Tuned liquid dampers simulation for earthquake response control of buildings

This paper is focused on the study of an earthquake protection system, the Tuned Liquid Damper (TLD), which can, if adequately designed, reduce earthquake demands on buildings. This positive effect is accomplished taking into account the oscillation of the free surface of a fluid inside a tank (sloshing). The behaviour of an isolated Tuned Liquid Damper, subjected to a sinusoidal excitation at its base, with different displacement amplitudes, was studied by finite element analysis. The efficiency of the TLD in improving the seismic response of an existing building, representative of modern architecture buildings in southern European countries was also evaluated based on linear dynamic analyses

Pathway Weathering in Granitoid Rocks from Central Region of Angola: Geochemical and Mineralogical Data

The Central Region of Angola is characterized by the abundance of granitoid rocks, whose weathering “in situ” originated the so-called residual soils. The textural, geochemical and mineralogical properties of these soils depend not only on the chemical composition of parent rock, but mainly on the local climatic and geomorphological characteristics. In the study area, sampling sites were selected, which extend from the region of Kwanza- Norte (Kassenda, Dondo) through Kwanza-Sul (Cangulo, Quibala and Waco Kungo) until the plateau of Huambo, where samples of fresh rock, weathered rock and its residual soil were collected along each weathering profile. Chemical analytical data were determined using X-ray fluorescence (XRF) analysis of the major and minor elements, whereas mineralogical data were determined using X-ray diffraction (XRD), on the samples of rock and on the respective residual soil. The results obtained and their comparative analysis between the sampling sites, as well as along each weathering profile is presented. This paper allows contributing to the knowledge of the geochemical weathering in tropical areas, as is the case of Angola

Cytomegalovirus Retinitis in an Immunocompromised Infant: A Case Report and Review of the Literature

Purpose: To describe a case of bilateral cytomegalovirus retinitis (CMVR) in an immunocompromised infant. Methods: A 4-month-old male infant with severe combined immunodeficiency syndrome was examined for the presence of CMVR. Ocular involvement was recorded and monitored by digital imaging. Results: The child had bilateral CMVR, with a fine granular pattern, present both in the peripheral retina and posterior pole. There was no vitritis. The active areas of retinitis progressively resolved with intravenous ganciclovir treatment. At the 3-month follow-up examination, no recurrence was observed. Conclusion: Ganciclovir treatment was effective in this case. The prognosis depends on rapid institution of effective antiviral therapy and on a patient’s systemic immunocompetence

Evaluation of eutrophication in the Ria Formosa coastal lagoon, Portugal

The Ria Formosa is a shallow mesotidal lagoon on the south coast of Portugal, with natural biogeochemical cycles essentially regulated by tidal exchanges at the seawater boundaries and at the sediment interface. Existing data on nutrients in the water column and the sediment, together with chlorophyll a and oxygen saturation in the water column,compared using different models for assessing eutrophication. The European Environmental Agency criteria are based on the comparison of nutrient concentrations which indicate that the situation in the Ria Formosa is ‘‘poor’’ to ‘‘bad’’. In contrast, the United States Estuarine Eutrophication Assessment is based on symptoms, including high chlorophyll a and low oxygen saturation, which indicate that the Ria Formosa is near pristine. Despite these contradictions, a preliminary assessment by Driving forces, Pressures, State, Impact, Reponses(DPSIR) of eutrophication demonstrate the potential for episodic eutrophic conditions from treated and untreated domestic effluent as well as from non-point source agricultural run off. Sediments are also an important source of nutrients in the lagoon, but their contribution to potential eutrophic conditions is unknown

Development and performance analysis of a metallic passive micro-direct methanol fuel cell for portable applications

Due to the growing interest on miniaturization for application on portable devices, the Micro Direct Methanol Fuel Cells (Micro-DMFC) proved to have great benefits. Passive fuel cells have extra advantages leading to less complex and cheaper systems. In the present work, an experimental study on the performance of a passive Micro-DMFC with an active area of 2.25 cm2 working at ambient conditions is described. Several commercially available materials for Membrane Electrode Assembly (MEA) are tested including materials with low platinum content to achieve lower prices. The effect of methanol concentration on the cell performance is evaluated. The performance is compared with the one obtained using an active Micro-DMFC with the same active area. A optimized design is proposed corresponding to a maximum power density, 19.2 mW/cm2, obtained using a Nafion 117 membrane, 3 mg/cm2 Pt–Ru and 0.5 mg/cm2 Pt as, respectively, anode and cathode catalyst loading, carbon paper as anode gas diffusion layer (GDL) and Sigracet carbon paper with micro porous layer (MPL) as cathode GDL at methanol feed concentration of 3 M. This result higher than the optimal power obtained with the active Micro-DMFC clearly demonstrates that membranes with low catalyst content could be used in passive MicroDMFC with success. This is an important result bearing in mind the use of micro-DMFCs in portable applications

Indicadores físicos da qualidade do solo no monitoramento da recuperação de clareiras da Província Petrolífera de Urucu, Amazonas.

O objetivo deste estudo é encontrar parâmetros indicativos da recuperação da qualidade da estrutura do solo

Método alternativo de colheita do guaraná.

Faz-se necessário um método alternativo de colheita que preconiza as operações de limpeza das ruas e coroamento das plantas para facilitar a coleta dos frutos caídos sob as plantas.bitstream/item/125086/1/Com-Tec-79.pd

Bounded rationality in decision making: Biases in managers of the Portuguese port sector

Decision-making is a multidisciplinary and ubiquitous phenomenon in organizations, and it can be observed at the individual, group, and organizational levels. Decision making plays, however, an increasingly important role for the manager, whose cognitive competence is reflected in his ability to identify potential opportunities, to immediately detect and solve the problems he faces, and to predict and prevent future threats. Nevertheless, to what extent do managers of the most diverse sectors continue to rely on false knowledge when they have better strategies at their disposal? The present article proposes the diagnosis of three prominent biases – overconfidence, optimism, and anchoring effect – in managers of the Portuguese port sector, as well as a comparative analysis with the conclusions already documented in relation to the Brazilian civil construction sector. In addition, this paper also provides a set of measures capable of contributing to the mitigation of the effects of these and other biases.info:eu-repo/semantics/publishedVersio