Zugl.: München, Univ., Habil.-Schr. 2004

Green ammonia production has been an important topic that is being researched during the last decades due to the increasing demand and to cut down CO2 emissions. One of the promising pathways to achieve green chemical energy synthesis is the Photoelectrochemical (PEC) approach. To realize low-cost and scalable green ammonia production, the direct integration of solar photovoltaic modules and catalysts as a Photovoltaic-Electrochemical (PV-EC) system is highly suitable. In this study, Molybdenum Carbide(Mo2C) decorated with different metal nanoparticles (Pt, Pd, Ru) is being investigated as a potential nitrate reduction (NO3RR) to ammonia. Here various metal-decorated M o2C was successfully synthesized by the chemical reduction method. The metal-decorated M o2C is characterized by Transmission Electron Microscopy(TEM), Raman Spectroscopy, and X-ray diffraction(XRD) analysis and confirmed the formation. Initially, electrocatalytic NO3RR was carried out, and Pt decorated Mo2C was found to demonstrate high Faradic efficiency and NH3 of 30% and 4400 μg/h/cm2. Next, PV-EC was carried out, and a stable solar-powered NO3RR was carried out with Pt-M o2C and Si PV module. The proposed system delivers a yield of 600 ug/h/cm2 and a Faradic Efficiency of 7% .

Doctor of Philosophy / Department of Chemical Engineering / Peter H. Pfromm / Mary E. Rezac / Multiphase reactions are often constrained by mass transfer limitations which in many cases lead to low reaction rates and undesirable product distribution. Here we fabricate integral-asymmetric polymeric membranes decorated with metal catalysts, to supply hydrogen directly at or near the surface of the catalyst, thus minimizing mass-transfer limitations. The metal decorated polymeric membranes were used for partial hydrogenation of soybean oil with the goal to minimize trans fatty acid (TFA) formation. It was discovered that polymeric membranes with “defective” metal coatings are well suited to achieve low-TFA hydrogenation of soybean oil at quite moderate process conditions. The metal decorated polymeric membranes studied produced significantly lower trans fatty acid as compared to traditional reactors (3.5 wt% at an Iodine Value of 95 as compared to 8 wt% in slurry reactor), at pressures and temperatures which are compatible with the existing systems. The process concept is simpler than some of the alternatives being studied and no catalyst recovery from the oil is needed since the catalyst is immobilized on the membrane. Metal decorated polymeric membranes having a variety of hydrogen fluxes, skin defects, and catalyst loadings were evaluated. All the metal decorated polymeric membranes evaluated produced low TFA. Membranes with high hydrogen fluxes resulted in higher hydrogenation rates but had little influence on TFA formation. Membranes with higher catalyst loadings resulted in lower TFA but increased saturate formation. Metal decorated polymeric membranes behaved differently to changes in temperature and pressures when compared to traditional slurry reactors. They showed a minor increase in TFA with temperature (50-90 °C) as compared to traditional slurry reactors. The hydrogenation rate and cis-trans isomerization also showed a modest dependence on pressure. Due to the defective nature of the metal layer on the polymeric membrane skin and the low temperatures (50-90 °C) at which the reactor is operating, the hydrogen permeability of metals has a minor influence on hydrogenation reaction. A range of metal catalysts can be used for the given system. Repeat runs using the same membrane showed a decrease in hydrogenation activity, without any change in isomerization or hydrogenation selectivity. Initial results indicate the decreased activity may not be from leaching of catalyst from membrane surface nor from sulfur poisoning.

<p>This dissertation is the first architectural history devoted to Beverley Minster, a large and ambitious Gothic church located in the East Riding of Yorkshire. Beverley is one of the most important medieval buildings in England, but it has been almost entirely ignored in the literature. The church is composed of three parts: choir and transepts (c. 1225-1260), nave (c. 1308-c. 1370), and west façade (c. 1380-1420). </p><p>The thesis begins with a description of the destroyed buildings that occupied the site during the Saxon and Romanesque periods. The remainder of the dissertation focuses on the work completed at the Minster during the fourteenth century, in the so-called Decorated style. First, the nave is analyzed and its construction is assigned to six campaigns between the years c. 1308-c. 1370. Much discussion is devoted to the "historicism" of the nave's conservative design, which is a subtly modernized version of the east end that preceded it. Contemporary documents also permit discussion of the financial contributions of the laity, canons, and municipal leaders who paid for the nave to be built. </p><p>Finally, a detailed analysis is offered for the furnishings made at Beverley between 1292 and c. 1340: the reredos (high altar screen), sedilia (seating for priests), and the destroyed shrine which once contained the relics of St. John of Beverley. Like the nave, they are all neglected masterpieces of the Decorated style.</p> / Dissertation

This thesis describes the synthesis of a low modulus, thermally conductive thermal interface materials (TIM) using metal decorated nanotubes as fillers. TIMs are very important in electronics because they act as a thermally-conductive medium for thermal transfer between the interface of a heat sink and an electronic package. The performance of an electronic package decreases with increasing operating temperature, hence, there exists a need to create a TIM which has high thermal conduction to reduce the operating temperature. The TIM in this study is made from metal decorated multi-walled carbon nanotubes (MWCNT) and Vinnapas®BP 600 polymer. The sample was functionalized using mild oxidative treatment with nitric acid (HNO3) or, with N-Methly-2-Pyrrolidone (NMP). The metals used for this experiment were copper (Cu), tin (Sn), and nickel (Ni). The metal nanoparticles were seeded using functionalized MWCNTs as templates. Once seeded, the nanotubes and polymer composites were made with or without sodium dodecylbenzene sulfonate (SDBS), as a surfactant. Thermal conductivity (k) measurement was carried out using ASTM D-5470 method at room temperature. This setup best models the working conditions of a TIM. The TIM samples made for this study showed promise in their ability to have significant increase in thermal conduction while retaining the polymer’s mechanical properties. The highest k value that was obtained was 0.72 W/m-K for a well dispersed aligned 5 wt percent Ni@MWCNT sample. The Cu samples underperformed both Ni and Sn samples for the same synthesis conditions. This is because Cu nanoparticles were significantly larger than those of Ni and Sn. They were large enough to cause alloy scattering and too large to attach to the nanotubes. Addition of thermally-conductive fillers, such as exfoliated graphite, did not yield better k results as it sunk to the bottom during drying. The use of SDBS greatly increased the k values of the sample by reducing agglomeration. Increasing the amount of metal@MWCNT wt percent in the sample had negative or no effect to the k values. Shear testing on the sample shows it adheres well to the surface when pressure is applied, yet it can be removed with ease.

Vestiges fragiles et longtemps mésestimés, les empreintes constituent une source précieuse d’informations concernant la fréquentation d’un site. Actuellement largement étudiées en contexte de plein air, elles le sont beaucoup moins en grotte, contexte dans lequel leur étude a connu son apogée entre les années 1970 et le début des années 2000. Ces dernières années, l’intérêt des préhistoriens pour l’ichnologie en milieu souterrain s’est de nouveau manifesté et s’est concrétisé par la reprise de l’étude des empreintes dans plusieurs grottes ornées. Notre étude s’inscrit dans cette dynamique et vise à contribuer à la recherche autour des empreintes à partir du registre karstique et à participer au renouvèlement de la discipline en Préhistoire. Notre intérêt s’est porté sur les empreintes des grottes de Fontanet (Ariège) et de Cussac (Dordogne), d’abord du point de vue de leur formation et de leur conservation au cours du temps, puis de leur contribution à la compréhension de l’appréhension du monde souterrain par l’Homme au Paléolithique.À travers des observations, inventaires, mesures in situ et un travail ex situ grâce aux outils d’imagerie tridimensionnelle, nous avons mené une étude morphologique et morphométrique des empreintes fossiles. La singularité des empreintes de pied de Cussac nous a, en outre, amené à développer une approche expérimentale afin d’appréhender les différents facteurs ayant pu influencer leur morphologie au moment de leur formation et après celle-ci (taphonomie, port de chaussant, autre ?). Ces expérimentations ont mis en évidence un impact du substrat et de sa remobilisation sur la morphologie générale et les dimensions de l'empreinte, ainsi que la préservation de détails comme les orteils. La réalisation d'empreintes à l'aide de chaussants expérimentaux a conduit de plus à envisager l'utilisation de ce type de protection dans la grotte. Notre approche à la fois pluri et interdisciplinaire permet d’affirmer l’unicité des grottes de Fontanet et de Cussac d’un point de vue ichnologique, archéologique et géomorphologique. Tandis qu’à Cussac, la présence humaine semble avoir été limitée (aller/s et retour/s) et avoir répondu à un objectif précis (réalisation des gravures et dépôts humains ?), à Fontanet, la fréquentation semble s’être inscrite dans la durée et a impliqué plusieurs catégories d’individus (présence de juvéniles) et des activités variées.Des comportements souterrains similaires et qui se retrouvent durant l’ensemble du Paléolithique sont aussi mis en évidence (exploration globale des cavités, etc.). Ces travaux se présentent alors comme une contribution essentielle aux discussions relatives à la fonction de ces deux cavités. / Tracks, which are among the most fragile and underestimated archaeological remains, represent a valuable source of information on site frequentation. In the past few years, they were widely studied in open air contexts. However, their analysis in caves, a context in which their study reached its peak between the 1970s and the early 2000s, is much less common. Recently, interest towards ichnology in subterranean environments re-emerged among prehistorians, and the study of tracks in several decorated caves was resumed. Our study is part of this dynamic and aims to contribute to research on tracks from the karst register and to participate in the renewal of the discipline in Prehistory. We study the footprints of the caves of Fontanet (Ariège) and Cussac (Dordogne), focusing firstly on their formation and conservation over time, and secondly on their contribution to the understanding of the subterranean environment appropriation by human in the Palaeolithic.Through observations, inventories, in situ measurements and ex situ work based on three-dimensional imaging tools, we conducted a morphological and morphometric study of fossil tracks. In addition, we have developed an experimental approach to understand the various factors that may have influenced the morphology of footprints at the time of their formation and since their formation. This multidisciplinary and interdisciplinary approach makes it possible to affirm the uniqueness of the Fontanet and Cussac caves from an ichnological, archaeological and geomorphological point of view and at the same time reveals similar behaviours that can be found throughout the Paleolithic period. The profile of individuals who have frequented these two cavities gradually takes shape. We propose several hypotheses concerning their behaviour and activities in this confined and naturally constraining space and contribute to the discussions relating to the function of these two cavities.

Ankara, being the capital, has been the most important city for the New Modern Turkish State on its way of establishing the modernity project of Turkey. The development of the urban planning projects proceeded on the basis of this aimed concept of the new society, carrying the privilege of being the symbol of the modern republic, prosperity and wealth. Ke&ccedil / i&ouml / ren is one of the main districts of Ankara. The main aim of this study is to analyze and describe the ideological departure of Ke&ccedil / i&ouml / ren from the concept of the &ldquo / modern&rdquo / Ankara, within the last ten years. Here the attitude of the municipality and its role as the agent of civil power leading the architectural and urban transformation of Ke&ccedil / i&ouml / ren from a district full of gecekondu to one full of &ldquo / decorated sheds&rdquo / will be discussed. Here, the term &ldquo / decorated shed&rdquo / , introduced by Robert Venturi, will be used for the explanation of the new architectural and urban elements Furthermore, the attitude of the society and the architects and contractors who are responsible for the actual case will be brought into argumentation. In this sense, other subsidiary terms will be used to explain the process of the case are / populism and politics, nationalism, the ideology of the Turkish nation (T&uuml / rkl&uuml / k), Turanism, Islamism and orientalism. Additionally, an important building in the district, the Estergon Castle, which has different characteristics from the other parts of the district, will be explained with the terms &ldquo / hyper-reality&rdquo / and &ldquo / kitsch&rdquo / by the explanations of Umberto Eco and Dorfles.

Made available in DSpace on 2015-05-14T12:14:07Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1512497 bytes, checksum: 049664bc02f2d2d336fd5fe2822b8458 (MD5) Previous issue date: 2013-03-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Granular decorated chains can be used for the development of impact-absorbing devices. Thus, one of the features of those systems is that they can be used as shock absorbers and impact protectors. We study here the pulse propagation in a decorated granular chain, composed of spherical grains, which initially are just touching each other, making use of an effective description, where the original chain was replaced by a decorated chain with effective masses where the grains interact via an effective potential. Our goal was to generalize the results obtained in a previous work, by analizing a decorated chain with an arbitrary number of small grains between the large ones, and thus, presenting an analytical approach that describes the effective masses and the effective interaction between the granules as a function of the quantity small grains between the large ones. In this system the grains interact with each other via the Hertz potential. We presented the comparation between of the numerical and analytical results for the profiles velocity of the large granules in the original chain with the grains of the effective chain, the pulse propagation time, and the frequency of oscillation of the smaller grains in the original chain. We also highlight the use of Binary Theory, which was been widely appllied to describe analitically the properties of the propagating pulse in granular chains. / Cadeias granulares decoradas podem ser usadas no desenvolvimento de aparelhos que visam absorver ondas de choque. Sendo assim, uma das características deste sistema ´e que eles podem ser usados como absorvedores de choque e na proteção contra impactos. Estudamos aqui a propagação de um pulso em uma cadeia granular decorada, composta de grãos esféricos, que inicialmente estão apenas se tocando, fazendo uso de uma descrição efetiva, onde a cadeia original decorada ´e substituída por uma cadeia não decorada com massas efetivas onde os grãos interagiam através de um potencial efetivo. Nosso objetivo foi generalizar os resultados obtidos em um trabalho anterior, analisando uma cadeia decorada com um número qualquer de grãos pequenos entre os maiores, e assim, apresentando uma abordagem analítica que descreve a massa efetiva e a interação efetiva entre os grãos em função da quantidade de grãos pequenos entre os maiores. Neste sistema os grãos interagem através do potencial de Hertz. Apresentamos a comparação entre os resultados numéricos e analíticos, para os perfis de velocidade dos grãos grandes da cadeia original com os grãos da cadeia efetiva, além da comparação do tempo de propagação do pulso, e a frequência de oscilação dos grãos menores na cadeia original. Destacamos também o uso da Teoria Binária, que tem sido bastante aplicada para descrever analiticamente as propriedades da propagação de um pulso em cadeias granulares.

No description available.

Ce travail est consacré à la céramique décorée du Néolithique ancien danubien des bassins du Rhin, de la Meuse et de la Seine. L’application de la méthode systémique à l’ensemble des décors archéologiquement reconstituables découverts dans cette zone a permis d’élaborer une grammaire décorative du Rubané de la zone occidentale. L’analyse grammaticale ainsi appliquée à chaque groupe régional constitue un travail inédit.Au cœur de notre recherche se situe la question du morcellement du territoire. Dès le Rubané moyen, un bloc septentrional s’étend de l’Escaut jusqu’au Neckar, tandis qu’au sud, le Rubané Moyen de Haute-Alsace se développe de la vallée de la Marne au Hegau, en passant par l’extrémité sud de la plaine du Rhin supérieur. Seule la Basse-Alsace occupe, lors du Rubané moyen, une place isolée au sein de la zone occidentale. Dans la seconde moitié du Rubané (étapes IV et V), la zone occidentale est morcelée en trois complexes : le Rubané du Nord-Ouest qui s’étend de l’Escaut au Main, le Rubané du Centre qui regroupe les zones du Palatinat et du Neckar et le Rubané du Sud qui englobe le sud de la plaine du Rhin supérieur (Basse- et Haute-Alsace) et le Bassin parisien. / This work is dedicated to the analysis of the decorated pottery of the early Danubian Neolithic (Lbk) in the basins of the Rhine, the Meuse and the Seine (western Lbk). The application of a systemic approach to all the reconstructible decorations discovered in this area permitteded the elaboration of a decorative grammar for the western Lbk area. This grammatical analysis, which was applied to all the regional groups of this area, constitutes a totally new work.The center of our research focuses with the regionalisation process. In the middle Lbk phase, a northern block spreads over the Escaut to the Neckar, whereas in the south the “middle Lbk from Haute-Alsace” goes from the valley of the Marne to the Hegau via the southern part of the higher Rhine plain. Only the Basse-Alsace region occupies an isolated place within the western Lbk. In the second half of the Lbk (steps IV and V) this area is divided into three complexes: the Northwest Lbk, from the Escaut to the Main, the central Lbk, comprising the Palatinat and the Neckar regions and the southern Lbk, which includes the south of the higher Rhine plain (Basse- and Haute-Alsace) and the Paris basin.