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Study of microstructure evolution during final stage of sintering of advanced ceramic materials
Hrubý, Jan ; Salamon, David (referee) ; Maca, Karel (advisor)
This diploma thesis deals with the study of microstructure development during the final stage of sintering of two zirconia based ceramic materials (tetragonal ZrO2 doped with 3 mol% of Y2O3 and cubic ZrO2 doped with 8 mol% of Y2O3). Conventional, microwave and SPS sintering methods were used. Achieved relative densities and mean grain sizes were evaluated for sintered materials. It was found that the non-conventional sintering methods are capable of rapid processing of ceramics with improved microstructure compared to conventional sintering.
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3D scene reconstruction using Clifford algebras
Hrubý, Jan ; Návrat, Aleš (referee) ; Hrdina, Jaroslav (advisor)
Tato diplomová práce má za cíl seznámit čtenáře se stále ještě relativně novou a neznámou oblastí matematiky, s geometrickou algebrou. Nejdříve jsou uvedeny základní definice a poté jsou studovány vlastnosti obecné geometrické algebry. Další velká část textu se věnuje Konformní geometrické algebře, která je v současnosti jedna z nejvíce zkoumaných a aplikovaných geometrických algeber. Jsou popsány její algebraické a geometrické vlastnosti, konkrétně schopnost reprezentovat určité geometrické objekty jako vektory. Taktéž umožňuje počítat jejich průniky a konformní transformace. Další část textu je zaměřena na aplikace Konformní geometrické algebry, nejdříve k popisu kinematiky robotické ruky a poté v binokulárním viděni.
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Family house in Czechoslovakia after 1945
Dočekalová Klimešová, Lenka ; Hrubý, Jan (referee) ; Bacová, Andrea (referee) ; Šlapeta, Vladimír (advisor)
The main part of the doctoral thesis analyses the form of terraced housing in Czechoslovakia in the years 1945-1990. It searches for the original roots, the principles of formation and the characteristic types. The purpose was to find an answer to the question of where its values lie, because the state-controlled standardization negatively influenced the appearance of an average terraced house. The quest of seeking positive approaches the pre-war development of terraced housing and examines parallels between the groups of the 70s and the present. The subject is embedded in the wider framework of the state housing policy and its impact on the character of the new development. The thesis focuses on the period of the 70s, when family development culminat-ed. The main part analyzes three selected groups of terraced houses from the seventies. It is based on the study of available project documentations, which was made accessible by the archives of building authorities. Selected groups are considered in terms of public space and new types of terraced houses. The thesis highlights the diversity of typologi-cal forms of terraced houses of this period. The last part is devoted to the characteristics of terraced housing after 1990. The thesis summarizes the causes of the negative phenomena in suburban locations and shows the transformation of typical terraced houses. It analyses new approaches in urban development of family houses on selected groups. In the context of new concepts, it researches the solutions of public space and types of terraced houses. Finally, the thesis summarizes the transformation of the urban development of the terraced housing from 1945 to the present and proposes the other areas and problems suitable for exploration. The annexed documentary studies of three selected groups from the seventies, which were only partially published. Parts of the appendix are bar charts that evaluate the extent of the family development in individual time periods from 1945 to the present.
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Design analysis of the heat exchanger between the primary and the intermediate circuits of the small modular reactor DAVID
Kobylka, D. ; Hrubý, Jan ; Kordík, Jozef ; Gabriel, Dušan ; Marek, René ; Isoz, Martin
The report summarizes the joint results of the Department of Nuclear Reactors FNSPE, CTU and IT CAS, in the area of thermal and hydraulic calculations of the heat exchanger between the primary and intermediate circuits of the developed small modular reactor (SMR) DAVID. The assignment parameters were further specified during control days and with updated documentation. During the analysis of the initial system parameters, it was found that the original geometric configuration of the exchanger had a completely insufficient surface for heat transfer. A decision was made, several parameters were modified and based on a series of calculations using two independent simplified models, a reasonable configuration with a significantly smaller diameter of the tubes in a significantly larger number was chosen. The pressure losses on both sides of the heat exchanger are within normal ranges and will not cause problems with the construction of these circuits. Although there are differences between the results from both used models, their comparison shows that the chosen different calculation methods lead to approximately the same results and the models do not show fundamental errors.
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Chosen Aspects of Light in Sacred Architecture
Šťasta, Jiří ; Kopeček,, Pavel (referee) ; Hrubý, Jan (referee) ; Drápal, Jaroslav (advisor)
Different approaches to the light is emblematic reflection of the current era and it´s cultural a social aspects. The materials are still being developped but the light is everlasting participant of the architecture. The light is basic element which each architect or artist must confront and use it. Due to this we can watch the work with light, analyse it´s use during the ages of the sacred architecture. The work of an architect is situated in the intersection of theoretic and technical fields of human activities. It´s necessary that the artist or architect knows the theoretic aspects of the light but also that knows real numeral values of the coming light. It is good to know the reasons why and for what was the light used in the past and it´s also needed to have a knowledge how much of the light was used in the liturgical space. How much of the light was used in the interior in the past and how much do we use it nowadays? Is it possible to analyse the tendency in the use of the natural light? These questions are useful in forming new liturgical spaces also in nowadays. The first part of this work is focused on the theoretic aspects of the light (liturgy, theology, psychology and ergonomics). The second part of the work describes the measurements of the intensity of the natural light in the sacred spaces in the different selected churches. The conclusion compares different measured values in each sacred building and the results are included to the larger scientific and historical context. The aim of this work was to evaluate specific interior lightning conditions by unified methodology and to apply it on the larger scientific experience which regards the architectonical practice and the forming of the liturgical spaces.
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Experimental investigation of homogeneous nucleation of water in various gases using an expansion chamber
Lukianova, Tetiana ; Lukianov, Mykola ; Hrubý, Jan
Nucleation is an integral part of phase transitions and plays an important role in technology. The control of nucleation in devices such as turbines, rocket and jet engines, wind tunnels, and combustion processes is key to achieving efficient, ecologically sound operation. Our paper presents information about a modernized experimental setup used for homogeneous water nucleation research.\nThe main goal of the study is an analysis of the influence of carrier gas on homogeneous nucleation.The experimental setup based on an expansion chamber has been used for research of homogeneous nucleation over several decades and has undergone various technical improvements. In the Institute of Thermomechanics, the setup was been completely disassembled and cleaned. Pressure transducers, laser, and the data acquisition system have been replaced with modern parts. After that, the chamber was assembled, and thoroughly tested and calibrated.Our investigations were carried with argon and nitrogen as carrier gases in a range of nucleation temperatures 220 – 260 K, pressure range 80-150 kPa, at several concentrations of water vapour. The results thus obtained are consistent with literature data.The findings suggest that this experimental approach is useful for homogeneous water nucleation research.
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Intelligent beekeeping system
Hrubý, Jan ; Zeman, Václav (referee) ; Kiac, Martin (advisor)
The aim of this thesis is to design and develop an intelligent beekeeping system that can measure the frequency in the colony, the weight of the hive to monitor the loss or to inform the beekeeper if the bees are carrying honey. Furthermore, the security of the hive against theft is also being considered. Communication between multiple intelligent beekeeping systems is important for the functionality. This is why part of the work focuses on choosing the best possible communication, taking into consideration battery consumption and reliability. In this work, a many-to-one communication system of modules is used, which means that the number of hives can be freely expanded without affecting the functionality of the system. The resulting system is powered by a combination of battery and solar panels.
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On a molecular theory of water
Jirsák, Jan ; Nezbeda, Ivo (advisor) ; Hrubý, Jan (referee) ; Kolafa, Jiří (referee) ; Jungwirth, Pavel (referee)
/ Summary Water is the most important liquid on Earth, but despite an errormous cffort put into research, it is not yet fully understood. A number of thermodyna- mic anomalies have been identified in water (e.g. the maximum of density at 4"C) and their occurrence intuitively linked to a strong intermolecular associ- ative force, i.e., hydrogen bonding. Nevertheiess, so far no rigorous molecular theory has been formulated. The present work attempts to propose and apply a rigorous statistical- -mechanical approach to water. The approach is based on recent findings that the structure of associating fluids is determined rnainly by the short-range forces (both repulsive ancl attractive). This fact enables us to apply the per- turbation theory taking a short-range model as a reference. The properties of the short-range reference model are then estimated by means of a simple, so-called primitive, model. Primitive models are anaiytically constructed to reproduce the structure of the short-range reference model keeping the in- teractions simple enough for theory. The contribution of the primitive model evaluated by Wertheim's TPT2 is used as a reference term in the perturbation expansion. The equation of state is then completed by adding dispersion and dipole-dipole correction terms. Main results of the work are as...
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Influence of new cryopreservation protocol on immunogenicity and rejection of arterial allografts in rats
Hrubý, Jan ; Matia, Ivan (advisor) ; Oliverius, Martin (referee) ; Štádler, Petr (referee)
The aim of the presented experimental work was to study an acute cell and antibody- mediated immune response in recipients of abdominal aortic grafts treated by a new standardized clinical cryopreservation/slow thawing protocol used in the "Vascular graft transplant program in the Czech Republic" in a rat model. Another aim of our study was to compare the influence of two basic types of conservation protocols used in this program (cryopreservation/slow thawing protocol and cold-stored protocol) on the acute immune response after transplantation of such treated abdominal aortic grafts in rats. Cryopreserved abdominal aortic grafts were transplanted syngeneously between Lewis rats (CRYO-ISO group, cryopreservation period 172.6 days) and allogeneically between Brown-Norway and Lewis rats (CRYO-ALO group, cryopreservation period 179.3 days). The grafts were explanted on day 30 after transplantation and subsequently examined by histological and immunohistochemical methods, focusing on typical signs of acute rejection in the three basic layers of the aortic wall. We monitored the presence of endothelial cells, signs of intimal hyperplasia, tunica media thickness, the presence of necrosis and deposition of imunoglobulin class G in this layer, the number of CD4+, CD8+ and LEW MHC II+ immunocompetent cells...
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Formation and transformation of atmospheric aerosol in boundary layer
Holubová Šmejkalová, Adéla ; Ždímal, Vladimír (advisor) ; Řezáčová, Daniela (referee) ; Hrubý, Jan (referee)
Title: Formation and transformation of atmospheric aerosol in boundary layer Author: Mgr. Adéla Holubová Šmejkalová Institute: Institute for Environmental Studies Supervisor: Ing. Vladimír Ždímal, Dr., Institute of Chemical Process Fundamen- tals of the CAS Training workplace: Institute of Chemical Process Fundamentals of the CAS Abstract: The experimental measurement of aerosol clusters from 1.17 nm in size was carried out from August 2016 till December 2018 at the National Atmospheric Observatory Košetice. Atmospheric conditions leading to aerosol clusters stabili- zation, fresh particles formation and particle growth were analyzed. Data of days with no new particle formation confrmed the connection between mixing layer height development and decrease of total aerosol number concentration together with lower gaseous pollutant concentrations. On the contrary, new particle for- mation process overcomes dilution of the atmosphere by increasing the number of freshly nucleated particles. Only decreasing gaseous pollutant concentrations were observed during these events. The atmospheric boundary layer was high du- ring new particle formation events that can mean enrichment of the atmosphere by other components transported by long-range transport or some transfer from the free troposphere. The measurement in...
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