Percorrer por autor "Pereira, Ana I."
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- 3D printed photopolymer derived carbon catalysts for enhanced wet peroxide oxidationPublication . Silva, Adriano S.; Díaz de Tuesta, Jose Luis; Henrique, Adriano; Roman, Fernanda; Omralinov, Daria; Steldinger, Hendryk; Gläsel, Jan; Etzold, Bastian J.M.; Silva, José A.C.; Silva, Adrián; Pereira, Ana I.; Gomes, HelderIn this paper, we explore the application of powdered carbon and 3D-printed carbon monoliths prepared by carbonization of a tailored photopolymer. We demonstrate the efficiency of the developed carbonaceous samples in removing paracetamol (PCM) and sulfamethoxazole (SMX), used as model contaminants. Our results demonstrate that carbon samples are active in CWPO, and their catalytic activity is significantly improved by applying nitric acid and urea functionalization methods. The characterization results showed the pure carbon nature of the material (no ashes), their unique structure defects proven by Raman (D/G > 1.8), textural properties (SBET = 291–884 m2/g) and their surface chemistry, which was addressed by pHPZC (2.5–7.5), acidity (312–2375 μ mol gcat 1) and basicity (117–653 μ mol gcat 1) determination and XPS of highlighted materials (N1s = 0–3.51 at.%, O1s = 7.1–15.3 at.%). Using desorption assays, our study reveals the adsorption role for pollutant degradation by CWPO using carbon monolithic samples. At last, we demonstrated the ability of functionalized 3D-printed carbon monoliths to keep degradation of PCM and total organic carbon (TOC) above 85 % and 80 %, respectively, during 48 h in a continuous flow CWPO system. Sulfamethoxazole degradation in continuous system was also studied to validate the catalyst versatility, achieving 81 % and 79 % pollutant degradation and TOC abatement, respectively, during 48 h on stream. The characterization of the recovered catalyst provides further insights into the absence of structural modifications after the reaction, reinforcing the stability and reusability characteristic of the 3D-printed carbon catalyst.
- À descoberta de software para explorar a programação linear no ensino secundárioPublication . Barros, Paula Maria; Pereira, Ana I.; Teixeira, Ana P.Na sociedade actual, no quotidiano ou profissionalmente, somos várias vezes confrontados com situações em que temos de tomar decisões de planeamento ou de gestão de forma a rentabilizar os recursos disponíveis e minimizar os custos ou consumos, ou seja, temos de resolver problemas de optimização. Se neste tipo de problemas todas as funções envolvidas (função objectivo e restrições) são lineares estamos perante um problema de Programação Linear (PL). Como uma das finalidades da disciplina de Matemática no Ensino Secundário é desenvolver a capacidade de usar a Matemática como instrumento de interpretação e intervenção no real, torna-se imprescindível que esses alunos explorem também problemas de PL. De realçar, que nos programas em vigor a Programação Linear é um dos temas obrigatórios das disciplinas de Matemática A do 11.º ano e Matemática B do 12.º ano do Ensino Secundário e do módulo A10 (designado por Optimização) do Ensino Profissional. Porém, os problemas reais de PL, e mesmo as suas adaptações, nem sempre são fáceis e rápidos de resolver, pois podem envolver um considerável número de variáveis, pelo que se torna imprescindível o recurso a ferramentas tecnológicas. Estas, para além de constituírem um objecto de motivação e predisposição para a aprendizagem, permitem que os alunos resolvam uma maior diversidade de problemas e se centrem mais na análise e interpretação de resultados. Existem diversos programas de computador como o Solver do Excel, o WinQSB, o Programación Lineal e o Winplot, de acesso livre (na generalidade) e facilmente utilizáveis pelos alunos, que possibilitam a exploração gráfica, no caso bidimensional, ou analítica dos problemas de PL. Nesta comunicação, pretende-se dar uma ideia de como se podem resolver problemas concretos de Programação Linear com esses programas, discutindo, simultaneamente, as suas potencialidades e limitações.
- À descoberta de sofware para explorar a programação linear no ensino secundárioPublication . Barros, Paula Maria; Pereira, Ana I.; Teixeira, Ana P.A Programação Linear, PL, tem como objectivo a resolução de problemas de optimização com restrições em que todas as funções envolvidas são lineares. Diversos problemas da vida real podem ser formulados como problemas de PL como, por exemplo, os problemas de planeamento e de transportes. A Programação Linear é um dos temas obrigatórios de algumas disciplinas de Matemática do Ensino Secundário, sendo importante que se trabalhem com os alunos problemas que traduzam situações reais, ou suas adaptações. Como estes problemas nem sempre são fáceis e rápidos de resolver, a utilização de ferramentas tecnológicas na sua resolução reveste-se de enorme importância. Existem diversos programas de computador como o Solver do Microsoft Office Excel, o WinQSB, o Programación Lineal e o Winplot, de fácil utilização pelos alunos, que possibilitam a exploração gráfica, no caso bidimensional, ou analítica dos problemas de PL. O uso deste software permite que os alunos resolvam uma maior diversidade de problemas e se centrem mais na análise e interpretação de resultados. Neste artigo, ilustra-se, resumidamente, a forma de resolver problemas de PL com o software mencionado e discute-se as suas potencialidades e limitações.
- Accessibility strategies to promote inclusive mobility through multi-objective approachPublication . Silva, Tânia; Verde, David; Paiva, Sara; Barreto, Luis; Pereira, Ana I.In recent decades, urban mobility has assumed a need for adaptation due to the more significant congestion experienced in cities and the growing focus on sustainability. Several solutions are proposed to help citizens move around in an urban environment. Most are not yet aware of the universal and accessible aspect that these solutions must have. This paper proposes a route support system embedded in a mobile application, Viana+Acessivel, using a multi-objective approach. The application aims to promote accessible mobility within the city, contributing to physical and psychological well-being for citizens with reduced mobility, temporary or permanently, such as people with spectrum autism disorder, the visually impaired, wheelchair users, pregnant, and the elderly. For the evaluation of the algorithms, four objective measures were considered: accessibility, slope, time, and length of the paths. The tests carried out with different routing algorithms showed that the A-Star presented the fastest results in terms of execution time compared to the Dijkstra, Floyd-Warshall, and Bellman-Ford. When analysing in a multi-objective approach, time, slope and accessibility were demonstrated to be conflicting objectives. Bi-objective and tri-objective were applied and Pareto front was explored.
- Adaptive path planning for fusing rapidly exploring random trees and deep reinforcement learning in an agriculture dynamic environment UAVsPublication . Castro, Gabriel G.R.; Berger, Guido; Cantieri, Álvaro R.; Teixeira, Marco; Lima, José; Pereira, Ana I.; Pinto, Milena F.Unmanned aerial vehicles (UAV) are a suitable solution for monitoring growing cultures due to the possibility of covering a large area and the necessity of periodic monitoring. In inspection and monitoring tasks, the UAV must find an optimal or near-optimal collision-free route given initial and target positions. In this sense, path-planning strategies are crucial, especially online path planning that can represent the robot’s operational environment or for control purposes. Therefore, this paper proposes an online adaptive path-planning solution based on the fusion of rapidly exploring random trees (RRT) and deep reinforcement learning (DRL) algorithms applied to the generation and control of the UAV autonomous trajectory during an olive-growing fly traps inspection task. The main objective of this proposal is to provide a reliable route for the UAV to reach the inspection points in the tree space to capture an image of the trap autonomously, avoiding possible obstacles present in the environment. The proposed framework was tested in a simulated environment using Gazebo and ROS. The results showed that the proposed solution accomplished the trial for environments up to 300 m3 and with 10 dynamic objects.
- An Artificial Intelligence-Based Method to Identify the Stage of Maturation in Olive Oil MillsPublication . Mendes, João; Lima, José; Costa, Lino; Rodrigues, Nuno; Leitão, Paulo; Pereira, Ana I.Identifying the maturation stage is an added value for olive oil producers and consumers, whether this is done to predict the best harvest time, give us more information about the olive oil, or even adapt techniques and extraction parameters in the olive oil mill. In this way, the proposed work presents a new method to identify and count the number of olives that enter the mill as well as their stage of maturation. It is based on artificial intelligence (AI) and deep learning algorithms, using the two most recent versions of YOLO, YOLOv7 and YOLOv8. The obtained results demonstrate the possibility of using this type of application in a real environment, managing to obtain a mAP of approximately 79% with YOLOv8 in the five maturation stages, with a processing rate of approximately 16 FPS increasing this with YOLOv7 to 36.5 FPS reaching a 66% mAP.
- An automatic method to track red blood cells in microchannelsPublication . Pinho, Diana; Gayubo, Fernando; Pereira, Ana I.; Lima, Rui A.Image analysis is extremely important to obtain crucial information about the blood phenomena in micro-circulation. The current study proposes an automatic method for segmentation and tracking red blood cells (RBCs) flowing through a 100 μm Glass capillary. The original images were obtained by means of a confocal system and then processed in Matlab using the Image Processing Toolbox. The automatic measurements ob-tained with the proposed automatic method are compared with a manual tracking method using a plugin from ImageJ.
- An improved GA-based approach for reduced non-discriminatory renewable energy curtailmentPublication . Pedroso, André Felipe Pereira; Zanatta, Giuseppe; Ferreira, Ângela P.; Pereira, Ana I.; Amoura, Yahia; Lopes, Rui Pedro; Angelos, Eduardo Werley S. dos; Vasconcelos, Fillipe Matos de; Lemos, Manuel; Pino, GabrielThe active management of the networks with high penetration of renewable energy sources faces several challenges. To maximize the utilization of low carbon electricity, the curtailment of generator units using renewables should be limited and fair among units. In this work, an attempt has been made to solve the optimal power flow using an improved Genetic Algorithm. The optimal flow formulation is oriented to the efficiency of the network, under the boundary restrictions of limited curtailment of the output of distributed generators based on renewables and non-discriminatory behaviour. The results obtained from a IEEE 14-bus test system have demonstrated the feasibility of this approach.
- An improvement of genetic algorithm based on dynamic operators rates controlled by the population performancePublication . Azevedo, Beatriz Flamia; Pereira, Ana I.; Bressan, GlauciaThis work presents a hybrid approach of genetic algorithm with dynamic operators rates that adapt to the phases of the evolutionary process. The operator’s rates are controlled by the amplitude variation and standard deviation of the objective function. Besides, a new stopping criterion is presented to be used in conjunction with the proposed algorithm. The developed approach is tested with six optimization benchmark functions from the literature. The results are compared to the genetic algorithm with constant rates in terms of the number of function evaluations, the number of iterations, execution time and optimum solution analysis.
- An innovative optimization approach for energy management of a microgrid systemPublication . Amoura, Yahia; Pereira, Ana I.; Lima, José; Ferreira, Ângela P.; Boukli-Hacene, Fouad; Torres, SantiagoThe local association of electrical generator including renewable energies and storage technologies approximately installed to the client made way for a small-scale power grid called a microgrid. In certain cases, the random nature of renewable energy sources, combined with the variable pattern of demand, results in issues concerning the sustainability and reliability of the microgrid system. Furthermore, the cost of the energy coming from conventional sources is considering as matter to the private consumer due to its high fees. An improved methodology combining the simplex-based linear programming with the particle swarm optimisation approach is employed to implement an integrated power management system. The energy scheduling is done by assuming the consumption profile of a smart city. two scenarios of energy management have been suggested to illustrate the behaviour of cost and gas emissions for an optimised energy management. The results showed the reliability of the energy management system using an improvemed approach in scheduling of the energy flows for the microgrid producers, limiting the utility’s cost versus an experiment that had already been done for a similar system using the identical data. The outcome of the computation identified the ideal set points of the power generators in a smart city supplied by a microgrid, while guaranteeing the comfort of the customers i.e without intermetency in the supply, also, reducing the emissions of greenhouse gases and providing an optimal exploitation cost for all smart city users. Morover, the proposed energy management system gave an inverse relation between economic and environmental aspects, in fact, a multi-objective optimization approach is performed as a continuation of the work proposed in this paper