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Monitoring of the contents of phosphorus and nitrogen in wastewater
Herka, Milan ; Repková, Martina (referee) ; Vávrová, Milada (advisor)
This master´s thesis is focused on the occurrence of phosphorus and nitrogen in effluents and methods of their determination. In the theoretical part of the thesis describes methods for the determination of nitrogen and phosphorus in waste waters, their selection and optimization methods including mobile analytics. Experimental section is devoted to the abstraction of wastewater from selected wastewater treatment plants and their analysis methods including mobile analytics and comparing them with the presentation of their results. The conclusion is drawn evaluate the content of nitrogen and phosphorus in wastewater influent and effluent from wastewater treatment plants and compared the variation of these values during the one-month study and compared with published data.
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Nitrogen and its compounds in wastewater
Venská, Petra ; Skoumalová, Marta (referee) ; Řezáčová, Veronika (advisor)
The bachelor thesis summarizes the possible forms of nitrogen and nitrogen compounds in wastewater and ways of elimination of these compounds including physical/chemical processes and biological processes. The physical/chemical methods described in the thesis are air stripping, breakpoint chlorination, sorption and membrane separation. The biological processes include nitrification, denitrification, anoxic ammonium oxidation and SHARON, CANON and OLAND systems. The experimental part is devoted to quantifying nitrates, nitrites and ammonium in wastewater samples using mobile analytical methods.
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Cleaning efficiency of vertical root filters
Opletal, Jan ; Hyánková, Eva (referee) ; Kriška-Dunajský, Michal (advisor)
The aim of this thesis was a survey about efectivity of vertical flow constructed wetlands. I find out, that vertical inttermitently flooded constructed wetland proved to be the most effecicient in pollution removal, based on data analysis form constructed wetland treatment plant in Kotenčice. The only disadvantage was weak denitrification process. Vertical filter was compared with series of horizontal and vertical continuosly flowed constructed wetland. Combination of horizontal and vertical filter was efficient enough to treat waste water, but it cannot be compared with vertical intermittently floded filter. Series of horozontal and vertical fully flooded constructed wetland had a low treatment efficiency.
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Investigation of Reliability for Solder Joints in Nitrogen Atmosphere
Vala, Martin ; Adámek, Martin (referee) ; Szendiuch, Ivan (advisor)
This thesis examines the influence of nitrogen atmosphere on the quality of the solder joint lead-free solder paste. For the solder paste were measured and set temperature profiles. Thesis includes the implementation and measurement of samples in a protective nitrogen atmosphere and without a protective atmosphere. These measurements are compared, and the conclusions were drawn for the influence of nitrogen atmosphere. The reliability and the quality of the soldered joints were investigated.
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Influence of soil pretreatment on the determination of its properties using thermogravimetry
Ragačová, Lucia ; Doležalová Weissmannová, Helena (referee) ; Kučerík, Jiří (advisor)
This diploma thesis focuses on the influence of soil pretreatment on the determination of its properties by the method of thermogravimetry, which allows the soil sample to be analyzed as a whole. The aim is to clarify how soil preparation affects the results of TG soil analysis. Soil preparation can have a major impact on its quality and thus disrupt the interrelationships of soil components that have been formed as a result of long-term pedogenesis. In this thesis, therefore, the original soils were compared with the soils, which were grinded using a ball mill before the analysis, which represented a very intensive intervention in the soil structure and was therefore a mechanically disturbed soil. A modified method of deriving weight loss has been used to evaluate the issue. The data obtained were divided into 10°C thermal intervals, in-between which the loss of weight of the individual intervals were identified. The impact of soil milling on its determinability in relation to the total carbon and nitrogen content in the soil have been compared through the correlation of data obtained from elemental analysis and TG data. Subsequently, we focused on comparing the interrelationships of the equations of ground and unground soil samples, based on the theoretical equations of the issue. As a final look, we chose autocorrelation of TG data for the obtained ground and unground samples. The results of the examination have shown that even though grinding of samples represents a very intensive intervention into the soil structure and thus the soil is mechanically disturbed, such sample preparation has only a minimal effect on the determinability of soil properties.
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Influence of Inert Atmosphere on Surface Wetting in Lead Free Soldering
Nestrojil, Michal ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This master´s thesis dealing with study of influence of inert atmosphere on the wettability of soldered surfaces. The theoretical part is discussed the issue of the soldering, solder joint, oxidation, and inert atmosphere. The glass cover with internal inert gas preheating for the wetting balance testing was prepared in the practical part. With this adjustment were realised tests, in which was examined the effect of the inert gases on the wettability of different materials combination. Further experiments were focused on plasma surface cleaning as possible flux substitution. The evaluation of these experiments were discussed in the end of this master´s thesis. Some of topics were designed for further experiments.
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Testing of Solders in Protection Atmosphere
Vala, Radek ; Jankovský, Jaroslav (referee) ; Szendiuch, Ivan (advisor)
The project deals with the overall design and construction of equipment called the desiccators for brazing in a protective atmosphere. The device was designed and manufactured cooling and heating element. For the soldering various temperature profiles have been defined and adjusted, as for SnPb as well for lead-free solders. There was a realization of samples were measured and analyzed. Finally were realized micro sections for lead free solder.
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Investigation of Reliability for Solder Joints
Toufar, Michal ; Somer, Jakub (referee) ; Szendiuch, Ivan (advisor)
It evaluates the importance of soldering in a protective atmosphere. Factors influencing the process of reflow soldering in a protective atmosphere of nitrogen. Evaluates the quality of solder joints due to a defined residual oxygen during the soldering proces. According finishes used on the resulting quality connections for two types of lead free solder.
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Optimization of the radiofrequency atomic source for deposition of GaN
Kern, Michal ; Wertheimer, Pavel (referee) ; Mach, Jindřich (advisor)
This thesis is focused on construction and optimization of radiofrequency atomic dissociation source of atomic nitrogen for depostion of GaN. The theoretical part deals with atomic sources, growth of ultrathin layers and the issue of radiofrequency circuits, with emphasis on their design using Smith chart. Methods for synthesis of GaN ultrathin layers and deposition are also discussed. In the experimental part, design and realization of various congurations of the impedance matching network is described. Using the impedance matching network a nitrogen plasma discharge was successfuly created and its spectrum was analysed. Afterwards, design and realization of a stepper motor control for the impedance matching network is described.
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The dynamics of non-structural saccharides accumulation and Rubisco activity under the elevated carbon dioxide concentration and sink manipulation at beech
Uhrová, Lucie ; Vítová, Eva (referee) ; Hrstka, Miroslav (advisor)
This diploma thesis deals with dynamic of accumulation of non-structural carbohydrates and activity of Rubisco enzyme at elevated concentration of CO2 on beech (Fagus sylvatica L.). Three years old seedlings of beech were cultivated in minisphere with ambient (385 µmol•mol-1, variant A), and with elevated concentration CO2 (700 µmol•mol-1, variant E) for four months. In every variant the first half of plants was fertilized by nitrogen (variant N+) and the second half was control (variant N-). Plants used for experiment were at first adapted for darkness for 12 hours. Subsequently tested leaves were cut off, leafstalk including short segment of branch (approximately 1 cm) was inserted into 0.7 M solution of sucrose (variant S) or water (variant V) and exposed to radiation 200 mol•m-2•s-1 for 0, 30, 60, 120, 180 minutes. Then leaf area and fresh mass of leaf blade were established, samples were fixed in liquid nitrogen and stored in deep freezer to analysis in –70 °C. Rubisco content was determined by SDS-PAGE method, Rubisco activity spectrofotometrically and content of non-structural carbohydrates by anthrone method and HPLC method. Rubisco content was significantly lower in the N- variant than in N+ variant. Rubisco content was also significantly lower in E than in A variant, which is an evidence of down-regulation. Rubisco activity is moderately stimulated at E variant with time, but differences between variant A and E are not statistically significant. Influence of sucrose feeding to Rubisco activity was not proved. Significant differences were detected by anthrone method in non-structural carbohydrates content between variants S and V, but not between variants A and E. Statistically significant increase of sucrose content with time was detected by HPLC method at variant AS, but not at variant ES.
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