ESTG - Comunicações em conferências e congressos internacionais
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Browsing ESTG - Comunicações em conferências e congressos internacionais by Field of Science and Technology (FOS) "Ciências Naturais::Ciências da Terra e do Ambiente"
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- Assessing the influence of uncertainty in land cover mapping and digital elevation models on flood risk mappingPublication . Gonçalves, Luísa M.S.; Fonte, Cidália C.; Gomes, RicardoThis paper proposes an approach to assess the influence of the uncertainty present in the parameters dependent on the land cover and elevation data over the peak flow values and the subsequent delineation of flooded areas. The proposed approach was applied to produce vulnerability and risk maps that integrate uncertainty for the urban area of Leiria, Portugal. A SPOT-4 satellite image and DEMs of the region were used. The peak flow was computed using the Soil Conservation Service method and HECHMS, HEC-RAS, Matlab and ArcGIS software programs were used. The analysis of the results obtained for the presented case study enables the identification of the order of magnitude of uncertainty associated to the watershed peak flow value and the identification of the areas which are more susceptible to flood risk to be identified.
- Energy management in municipal solid waste treatment: A case study of a mechanical biological treatment facilityPublication . Bernardo, Hermano; Oliveira, Filipe Tadeu; Quintal, EdgarOver the last few years, mechanical biological treatment systems for municipal solid waste have been introduced in many European countries. In most cases, this was driven by the European Union Landfill Directive, which requires the diversion of biodegradable municipal waste from landfill to alternative processes. Although this type of treatment allows energy recovery from municipal solid waste, the process of mechanical biological treatment appears to be an intensive energy consumer, due to high demand of electricity consumed by process equipment. This paper presents the main results of an energy audit performed to a Mechanical Biological Treatment facility in Portugal, which due to the amount of energy consumed must comply with the Portuguese Program called Intensive Energy Consumption Management System – SGCIE. The program was created in 2008 to promote energy efficiency and energy consumption monitoring in intensive energy facilities (energy consumption higher than 500 toe per year). Facilities operators are required to perform energy audits and take actions to draw up an action plan for energy efficiency, establishing targets for energy consumption reduction and greenhouse gases emissions indexes. To implement actions that improve energy efficiency, it is necessary for the facilities operation to be associated with an effective energy management methodology, as well as an efficient facilities management procedure. The implementation of any energy management system should start with an energy audit, which was carried out to identify potential energy conservation measures for improving energy efficiency, and also typical energy consumption patterns and sector/equipment load profiles. This tool gives managers the information to support decision making on improving energy performance and reducing greenhouse gas emissions. Results shown that there is a considerable potential for reducing energy consumption and greenhouse gases emissions on Mechanical Biological Treatment units. Here, as elsewhere in the industrial sector, energy efficiency can only be achieved through a continuous energy monitoring and management system.
- Indoor air quality audit in two office buildings in PortugalPublication . Ramos, Joao; Pinto, FernandoThe indoor air quality that a building presents is not always from our knowledge. In fact, we may find ourselves exposed to an indoor air which can be harmful to human health, affecting the quality of life and productivity, which also will have economic repercussions at this level. Given the Portuguese law for energy and indoor air quality (IAQ) certification of large service buildings, the indoor air quality requirements were here presented and, in addition, this paper provides an overview of the current Portuguese IAQ technical procedures to audit existent buildings. It was also intended with this study to evaluate the indoor air quality experienced by the occupants of two office buildings, an old and a recent, with the same activity and occupancy, without air-conditioning systems, where were carried out indoor air quality characterizations and, in particular, have been assessed the CO2 concentration and the typical renewal air exchange rates in different zones of the buildings, as a ventilation effectiveness monitoring. During the building's regular occupancy period, the authors have been done monitoring campaigns, which took place in winter and summer seasons. They have been detected that the values of some parameters under review were non-compliance situations in winter, in contrast with the summer due to the increase of ventilation promoted by the occupants taking advantage of the favourable conditions of the Mediterranean weather. Consequently, the proposed IAQ audit approach may be helpful to characterize indoor air pollutants, to evaluate the ventilation effectiveness and to correlate it with the indoor air quality perception and self-control actions of the occupants.
- Recommended improvements to current shear-friction provisions of model codePublication . Santos, Pedro M. D.; Júlio, Eduardo N. B. S.The shear-friction theory, first proposed by Birkeland and Birkeland (1966), was adopted by CEB-FIP Model Code 1990 to predict the longitudinal shear strength between parts of concrete members cast at different times. This is a relevant subject for different situations, such as the connection between precast members with cast-in-place parts and strengthening of existing RC members with a new concrete layer. Other situations, such as corbels; metallic supports subjected mainly to shear forces; regions near supports; and the connection between columns and foundations can also be designed using the shear-friction theory. It is known that surface roughness plays a significant role on the bond strength of concrete-to-concrete interfaces. Recent studies, using a laserbased device specifically developed to quantify the texture of concrete surfaces, proved that roughness can be measured and, moreover, correlated with the cohesion and friction coefficients present in the Model Code's design expression. Therefore, the current qualitative assessment of the surface roughness, merely based on a visual inspection, can be replaced by an accurate and quantitative approach. The curing conditions of the substrate concrete (old concrete) and of the added concrete layer (new concrete) are not considered either. This can have a significant influence because additional stresses can appear at the interface between both concrete layers due to differential shrinkage. Differential stiffness due to the difference between Young modulus is not addressed either. In this paper, improvements to Model Code 90's design expression for longitudinal shear strength between concretes cast at different times are recommended. Furthermore, a comparison between the design expressions proposed by the CEB-FIP Model Code 1990, the Eurocode 2 and the ACI 318 is presented.
- Sustainable tourism and the circular economy: A theoretical overviewPublication . Costa, Berta; Rodrigues, Susana; Moreno, PilarThe concept of sustainable tourism has become one of the most noteworthy topics among academics and practitioners and a hallmark in tourism discourse. During the last decades, tourism has developed into one of the largest socio-economic activities, and thus driving economic growth that most supports to the countries’ GDP (Gross Domestic Product). The world economic paradigm, and consequently the tourism industry, is configured according to the linear model of production and consumption, in which goods are discarded after usage, resulting in massive waste. Furthermore, the degrading impact of tourism, along with the assumption that natural resources are abounding, and that environment has unlimited means to absorb waste, need to be addressed without delay. Considering these premises, the principle of sustainable tourism arose with the objective of minimizing the negative effects of tourism related activities. From this standpoint, circular economy emerges as a solution, as it harmonizes economic development with the sustainable use of natural resources, and also enables the tourism industry to become more sustainable. The purpose of this article is to outline the conceptual dimensions of sustainable tourism and circular economy, and also scrutinize how these two constructs have evolved over the past decades and their correlation. A broad literature review was conducted, in order to draw attention to the constituent elements brought to discussion.