Reliability evaluation of III-V concentrator solar cells

Concentrator solar cells have been proposed as an interesting way of reducing the cost of photovoltaic electricity. However, in order to compete with conventional solar modules it is necessary not only to reduce costs but also to evaluate and increase the present reliability. Concentrator solar cells work at higher temperature, solar radiation and current stress than conventional solar cells and a carefully reliability analysis is needed. In this paper a reliability analysis procedure, that is being developed, is presented

Politainment in the transmedia construction of the image of politicians

This article explores the application of the concept of transmedia narrative to the construction of the public image of political figures, in a media context characterised by the prevalence of infotainment and the dissolution of the boundaries of political content. To attain this objective, a case-study on a specific leader is carried out; he is a regional leader recognised at a national level thanks to his discursive strategy: president of Cantabria, Miguel Ángel Revilla, chosen for his role as a regular guest on T.V shows of all kinds, as well as for having become the third most followed Spanish politician on social networks. Through content analysis, we examine the character’s own performance on different media (television, social networks and an autobiographical book) along with the reactions provoked among the cybernauts. The results show a multiplatform narrative adapted to the specific formal language of each of those media and formats, constantly maintaining the application of politainment features (personalisation, entertainment, emotiveness and trivialisation of the issues). Regarding the effects, there is a high level of involvement and a love-hate dichotomy among the public, as proved in social networks. Consequently, in the transmedia political narrative (TPN) the users co-create the resulting image of the politician who is finally perceived by the audience. In addition, the success of Revilla’s communication strategy is verified via ensuring that the self-assigned values in his speech, such as leadership and closeness to the people, match those that the audience identify with his figure.El presente artículo explora la aplicación del concepto de narrativa transmedia a la construcción de la imagen pública de las figuras políticas en un contexto mediático dominado por el infoentretenimiento y la disolución de los límites del contenido político. Con este objetivo, se realiza un estudio de caso sobre un líder regional reconocido a nivel nacional gracias a su estrategia discursiva: el presidente de Cantabria, Miguel Ángel Revilla, elegido por su rol de invitado asiduo de programas televisivos de diversa índole y por haber conseguido ser el tercer político español con más seguidores en redes sociales. A través del análisis de contenido, se examina la producción propia del personaje en distintos medios (televisión, redes sociales y libro autobiográfico) y las reacciones que provoca en los cibernautas. Los resultados muestran un relato multiplataforma que se adapta al lenguaje formal de cada espacio manteniendo de forma constante la aplicación de los rasgos del politainment (personalización, entretenimiento, emotividad y frivolización de los temas). Por lo que refiere a los efectos, se observa una alta implicación de los públicos y una dicotomía de amor-odio que se evidencia en redes sociales. En consecuencia, en la narrativa política transmedia (NPT) los usuarios participan en la co-creación de la imagen final del político que percibe la audiencia. Además, se constata el éxito de la estrategia comunicativa de Revilla al conseguir que los valores que se asigna en su discurso, como liderazgo y cercanía con el pueblo, sean los que los receptores identifican con su figura

Unidades de manejo para Pinus taeda L. com base na análise de agrupamento.

Seção: Silvicultura e Produção de Biomassa

FMCW sparse array imaging and restoration for microwave gauging

The application of imaging radar to microwave level gauging represents a prospect of increasing the reliability of target detection. The aperture size of the used sensor determines the underlying azimuthal resolution. In consequence, when FMCW-based multistatic radar (FMCW: frequency modulated continuous wave) is used, the number of antennas dictates this essential property of an imaging system. The application of a sparse array leads to an improvement of the azimuthal resolution by keeping the number of array elements constant with the cost of increased side lobe level. Therefore, ambiguities occur within the imaging process. This problem can be modelled by a point spread function (PSF) which is common in image processing. Hence, an inverse system to the imaging system is needed to restore unique information of existing targets within the observed radar scenario. In general, the process of imaging is of ill-conditioned nature and therefore appropriate algorithms have to be applied. The present paper first develops the degradation model, namely PSF, of an imaging system based on a uniform linear array in time domain. As a result, range and azimuth dimensions are interdependent and the process of imaging has to be reformulated in one dimension. Matrix-based approaches can be adopted in this way. The second part applies two computational methods to the given inverse problem, namely quadratic and non-quadratic regularization. Notably, the second one exhibits an ability to suppress ambiguities. This can be demonstrated with the results of both, simulations and measurements, and enables sparse array imaging to localize point targets more unambiguously

Silver and Gold Nanoparticles Alter Cathepsin Activity In vitro

Nanomaterials are being incorporated into many biological applications for use as therapeutics, sensors, or labels. Silver nanomaterials are being utilized for biological implants and wound dressings as an antiviral material, whereas gold nanomaterials are being used as biological labels or sensors due to their surface properties and biocompatibility. Cytotoxicity data of these materials are becoming more prevalent; however, little research has been performed to understand how the introduction of these materials into cells affects cellular processes. Here, we demonstrate the impact that silver and gold nanoparticles have on cathepsin activity in vitro. Cathepsins are important cellular proteases that are imperative for proper immune system function. We have selected to examine gold and silver nanoparticles due to the increased use of these materials in biological applications. This manuscript depicts how both of these types of nanomaterials affect cathepsin activity, which could impact the host's immune system and its ability to respond to pathogens. Cathepsin B activity decreases in a dose-dependent manner with all nanoparticles tested. Alternatively, the impact of nanoparticles on cathepsin L activity depends greatly on the type and size of the material

Response of reverse convection to fast IMF transitions

The nature of the transition that high‐latitude reverse convection makes in response to fast interplanetary magnetic field (IMF) changes is investigated using observations from multiple spacecraft and a ground magnetometer array. We focused on two fast IMF‐transition events on 22 April 2006. Immediately after the first event, three ST5 spacecraft identified a clear change in the distribution of the polar cap field‐aligned current. Coordinate observations with the Greenland magnetometer chain showed that the near‐noon Hall current distribution, which is closely related to the polar cap field‐aligned current or reverse convection, was in a transition state for about 10 min. For the second event, the Greenland magnetic perturbations also showed that a transition state occurred in the near‐noon sector for 10–15 min. Three DMSP spacecraft that traversed the polar cap provided evidence showing that variations of the ground magnetic perturbations were produced by the transition from clockwise plasma circulation to the anticlockwise circulation over the polar cap. A simple calculation based on the Biot‐Savart law shows that the near‐noon transition state is consistent with the approach of a new convection region to the near‐noon sector at the speed of 0.5–1 km s–1, which is coupled with the moving away of the old convection region at a similar speed. For the higher‐latitude sunward flow region, it is found that the convection takes a transition state almost simultaneously (within 1 min) with that in the near‐noon sector, i.e., quasi‐instantaneous response.Key PointsTransition state with a timescale of ~10 min in the near‐noon polar cap for BZ > 0The state is consistent with the passage of old and new convection regionsAlmost simultaneous initial response in the upstream polar cap and the near noonPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111947/1/jgra51794.pd