Ciências e Tecnologia / Sciences and Technology
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Browsing Ciências e Tecnologia / Sciences and Technology by Sustainable Development Goals (SDG) "09:Indústria, Inovação e Infraestruturas"
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- Automated design of priority rules for resource-constrained project scheduling problem using surrogate-assisted genetic programmingPublication . Luo, Jingyu; Vanhoucke, Mario; Coelho, JoséIn the past few years, the genetic programming approach (GP) has been successfully used by researchers to design priority rules for the resource-constrained project scheduling problem (RCPSP) thanks to its high generalization ability and superior performance. However, one of the main drawbacks of the GP is that the fitness evaluation in the training process often requires a very high computational effort. In order to reduce the runtime of the training process, this research proposed four different surrogate models for the RCPSP. The experiment results have verified the effectiveness and the performance of the proposed surrogate models. It is shown that they achieve similar performance as the original model with the same number of evaluations and better performance with the same runtime. We have also tested the performance of one of our surrogate models with seven different population sizes to show that the selected surrogate model achieves similar performance for each population size as the original model, even when the searching space is sufficiently explored. Furthermore, we have investigated the accuracy of our proposed surrogate models and the size of the rules they designed. The result reveals that all the proposed surrogate models have high accuracy, and sometimes the rules found by them have a smaller size compared with the original model.
- Behaviour of low molecular weight compounds, iron and copper of wine spirit aged with chestnut staves under different levels of micro-oxygenationPublication . Canas, Sara; Danalache, Florina; Anjos, Ofélia; Fernandes, Tiago; Caldeira, Ilda; Santos, Nádia; Fargeton, Laurent; Boissier, Benjamin; Catarino, SofiaAlternative technologies for a more sustainable wine spirits’ ageing have been studied but a lack of knowledge on the effect of oxygenation level remains. This work examined the behaviour of low molecular weight compounds, iron and copper of a wine spirit aged in 50 L demijohns with chestnut wood staves combined with three levels of micro-oxygenation or nitrogen. Compounds and mineral elements were quantified by HPLC and FAAS, respectively, in samples collected at 8, 21, 60, 180, 270 and 365 days of ageing. Results showed that most of the compounds underwent significant changes in their content over time and behave differently depending on the wine spirit’s oxygenation level: higher contents of gallic acid, syringic acid and vanillin were associated with lower micro-oxygenation level while higher contents of ellagic acid, syringaldehyde, coniferaldehyde and sinapaldehyde resulted from higher one; lowest contents of these compounds were found in the nitrogen modality. Weak correlation between copper and the studied compounds was evidenced whereas closer relationship between iron, vanillin, gallic, syringic and ellagic acids at end of ageing was observed. This study provides innovative information on the role of oxygen in wine spirit’s ageing, and on chestnut wood effect on wine spirit’s mineral composition.
- Capillary viscometry for routine measurements of newtonian liquidsPublication . Sequeira, Maria Carolina; Caetano, Fernando J. P.; Fareleira, João M. N. A.Viscosity is a thermophysical property of paramount importance, being essential for many scientific and industrial applications. The most common instruments for its measurement are glass capillary viscometers. Therefore, the use of capillary viscometers is widespread both in industry and in research. The range of viscosities of interest range from lower than that of water to several orders of magnitude higher values, the measurement of which requires different capillary viscometers. Most of the practical applications concern routine instruments, mainly for quality control. One main issue for the utilization of capillary viscometers relates to the need for their calibration, assuring its traceability to the water primary viscosity standard, to certify its worldwide validity. The present paper focuses on capillary instruments dedicated to perform viscosity measurements on Newtonian organic liquids at atmospheric pressure, as it is assumed that is the most widespread type of application for these viscometers. Capillary viscometry has a completely well-defined working equation, namely, the Hagen–Poiseuille equation. However, the practical performance of the measuring instruments deviates from that working equation. Most of those deviations are currently considered by many users. However, some of those deviations have not reached that status yet, like those concerning the effects due to the surface tension of the sample on the measurements. All these aspects are summarized and analyzed in the present article, together with a brief general description of the most common types of capillary viscometers, namely, the Ostwald and the constant-level or Ubbelohde instruments.
- Challenges ahead for sustainable cities: an urban form and transport system reviewPublication . Medina Monteiro, João Pedro; Sousa, Nuno; Coutinho-Rodrigues, João; Natividade-Jesus, EduardoThis article reviews the critical issues surrounding the development of sustainable urban environments, focusing on the impact of transport and urban form on energy consumption and greenhouse gas emissions. The aim is to provide an overview of the state-of-the-art on the subject and to unravel what directions the literature suggests for sustainable urban planning. Current research and practices are synthesized, highlighting the interdependence of urban design and transportation systems in achieving sustainability goals. Important dimensions and practices of city planning and transport policies are explored, including urban form, urban sprawl, mixed land use, densification and infill, and urban public spaces, and how these directly influence transport dynamics, including modal choices and energy consumption. Innovative approaches in urban planning, such as transit-oriented development, and technological advancements, such as electric mobility, are also examined and their potential roles in sustainable urban transport. The conclusion underscores the urgency of adopting holistic and adaptable strategies to foster sustainable urban environments, calling for concerted efforts from policymakers, urban planners, and communities. Awareness of the conclusions can help municipal decision-makers in planning their cities for a sustainable future. Finally, the authors analyze important directions for future research and practical applications towards developing cities that are environmentally sound, socially equitable, and economically viable.
- Correction: Di-Alkyl Adipates as new phase change material for low temperature energy storagePublication . Nogueira, Bernardo A.; Diogo, Hermínio P.; Fausto, Rui; Caetano, Fernando J. P.; Fareleira, João; Sequeira, Maria CarolinaThe following is a correction to the supplementary information of the paper titled “Di-Alkyl Adipates as new phase change material for low temperature energy storage” by Maria C.M. Sequeira, Bernardo A. Nogueira, Fernando J.P. Caetano, Hermínio P. Diogo, João M.N.A. Fareleira, Rui Fausto that appeared in International Journal of Thermophysics 44:165 (2023). https://doi.org/10.1007/s10765-023-03274-3
- Di-Alkyl adipates as new phase change material for low temperature energy storagePublication . Sequeira, Maria Carolina; Nogueira, Bernardo A.; Caetano, Fernando J. P.; Diogo, Herminio; Fareleira, João M. N. A.; Fausto, RuiThis work is a contribution to the thermal characterization of a selected binary system of two di-n-alkyl adipates that can be used as phase change material for thermal energy storage at low temperatures. The construction of the solid–liquid phase diagram using differential scanning calorimetry (DSC), complemented with Raman Spectroscopy studies for the system composed by diethyl and dibutyl adipates is presented. The solidus and liquidus equilibrium temperatures were determined by DSC for the pure components and 30 binary mixtures at selected molar compositions were used to construct the corresponding solid–liquid phase diagram. The binary system of diethyl and dibutyl adipates presents eutectic behaviour at low temperatures. The eutectic temperature was found at 240.46 K, and the eutectic composition was determined to occur at the molar fraction xdibutyl = 0.46. Additionally, the system shows a polymorphic transition, characteristic of dibutyl adipate, occurring at ca. 238 K, confirmed by optical microscopy. To the best of our knowledge, no reference to the phase diagram of the present system could be found in the literature. Raman spectroscopy was essential to complement the construction of the phase equilibrium diagram, enabling the identification of the solid and liquid phases of the system. Finally, the liquidus curve of the phase diagram was also successfully predicted using a suitable fitting equation, being the root mean square deviation of the data from the correlation equal to 0.54 K. In addition, this fitting operation enabled a correct prediction of the eutectic composition of the system.
- Face-to-face interactions estimated using mobile phone data to support contact tracing operationsPublication . Cumbane, Silvino; Gidófalvi, Gyözö; Cossa, Osvaldo; Madivadua Júnior, Afonso; Branco, Frederico; Sousa, NunoUnderstanding people’s face-to-face interactions is crucial for effective infectious disease management. Traditional contact tracing, often relying on interviews or smartphone applications, faces limitations such as incomplete recall, low adoption rates, and privacy concerns. This study proposes utilizing anonymized Call Detail Records (CDRs) as a substitute for in-person meetings. We assume that when two individuals engage in a phone call connected to the same cell tower, they are likely to meet shortly thereafter. Testing this assumption, we evaluated two hypotheses. The first hypothesis—that such co-located interactions occur in a workplace setting—achieved 83% agreement, which is considered a strong indication of reliability. The second hypothesis—that calls made during these co-location events are shorter than usual—achieved 86% agreement, suggesting an almost perfect reliability level. These results demonstrate that CDR-based co-location events can serve as a reliable substitute for in-person interactions and thus hold significant potential for enhancing contact tracing and supporting public health efforts.
- Física : cinemática : MRU + MRUVPublication . Sousa, Nuno; Silva, Fátima Ferreira da; Silva, Helder Matta e
- Física : dinâmicaPublication . Sousa, Nuno; Silva, Fátima Ferreira da; Firmino, Joaquim
- Física : dinâmica : 2º exemploPublication . Sousa, Nuno; Silva, Fátima Ferreira da; Firmino, Joaquim