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Scanning electron microscopy with low energy electrons
Mika, Filip
A method of scanning electron microscopy (SEM) of nonconductive specimens, based on measurement and utilisation of the critical energy of electron impact, is described in detail together with examples of its applications. The critical energy, at which the total electron yield curve crosses the unit level, is estimated on the base of measurement of the time development in the image signal from beginning of irradiation. The method is programmed and implemented as a module to the controlling software of the microscope type VEGA, where it secures fast search for the critical energy value.
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Analysis of the EU regulations in the field of Information and Telecommunication technologies and their effect on the single market
Hart, Ludvík ; Procházka, Pavel (advisor) ; Strejček, Ivo (referee)
The bachelor thesis describes the EU regulations in the field of information and communication technologies (ICT), particularly the Digital agenda for Europe strategy. These regulations are then tested for their influence on the European single market. The major question answered here is whether the EU regulations in field of ICT have a positive impact on the EUs single market. Answer to this question helps us evaluate the ongoing Digital agenda strategy. The impact of the regulations is analysed by induction of the following indicators, international trade, ratio of population buying online, DESI index and NRI index. With this method it is possible to tackle the wide range of fields the Digital agenda covers. I conclude this work with the statement, that European ICT regulations do have a positive impact on the single market, although are problematic due to the slow legislative process and low efficiency in addressing the regulated issue.
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Sustainable tourism development of Vysocina Region
Veselá, Markéta ; Macháček, Jaroslav (advisor) ; Vondráková, Zuzana (referee)
The diploma thesis deals with the topic of sustainable tourism development at the regional level. This phenomenon is elaborated on the example of Vysocina Region. To evaluate sustainability of its development, the potential of this touristic destination is researched regarding various areas, including key products. These are subjected to comparisons with recommendations of significant tourism organization for the purpose of assessing the sustainability of tourism. The diploma thesis also includes a comparison with other Czech regions experience as a touristic destination. Vysocina Region has favourable initial conditions for its sustainable development, especially regarding supply of key products, which include both environmentally friendly goods and cultural attractiveness contributing to the personal development of individuals and promoting intercultural tolerance. The main issue appears to be the spatial imbalance of its development in the region, caused mainly by the concentration of tourist activities to certain areas and low local initiative in the less attractive areas. The diploma thesis proposes a number of solutions, such as utilization of geocaching and products of gastroturism, supporting the foundation of local destination management organisations, promoting cycling tourism and the foundation of highly visited tourist destinations.
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Greek debt crisis
Krídlová, Adriána ; Žamberský, Pavel (advisor) ; Jedlinský, Jakub (referee)
Bachelor thesis deals with the evolution of the Greek debt crisis and is trying to best describe on the historical context, what led to it gradually. It deals with the history to the emergence of crisis and then focuses on crisis period between 2009 to 2015. The aim is to determine whether the latest rescue package was based on objective requirements of the Greek economy. The first chapter deals with the process of macroeconomic indicators and is also dedicated to the low competitiveness of Greece. The second chapter discusses the history of Greece until 2009, which can be regarded as the beginning of the debt crisis. The third chapter deals with the evolution of the crisis from 2009 to 2012. In the fourth chapter, I analyze the conformity of a Memorandum of Understanding with the real needs of the Greek economy to its recovery.
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Application of Monte Carlo simulations in banking
Boruta, Matěj ; Teplý, Petr (advisor) ; Fučík, Vojtěch (referee)
Currently, banking is exposed to huge market risks. One of those risks is occurrence of negative interest rates in the EU. Nowadays, it is important to use sophisticated and modern measurement tools and approaches to measure and manage banking risks. One of those methods is Monte Carlo simulation. This bachelor thesis is aimed at analysis and prediction of 3-month maturity Prague Interest Offer Rate (PRIBOR) for 3, 6 and 12 months with using Monte Carlo simulations. It was found that this method is suitable for prediction market variables with low volatility. If anybody uses this method, it is necessity to have in mind all pitfalls and assumptions, that this method includes, as an adequate random generated number of scenarios, approximation of correct probability distribution, independence of dataset and not least, as far as possible, to focus on factors generating randomness of market variable and not the prices, that express rather consequences of randomness than its cause. Further, the Monte Carlo prediction was compared with prognosis of the Czech Nation Bank and it was found that Monte Carlo prediction is more accurate for short term predictions. 12-month prediction of Monte Carlo simulation discovered also possible occurrence of negative interest rate at 0,05% level of probability in compare to the Czech National Bank prognosis, where was no negative interest rate predicted.
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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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Plasma spraying from liquids: plasma liquid interaction and coating build up
Tesař, Tomáš ; Mušálek, Radek ; Medřický, Jan ; Lukáč, František
Plasma spraying from liquid feedstocks is a rapidly developing field of thermal spraying since the coatings prepared from liquids exhibit some unique features, such as high hardness, thermal shock resistance or low thermal and electric conductivity. The key factor influencing the final coating character and properties is the input material which may be in the form of a suspension or a solution. Parameters of the selected suspension (solids concentration, viscosity, surface tension, chemical composition, etc.) or solution (concentration, etc.) determine its interaction with the plasma jet which strongly influences the coating buildup. This proceeding introduces the problematics of the interaction between the liquid feedstock material with the plasma jet and presents the way of evaluation of the coating buildup.
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Freezing technology of bull sperm in relation to its survivability and fertilization ability
Doležalová, Martina ; Stádník, Luděk (advisor) ; Jiří, Jiří (referee)
The aim of optimalization the insemination doses production is to provide the highest fertilization ability of spermatozoa during the demanding proces of processing fresh semen and its subsequent cryopreservation. Temperature changes causes spermatozoa damage during the cooling and freezing. Spermatozoa is exposed to cold shock and many others limiting factors, which leads to cell death and therefore to decline of fertilization ability of thawed insemination doses. For increasing spermatozoa resistance, exactly the plasma membrane resistance against cold shock was fraction of egg yolk LDL cholesterol (low density lipoprotein) at various concentrations into the comercially produced diluents added. It is believed that LDL acts possitively to plasma membrane and helps to maintain the fertilization ability of spermatozoa after thawing. Following step in the proces of insemination doses production is slow cooling of diluted semen and equilibration, when the straws are store at cooling box for 30 minutes to 240 hours. This period is necessary to penetrate of certain diluent components into the spermatazoa also maintain the balance between their intracellular and extracellular concentration. Also important is subsequent freezing temperature gradient of insemination doses. The most suitable freezing method is based on computer controlled temperature decline in freezing chamber which allows the precise control of ice crystals formation that could tear and kill the cell.
During 2012 to 2016 was repeatedly collected semen from the group of breeding bulls (n = 27, Holstein and Czech Fleckvieh breed) at AI centre. Semen which fulfill the standard entrance conditions in first step was evenly into several parts divided. For dilution the three types of comercially diluents AndroMed, Bioxcell and Triladyl with and without LDL addition were used. Into the diluents AndroMed and Bioxcell the concentration of LDL 4 %, 6 % and 8% into the dilent Triladyl 6 %, 8 % and 10 % was added. Diluted semen was filled into the glass capillares with volume 0,1 ml and temperature +4 °C. Subsequently the sample was placed to cold bath (0°C) for 10 minutes. Then the volume of capillare with physiological solution (37 °C) was mixed and for next 120 minutes was incubate. The effect of cold shock to proportion of live spermatozoa was evaluated by using Eosin and Nigrosine staining technique during heat test of spermatozoa survivability after spermatozoa heating and after 120 minutes of incubation.
The more suitable semen diluents which provide the higher spermatozoa resistance against cold shock were AndroMed and Bioxcell. Together the possitive effect of LDL addition into the diluents to lower decrease of proportion of live spermatozoa during heat test was found (P<0.05). The most suitable LDL concentration which had a favorable influence at spermatozoa resistance against cold shock was 6 % in diluent Bioxcell. Values of the proportion of live sperm were higher at the beginning of the heat test (+1.31% to + 3.2%) and after 120 minute incubation (+5.82% to +8.41%) compared to other diluents with and without addition of LDL.
In the next step the process of equilibration was optimized, is an important part of insemination doses production. The effect of the length of equilibration for subsequent fertilization ability of spermatozoa was evaluated using spermatozoa motility based of CASA and proportion of live spermatozoa after thawing and during heat survival test lasting 120 minutes (37 ° C). Suitable semen was diluted by comercially used diluent AndroMed based on soya lecithin, filled into the straws (0.25 ml), cooled and equilibrated in cooling box for 30, 120 and 240 minutes and freezed in programmable freezing box applying four types of freezing curves differing in temperature rate decline. There was used standard and by producer recommended 3. phase freezing curve, then 2. phase freezing curve, and 3. phase freezing curve with slower as well as rapid decline of temperature rate in freezing chamber, compared with standard freezing curve. The highest spermatozoa motility was found using 240 minutes of equilibration by +2.72% and +4.58% compared to other lengths of equilibration (P <0.05 to 0.01). The highest proportion of live spermatozoa was found using 120 minutes of equilibration (+6.87 % and +8.68 %). The highest average spermatozoa motility during heat test after thawing was achieved by using 2. phase freezing curve (from +2.97% to +10.37%, P <0.05), also in the proportion of live spermatozoa (from + 4.37% to +8.82%, P <0.01). When evaluating interaction between the length of equilibration and freezing curve (standard 3. phase and 2 . phase freezing curve), the highest average spermatozoa motility and proportion of live spermatozoa using 240 minutes of equilibration by both freezing curves was reached, there was no statistically significant differences. As well as, in all evaluated parts of this study the individual differences between ejaculate of bulls and within semen from one bull (P <0.05) as secondary effect were found.
To maintain good fertilization ability of semen during cryopreservation is necessary to increase the spermatozoa resistance against cold shock using addition of correct concentration of LDL into the commercially used diluents AndroMed and Bioxcell. Subsequently the fertilization ability of insemination dose is influenced by cooling, the length of equilibration and freezing. The length of equilibration 120 minutes and more as well as gentle way of freezing according to freezing curve, which ensures a gradual decrease of temperature in freezing chamber provided the higher average spermatozoa motility and proportion of live spermatozoa.
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Automatic system for gauge blocks calibration optimized for legal length metrology
Buchta, Zdeněk ; Šarbort, Martin ; Čížek, Martin ; Hucl, Václav ; Řeřucha, Šimon ; Pikálek, Tomáš ; Dvořáčková, Š. ; Dvořáček, F. ; Kůr, J. ; Konečný, P. ; Lazar, Josef ; Číp, Ondřej
This paper presents a contactless system for automatic and contactless gauge blocks calibration based on combination of laser interferometry and low-coherence interferometry. In the presented system, the contactless measurement of the absolute gauge block length is done as a single-step operation without any change in optical setup during the measurement. The optical setup is combined with compact gauge block changer with capacity 126 gauge blocks, which makes the resulting system fully automatic. \nThe paper also presents in detail a set of optimization steps which have been done in order to transform the original experimental setup into the automatic system which meets legal length metrology requirements. To prove the measurement traceability, we conducted a set of gauge block length measurement comparing data from the optimized system and the established reference system and TESA–UPC operated in Czech Metrology Institute laboratory.
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