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Changes in gas exchange of selected genotypes of poppies depending on the influence by low temperature
Málek, Jan ; Hnilička, František (advisor) ; Orsák, Matyáš (referee)
The Czech republic is one of the biggest Opium poppy producers. In 2015, this plant was grown in an area of approx. 32 650 ha. Since the poppy is usually sown quite soon in the spring, it can be damaged (or negatively affected) by low temperatures. The main objective of this Bachelor thesis was to determine the speed of gas exchange in several poppy species affected by low temperatures.
In this research, altogether 12 various genotypes of Opium poppy (Papaver somniferum L.) were included in (development phase 35 BBCH). These were concretely following poppy species: CM 112, Sokol, Major, Opál, Florián, Albín, Postomi, Marianne, Budha, Lazur, Aplaus and Orbis. Under controlled conditions of a clima-box (Conviron), the plants were exposed (within 1 week) to daily temperatures of 10 °C and night temperatures of -5 °C. After one week, the night temperature was increased to 5 °C, while the daily temperature remained the same (i.e. 10 °C). In following two weeks, there was measured the photosynthesis- and transpiration- speed (using the infrared gas analysator LDpro+SD).
Base on measurements made, there was stated, that there could be noted quite big differences in photosynthesis- and transpiration- speed in particular poppy genotypes involved. This fact proves the existency of obvious differences in gas exchange speed of particular poppy species included in this research. Between the particular measurement terms, there could be also noted differences in photosynthesis- and transpiration speed, which proves the influence of low temperatures on photosynthesis- and transpiration speed.
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Drying of moist materials at low temperatures
Gregor, Jakub ; Neuberger, Pavel (advisor) ; Adamovský, Radomír (referee)
The aim of this work was to develop a literature review on the issue of drying moist materials at low temperatures. The first part is devoted to an overview of drying theory, distribution and classification of dryers and a brief analysis of the most common of them. There is also addressed the issue of the effect of temperature on the dried material and the nature of low-temperature drying.
The second part of the research is concerned with the broadest current method of drying at a low temperature, which is called lyophilisation. There is mentioned principle of the method, the process of drying, processing equipment, methods and examples of activities and overview of key manufacturers.
The third part is devoted to other drying techniques that can be used for effective drying at low temperature and their comparison.
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Very low temperature measurement
Mráz, Dominik ; Harabiš, Vratislav (referee) ; Chmelař, Milan (advisor)
This bachelor thesis is focused on low temperature measurement, respectively on temperature sensors classsification, their accuracy, temperature range and linearity. It deals especially in use of these sensors in cryogenic applications. It contains temperature sensor block diagram, including the description of each block. It also contains schematic designs with description of each design’s function, components and the reason why it’s used. Additionally the realization of the temperature sensor is described and it’s testing.
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Very low temperature measurement (to -160 of degrees Celsius)
Vlček, Josef ; Rampl, Ivan (referee) ; Chmelař, Milan (advisor)
his semestral thesis deals with measurement of low temperatures (down to -160 degrees Celsius). This thesis describes basics of cryotherapy and its practical implementation. It also deals with different types of temperature sensors which means theoretical description of their work, thein advantages and disadvantages. The main goal is to put a recommendation of which of this sensors is the most suitable for practical implementation of the thermometer.
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Vliv lepidla na pevnost lepených spojů za nízkých teplot
Bouška, Martin
This bachelor's thesis deals with the influence low temperatures environment and used adhesive to strength of adhesive joints of massive wood. The tested joins of oak and spruce wood were glued polyurethane adhesive and mixed urea melamine formaldehyde adhesive. The joins were exposed to low temperatures (from 5 °C to -30 °C) and subjected shear tension test according to ČSN EN 205. For comparison a result of strength at low temperatures was performed also test the strength of adhesive joints at room temperatures.
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