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Leiria, Portugal

The Polytechnic Institute of Leiria is a public institution of Higher Education that offers courses of training on an Undergraduate Degree, Masters, Post-Graduate, Technology Specialization and Preparation Courses for Access to Higher Education level. It began its activity in 1980 and is present in the Leiria and West region through its five schools, divided in five campus, located in the cities of Leiria , Caldas da Rainha and Peniche . IPL offers Undergraduate e Master Degrees courses in the areas of: Art and Design, Law studies, Education and Communication, Engineering and Technology, Tourism and Health. Wikipedia.

Domingues A.,University of Lisbon | Santos H.,Polytechnic Institute of Leiria | Costa M.,University of Lisbon
Energy | Year: 2013

This study evaluates the vehicle exhaust WHR (waste heat recovery) potential using a RC (Rankine cycle ). To this end, both a RC thermodynamic model and a heat exchanger model have been developed. Both models use as input, experimental data obtained from a vehicle tested on a chassis dynamometer. The thermodynamic analysis was performed for water, R123 and R245fa and revealed the advantage of using water as the working fluid in applications of thermal recovery from exhaust gases of vehicles equipped with a spark-ignition engine. Moreover, the heat exchanger effectiveness for the organic working fluids R123 and R245fa is higher than that for the water and, consequently, they can also be considered appropriate for use in vehicle WHR applications through RCs when the exhaust gas temperatures are relatively low. For an ideal heat exchanger, the simulations revealed increases in the internal combustion engine thermal and vehicle mechanical efficiencies of 1.4%-3.52% and 10.16%-15.95%, respectively, while for a shell and tube heat exchanger, the simulations showed an increase of 0.85%-1.2% in the thermal efficiency and an increase of 2.64%-6.96% in the mechanical efficiency for an evaporating pressure of 2 MPa. The results confirm the advantages of using the thermal energy contained in the vehicle exhaust gases through RCs. Furthermore, the present analysis demonstrates that improved evaporator designs and appropriate expander devices allowing for higher evaporating pressures are required to obtain the maximum WHR potential from vehicle RC systems. © 2012 Elsevier Ltd.

Santos P.M.D.,Polytechnic Institute of Leiria | Julio E.N.B.S.,University of Lisbon
Engineering Structures | Year: 2012

Initially proposed in 1966, the " shear-friction theory" has been adopted in all design codes to analyse concrete-to-concrete interfaces. In the last decades, several improvements were suggested to take into account more influencing factors, to increase the accuracy and to enlarge the application field. The inclusion of the concrete strength and density and the consideration of the dowel action are examples of the proposed improvements.This paper presents a literature review on design expressions for shear-friction, chronologically ordered, describing proposals from the earliest research studies, precursors of the theory, until the most recent studies, incorporated in the newest fib Model Code. The most significant contributions are identified and a comparison between some of these design expressions is presented. Codes updates concerning shear-friction provisions are also identified in the literature review herein presented. © 2012 Elsevier Ltd.

Santos P.M.D.,Polytechnic Institute of Leiria | Julio E.N.B.S.,University of Lisbon
ACI Materials Journal | Year: 2011

The bond strength of concrete-to-concrete interfaces, of reinforced concrete (RC) members with parts cast at different ages, is highly influenced by the curing conditions. Therefore, the monolithic behavior is dependent on these conditions. Current design codes only consider: a) the concrete compressive strength; b) the normal stress at the interface; c) the amount of reinforcement crossing the interface; and d) the roughness of the substrate surface. Because the curing conditions of both substrate and added concrete are ignored, the influence of the differential shrinkage is neglected. The influence of the differential stiffness due to the mismatch between the Young's modulus of both materials is not considered either. This paper presents an experimental study conducted to assess the influence of differential shrinkage and stiffness on the bond strength of new-to-old concrete interfaces. Both parameters were shown to have a significant influence on the bond strength and failure mode of concrete-to-concrete interfaces. Copyright © 2011, American Concrete Intitute. All rights reserved.

Vasconcelos J.,Polytechnic Institute of Leiria
Environmental pollution (Barking, Essex : 1987) | Year: 2013

Mortality due to cardiovascular diseases shows a seasonal trend that can be associated with cold weather. Portugal is the European country with the highest excess winter mortality, but nevertheless, the relationship between cold weather and health is yet to be assessed. The main aim of this study is to identify the contribution of cold weather to cardiovascular diseases within Portugal. Poisson regression analysis based on generalized additive models was applied to estimate the influence of a human-biometeorological index (PET) on daily hospitalizations for myocardial infarction. The main results revealed a negative effect of cold weather on acute myocardial infarctions in Portugal. For every degree fall in PET during winter, there was an increase of up to 2.2% (95% CI = 0.9%; 3.3%) in daily hospital admissions. This paper shows the need for public policies that will help minimize or, indeed, prevent exposure to cold. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ganhao R.,Polytechnic Institute of Leiria | Morcuende D.,University of Extremadura | Estevez M.,University of Extremadura
Meat Science | Year: 2010

The influence of protein oxidation, as measured by the dinitrophenylhydrazine (DNPH) method, on colour and texture changes during chill storage (2. °C, 12. days) of cooked burger patties was studied. Extracts from arbutus-berries (Arbutus unedo L., AU), common hawthorns (Crataegus monogyna L., CM), dog roses (Rosa canina L., RC) and elm-leaf blackberries (Rubus ulmifolius Schott., RU) were prepared, added to burger patties (3% of total weight) and evaluated as inhibitors of protein oxidation and colour and texture changes. Negative (no added extract, C) and positive control (added quercetin; 230. mg/kg, Q) groups were also considered. The significant increase of protein carbonyls during chill storage of control burger patties reflect the intense oxidative degradation of the muscle proteins. Concomitantly, an intense loss of redness and increase of hardness was found to take place in burger patties throughout refrigerated storage. Most fruit extracts as well as Q significantly reduced the formation of protein carbonyls and inhibited colour and texture deterioration during chill storage. Likely mechanisms through which protein oxidation could play a major role on colour and texture changes during chill storage of burger patties are discussed. Amongst the extracts, RC was most suitable for use as a functional ingredient in processed meats since it enhanced oxidative stability, colour and texture properties of burger patties with no apparent drawbacks. © 2010 Elsevier Ltd.

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