Thesis (M.S.)--Indiana University, 2009. / Department of Geography, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Jeffrey S. Wilson, Lenore P. Tedesco, Daniel P. Johnson. Includes vitae. Includes bibliographical references (leaves 71-77).

A large concern of the fossil fuel and renewable energy industries is the sulfur poisoning of catalysts. In the case of noble metals, such as platinum, it is seen that there is a size trend associated with the level of activity in the presence of sulfur. Smaller nanoparticles could be more tolerant due to sulfur surface vacancies. On the other hand, larger particles could have less deactivation because the sulfur is more attracted to the smaller particles and the sulfur molecules bind stronger to these smaller particles. The size effect of sulfur deactivation was investigated by testing four sizes of nanoparticles, ranging from 2 - 7 nm with and without sulfur by running an ethylene hydrogenation reaction. The synthesized particles were characterized by mass spectrometry, X - ray diffraction, and transmission electron microscopy. The 7 nm catalyst resulted in being the most sulfur tolerant due to the sulfur particles binding strongly to the smaller particles.

New challenges in nanotechnology arise in the assembly of nanoobjects into three-dimensional superstructures, which may carry synergetic properties and open up new application fields. Within this new class of materials nanostructured, porous functional metals are of great interest since they combine high surface area, gas permeability, electrical conductivity, plasmonic behavior and size-enhanced catalytic reactivity. Even though a large variety of preparation pathways for the fabrication of porous noble metals has already been established, several limitations are still to be addressed by research developments. The new and versatile approach that is presented in this work makes use of a templatefree self-assembly process for the fabrication of highly porous, metallic nanostructures. Thereby, nanochains are formed by the controlled coalescence of noble metal NPs in aqueous media and their interconnection and interpenetration leads to the formation of a self-supported network with macroscopic dimensions. Subsequently, the supercritical drying technique is used to remove the solvent from the pores of the network without causing a collapse of the fragile structure. The resulting highly porous, low-weighted, three-dimensional nanostructured solids are named aerogels. The exceptional properties of these materials originate from the conjunction of the unique properties of nanomaterials magnified by macroscale assembly. Moreover, the combination of different metals may lead to synergetic effects regarding for example their catalytic activity. Therefore, the synthesis of multimetallic gels and the characterization of their structural peculiarities are in the focus of the investigations. In the case of the developed preparation pathways the gelation process starts from preformed, stable colloidal solutions of citrate capped, spherical noble metal (Au, Ag, Pt, Pd) NPs. In order to face various requirements several methods for the initiation of the controlled destabilization and coalescence of the nanosized building blocks were developed and synthesis conditions were optimized, respectively. Multimetallic structures with tunable composition are obtained by mixing different kinds of monometallic NP solutions and performing a joint gel formation. The characterization of the resulting materials by means of electron microscopy reveals the formation of a highly porous network of branched nanochains that provide a polycrystalline nature and diameters in the size range of the initial NPs. Furthermore, synthesis conditions for the spontaneous gel formation of glucose stabilized Au and Pd NPs were investigated. In order to gain a detailed knowledge of the structural properties of bimetallic aerogel structures a versatile set of characterization techniques was applied. A broad pore size distribution dominated by meso- and macropores and remarkably high inner surface areas were concluded from the N2 physisorption isotherms and density measurements. As investigated, a specific thermal treatment could be used to tune the ligament size of Au-Ag aerogels, whereas Au-Pd and Pt-Pd structures provide thermal stability under mild conditions. Further investigations aimed to the enlightenment of the elemental distribution and phase composition within the nanochains of multimetallic gel structures. The different approaches provide complementary and consistent results. Phase analyses based on XRD measurements revealed separated phases of each metal in the case of Ag-Pd and Au-Pd aerogels. They further proved the possibility of temperature induced phase modifications that lead to complete alloying of Au and Pd. In addition, separated domains of Pt and Pd were established from the EXAFS analysis of the corresponding aerogel. STEM EDX high resolution elemental mappings confirmed the separated domains of different metals in the case of Au-Pd and Pt-Pd aerogels. Moreover, a complete interdiffusion and alloy formation of Au and Ag within the corresponding aerogel structure is suggested from STEM EDX results. Finally, the presented investigations further promote the field of metallic aerogels by addressing the challenging issue of processability and device fabrication. Hybrid materials with organic polymers as well as various kinds of coatings on glass substrates and glassy carbon electrodes were prepared whereas the network structure was preserved throughout all processing steps. Moreover, it was illustrated that the NP-based aerogels carry metallic properties as expressed by their low Seebeck coefficients and high electrical conductivities.

Historical notions of Noble Savagery have been contemporarily translated and massified in popular culture so that traits that “Indigenous People” are believed to possess, are conflated with those of the Noble Savage of lore and taken for granted as truth. The Noble Savage is the embodiment of the tourist’s notion of the authentic; the more traits Indigenous people are assumed to share with the western notion of the Noble Savage the more authentic they are deemed, and the more attractive they are to the visiting tourist. In Saraguro tourism and incanismo mutually validate and reinforce each other. Tourists valorize their own preconceived notions of indigenous culture, and in turn validate incanismo through participation in Incaic cultural performances. Neo-Incans are objectifying and consuming their own dreams though the tourist gaze, and the resultant cultural commodification and the (re)appropriation of a nobler past has led to cultural revalorization of an indigenous elite. / viii, 213 leaves; 29 cm

The purpose of this work is to measure the influence of the Dialogues of Lahontan (1702--3) on contemporary thought relative to the myth of the Noble Savage. The text is divided into two parts: (1) Lahontan and the idea of the "noble savage" at the beginning of the 18th century in which we deal with the life of Lahontan, the historical and cultural background in New-France and in Europe at the turn of the 18th century, the Indian tribes of Northeastern America, and finally the Dialogues of Mr le Baron de Lahontan et d'un Sauvage, which consist in a comparison between two ways of life: the "civilized" i.e., European and the "savage" i.e., Amerindian. (2) The idea of the "noble savage" in the XXth century: a study of four representative authors. This part is divided in four chapters relative to the authors chosen. In chronological order: Charles Eastman who published his works at the beginning of the century, Sun Bear in the 70s, Georges Sioui and Jean Pictet after 1970. Each author's ideas are compared with those of Lahontan and, where it applies, with those of the other authors. / The conclusion underlines the fact that the ideas expressed in the four contemporary texts, having of course characteristics marking them as belonging to their specific historical milieu, borrow much from Lahontan and finally go back to a trend of thought that originated in Antiquity.

In Canada’s western Arctic, perennial discharge from permafrost watersheds is the surface manifestation of active groundwater flow systems, yet understanding the mechanisms of groundwater recharge and flow in periglacial environments remains enigmatic. This thesis addresses questions on how and where groundwater recharge occurs. Watersheds were selected in Yukon (Fishing Branch River at Bear Cave Mountain) and the Northwest Territories at latitudes spanning from continuous to discontinuous permafrost (five tributary rivers to the Mackenzie River from Wrigley to Aklavik). All are characterized by perennial flow with open water in the winter, and discharge from sedimentary formations of karstic carbonates and evaporate rocks. Determinations of groundwater contributions to discharge, mixing, recharge conditions and circulation times were made on the basis of a suite of analytical approaches involving measurements of major dissolved ions, δ18O, δD, δ13CDIC, 3H, noble gases and flow gauging was conducted at some sites. The application of these tracers show that hydrogeological conditions and flow paths in permafrost terrains are surprisingly similar to those of temperate regions. Groundwater recharge was determined to be a mix of annual precipitation with contributions from snowmelt and precipitation. All systems investigated show that groundwaters have recharged through organic soils with elevated PCO2, which suggests that recharge occurs largely during summer when biological activity is high. Noble gas concentrations show that the recharge temperature was between 0 and 6 °C, which, when considered in the context of discharge temperatures, suggests that there is no significant imbalance of energy flux into the subsurface. Groundwater ages were found using the 3H-3He method and were dependent on flow path. By characterizing groundwater and surface water chemistry, the proportion of groundwater was found in numerous water courses. The possible impact of ground ice formation and melting on noble gas concentrations in groundwater was considered. To assess this link, a new method to measure the noble gas composition of ground ice bodies was developed. The method can be used to determine the origin of ice, based on changes in noble gas ratios between ice originating from compaction of snow (e.g. glacier ice) vs. ice originating from freezing of water. No significant fractionation of noble gases during groundwater freezing and ground ice formation was identified. Applied to determination of the origin of ground ice bodies, the method was shown to be both diagnostic of ice origin and un-encumbered by reactivity in the subsurface, which compromises the use of the dominant atmospheric gases (O2 and N2).   Résumé Dans l’Ouest de l'Arctique canadien, la décharge pérenne dans certaines rivières en région de pergélisol est la manifestation en surface d’une circulation d’eau souterraine; cependant la compréhension des mécanismes d’écoulement et de recharge des eaux souterraines en région de pergélisol demeure énigmatique. Cette thèse s’intéresse à la question de savoir comment et où la recharge des eaux souterraines se produit. Des bassins versants ont été choisis au Yukon (Rivière Fishing Branch à Bear Cave Mountain) et dans les Territoire du Nord-Ouest à des latitudes s’étendant du pergélisol discontinu au pergélisol continu (cinq tributaires du Mackenzie entre Wrigley et Aklavik). Toutes ces rivières ont un écoulement d’eau pérenne avec des zones non gelées et une décharge dans des formations sédimentaires de roches carbonatées et d‘évaporites. L’identification des contributions des eaux à la décharge, les mélanges, les conditions de recharge, et les temps de circulation ont été faits à partir d’analyses qui ont inclus les concentrations en éléments majeurs, leur valeur isotopique (δ18O, δD, δ13C, 3H), ainsi que leur teneur en gaz rares. A certain des sites analysés des mesures d’écoulement ont été prises. L’application de ces traceurs montre que les conditions hydrauliques et le chemin des écoulements en région de pergélisol sont similaires à ceux des régions tempérées. La recharge en eau souterraine a été identifiée comme étant un mélange de précipitations annuelles, avec des contributions de neige et de pluies. Tous les systèmes étudiés montrent que les eaux souterraines se sont rechargées en traversant des sols organiques avec une PCO2 élevée, ce qui suggère que la recharge se produire largement durant l’été quand l’activité biologique est élevée. Cependant, les concentrations en gaz nobles montre que la température de recharge des eaux souterraines était entre 0 et 6 °C ce qui indique qu’il n’y a pas de déséquilibre de flux d’énergie à l’intérieur de la zone proche de la surface. L’âge des eaux a été déterminé par la méthode 3H-3He et cet âge est dépendant du chemin d'écoulement. En caractérisant les paramètres chimiques des eaux de surface et des eaux souterraines, il a été possible de trouver la contribution des eaux souterraines aux eaux surface. Le possible impact de la formation et de la fonte de la glace souterraine sur les concentrations des gaz nobles a été considéré. Pour déterminer s’il y a un lien entre ceux-ci, une nouvelle méthode pour mesurer la concentration en gaz nobles dans les glaces souterraines a été développée. La méthode peut être utilisée pour déterminer l’origine de la glace; elle est basée sur les changements dans les rapports des gaz nobles entre la glace issue de la compaction de la neige (c’est-à-dire la glace de glacier) par opposition à la glace issue du gel de l’eau. Aucun fractionnement significatif des gaz nobles durant l’engel des eaux souterraines et la formation de glaces souterraines n’a été identifié. Appliquée à l’identification de l’origine des masses de glace enfouies, on a montré que la méthode pouvait permettre d’identifier l’origine des glaces souterraines sans qu’elle soit affectée par des réactions biologiques de sub-surface, lesquelles rendent inutilisables les gaz atmosphériques (O2, and N2).

abstract: Low temperature fuel cells are very attractive energy conversion technology for automotive applications due to their qualities of being clean, quiet, efficient and good peak power densities. However, due to high cost and limited durability and reliability, commercialization of this technology has not been possible as yet. The high fuel cell cost is mostly due to the expensive noble catalyst Pt. Alkaline fuel cell (AFC) systems, have potential to make use of non-noble catalysts and thus, provides with a solution of overall lower cost. Therefore, this issue has been addressed in this thesis work. Hydrogen-oxygen fuel cells using an alkaline anion exchange membrane were prepared and evaluated. Various non-platinum catalyst materials were investigated by fabricating membrane-electrode assemblies (MEAs) using Tokuyama membrane (# A201) and compared with commercial noble metal catalysts. Co and Fe phthalocyanine catalyst materials were synthesized using multi-walled carbon nanotubes (MWCNTs) as support materials. X-ray photoelectron spectroscopic study was conducted in order to examine the surface composition. The electroreduction of oxygen has been investigated on Fe phthalocyanine/MWCNT, Co phthalocyanine/MWCNT and commercial Pt/C catalysts. The oxygen reduction reaction kinetics on these catalyst materials were evaluated using rotating disk electrodes in 0.1 M KOH solution and the current density values were consistently higher for Co phthalocyanine based electrodes compared to Fe phthalocyanine. The fuel cell performance of the MEAs with Co and Fe phthalocyanines and Tanaka Kikinzoku Kogyo Pt/C cathode catalysts were 100, 60 and 120 mW cm-2 using H22 and O2 gases. This thesis also includes work on synthesizing nitrogen doped MWCNTs using post-doping and In-Situ methods. Post-doped N-MWNCTs were prepared through heat treatment with NH4OH as nitrogen source. Characterization was done through fuel cell testing, which gave peak power density ~40mW.cm-2. For In-Situ N-MWCT, pyridine was used as nitrogen source. The sample characterization was done using Raman spectroscopy and RBS, which showed the presence ~3 at.% of nitrogen on the carbon surface. / Dissertation/Thesis / M.S.Tech Technology 2012

Signal crayfish (Pacifastacus leniusculus) is important invasive species in European freshwaters. Its influence on other freshwater organisms is well known from the literature, as well as direct and indirect impact on fish assemblages. This work was focused on the experimental evaluation of non-indigenous signal crayfish as a predator of salmonids compared to indigenous noble crayfish (Astacus astacus). Moreover, the possible importance of young-of-the-year signal crayfish as a prey for salmonids was assessed. There were carried out experiments using eggs and hatchings of grayling (Thymallus thymallus) as a prey for adult and subadult specimens of both, signal and noble crayfish. Next experiment used young-of-the-year signal crayfish as a prey for young-of-the-year of brown trout (Salmo trutta). Results showed that the danger of signal crayfish for grayling eggs is slightly higher. However, detected differences were surprisingly lower and in the majority of parameters even insignificant. In the case of grayling hatchings, was not detected any significant difference at all. The abilities of both tested species to prey on eggs and hatchings are therefore very similar, comparable. Even so, the effect of signal crayfish can be importantly higher in natural conditions because of its more dense populations, higher growth rate and fast maturation. In accordance to our findings, it is evident that brown trout has no so high effect of crayfish juveniles compared with crayfish effect on salmonids early developmental stages. Crayfish are therefore more likely able to limit salmonids than conversely.

This essay explores the choices and fates of three women in Thomas Hardy’s A Group of Noble Dames. The lives of Betty Dornell, Emmeline Oldbourne and Barbara Grebe are all influenced by chance, choice and the interference of their parents and lovers. Despite the similar circumstances of their lives as young, upper-class women, it is shown that their fates vary widely as a result of both choice and chance. Ultimately, however, this essay claims that Hardy allows chance to have the final say in each dame’s destiny.

A síntese de Fischer-Tropsch é um processo de conversão do gás de síntese (CO + H2) em hidrocarbonetos de cadeias longas. Os catalisadores clássicos para a hidrogenação do CO são, principalmente, o Fe e o Co suportados em diferentes óxidos. O desempenho catalítico do catalisador é influenciado pelo tamanho, dispersão e grau de redução das partículas metálicas. Estudos recentes mostram uma promissora aplicação de materiais à base de nanofibras de carbono na catálise heterogênea. Estes materiais apresentam algumas vantagens em relação aos suportes catalíticos tradicionais, tais como: uma baixa interação metal-suporte, elevada área superficial, ausência de poros fechados, alta condutividade térmica, elevada inércia química e hidrofobicidade. Neste trabalho foram fabricados suportes catalíticos macroscópicos à base de nanofibras de carbono, empregando o método de vapor deposição, a partir da decomposição do etano. Os catalisadores foram preparados pela impregnação incipiente do Co e de promotores na superfície do suporte. Foram empregados os metais nobres, Ir, Pt e Ru, como promotores catalíticos, com o objetivo de incrementar a redutibilidade e a atividade do catalisador. Todos os catalisadores foram caracterizados por Quimissorção de CO, Fisissorção de N2, Redução a Temperatura Programada (TPR), Espectroscopia Fotoeletrônica de Raios X (XPS) e Microscopia Eletrônica de Transmissão (MET). Os catalisadores foram, então, testados na síntese de Fischer-Tropsch, utilizando um reator de leito fixo e fluxo contínuo, com análise simultânea dos produtos gasosos e controle sistemático da temperatura, pressão e vazão dos reagentes. Finalmente, foram analisados os produtos líquidos obtidos na reação com objetivo de conhecer a influência dos promotores na seletividade dos hidrocarbonetos formados. / Fischer-Tropsch synthesis is a process of converting the syngas (CO + H2) to long-chain hydrocarbons. The traditional catalysts for the CO hydrogenation are Fe and Co supported on different oxides. Catalytic performance of the catalyst is influenced by size, dispersion and degree of reduction of metal particles. Recent studies show a promising application of materials based on carbon nanofibers in heterogeneous catalysis. These materials have some advantages compared to traditional catalyst supports, such as a low metal support interaction, high surface area, no closed pores, high thermal conductivity, high chemical resistance, and hydrophobicity. In this work, based on macroscopic carbon nanofiber catalyst supports have been manufactured by employing the method of chemical vapor deposition from ethane decomposition. Catalysts were prepared by incipient wetness impregnation of Co and promoters on the support surface. Noble metals, Ir, Pt and Ru were used as catalytic promoters, with the aim of increasing the reductibility and catalyst activity. All catalysts were characterized by CO Chemisorption, N2 Physisorption, Temperature Programmed Reduction (TPR), X-ray Photoelectron Spectroscopy (XPS), and Transmission Electron Microscopy (TEM). The catalysts were then tested in the Fischer-Tropsch synthesis using a fixed bed reactor, continuous flow, with simultaneous analysis of gaseous products and systematic temperature control, pressure, and flow rate of the reactants. Finally, the liquid products obtained in the reaction were analyzed in order to determine the influence of promoters on the selectivity of hydrocarbons formed.