153 research outputs found

    Cu nanoparticles enable plasmonic-improved silicon photovoltaic devices

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    This work examines the effect of copper nanoparticles (Cu NPs) on the photocurrent efficiency of silicon photovoltaic (Si PV) devices. An optimized synthesis of stable Cu NPs is reported together with a procedure for their immobilization on the Si PV surface. A comprehensive analysis of the photocurrent and power dependence of the Cu NPs surface coverage and size is presented. A decrease in photoconversion was observed for wavelengths shorter than similar to 500 nm, due to the Cu interband absorption. In the low surface coverage limit, where the level of aggregation was found to be low, the surface plasmon resonance absorption dominates leading to a modest effect on the photocurrent response. As the number of aggregates increased with the surface coverage, the photocurrent efficiency also increased, and a maximum enhancement power conversion of 16% was found for a 54 +/- 6 NPs per mu m(2) PV cell. This enhancement was attributed to SPR light scattering and trapping into the Si PV device. Higher surface coverage yielded numerous aggregates which acted as a bulk coating and caused a decrease in both photocurrent and power measurements.Department of Foreign Affairs and International Trade Canada (DFAIT) through the Emerging Leaders in the Americas (ELAP) programDepartment of Foreign Affairs and International Trade Canada (DFAIT) through the Emerging Leaders in the Americas (ELAP) programCIAMFAPESP programCIAM-FAPESP programCNPqCNPqNSERCNSERCUniversity of VictoriaUniversity of Victori

    Som, sentido e paisagem sonora n'A cidade e as serras: análise de uma reportagem radiofónica

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    Dissertação apresentada à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Jornalismo.Dos três meios de comunicação tradicionais, a rádio apresenta-se como aquele em que a investigação académica é quantitativamente menos significativa. Esta constatação é verdadeira para o panorama nacional, mas também internacional. As análises denotam uma maior preponderância para o aprofundamento de estudos relativos à informação que é veiculada pelo meio radiofónico, mas pouco interesse tem existido para a questão da relação criativa implicada entre o ouvinte e o som. A presente dissertação tem como principal objectivo destacar o poder da sonoplastia no desencadear de uma multiplicidade de significações. Desta forma, pretende-se explorar a estética sonora de uma reportagem radiofónica sem nunca esquecer o modo como o som complementa a palavra falada. Para tal, analisar-se-á a peça A Cidade e as Serras, da autoria de João Paulo Guerra, construída com base num dos últimos romances de Eça de Queirós. Ao nível sonoro, o enfoque desta investigação privilegiará não só a abordagem da terminologia específica que fundamenta o termo soundscape, mas também a sua aplicabilidade ao jornalismo radiofónico e sobretudo o modo como a riqueza da prosa queirosiana foi preservada e simultaneamente convertida em paisagem sonora

    Head & Neck Oncology: purpose, scope and goals-charting the future

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    For many years now there has been a growing frustration with the statistics of head and neck cancer. Despite the many advances in diagnosis and therapy, there has been little change in the prognosis for most cancers of the head and neck in the last 50 years, so what is the point of yet another journal? Well, it is not all bad news

    Dinosaur Speed Demon: The Caudal Musculature of Carnotaurus sastrei and Implications for the Evolution of South American Abelisaurids

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    In the South American abelisaurids Carnotaurus sastrei, Aucasaurus garridoi, and, to a lesser extent Skorpiovenator bustingorryi, the anterior caudal ribs project at a high dorsolateral inclination and have interlocking lateral tips. This unique morphology facilitated the expansion of the caudal hypaxial musculature at the expense of the epaxial musculature. Distinct ridges on the ventrolateral surfaces of the caudal ribs of Aucasaurus garridoi are interpreted as attachment scars from the intra caudofemoralis/ilio-ischiocaudalis septa, and confirm that the M. caudofemoralis of advanced South American abelisaurids originated from a portion of the caudal ribs. Digital muscle models indicate that, relative to its overall body size, Carnotaurus sastrei had a substantially larger M. caudofemoralis than any other theropod yet studied. In most non-avian theropods, as in many extant sauropsids, the M. caudofemoralis served as the primary femoral retractor muscle during the locomotive power stroke. This large investment in the M. caudofemoralis suggests that Carnotaurus sastrei had the potential for great cursorial abilities, particularly short-burst sprinting. However, the tightly interlocking morphology of the anterior caudal vertebrae implies a reduced ability to make tight turns. Examination of these vertebral traits in evolutionary context reveals a progressive sequence of increasing caudofemoral mass and tail rigidity among the Abelisauridae of South America

    The Analysis of Nuclear Magnetic Resonance Spectra.

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    Molecular tools to distinguishes the two ecotypes of uncinula necator

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    *INRA Erist Bordeaux Diffusion du document : INRA Erist BordeauxNational audienc
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