle transport gradually transfers from high to low frequencies. Even though skewness of isat fluctuations is positive even inside LCFS, distinguishable Gamma-distributed PDF, formed by the low-frequency fluctuations, arises in the near SOL. This supports, together with turbulence spreading rate being positive in the near SOL but negative in the edge, the picture presented in [3] that most of the fluctuations that form a positive skewness in the edge region disappear around LCFS and new blobs are formed in the near SOL. Further, we cannot confirm the assumption that the blobs are generated randomly according to a Poisson process. Oscillations of all measured quantities, incl. radial particle flux, in the near SOL are peaked around ∼13 kHz. This seems to correspond to a poloidally rotating structure with a rather large poloidal wave-length ∼ 15 − 20 cm, that at least partly modulates blob generation. Nevertheless, we note that time separation of blobs becomes more random further in the SOL, possibly due to differences in their individual propagation. These observations hold for diverted plasmas, but the situation may be different in limited low-elongation plasmas where the radius of zero skewness was observed to be shifted significantly (several cm) inwards, compared to diverted configuration, and Gamma-like PDF is detected even inside the LCFS. Study of these plasmas is ongoing.
|
|
|
Fluctuations in the scrape-off layer and edge plasma of the COMPASS tokamak
Seidl, Jakub ; Jiráková, Kateřina ; Adámek, Jiří ; Grover, Ondřej ; Horáček, Jan ; Hron, Martin ; Vondráček, Petr
In this work we study properties of turbulent structures in the scrape-off layer (SOL) and edge plasma of the COMPASS tokamak. Two distinct types of coherent oscillations are observed: a) broadband high frequency branch rotating in the electron diamagnetic direction, appearing mainly in the confined region but protruding also to the SOL b) low-frequency blobs rotating in an opposite poloidal direction, formed in the vicinity of the radius of zero electric field. The transition region is localized in the near SOL, where both types spatially overlap and interact and the radial particle transport gradually transfers from high to low frequencies. Even though skewness of fluctuations of the ion saturation current is positive even inside LCFS, distinguishable Gamma-distributed PDF, formed by the low-frequency fluctuations, arises in the near SOL and most of the fluctuations that form a positive skewness in the edge region disappear around LCFS.
|
|
|
RE beam generation in MGI disruptions on COMPASS.
Ficker, Ondřej ; Mlynář, Jan ; Macúšová, Eva ; Vlainić, M. ; Weinzettl, Vladimír ; Urban, Jakub ; Čeřovský, Jaroslav ; Farník, Michal ; Markovič, Tomáš ; Papřok, Richard ; Vondráček, Petr ; Imríšek, Martin ; Tomeš, Matěj ; Havlíček, Josef ; Varju, Jozef ; Varavin, Mykyta ; Bogár, Ondrej ; Havránek, Aleš ; Gospodarczyk, M. ; Rabinski, M. ; Jakubowski, M. ; Malinovski, K. ; Zebrowski, J. ; Plyusnin, V. ; Papp, G. ; Pánek, Radomír ; Hron, Martin
In the experiments with the massive gas injection (MGI) triggered disruptions in the COMPASS tokamak, post-disruptive runaway electron (RE) beams are generated occasionally. In this contribution, a relatively large set of discharges from the recent years is analysed in order to improve our understanding of the processes behind the beam generation. It seems that despite the low toroidal field applied in the discharges (typically 1.15 T) the magnetic perturbations may be small enough to allow the acceleration and confinement of the electrons. The influence of the different components and different sections of the frequency spectrum of the magnetic perturbations on the beam generation and RE beam current is examined. Fast visible camera images are also analysed. The relevance of COMPASS runaway electron experiments for large machines is discussed. Moreover, the potential of less common diagnostic tools (Cherenkov detector, vertical ECE, ...) to clarify the role of the pre-disruption fast electron population and the influence of prompt runaway electron losses in the current quench is discussed using the recent test measurements.
|
|
|
Family house in Čechočovice
Vondráček, Petr ; Kervitcer, Marek (referee) ; Sobotka, Jindřich (advisor)
This bachelor thesis deals with the design of a family house in Čechočovice in the district of Třebíč. The family house is designed as a two-storey, partially basement building, roofed by two ramps. The project was created for the purpose of designing a permanent home for a 5-member family with the possibility of two garage parking spaces. The perimeter walls in the basement are made of ceramic blocks of the Porotherm system and insulated with extruded polystyrene. The perimeter walls of the above floors are made of Porotherm brick blocks with embedded mineral insulation. The ceiling structure is designed from the Porotherm system. The plot is slightly inclined. Part of the proposal is thermal engineering assessment, fire safety solutions and assessment in terms of acoustics and daylight. The thesis contains a drawings and technical documentation and it is composed as an implementation project.
|
guest ::
RSS feed.