National Repository of Grey Literature 867 records found  1 - 10nextend  jump to record: Search took 0.19 seconds. 

Degradation of organic pollutants in aquatic environment photoinduced by Fe(III)Cit complex: Impact of TiO2
Kolář, Michal ; Jirkovský, Jaromír ; Mailhot, G. ; Bolte, M. ; Krýsa, J.
Iron is the most abundant transition metal on the Earth. It is present in the atmosphere, soils as well as aquatic environments. In the aquatic media, it is often presnt in a form of Fe(III) complexes, especially with polycarbolic acids. The complexes of Fe(III) are highly photosensitive in general.

Preparation and properties of pyroelectric detectors for optoelectronic applications /III/
Novotný, Jan ; Zelinka, Jiří ; Podvalová, Zdislava ; Malina, Václav ; Vávra, Vladimír ; Franc, J. ; Fronc, Václav ; Fronc, Václav
The single crystals of TGS doped with Pt-ions and with L-alanine were grown as in ferroelectric phase as the full-shaped crystals. The growth rate along the axis c of the doped crystals is much higher than in an undoped one. Morphology, domain structure and hysteresis loops were investgated. The effect of the dopant on the growth velocity is explained on the basis of catalytic action of platinum complexes. The pyroelectric detectors were prepared from these materials and their parameters are presented.

Model pro nukleaci dislokací, vrstevných chyb a dvojčat generovaných trhlinou
Beltz, G. E. ; Chang, M. ; Machová, Anna
The contribution presents a continuum model, based on Peierls-Nabarro framework, for generations of dislocations, stacking faults and twins at cracks embedded in bcc iron.

Eating habits of patients with metabolic syndrome
NOVÁČKOVÁ, Anna
Metabolic syndrome (syndrome X, Reaven's syndrome) is frequently occurring disease in Czech Republic. The diagnosis often detected only separated parts of metabolic syndrome which are usually not connected with complex of MS. Medical conditions co-occurred within this syndrome are following: elevated fasting plasma glucose (insulinoresistance), abdominal (central) obesity (women waistline > 88 cm, men waistline > 102 cm), elevated blood pressure, high serum triglycerides (> 1,7 mmol/l), and low high-density cholesterol (HDL) levels (women 1,25 mmol/l, men 1,0 mmol/l). The incidence of MS can be divided into the prevalence of MS itself (this correspond with 30%) and the prevalence of each individual part of MS which correspond with 80% population. The most frequently reasons of MS are so called environmental impacts as e.g. central obesity, insulinoresustance syndrome, fatty liver, systemic inflammation, intestinal alterations, hypertension, hypertriglyceridemia, foetal malnutrition, low basal energetic outcome, sleep apnoea syndrome, changes of gut flora, hyperglycaemia and cumulation of visceral fat. This bachelor´s work is concerned with eating habits, life style and other factors which could be reason of described metabolic syndrome. The aim of this study is evaluation of eating habits and life style of patients suffered from MS before syndrome outbreak, as well as participation of obesity in MS outbreak assessment. Two explorative questions were formulated on the basis of described goals: First research question: Did the MS patients follow principles of healthy eating before syndrome outbreak? Second research question: Does obesity have a significant effect on MS outbreak? Definition and characterization of MS in relation to diet is described in theoretical part of my work as well as explanation for reasons of MS outbreak, descriptions of each separated diseases of MS complex and their treatment. Metabolic syndrome in connection with obesity and its classification into each level is defined inthis part. Obesity treatment together with prevention and treatment of MS are suggested in terminal part of this section. In practical part of work, the results of own research are presented. This section is focused on: 5. evaluation of eating habits before MS outbreak; 6. obesity incidence in MS patients; 7. patient´s life style; 8. the presence of individual diseases participate in MS. Research part of my bachelor´s work is prepared with using of quantitative assessment, which was done by questionnaire investigation in southbohemian and westbohemian region. Research population consists of thirty gender-nonspecific and age various patients diagnosed as having MS. The research questions were focused on mapping of respondent´s eating habits, life style (smoking, movement activity, daily eating portions and breakfast regularity), previous and current illnesses as well as diseases of respondent´s relations. The aim of described investigation was evaluation of obesity, life style and diet participations in MS outbreak. The results did not prove observance of healthy eating principles in MS patients before and after syndrome outbreak, while most of respondents were overweight or obesity. It can be assumed that genetic predispositions play role in MS outbreak. Additionally, very interesting is detected occurrence of MS in many individuals younger then forty years old. The present work extended the knowledge about risk factors of MS outbreak together with eating habits, obesity and MS outbreak connections. When reasons of MS seem to be more clear, it is easier to establish new more effective prevention. On the basis of the results, it can be arranged diet suggestions useable as effective prevention of MS outbreak.

Securitization- A critical assessment in the light of the financial crisis
Marinova, Milena ; Krupová, Lenka (advisor) ; Marek, Petr (referee) ; Doubravský, Jiří (referee)
My dissertation thesis provides a comprehensive analysis of the principles of securitization techniques, of their attendant shortcomings, their regulatory treatment and the recent proposals for reducing complexity in accounting standards with relevance for securitizations. The explosion of securitization and related innovative credit risk transfer products largely expanded the magnitude and diversity of issuers, investors and securities. With this expansion numerous market participants began to wrongly believe that risk was not only shared more widely, but also that it disappeared from the system altogether. The application, or to be more precise, the misapplication of securitization in the mortgage market had fatal consequences for the financial sector worldwide. Before securitization, sub-prime mortgage lenders retained the loans that they originated on their balance sheets and therefore cared about their credit quality. Securitization techniques and related innovative financial instruments enabled the export of sub-prime mortgage structural problems from the United States globe-wide via the financial intermediaries. More over, securitization techniques and related credit risk transfer products enabled single banks to reduce their individual risk while at the same time transferred new and greater risks to the financial system. Meanwhile a lot was written on the causes for the recent financial crisis. In most cases inadequate ratings provided by the credit rating agencies and different principal agent problems were addressed. I present both for completeness in my work. However, I argue that not only the credit rating agencies are to blame for the inadequate reflection of securitization and related financial innovations and subsequently for the financial turmoil. The international and national financial supervisors in fact supported the credit rating agencies to further establish their businesses. What turned obvious during and after the financial turmoil started mid-2007 is that financial regulation failed to reach its main goal - ensuring stability of the financial system. It failed despite of the "regulatory achievements within Basel II" elaborated over the past ten years. In particular, securitization and related credit risk transfer products were not adequately treated in Basel II. Securitization-related products such as Credit Derivatives on Securitization Underlyings and numerous other complex financial innovations, as presented in my thesis, were not even thought of in Basel II. In fact, Basel II turned to do little to make the financial system more resilient. The need for further revisions in banking regulation is currently more than obvious. Furthermore, it is time to ask if the developments in Basel II are the right way to address the current risks within the financial system and hence if Basel II is the right way of banking regulation and supervision altogether. With the development of both Basel Accords (Basel I and Basel II) capital ratios became the center of banking regulation. However, capital ratios are obviously not sufficient as a measure for a systemic financial stability. These questions arise at least when financial stability and soundness are still the intended objectives and believed to be ensured through Basel II. My merits in this dissertation work root in the multi-facet analysis of securitization techniques that I provide. Up to date a comparable analysis of securitization techniques which addresses the wide spectrum of securitizations' issues - such as (i) their treatment and the related attendant flaws within the regulatory framework Basel II, (ii) the various microeconomic deficiencies related to securitizations, and (iii) the implicit macroeconomic threads of exporting credit risk and de-balancing financial stability through securitization techniques - has not been provided in the comprehensive way I built up my analysis. As a basis for my analysis, I provide a new classification of the characteristics of securitization techniques which were pre-crisis wrongly perceived as benefits. I analyze the reasons for the turmoil in the financial markets in their interplay and complexity and consider securitization techniques as a key driver for the financial crisis. I comprehensively criticize the current regulatory treatment. I present in detail why the recent financial crisis should be considered a clear regulatory failure due to the up to date short-sightedness of financial regulation. Through providing partial solutions and professional author's assessment of selected regulatory and accounting changes to securitizations I deliver an expert's contribution to the topic. My conclusions are that securitization markets, as they have been operating until today, brought a negative net macroeconomic effect which has been largely damaging to the global economy. I argue that international and national financial supervisors established an inadequate framework for financial regulation and supervision, and among other failures, even supported credit rating agencies to further establish their businesses. Further on, I show that early warning indicators of systemic risk in the financial sector and signs of the coming turmoil were irresponsibly ignored at the time they were perceived. What turned obvious during and after the recent financial turmoil is that capital regulation failed to reach its main goal -- ensuring stability of the financial system. In particular, securitization and related credit risk transfer products were adequately treated neither in Basel I nor in Basel II. Finally, I conclude that capital ratios as established with the development of both Basel Accords are not sufficient as a central measure for banking regulation and ensuring systemic financial stability.

Crystallographic study of the iron-regulated outer membrane lipoprotein (FrpD) from Neisseria meningitidis
SVIRIDOVA, Ekaterina
Neisseria meningitidis (N. meningitidis) is a Gram-negative commensal bacterium colonizing nasopharynx of about 10 % of healthy individuals, which can cause invasive diseases, such sepsis and meningitis, upon occasional penetration into bloodstream. Pathogenesis of N. meningitidis appears to be directly related to conditions of limited iron availability. Under these conditions two proteins of unknown function: FrpC and FrpD, are synthesized. FrpD is a highly conserved lipoprotein of N. meningitidis anchored to the bacterial outer membrane. It is known that FrpD tightly binds the FrpC protein, which belongs to the Repeat-in-Toxin (RTX) protein family and may act as bacterial exotoxin. However, the mechanism of FrpD-FrpC interaction and the exact function of this complex are unknown due to the absence of structural information on these proteins. Therefore, we set out to determine the structure of FrpD and provide insights into its interaction mechanism with FrpC and structure-functional relationships of these two proteins. We determined the first crystal and solution structures of the FrpD protein. We found that atomic structures of FrpD reveal a novel protein fold. We uncovered the structure-function relationships underlying the mechanism of interaction between the FrpD and FrpC proteins and tested the putative function of the FrpD-FrpC1-414 complex in vitro. Finally, we proposed the putative function of the FrpD-FrpC1-414 complex as a new minor adhesin of N. meningitidis, which mediates the bacterial adhesion to the host epithelial cells and facilitate the colonization. Our work constitutes the first step in clarifying the molecular basis of the FrpD-FrpC interaction and sets the base for further investigation of the role of FrpD and FrpC in the virulence mechanism of N. meningitidis.

The Physical Modelling of the Flow above the Complex Terrain
Houbová, Eva
Článek popisuje řešení jednoho případu znečišťování ovzduší-v oblasti s komplikovaným terénem Jablonného nad Orlicí.Problém byl modelován fyzikálně.Po stručné zmínce o řešení pomocí matematického modelování následuje podrobnější popis modelování fyzikálního, v aerodynamickém tunelu.Je uveden přehled základních rovnic pro proudění tekutiny a podmínek podobnosti.Při fyzikální simulaci (1:1000) byl vyšetřován vliv dvou bodových zdrojů SO2.Byla použita Townsendova hypotéza o nezávislosti na Reynoldsově čísle. Šíření emisí se zkoumalo v aerodynamickém tunelu (při ÚT AV ČR): kvalitativně laserovým nožem a kvantitativně za použití analyzátoru IREX (ve spolupráci s Ústavem pro hydrodynamiku).Modelovaná atmosféra měla neutrální teplotní zvrstvení.Z hodnot přízemních koncentrací naměřených na modelu byly určeny přízemní koncentrace reálné. Nejvyšší míra znečištění byla prokázána na sídlišti.Lze předpokládat, že se emisní situace v Jablonném nad Orlicí zlepší,jestliže se podaří ve větším rozsahu rozšiřovat vytápění města plynem.

Quantitative modelling of effect of transverse-axial tubular system on electrical activity of cardiac cells: development of model
Pásek, Michal ; Christé, G. ; Šimurda, J.
The transverse-axial tubular system (TAT-system) of cardiac muscle is a structure that allows rapid propagation of excitation into the cell interior. As suggested in many recent experimental works, it could have a significant effect on cardiac cell function induced by the accumulation or the depletion of ions in restricted tubular space. In our previous work [27], the basic properties of TAT-system were formulated and preliminary simulations characterizing its effect on cellular electrical activity realised. In this article, we describe the design of a more complex model of ventricular myocyte based mostly on data from guinea pig. The model integrates the description of electrical activity of surface and tubular membranes with the detailed description of mechanisms controlling the intracellular and tubular ion concentrations.

The use of (nano)oxides for metal and metalloid stabilization in contaminated soils
Michálková, Zuzana ; Komárek, Michael (advisor) ; Luke, Luke (referee)
The main objective of the thesis was to evaluate the potential of selected Mn and Fe (nano)oxides for the stabilization of metals and metalloids in contaminated soils. The research was focused basically on three materials - commercial nanomaghemite (Fe III), nanomagnetite (Fe II,III) and a synthetic amorphous Mn oxide (AMO). The main aim of the work was to provide a complex view on the chosen stabilizing amendments regarding not just their direct influence on contaminants mobility and stabilization mechanisms, but also their stability and alterations in soil conditions together with influence on soil microorganisms and higher plants. Firstly, adsorption properties of the tested materials towards Cd, Cu, Pb and As were investigated. In this context, the most effective material showed to be the AMO reaching one to two orders of magnitude higher adsorption capacities than Fe III and Fe II,III under given experimental conditions. Interestingly, the rate of As(V) adsorption onto AMO was increasing with increasing pH as a result of high pHzpc of the AMO (8.1) and significant dissolution of this phase at lower pH values. As a next step, the influence of (nano)oxides on metal(loid)s mobility and other physico-chemical soil characteristics after application to contaminated soil was examined. Again, the AMO proved to be the most efficient in reducing mobile pools of Cd, Cu, Pb, Zn and As. On the other hand, Fe III and Fe II,III addition had generally less significant effects on contaminants mobility. AMO application further resulted in an increase of soil pH connected with AMO dissolution and unwanted decomposition of soil organic matter. When (nano)oxides alterations in soil conditions were observed, MnCO3 coatings were identified on AMO surface while no significant changes were recorded for Fe III and Fe II,III. As the MnCO3 formation was connected with increased AMO stability, AMO particles synthetically covered with MnCO3 coating (denoted as SM AMO) were prepared. Although the SM-AMO had a lower mass loss in soil than pure AMO, the stabilizing efficiency was almost the same for both materials. The differences in surface composition of both materials were decreasing with time as MnCO3 naturally precipitated on the AMO surface in soils while the SM AMO coating was gradually dissolving. When investigating the effect on soil microbiota, AMO efficiently promoted soil microbial activity while no significant changes were observed in the case of Fe III and Fe II,III. The AMO was also able to reduce the uptake of Cd, Pb and Zn by sunflower (Helianthus annuus L.), eliminate Zn phytotoxicity symptoms and increase biomass yield. On the other hand, toxic levels of Mn released from the AMO in an acidic soil were found in sunflower tissues. AMO application is thus recommended for contaminated neutral or slightly alkaline pH with a higher cation exchange capacity in order to avoid unwanted release of Mn. Finally, various types of AMO-biochar composite sorbents were recently prepared and field experiment focused on stabilization of Cd, Pb, Zn and As using studied materials is currently under preparation. The combined results from the thesis highlight the importance of a complex experimental approach dealing with all parts of the contaminated soil environment in order to obtain complete information about the efficiency and usefulness of any newly developed stabilizing amendment.

Numerical modelling of pollution dispersion in complex terrain
Bodnár, T. ; Kozel, K. ; Fraunié, P. ; Jaňour, Zbyněk
Amathematical model for prediction of flow and pollution dispersion in ABL is developed. A numerical method is proposed for the solution of the governing system of PDE. The method is based on finite-difference semi-implicit discretization scheme. structured boundary-fitted mesh. Some results od simple numerical tests are presented and discussed.