Mechanical Stability in Crystalline Silicon Solar Cells

Mechanical stability of back contact solar cells deteriorates when holes (MWT, EWT) or grooves (TWT) are created in the wafer. These operations are essential for these structures so we found necessary to quantify the magnitude of this damage. A set of wafers with the EWT structure was produced and its mechanical strength measured by the Ring on Ring bending test. Other two sets of wafers with similar processes were prepared and tested to compare the effect of different fabrication steps on mechanical strength of the wafer. A numeric model was developed to analyse the data from the Ring on Ring test and a statistical study was carried out

Adding pharmacogenomics to the development of new marine-derived anticancer agents

Nature has always been a highly productive tool in the development of anticancer therapies. Renewed interest in the potential of this tool has recently been sparked by the realization that the marine ecosystem can be used for the discovery and development of new compounds with clinical potential in advanced resistant tumors. These compounds can be incorporated into combination approaches in a chronic therapy scenario. Our marine anticancer program is using the sea to develop new agents with activity in resistant solid tumors and to identify new cellular targets for therapeutic intervention. This review describes the integration of different pharmacogenomic tools in the development of Yondelis™, Aplidin(® )and Kahalalide F, three marine-derived compounds currently in Phase II or III development. Our results are reinforcing the targeted selectivity of these agents and opening the gates for customized therapies in cancer patients in the near future

Collective bargaining, firm heterogeneity and unemployment

Comparamos el comportamiento del mercado laboral bajo negociación a nivel de empresa y a nivel de sector en una economía de tipo Mortensen-Pissarides con un sector y con perturbaciones específicas a la empresa. Nuestros resultados teóricos principales son dos. Primero, el desempleo es menor bajo negociación a nivel de empresa. Segundo, introducir descuelgue eficiente de los convenios sectoriales basta para reducir el desempleo a su nivel bajo negociación de empresa. Para una economía europea continental arquetípica, encontramos que la tasa de paro es aproximadamente 5 puntos porcentuales menor bajo negociación de empresa (o descuelgue eficiente) que bajo negociación sectorialWe compare labor market outcomes under firm-level and sector-level bargaining in a onesector Mortensen-Pissarides economy with firm-specific productivity shocks. Our main theoretical results are twofold. First, unemployment is lower under firm-level bargaining Second, introducing efficient opting-out of sector-level agreements suffices to bring unemployment down to its level under decentralized bargaining. For an archetypical contintental European calibration, we find that the unemployment rate is about 5 percentage points lower under frm-level bargaining or efficient opting out than under sector-level bargainin

Avanzando hacia la sostenibilidad en la industria extractiva: el caso de la Comunidad de Madrid

El concepto de sostenibilidad comienza a ser ampliamente utilizado desde que en 1987,Ia primera ministra noruega Gro Harlem Brundtland, en un informe presentado en la Comisión Mundial para el Medio Ambiente y el Desarrollo Sostenible lo define como"Aquel desarrollo que satisface las necesidades del presente sin comprometer la capacidad de las generaciones futuras para satisfacer sus propias necesidades" Este concepto de sostenibilidad, que ha dado origen a diversas interpretaciones, ha ido evolucionando desde una concepción puramente ecológica a otra mucho más amplia donde se recogen otros aspectos como los económicos y sociales. Efectivamente, el concepto de sostenibilidad en la actividad humana ha de entenderse como una conjugación de esas tres facetas o dimensiones: la ecológica, la social y la económica, ya que sin esta percepción el desarrollo humano quedaría prácticamente limitado a una actividad semiprimitiva, donde no se afecta al entorno pero tampoco se satisfacen las necesidades de la sociedad

Photovoltaic Modules Transient Response Analysis and Correction Under a Fast Characterization System

Failures of single photovoltaic (PV) modules lead to significant power losses in large PV systems. Individual and periodic monitoring of each PV module is a powerful way to detect these losses. Recently, a novel monitoring method, named Module to Module Monitoring System (M3S), has been proposed. This monitoring method, without disconnecting the PV module from the rest of the system, is able to produce and measure small variations around the operating point of the PV module. The entire measurement is performed in less than 5 ms, using only low-power components. For current high-efficiency PV modules, these short measurement times generate a hysteresis effect in the current-voltage (I-V) curve during the transient-state, which makes it difficult to directly estimate the static I-V characteristics of the PV module. In this work, the transient response of the PV module is analyzed and a methodology to correct the hysteresis effect and estimate the I-V characteristics is implemented. From the obtained dynamic measurements, the proposed methodology is able to estimate the I-V characteristics of the PV module around the operating point with a mean squared error below 0.8%.This work was supported by the Basque Country Government [Grant No. PRE_2016_1_0016] and [project Promise Elkartek 19/49]; and the Fundacion Iberdrola Espana [Convocatoria de ayudas a la Investigacion en Energia y Medio Ambiente 2018

Employment fluctuations in a dual labour market

Artículo de revist

La cofradía Mouride en la emigración senegalesa: ¿agente de desarrollo?

FAAEE, Federación de Asociaciones de Antrdel Estado Español; ASANA, Asociación Andaluza de Antropologí

Impact of extended contact co-firing on multicrystalline silicon solar cell parameters

During the temperature spike of the contact co-firing step in a solar cell process, it has been shown that the concentration of lifetime-killer dissolved metallic impurities increases, while adding an annealing after the spike getters most of the dissolved impurities towards the phosphorus emitter, where they are less detrimental. The contact co-firing temperature profile including the after-spike annealing has been called extended contact co-firing, and it has also been proposed as a means to decrease the emitter saturation current density of highly doped emitters, benefiting thus a wide range of materials in terms of detrimental impurity content. The aim of the present work is to determine the effect of performing this additional annealing on contact quality and solar cell performance, looking for an optimal temperature profile for reduction of bulk and emitter recombination without affecting contact quality. It presents the effect of the extended co-firing step on fill factor, series resistance and contact resistance of solar cells manufactured with different extended co-firing temperature profiles. Fill factor decreases when extended co-firing is performed. Series resistance and contact resistance increase during annealing, more dramatically when the temperature peak is decreased. Scanning Electron Microscopy (SEM) images show silver crystallites in contact with silver bulk before the annealing that allow a direct current path, and silver crystallites totally surrounded by glass layer (>100 nmthick) after annealing. Glass layer redistribution and thickening at low temperatures at the semiconductor-metal interface can be related to the series resistance increase. Degradation of series resistance during the temperature spike, when it is below the optimum one, can be also attributed to an incomplete silicon nitride etching and silver crystallite formation. To make full use of the beneficial effects of annealing, screen-printing metallic paste development supporting lower temperatures without thick glass layer growth is needed

A 3 terminal parallel connected silicon tandem solar cell

A new tandem structure based on a silicon solar cell is presented. This structure works with two or three junction levels, being the silicon cell in this last case the intermediate cell. The different levels have been interconnected in parallel and for that a greater number of the lower band gap cells would be needed in order to equalize the operating voltage of all the structure. However, the presented three terminals structure only needs a maximum of 4 pn junctions for the 3 levels structure or even only 2 for a two level structure. This structure can be easily included in a conventional 2 terminal flat module without complicating the internal wiring. The maximum technological efficiency has been estimated in 39.4% for the three levels structure and using well known materials for each level a 30 to 32% efficiency level sounds possible

CRB2 completes a fully expressed Crumbs complex in the Retinal Pigment Epithelium

The CRB proteins CRB1, CRB2 and CRB3 are members of the cell polarity complex Crumbs in mammals that together with Scribble and Par complexes stablish the polarity of a variety of cell types. Although many members of the Crumbs complex proteins are expressed in the retinal pigment epithelium (RPE), and even though the mRNA of CRB2 has been detected in ARPE-19 cells and in the RPE/Choroid, to date no CRB protein has yet been found in this tissue. To investigate this possibility, we generated an antibody that specifically recognize the mouse CRB2 protein, and we demonstrate the expression of CRB2 in mouse RPE. Confocal analysis shows that CRB2 is restricted to the apicolateral membrane of RPE cells, and more precisely, in the tight junctions. Our study identified CRB2 as the member of the CRB protein family that is present together with the rest of the components of the Crumbs complex in the RPE apico-lateral cell membrane. Considering that the functions of CRB proteins are decisive in the establishment and maintenance of cell-cell junctions in several epithelial-derived cell types, we believe that these findings are a relevant starting point for unraveling the functions that CRB2 might perform in the RPE.This study was supported by grants from Fundación Ramón Areces and Ministerio de Ciencia e Innovación (BFU2008-04490/BFI). S.H.M received support from the Junta de Castilla y León PhD Program.Peer Reviewe