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Mpembe effect - reality or fiction? (Hysteresis by water freezing).
Böhm, Pavel ; Obdržálek, Jan (advisor) ; Rotter, Miloš (referee)
The aim of this thesis was to review theoretically and experimentally so-called Mpemba eect, where the initially hot water freezes sooner than the initially cold one. Based upon already published theoretical and experimental works, a list of circumstances possibly supporting this phenomenon was created and discussed. Some situations were veried experimentally. These experiments were carried out partly in laboratory using small amounts of distilled water (less than 1 ml), partly in "kitchen conditions" using the tap water (about 200 ml) and a commercial home refrigerator. The time of freezing dened by freezing of the entire body of water was measured using the inection points of cooling curves. Unlikely to the Mpemba eect (and likely to the usual expectations), usually the sample of cold water freezes sooner than the hot one. The Mpemba eect occured rarely, mostly when the cooler was covered by the layer of the snow and the hot vessel could melt through it to reach better thermal contact than the cold vessel. Other observed cases were mostly inconclusive.
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Aeromycology - airborne fungi spores occurence
ZDVIHALOVÁ, Barbora
The seasonal variability of airborne fungi was detected in České Budějovice in the campus area during year 2009. The samples of airborne spores were collected and analysed monthly. The spores trapped on agar layer were divided into 10 morphological and 26 taxonomical groups according its morphological properties, size and colour. The highest biodiversity of airborne spores was confirmed in September and May. The opposite situation occurred in winter month. The number of fungal and bacterial colonies growing on Petri dished exposed during 24 hours in experimental site varied monthly. The fungal isolates obtained from Petri dishes represented genera belong to Deuteromycetes. The black mould fungus such as Cladosporium sp., was dominant.
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The case of weirs: Media discourse analysis
Vaňhalová, Adéla ; Kabele, Jiří (advisor) ; Vodáková, Alena (referee)
The author was concerned with the media discourse of the theme of weirs on the river Labe in newspapers MF Dnes and Ústecký deník during the period of ten years. The used methods were quantitative and qualitative content analyses. Emphasis was placed on the types of arguments used in the discourse and also on the means of argumentation [Schopenhauer 1991, Weston 2001]. Analysis discovered two basic kinds of discourse: expert and emotional. To both of these discourses were linked special kinds of means of argumentation. The expert discourse was constructed as a pure and fair argument. The emotional discourse was constructed as an insidious argument. The main conclusion derived from the analysis was about the game frames [Goffman 1999] of two sides in discourse: advocates and opponents of the weirs. To the advocates was ascribed expert economic discourse which created their dominant game frame. The advocates persuade the public about their truth through economic discourse. The opponents were first constructed as dominant in the game frame of expert ecological discourse. During time their ecological game frame was redefined by the advocates and lost its persuading power. The opponents found new game frame: "petition" political discourse. "Petition" political discourse is till now the dominant game frame of the...
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The forms of amenity migration in the Třeboňsko region
KADLEC, Lukáš
The bachelor thesis deals with amenity migration within the region of Třeboň. Amenity migration is a specific kind of migration where the direction of movement from a city to provincial areas prevails. The forms of amenity migration were mainly defined according to individual's motivation as migration for better environment or cultural specifics of given territory. The aim of the thesis is to analyse amenity migration within the region of Třeboň, to describe reasons for such migration and to find out whether expectations based on the change of the environment were met. The aim of the thesis was found through a questionnaire research and subsequent assessment.
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Mechanical and Electrical Properties of Thin Metal Films Deposited by Vacuum Evaporation
W. F. Yahya, Doaa ; Kolařík, Vladimír (referee) ; Štencl,, Jiří (referee) ; Šandera, Josef (advisor)
Thin layers are widely used in many fields of technology and today we can say that they are found in all modern technologies. Thin layers can be created in two ways, namely by chemical or physical means. This work focuses on the latter method, more particularly a technology of thermal evaporation of thin layers in a vacuum. The work focuses on the process principles during and after the evaporation. Much of the work focuses on the development and design of experiments. These experiments illustrate some of the phenomena that take place on thin films produced by the aforementioned technology. Work helps to better understand processes during formation of thin layers and properties that influence the quality and stability of thin films. In conclusion we describe results of experiments and new developments in the field of thin films deposition using evaporation under vakuum are summarized.
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Interconnection of IEEE 802.15.4 and Ethernet networks
Pavlata, Karel ; Kaczmarczyk, Václav (referee) ; Fiedler, Petr (advisor)
Táto práca sa venuje probému prepojovania rôznych typov sietí, konkrétne sietí typu IEEE 802.15.4 a Ethernetu. Motivácia vychádza zo stále sa rozširujúceho využitia bezdrátových senzorických sietí, potreby zberu dát z nich a ich integrácie. To vyžaduje aby sieť obsahovala prvky schopné preniesť dáta z bezdrátovej siete do okolitého sveta a prípadne poskytnúť konfiguračné a riadiace informácie do vnútra siete. Z hľadiska protokolov a programového vybavenia sa prepojenie uskutočňuje na rôznej úrovni, od sieťovej až po aplikačnú vrstvu komunikačného modelu ISO/OSI, s podporou hardvéru na fyzickej a linkovej vrstve.
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Language School and English Kindergarten in Horní Heršpice
Vlček, Petr ; Blažek, Petr (referee) ; Fišarová, Zuzana (advisor)
The aim of diploma’s thesis is a design od school house, exactly language school and english kindergarten. It’s a new building, designed on a flat plot no.873/21 in cadastre unit Horni Herspice, in a Brno’suburb. The language school is intended to accommodate 41 students. Kindergarten is for education preschool children. Kindergarten is designed for total capacity of 40 children. The building was designed in a rectangular shape without cellar. It is a two-storey masonry system. Both parts of the building were designed so that students and children do not meet. A schoolmaster office is located on the second floor. The building was designed from sand-lime bricks KM Beta. The thermal insulation is made from external thermal insulation composite systems ETICS, floor structure is from ceramic-concrete precast floor slabs. The major part of the flat roof structure is double-layered while the rest is a green single-layer construction.
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Development of thermal insulating materials based on waste textile fibers
Přikrylová, Pavlína ; Peterková, Jitka (referee) ; Zach, Jiří (advisor)
The increasing quantity of waste represents serious environmental, social and economic problem. Wastes produced from industry and households. A large part of the economy transforms a certain amount of raw materials to waste in their production, because it is currently emphasis is placed on finding sustainable sources of raw materials. One of the suitable secondary raw materials can be discarded textiles or waste from the textile industry. These kinds of textile waste often ends up in landfills or incinerators, so it is from an ecological and environmentally advantageous to their further use. The diploma thesis deals with the study and development of thermal and acoustic insulation materials based on textile fibers. It focuses on the legislative requirements for waste management for the sorting of textile wastes and their subsequent modification before reuse. Further it contains kinds of textile fibers and bonding technologies thermal and acoustic insulation materials. Finally, an evaluation of thermal insulation, acoustic and mechanical properties of fibrous insulation materials.
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Zlepšení metod předpovědi termické konvekce pro účely letecké meteorologie
Dvořák, Petr ; Řezáčová, Daniela (advisor) ; Brechler, Josef (referee)
This rigorous thesis is engaging by some processes in boundary layer of the atmosphere, namely rise and running of thermals, focused on vertical motion and speeds of thermals, and on methods of their measurement and forecasting. It exploits data, measured by the GPS receivers and loggers aboard of gliders and paragliders during flying over Czech Republic, and data from aerological soundings, provided by Praha-Libus observatory. Measurement was in progress in so called cross-country flight season 2007 and 2008. The solution of this research is improvement of forecasting of vertical velocity of thermals and can be used in specialised forecasts for private and recreative flying and in forecasts of thermal turbulence.
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Influence of Mn ionts in nickel hydroxide on behavour electrodes
Cirkovský, Jaroslav ; Vrbický, Jiří (referee) ; Sedlaříková, Marie (advisor)
The aim of my diploma thesis was to explore the influence of manganese ions put into nickel nitrate structure. The attention was focused mainly on the stabilization of nickel nitrate a modification, which could not change into b modification. The theoretical part of my thesis focused on applied materials, kinds of acumulators, basic parameters of acumulators and the description of chosen methods of measurement employed. It contained the electrodeposition, the impedance spectroscopy and the cyclic voltammetry. The task of the experimental part was to measure the effect of manganese ions put into potassium hydroxide structure. Proportions of Ni (nickel nitrate) : Mn (manganese nitrate) 10:0, 7:3, 5:5, 6:1 and 6:4 were blended for the measurement. By means of the electrodeposition, there was a thin layer of nickel hydroxide with an admixture of manganese ions from nickel nitrate and manganese nitrate dilution put on the nickel plate. After the spread of the thin layer on the nickel plate, the measurement by the method of cyclic voltammetry followed. The next task consisted in trying to add KOH (potassium hydroxide) anionic and cationic surfactant into the dilution.
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