ESTCB - Artigos em revistas com arbitragem científica
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- Adapting portuguese architecture to former african colonies climate conditionsPublication . Ferreira, Ana Vaz; Silva, J.A. Mendes daThe Portuguese architecture is borderless due to the colonialism period. Many African countries can testify this influence and the cities still sprawling around remaining old buildings. These constructions are characterized by using local resources and adapting Portuguese architecture to the climatic characteristics and answering local natural hazards. The work developed presents a systematic approach about the constructive changes, identifying the solutions adopted for answering climatic demands. The passive solar systems used were categorized and some examples were selected according to examples found in African cities with Portuguese influence as Beira (Mozambique), Lubango, Namibe and Luanda (Angola) and Praia (Cape Verde). This analysis encompasses strategies to improve thermal behavior of buildings, as ventilation trough the analysis of ventilated roofs or windows geometry, shadowing devices as large eaves, brises and second facades, among other issues. The local construction was also analyzed in order to find out traditional techniques for cooling buildings in a natural way.
- Algae in acid mine drainage and relationships with pollutants in a degraded mining ecosystemPublication . Gomes, Patrícia; Valente, Teresa; Albuquerque, M.T.D.; Henriques, Renato; Flor-Arnau, Núria; Pamplona, Jorge; Macías, FelipeAcid mine drainage represents an extreme environment with high concentrations of potentially toxic elements and low pH values. These aquatic habitats are characterised by harsh conditions for biota, being dominated by acidophilic organisms. The study site, São Domingos mine, located in one of the largest metallogenetic provinces in the world, the Iberian Pyrite Belt, was closed without preventive measures. To identify the algae species and understand the relationships with abiotic parameters of the ecosystem, water and biological material were collected and analysed. Digital terrain models were obtained with an unmanned aerial vehicle for geomorphological and hydrologic characterisation of the mine degraded landscape. The results show two types of algal colours that seem to represent different degrees of photosynthetic activity. Optical and scanning electron microscopy revealed 14 taxa at the genus level, divided into eight classes. The genus Mougeotia is the most abundant multicellular algae. With respect to unicellular algae, diatoms are ubiquitous and abundant. Abiotic analyses expose typical features of acid mine drainage and support an inverse relationship between chemical contamination and biological diversity. Factorial correspondence analysis indicates three groups of attributes and samples by their relationship with specific toxic elements. This analysis also suggests a close association between Spirogyra and Pb, together composing a structurally simple ecosystem. The highest contamination in the river system is related to the hydrologic patterns obtained from photogrammetric products, such as the digital surface model and flow map accumulation, indicating the input of leachates from the section having the finest sulfide-rich wastes. Information about the algae community and their association with flow patterns of toxic elements is a relevant tool from a biomonitoring perspective.
- Aligning software engineering teaching strategies and practices with industrial needsPublication . Metrôlho, J.C.M.M.; Ribeiro, Fernando Reinaldo; Graça, Paula; Mourato, Ana; Figueiredo, David; Vilarinho, HugoSeveral approaches have been proposed to reduce the gap between software engineering education and the needs and practices of the software industry. Many of them aim to promote a more active learning attitude in students and provide them with more realistic experiences, thus recreating industry software development environments and collaborative development and, in some cases, with the involvement of companies mainly acting as potential customers. Since many degree courses typically offer separate subjects to teach requirements engineering, analysis and design, coding, or validation, the integration of all these phases normally necessitates experience in a project context and is usually carried out in a final year project. The approach described in this article benefits from the close involvement of a software house company which goes beyond the common involvement of a potential customer. Students are integrated into distributed teams comprising students, teachers and IT professionals. Teams follow the agile Scrum methodology and use the OutSystems low-code development platform providing students with the experience of an almost real scenario. The results show that this approach complements the knowledge and practice acquired in course subjects, develops the students’ technical and non-technical skills, such as commitment, teamwork, and communication, and initiates them in the methodologies and development strategies used in these companies. The feedback from the teachers involved, software companies and students was very positive.
- An analytical approach to the ventilation effectiveness of mediterranean buildings: case study: existing residential building, PortugalPublication . Salehi, Atefeh; Torres, Isabel; Ferreira, Ana VazBuilding airtightness assumes an important role in the energy saving and the indoor thermal comfort. Ventilation rates bring significant impacts on energy usage in the constructions and indoor contaminant concentrations and also setting them as the key parameters in building performance. Ventilation rate have been measured in building for a long time, and there are some developed measurement methodologies related to it in the research domains. However, most of the investigations in recent years have been done usually in the cold climate conditions, while Mediterranean construction are not deeply investigated in the literature. In this paper, the authors present the obtained results of an experimental research which is carried out on the Portuguese residential buildings. The investigation is done by fan pressurization methods, also known as “Blower Door Test (BDT)” as the measurement method as well as Design Builder (DB) as the simulation software. The airtightness measurement of the existing buildings and the influence of air leakage on energy consumption and indoor comfort in different Portuguese construction typologies are focused on the aim of the research. The important parameters of the building such as whole-building air change rates, building infiltration rates, and ventilation effectiveness rate in the residential building are also considered in this research.
- An Eco-Energetic performance comparison of dehumidification systems in High-Moisture indoor environmentsPublication . Santos, Alexandre F.; Gaspar, Pedro Dinis; Souza, Heraldo J.L.; Caldeira, J.M.L.P.; Soares, V.N.G.J.This study discusses the choice of dehumidification systems for high-moisture indoor environments, such as indoor swimming pools, supported by an eco-energetic performance comparison. Initially, the causes of the high relative humidity and condensation in these spaces are reported, as well as the available dehumidification technologies. Two different solutions are described: desiccant wheel dehumidification and re-cooling. The energy demand required by a refrigeration system is lower than the desiccant wheel; however, the former system requires less maintenance and does not require refrigerant fluid. An eco-energetic comparison is performed between the two systems in two countries with different energy matrices (Brazil and USA). In Brazil, the desiccant wheel is the best choice for the past 10 years, with a predicted 351,520 kgCO2 of CO2 emissions, which is 38% lower than the refrigeration system. In the USA, the best option is the refrigeration system (1,463,350 kgCO2), a 12% more efficient option than desiccant wheels. This model can be considered for energy and CO2 emissions assessment, predicting which system has better energy efficiency and lower environmental impact, depending on the refrigerant type, location and environmental conditions.
- Analysis and improvement of the packaging sector of an industrial companyPublication . Alves, Diogo; Ferreira, Luís Pinto; Pereira, T.; Sá, J.C.; Silva, F.J.G.; Fernandes, Nuno O.Manual operations in manufacturing companies are still a common practice. This often results in high costs, high cycle times and therefore in lower productivity, particularly for companies operating in western countries. This is why many manufacturing companies relocated their production facilities in low age countries. This study was developed at a leading Portuguese material construction manufacturing company. The objective was to improve the packaging and labeling processes, that were identified as main bottlenecks in the factory. Lean was used to streamline these processes before being automated. This allowed for annual savings of 12432 €, with human operators being reallocated to other departments where they are more useful. Furthermore, cycle times were reduced by 42,9%, non-value-added activities were minimized, and operations with potentially high ergonomic risks were eliminated. In addition, a reduction of 84,3% in lithographed packaging was achieved, with a cost reduction of around 36 000 €/year, which is expected to continue in the forthcoming years.
- Aplicação para detetar e corrigir a postura em exercícios físicosPublication . Gonçalves, João; Palhares, João; Soares, V.N.G.J.; Neves, Paulo AlexandreNo ritmo acelerado da vida moderna a prática regular de exercício físico emerge como fonte de vitalidade e bem-estar. No entanto nem sempre é possível a deslocação ao ginásio e/ou pagar a um treinador pessoal. A opção por exercícios sem equipamentos usando o peso do corpo é apelativa pelos benefícios e baixo custo, mas podem surgir lesões pela sua má execução, nomeadamente devido a postura incorreta. Este trabalho apresenta uma abordagem para permitir, utilizando técnicas de visão computacional, detectar que exercício o praticante está a executar e analisar a postura, sem necessidade de intervenção de uma terceira pessoa. Os principais contributos deste artigo são: 1) Desenvolvimento de um dataset robusto para deteção de 3 exercícios de ginástica diferentes, 2) Avaliação do desempenho do modelo YOLOv8, bem como alguns dos seus diferentes níveis, usando o dataset desenvolvido; 3) Criação de um protótipo de aplicação para detetar um exercício e corrigir a realização do mesmo por parte dos utilizadores. O principal objetivo é fornecer aos utilizadores uma forma de facilitar a realização de atividade física, em qualquer lugar, sem a necessidade de acompanhamento especial ou equipamentos externos, sendo ao mesmo tempo um adjuvante para garantir que não ocorrem lesões por má postura.
- Application of wireless sensor networks to healthcare promotionPublication . Neves, Paulo Alexandre; Stachyra, Michal; Rodrigues, JoelBorn on military applications, wireless sensor networks (WSNs) application grew on the promise of environment sensing and data processing capability at low cost. These networks can hold hundreds or even thousands of smart sensing nodes with processing and sensing capabilities and even integrated power through a dedicated battery. This paper surveys on the application of wireless sensor networks to healthcare promotion, namely with the use of biosensor technology applied to body sensor networks. On a wireless body sensor network, a person wears biosensors to gather data, while doing their daily activities. Currently, engineers and medical staff are cooperating on finding new ways to properly gather meaningful data on-site and achieve a convenient way to process these data for research and on-site medical decision. New challenges that such approach brings are also considered. Moreover, it is shown that wireless sensor networks provide the technology to built wireless sensing and create a convenient infrastructure for multiple data gathering in healthcare applications. Together with real successful examples, we demonstrate the great usefulness of wireless sensor networks in healthcare promotion. The paper concludes with some guidelines for future work.
- Architecture of a fieldbus message scheduler coprocessor based on the planning paradigmPublication . Martins, Ernesto V.; Neves, Paulo Alexandre; Fonseca, José A.The use of a centralised planning scheduler in fieldbus-based systems requiring real-time operation has proved to be a good compromise between operational ̄exibility and timeliness guarantees. It is particularly well adapted to embedded systems based on low-processing power microcontrollers due to the low overhead it imposes. In this paper a preliminary implementation of a hardware scheduling coprocessor based on the planning paradigm is presented. The coprocessor is installed in a special node of the fieldbus, the bus arbiter, and generates scheduling tables to be dispatched by the node CPU. With this solution it is possible to decrease the response time to changes in the system con®guration or message parameters of the software- based planning scheduler. This opens the possibility of allowing automatic on-line changes requested by system nodes in addition to the ones requested by human operators, thus improving system reactivity. The paper includes a short review of the planning technique and a discussion on the motivation to develop the coprocessor as well as on recent similar and related work. The coprocessor architecture and several implementation details such as its interface with the arbiter CPU are presented. The initial calculations showing the feasibility of the unit are also derived, together with the first real implementation of the coprocessor itself.
- Artificial intelligence decision support system based on artificial neural networks to predict the commercialization time by the evolution of peach qualityPublication . Ananias, Estevão; Gaspar, Pedro Dinis; Soares, V. N.G.J; Caldeira, J.M.L.P.Climacteric fruit such as peaches are stored in cold chambers after harvest and usually are maintained there until the desired ripening is reached to direct these fruit to market. Producers, food industries and or traders have difficulties in defining the period when fruit are at the highest level of quality desired by consumers in terms of the physical-chemical parameters (hardness –H–, soluble solids content –SSC–, and acidity –Ac–). The evolution of peach quality in terms of these parameters depends directly on storage temperature –T– and relative humidity –RH–, as well on the storage duration –t–. This paper describes an Artificial Intelligence (AI) Decision Support System (DSS) designed to predict the evolution of the quality of peaches, namely the storage time required before commercialization as well as the late commercialization time. The peaches quality is stated in terms of the values of SSC, H and Ac that consumers most like for the storage T and RH. An Artificial neuronal network (ANN) is proposed to provide this prediction. The training and validation of the ANN were conducted with experimental data acquired in three different farmers’ cold storage facilities. A user interface was developed to provide an expedited and simple prediction of the marketable time of peaches, considering the storage temperature, relative humidity, and initial physical and chemical parameters. This AI DSS may help the vegetable sector (logistics and retailers), especially smaller neighborhood grocery stores, define the marketable period of fruit. It will contribute with advantages and benefits for all parties—producers, traders, retailers, and consumers—by being able to provide fruit at the highest quality and reducing waste in the process. In this sense, the ANN DSS proposed in this study contributes to new AI-based solutions for smart cities.