05.1 - Graduação (UACSA)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/2909
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Item FERRAMENTAS LEAN PARA EMPREENDIMENTOS COM SISTEMA DE PAREDE DE CONCRETO ARMADO MOLDADA IN LOCO.(2022-04-13) Nunes, Samuel Hesli de Almeida; Galvão, Simone Perruci; http://lattes.cnpq.br/1523292800241605; http://lattes.cnpq.br/1529726349055934The constructive system of cast-in-place concrete walls is a method in which industrialized forms are used, embedded in the work itself, applied directly with concrete. This is a practically entirely industrialized system. Its great differential compared to traditional constructive models is mainly linked to the leaner cost due to its shorter execution time. With the application of new production methodologies to this system, it is possible to achieve not only the efficiency that the constructive method already promises, but also to propose a continuous improvement to the sector, increasing productivity, eliminating waste and adding value to the product. Within this aspect comes Lean Construction, a philosophy that carries tools and principles that, when properly applied, result in the optimization of processes and deliveries of a quality final product. This work is a study of the bibliographic review in order to investigate, select and propose the application of some tools that follow the principles of the Lean Construction philosophy, to the constructive system of concrete walls, with the intention of cooperating with the improvement of the sector performance. It was found that it is possible to apply Lean tools to the construction method of reinforced concrete walls cast "in loco" and this application brings several benefits to the system, such as: continuous improvement to the construction process; increased transparency of processes; cycle time reduction; increasing the value of products and reducing activities that do not add value. These results can be achieved through the use of tools such as: 5s Program, Andon, Kanban, PDCA Cycle, Physical Arrangement, Last Planner System (LPS), Line of Balance and Value Stream Mapping.Item Desenvolvimento e avaliação de desempenho de um sistema de posicionamento automático de placas fotovoltaicas.(2024-03-05) Santos, Marcos Paulo Jerônimo dos; Aguedo, Reinel Beltrán; http://lattes.cnpq.br/2770313428458626; http://lattes.cnpq.br/7884920585085694The growing demand for renewable energy has driven the development of more efficient and accessible technologies, highlighting photovoltaic energy as one of the main sources of clean energy. However, the efficiency of current solar panels is still insufficient to meet the high en- ergy demand, as it directly depends on the alignment of the solar panels relative to the sun. This research aims to develop a solar tracker prototype and evaluate solar tracking methods as strate- gies to increase the efficiency of photovoltaic panels. Through a comparative analysis, different approaches to automate the positioning of solar panels were explored, including single-axis and dual-axis tracking systems, with and without the use of PID controllers. For this purpose, a testing platform was developed to simulate the sun’s position throughout the day, allowing the prototype to accurately follow the path of the sunlight. Data were collected using a SCADA supervisory system, enabling a detailed and controlled analysis of the efficiency of the different tracking methods, highlighting the superiority of the dual-axis tracker. The results confirm that the use of PID controllers can provide significant gains in energy efficiency.Item Previsão de consumo de energia elétrica no brasil: uma comparação entre métodos(2023-09-22) Fortes, Bruna Lavínia Santos; Ferreira, Felipe Alberto Barbosa Simão; http://lattes.cnpq.br/9939255113143786; https://lattes.cnpq.br/9302922458814221The prediction of electricity consumption plays a crucial role in the effective management of energy resources. This study investigates electricity consumption forecasting methods applied in the Brazilian context. Four widely recognized forecasting techniques were explored: Exponential Smoothing, ARIMA (Autoregressive Integrated Moving Average), Support Vector Machines (SVM), and Artificial Neural Networks (ANN). The analysis began with the decomposition of the time series, allowing for the identification of trends, seasonality, and random variations in the data. The Holt-Winters Exponential Smoothing and the ARIMA model were used to model the underlying temporal aspects. The Support Vector Machines (SVM) technique was enhanced through parameter optimization, resulting in highly accurate and reliable forecasts. Although it required significant computational efforts, SVM demonstrated remarkable capability in capturing complex relationships. ANN was investigated and emerged as the most effective approach, providing exceptionally precise and robust predictions. This method stood out in capturing complex and sequential patterns, making it the preferred choice for forecasting electricity consumption in Brazil. However, the final choice of the model should consider not only evaluation metrics such as MSE (Mean Squared Error), MAE (Mean Absolute Error), and RMSE (Root Mean-Squared Error) but also adaptation to specific data and computational demands.Item Controle vetorial de velocidade em motor de indução trifásico para aplicações em mobilidade elétrica(2024-03-08) Souza, Guilherme Henrique de Carvalho; Méllo, João Paulo Ramos Agra; http://lattes.cnpq.br/2430890141645755; https://lattes.cnpq.br/6351499728705848The replacement of combustion engines with electric motors is already a reality in Brazil. Hybrid and electric vehicles are gaining more market share every day. This is due to their high efficiency, low cost and, above all, the fact that they do not emit polluting gases into the environment. The study of induction motors for vehicle traction has become a challenge for researchers, who are looking for methods and strategies to maximize their market entry. Speed control of electric motors can be carried out in various ways, such as changing the number of poles, vector control, changing the frequency and supply voltage. Vector control is based on the odq variable transform, which is a good representation of the three-phase induction machine in the vector domain. Through this control, it is possible to decouple the machine's conjugate and magnetic flux, allowing each of them to be explored in isolation. The aim of this work is therefore to develop a closed-loop quadrature vector control system for the electric motor used in the Evolt Racing extension project. This study begins by validating the machine model and the open-loop controls, and then closing the control loop. Finally, the motor is driven via PWM inverter and the braking profiles and methods are compared. The simulations were carried out using PSIM and MATLAB software, and the controllers were tuned using the geometric root locus method. It was possible to validate the machine model, tune the controllers to improve the dynamic response and control the motor speed for the permanent regime.Item ESTUDO COMPARATIVO DAS PROPRIEDADES TÉRMICAS, MORFOLÓGICAS E MECÂNICAS DE PA E PLA NA IMPRESSÃO 3D(2024-11-30) Silva, Rafael Aldreem Alves da; Ghislandi, Marcos Gomes; http://lattes.cnpq.br/3409757365313853; http://lattes.cnpq.br/1915012203419619This study conducted a comprehensive characterization of the thermal, morphological, and mechanical properties of poly(lactic acid) (PLA) and polyamide (PA) filaments used in 3D printing, including their carbon fiber (CF) and glass fiber (GF) reinforced variants, as well as specialized versions for high-strength (PRO) and high-temperature (PAHT) applications. Using Differential Scanning Calorimetry (DSC), tensile tests, and Scanning Electron Microscopy (SEM), the thermal behavior, mechanical strength, and internal morphology of the filaments were investigated. The results indicate that PAHT CF15, reinforced with 15% carbon fiber, exhibits the best thermal and mechanical resistance, making it suitable for high-temperature applications. PA6 GF30, with 30% glass fiber, offers a good balance between stiffness and strength. In contrast, PLA White and PLA Pro materials are more suited for moderate- temperature applications. The analysis of different infill patterns (40% and 100%) reveals that the choice of configuration depends on cost-effectiveness, considering the specific application and desired strength. The study suggests that improvements in matrix-fiber adhesion could optimize the performance of the composites, particularly for PAHT CF15.Item ESTUDOS DE PERDAS NOS SEMICONDUTORES E DA DISTORÇÃO HARMÔNICA EM TOPOLOGIAS DE CONVERSORES MULTINÍVEIS(2024-10-03) Silva, João Gonçalves Antunes da; Silva Júnior, Guilherme Penha da; Méllo, João Paulo Ramos Agra; http://lattes.cnpq.br/0439625337029616; http://lattes.cnpq.br/4952843275256497This article presents a study of semiconductor losses and harmonic distortion in multilevel converter topologies. Switching, conduction, and total losses will be analyzed for two-level topologies as well as three- and four-level Neutral-Point Clamped (NPC) topologies at varying frequencies. Additionally, the Total Harmonic Distortion (THD) of the voltage and phase current waveforms will be evaluated. The results include the values of losses and THD for six distinct cases, with variations in standard active and reactive power values, as well as voltage, resistance, and inductance values obtained through simulation. The study also highlights which topology performs better in each case, analyzing scenarios with different voltages and frequencies. The results show that multilevel systems exhibit superior performance at high voltages and elevated frequencies, whereas two-level converters perform better at lower frequencies.Item PROTÓTIPO PARA REAPROVEITAMENTO DA ÁGUA REJEITADA NO PROCESSO DE DESTILAÇÃO(2025-01-30) Lopes, Vinicius Bernard Ramos; Ghislandi, Marcos Gomes; http://lattes.cnpq.br/3409757365313853; http://lattes.cnpq.br/3152723257481776Water is an indispensable natural resource for life on planet Earth. It holds immense environmental, social, and economic value, fundamental to the survival of humans and ecosystems on our planet. Proper water resource management should consider reuse as an integral component, as it not only generates savings but also helps prevent water scarcity. In Brazil, water is primarily used for crop irrigation, public supply, industrial activities, energy generation, mineral extraction, aquaculture, navigation, tourism, and recreation. This study addresses the issue of water waste during the distillation process and is dedicated to developing a system to reuse the rejected water generated during the process, aiming to generate savings and reduce waste. Comparing the two production methods, we can observe that while the usual production method uses approximately 8,580 liters (distilled + waste) of water over 12 months, the proposed production method in this study uses only 627 liters of water, as all the water rejected in the process will be reused for new distillations. The results demonstrated that, due to the significant savings generated by the proposed system compared to the current model, the project can be implemented and replicated in other university laboratories. The findings also highlighted that this water reuse system is an excellent sustainable alternative for managing water resources.Item Desenvolvimento de Estudo de Proteção para Conexão de uma Usina fotovoltaica de 1.194kWp(2023-09-21) Oliveira, Maria Eduarda Araújo de; Alves, Denis Keuton; Ando Júnior, Oswaldo Hideo; https://lattes.cnpq.br/7109075850257262; https://lattes.cnpq.br/8911684468319565The generation of photovoltaic energy presents a different profile from the generation of conventional energy (hydroelectric). This is due to the characteristics inherent to the photovoltaic generation process, such as intermittent generation, in which fluctuations in energy generation occur, adding greater complexity to the protection system. Therefore, this work analyzes current regulations and recommendations for preparing a study on the protection and selectivity of photovoltaic generators. This work used a real case study with a 1MW generator connected to the local utility through a coupling transformer and inverters. The protections and adjustments were selected to assess the reliability of the proposed generator and ensure connection to the distribution network with the minimum quality parameters required by regulations. From the results obtained, it was verified through graphic analysis of the coordination that the method used was effective in the protection and selectivity study, attending to current regulations.Item Estudo da resistência à corrosão do revestimento a base da liga Zn-Ni obtido por eletrodeposição em aço SAE 1020(2023-09-18) Gomes, Anyelle Maria Torres; Santos, Aureliano Xavier dos; http://lattes.cnpq.br/0810494477757052; http://lattes.cnpq.br/9310446438519382Concern for the environment and environmental laws increasingly increase the desire to reduce waste disposal costs, with this in mind, a good alternative is the use of metal biodigesters. However, the organic material and the product of the biochemical process reduce the useful life of this equipment. Aiming for good durability and efficiency of this equipment, studies have been carried out to apply coatings with materials that are highly resistant to corrosion through the electrodeposition process. The objective of this study was to evaluate the corrosion resistance of coatings based on the Zn-Ni alloy obtained by electrodeposition on SAE 1020 steel sheet. The process parameters, bath temperature and current density used to obtain coatings with the alloy Zn-Ni were optimized using factorial experimental design and the results analyzed by the Response Surface Methodology (MSR). The Ni-Zn alloy coatings were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical corrosion measurements by Linear Potentiodynamic Polarization (PPL) and Electrochemical Impedance Spectrometry (EIE). The coating with the alloy Zn68.9Ni31.1 at.%, deposited with current density 25 A/cm2 and bath temperature 60oC, presented the best results against corrosion, as it presented the lowest values of corrosion current, thus indicating a less dissolution of the coating.Item Gesso de revestimento destinado à construção civil reforçado com nanopartículas de óxido de grafeno: análise da resistência mecânica(2024-03-01) Firmino, Daniel Ardiles; Ghislandi, Marcos Gomes; http://lattes.cnpq.br/3409757365313853; http://lattes.cnpq.br/3378137503705619Plaster is a widely used material in civil construction, employed for both structures and general coatings. Graphene Oxide, known for reinforcing structures and being utilized as a reinforcement in civil engineering, is expected to provide additional strength to the structure when incorporated into plaster. This study focused on reinforcing plaster coating with graphene oxide at a concentration of 0.01% by mass, aiming to optimize mass and examine its mechanical properties. A comparison was made between samples with and without oxide addition. The graphene oxide was obtained through the modified Hummers method. Two characterization techniques, X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM), were employed for morphological and structural analysis. Sample preparation adhered to parameters outlined in the NBR 12128 (ABNT, 2019) and NBR 12129 (ABNT, 2017) standards. The results revealed that plaster with added graphene oxide exhibited a reduction of over half in compressive strength compared to plaster without the additional load. SEM images highlighted the accumulation of graphene oxide in specific regions of the plaster, potentially contributing to this decrease in strength.