Regimento interno da Biblioteca Homero Abílio Moreira.

bitstream/item/82560/1/Regimento-interno.pd

Towards a multi-dimensional methodology supporting a safeguarding decision on the future access to mineral resources

A multi-dimensional methodology is proposed to delimit areas hosting mineral resources of public importance (MRoPI). The assessment procedure considers the Level of Geological Knowledge (LGK) along with the Economic (Ec), Environmental (Ev) and Social Development and Acceptance (SDA) dimensions. Different sets of independent, but complementary and variably weighed, criteria support the appraisal of each dimension, and a final score (MRoPI r ) results from a reasonable balance between LGK and (Ec + Ev + SDA). A ranking based on MRoPI r will fall in the [1, 10] interval, as imposed by the scaling normalising factor, but only specific tracts having MRoPI r  ≥ 4 display LGK values confident enough to be covered by a safeguarding decision at a given time. Adequate MRoPI r mapping can also be done, interpolating within the kriging formalism and evaluating thoroughly the modelling results until achieving the final map. The methodology application shows in addition that the combined use of LGK, Ec, Ev and SDA allows to address suitably two overlapping and coexisting, although different, issues: (1) safeguarding the future access to mineral resources and (2) planning the mineral development in the short-medium term, recognising the need of assigning specific areas to mining activities.info:eu-repo/semantics/publishedVersio

Temperature and pressure distribution analysis on deformable short hydrodynamic bearings

This paper presents a discussion on the study of thermal and elastic effects resulting from the support bearing. It was proposed a mathematical model based on the short bearings equations within the cavitation region, using the principle of mass continuity. Then, the used equations are deduced from [1] and energy equations applying a modified solution for the Ocvirk’s solution [2]. All the equations are numerically solved by the Backward Finite Difference Method. In addition of the treatment of fluid mechanics, this paper agrees the thermal analysis on bearings discussed by [3]. To calculate the deformation of the structure, it was used a Finite Element Model for a specific geometry and an evaluation of the variation of the pressure field is done to determinate how this difference affects other fluid properties. Finally, it was calculated within the full model to predict the short bearing properties. Comparing the similarities among the presented by [4] and the calculated ones, the mean results present a difference of 2.33% between the maximum pressure, and one about 1.78% for eccentricity ratio for a length-diameter bearing ratio (LDR) of ½. These results demonstrates that the model has an interesting relevant and accurate approximation for experimental data, reducing the time for calculate some initial properties or making qualitative decisions about its operation.The authors gratefully acknowledge the funding by Mechanical Engineering Department of the Polytechnic School, USP, Brazil, and the scholarship provided by CAPES

Optimizing the train-catenary electrical interface in AC railways through dynamic control reconfiguration

The power supply architecture of most AC electric railway vehicles is constituted by transformers and catenaries at increasingly high power levels. Inside the vehicles, the interface between the catenary and the DC-bus of the traction motors is based on a transformer and power electronics converters. A large part of these are AC-DC four quadrant converters that operate in parallel at relatively small switching frequencies. However, the use of the interleaving principle allows reaching a low harmonic distortion of the catenary current and imposing specific harmonic ranges in this current. Nevertheless, the current is not a pure sinusoidal wave and its harmonics can excite unwanted resonances due to the combined effect of the catenary distributed parameters, the substation equivalent impedance and the current frequency spectrum. This paper analyses this phenomenon and proposes a control strategy capable of minimizing the resonance effects in two different power supply architectures.The research has received funding from the FCT (Fundação para a Ciência e Tecnologia) under grant PD/BD/128051/2016. This work was partially supported by: FCT R&D Unit SYSTEC - POCI-01-0145-FEDER006933/SYSTEC funded by FEDER funds through COMPETE 2020 and by national funds through the FCT/MCTES, and co-funded by FEDER, in the scope of the PT2020 Partnership Agreement

Ventilação Não-Invasiva no Edema Agudo do Pulmão no Serviço de Urgência

Abstract Bilevel positive pressure (BiPAP) non-invasive ventilation (NIV) is frequently used in our emergency department (ED), as an adjuvant in the treatment of acute cardiogenic pulmonary edema (ACPE) to reduce the need for tracheal intubation (TI) in these patients. The purpose of our study was to evaluate the safety of NIV in patients with ACPE in our ED, used by a group of physicians outside the intensive care unit (ICU), by comparing our results with previously published results. We also wanted to identify possible additional advantages of NIV in the treatment of acpe. We recorded clinical and physiological data before and after NIV of all patients with diagnosis and treatment of ACPE in our ED and for whom NIV was ordered as adjuvant treatment, between July 2004 and February 28 2005. During this period, NIV was ordered in 17 patients with ACPE. The mean ventilation pressures used were p(INSP) 16.5 +/- 5 cm H2O and p(exp) 8.8 +/- 4 cm H2O. none of the patients refused NIV. In six patients NIV was not initiated immediately together with medical therapeutics. one patient required Ti and the other 16 (94%) improved after NIV. After the acpe episode had resolved, fourteen patients (82%) were eventually discharged from hospital whereas 3 (18%) died during hospitalization. We observed a statistically significant improvement after one hour of NIV in respiratory and pulse rate, arterial pH, PaCO2 and peripheral blood O2 saturation. Despite the small sample size, these results suggest that it is possible to use NIV in the treatment of ACPE outside the ICU, without increasing the risks of TI or decreasing efficacy. In these cases NIV probably accelerates clinical resolution and relieves symptoms

Reactivation of hepatitis B virus infection during treatment of hepatitis C with direct-acting antivirals

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The incidence of cancer and potential role of sirolimus immunosuppression conversion on mortality among a single-center renal transplantation cohort of 1,816 patients

INTRODUCTION: The chronic use of immunosuppressive drugs in renal transplant recipients increases the risk of developing de novo malignancies. Herein we analyze the incidence of de novo tumors and the potential role of sirolimus to improve cancer-specific survival among a cohort at a single center. METHODS: This retrospective analysis of our 1,816 patients allografted between January 1983 and December 2009 sought subjects who developed de novo tumors. Epidemiological and clinical data were examined using Mann-Whitney and Pearson's chi-square or Fisher exact tests for statistical comparisons of continuous and categorical variables, respectively. Kaplan-Meier survival curves were used to determine cancer-specific survival according to type of neoplasia and immunosuppressive regimen, namely, conversion to sirolimus. RESULTS: One hundred patients (5.5%) were diagnosed with a de novo malignancy. The 110 different cancers were diagnosed at a median interval of 73 months after kidney transplantation. The overall cancer-specific survivals at 1 and 5 years after cancer diagnosis were 87.0% and 76.9%, respectively. The 15 patients converted to sirolimus showed no difference in survival. CONCLUSION: The observed frequencies of cancer in our center are consistent with the literature. Among our cohort, sirolimus did not significantly impact survival among subjects who had de novo malignancies