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The welding of dissimilar metals was carried out using a pulsed Nd: YAG laser to join DP1000 steel and an aluminum alloy 1050 H111. Two sheets of each metal, with 30 × 14 × 1 mm3, were lap welded, since butt welding proved to be nearly impossible due to the huge thermal conductivity differences and melting temperature differences of these materials. The aim of this research was to find the optimal laser welding parameters based on the mechanical and microstructure investigations. Thus, the welded samples were then subjected to tensile testing to evaluate the quality of the joining operation. The best set of welding parameters was replicated, and the welding joint obtained using these proper parameters was carefully analyzed using optical and scanning electron microscopes. Despite the predicted difficulties of welding two distinct metals, good quality welded joints were achieved. Additionally, some samples performed satisfactorily well in the mechanical tests, reaching tensile strengths close to the original 1050 aluminum alloy.

Textural, mineralogical and chemical parameters of clays belonging to the Upper Cretaceous ‘Argilas de Aveiro’ formation were determined and correlated, using geostatistical analysis, with some relevant geotechnical parameters. The data obtained made it possible to subdivide the region under study into distinctive sectors on the basis of geotechnical behaviour. Clay fraction content and composition control geotechnical parameters such as the expandability and the Atterberg plastic and liquid limits. A positive correlation was found between both expandability and the Atterberg plasticity index values and the total phyllosilicates, smectite, MgO and Al2O3. However, Atterberg plasticity index values were relatively independent of the diverse clay mineral assemblages.

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RESUMO:O Brasil é o maior produtor mundial de citros, com destaque para o Estado de São Paulo, maior produtor nacional. Recentes estudos mostram que a área irrigada de citros em São Paulo tem aumentado significativamente nos últimos anos. Porém, a falta de informações sobre o manejo eficiente da irrigação na cultura de citros é uma das principais dificuldades enfrentadas pelos produtores. Com o intuito de atender a essa necessidade, este trabalho teve como objetivos determinar a evapotranspiração de uma planta adulta de limeira-ácida 'Tahiti' (Citrus latifolia Tan.) e o coeficiente de cultivo (Kc) no período seco (outono-inverno), utilizando a técnica de lisimetria de pesagem. O experimento foi realizado na ESALQ/USP em Piracicaba -SP, em área irrigada por gotejamento, com plantas espaçadas de 7 x 4 m, sendo cada planta atendida por quatro pontos de molhamento no solo, distribuídos de forma equidistantes entre si. Foi realizado o monitoramento climático, utilizando estação meteorológica automatizada, e a determinação da evapotranspiração da cultura por lisímetro de pesagem. Durante o período de estudo, o Kc variou entre 0,82 e 1,18, e a ETc variou entre 1,2 e 5,6. PALAVRAS-CHAVE:irrigação localizada, evapotranspiração da cultura, coeficiente de cultivo. CROP COEFFICIENT OF ACID LIME TAHITI DURING AUTUMN-WINTER PERIOD DETERMINED BY WEIGHING LYSIMETER TECHNIQUE IN PIRACICABA -SP, BRAZILABSTRACT: Brazil is the largest world producer of citrus crop, with São Paulo state leading as the largest national producer. Recent studies show that irrigated areas of citrus in the state have been increasing significantly in the last few years. However, lack of information on irrigation management related to this crop is one of the main problems encountered by the farmers. In order to help solve the above problem, the objective of this work was to determine the evapotranspiration of acid lime adult plant variety ' Tahiti' (Citrus latifolia Tan.) and the crop coefficient during dry period (autumn -winter) using a weighing lysimeter technique. The experiment was carried out at ESALQ/USP in Piracicaba -SP, Brazil, in a drip irrigated area with plant spacing of 7 x 4 m. Each plant was supplied with four wetting equidistant emitters. The climatic data was obtained by the use of automated meteorological station and the crop evapotraspiration by the use of a weighting lysimeter. During the study period, Kc varied from 0.82 to 1.18, and Etc varied from 1.20 to 5.6.

El trabajo aquí desarrollado pretende ofrecer una nueva perspectiva para el estudio de los retablos Barrocos portugueses, incidiendo en la caracterización elemental del oro utilizado para el dorado y en la identificación de elementos característicos de su composición. En este sentido fueron analizados los retablos mayores de las iglesias de San Bento da Vitória, Santa Clara y San Francisco, localizados en la ciudad de Oporto. Los análisis cualitativos y semi cuantitativos fueron efectuados por microscopía óptica (OM) y microscopía electrónica de barrido con difracción de rayos X (SEM-EDS). El análisis de los resultados permitió identificar una aleación de oro/plata/cobre y la presencia de oro de gran pureza, entre 22 y 23 quilates.