999 resultados para hollow section joint
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The section at Cristo Rei shows sandy beds with intercalated clayey lenses (IVb division from the Lisbon Miocene series) that correspond to a major regression event dated from between ca. 17.6 and 17 Ma. They also correspond to a distal position (relatively to the typical fluviatile facies in Lisbon), nearer the basin's axis. Geologic data and paleontological analysis (plant fossils, fishes, crocodilians, land mammals) allow the reconstruction of environments that were represented in the concerned area: estuary with channels and ox-bows; upstream, areas occupied by brackish waters where Gryphaea griphoides banks developped; still farther upstream, freshwaters sided by humid forests and low mountain subtropical forests under warm temperate and rainy conditions, as well as not far away, seasonally dry environments (low density tree or shrub cover, or steppe).
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The Peniche section (Ponta do Trovão) in Portugal is presented as potential stratotype (GSSP) for the Pliensbachian/Toarcian boundary. The lithostratigraphic succession is described and the chronostratigraphy, based on ammonite assemblages, is presented; the change in foraminifera assemblages occurs later, only at the base of beds 16 (base of Semicelatum Subzone, Crosbeyi ? Horizon). An extensive bibliographical list of all scientific articles containing specific reference to this stratigraphic boundary, whether from the Lusitanian or Algarve basins, is also presented.
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The Pliensbachian/Toarcian boundary (Lower Jurassic) is well represented in the Lusitanian Basin (Portugal), mainly in the Peniche area, recorded by a marl/limestone series. Calcareous nannofossil assemblages are described herein, with the aim to contribute to the Toarcian GSSP definition. Marly samples were collected 3 m below and 7 m above this boundary and analysed for calcareous nannofossils. The main nannofossils observed were Biscutum finchii, B. grande, Calcivascularis jansae, Crepidolithus crassus, C. granulatus, C. impontus, Lotharingius hauffii, L. sigillatus, L. aff. L. velatus, Schizosphaerella spp. and Tubirhabdus patulus. This assemblage indicates that the Pliensbachian/Toarcian boundary in Peniche lies in the upper part of the NJ5b Subzone. Schizosphaerella and Lotharingius dominate the assemblage. The abundant occurrence of C. jansae and the common occurrence of B. grande indicate a strong Tethyan influence.
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The Peniche section has revealed moderately-to-well preserved calcareous nannofossil assemblages across the Pliensbachian/Toarcian boundary. This good record has allowed the proposition of a refined biostratigraphic scheme. The stage boundary, as defined by ammonites, is comprised within the NJ5b C. impontus (NW Europe; BOWN & COOPER, 1998) or the NJT5b L. sigillatus (Mediterranean Tethys; MATTIOLI & ERBA, 1999) nannofossil subzones. Since in the Lusitanian Basin a mixing of N- and S-Tethyan taxa is observed, both biozonation schemes can be applied. Some nannofossil events (mainly first occurrences) are observed earlier in Portugal than in other Tethyan settings. It is still unclear if these events are real first occurrences. A diversification phase occurred across the Pliensbachian/Toarcian boundary. This phase is well recorded at Peniche, where a change is observed passing from the Pliensbachian, when assemblages are dominated by muroliths, to the Toarcian showing assemblages where placoliths are abundant. A quantification of nannofossils per gram of rock shows that absolute abundances are the highest across the Pliensbachian/Toarcian boundary. Indeed, Peniche exhibits nannofossil abundances very high with respect to correlative levels in other Tethyan settings. The pelagic carbonate fraction (produced by nannofossils) is important in the marly hemi-couplets of Peniche. In some levels, nannofossils account for more than 50% of the total carbonate fraction.
Joint effects of salinity and the antidepressant sertraline on the estuarine decapod Carcinus maenas
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Concurrent exposure of estuarine organisms to man-made and natural stressors has become a common occurrence. Numerous interactions of multiple stressors causing synergistic or antagonistic effects have been described. However, limited information is available on combined effects of emerging pharmaceuticals and natural stressors. This study investigated the joint effects of the antidepressant sertraline and salinity on Carcinus maenas. To improve knowledge about interactive effects and potential vulnerability,experiments were performed with organisms from two estuaries with differing histories of exposure to environmental contamination. Biomarkers related to mode of action of sertraline were employed to assess effects of environmentally realistic concentrations of sertraline at two salinity levels. Synergism and antagonism were identified for biomarkers of cholinergic neurotransmission, energy production,anti-oxidant defences and oxidative damage. Different interactions were found for the two study sites highlighting the need to account for differences in tolerance of local ecological receptors in risk evaluations.
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The Chaves basin is a pull-apart tectonic depression implanted on granites, schists, and graywackes, and filled with a sedimentary sequence of variable thickness. It is a rather complex structure, as it includes an intricate network of faults and hydrogeological systems. The topography of the basement of the Chaves basin still remains unclear, as no drill hole has ever intersected the bottom of the sediments, and resistivity surveys suffer from severe equivalence issues resulting from the geological setting. In this work, a joint inversion approach of 1D resistivity and gravity data designed for layered environments is used to combine the consistent spatial distribution of the gravity data with the depth sensitivity of the resistivity data. A comparison between the results from the inversion of each data set individually and the results from the joint inversion show that although the joint inversion has more difficulty adjusting to the observed data, it provides more realistic and geologically meaningful models than the ones calculated by the inversion of each data set individually. This work provides a contribution for a better understanding of the Chaves basin, while using the opportunity to study further both the advantages and difficulties comprising the application of the method of joint inversion of gravity and resistivity data.
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Comunicação apresentada na 18th Conference International of Health Promotion Hospitals & Health Services "Tackling causes and consequences of inequalities in health: contributions of health services and the HPH network", em Manchester de 14-16 de april de 2010
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The power systems operation in the smart grid context increases significantly the complexity of their management. New approaches for ancillary services procurement are essential to ensure the operation of electric power systems with appropriate levels of stability, safety, quality, equity and competitiveness. These approaches should include market mechanisms which allow the participation of small and medium distributed energy resources players in a competitive market environment. In this paper, an energy and ancillary services joint market model used by an aggregator is proposed, considering bids of several types of distributed energy resources. In order to improve economic efficiency in the market, ancillary services cascading market mechanism is also considered in the model. The proposed model is included in MASCEM – a multi-agent system electricity market simulator. A case study considering a distribution network with high penetration of distributed energy resources is presented.
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The provision of reserves in power systems is of great importance in what concerns keeping an adequate and acceptable level of security and reliability. This need for reserves and the way they are defined and dispatched gain increasing importance in the present and future context of smart grids and electricity markets due to their inherent competitive environment. This paper concerns a methodology proposed by the authors, which aims to jointly and optimally dispatch both generation and demand response resources to provide the amounts of reserve required for the system operation. Virtual Power Players are especially important for the aggregation of small size demand response and generation resources. The proposed methodology has been implemented in MASCEM, a multi agent system also developed at the authors’ research center for the simulation of electricity markets.
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The lack of specific laboratorial diagnosis methods and precise symptoms makes the toxocariasis a neglected disease in Public Health Services. This study aims to determine the frequency of Toxocara spp. infection in children attended by the Health Public Service of Hospital Municipal de Maringá, South Brazil. To evaluate the association of epidemiological and clinical data, an observational and cross-section study was carried out. From 14,690 attended children/year aged from seven month to 12 years old, 450 serum samples were randomly collected from September/2004 to September/2005. A questionnaire was used to evaluate epidemiological, clinical and hematological data. An ELISA using Toxocara canis larval excretory-secretory products as antigen detected 130 (28.8%) positive sera, mainly between children from seven month to five years old (p = 0.0016). Significant correlation was observed between positive serology for Toxocara, and frequent playing in sandbox at school or daycare center (p = 0.011) and the presence of a cat at home (p = 0.056). From the families, 50% were dog owners which exposed soil backyards. Eosinophilia (p = 0.776), and signs and symptoms analyzed (fever p = 0.992, pneumonia p = 0.289, cold-like symptoms p = 0.277, cough p = 0.783, gastrointestinal problems p = 0.877, migraine p = 0.979, abdominal pain p = 0.965, joint pain p = 0.686 and skin rash p = 0.105) could not be related to the presence of anti-Toxocara antibodies. Therefore, two asthmatics children showed titles of 1:10,240 and accentuated eosinophilia (p = 0.0001). The authors emphasize the needs of prevention activities.
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OBJECTIVE: Describe implementation of a successful program to reduce doses (cefazolin 2 to 1 g) used for antimicrobial prophylaxis. METHODS: Evaluation of an intervention program to reduce prophylactic antimicrobial doses. The intervention included weekly staff discussions, automatic dispensation of 1g-vial of cefazolin by the pharmacy unless expressly requested by surgeon and increase in post-discharge surveillance as a strategy to reassure surgeons of the safety of the reduction. In the pre and post intervention periods, a prospective study of antimicrobial consumption and surgical site infections were measured. RESULTS: There were 5,164 and 5,204 deliveries in 2001-2002 and 2003-2004, respectively; 1,524 (29.5%) and 1,363 (26%) were cesarean sections. There was a 45% decrease in cefazolin vials used on average per cesarean section (2.29 to 1.25). Patients evaluated increased from 16% to 67% and the SSI rates in both periods were 3.34% to 2.42%, respectively. CONCLUSION: An ample intervention, including administrative and educational measures, led to high compliance with dose reduction and saved more than US$4,000 in cefazolin, considered important because government reimbursement in Brazil for cesarean section is $80.
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Old timber structures may show significant variation in the cross section geometry along the same element, as a result of both construction methods and deterioration. As consequence, the definition of the geometric parameters in situ may be both time consuming and costly. This work presents the results of inspections carried out in different timber structures. Based on the obtained results, different simplified geometric models are proposed in order to efficiently model the geometry variations found. Probabilistic modelling techniques are also used to define safety parameters of existing timber structures, when subjected to dead and live loads, namely self-weight and wind actions. The parameters of the models have been defined as probabilistic variables, and safety of a selected case study was assessed using the Monte Carlo simulation technique. Assuming a target reliability index, a model was defined for both the residual cross section and the time dependent deterioration evolution. As a consequence, it was possible to compute probabilities of failure and reliability indices, as well as, time evolution deterioration curves for this structure. The results obtained provide a proposal for definition of the cross section geometric parameters of existing timber structures with different levels of decay, using a simplified probabilistic geometry model and considering a remaining capacity factor for the decayed areas. This model can be used for assessing the safety of the structure at present and for predicting future performance.
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A conjuntura económica da construção não se encontra numa fase de prosperidade, existindo a necessidade de criar soluções construtivas que permitam a redução de custos dos materiais a nível de obra. As lajes de betão armado, devido à sua grande área de implantação, possuem uma parcela importante no orçamento final de qualquer obra de edifícios correntes. Sabendo das possibilidades de aligeiramento de lajes, torna-se necessária a realização de um estudo pormenorizado e comparativo entre soluções de aligeiramento. O desenvolvimento deste relatório reflete todo o trabalho efetuado durante a realização de um estágio curricular desenvolvido na empresa FercaNorte – Estruturas, Lajes e Cofragens, Lda. e foca-se num dimensionamento e estudo comparativo de soluções de lajes fungiformes aligeiradas, aplicadas a dois casos de estudo e também num dimensionamento e estudo comparativo de soluções de lajes aligeiradas unidirecionais mas apenas aplicadas a um caso de estudo. No primeiro caso de estudo, laje fungiforme com um vão de 6 metros nas duas direções, são dimensionadas e comparadas quatro soluções: laje fungiforme maciça; laje fungiforme aligeirada com blocos elipsoides perdidos dispostos de forma ortogonal e envolvidos totalmente por betão; laje fungiforme aligeirada com blocos elipsoides perdidos dispostos em formato de favo de mel e envolvidos totalmente por betão; e laje fungiforme nervurada com moldes recuperáveis. No segundo caso de estudo, laje fungiforme com um vão de 7,04 metros nas duas direções, são dimensionadas e comparadas cinco soluções: laje fungiforme maciça, laje fungiforme aligeirada com blocos cúbicos perdidos dispostos de forma ortogonal e envolvidos totalmente por betão; laje fungiforme aligeirada, com blocos elipsoides perdidos dispostos de forma ortogonal e envolvidos totalmente por betão; laje fungiforme aligeirada com blocos elipsoides perdidos dispostos em formato de favo de mel e envolvidos totalmente por betão; e laje fungiforme nervurada com moldes recuperáveis. No terceiro caso de estudo, laje unidirecional com um vão de 8 metros apoiada em vigas com vão de 5 metros, são dimensionadas e comparadas três soluções: laje maciça; laje aligeirada com perfis tubulares com secção transversal reta oval; e laje nervurada com moldes recuperáveis. No final é apresentada uma estimativa orçamental para cada solução analisada nos três casos de estudo abordados.
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics