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Conditions of observation of electrode masses in environmental scanning electron microscope
Drnovský, Radek ; Michálek, Martin
When an electrochemical battery operates, oxides and sulphides are produced on the interface between the electrode mass and collector. This causes a short battery life and less efficiency. For the study of these phenomena the observation of the structure of the surface of the electrode mass in the ESEM was chosen. The electrode mass is operated in a liquid of an electrolyte. When the specimen is observed in the classic scanning electron microscope (SEM), its surface is enormously dried by the vacuum and its state does not correspond to the original state in the battery. Observation in ESEM allows the use of working pressures in the range from tens to thousands of Pa, and the drying of the specimen is suppressed. When the working conditions in the specimen chamber are changed, the quality of given images changes too. The aim of the experiment is to determine optimum conditions for the attainment of a good-quality image of the structure of the electrode mass surface in the ESEM.
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Clustering and regression analysis of micro panel data
Sobíšek, Lukáš ; Pecáková, Iva (advisor) ; Komárek, Arnošt (referee) ; Brabec, Marek (referee)
The main purpose of panel studies is to analyze changes in values of studied variables over time. In micro panel research, a large number of elements are periodically observed within the relatively short time period of just a few years. Moreover, the number of repeated measurements is small. This dissertation deals with contemporary approaches to the regression and the clustering analysis of micro panel data. One of the approaches to the micro panel analysis is to use multivariate statistical models originally designed for crosssectional data and modify them in order to take into account the within-subject correlation. The thesis summarizes available tools for the regression analysis of micro panel data. The known and currently used linear mixed effects models for a normally distributed dependent variable are recapitulated. Besides that, new approaches for analysis of a response variable with other than normal distribution are presented. These approaches include the generalized marginal linear model, the generalized linear mixed effects model and the Bayesian modelling approach. In addition to describing the aforementioned models, the paper also includes a brief overview of their implementation in the R software. The difficulty with the regression models adjusted for micro panel data is the ambiguity of their parameters estimation. This thesis proposes a way to improve the estimations through the cluster analysis. For this reason, the thesis also contains a description of methods of the cluster analysis of micro panel data. Because supply of the methods is limited, the main goal of this paper is to devise its own two-step approach for clustering micro panel data. In the first step, the panel data are transformed into a static form using a set of proposed characteristics of dynamics. These characteristics represent different features of time course of the observed variables. In the second step, the elements are clustered by conventional spatial clustering techniques (agglomerative clustering and the C-means partitioning). The clustering is based on a dissimilarity matrix of the values of clustering variables calculated in the first step. Another goal of this paper is to find out whether the suggested procedure leads to an improvement in quality of the regression models for this type of data. By means of a simulation study, the procedure drafted herein is compared to the procedure applied in the kml package of the R software, as well as to the clustering characteristics proposed by Urso (2004). The simulation study demonstrated better results of the proposed combination of clustering variables as compared to the other combinations currently used. A corresponding script written in the R-language represents another benefit of this paper. It is available on the attached CD and it can be used for analyses of readers own micro panel data.
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IT requirements management of insurance company
Dvorský, Petr ; Bruckner, Tomáš (advisor) ; Jungmannová, Barbora (referee)
The first part of thesis deals with theoretical knowledge, thus defining the concepts of recommendations from the field of requirements management. The second part focuses on the identification, analysis and subsequend design solutions to problems arising from working with the requirements. Methods for identifying problems are carried out workshop, participant observation and interviews with employees from the IT sector of the insurance company. The outputs of this work are proposals for improving requirements management, some of them are successfully applied in Kooperativa. The first draft, which was applied to create a process library. Further, of four different types of prioritization was selected and applied method that is defined by ITIL. Other outputs are design of new user interface of requirements software and starting to design a Change Advisory Board, which is compared to ITIL enhanced with additional features. Further was established Business Consultant Department, which has task of efficiently collecting client requirements and the supporting documents were created for this department.
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Marketing mix of the fitness centre
Choutková, Aneta ; Khelerová, Vladimíra (advisor) ; Vojtíšek, Zdeněk (referee)
The aim of the thesis is to define and evaluate the marketing mix of the fitness centre World Gym Fitness Group Inc. and to recommend changes that would increase the efficiency of the marketing mix. The theoretical part is divided into two chapters and focuses on marketing mix of services and marketing environment. Within the crucial practical part there has been run a research to determine the mission of the company and clients´ satisfaction. The research is based on direct observation. The practical part contains at first general characteristics of the World Gym company. The next chapters are focused on the individual parts of the marketing mix of the fitness centre. The marketing mix includes services, price, promotion, distribution, physical environment and people. At the end all findings are summarized in the SWOT analysis and recommendations are designed to increase the efficiency of the marketing mix of the fitness centre.
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ELECTRON BEAM REMELTING OF PLASMA SPRAYED ALUMINA COATINGS
Matějíček, Jiří ; Veverka, J. ; Čížek, J. ; Kouřil, J.
Plasma sprayed alumina coatings find numerous applications in various fields, where they enhance the properties of the base material. Examples include thermal barriers, wear resistance, electrical insulation, and diffusion and corrosion barriers. A typical structure of plasma sprayed coatings, containing a multitude of voids and imperfectly bonded interfaces, gives them unique properties - particularly low thermal conductivity, high strain tolerance, etc. However, for certain applications such as permeation barriers or wear resistance, these voids may be detrimental.\nThis paper reports on the first experiments with remelting of plasma sprayed alumina coatings by electron beam technology, with the purpose of densifying the coatings and thereby eliminating the voids. Throughout the study, several parameters of the e-beam device were varied - beam current, traverse velocity and number of passes. The treated coatings were observed by light and electron microscopy and the thickness, structure and surface morphology of the remelted layer were determined and correlated with the process parameters. Based on the first series of experiments, the e-beam settings leading to dense and smooth remelted layer of sufficient thickness were obtained. In this layer, a change of phase composition and a marked increase in hardness were observed.\n
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Characterization of FRET sensor
Datinská, Vladimíra ; Klepárník, Karel ; Belšánová, B. ; Minárik, M. ; Foret, František
In this study, we present characterization of sensor based on Fӧrster resonance energy\ntransfer (FRET). The sensor is composed of ssDNA chain attached to a laboratory\nsynthesized quantum dot (QD). A complementary chain of a sample is labeled by a\nluminescent dye. When the dsDNA hybrid is formed, the energy from the QD (donor)\nis transferred to the dye (acceptor) and FRET is observed as a decrease of QD\nluminescence emission intensity and an increase of dye luminescence emission\nintensity.
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Access to Information and Access to Justice in Environmental Matters in the Republic of Irealand and the Czech Republic
Vítková, Martina ; Stejskal, Vojtěch (advisor) ; Sobotka, Michal (referee)
This diploma thesis deals with access to environmental information and access to justice in environmental matters introduced by Aarhus Convention in the specific conditions of Czech Republic and Ireland. These rights are considered to be very important tools for environmental protection. At a time when people threaten their own existence by negative interference with the environment it is necessary that effective means for its protection exist. These means are access to environmental information and access to justice in environmental matters, which together can be called as environmental procedural rights. The first chapter of this thesis presents the sources of environmental procedural law and observes the development of law at international, European and national level. The most important international document in this field is the Aarhus Convention that was adopted in 1998 by most of the European countries and that provides for access to environmental information, access to justice and public participation in environmental decision-making. This convention has largely affected the law of the European Union, where several directives has been adopted, including most importantly the Directive 2003/4/EC on access to environmental information and the Directive 2003/35/EC on public participation in...
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Determination of Total Antioxidant Capacity in Select Food products and Dietary Supplements by Flow Injection Analysis with Chemiluminiscent Detection
Průchová, Karolína ; Rychlovský, Petr (advisor) ; Hraníček, Jakub (referee)
In this diploma thesis, a functional method for the determination of total antioxidant capacity by flow injection analysis with the chemiluminiscent detection was successfully developed. Luminol in carbonate buffer (composed of Na2CO3, NaHCO3 and (NH4)2CO3), with Cu2+ ionts as a catalyst, was used as a chemiluminiscent reagent. Chemiluminiscent radiation was induced by a diluted solution of hydrogen peroxide, a long-lasting chemiluminiscence was observed. First part of this thesis is dedicated to the optimalisation of the experimantal conditions for antioxidant capacity measurements as well as to the construction of apparatus for flow measurings. L-ascorbic acid was used as a standard. In the second part of this thesis the freshly developed method was used to determinate total antioxidant capacity of real food product simples, namely tea and coffee simples, beers, wines, chocolates, fresh fruit juices and selected food supplements. Results of this analysis were expressed as a vitamin C equivalent antioxidant capacity (VCEAC) related to standard, in mg/ml for liquid simples and in g/mg for solid simples. Results obtained are: tea simples 53 - 347 mg/1g of dried product, coffee simples 399-449 mg/g of dried product, beers 1,1-1,4 mg/ml, wines 4,2 - 4,8 mg/ml, fresh lemon juice 4,7 mg/ml, fresh kiwi juice 2,1...
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Study of physiology and searching of proteomic tools useful in suppression and detection of Varroa destructor
Holenková, Martina ; Erban, Tomáš (advisor) ; Titěra, Dalibor (referee)
This work is focused on the study of physiology and proteome of the the mite Varroa destructor and on comparison with the honeybee Apis mellifera. Varroa is currently a major problem for beekeeping, because infects most of the colonies. The control of the mite can not be done without residues both in the hive and for example in the honey or other resources used by the man. Another problem can also be the simultaneously discussed issue of the connection with the Colony Collapse Disorder. The internal anatomy of V. destructor was studied by using paraffin histology. On histological sections stained using hematoxylin and PAS was possible to observe the mite digestive system, but also egg, ovaries or brain. The primary aim of this study was to identify the proteins of mite V. destructor and bee A. mellifera as a host of this parasite. For the electrophoretic separation was used two- dimensional gel electrophoresis, where the second dimension was carried out using 12% and 15% SDS-PAGE. The most abundant spots were selected for analysis using MALDI TOF/TOF mass spectrometry. The most abundant protein identified in samples of V. destructor was hexamerin, arginine kinase or hemelipoglycoprotein precursor. Hexamerins were also identified as the major proteins in the pupae samples. On the contrary the main...
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Arctic tundra dendrochronology
Lehejček, Jiří ; Svoboda, Miroslav (advisor) ; Monika, Monika (referee)
Historically unprecedented environmental change in the Arctic ecosystems is often given into the context of its past and possible future development. In the region where instrumental meteorological observations are scarce archives need to be investigated in order to address this issues. The comprehensive synthesis one of the archives: long-live circumpolar evergreen Juniperus communis L. shrub is presented here. 20 individuals from southwest Greenland were investigated at the cell anatomy level to understand the ecology of the species and unhide its potential for environmental and climate reconstructions. The findings are as follows:
i) Stop of exponential cross-sectional conduit-lumen widening with increasing age is in contrast with conduit-lumen nature of trees. This indicates that shrubs do not need to saturate their water and nutrient demands via traits of classical hydraulic conductivity law but rather developed different mechanisms. Extreme weather conditions result in prostrate growth form. However, different weather factors probably influence shrub growth differently: While snow and wind act mechanically (a), temperature influences the form of growth physiologically (b). a) So long as the young shrub stem has high resilience to bend back to an upright position after snow melt and so long as it can withstand the wind during the vegetation season it most likely grows upright and the conduit-lumens widen. b) Temperature, resp. freeze-thaw events are responsible for the shrubs preference of safety (finite size of conduit-lumens) over hydraulic efficiency, thus not allowing for more primary growth. All of these (and other) factors are apparently working together and the transition of vertical to more horizontal growth is gradual. As a consequence, the conduit-lumen sizes may not have to be further increased (due to ecophysiological restrictions possibly also must not) because water is no longer transported against gravity.
ii) Observed age/growth trend has to be taken into consideration for further employment of the wood anatomical parameter in paleoenvironmental studies. That is, shrub cell parameters can only be used for this purposes if correctly detrended. This allows for more accurate as well as longer reconstructions because youth trend was often neglected in reconstructions based on shrub annual-rings.
iii) The south-western Greenland Ice-Sheet (GrIS) melt rates reconstruction is presented for the whole 20th century. This part of GrIS is considered as the most active. According to the presented reconstruction current GrIS melt rates are not uncommon for the last century being comparable to first decades of 20th century. This finding is particularly important contribution to the debate on Atlantic meridional overturning circulation (AMOC). Too high fresh water inputs into the Northern Atlantic from GrIS melting may slow down or even stop the AMOC which would result in more continental climate in Europe. Presented results indicate that this threshold lies higher than observed current melt rates of GrIS.
Fascinating Juniperus comunnis species has shown to be able to address many ecological as well as environmental open questions and due to its longevity and abundant distribution has a great potential to become an important player in the Arctic research.
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