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Study of proper and improper microwave dielectric losses by means of teraherz and infrared spectroscopy
Tkáč, Ondřej ; Kamba, Stanislav (advisor) ; Petzelt, Jan (referee)
Title: Study ol"proper and improper microwave dielectric tosses by means of tcrahcrz and infrared speetroseopy Author: Ondfej Tkac Department: Department of Dielectrics. Institute of Physics, Academy of Sciences of C/ech Republic Supervisor: RNDr. Slanislav Kamba.C'Sc.. Na Slovance 2. Prague 8 Supervisor's e-mail adress: kambawT/u.c/ Abstract: In the llrst part of this thesis there is described relevant theory, especially we pay our attention to the principles of infrared speetroseopy and fitting models, then to the explanation of the terms proper and improper dielectric losses and we also discuss dielectrics and ferroelectrics. By means of Fourier transform infrared speetroseopy we measured infrared spectra at room temperature in the range of 30 - 3000 em"1. We lilted the spectra and then we extrapolated the final complex permit!vity into the microwave range. This enabled us to estimate the proportion of improper dielectric losses on total microwave losses. By the ceramic SiVxPlxCeVfinO-^ (.\0 to 9) we studied the impact of amount of lead on dielectric properties. We found out that the substitution of strontium with lead causes the increase of permitivity up lo several thousands and forces ferroelectric transition for x>2. With perovskitc Ca/n, jNb^ :,-xVx(.)1 (.v=0 to 0,01) we examined the inlluence of...
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Measurement of the membrane potential using ion-selective electrode sensitive to tetraphenylphosphonium
Lábajová, Anna ; Kofránek, Jiří (advisor) ; Sigler, Karel (referee) ; Plášek, Jaromír (referee)
103 ABSTRACT The computerized device for membrane potential measurement using the tetraphenylphosphonium-selective electrode was constructed. Signal acquisition, processing and data storage were realized by MATLAB/Simulink software. The selective membrane was optimized incorporating TPP+ TPB- precipitate into the membrane. The electrode had a Nernstian response from 3.10-6 M TPP+ . The TPP+ TPB- precipitate was later replaced by sodium tetrakis[3,5-bis(1,1,1,3,3,3-hexafluoro-2- methoxy-2-propyl)phenyl]borate (NaHFPB). The electrode with incorporated NaHFPB had a Nernstian response from 1.10-6 M TPP+ and had better sensitivity than commercially available electrodes. The values of selectivity coefficients for K+ , Na+ , Ca2+ and Mg2+ were calculated. The device was used for mitochondrial membrane potential measurement of isolated mitochondria and for evaluating the respiratory chain function of digitonin- permeabilized cells (hepatocytes, HeLa G, BSC-40 and control transmitochondrial cybrids). This method was used also for monitoring the mitochondrial permeability transition pore (MPTP) function of isolated mitochondria and permeabilized hepatocytes. MPTP opening was induced by high calcium concentration and the action of calcium was enhanced by pro-oxidant tert-butyl hydroperoxide (t-BHP). This...
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The Criteria for Granting of Care of Elderly People.
JANOŠŤÁKOVÁ, Iveta
Modern conception of social care is adjusted by Act No. 108/2006 Col., on social services. It includes a description of conditions of providing assistance and support to individuals in adverse social situation through social services, particularly by a new benefit ? care benefit. This is used by people who are limited by their health condition in normal life. The new conception philosophy is based on the fact that people using the care benefit, dependent on assistance of other individuals are completely free to decide who and how will provide them with the assistance. Its subsequent use has to lead people to activity, support of development of their independence and motivation, to prevent worsening of their adverse social situation. The purpose of the care benefit is to keep the ill person alive as long as possible and to live with dignity in his/her natural environment. The care is provided either by close persons (family) or by social service providers from government or non-government organizations. The aim of the thesis was to map the criteria in the field of the method of dependence assessment for granting care benefit to seniors over 65 years of age in České Budějovice district, who were assessed in 2012 in so-called transitive period according to both the regulations. The theoretical part defines the terms senior, aging process and informs on social factors leading to human life extension. It describes development of social work in the Czech Republic and establishment of the Social Service Act effective from 1 January 2007, the main idea of which was modification of the role of the state as the social care provider, and active involvement of a citizen as the benefit receiver. The next part of the thesis describes criteria of care benefit granting according to the original regulations valid from 1/1/2007. It is granted in four levels corresponding to different amounts with regards to age and number of acts (36 evaluated). Ability to cope with individual acts of care about oneself and self-sufficiency are evaluated in assessment of dependence degree for the care benefit purposes. The Social Service Act has been amended several times; a substantial change of the criteria for granting the benefit came on 1/1/2012, when Act No. 366/2011 Col., modifying certain provisions of the Social Service Act, became effective. In the new assessment of dependence degree the ability of a person to cope with 10 basic life needs is evaluated. Two hypotheses were tested in the practical part of the thesis upon the set goals: 1. Higher dependence degree is recognized in assessment of dependence degree in seniors according to the new criteria. 2. Lower number of evaluated acts in assessment of dependence degree corresponds with objectivization of health condition of the assessed person. The research was performed by means of quantitative method, namely data content analysis and the obtained data were statistically processed by categorical data analysis, Pearson?s correlation coefficient and contingency tables. Data from the statistics of the Czech Social Security Administration, its local workplaces and accessible materials of the Ministry of Labour and Social Affairs of the CR in 2007 and 2012 were used for the research. After analysis and evaluation of the necessary information we found that the first hypothesis was not confirmed; higher degree is not recognized in assessment of dependence degree in seniors. The second hypothesis was confirmed, the lower number of assessed acts correspond with objectivization of health condition. In the conclusion we observe that the new criteria for assessment of dependence degree for the purpose of granting the care benefit do not lead to recognition of higher dependence degree.
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Fracture behaviour of welds made of pearlitic and bainitic steel
Dlouhý, Ivo ; Holzmann, Miloslav ; Zbořil, J.
The paper is focused on microstructure evaluations, hardness and fracture behaviour analyses of welded joint made from newly developed cast bainitic Lo8CrNiMo steel and pearlitic rail steel of the type UIC 900A. Dynamic fracture toughness was evaluated based on data from precracked Charpy type specimens loaded by means of instrumented impact tester. The lowest dynamic fracture toughness values and consequently the higher risk of brittle fracture possesses the pearlitic steel UIC 900A and its HAZ. At application temperature range this steel is on lower shelf of ductile to brittle transition, the tempering in HAZ didnŽt affect the toughness substantially. The cast bainitic steel in joint is typical by two times higher toughness values comparing to pearlitic one, in HAZ further toughness increase may be expected. The weld zone itself is characterised by high scatter of toughness data, nevertheless, all the values are above the scatter band characterising the pearlitic steel.
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Biophysical studies of membrane transport proteins from Nramp/MntH family and their function
Ňuňuková, Věra
Three synthetic peptides corresponding to transmembrane segments TMS1, TMS3 and TMS6 of secondary-active transporter MntH from Escherichia coli were used as a suitable alternative model enabling to study TMS structure, TMS interaction with membranes, TMS mutual interaction and also function of MntH. The secondary structure of the peptides was estimated in different environments using circular dichroism spectroscopy. These peptides interacted with and adopted helical conformation in lipid membranes. Electrophysiological experiments demonstrated that individual TMS were able under certain conditions to form ion channels in model biological membranes. Electrophysiological properties of these weakly cation-selective ion channels were strongly dependent on surrounding pH. Manganese ion, as a physiological substrate of MntH, enhanced the conductivity of TMS1 and TMS6 channels, influenced the transition between closed and open states and affected the conformation of all studied peptides. For TMS3 Mn2+ was crucial for formation of ion channels. It was shown that a single functionally important TMS can retain some of the functional properties of the full-length protein. These findings can contribute to understanding of structure-function relationship at the molecular level. However, it remains unclear to...
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The study of the changes of hepatocyte energy metabolism: the effect of oxidative stress and triiodthyronine
Endlicher, René ; Červinková, Zuzana (advisor) ; Kalous, Martin (referee) ; Rauchová, Hana (referee)
Changes of energy metabolism of hepatocytes: The effect of oxidative stress and triiodothyronine Liver is a vital organ performing numerous essential functions. Due to its position in the blood circulation, liver is the first organ incessantly exposed to a great number of toxic substances. Respiratory chain located in mitochondria is a frequent target of toxic action of these substances. There are various mechanisms that participate in hepatocyte damage, nevertheless the most important mechanism of hepatotoxic effect is oxidative stress induced by increased production of free radicals. Impact of oxidative stress on hepatocytes is very complex and still not fully elucidated. The aim of my thesis was to investigate the effect of oxidative stress on energy metabolism of rat hepatocytes using isolated hepatocytes and isolated mitochondria. We evaluated the effect of oxidative stress on the activity of mitochondrial enzymes and function of mitochondrial permeability transition pore (MPTP), respectively. Opening of this pore induces activation of apoptotic and necrotic processes. Our results document selective action of oxidative stress on the activity of various mitochondrial enzymes. Tert-butylhydroperoxide (t-BHP) causes significant inhibition of NADH-dependent substrates, while oxidation of...
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The OCA Theory and its application to tranzition economies
Stehlík, Petr ; Chytilová, Helena (advisor) ; Chytil, Zdeněk (referee)
The goal of this bachelor paper is to answer a question, which transition economy best fulfills the optimum currency area criteria in relation to the European Monetary Union. The first part deals with history of the OCA theory. I focus on important papers (Mundell, Kenen, McKinnon etc.), which gives proper insight to summarize the optimum currency area criteria. These criteria are the background for analytical part of the thesis. I analyse these criteria separately. According to analysis I assign coefficients for each kriteria and for each economy. In the conclusion I compare transition economies and we try to find out, which economy best fulfills the optimum currency area criteria in relation to the EMU.
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Ammonia production by colonies of mutants and aging of wrinkled colonies of Saccharomyces cerevisiae
Nedbálková, Jana ; Heidingsfeld, Olga (referee) ; Janderová, Blanka (advisor)
Production of ammonia by the colonies of mutants and aging of wrinkled colonies of Saccharomyces cerevisiae The aim of this diploma thesis is to observe the development, respectively the aging of cells in yeast colonies Saccharomyces cerevisiae. Yeast cells S. cerevisiea form multicellular organized structures on a solid substrate, i.e. colonies, which the intercellular interactions occur in. These interactions influence forming, morphology and aging of yeast colonies. This diploma thesis is focused partly on the changes in ammonia production by giant colonies of deletion mutants and partly on the aging of colonies with the wrinkled morphology. I characterized mutant strains of S. cerevisiae with the deletion in RTG1, RTG2, RTG3, FIS1, CIT2 genes. Their products play an important role in the colony development. The transcription of these genes changes during the transition from the acidic to alkali phase during developmental process of the colonies. I have found out that the ammonium production rate was in accordance with the results of the alkalization in giant colonies surroundings and mentioned mutants derived from the BY strain has been producing ammonia since the 15th day. The rate of the ammonia production by rtg3∆ strain was comparable to the parental strain. Compared to parental strain, lower...
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Study of the valenčního belt of transition metals and their alloys
Škoda, Michal
Nazev prace: Studium valencniho pdsu prechodovych kovu ajejich slitin Autor: Michal Skoda Katedra (ustav): Katedra elektroniky a vakuove fyziky Vedouci diplomove prace: Prof. RNDr. Vladimir Matolin, DrSc. E-mail vedouciho: matolin@mbox.troja.mff.cuni.cz Abstrakt: Prace se zabyvd studiem bimetalickeho systemu Ce/Pd(lll) metodami fotoelektronove spektroskopie (PES). Vysledky ziskane metodou rezonancni fotoelektronove spektroskopie (RPES) ukazuji, ze zmena chemickeho stavu systemu je zfejme doprovdzena vyznamnou modifikaci pdsove struktury atomu sytemu, kterd se projevuje dramatickymi zmenami obzvldste ve valencnim pdsu. Metoda RPES se prokdzala byt velmi mocnym ndslrojem ke studiu elekironove struktury valencniho pdsu. Klicova slova:^P5, SRPES, RPES, Pd, Ce Title: Valence band study of transition metals and their alloys Author: Michal Skoda Department: Department of Electronics and Vacuum Physics Supervisor: Prof. RNDr. Vladimir Matolin, DrSc. Supervisor's e-mail address: matolin@mbox.troja.mjf.cuni.cz Abstract: The work deals with study of bimetallic system Ce/Pd(lll) by photoelectron spectroscopy method (PES). Its investigation by resonant photoelectron spectroscopy (RPES) showed, that the chemical state modifications of the system induce significant modifications in the band structure of its atoms...
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Monolayers of platinum nanoparticles prepared by dip-coating
Černohorský, Ondřej ; Grym, Jan ; Yatskiv, Roman ; Pham, V.H. ; Hudry, D. ; Dickerson, J.H.
Platinum is a transition metal known for its catalytic properties, which are further enhanced when employed in a nanoparticle form. We have recently shown that a monolayer of Pt nanoparticles deposited on semiconductor substrates forms high quality Schottky diodes, which were used in sensitive hydrogen sensors with a detection limit of 1 ppm of H-2 in N-2. Preparation of ordered monolayers of Pt nanoparticles is essential for the understanding of the behaviour of such an interface. To obtain a hexagonal closed-packed nanoparticle array, we prepared Pt nanoparticles stabilized by oleylamine and oleic acid with a narrow size distribution and uniform shapes. A monolayer prepared by dip-coating of Si substrate in the suspension containing Pt nanoparticles showed hexagonal arrangement within separate domains with the surface coverage up to 90%. The increase of the surface coverage with increasing withdrawal speed of the dip-coating process was observed
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