In dieser Arbeit werden Modellsysteme der Wechselwirkung von Atomen, Molekülen und deren Ionen mit Festkörperoberflächen studiert. Die Dissertation besteht aus drei Teilen. Im ersten Teil werden Experimente zur Streuung von He0 und He+ mit keV Energien unter streifendem Einfall an Al(111), Al(100) und Al(110) vorgestellt. Anteile überlebender Ionen und Verschiebungen der Winkelverteilungen für einlaufende Atome und Ionen sind in guter Übereinstimmung mit theoretischen Auger-Neutralisationsraten und He-1s-Grundzustandsenergieverschiebungen. Damit liegt ein detailliertes mikroskopisches Verständnis dieses Modellsystems der Atom-Oberflächen-Wechselwirkung vor. Die Studien wurden auf Edelgase und Oberflächen mit komplexerer elektronischer Struktur sowie Ionisationsprozesse erweitert. Im zweiten Teil wird die Formierung von doppelt-angeregten He-Atomen bei der Streuung von He2+ an Ni(110) und Fe(110) mittels Autoionisationsspektren studiert. Diese zeigen eine ausgeprägte Sensitivität auf die Belegung der Oberflächen mit Adsorbaten und deren Umordnung, Desorption bzw. Lösung im Volumen des Festkörpers bei Erhöhung der Temperatur. In diesem Rahmen ergibt sich eine alternative Interpretation aktueller Arbeiten, in denen Autoionisationsspektren zur Ableitung der Spin-Polarisation von Ni- und und Fe-Oberflächen verwendet wurden. Im dritten Teil werden Winkelverteilungen, Fragmentspektren und Ladungsanteile für die streifende Streuung von C60-Molekülionen mit an Al(100), Be(0001) und LiF(100) studiert. Es wird gezeigt, dass die elastischen Eigenschaften des Fullerens durch Metalloberflächen stark modifiziert werden. Anhand von Verschiebungen von Winkelverteilungen für einfach- und zweifach-geladene einlaufende Ionen werden erstmalig Abstände des Elektroneneinfangs für positiv geladene Fullerenionen vor Metalloberflächen gemessen. Für LiF(100) treten ausgeprägte Anregungen der Moleküle durch das periodische elektrische Feld der Oberfläche auf. / This work is devoted to the study of model systems for the interaction of atoms, molecules, and their ions with solid surfaces. The thesis consists of three parts. In the first part, He atoms and ions with keV energies are scattered under grazing angles of incidence from Al(111), Al(100), and Al(110). Fractions of surviving ions and shifts of angular distributions for incident atoms and ions, are in good agreement with theoretically calculated Auger neutralization rates and He 1s ground-state energy shifts. A detailed microscopic understanding for a model system of ion-surface interactions is concluded. The studies are extended to noble gas atoms and surfaces with a more complex electronic structure as well as the Auger ionization process. In the second set of experiments, the formation of doubly excited states of He atoms during collisions of He2+ ions with Ni(110) and Fe(110) is studied via autoionization spectra. The electron spectra show a pronounced dependence on the coverage of the target surface with adsorbates. Thermal desorption and dissolution of surface contaminations into the bulk at elevated temperatures provide an alternative interpretation of recent work where the local electron spin polarization of Ni and Fe surfaces was deduced from autoionization spectra. In the third part, angular distributions, fragmentation, and charge fractions are studied for grazing scattering of C60 fullerene ions from Al(100), Be(0001), and LiF(100). A strong perturbation of the elastic properties of the fullerene by a nearby metal surface is demonstrated. Shifts of angular distributions for incident singly and doubly charged ions for the metal surfaces provide the first information on distances of electron transfer for positively charged fullerenes in front of metal surfaces. For the LiF(100) surface, pronounced internal excitations due to interactions with the periodic electric field at the surface are observed.

In dieser Dissertation wurden die ungewöhnlichen und einzigartigen Eigenschaften von Edelmetall-Clustern untersucht, die durch Quantum-Confinement im Sub-Nanometer-Bereich entstehen. Dabei zeigt sich, dass die chemischen und physikalischen Eigenschaften und damit die Funktionen nicht vom Festkörper abgeleitet werden können und stark von der Anzahl der Atome abhängen. Die erzielten theoretischen Ergebnisse wurden in enger Zusammenarbeit mit experimentell arbeitenden Partnergruppen erzielt. Dabei hat sich gezeigt, dass durch die enge Kooperation zwischen Theorie und Experiment ein tiefes Verständnis von fundamentalen Prozessen und den zugrunde liegenden Mechanismen erlangt werden kann. Im Rahmen dieser Dissertation wurden die Reaktivität von geladenen Goldoxid-Clustern in der Gasphase, die ultraschnelle Dynamik von Edelmetall-Clustern und deren Komplexen sowie die optischen Eigenschaften von kleinen, deponierten Silber-Clustern untersucht und damit Beiträge geliefert, die einzigartigen Eigenschaften von Edelmetall-Clustern im Zusammenhang mit der heterogenen Katalyse und Nano-Optik besser zu verstehen. / In this thesis, the unique novel properties of noble metal clusters which arise in the sub-nanometer size regime due to quantum confinement have been theoretically explored. It has been demonstrated that by adding or removing a single atom the chemical and physical properties and functionality of noble-metal clusters can strongly change. The theoretical results have been derived in close cooperation with experimental findings of partner groups demonstrating that by joint theoretical and experimental efforts thorough understanding of fundamental processes and underlying mechanisms can be achieved. This thesis addresses the reactivity of charged gas-phase gold-oxide clusters in the context of the heterogeneous gold nano-catalysis, the ultrafast dynamical properties of noble-metal clusters and their complexes, and the optical properties of silver clusters at surfaces.

Como sabemos, as reflexões do filósofo político e contratualista Jean-Jacques Rousseau tornaram-se referência para muitos escritores que o sucederam, principalmente no que concerne às suas considerações a propósito da vida em sociedade, ambiente vil que degenera o homem, ser bom e piedoso por natureza. Tratase do célebre conceito rousseauniano do bom selvagem, teoria cuja repercussão pode ser encontrada em obras de muitos autores do período oitocentista, entre as quais podemos destacar a do romancista francês Honoré de Balzac e a do ficcionista português Camilo Castelo Branco. Isto porque, a partir de um estudo comparativo realizado entre volumes balzaquianos e camilianos, levantou-se a hipótese de que estes escritores, ao tecerem suas críticas sociais, dialogam com a mencionada teoria de Rousseau, muito embora cada um o faça a seu modo e finde por concatenar mundividências literárias distintas, únicas e inovadoras, que particularizam, de forma marcante, ambos os cânones ficcionais. Assim posto, e levando em consideração a ausência de estudos críticos a esse respeito, nosso intento é o de analisar uma questão inédita no que concerne à comparação entre a ficção balzaquiana e a camiliana: a diferente concepção que os respectivos narradores apresentam acerca dos efeitos sociais no homem, a partir de um diálogo estabelecido por ambos com o conceito rousseauniano do bom selvagem. Vale ressaltar que o estudo comparativo aqui proposto seguirá alguns pressupostos básicos da Literatura Comparada, sendo o principal deles a busca pelas particularidades de cada literatura (Cf. ABDALA Jr., 2003). / As we know, the reflections of the political and contractualist philosopher Jean- Jacques Rousseau became reference for many writers who succeeded him, mainly as concerns the considerations regarding the life in society, a vile ambience that degenerates man, a good and pious living being by nature. This is the renowned Rousseaunian concept of the noble savage, theory that can be found reverberated in many works of 19th century authors, among which we can highlight the one of the French novelist Honoré de Balzac and the one of the Portuguese fictionist Camilo Castelo Branco. That is because, from a comparative study realized between Balzacian and Camilian works, we hypothesized that these writers dialogue, as they construct their social criticisms, with the mentioned Rousseaus theory, although each one does it in his own way and ends by concatenating distinct literary worldviews, unique and innovative, that particularize, markedly, both of the fictional canons. Therefore, and taking into consideration the absence of critical studies regarding this, our intent is to analyze an unprecedented issue concerning the comparison between Balzacian and Camilian fiction: the different conception the narrators present about the social effects in man, through a dialogue established by both of them with the Rousseaunian concept of the noble savage. It is worth to stress that the comparative study proposed here will follow some basic assumptions of Comparative Literature, the main one being the research for the particularities of each literature. (Cf. ABDALA Jr., 2003).

Les propriétés structurales, optiques et photocatalytiques de revêtements sol-gel TiO2 ont été étudiées. Une importance particulière a été donnée à l'influence de nanoparticules métalliques de platine sur l'activité photocatalytique. Pour cela, plusieurs protocoles de platinisation par voie photochimique ont été prospectés afin de disperser des particules de platine à la surface des revêtements TiO2. Nous montrons comment un contrôle adapté de la taille, du taux et de la dispersion des particules de platine, lesquels relèvent de paramètres d'élaboration optimisés, conduit à une augmentation d'activité photocatalytique par un facteur 3 à 4 par rapport à des revêtements non platinisés. Ces études ont aussi mis en évidence le magnétisme inusuel des nanoparticules de platine formées par voie photochimique, ainsi que le potentiel de ces particules pour des applications (photo)-électrochimiques. Ces voies d'élaboration photochimiques ont également été extrapolées à la synthèse de nanoparticules d'or et d'argent dont le potentiel pour des applications en optique et plasmonique est discuté.

Polymer electrolyte fuel cells (PEFC) convert chemicalenergy into electrical energy with higher efficiency thaninternal combustion engines. They are particularly suited fortransportation applications or portable devices owing to theirhigh power density and low operating temperature. The latter ishowever detrimental to the kinetics of electrochemicalreactions and in particular to the reduction of oxygen at thecathode. The latter reaction requires enhancing by the verybest catalyst, today platinum. Even so, the cathode isresponsible for the main loss of voltage in the cell. Moreover,the scarce and expensive nature of platinum craves theoptimisation of its use. The purpose of this thesis was to better understand thefunctioning of the porous cathode in the PEFC. This wasachieved by developing physical models to predict the responseof the cathode to steady-state polarisation, currentinterruption (CI) and electrochemical impedance spectroscopy(EIS), and by comparing these results to experimental ones. Themodels account for the kinetics of the oxygen reduction as wellas for the transport of the reactants throughout the cathode,i.e. diffusion of gases and proton migration. The agglomeratestructure was assumed for the description of the internalstructure of the cathode. The electrochemical experiments wereperformed on electrodes having a surface of 0.5 cm2 using alaboratory fuel cell. The response of the cathode to various electrodecompositions, thickness, oxygen pressure and relative humiditywas experimentally investigated with steady-state polarisation,EIS and CI techniques. It is shown that a content in thecathode of 35-43 wt % of Nafion, the polymer electrolyte, gavethe best performance. Such cathodes display a doubling of theapparent Tafel slope at high current density. In this region,the current is proportional to the cathode thickness and to theoxygen pressure, which, according to the agglomerate model,corresponds to limitation by oxygen diffusion in theagglomerates. The same analysis was made using EIS. Moreover,experimental results showed that the Tafel slope increases fordecreasing relative humidity. For Nafion contents lower than 35wt %, the cathode becomes limited by proton migration too. ForNafion contents larger than 40 wt %, the cathode performance athigh current density decreases again owing to an additionalmass transport. The latter is believed to be oxygen diffusionthroughout the cathode. The activity for oxygen reduction ofcatalysts based on iron acetate adsorbed on a carbon powder andpyrolysed at 900°C in ammonia atmosphere was alsoinvestigated. It was shown that the choice of carbon has atremendous effect. The best catalysts were, on a weight basis,as active as platinum. <b>Keywords:</b>polymer electrolyte fuel cell, cathode, masstransport, porous electrode, modelling, agglomerate model,electrochemical impedance spectroscopy, current interrupt,transient techniques, non-noble catalysts

This study aims the real-time monitoring of gases (CO2, N2, O2, H2, H2S, CH4, He, Ar) discharging from natural pools in the Tekke Hamam geothermal field (Denizli) in addition to the geochemical characterization of the field along with the Kizildere geothermal field, both located at the eastern segment of the B&uuml / y&uuml / k Menderes Graben. The continuous gas monitoring experiment (November 2007-October 2008) conducted in the Tekke Hamam geothermal field has revealed temporal variations in the gas compositions, gas flow rate and pool temperature. Different variation components, such as daily variation profiles and peak/Multi-day signals, are detected in the monitored data, which are mainly correlated with shallow and deep processes involving mainly meteorological factors and seismicity induced variations, respectively. Particularly, the coupled variations in the gas compositions and flow rate seem to correlate with seismicity induced permeability modifications within the subsurface during the absence of significant meteorological factors, such as high rainfall and varying atmospheric pressure. The noble gas characterization of the fields have revealed both high 3He/4He and 4He/20Ne isotopic ratios, suggesting a mantle contribution of about 18% for Kizildere and 34% for Tekke Hamam, whereas the other noble gases (Ar, Ne, Kr, Xe) are of atmospheric nature. The different mantle contributions observed in both fields can suggest a different mantle-He flux variably contaminated by crustal helium. The chemical (cation-trace element-anion) and stable isotopic (&amp / #948 / 18O-&amp / #948 / D) contents of the thermal waters reveal high temperature water-rock interaction accompanied by the effects of deep origined gases (mainly CO2 and H2S) discharging from the fields.

<p>Polymer electrolyte fuel cells (PEFC) convert chemicalenergy into electrical energy with higher efficiency thaninternal combustion engines. They are particularly suited fortransportation applications or portable devices owing to theirhigh power density and low operating temperature. The latter ishowever detrimental to the kinetics of electrochemicalreactions and in particular to the reduction of oxygen at thecathode. The latter reaction requires enhancing by the verybest catalyst, today platinum. Even so, the cathode isresponsible for the main loss of voltage in the cell. Moreover,the scarce and expensive nature of platinum craves theoptimisation of its use.</p><p>The purpose of this thesis was to better understand thefunctioning of the porous cathode in the PEFC. This wasachieved by developing physical models to predict the responseof the cathode to steady-state polarisation, currentinterruption (CI) and electrochemical impedance spectroscopy(EIS), and by comparing these results to experimental ones. Themodels account for the kinetics of the oxygen reduction as wellas for the transport of the reactants throughout the cathode,i.e. diffusion of gases and proton migration. The agglomeratestructure was assumed for the description of the internalstructure of the cathode. The electrochemical experiments wereperformed on electrodes having a surface of 0.5 cm2 using alaboratory fuel cell.</p><p>The response of the cathode to various electrodecompositions, thickness, oxygen pressure and relative humiditywas experimentally investigated with steady-state polarisation,EIS and CI techniques. It is shown that a content in thecathode of 35-43 wt % of Nafion, the polymer electrolyte, gavethe best performance. Such cathodes display a doubling of theapparent Tafel slope at high current density. In this region,the current is proportional to the cathode thickness and to theoxygen pressure, which, according to the agglomerate model,corresponds to limitation by oxygen diffusion in theagglomerates. The same analysis was made using EIS. Moreover,experimental results showed that the Tafel slope increases fordecreasing relative humidity. For Nafion contents lower than 35wt %, the cathode becomes limited by proton migration too. ForNafion contents larger than 40 wt %, the cathode performance athigh current density decreases again owing to an additionalmass transport. The latter is believed to be oxygen diffusionthroughout the cathode. The activity for oxygen reduction ofcatalysts based on iron acetate adsorbed on a carbon powder andpyrolysed at 900°C in ammonia atmosphere was alsoinvestigated. It was shown that the choice of carbon has atremendous effect. The best catalysts were, on a weight basis,as active as platinum.</p><p><b>Keywords:</b>polymer electrolyte fuel cell, cathode, masstransport, porous electrode, modelling, agglomerate model,electrochemical impedance spectroscopy, current interrupt,transient techniques, non-noble catalysts</p>

Underground nuclear explosions (UNEs) produce anthropogenic isotopes that provide the only definitive means by which to determine whether a nuclear explosion has taken place. Verification of a suspected test under the Comprehensive Nuclear-Test-Ban Treaty (CTBT) includes both on-site and atmospheric sampling of specific noble gas radioisotopes for analysis of origin. It is well-established that the processes of subsurface transport can affect the rate at which such gases will reach the surface. However, the relative abundance of anthropogenic isotopes reaching the surface following transport is currently assumed to rely solely on their direct fission yield, decay rate, and their production from precursor decay, making no account for the influence of transport processes on isotopic ratios. The Underground Transport of Environmental Xenon (UTEX) model has been developed to examine the possible effects of subsurface transport on radioxenon isotopic ratios as well as to consider a number of on-site inspection-related applications. In this work, background on the UTEX model's development, evolution and vetting is presented. This is followed by the characterization and analysis of a number of applications of the model for consideration of CTBT-relevant scenarios. Specifically, the UTEX model's capability to analyze CTBT on-site inspection concept of operations is demonstrated. This is accomplished through an examination of generalized UNE source terms, geological stratigraphy, UNE impact on local geology, natural soil-gas radionuclide backgrounds, atmospheric infiltration, and sampling methodology. It is shown that the processes driving noble gas transport through geological media can significantly skew the ratios of key radioxenon isotopes that are used to help verify whether or not a well-contained underground test has taken place. This result emphasizes the need for a broader understanding of radionuclide signatures used for CTBT verification purposes and the mechanisms that can alter them. / text

This thesis focuses on the anachronistic poacher-hero figure in late nineteenth-century German literature. Historian Hobsbawm has suggested that the symbolic endurance of "noble robber" figures (of which we can view poacher-heroes as a subset) takes place in an ideal imaginary "stripped" of the "local and social framework" (2000, 143). My thesis shows, in multiple examples across multiple genres, that in fact the poacher-hero is uniquely available for re-contextualization and renewal of social relevance, even under changed social and economic circumstances. The poacher-hero is not only a device for making statements about the past, but also for expressing claims on the future. It is perhaps this dynamism that makes the poacher-hero excellent carrier for different kinds of social critique as well. In my first chapter, I give a brief historical overview of the period and the motif. In the second chapter, I show how the poacher and his rural context are brought into contact with urban, imperial themes. In the chapter I read two novels, Der verlorene Sohn (The prodigal son, 1884-1886) and Quitt (Even, 1890), and the play Waldleute (Forest people, 1896) thematically to show how upward social mobility is associated with and adapted to the poacher figure. In the third chapter of the thesis, I examine narrative strategies and their employment in the construction of a socially critical viewpoint in Der verlorene Sohn and Quitt. I show how both high and low literary works, intended and written for different audiences, achieve similar results in their positioning of the poacher-protagonist through different narrative structures. This convergence shows the malleability of the societal frame for the poacher-hero. Finally, in the fourth chapter, I show regional adaptations of the motif, by examining different versions of a folk ballad "Das Jennerweinlied" ("The Jennerwein song"). This thesis furthermore shows how study of a motif can be used to bring together a diverse group of roughly contemporary texts. Viewing these texts in relationship with one another brings into question the scholarly focus on certain texts at the expense of others. / text

Tyrimo objektas: Rizikos grupės vaikų požiūris į olimpinį judėjimą ir kilnų elgesį sporte olimpinio ugdymo kontekste; Tyrimo tikslas – išsiaiškinti rizikos grupės vaikų požiūrį į olimpinį judėjimą ir kilnų elgesį sporte olimpinio ugdymo kontekste. Siekinat atsakyti į tyrimo tikslą, buvo keliami šie uždaviniai: išnagrinėti olimpizmo idėjų sklaidą mokykloje olimpinio ugdymo kontekste; įvertinti rizikos grupės vaikų žinias apie olimpines žaidynes olimpinio ugdymo kontekste; nustatyti mokykloje vykdomos olimpinio ugdymo programos poveikį rizikos grupės vaikų požiūriui į olimpinį judėjimą ir kilnų elgesį sporte olimpinio ugdymo kontekste; Tyrimu tikrinama hipotezė, kad mokyklos, kurios vaikai dalyvauja olimpinio ugdymo projekte požiūris į olimpinį judėjimą ir kilnų elgesį sporte pozityvesnis nei mokyklos, kurios vaikai minėtame projekte nedalyvauja. Tyrimo metu, taikant netikimybinę tikslinę atranką bei apklausos raštu metodą buvo apklausta 120 rizikos grupei priklausančių vaikų (60 vaikų iš mokyklos, kuri dalyvauja olimpinio ugdymo programoje bei 60 vaikų iš mokyklos, nedalyvaujančios minėtoje programoje). Taikyta dalis Olimpinio klausimyno (Olympic Questionnaire, Telama et al., 2002). Apklausa parodė, kad mokyklos, kurios vaikai dalyvauja olimpinio ugdymo projekte požiūris į olimpinį judėjimą ir kilnų elgesį sporte pozityvesnis nei mokyklos, kurios vaikai minėtame projekte nedalyvauja. Nustatyta, kad žinių apie olimpines žaidynes rizikos grupės vaikai pirmiausia gauna... [toliau žr. visą tekstą] / Research object: Children‘s at risk attitude about Olympic Movement and noble behavior in sports in the context of Olympic education; Goal of research – to find out children‘s at risk attitude about Olympic Movement and noble behavior in sports in the context of Olympic education. On purpose to reach the goal of research, the following objectives have been raised: to analyze the dispersion of Olympism ideas in school in the context of Olympic education; to evaluate children‘s at risk knowledge about Olympics in the context of Olympic education; to determine the influence of Olympic education program in school for children‘s at risk attitude about Olympic Movement and noble behavior in sports in the context of Olympic education. The hypothesis, evaluating by research is, that the attitude about Olympic Movement and noble behavior in sports in school, in which children participate in the Olympic education project is more positive than in school, in which children don‘t participate in the earlier mentioned project. During the research, using non-stochastic objective selection and the method of written survey, 120 children from at-risk group (60 children from school, which participates in Olympic education program and 60 children from school, which is not participating in mentioned program) were interviewed. There was a part of Olympic Questionnaire used (Olympic Questionnaire, Telama et al., 2002). A survey showed, that the attitude about Olympic Movement and noble behavior in... [to full text]