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Treatibility of surface water
Fuks, Josef ; Palčík,, Jiří (referee) ; Kučera, Tomáš (advisor)
The aim of the master´s thesis is the topic of the treatability of surface water with the focus on the process of suspension formation. For this work I took water samples from five different places around the Brno Dam which has contended with water quality deterioration for a long period. With these water samples, the series of jar coagulation tests were done with the application of three different commonly used coagulants. In the theoretical part of the master´s thesis I deal with the composition and attributes of surface water and the technology of its treatment. Each process of treatment is briefly described here with the emphasis on the process of suspension formation. The experimental part of the master´s thesis summarizes and presents the results gained through the coagulation tests in the laboratory. I evaluate the influence of different parameters on final effectiveness of water treatment and I try to find an optimal amount of coagulant, pH and speed of fast or slow mixing. Finally I compare the suitability of each coagulant and the influence of the sampling site on the effectiveness of water treatment.
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Simulation scenarios in NS2 demonstrating knowledge of BGP and multicast
Sobotka, David ; Komosný, Dan (referee) ; Jeřábek, Jan (advisor)
Network simulation can be beneficial not only in solving problems while applying new standards or recommendations, but also primarily an aid in understanding and verifying knowledge of behaviour of communications protocols. The aim of the thesis is to create illustrative tasks in the simulation environment, Network Simulator 2 (NS-2), which are designed to verify the behavior of BGP and multicast. Created tasks are above all devoted to BGP, which is the cornerstone of routing information of all IP networks conglomerate, the Internet. The first two tasks designed for BGP use the implementation of ns-BGP and the remaining are based on the implementation of BGP++. The tasks verify both the function of basic attributes of the protocol, influencing the decision making process when routing information (AS_PATH, MED, LOCAL_PREF, WEIGHT), and furthermore the methods or parameters affecting the efficiency of the process of routing and a reduction of excessive network traffic (BGP confederation, routing, aggregation, MRAI). The last task regards multicast, more specifically the type of DM, which is a group of the so-called Dense Mode. The task illustrates how to join/leave groups and spread messages of types GRAFT and PRUNE under a constant data stream.
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TTP protocol for managing hierarchy trees of RTCP feedback channel
Müller, Jakub ; Komosný, Dan (referee) ; Burget, Radim (advisor)
TTP protocol for managing hierarchy trees of the RTCP feedback channel represents the mechanism for transferring the big amount of data from end users via the “narrow” feedback channel. We are not speaking about thousands of users but about millions of users, which are using services like IPTV. The method of a data summarization is used for this purpose in selected network nodes. The summarized message is transferred and summarized again in higher levels of the hierarchical tree. Both methods allow reducing the amount of data and help to increase information content transferred via the feedback channel. Finding of the correct end user position in a network is also very important aspect. The user must be able to find the closest summarization node with this information and starts sending out the messages to this node for processing. There are several methods for constructing and managing the asynchronous feedback channel that are introduced in this work.
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Aggregation reactions of chitosan in drinking water treatment
Leskovjanová, Jana ; Mega, Jaroslav (referee) ; Dolejš, Petr (advisor)
The diploma thesis deals with treatment of surface waters containing humic substances. The most often used method of surface water treatment is coagulation with subsequent separation of aggregates. In this study, only perikinetic coagulation phase was studied. It is the phase when aggregates are formed by the Brownian motion only, i.e. without mixing. Separation of the formed aggregates was made by centrifugation. Coagulation tests were made under the laboratory conditions with model humic water. Humic substances were added from a concentrate, which was taken from a natural peatbog. The influence of temperature on the coagulation process was studied, ranging from 5 to 22 °C. Chitosan (natural biopolymer) was used as coagulant. In present, it is not used in Czech water treatment practice yet. No effect of temperature was observed when chitosan was used as coagulant. Influence of temperature was also studied with the use of aluminium and ferrous sulphates, which are used in common praxis as coagulation reagents. Influence of the temperature was observed and is in agreement with previously reported data of pilot-plant experiments by other researchers. Spectroscopic methods were used to evaluate the coagulation efficiency and determine residual concentration of aluminium and ferrous coagulant. Chemical oxygen demand (COD) was determined for optimal doses. At first, coagulation tests were made under the laboratory temperature. This tests determined optimal aggregation time and optimal coagulant dose under low temperature. Afterwards, all coagulants used were compared at given temperatures.
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Removal of micropolutants in drinking water treatment
Hambálková, Kateřina ; Vávrová, Milada (referee) ; Dolejš, Petr (advisor)
Intrusion of pharmaceuticals into surface and drinking water is nowadays a problem, that is solved all over the world. This diploma thesis is focused on the removal of pharmaceuticals from water by coagulation. The efficiency of two coagulant agents - chitosan and ferric sulphate was compared. For comparison was used adsorption on a granular-activated-carbon. Efficiency of removal was investigated by UV-VIS spectrophotometer and HPLC.
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Production and characterization of regenerated humic acids
Uhrová, Anna ; Daniela,, Šmejkalová (referee) ; Kučerík, Jiří (advisor)
Jihomoravský lignit pocházející z dolu Mír v Mikulčicích, Lignit s.r.o. byl přesítován a vybraná frakce byla modifikována tzv. mokrou cestou pomocí dvou oxidačních (HNO3, H2O2) a dvou „amfifilních“ (kyselina octová, kyselina citronová) činidel. Alkalickou extrakcí byly získány jak huminové kyseliny z neupraveného tak předupraveného lignitu (tzv. regenerované huminové kyseliny). Na základě výsledku elementární analýzy byly vypočítány C/O a C/H poměry, které společně s FTIR spektry podaly informaci o stupni alifaticity/aromaticity a dále o stupni oxidace organického uhlíku. Pomocí vysokoúčinné vylučovací chromatografie byla stanovena distribuce velikosti huminových agregátů. K objasnění procesů probíhajících v povrchové vrstvě bylo proměřeno povrchové napětí studovaných roztoků vzorků. Získaná data byla proložena Szyszkowského rovnicí a obdržené parametry poukázaly jak na povrchovou aktivitu jednotlivých huminových kyselin tak i na povahu molekul zodpovědných za snižování povrchového napětí. Pro vzájemnou korelaci dat získaných výše zmíněnými metodami byl použit Pearsonův korelační koeficient.
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The applicability of methods that are based on the employment of composite indicators in assessing sustainable development and quality of life
Petkovová, Ludmila ; Fischer, Jakub (advisor) ; Macek, Jan (referee) ; Čadil, Jan (referee)
The main objective of this thesis is to assess the applicability of methods that are based on the employment of composite indicators when evaluating the 'sustainable development' and 'quality of live' indexes. The first issue observed in here is whether the composite indicators as such even represent a suitable tool for assessing the above mentioned area of analysis; if the answer is yes, then, secondly, under which conditions the composite indicators may be applied in the context of our analysis. After answering the questions above, it is crucial to find suitable methods for the particular steps of constructing the composite indicator for the sustainable development and quality of life categories, whereby it is also necessary to evaluate the advantages and disadvantages resulting from the application of the selected composite indicators for the purposes of the respective analysis. Within this thesis, the comparison of individual methods of constructing the indicators was performed by means of applying the individual indicators on the established set of data, as well as a subsequent comparison of results and the assessment of strengths and weaknesses of the individual methods has been done with respect to the factual side of the particular composite indicators (i.e. with respect to the sustainable development and quality of life in our case). Various composite indicators for the quality of life and sustainable development have already been established; the necessity of composing additional composite indicators for the above mentioned categories reflects the problematic nature of finding a suitable tool that would be generally accepted in this case. This thesis provides for relevant conclusions and recommendations that should contribute to establish a suitable approach towards the construction of composite indicators for the sustainable development and quality of life assessment. Furthermore, the thesis provides for the comparison of methods as employed in practical construction of composite indicators in our context with methods based on a professional theory. The professional theory/literature addresses and recommends certain methods for the construction of composite indicators in the relevant context, however, these methods are typically not applied in the practical construction of the most frequently/commonly used composite indicators for measuring the sustainable development and quality of life. The critical aspects that have been observed within comparison of the individual methods are transparency of calculation, interpretability of results, robustness of the composite indicator closely linked to the nature and character of the data, and the level of applicable compensation of the individual parameters within the respective indicator that is allowed by the particular aggregation mechanism employed. The thesis concludes on a rather questionable use of composite indicators in case of assessing the sustainable development, whereby deduces on recommending the application of composite indicators only in case of assessing the quality of life, which may also be understood as a part (sub-item) of the sustainable development and which is easier to be quantitatively expressed. In parallel, the circumstances of the quality of life are better to be compared across various items, e.g. regions. The results indicate that it is not possible to establish a uniform recommendation when selecting the most suitable method; in case of every construction of the particular composite indicator it is necessary to take into account the strengths and weaknesses of all the considered methods. At the same time, the results lead to consideration of relevancy of conclusions resulting from the evaluation of quality of life by means of composite indicators, especially by means of a single number.
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Composite indicators: the construction, usage and interpretation
Hudrlíková, Lenka ; Fischer, Jakub (advisor) ; Čadil, Jan (referee) ; Hužvár, Miroslav (referee)
This thesis brings a comprehensive view on the construction, usage and interpretation of composite indicators. Methods and techniques, which can be used for constructing composite indicators, are introduced. The focus is on their contribution to the transparent solution of the problem of correlation and compensability among underlying indicators. Transparency in construction of composite indicators is a crucial requirement for obtaining reliable results and their correct interpretation. The thesis consists of two main parts. The first part is theoretically oriented. First, the problem of adequacy and subsequently a measurement of the phenomenon by means of statistical indicators are discussed. Different methods for data normalization, setting a weighting scheme and aggregation are introduced and compared. These three steps are considered to be crucial in a process of constructing a composite indicator and thus, they are the core of the thesis. The aim is to investigate an interaction of normalization methods, weight-setting and aggregation methods, since these steps are not separate. The second part of the thesis consists of two comprehensive cases. Theoretical findings are applied and empirically verified in these cases. I investigated a robustness of the composite indicator depending on a combination of selected methods of normalization, setting weights and aggregation on a set of Europe 2020 indicators. Whereas this first case dealt with the comparative analysis of methods, the second case is focused purely on one issue -- university ranking. The proposed method reacts to criticism of currently published university rankings and takes into account specifics of the particular university as well as the exogenous background characteristics. The main added value rests in a contribution to a discussion about the improvement of construction and overall quality of composite indicators including their interpretation. I pointed out the main concerns and difficulties of composite indicators that often remain unnoticed by users and even constructors. The conclusion brings several beneficial findings, which can be used for the construction of a composite indicator and an interpretation of final scores and ranking. This work can also serve as a scientific ground for further research and development of the methodology of constructing composite indicators.
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Aggregations as an antipredator strategy in common toad tadpoles (\kur{Bufo bufo}).
BODNÁR, Tomáš
Tadpoles of many anuran species use a huge number of behavioral modifications to avoid predators. Reduced activity in presence of predators is favorite strategy for common toad tadpoles (Bufo bufo). Responses against predator cues by tadpoles of Bufo bufo in the presence of another cue of larger tadpole aggregation were tested in this study. We observed that these tadpoles responded differently to predator chemical cues than tadpoles in a small group.
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