https://repositorio.unifei.edu.br/jspui/handle/123456789/56 Fri, 30 Oct 2026 00:13:12 GMT 2026-10-30T00:13:12Z https://repositorio.unifei.edu.br/jspui/handle/123456789/4337 Nanopartículas híbridas termossensíveis baseadas em proteína-polímero como um potencial sistema carreador de agentes terapêuticos contra o câncer In recent years, hybrid materials combining proteins and polymers have attracted significant interest in the biomedical field, particularly in the development of controlled drug delivery systems. The conjugation of these two classes of materials enables the integration of biocompatibility, stability, and functionality into a single system. Among natural proteins, silk fibroin (SF) stands out as a promising biocompatible material, while poly(N-vinylcaprolactam) (PNVCL) offers a thermoresponsive behavior suitable for therapeutic applications. In this context, the SF–PNVCL hybrid system emerges as an innovative strategy for the development of nanocarriers capable of responding to specific stimuli, such as temperature increases, thereby optimizing the release of therapeutic agents. In this work, novel thermoresponsive hybrid systems based on silk fibroin (SF) and PNVCL were developed, aiming to produce nanoparticles capable of promoting controlled release of therapeutic agents, using curcumin as a model drug. The hybrid systems were synthesized using a grafting-from strategy via reversible addition-fragmentation chain-transfer (RAFT) polymerization, through the functionalization of fibroin with chain transfer agents (CTA1 and CTA2). A second synthetic route was established by activating CTA2 with pentafluorophenol (PFP). The systems were characterized by Fouriertransform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and powder X-ray diffraction (PXRD). The nanoparticles were further evaluated by dynamic light scattering (DLS), zeta potential measurements, and transmission electron microscopy (TEM). The results revealed that the hybrid systems exhibited nanoparticulate morphology (~200 nm), good colloidal stability, and a thermoresponsive phase transition near 40 °C. Additionally, the nanoparticles demonstrated curcumin encapsulation efficiency of approximately 40%, with enhanced release at elevated temperatures. The release kinetics showed a better fit to the Weibull and Gompertz models (R² > 0.99), indicating a controlled and thermoresponsive release process. In vitro cytotoxicity assays, evaluated by flow cytometry, revealed low toxicity in normal cells (MRC-5) and high selectivity toward the 4T1 cancer cell line, with up to 49.5% cell inhibition. Based on these findings, SF– PNVCL hybrid systems represent a promising platform for the development of smart carriers for targeted therapeutic applications. Tese Tue, 09 Dec 2025 00:00:00 GMT https://repositorio.unifei.edu.br/jspui/handle/123456789/4337 2025-12-09T00:00:00Z https://repositorio.unifei.edu.br/jspui/handle/123456789/4336 Deposição via brasagem indireta de revestimentos cerâmicos em interconector metálico de aço inoxidável ferrítico 444 aplicado em pilhas a combustível de óxido sólido In this work, ferritic stainless steel 444 was coated with ceramic films of MnCo2O4 and MnFe2O4 for application as interconnects in Solid Oxide Fuel Cells (SOFCs) through indirect brazing. The synthesis of the spinel-structured oxides MnCo2O4 and MnFe2O4 was evaluated via microwave hydrothermal technique, using low values of time and temperature. The synthesis parameters aimed to produce ceramics with the lowest resistivity. Only the cobaltite samples synthesized at 100 and 130°C for 5 minutes achieved a single phase; other synthesis parameters resulted in phases originating from intermediate reactions. After sintering, samples synthesized at 130°C for 5 minutes showed the lowest conductivity values: 669.7 Ω⁻¹cm⁻¹ and 6513.7 Ω⁻¹cm⁻¹ at 200°C for ferrite and cobaltite, respectively. The chosen ceramics were impregnated with titanium metal via wet impregnation to improve the interaction between the ceramic and the brazing alloy, enhance electrical resistance, and achieve a closer thermal expansion coefficient to that of the base metal to be coated. The wet impregnation process using TiH2 as the metal source proved feasible for both ceramics, resulting in ceramic particles “decorated” with titanium particles, as confirmed by the reduction in their band gap energy. The use of a brazing alloy with a melting temperature of 700°C limited the sintering temperature of the films, preventing the achievement of film densification values and the establishment of metal/ceramic bonding points, both with and without impregnation. The use of metal impregnation techniques proved possible in this work and is a promising method for applications not only in metal/ceramic joining but also in areas such as photocatalysis, electrocatalysis, and sensor fabrication. Tese Wed, 17 Dec 2025 00:00:00 GMT https://repositorio.unifei.edu.br/jspui/handle/123456789/4336 2025-12-17T00:00:00Z https://repositorio.unifei.edu.br/jspui/handle/123456789/4325 Proposta de sistemática para o processo de autoavaliação: uma contribuição para a avaliação e acompanhamento dos programas de pós-graduação profissionais Brazilian graduate education is continuously seeking to refine its evaluation models to better assess its programs. In this context, self-evaluation (SE) stands out as a fundamental criterion for the continued accreditation of stricto sensu Postgraduate Programs, fostering internal improvements and alignment with the guidelines of the Coordination for the Improvement of Higher Education Personnel (CAPES). This work investigates SE practices in professional postgraduate programs (PGPs) within a Higher Education Institution (HEI), aiming to enhance these practices and align them with CAPES's expectations. Therefore, the objectives of this work consist of analyzing the context of Brazilian postgraduate education and the evaluation criteria pertaining to SE; describing and analyzing the SE practices in the HEI's professional PGPs and in a benchmark program; mapping documents and regulations regarding SE, establishing criteria for comparison and validation; and proposing improvements to the SE practices, based on the literature, CAPES guidelines, and best practices. The methodology, qualitative, exploratory, and descriptive, employs a multiple case study involving five PGPs from the HEI and a benchmark program. Document analysis encompasses legislation, CAPES regulations and guidelines, institutional documents, and public information from the Sucupira Platform. The results reveal heterogeneity in SE implementation, ranging from initial stages to more consolidated practices. Comparison with the benchmark program highlights the importance of aligning SE with strategic planning, stakeholder participation, consistent reporting and dissemination, and the use of results for continuous improvement. Furthermore, the study proposes an analytical framework with twelve items and characteristics for evaluating SE practices, categorized into four maturity stages. This research contributes to advancing knowledge about SE in PGPs by offering a methodology for analyzing and improving processes, thus strengthening self-evaluation in postgraduate education. Dissertação Tue, 01 Jul 2025 00:00:00 GMT https://repositorio.unifei.edu.br/jspui/handle/123456789/4325 2025-07-01T00:00:00Z https://repositorio.unifei.edu.br/jspui/handle/123456789/4324 Detecção de faltas de alta impedância em sistemas de distribuição utilizando transformada Wavelet e modelos de aprendizado de máquina The identification of high-impedance faults is a recurring topic in the literature, given the importance of electric power in modern life and the disruptions caused by its absence. High-impedance faults are difficult to identify, presenting peculiarities and characteristics that can easily be mistaken for simple load variations in electrical systems. Conventional methods, such as those used in protection relays, may fail to correctly identify high impedance faults, delaying system restoration. The problems associated with delayed identification can have both economic impacts and pose safety risks to living beings. Therefore, considering the advancements in computational methods and their contribu tions to solving problems across various fields, the objective of this work is to apply these methods to the identification of high-impedance faults. To achieve this, machine learn ing algorithms were employed in combination with the Continuous Wavelet Transform (CWT) to analyze simulated electrical signals in IEEE 13-bus and 34-bus systems. The results showed improvements in the accuracy and precision of fault detection compared to existing methods in the literature, validating the effectiveness of the proposed approach. Dissertação Sat, 19 Apr 2025 00:00:00 GMT https://repositorio.unifei.edu.br/jspui/handle/123456789/4324 2025-04-19T00:00:00Z