527 resultados para Bains de soleil


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The inverter in a photovoltaic system assures two essential functions. The first is to track the maximum power point of the system IV curve throughout variable environmental conditions. The second is to convert DC power delivered by the PV panels into AC power. Nowadays, in order to qualify inverters, manufacturers and certifying organisms use mainly European and/or CEC efficiency standards. The question arises if these are still representative of CPV system behaviour. We propose to use a set of CPV – specific weighted average and a representative dynamic response to have a better determination of the static and dynamic MPPT efficiencies. Four string-sized commercial inverters used in real CPV plants have been tested.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Concentrator solar cell front-grid metallizations are designed so that the trade-off between series resistance and shading factor (SF) is optimized for a particular irradiance. High concentrator photovoltaics (CPV) typically requires a metallic electrode pattern that covers up to 10% of the cell surface. The shading effect produced by this front electrode results in a significant reduction in short-circuit current (I SC) and hence, in a significant efficiency loss. In this work we present a cover glass (originally meant to protect the cell surface) that is laser-grooved with a micrometric pattern that redirects the incident solar light towards interfinger regions and away from the metallic electrodes, where they would be wasted in terms of photovoltaic generation. Quantum efficiency (QE) and current (I)-voltage (V) characterization under concentration validate the proof-of-concept, showing great potential for CPV applications

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Multijunction solar cells (MJSC) use anti-reflective coatings (ARC) to minimize Fresnel reflection losses for a family of light incidence angles. These coatings adapt the refractive index of the cell to that of the surrounding medium. Patterns with sizes in the range of the light wavelength can be used to further reduce reflections through diffraction. Transparent nanopatterns with a gradual profile, called moth-eye nanostructures, can adapt the refractive index of the optical interfaces (often with n∼1.5) used to encapsulate concentrator solar cells to that of the air (n air∼1). Here we show the effect of a nanometric moth-eye ARC with a round motif deposited on commercial MJSC that achieves short-circuit current (I SC) gains greater than 2% at normal incidence and even higher in the case of tilted illumination. In this work, MJSC with different moth-eye ARC are characterized under quantum efficiency (QE) as well as under concentrated illumination I-V in order to assess their potential. Simulations based on coupled wave analysis (RCWA) are used to fit the experimental results with successful results.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Este trabalho enfoca a ação de patrocínio a eventos como ferramenta comunicacional, incorporada ao composto da comunicação de marketing. O principal objetivo é analisar e apresentar como as empresas usam e articulam as ferramentas da comunicação integrada de marketing às ações de patrocínio para se criar um efeito sinérgico de comunicação. A metodologia constitui-se em pesquisa bibliográfica e documental e o estudo de casos envolvendo as empresas Ambev, Petrobras e Bradesco com o patrocínio aos respectivos eventos: Skol Beats; Jogos Pan-americanos 2007 e o Espetáculo Saltimbanco do Cirque du Soleil, verificando como os aspectos teóricos foram apropriados em cada caso. As conclusões apontam, principalmente, que as empresas vêm buscando utilizar o potencial máximo de comunicação dos eventos não só ao promoverem, mas também na condição de patrocinadoras, e que o patrocínio deve ser parte de um plano integrado, no qual as ações estratégicas de comunicação de marketing, através das várias ferramentas que as constituem, podem e devem ser conjugadas para alcançar sinergia e valorizar as ações comunicacionais dos patrocinadores.(AU)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Este trabalho enfoca a ação de patrocínio a eventos como ferramenta comunicacional, incorporada ao composto da comunicação de marketing. O principal objetivo é analisar e apresentar como as empresas usam e articulam as ferramentas da comunicação integrada de marketing às ações de patrocínio para se criar um efeito sinérgico de comunicação. A metodologia constitui-se em pesquisa bibliográfica e documental e o estudo de casos envolvendo as empresas Ambev, Petrobras e Bradesco com o patrocínio aos respectivos eventos: Skol Beats; Jogos Pan-americanos 2007 e o Espetáculo Saltimbanco do Cirque du Soleil, verificando como os aspectos teóricos foram apropriados em cada caso. As conclusões apontam, principalmente, que as empresas vêm buscando utilizar o potencial máximo de comunicação dos eventos não só ao promoverem, mas também na condição de patrocinadoras, e que o patrocínio deve ser parte de um plano integrado, no qual as ações estratégicas de comunicação de marketing, através das várias ferramentas que as constituem, podem e devem ser conjugadas para alcançar sinergia e valorizar as ações comunicacionais dos patrocinadores.(AU)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Carbon-isotope stratigraphy has proven to be a powerful tool in the global correlation of Cretaceous successions. Here we present new, high-resolution carbon-isotope records for the Global Boundary Stratotype Section and Point (GSSP) of the Maastrichtian stage at Tercis les Bains (France), the Bottaccione and Contessa sections at Gubbio (Italy), and the coastal sections at Norfolk (UK) to provide a global d13C correlation between shelf-sea and oceanic sites. The new d13C records are correlated with d13C-stratigraphies of the boreal chalk sea (Trunch borehole, Norfolk, UK, Lägerdorf-Kronsmoor-Hemmoor section, northern Germany, Stevns-1 core, Denmark), the tropical Pacific (ODP-Hole 1210B, Shatsky Rise) and the South Atlantic and Southern Ocean (DSDP Hole 525A, ODP Hole 690C) by using an assembled Gubbio d13C record as a reference curve. The global correlation allows the identification of significant high-frequency d13C variations that occur superimposed on prominent Campanian-Maastrichtian events, namely the Late Campanian Event (LCE), the Campanian-Maastrichtian Boundary Event (CMBE), the mid-Maastrichtian Event (MME), and the Cretaceous-Paleogene transition (KPgE). The carbon-isotope events are correlated with the geomagnetic polarity scale recalculated using the astronomical 40Ar/39Ar calibration of the Fish Canyon sanidine. This technique allows the evaluation of the relative timing of base occurrences of stratigraphic index fossils such as ammonites, planktonic foraminifera and calcareous nannofossils. Furthermore, the Campanian-Maastrichtian boundary, as defined in the stratotype at Tercis, can be precisely positioned relative to carbon-isotope stratigraphy and the geomagnetic polarity timescale. The average value for the age of the Campanian-Maastrichtian boundary is 72.1 ± 0.1 Ma, estimated by three independent approaches that utilize the Fish Canyon sanidine calibration and Option 2 of the Maastrichtian astronomical timescale. The CMBE covers a time span of 2.5 Myr and reflects changes in the global carbon cycle probably related to tectonic processes than to glacioeustasy. The duration of the high-frequency d13C variations instead coincides with the frequency band of long eccentricity, indicative of orbital forcing of changes in climate and the global carbon cycle.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Contiene con portadilla y sign. propias : Tables des declinaisons du soleil ...

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Mode of access: Internet.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Mode of access: Internet.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Mode of access: Internet.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Mode of access: Internet.