Ciências e Tecnologia | Comunicações em congressos, conferências, seminários/Communications in congresses, conferences, seminars
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- Potential for trophic transfer of microplastics in the smallspotted catshark’s food web: insights from Portuguese coastal ecosystemsPublication . Pica, Rodrigo; Fernandes, João; Seixas, Sónia; Martins, Marta; Greife, Anna; Müller, Carolin; Heel, LenaMicroplastics (MPs) are increasingly prevalent pollutants in marine environments, raising concerns about their potential to transfer across trophic levels. However, the extent and significance of such transfer remain uncertain. This study aimed to (i) characterise MPs in the digestive tracts (GITs) of three ecologically connected species — the small-spotted catshark (Scyliorhinus canicula), pouting (Trisopterus luscus), and Henslow’s swimming crab (Polybius henslowii); and (ii) assess the potential for trophic transfer, as S. canicula is a known predator of the other two species. Thirty individuals from each species were collected by bottom-trawling off Figueira da Foz, Portugal. GITs were digested using 10% potassium hydroxide (KOH), filtered, and analysed by Fourier-transform infrared (FTIR) spectroscopy. A total of 88 MPs were identified, primarily in S. canicula (0.89 ± 1.19 MP.ind-1) and P. henslowii (0.54 ± 0.74 MP.ind-1). No MPs were found in T. luscus, possibly due to its juvenile stage or short retention time. Frequencies of occurrence were 57% for S. canicula and 43% for P. henslowii, representing the first record of MPs in the latter. The predominant MP types were fragments (51%) and fibres (47%), mainly green (32%), black (20%), and transparent (16%), with polyvinyl acetate (32%) and polyethene terephthalate (27%) identified as the main polymers. Significant differences in MP colour and polymer composition between species suggest distinct exposure routes. Although the presence of MPs in a known prey species of S. canicula suggests potential trophic transfer, further research is needed to confirm bioaccumulation. These findings provide a valuable baseline for understanding plastic pollution in coastal ecosystems and highlight the need for ongoing investigation into MP dynamics within marine food webs.
- Large language model for querying databases in PortuguesePublication . Figueiredo, Lourenço; Pinheiro, Paulo; Cavique, Luís; Marques, NunoThis study introduces a system that helps non-expert users find information easily without knowing database languages or asking technicians for help. A specific domain is explored, focusing on a subscription-based sports facility, which serves as an open-source version of a real case study. Utilizing the star schema, the available data in the database is structured to provide accessibility through Portuguese Natural Language queries. Using a Large Language Model (LLM), SQL queries are generated based on the question and the provided star schema. We created a dataset with 115 highly challenging questions drawn from real-world usage scenarios to validate the correctness of the system. Challenges found during testing, like attribute value interpretation, out-of-scope questions, and temporal interval adequacy issues, highlight the insufficiency of the star schema alone in providing the needed context for generating accurate SQL queries by the LLM. Addressing these challenges through enhanced contextual information shows significant improvement in query correctness, with validation results increasing from 57.76% to 88.79%. This study shows the potential and limitations of LLMs in generating SQL queries from Portuguese Natural Language queries.
- Data science maturity model: from raw data to pearl’s causality hierarchyPublication . Cavique, Luís; Pinheiro, Paulo; Mendes, Armando B.Data maturity models are an important and current topic since they allow organizations to plan their medium and long-term goals. However, most maturity models do not follow what is done in digital technologies regarding experimentation. Data Science appears in the literature related to Business Intelligence (BI) and Business Analytics (BA). This work presents a new data science maturity model that combines previous ones with the emerging Business Experimentation (BE) and causality concepts. In this work, each level is identified with a specific function. For each level, the techniques are introduced and associated with meaningful wh-questions.We demonstrate the maturity model by presenting two case studies.
- Inhomogenous amrketing mix diffusionPublication . Pinto, Luís G.; Cavique, Luís; Gomes, Orlando; Santos, Jorge M. A.In this article we extend the Marketing Mix Diffusion (MMD) model to inhomogenous networks (i.e. complex networks of arbitrary topology). The (Homogenous) MMD model is an innovation diffusion model, similar to the Bass model, which includes four decision variables (the 4Ps of Marketing: Product, Price, Place, Promotion). We introduce the Inhomogenous MMD (IMMD) model and we conduct two separate experiments: one based on simulation and another one relying on empirical evidence. The simulation study compares the behavior of the IMMD model with the classic Bass diffusion model. Results suggest that the classic Bass model is able to represent the IMMD curves quite well in most cases. The IMMD is more general and capable of representing extreme scenarios. The empirical study focuses on the geographic diffusion of mobile broadband technology in Japan, combining adoption data with a spatial network of municipalities. The in-sample performance of the model is comparable to the existing methods, which suggests a good explanatory power of the IMMD model.
- Considering traditional practices a study on the fishing and production of dried Sparisoma cretense in the Azores IslandsPublication . Brás, Márcia; Fraga, Ana; Seixas, SóniaThe practice of producing dried Sparisoma cretense (parrotfish), known locally as Veja seca, serves as a significant aspect of the maritime tradition in the Azores Islands. This study presents an interdisciplinary comprehensive analysis of the fishing and production techniques involved in Veja seca across the archipelago, while also characterizing the individuals engaged in this practice. Through structured surveys conducted on all nine islands (one hundred), this research meticulously documents the geographical distribution of Veja seca production and identifies the diverse fishing methods utilized, including shore fishing, boat fishing, and spearfishing, along with the optimal conditions for catch (bait, season, tide). Furthermore, it provides a detailed examination of the salting and drying processes, highlighting traditional methods of preservation and storage. By uncovering the sociocultural significance of Veja seca within Azorean communities this study elucidates its role in preserving local customs and sustaining cultural identity within coastal communities, which we believe to be an important contribute to be considered in local management process and fisheries management advice.
- Enhancing recruitment with LLMs and chatbotsPublication . Novais, Liliana; Rocio, Vitor; Morais, A. JorgeTraditional approaches in the competitive recruitment landscape frequently encounter difficulties in effectively identifying exceptional applicants, resulting in delays, increased expenses, and biases. This study proposes the utilisation of contemporary technologies such as Large Language Models (LLMs) and chatbots to automate the process of resume screening, thereby diminishing prejudices and enhancing communication between recruiters and candidates. Algorithms based on LLM can greatly transform the process of screening by improving both its speed and accuracy. By integrating chatbots, it becomes possible to have personalised interactions with candidates and streamline the process of scheduling interviews. This strategy accelerates the hiring process while maintaining principles of justice and ethics. Its objective is to improve algorithms and procedures to meet changing requirements and enhance the competitive advantage of talent acquisition within organisations.
- Formação Flash sobre IA Generativa: algumas notas para o desenvolvimento profissional docentePublication . Rocio, Vitor; Cruz, Elisabete; Freitas, João Correia de; Pereira, Carolina
- Low temperature thermal energy storage: insights into odd-even n-alkane systemPublication . Sequeira, Maria Carolina; Nogueira, Bernardo; Nikitin, Timur; Caetano, Fernando J. P.; Diogo, Herminio; Fausto, Rui; Fareleira, João M. N. A.
- Revisiting odd-even effects in n-alkane systemsPublication . Fausto, Rui; Sequeira, Maria Carolina; Caetano, Fernando J. P.; Diogo, Herminio; Fareleira, João M. N. A.; Nikitin, Timur; Fausto, Ruin-Alkanes have been widely studied for different applications. Recently, they became still more popular due to their exceptional characteristics as phase change materials (PCMs) for thermal energy storage (TES) applications [1]. In our research group, during the last three years, we have been studying the phase equilibrium behaviour of some binary systems with potential application as PCMs, including n-alkanes [2,3]. In this study, the n-alkanes family has shown some intriguing effects, related to the odd or even number of carbon atoms of the molecules on the characteristics of their solid-liquid phase equilibria. Several studies regarding the solid phase properties have been carried out to understand this type of phenomena in n-alkanes and compounds whose molecules contain alkyl groups. It has been established that n-alkanes exhibit different crystal packing arrangements according to their odd or even number of carbon atoms in their chains [4]. As a result, several properties are seen to be affected by the number of carbon atoms, revealing remarkable odd-even effects, which can eventually be used as an advantage for some specific applications [5]. This is particularly important to interpret and predict the solid-liquid phase equilibrium types of the diagrams, which is a key issue to select PCMs for TES applications. Most of the studies involving the properties of n-alkanes are devoted to the liquid phase. Therefore, along the years, a wide range of properties have been measured, predicted, correlated, and interpreted, including viscosity, density, heat capacity, vapour pressure, flash point, boiling point, and thermal conductivity. It is generally known that linear alkanes are an interesting homologous series, because they show a considerable regularity in their fluid phase properties, which allows to establish, for example, simple correlations based on the number of carbon atoms in the molecular chain [4]. Because of the raising importance of energy storage, namely TES, and the application of alkanes as PCMs, interest in their solid-liquid phase equilibria has increased. Consequently, it is interesting to picture an overall image on the thermophysical properties of n-alkanes, and, in particular to study the predictability of the main characteristics of their solid-liquid phase equilibria. Thus, this work aims to be a comprehensive view on the thermophysical properties and phase equilibrium behaviour of n-alkanes and their relation to the odd or even carbon atoms present in the alkyl chain.
- Seeking new low temperature energy storage systems: n-alkanes as phase change materialsPublication . Sequeira, Maria Carolina; Nogueira, Bernardo A.; Nikitin, Timur; Caetano, Fernando J. P.; Fareleira, João M. N. A.; Fausto , Rui; Diogo, HerminioOver the last decades, the increasing need for energy has been a tremendous challenge. Until now, fossil fuels have been the dominant energy source, however, due to their environmental consequences, renewable energies are the promising solution for the future.1 Nevertheless, the intermittent nature of most renewable energy sources often leads to a discrepancy between the energy produced and its consumption, which highlights the crucial role of energy storage technologies in enhancing clean energy utilization.2 From all energy storage solutions, thermal energy storage (TES) is one of the most promising options, showing substantial energy storage capacity at an acceptable cost.3 For these applications, phase change materials (PCMs) are particularly important, especially for low temperature energy storage systems. Linear alkanes (n-alkanes) have been studied as good candidates for TES applications mainly due to their singular phase transition performance, among others.4 In the present work, it has also been studied the differences due to the odd-even carbon chain number on the solid-liquid equilibrium properties that these materials can present, which is a key aspect crucial to characterize the systems for an upcoming use as PCMs. 4,5 to be used as new PCMs For TES applications, solid-liquid phase equilibrium is determinant to characterize the phase transitions which are more important for the application of these systems, as new PCMs. As an example, in the logistics associated to the transport of perishable consumables, like vaccines and other pharmaceutical products, TES plays an important role. In the present context, this work aims at the characterization of some selected n-alkane binary systems that can be used for energy storage applications at low temperatures, including the construction of the solid-liquid binary phase diagrams at sub-zero temperatures using differential scanning calorimetry (DSC), hot stage microscopy (HSM) and Raman spectroscopy. The studied systems composed by odd and even n-alkanes, have showed different solid-liquid equilibrium behaviour. The HSM and Raman spectroscopy were fundamental to obtain the binary phase diagrams, but also to visualize the changes taking place in real time as a function of temperature and often the identification of the different solid and liquid phases exhibited by these systems. This work presents some preliminary phase equilibrium data, which, to the knowledge of the authors, are not available in the literature, and are presently being prepared for publication in an international scientific journal. The presentation will also include comparisons with spread literature data, when available. All these studied systems have promising characteristics for low temperature energy storage. With this work, it is also demonstrated how solid-liquid phase equilibrium studies are a central key to select the most adequate phase change material for a specific TES application.