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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Semiramide riconosciuta G. M. Rutiniho (Praha 1752) / Semiramide riconosciuta by G. M. Rutini (Prague 1752)

Pincová, Kateřina January 2017 (has links)
Setting a very famous Metastasio's libreto Semiramide riconosciuta to music in Prague in 1752, Giovanni Marco Rutini has ranked among the best composers of his time. The aim of this thesis is to explore the process of this production coming to light: the influence of changes in the original libretto in the beginning to the impact of music later. Researching the context of the Prague theatre productions in the 1750s, we were further able to make some suggestions about the reasons of these changes/interpretations. Studying the dramaturgical level of this composition in the first place, we were using comparison and stylistic analytical methods which showed Rutini as a very creative composer with a sense of dramatical situations and a characterization skills. Key words: Giovanni Marco Rutini, Semiramide riconosciuta, Pietro Metastasio, Giovanni Battista Locatelli, Christoph Willibald Gluck, dramaturgy of opera, musical analysis
52

Vybrané p-prvky v učivu chemie na střední škole / Selected elements of p-block in education of chemistry at secondary schools

Valášková, Veronika January 2010 (has links)
The main subject of this thesis is a practical elaboration of the subject "Boron, Carbon and Nitrogen Group of the p-block elements" in form of presentations created using the Microsoft PowerPoint program. The presentations are designed to be used in practice, during the education of chemistry at secondary schools. The thesis also contains additional comments for teachers and an analysis of curricular documents and selected textbooks. It is elaborated in accordance with the RVP G programme.
53

Complexes binucléaires organofers électro-actifs à pont fonctionnel pour l'électronique moléculaire / Binuclear organoiron redox complexes with a functionnal bridge for molecular electronics

Justaud, Frédéric 15 April 2013 (has links)
Ce manuscrit de thèse décrit la conception, l’élaboration et l’étude de complexes organofers électro-actifs dans lesquels deux unités terminales Cp*(dppe)FeII/III sont reliés par un pont fonctionnel. Dans le premier chapitre, nous avons présenté une réaction à la fois originale et efficace catalysée par le Pd(0) qui permet d’accèder à la [5,5’-{(Cp*(dppe)Fe–C≡C}2-(μ-2,2’-bipy)]. Le deuxième chapitre porte sur la présentation d’une voie de synthèse rapide et efficace du métallo-ligand [6,6’-{Cp*(dppe)Fe–C≡C}2-(μ-2,2’-bipy)]. Le troisième chapitre de ce mémoire est consacré à l’utilisation du ligand 1’,1’’’-bis(éthynyle)biferrocényle comme pont entre deux terminaisons électroactives Cp*(dppe)FeII/III. L’espaceur électro-actif joue le rôle de relais moléculaire favorisant le transfert électronique d’une terminaison à l’autre par sauts successifs. Afin d’ajuster les potentiels redox des terminaisons par rapport à ceux du biferrocényle, les terminaisons Cp(PPh3)2M (M = Ru, Os) ont également été utilisées pour substituer un ou deux sites organofers. Le chapitre quatre est dédié aux travaux réalisés sur le système hybride Cp*(dppe)Fe-C≡C-TTMe3. Dans cette molécule, le site Cp*(dppe)FeII/III interagit à travers le pont acétylure avec le fragment tétrathiafulvalényle. La nouvelle molécule est stable sous trois degrés d’oxydation. L’espèce monocationique se comporte comme un composé à valence mixte de classe II et le couplage électronique entre les deux électrophores a été déterminé (Hab = 320 cm-1). Dans le cinquième et dernier chapitre nous mettrons à profit la découverte d’une réaction d’activation de la liaison C-H du groupement méthyle situé sur le même cycle du TTF et de l’acétylure de fer dans le composé [Cp*(dppe)Fe-C≡C-TTMe3](PF6)3. Cette réaction permet la synthèse du complexe moléculaire multifonctionnel [Cp*(dppe)Fe=C=C=TTFMe2=CH-CH=TTFMe2=C=C=Fe(dppe)Cp*][PF6]2 avec de très bon rendement. Les propriétés physicochimiques de ce nouveau complexe analysées avec le support de la chimie quantique permettent de révéler les caractéristiques originales de ce composé inédit. / This thesis highlights the conception, synthesis and studies of redox-active organoiron complexes in which the two termini Cp*(dppe)FeII/III are linked by a functional bridge. In chapter I, an original and efficient synthetic Pd(0) catalysed homocoupling procedure is reported involving mononuclear organoiron(II) intermediates allowing us to isolate [5,5’-{Cp*(dppe)Fe–C≡C}2-(μ-2,2’-bipy)]. In chapter II, a rapid and efficient synthetic access to the redox-active metallo-ligand [6,6’-{cp*(dppe)Fe–C≡C}2-(μ-2,2’-bipy)] is described. In chapter III, the synthesis and properties of a series of complexes containing bis(ethynyl)biferrocene as a bridge between different redoxactive groups is pointed out. The redox bridge acts as a molecular relay for the electronic exchange between the termini via an electron hopping pathway. In order to tune the redox potential compared with those of biferrocene, one or two organoiron groups have been substituted by the Cp(PPh3)2M (M = Ru, Os) groups. In chapter IV, works are dedicated to the hybrid system Cp*(dppe)Fe-C≡C-TTMe3. In this molecule, electronic interactions take place between the Cp*(dppe)FeII/III center and the tetrathiafulvalene core through the ethynyl bridge. The new molecule is stable under three redox states. The mono-oxidized species behaves as a mixed valence species with an electronic coupling Hab = 320 cm-1 between the two electrophores. In the fifth and final chapter, the discovery of a CH bond activation of a methyl group located on the same cycle of the TTF core and the iron acetylide for the compound [Cp*(dppe)Fe-C≡C-TTMe3](PF6)3 is reported. This new reaction allows the synthesis of the multicomponent molecule [Cp*(dppe)Fe=C=C=TTFMe2=CH-CH=TTFMe2=C=C=Fe(dppe)Cp*][PF6]2 in good yield. The resulting device displays specific properties analysed with the support of the quantum chemistry.
54

X-ray characterization of PaPheOH, a bacterial phenylalanine hydroxylase

Ekström, Fredrik January 2003 (has links)
<p>Many human diseases are associated with the malfunction of enzymes in the aromatic amino acid hydroxylase family, e.g. phenylketonuria (PKU), hyperphenylalaninemia (HPA), schizophrenia and Parkinson's disease. The family of aromatic aminoacid hydroxylases comprises the enzymes phenylalanine hydroxylase (PheOH), tyrosine hydroxylase (TyrOH) and tryptophane hydroxylase (TrpOH). These enzymes require the cofactor (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin (BH4) and atomic oxygen. In eukaryotes, the aromatic amino acid hydroxylases share the same organization with a N-terminal regulatory domain, a central catalytic domain and a C-terminal tetramerization domain. Aromatic amino acid hydroxylases that correspond to the core catalytic domain of the eukaryotic enzymes are found in bacteria. The main focus of this thesis is the structural characterization of a phenylalanine hydroxylase from the bacterium Pseudomonas aeruginosa (PaPheOH). </p><p>To initiate the structural characterization, the active site environment was investigated with X-ray absorption spectroscopy (XAS). The experimental data support a model where the active site iron is coordinated by four oxygen atoms and two nitrogen atoms. We suggest that two water molecules, His121, His126 and Glu166 coordinates the active site iron. In this model, Glu166 provides two of the oxygen atoms in a bidentate binding geometry. EXAFS and XANES studies indicate that structural rearrangements are induced in the second and third coordination shells in samples of PaPheOH with BH4 and/or L-Phe. </p><p>The 1.6 Å X-ray structure of PaPheOH shows a catalytic core that is composed of helices and strands in a bowl-like arrangement. The iron is octahedrally coordinated, by two water molecules and the evolutionary conserved His121, His126 and Glu166 that coordinates the iron with bidentate geometry. The pterin binding loop of PaPheOH (residue 81-86) adopts a conformation that is displaced by 5-6 Å from the expected pterin binding site. Consistent with the unfavourable position of the pterin binding loop is the observation that PaPheOH has a low specific activity compared to the enzymes from human and Chromobacterium violaceum. </p><p>The second part of this thesis focus on the crystallization and structure determination of the actin binding domain of a-actinin (ABD). a-Actinin is located in the Z-disc of skeletal muscle were it crosslinks actin filaments to the filamentous protein titin. The ABD domain of a-actinin crystallizes in space group P21 with four molecules in the asymmetric unit. The structure of the ABD domain has been solved to a d-spacing of 2.0 Å. The two CH-domains of ABD is composed of 5 a-helices each. The a-helices fold into a closed compact conformation with extensive intramolecular contacts between the two domains.</p>
55

Forecast Performance Between SARIMA and SETAR Models: An Application to Ghana Inflation Rate

AIDOO, ERIC January 2011 (has links)
In recent years, many research works such as Tiao and Tsay (1994), Stock and Watson (1999), Chen et al. (2001), Clements and Jeremy (2001), Marcellino (2002), Laurini and Vieira (2005) and others have described the dynamic features of many macroeconomic variables as nonlinear. Using the approach of Keenan (1985) and Tsay (1989) this study shown that Ghana inflation rates from January 1980 to December 2009 follow a threshold nonlinear process.  In order to take into account the nonlinearity in the inflation rates we then apply a two regime nonlinear SETAR model to the inflation rates and then study both in-sample and out-of-sample forecast performance of this model by comparing it with the linear SARIMA model. Based on the in-sample forecast assessment from the linear SARIMA and the nonlinear SETAR models, the forecast measure MAE and RMSE suggest that the nonlinear SETAR model outperform the linear SARIMA model. Also using multi-step-ahead forecast method we predicted and compared the out-of-sample forecast of the linear SARIMA and the nonlinear SETAR models over the forecast horizon of 12 months during the period of 2010:1 to 2010:12. From the results as suggested by MAE and RMSE, the forecast performance of the nonlinear SETAR models is superior to that of the linear SARIMA model in forecasting Ghana inflation rates. Thought the nonlinear SETAR model is superior to the SARIMA model according to MAE and RMSE measure but using Diebold-Mariano test, we found no significant difference in their forecast accuracy for both in-sample and out-of-sample.
56

X-ray characterization of PaPheOH, a bacterial phenylalanine hydroxylase

Ekström, Fredrik January 2003 (has links)
Many human diseases are associated with the malfunction of enzymes in the aromatic amino acid hydroxylase family, e.g. phenylketonuria (PKU), hyperphenylalaninemia (HPA), schizophrenia and Parkinson's disease. The family of aromatic aminoacid hydroxylases comprises the enzymes phenylalanine hydroxylase (PheOH), tyrosine hydroxylase (TyrOH) and tryptophane hydroxylase (TrpOH). These enzymes require the cofactor (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin (BH4) and atomic oxygen. In eukaryotes, the aromatic amino acid hydroxylases share the same organization with a N-terminal regulatory domain, a central catalytic domain and a C-terminal tetramerization domain. Aromatic amino acid hydroxylases that correspond to the core catalytic domain of the eukaryotic enzymes are found in bacteria. The main focus of this thesis is the structural characterization of a phenylalanine hydroxylase from the bacterium Pseudomonas aeruginosa (PaPheOH). To initiate the structural characterization, the active site environment was investigated with X-ray absorption spectroscopy (XAS). The experimental data support a model where the active site iron is coordinated by four oxygen atoms and two nitrogen atoms. We suggest that two water molecules, His121, His126 and Glu166 coordinates the active site iron. In this model, Glu166 provides two of the oxygen atoms in a bidentate binding geometry. EXAFS and XANES studies indicate that structural rearrangements are induced in the second and third coordination shells in samples of PaPheOH with BH4 and/or L-Phe. The 1.6 Å X-ray structure of PaPheOH shows a catalytic core that is composed of helices and strands in a bowl-like arrangement. The iron is octahedrally coordinated, by two water molecules and the evolutionary conserved His121, His126 and Glu166 that coordinates the iron with bidentate geometry. The pterin binding loop of PaPheOH (residue 81-86) adopts a conformation that is displaced by 5-6 Å from the expected pterin binding site. Consistent with the unfavourable position of the pterin binding loop is the observation that PaPheOH has a low specific activity compared to the enzymes from human and Chromobacterium violaceum. The second part of this thesis focus on the crystallization and structure determination of the actin binding domain of a-actinin (ABD). a-Actinin is located in the Z-disc of skeletal muscle were it crosslinks actin filaments to the filamentous protein titin. The ABD domain of a-actinin crystallizes in space group P21 with four molecules in the asymmetric unit. The structure of the ABD domain has been solved to a d-spacing of 2.0 Å. The two CH-domains of ABD is composed of 5 a-helices each. The a-helices fold into a closed compact conformation with extensive intramolecular contacts between the two domains.
57

Synthesis and Fluorescence Properties of Anthracene Derivatives and their Metal Complexes

Finkelmeier, Nils 20 June 2013 (has links)
No description available.
58

Modeling and analysis of chemiluminescence sensing for syngas, methane and jet-A combustion

Nori, Venkata Narasimham 17 June 2008 (has links)
Flame chemiluminescence has received increasing attention for its potential sensor and diagnostic applications in combustors. A number of studies have used flame chemiluminescence to monitor flame status, and combustor performance. While most of these studies have been empirical in nature, chemiluminescence modeling has the potential to provide a better understanding of the chemiluminescence processes and their dependence on various combustion operating conditions. The primary objective of this research was to identify and validate the important chemiluminescence reaction mechanisms for OH*, CH* and CO2*. To this end, measurements were performed at various operating conditions, primarily in laminar, premixed flames, fueled with methane, syngas (H2/CO) and Jet-A. The results are compared to 1-d laminar flame simulations employing the chemiluminescence mechanisms. The secondary objective was to use the experiments and validated chemiluminescence reaction mechanisms to evaluate the usefulness of flame chemiluminescence as a combustion diagnostic, particularly for heat release rate and equivalence ratio. The validation studies were able to identify specific mechanisms for OH*, CH* and CO2* that produced excellent agreement with the experimental data in most cases. The mechanisms were able to predict the variation of the chemiluminescence signals with equivalence ratio but not with pressure and reactant preheat. The possible reasons causing this disagreement could be due to the inaccuracies in the basic chemical mechanism used in the simulations, lack of accurate quenching data (for CH*), thermal excitation (for OH*) and radiative trapping (for OH* and CO2*) and interference from the emissions of other species (such as HCO and H2O), for CO2*. Regarding the utility of chemiluminescence for sensing, a number of observations can be made. In syngas-air flames, CO2* is a reasonable heat release rate marker, at least for very lean conditions. OH* shows some advantage in atmospheric-pressure methane and Jet-A flames in general, while CH* is advantageous at high pressure and very lean conditions at atmospheric pressure. The CO2*/OH* intensity ratio is not useful for sensing equivalence ratio in syngas flames, except maybe at very lean conditions. However, the CH*/OH* signal ratio is a promising approach for sensing equivalence ratio at low or very high pressure conditions in hydrocarbon flames. Thermal excitation and self-absorption processes for OH* chemiluminescence can become important for combustors operating at high pressure, high preheat and near stoichiometric conditions. Background subtracted chemiluminescence signals are recommended for sensing purposes.
59

Matériaux à base de bore pour des applications énergies / boron chemistry for energy application

Ould Amara, Salem 08 November 2017 (has links)
Cette thèse s’articule autour de matériaux à base de bore pour des applications « énergie ». Nous avons développé deux classes de matériaux. (i) La première classe est dédiée au stockage chimique de l’hydrogène. Les matériaux étudiés dans cette partie sont produits par déstabilisation par mécanosynthèse de l’hydrazine borane N2H4BH3 en substituant un hydrogène protique de ce dernier par un cation alcalin. Nous avons particulièrement étudié la modification chimique de l’hydrazine borane par l’amidure de lithium LiNH2, puis par l’hydrure du calcium CaH2. Dans le premier cas, un nouveau composé de formule LiN2H3BH3.0,25NH3 a été obtenu. Dans le second cas, l’hydrazinidoborane de calcium Ca(N2H3BH3)2 a été synthétisé dans des conditions expérimentales spécifiques. (ii) La deuxième classe de matériaux concerne les polyboranes anioniques solubles dans l’eau pour une utilisation comme combustible anodique de pile à combustible liquide. Nous avons synthétisé et pleinement caractérisé le closo-décaborane de sodium Na2B10H10 et le 1-oxa-nido-dodécaborate de sodium NaB11H12O, puis leur électrooxydation a été étudiée et discutée sur différentes électrodes massives (platine, or et argent). Tous nos résultats sont présentés, discutés en détail et mis en perspective dans ce manuscrit de thèse. / The present work is structured around boron-based materials expected to be used in the field of “energy”. We especially worked on two types of materials. (i) With the first type, solid-state hydrogen storage was targeted. Hydrazine borane N2H4BH3 was used as precursor of novel derivatives obtained by mechanosynthesis. We first made it react with lithium amide LiNH2 to obtain LiN2H3BH3.0,25NH3. Then, we considered calcium hydride CaH2; it reacted with N2H4BH3 at 67°C (after ball-milling) to form a new phase, calcium hydrazinidoborane of formula Ca(N2H3BH3)2. (ii) The second type of boron-based materials we investigated is about anionic polyboranes. They are known to be stable in aqueous solution and accordingly could be used as anodic fuel of direct liquid-fed fuel cell. We aimed at synthesizing and fully characterizing two salts: sodium closo-decaborane Na2B10H10 and sodium 1-oxa-nido-dodecaborate NaB11H12O. Their potential for the aforementioned application was tested by cyclic voltammetry by using bulk electrodes of platinum, silver and gold. All of our results are presented, discussed in detail and put into perspective in the present thesis.
60

Hodnocení finanční situace podniku a návrhy na její zlepšení / Evaluation of the Financial Situation in the Firm and Proposals to its Improvement

Vicenová, Lenka January 2010 (has links)
This diploma thesis deals with economic health of the company JAKOS, a.s. in years 2005–2008. There was used selected methods of the financial analysis. Based on recognized facts I propose measures which should result in the improvement of financial situation of the company.

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