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Oxidação eletroquímica de monóxido de carbono sobre nanopartículas de platina não suportadas e influência do suporte na atividade eletrocatalítica de eletrocatalisadores suportados / Electrochemical oxidation of carbon monoxide on unsupported platinum nanoparticles and the influence of the support in the electrocatalitic activity of supported electrocatalystsEduardo Gonçalves Ciapina 10 March 2010 (has links)
Este trabalho descreve um estudo da reação de oxidação eletroquímica de uma monocamada de monóxido de carbono (CO) adsorvido (Stripping de CO) sobre materiais eletrocatalíticos não suportados bem como a influência do suporte nas propriedades estruturais e eletroquímicas dos eletrocatalisadores suportados. Os eletrocatalisadores estudados foram platina (Pt) não suportada bem como Pt suportada em carbono Vulcan (Pt/C) e em óxidos de rutênio (Pt/RuO2) e estanho (Pt/SnO2). Os materiais foram caracterizados por Difratometria de Raios X (DRX), Espectroscopia por Dispersão de Energia de Raios X (EDX), Microscopia Eletrônica de Transmissão (MET) e Espectroscopia de Absorção de Raios X (XAS). Os resultados encontrados para duas amostras de Pt não suportada mostraram que os materiais são compostos de aglomerados de nanopartículas de Pt com cerca de 10 nm e revelam múltiplos picos de oxidação de CO em meio de ácido perclórico 0,1 mol L-1, tanto em condições potenciodinâmicas quanto potenciostáticas. Foi demonstrado que o stripping de CO potenciodinâmico pode fornecer evidências acerca do tamanho de partícula e que partículas maiores apresentam os menores sobrepotenciais para a reação em questão. A partir de experimentos de oxidação de CO sob condições potenciostáticas e com o auxílio de um modelo para a reação, foram encontrados os valores das constantes de velocidade para cada processo, cujo comportamento em função do potencial revelou diferenças entre os dois materiais estudados, o que também sugere mudanças no mecanismo da reação ou na isoterma de adsorção das espécies envolvidas. No caso dos eletrocatalisadores suportados Pt/C, Pt/RuO2 e Pt/SnO2, o suporte pode influenciar nas propriedades estruturais e eletrônicas, como evidenciado pelos experimentos de XAS, como também se apresentar como um co-catalisador para a reação de oxidação de CO, como encontrado para os materiais Pt/RuO2 e Pt/SnO2, visto que apresentaram menores sobrepotenciais para a oxidação de CO se comparados com Pt/C. Tal fato pode ser comprovado também por meio dos estudos nos quais Pt não suportada foi posteriormente ancorada nos diferentes suportes estudados, onde se destacou o material Pt + RuO2, que apresentou o menor sobrepotencial para a reação. De maneira comparativa, foi estudada a reação de oxidação de etanol sobre os catalisadores suportados e os resultados mostraram que os óxidos de rutênio e estanho aumentam as densidades de correntes amostradas a partir de saltos potenciostáticos. / This work describes a study of carbon monoxide monolayer electrochemical oxidation (CO stripping) on unsupported electrocatalysts as well as the influence of the support on the structural and electrochemical properties of the supported electrocatalysts. The materials studied comprised unsupported platinum (Pt) nanoparticles, Pt nanoparticles supported on high surface area carbon (Pt/C), and Pt nanoparticles supported on ruthenium oxide (Pt/RuO2) and on tin oxide (Pt/SnO2). All materials were characterized by X-Ray Diffraction (XRD), Energy Dispersive X-Ray Spectroscopy (EDX), Transmission Electron microscopy (TEM), and X-Ray Absorption Spectroscopy (XAS). The results for two samples of unsupported Pt nanoparticles revealed the materials are formed by agglomerates of Pt nanoparticles of about 10 nm with slight differences between the samples, and the CO stripping electrochemical oxidation in 0.1 mol L-1 HClO4 showed multiple oxidation peaks in both potentiodynamic and potentiostatic conditions. It was demonstrated that potentiodynamic CO stripping can give evidences about the particle size, in which larger particles present smaller overpotentials for the reaction. From potentiostatic CO electro-oxidation, aided by a mathematical model of the reaction, it was found the reaction rate constant for each process and its behavior as a function of the potential revealed differences between the two samples, also suggesting differences in the mechanism of the reaction or in the adsorption isotherm for the involved species. In the case of the supported electrocatalysts Pt/C, Pt/SnO2, and Pt/RuO2, the support seems to influence in the structural and electronic properties, as probed by XAS experiments, as well as to participate as a co-catalyst in the CO oxidation, as in the case of Pt/SnO2 and Pt/RuO2, once they presented lower overpotentials for CO oxidation if compared to Pt/C. This fact was also confirmed by studies using mixtures of unsupported Pt nanoparticles and the different supports described, in which the system Pt + RuO2 presented the lowest overpotential for the reaction. From a comparative point of view, ethanol electrochemical oxidation was also investigated on the different prepared materials and the results showed that RuO2 and SnO2 as the catalyst supports increase the current density at a given potential in the potential step experiments.
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Naloxone: The State of Co-Prescribing and Co-DispensingHagemeier, Nicholas E. 16 February 2018 (has links)
No description available.
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A composer-teacher in context: Music for the performing arts faculty in a New Zealand secondary schoolJennings, Janet January 2008 (has links)
This thesis examines the processes and outcomes of a composer-teacher's practice in the context of a New Zealand secondary school. The research was undertaken by the composer-teacher/researcher as a case study that integrates an investigation of the context with four action research music composition projects developed as a creative response to that context. Chapters One to Three comprise the background theory. Chapter One provides an introduction and overview of the research; Chapter Two explains and justifies the research methods. Chapter Three peels away and examines five layers of the secondary school context identified as significant in shaping the perceptions of the participants: approaching the context in a multi-layered way enabled coherent synthesis and appraisal of the relevant literature. Chapters Four to Seven comprise the four action research music composition projects. Each action research project focuses on a music score composed by the composer-teacher/researcher for a specific group of students at Macleans College, Auckland. The composition, production, and performance processes are investigated from the perspectives of all the participants. Each music project comprises a four part progression - plan (composition process), data (music score), data analysis (recordings of performances, surveys, and interviews with all participants) and reflection (feedback, and feedforward into the next project). Each phase of the research generated significant outcomes, such as the four original music scores. Chapter Eight summarizes the themes, issues, and patterns that emerged, and makes recommendations for further research. A model of co-constructive practice emerges from this research: teacher and students co-construct artistic worlds through performance. The model is not new (it is common practice, adopted by generations of musician-teachers) but is rarely acknowledged and currently un-researched. This research demonstrates the validity of the practice from both musical, and teaching and learning perspectives, and examines the strengths and limitations of the model. At its best, the creative processes co-constructed by a teacher with her students are shown to provide a crucible within which intense and creative learning experiences occur. Students of all levels of ability are shown to gain confidence in this context, and subsequently develop skills with apparent ease. The co-constructive model is limited in that it cannot meet the musical needs of all students: co-construction should be considered as one model of practice, appropriate for use in association with many others. This research provides 'virtual access' to a particular world of performance practice, revealing the secondary school context as a realm of authentic and valid musical practice.
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Asian multinational Companies’ Co-Branding as Brand StrategiesChoi, Yong Chul January 2009 (has links)
<p>Asian companies have turned to be multinationals. Many factors could be the reasons of this phenomenon, these days, cooperation strategies, especially, co-branding is an issue. Therefore, this study pursues to study which contexts Asian companies face and how Asian firms use co-branding. This study will study three cases: LG-PRADA, Sony-Ericsson, and Lenovo-IBM of co-branding. This research will analyze each case company’s portfolio with regional matrix and study how company use co-branding with co-branding typology. After reading this paper, readers can have an integrative view over Asian companies’ contexts and its co-branding strategy as its growth strategies.</p>
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Asian multinational Companies’ Co-Branding as Brand StrategiesChoi, Yong Chul January 2009 (has links)
Asian companies have turned to be multinationals. Many factors could be the reasons of this phenomenon, these days, cooperation strategies, especially, co-branding is an issue. Therefore, this study pursues to study which contexts Asian companies face and how Asian firms use co-branding. This study will study three cases: LG-PRADA, Sony-Ericsson, and Lenovo-IBM of co-branding. This research will analyze each case company’s portfolio with regional matrix and study how company use co-branding with co-branding typology. After reading this paper, readers can have an integrative view over Asian companies’ contexts and its co-branding strategy as its growth strategies.
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Attityd på köpet? : Om unga konsumenter och co-brandingSjöqvist, Linnea, Edman, Hanna January 2012 (has links)
I dagens samhälle finns reklam överallt och de flesta innehar en attityd gentemot både reklam och de varumärken som florerar i den, vare sig den är omedveten eller medveten. En målgrupp som ses som lättpåverkad, men ändå har en stark medvetenhet om olika varumärken är ungdomar. Som ung gäller det att passa in men ändå stå ut, att hitta sig själv trots grupptryck och påtryckningar från omvärlden. En inte obetydlig del av detta inflytande kommer från olika sorters marknadsföring som alla utsätts för varje dag. Denna studie ämnar undersöka ungdomars attityd till olika varumärken och hur attityden till enskilda varumärken kan påverka samarbete i form av co-branding, men även hur den upplevda passningen kan påverka resultatet. Respondenterna är elever på Skärgårdsgymnasiet i Åkersberga och med snöbollsmetoden som urval har 24 semistrukturerade intervjuer genomförts. De medverkande har fått ge sin åsikt om fyra olika varumärken, två företag och två personer. Därefter har de fått se en reklamfilm där ett företag och en person har ingått i ett samarbete och slutligen har respondenterna återgett sin attityd igen angående varumärken, samarbete och hur väl de anser att varumärkena passar ihop. Studiens resultat visar hur faktorer som en positiv eller negativ attityd drastiskt kan förändras av att de varumärken som ingår i alliansen inte passar ihop i respondenternas ögon. Positiv attityd överförs i viss grad, men även fall där de två delarna sågs som negativa kunde efter avslöjandet om samarbete ge respondenterna en positiv attityd. Tillsammans med tidigare forskning inom området co-branding kan uppsatsen tillföra ytterligare kunskap i denna forskning om konsumenters attityd gentemot varumärken.
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Value co-creation in the B2C context : An investigation of retailers’ and customers’ collaborationOsnes, Tone-Lise, Schmitz, Annika January 2012 (has links)
Problem: In today’s business markets companies are faced with new challenges occurring from globalization, new technologies, deregulation, blurring borders between industries, and outsourcing which change the competitive environment in the market. To deal with these challenges organizations are forced to look for new and innovative ways to differentiate themselves from competitors and to satisfy customers’ demands for more customized products and services. Additionally, nowadays customers strive for fulfilling their needs by being more active. Value co-creation, the collaboration between companies and customers, is as a solution of current interest to cope with these challenges. Due to the close linkage between retailers and customers, value co-creation is of high interest for this part of the SC. Hence, this thesis focuses on the retailer-customer context and co-creation in terms of co-designing of bikes. Purpose: The purpose of this Master of Science thesis is to investigate how and why retailers and customers co-create value. Therefore, retailers’ and customers’ potential motivators, the interaction between them and the actors’ potential outcomes are explored. Method: This thesis conducts an exploratory and qualitative investigation of three case companies; Bike by Me, myownbike, and 718 Cyclery. The empirical material is gathered from interviews with the CEOs of the three companies, the retailers’ customers, and potential customers. The findings have been analyzed using a framework developed based on existing literature, stated in the frame of reference, which is improved by this thesis’ findings. Conclusions: Customers and retailers co-create value due to different potential motivators and outcomes. Retailers are motivated by aspects such as increases in competitive advantage, differentiation, customer loyalty, and better understanding of new needs. Customers’ motivators are amongst others the product itself, individuality, and enjoyment. As retailers’ outcomes increased efficiency and effectiveness, new customer acquisition, and the establishment of long-term relationships are identified. Customers’ outcomes are high customer satisfaction, new knowledge, convenience, and financial aspects. Actions between retailers and customers in value co-creation are identified through a learning phase and an innovation phase. The retailer participates through providing information, the platform for co-creation, and suggestions and assistance. The customers collaborate in terms of designing the product, expression of desires and experiences, feedback, and WOM in interaction with other customers.
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The effects of Tiffany&Co’s online advertising strategy on brand perception in Italy and United StatesBosco, Urszula Petra Bianca 25 June 2012 (has links)
This Professional Report explores the effects of Tiffany&Co’s online advertising strategy on brand perception in Italy and United States. The study starts with an analysis of the concept of luxury and the opinion that scholars have on how luxury value and brand equity should be communicated. Brand perception, its influence on consumers, and the role of Internet are also analyzed. The last part includes a detailed analysis of the findings for Italian and American consumers aged 18-25 and the variables that influence Tiffany&Co’s perceptions. The study concludes with recommendations to reinforce brand equity and perceptions via online advertisements. / text
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Experimental study of convective dissolution of carbon dioxide in porous mediaLiang, Yu, active 21st century 03 February 2015 (has links)
Geological carbon dioxide (CO₂) capture and storage in geological formations has the potential to reduce anthropogenic emissions. The viability of technology depends on the long-term security of the geological CO₂ storage. Dissolution of CO₂ into the brine, resulting in stable stratification, has been identified as the key to long-term storage security. The dissolution rate determined by convection in the brine is driven by the increase of brine density with CO₂ saturation. Here we present a new analog laboratory experiment system to characterize convective dissolution in homogeneous porous medium. By understanding the relationship between dissolution and the Rayleigh number in homogeneous porous media, we can evaluate if convective dissolution occurs in the field and, in turn, to estimate the security of geological CO₂ storage fields. The large experimental assembly will allow us to quantify the relationship between convective dynamics and the Rayleigh number of the system, which could be essential to trapping process at Bravo Dome. A series of pictures with high resolution are taken to show the existence and movement of fingers of analog fluid. Also, these pictures are processed, clearly showed the concentration of analog fluid, which is essential to analyze the convective dissolution in detail. We measured the reduction in the convective flux due to hydraulic dispersion effect compared to that in homogeneous media, to determine if convective dissolution is an important trapping process at Bravo Dome. / text
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Carbon dioxide and water emulsion stability and rheology with nonionic hydrocarbon surfactants or particlesAdkins, Stephanie Sue 21 April 2015 (has links)
For the first time the interfacial properties of nonionic hydrocarbon surfactants at both the air-water and CO₂-water interfaces are investigated in terms of surfactant structure to determine the changes in surfactant efficiency (negative of the logarithm of the surfactant concentration to create a surface pressure of 20 mN/m). At the air-water interface, linear surfactant tails are more efficient due to the higher packing ability of the straight chains in the dense surfactant monolayer. However, at the CO₂-water interface, surfactant adsorption is small and tails can be solvated. Thus, branching which increases both tail solvation and tail hydrophobicity also enlarges the hard disk area of the surfactant to ultimately increase the efficiency of the surfactant at the CO₂-water interface. CO₂-in-water concentrated emulsions (foams) are studied over short and long times to evaluate the foam stability as a function of both surfactant structure and foam conditions using in-situ optical microscopy. The surface pressure measured at the CO₂- water interface is correlated with the short time stability of coalescing foams with very small cell sizes (under 0.4 [mu]m in diameter). Long time stability of bubbles to coalescence is shown under a variety of conditions. The rheology of these bulk CO₂-in-water foams under high-pressure conditions are also evaluated through measurements of the pressure drop over a capillary tube. Viscosities in excess of 200 cP are measured, an increase of over 1000 time that of pure CO₂ (0.09 cP at 24 °C and 2000 psia). The viscosity of the C/W foams are found to correlate with bubble size, continuous phase viscosity, shear rate, and interfacial tension. Hydrophobic silica particles adsorbed at the interface are also used to stabilize water-in-CO₂ emulsions as an alternative to surfactant stabilizers. The difficulties of tail solvation associated with many hydrocarbon surfactants in CO₂ can be removed by using particles instead of surfactant. A porous cross-linked shell is formed about the hydrophilic (colloidal and fumed) silica to render the particles CO₂-philic and the crosslinking removes ligand tails from the particle surface. / text
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