Reliability Improvement in III-V Concentrator Solar Cells by Means of Perimeter Protection

This paper presents the evolution in the strategy to assess the reliability of III-V solar cells and a new thermal ageing test carried out over GaAs single junction solar cells at three different temperatures (130, 150 and 170° C). The perimeter of the solar cells has been protected with silicone, which seems to be an effective way of enhancing the reliability of the solar cells. A preliminary analysis of the results indicates a mean time to failure (MTTF) one order of magnitude larger than the one obtained in a previous thermal test with the perimeter uncoated

Argentina’s Participation in the International Penal and Penitentiary Congress (1872-1950)

This article analyzes the participation of Argentine delegates in international prison congresses held between 1872 and 1950. We argue that the forms of participation can be divided into two. On the one hand, the presence of non-penitentiary experienced representatives, generally diplomats assigned to the places where the congresses were held. On the other hand, the participation of outstanding penitentiary specialists, both for their theoretical training (in Criminal Law) and for their daily management of the Argentinian prisons. For a better development, we will divide the article in two sections. In the first one, it will be dealt with from the first congress held in London (1872) to the sixth one held in Budapest (1905). In the second part, we will analyze from the seventh congress held in Washington (1910) to the last one held in The Hague (1950). It should be noted that for the preparation of this article we have used unpublished material located in the Archive of the Argentine Foreign Office and Ministry of Justice and Education; and other published texts.Fil: González, Esteban. Universidad de San Andrés; Argentina. Ministerio de Ciencia. Tecnología e Innovación Productiva. Agencia Nacional de Promoción Científica y Tecnológica; ArgentinaFil: Nuñez, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Investigaciones de Historia del Derecho; Argentina. Universidad de Buenos Aires; Argentin

Los viajes de estudio de Adolfo S. Carranza y la reforma penitenciaria en Tucumán (1911-1927)

El movimiento de reforma penitenciaria se caracterizó desde sus inicios por el carácter "viajero" de sus impulsores. Si bien podría elaborarse una larga lista de viajeros entre los reformistas, cabe mencionar, cuanto menos, al "padre" de la escuela penitenciaria clásica, John Howard (quien, a pesar de sus crónicos problemas de salud, recorrió gran parte de Europa para conocer sus instituciones de reclusión) y Alexis de Tocqueville quien fue comisionado por el gobierno francés a los Estados Unidos para estudiar su sistema penitenciario. A comienzos del siglo XX, en el marco de la reforma penitenciaria argentina, el jurista Adolfo S. Carranza (con una larga trayectoria en la provincia de Tucumán), retomó la senda viajera iniciada por John Howard, realizando varios viajes por Sudamérica (Chile y Brasil) y por Europa. En el presente trabajo nos proponemos reflexionar sobre una temática que ha sido escasamente abordada por la historiografía jurídica y social argentina: el papel de los "viajeros penitenciarios" y el impacto producido a posteriori en sus realidades locales a través de la adopción de instituciones extranjeras. Para ello, nos centraremos en el viaje realizado por Carranza a Europa en 1921 y en la construcción de la nueva Penitenciaría de Tucumán en el bienio 1925-1927.The penitentiary reform movement was characterized from its very beginning by its spearheads' "traveler" spirit. While a large list of travelers could be issued among reformists, the "fathers" of the penitentiary classic school should at least be mentioned. John Howard (who, in spite of his health chronic problems, traveled across Europe to know their detention institutions), and Alexis Tocqueville, who was commissioned by the French government to the United States to study their penitentiary system. At the beginning of the XX century, and within the framework of the Argentine penitentiary reform, the lawyer Adolfo S. Carranza (who held a large professional experience in the province of Tucumán), returned to the traveling pad initiated by John Howard, carrying out several trips to South America (Chile and Brazil) and to Europe. This paper aims to reflect on a subject which has been barely addressed by the argentine legal and social historiography: the role of the "penitentiary travelers" and the evaluation of the impact in their local contexts and realities after the events throughout the adoption of foreign institutions. Therefore we shall focus on the trip carried out to Europe by Carranza in 1921 and the building of the new Penitentiary of Tucumán in the biennium 1925-1927.Fil: González Alvo, Luis Gabriel. Universidad Nacional de Tucuman. Facultad de Filosofia y Letras. Instituto de Investigaciones Historicas "Dr. Ramon Leoni Pinto"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nuñez, Jorge Alberto. Instituto de Inv.de Historia del Derecho; Argentina. Instituto Max-Planck-para la Historia del Derecho Europeo; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

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

Comportamiento corrosivo de recubrimientos de Cr2O3 rociados térmicamente sobre acero al carbono en soluciones de cloruro

Cr2O3 coatings were deposited on carbon steel through the flame spraying technique using two types of flames (neutral and oxidizing). The protective and morphological characteristics of the coatings were determined. The coatings had layer thickness values of 114 and 214µm for oxidizing and neutral samples, respectively. Porosity percentages of 4.5 % and 2.5 % were determined, where the neutral sample presented the greatest porosity due to the insufficient fusion of the oxide particles during the process, resulting in the formation of a heterogeneous and less compact layer. Microcracks and pores were found on the surface and cross-section of the coatings, due to the thermal expansion generated during the solidification process. The coating protective capacity was evaluated by electrochemical techniques over 672 hours in a 3.5 %wt NaCl saline solution. The results evidenced that the coatings manufactured with the oxidizing flame presented more corrosion resistance compared to those prepared with the neutral flame. The corrosion products were more evident in the neutral flame coatings, because of the diffusion mechanisms from the substrate to the surface coating through the interconnected pores. Finally, the wettability of the sodium chloride solution in the Cr2O3 coatings was measured by the contact angle technique, finding that the oxidizing flame coatings exhibited a higher angle contact value (64.8°) in contrast to the neutral flame coatings (35°).Los recubrimientos de Cr2O3    fueron depositados en un acero al carbono a través de la técnica de rociado térmico, usando dos tipos de llamas (neutra y oxidante). Se determinaron las características protectoras y morfológicas de los recubrimientos. Los recubrimientos mostraron espesores de capa con valores de 114 y 214 µm para las muestras depositadas con llamas neutra y oxidante, respectivamente. Se determinaron los porcentajes de porosidad de 4,5 y 2,5 %, en donde la muestra que se depositó con la llama neutra presentó la mayor porosidad debido a una fusión insuficiente de las partículas de óxido durante el proceso, resultando en la formación de una capa menos compacta y heterogé- nea. Las microgrietas y los poros se encontraron en la superficie y en la sección trasversal de los revestimientos debido a la expansión térmica generada durante el proceso de solidificación. La capacidad protectora de los recubrimientos fue evaluada a partir de técnicas electroquímicas por 672 horas en una solución salina 3,5 %wt NaCl. Los resultados evidenciaron que los revestimientos ela- borados con la llama oxidante presentaron una mayor resistencia a la corrosión en comparación con aquellos elaborados con la llama neutra. Los productos de corrosión fueron más evidentes en los recubrimientos con llama neutra debido a los mecanismos de difusión desde el sustrato a la superficie recubierta a través de los poros interconectados. Finalmente, la humectabilidad de la solución de cloruro de sodio en los recubrimientos de Cr2O3  fueron medidos por medio de la técnica de ángulo de contacto, encontrando que los revestimientos de llama oxidante mostraron un mayor ángulo de contacto (64,8 °) en contraste con los recubrimientos de llama neutra (35 °)

A Model-Driven Approach to develop Rich Internet Applications

El objetivo principal del proyecto fue Explorar los beneficios de la aplicación del Desarrollo Dirigido por Modelos (MDD - Model-Driven Development) en el desarrollo de aplicaciones software de buena calidad, utilizando tecnologías actuales a nivel de capa de presentación.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

Statistical Calculation of the Main Reliability Functions of GaAs Concentrator III-V Solar Cells

This paper presents some of the results of a method to determine the main reliability functions of concentrator solar cells. High concentrator GaAs single junction solar cells have been tested in an Accelerated Life Test. The method can be directly applied to multi-junction solar cells. The main conclusions of this test carried out show that these solar cells are robust devices with a very low probability of failure caused by degradation during their operation life (more than 30 years). The evaluation of the probability operation function (i.e. the reliability function R(t)) is obtained for two nominal operation conditions of these cells, namely simulated concentration ratios of 700 and 1050 suns. Preliminary determination of the Mean Time to Failure indicates a value much higher than the intended operation life time of the concentrator cells