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Detection of signal electrons at higher pressure in the specimen chamber
Jirák, Josef ; Autrata, Rudolf ; Špinka, Jiří
The advantages of the scanning electron microscopy working at higher pressures in the specimen chamber are connected with the possibility of observation of specimens structures, which are difficultly observable without previous preparation for microscopes working with pressures in the specimen chamber under 10.sup.-2./sup. Pa. The pressure in the specimen chamber up to approx. 2000 Pa brings the possibility of observation of specimens, which release gases, specimens containing liquid phase, including wet biological preparations, reactions on the phase interfaces, etc. At higher pressures in the specimen chamber it is also not necessary - due to neutralisation of the surface negative charge by gas ions - to coat electrically non-conductive specimens by a conductive layer.
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Fiscal rules in selected EU countries between 2004-2015: sensible method for consolidation of public finances or fad of politicians?
Veselý, Lukáš ; Strejček, Ivo (advisor) ; Chmelová, Pavla (referee)
The subject of fiscal rules is very topical issue. The rise of public debt in certain developed countries resulted in what is sometimes called "debt crisis". Debt of those countries which is higher than their annual gross domestic product is viewed as unpayable by some economists. The main objective of this thesis has been to prove or disprove hypothesis that the fiscal rules studied in this paper are an effective solution for public finance consolidation. This verification was based on the analysis of fiscal rules functioning in selected countries between 2004 and 2015. As per results of analysis the paper aims to give recommendations for the Czech financial constitution proposal. The actual results of inquiry proved the hypothesis. Well-chosen fiscal rules are the right way towards fiscal consolidation, provided they are observed. Fiscal rules making thus requires an emphasis to be placed on the well-formulated exit clauses altogether with prospective sanctions. The current Czech financial constitution proposal is built on the correctly picked fiscal rule type, although the reference value lacks economic sense and it would not lead, with a high degree of probability, towards fiscal consolidation.
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Tax and legal issues of real-estate business in Austria
Banctel, Kristýna ; Filipová, Vladimíra (advisor) ; Drozen, František (referee)
The purpose of this study is to compare tax and civil-law issues concerning property business in Austria and in Czech Republic in 2016 and to investigate the efficiency of the current legislation against the real estate bubble. The theoretical part of this study contains selected demographic and price statistics concerning real estate in both countries and focuses on the description of the existing law currently in effect in both compared countries. The practical part analyses tax and transactions costs that concern property trading and a comparison of possibilities of amortisations and rentability of a rented flat in both countries.
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Aspects of the virtualization of higher education and its comparison in the CZ and US
Dlauhá, Dominika ; Šedivá, Zuzana (advisor) ; Pour, Jan (referee)
The topic of this thesis is the evolution of online higher education in the CZ and US, from its beginnings to its current state. Emphasis is placed on describing MOOCs and virtualization in education, ranging from technological, pedagogical and didactic aspects to legislature and finance. A survey was conducted to determine the interest in online courses at the University of Economics, Prague and experience with online learning, resulting in an outline of the future development in this area.
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INFLUENCE OF LASER CUTTING AND PUNCHING ON MAGNETIC PROPERTIES\nOF ELECTRICAL STEEL M470-50A
Bulín, Tomáš ; Švábenská, Eva ; Hapla, Miroslav ; Ondrůšek, Č. ; Schneeweiss, Oldřich
Electrical steel M470-50A belongs to the most often used materials in electrical machines. Due to this fact, it is desirable to know the magnetic parameters after processing raw sheets into the required shape. Basic parameters of mechanical, electrical, and magnetic properties of the sheets are usually obtained from the producer but the magnetic properties are changing in dependence on additional machining processes. The aim of this study is to describe changes in parameters of magnetic behavior after punching, laser and spark cutting of the original sheets. The basic information of structure was obtained by optical and scanning electron microscopy. The magnetic parameters were acquired from the measuring of magnetic hysteresis loops in dependence on saturation fields and frequencies. The results are discussed from the point of view of applied\ncutting technology with the aim to obtain the best magnetic parameters and consequently a higher efficiency of the final product. Results can be used as input parameters in simulation of the electrical machine.
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The tax system reduces motivation to return to work among mothers with young children: recommendations and evaluation
Šatava, Jiří
In the Czech Republic, the overall taxation of work, i.e individuals' income tax together with social security and health insurance contributions, places a heavy burden even on the relatively low earnings of so-called second earners in households, i.e. partners with lower earnings. These peoples' work activity is, however, generally very sensitive to the level of taxation. A large group of these earners is made up of mothers with young children. Mothers who are the second earner in their household are subject to a participation tax rate (PTR) up to 30 % higher than their partners, and yet a higher PTR results in lower motivation to work. Women with children and low earning potential are subjected to the highest PTRs in comparison with their partners.
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Role of Psb28 proteins in the biogenesis of the Photosystem II complex in the cyanobacterium Synechocystis sp. PCC 6803
BEČKOVÁ, Martina
The thesis focuses on the role of Psb28 proteins, namely the Psb28-1 and its homolog Psb28-2, in the biogenesis of the Photosystem II complex (PSII) in the cyanobacterium Synechocystis PCC 6803. The aims of this work were to localize the proteins within the cells, and to determine their function. A fraction of both Psb28 proteins was identified in the monomeric PSII core complexes but most proteins were found in the unassembled protein fraction associated with thylakoid membranes. Psb28-1 was mostly detected as a dimer while Psb28-2 as a monomer. Psb28-1 also differed from Psb28-2 by its higher affinity to the PSII core complex lacking CP43 antenna. Characterization of Psb28-less mutants suggested regulatory function of the proteins in PSII biogenesis in connection with chlorophyll biosynthetic pathway. Analysis of preparations isolated using FLAG-tagged versions of Psb28 proteins showed their association with Photosystem II - Photosystem I supercomplexes, especially under increased irradiance, and supported a role of Photosystem I in the PSII biogenesis.
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Sorption and Stabilization of Metals/Mettalloids by Innovative Synthesized Sorbent Amochar.
Ouředníček, P. ; Trakal, L. ; Komárek, M. ; Pohořelý, Michael
Remediation of contaminated soil which is based on stabilization and immobilization of potential\nhazardous substance by sorption materials has been studied intensively nowadays. Biochar – activated organic carbon belongs to this group of stabilizing agents which can adsorb wide range of contaminants, including metals/metalloids. Surface area of the biochars is quite large in general and functional groups (e.g. COO–) can form chelates or alkaline elements on the surface, which is represented by cation exchange capacity. Altogether with the high pH values (7.00 – 10.00), biochars are quite effective sorbents and can adsorb metals/metalloids from the solution (ground water), especially in acidic soils (in the environments affected by intensive mining activities). Sorption\neffectiveness can be increased (especially for As (V) or Cr (VI) sorption) by modification of biochar by various types of secondary oxides. Innovative sorbent AMOchar (AMO + biochar) has been synthesized currently. The product was prepared by adding of biochar to the reaction solution during amorphous manganese oxide (AMO) synthesis. The AMOchar was formed mainly by Mn-oxalates which had coated surface of the pristine biochar. AMOchar composite was able to remove significantly higher amounts of various metal(loid)s from the solution despite the rather high pH of the material. Sorption effectiveness was high not only in case of Pb (II) sorption (almost 99%), and Cd(II) (51.2%), but also a very high amount of As(V), 91.4%. Additionally, both AMOchar composite was able to reduce Mn leaching. This can avoid potential post-contamination caused by the dissolution of less stable Mn-oxalates as observed in the pure AMO.
Fulltext: content.csg - PDF Plný tet: SKMBT_22316111113040 - PDF
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Effect of snowpack on runoff generation during rain on snow event.
Juras, Roman ; Máca, Petr (advisor) ; Ladislav , Ladislav (referee)
During a winter season, when snow covers the watershed, the frequency of rain-on-snow (ROS) events is still raising. ROS can cause severe natural hazards like floods or wet avalanches. Prediction of ROS effects is linked to better understanding of snowpack runoff dynamics and its composition. Deploying rainfall simulation together with hydrological tracers was tested as a convenient tool for this purpose. Overall 18 sprinkling experiments were conducted on snow featuring different initial conditions in mountainous regions over middle and western Europe.
Dye tracer brilliant blue (FCF) was used for flow regime determination, because it enables to visualise preferential paths and layers interface. Snowpack runoff composition was assessed by hydrograph separation method, which provided appropriate results with acceptable uncertainty. It was not possible to use concurrently these two techniques because of technical reasons, however it would extend our gained knowledge. Snowmelt water amount in the snowpack runoff was estimated by energy balance (EB) equation, which is very efficient but quality inputs demanding. This was also the reason, why EB was deployed within only single experiment.
Timing of snowpack runoff onset decrease mainly with the rain intensity. Initial snowpack properties like bulk density or wetness are less important for time of runoff generation compared to the rain intensity. On the other het when same rain intensity was applied, non-ripe snowpack featuring less bulk density created runoff faster than the ripe snowpack featuring higher bulk density. Snowpack runoff magnitude mainly depends on the snowpack initial saturation. Ripe snowpack with higher saturation enabled to generate higher cumulative runoff where contributed by max 50 %. In contrary, rainwater travelled through the non-ripe snowpack relatively fast and contributed runoff by approx. 80 %.
Runoff prediction was tested by deploying Richards equation included in SNOWPACK model. The model was modified using a dual-domain approach to better simulate snowpack runoff under preferential flow conditions. Presented approach demonstrated an improvement in all simulated aspects compared to the more traditional method when only matrix flow is considered.
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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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