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Czechs and their satisfaction with environmental conditions
Veselský, Michal
In May 2009 CVVM cocerned on chosen environmental issues. People were more satisfied with state of environment at their place of residence (70 %) than in Czech republic in general (58 %). Respondents were most satisfied with accessability of free nature (84 % "satisfied"), quality of drinking water (78 %) and cleanness of nature (72 %). On the other hand respondents were dissatisfied with impact of density of traffic on the environment (67 % "dissatisfied").
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Detection of Eccentricity and Broken Rotor Bar Faults by Means of Monitoring of Current and Magnetic Flux Density Spectrums
Ishkova, I.
In this paper, faults detection and classification using motor current signature analysis (MCSA) and monitoring of magnetic flux density in air-gap of the machine is presented. A series of simulations using the models of three phase cage induction motor performed in different fault condition, such as static, dynamic and mixed eccentricity and broken rotor bars. Designed models were implemented with the help of finite element method to provide data that makes it possible to diagnose presence of any type of fault, as well as to analyze obtained and calculated results. Models were designed on the basis of characteristics and parameters of real motor. The results are illustrated in the form of graphs that makes visible illustration for effectiveness of the used diagnosis method.
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Ultrastructural changes in human neural cells after infection with tick-borne encephalitis
TESAŘOVÁ, Martina
Annotation: Human cells of neuronal origin represent an excellent tool for the investigation of neuropathogenesis of TBE. The maturation, replication process of tick-borne encephalitis virus (TBEV) and ultrastructural changes induced by infection in the neuroblasts cell line (UKF-NB-4) was studied by electron microscopy. I compared electron microscopical aspects (appearance) of TEM images of neuroblasts cells prepared by (1) conventional chemical fixation, resin-embedding and sectionig; (2) rapid freezing of cell monolayers at high pressure and sectioning of freeze substituted samples. The most interesting fact, however, is that vitrification preserves the cell in close to native state, whereas chemical fixation and dehydration can not take place without extensive intra- and intermolecular cross-linking and aggregation. The appearance of the cytoplasm and nucleoplasm of neu-roblasts cells were different in conditions (1) and (2). The excellent ultrastructure of the cytoplasmic and nuclear membranes and organels of neuroblasts cells processed by (2) confirmed the potentional of the method for preservation of cellular fine structures. The infection of neuroblastoma cells was associated with number of major morphological changes, including proliferation of membranes of the rough endoplasmic reticulum and rearrangement of cytoskeletal structures. The viral particles were located mainly in the cisterna´s of ER but also in the cytoplasm. In the cytoplasm I observed virions in the asso-ciations with microtubules and neurosecretory dense core vesicles. The transport of viral particles inside of the transport vesicles was obsereved from ER to Golgi apparatus. Free nucleocapsids were not confirmed. The observed pattern corresponded to both trans and cis type of maturation. The TBEV-infected neuroblasts cells exhibited either apoptotic or necrotic morphological changes. I observed the apoptotic signs (condensation, margination and fragmentation of chromatin in nucleus) and other alterations, such as disorganisation of cytoplasm, presence of the vacuoles and high density of cytoplasm. This report also de-scribes scanning electron microscope study of the surface features of neuroblasts cells. We observed virus-mediated cytopathic effect. The cells infected with TBEV were rounded with rough and rugged topography.
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Matter Models in General Relativity with a Decreasing Number of Symmetries
Gürlebeck, Norman ; Bičák, Jiří (advisor) ; Fraundiener, Jörg (referee) ; Ledvinka, Tomáš (referee)
Title: Matter Models in General Relativity with a Decreasing Number of Sym- metries Author: Norman Gürlebeck Institute: Institute of theoretical physics Supervisor: Prof. RNDr. Jiří Bičák, DrSc., dr.h.c. Abstract: We investigate matter models with different symmetries in general relativity. Among these are thin (massive and massless) shells endowed with charge or dipole densities, dust distributions and rotating perfect fluid solutions. The electromagnetic sources we study are gravitating spherical symmetric condensers (including the implications of the energy conditions) and arbitrary gravitating shells endowed with a general test dipole distribution. For the latter the Israel formalism is extended to cover also general discontinuous tangential components of the electromagnetic test field, i.e., surface dipole densities. The formalism is applied to two examples and used to prove some general properties of dipole distributions. This is followed by a discussion of axially symmetric, stationary rigidly rotating dust with non-vanishing proper volume. The metric in the interior of such a configuration can be determined completely in terms of the mass density along the axis of rotation. The last matter models we consider are non-axially symmetric, stationary and rotating perfect fluid solutions. This is done with a...
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Sound analyzer
Daniel, Jiří ; Fiala, Jiří (advisor) ; Mareš, Martin (referee)
Title: Sound analyzer Author: Jiří Daniel Department: Department of Applied Mathematics Supervisor: doc. RNDr. Jiří Fiala, Ph.D., Department of Applied Mathematics, Malostranské nám. 25, 118 00 Praha 1 Supervisor's e-mail adress: fiala@kam.mff.cuni.cz Abstract: The goal is to program a utility that would conduct the spectral analysis of the audio signal. Special attention will be given that the analysis was carried out in real time (here it is necessary to optimize data flows depending on the computational power of machines) and to allow the user to specify the width and the density of each frequency band. The work can be extended to the preparation of spectral filters, which would carry out the downstream signal conditioning. Keywords: spectral analysis, Fourier transformation, digital band-pass filter, feedback
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The development of fire-resistant repair mortars with fine-grained filler
Záruba, Jiří ; Gross,, Tomáš (referee) ; Bydžovský, Jiří (advisor)
The diploma thesis is focused on fire-resistant repair mortar with fine-grained filler. The aim of this work is the research and development of fine-grained Mortars resistant to high temperatures, which are characteristic at the beginning of the fire. The theoretical knowledge with subsequently realized laboratory verification was used. At-tention was paid to the masses based on the mixed binder comprising cement and blast furnace slag, respectively. high-temperature ash. Cellulose fibres were used as the dis-persed reinforcement. Two kinds of aggregate were assessed - fly ash agloporit and am-phibolite incl. combinations thereof. Laboratory tests were carried out via determination of basic material properties (density, strength, consistency, dimensional changes etc.) after exposure to extreme temperatures. A substantial part of the research was also study of different cooling conditions - slow and fast (water and air). Selected formulations were subjected to temperatures up to 1200 ° C. In the conclusion is selected several recipes that have been found to be optimal for continuing research on the basis of the results and findings.
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Deterministické a stochastické modely v molekulární a buněčné biologii
Krasnovský, Pavol ; Vejchodský, Tomáš (advisor) ; Klebanov, Lev (referee)
This thesis presents the main methods that are used to model the time evolution of the number of molecules in a cell. Two of the main aims in cell biology are to compute first the transi- tion probability function and second the density of the invariant measure. These two problems imply a number of conditions and hence we also include the ergodic theory and theory of the invariant measure. We use two illustrative examples of the application of the previously mentioned theories. We verify the necessary and sufficient conditions for the computation of the transition probability function and the density of the invariant measure in case of two types of a chemical system. The probability function and the density are then given by a numerical solution to the Fokker-Planck equation in both the dynamic and the stationary case. Furthermore, we compare the obtained solu- tions to the results from the Monte Carlo simulation. We find that the solutions give almost identical results as the Monte Carlo simulation. At the end of this thesis, we formulate and analyze a chemical system represented by a human cell infected by an influenza virus. Given the complexity of the sys- tem, we compute the results using the Monte Carlo method. In addition we define this problem by a stochastic differential equation with random...
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Study of Sterilization Effects Initiated by Dielectric Barriere Discharge
Slámová, Jitka ; Pekárek, Stanislav (referee) ; doc. RNDr. Karol Hensel, Ph.D., oponent (referee) ; Krčma, František (advisor)
The overall goal of the presented dissertation thesis was to study the sterilization efficiency of dielectric barrier discharge operated at atmospheric pressure. The fungi Aspergillus niger, gram-positive bacteria Bacillus subtilis and in some experiments also gram-negative bacteria Escherichia coli were used as a bio-indicator enabling to evaluate the effect of plasma assisted microbial inactivation. The samples of microorganism were placed on paper Whatman 1 or PET foil and exposed to plasma. The plasma was generated in argon, nitrogen, synthetic dry/humid air with frequency up to 10 kHz and plasma power density in the range of 1,2-2,9 W/cm3 (according to the process gas). The influence of process gas, plasma power density, plasma exposition time, type of microorganism and material of the substrate on the sterilization effect of dielectric barrier discharge was evaluated. Furthermore the contribution of each single mechanism (UV radiation, temperature and reactive species) to the sterilization effect of plasma and influence of gas humidity was evaluated. The DBD was analysed by means of optical emission spectroscopy, thermocouple was used to measure temperature during a sterilization process. In order to verify the mechanical damage of the microbial cell or the substrates during the plasma process the samples were studied by scanning electron microscopy. Generally, on the basis of experimental results, at increasing treatment times, the remaining number of spores (CFU) decreased. Similarly at increasing the plasma power input, the sterilization rate increased. When sterilising the spores of A. niger in plasma using different process gasses, the efficiency of plasma sterilization decreased as follows: argon, humid synthetic air, nitrogen and dry synthetic air. The results observed in argon plasma using different microorganism demonstrated that the sensitivity of vegetative cells resp. spores to DBD decreased as follows: A. niger spores, B. subtilis vegetative cells, E. coli vegetative cells and B. subtilis spores. Simultaneously results observed for sterilization of spores and vegetative cells of B. subtilis and A. niger demonstrated that the spores are generally more resistant to plasma than are the corresponding vegetative cells. Combining the results of contribution of each single mechanism, optical emission spectroscopy and inactivation characteristic it was found out that the reactive species significantly contribute to the plasma sterilization in all process gasses. Furthermore the inactivation process can be partly assisted by UV radiation and also the temperature can contribute in limited extent to inactivation process in some gasses. The contribution of UV radiation to the plasma sterilization decreased as follows: nitrogen, argon, dry syntetic air and humid syntetic air. Moreover it was found out that the contribution of each single mechanism can be species dependent, this is due to the different response of microorganism to the unfavorable external conditions. SEM analysis of the substrates prooved the etching actions of the plasma generated in all process gasses on the surface of the PET foil. The several minute plasma exposition of the PET foil resulted in the occurence of the „hole corrosion“ on the PET surface. Contrary to these there were no visible changes observed in the paper structure.
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Past dynamic of alpine treeline ecotone in the eastern part of the Krkonoše Mts.
Jungrová, Alena ; Treml, Václav (advisor) ; Chuman, Tomáš (referee)
4 Abstract The purpose of the diploma thesis is the analysis of changes in the alpine treeline ecotone with focus on the age structure and cover of the Norway spruce (Picea Abies) in the Giant Mountains in the 20th century. The altitudinal position and the tree density of the alpine treeline ecotone is a sensitive indicator which reflects the human impact as well as the climatic and air pollution changes. Methodical approach included the measuring of the age structure of the Norway spruce by using dendrochronology. In addition the changes of the spruce cover were evaluated from a series of aerial photographs dated 1936, (1953) 1964, 1985 and 2002. Those photographs were orthorectified and classified. The age distribution in the majority of the sample locations is irregular with some prominent peaks that are corresponding to the periods of good conditions and dips pointing out to the periods of disturbances. There is an evident peak during the 30s and 40s which is the same period of the increase of average temperatures of the growing season. On the contrary, depression during the 70s and 80s is detected only in the case of closed-canopy forest. The increasing number of trees during the 90s is related to the decreasing air pollution and to the higher average temperature. Relatively young age structure of the...
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Fyzikální vlastnosti medů
Slováček, Robin
The bachelor thesis is focused on the physical and rheological properties of honeys and influences on these properties. Physical properties of honeys are very different depending on chemical compositon on honey, sources of honey, climatic and geographic conditions. Crystallization of honey depends on the content of glucose and frucose. Nectar honey crystallize more rapidly than honeydew honey, because nectar honey has got a higher amount of glucose. The density of honeydew honeys is higher then nectar honey. The higher density of honey have a honeydew honeys, it is about a minerals. The colour of honeys depends on botanic origin, processing method and lenght of storage. Nectar honeys are lighter than honeydew honeys. Electrical conductivity is very important feature, because this feature we can find out the botanic origin of honey. Honeydew honeys have a higher electric conductivity, because they have got a larger amout of minerals. Rheological properties of honeys depends on composition of sugar and botanic origin.Viscosity is a reological properties of honeys which dicreases with increasing temperature.
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