https://repositorio.unifei.edu.br/jspui/handle/123456789/55 Mon, 15 Jun 2026 10:03:02 GMT 2026-06-15T10:03:02Z https://repositorio.unifei.edu.br/jspui/handle/123456789/3173 Aquisição e validação de sinal de ruído eletroquímico Corrosion is a global problem, which implies costs in industrialized countries of up to 4.5% of GDP, with either economic, but also social and environmental impacts. In the case of Brazil, the waste of water supply networks due to leaks loss is quite significant and much of it is caused by network degradation, indicating that corrosion control should be promoted whenever possible. This study proposes a corrosion monitoring system, in system subject to the use of inhibitor, with the approach of passive technique for monitoring corrosion by electrochemical noise (EN), in which the classification of events in a corrosion sensor by EN is part of methodological study for structural integrity (or “health”) monitoring system (SHM). Due to very dynamic and stochastic nature of the signal, this study and analysis of EN measurements (ENM) considers numerical and graphic characteristics of two corrosion systems both in saline aqueous solution: carbon steel and stainless steel. These experiments are repeated for accumulating data, which allow the generation of several graphs in time and frequency domains, from which at least one characteristic is extracted, which has a good correlation with data from corrosion processes. Then, based on a supervised machine learning system, the training data allows the model to be calibrated. From the test data, the correctness rate of the model above 50% is verified. Dissertação Thu, 17 Feb 2022 00:00:00 GMT https://repositorio.unifei.edu.br/jspui/handle/123456789/3173 2022-02-17T00:00:00Z https://repositorio.unifei.edu.br/jspui/handle/123456789/4440 Otimização via simulação aplicada à logística reversa The growth of waste electrical and electronic equipment (WEEE) poses economic, environmental, and social challenges to the planning of reverse logistics (RL). This study proposes and applies a Simulation-based Optimization (OvS) approach to support vehicle routing and fleet allocation in a Heterogeneous Fleet Vehicle Routing Problem (HFVRP), balancing cost, CO₂ emissions, and collection volume. The method integrates: (i) data preparation (distance matrices, demands, and costs, as well as vehicle characteristics); (ii) generation of solutions by a multi-objective Genetic Algorithm (GA); and (iii) stochastic evaluation through discrete-event simulation (FlexSim), without re-optimization. The social dimension was operationalized exclusively as the total collected quantity (kg) and service coverage, with an additional link to “perishable food”: for every kilogram of waste collected, one kilogram of perishable food would be donated to charitable organizations. A total of 20 scenarios from the GA’s non-dominated frontier were evaluated. In Case 1, which involved municipalities of the Metropolitan Region of São Paulo, one scenario (9) proved invalid during simulation and was excluded from the final comparison. Among the valid ones, informative extremes were observed: the lowest cost was R$ 626.53 (Scenarios 13 and 14), with 78.01 kg CO₂ and 7,366.74 kg collected; the lowest emissions were 74.24 kg CO₂ (Scenarios 8 and 10), both with R$ 631.38 and 7,366.74 kg collected; and the largest collection reached 15,979.03 kg (Scenario 20), with a cost of R$ 2,137.76 and 270.21 kg CO₂. In the weighted sum analysis (min–max normalization), Scenario 20 stood out when emissions and collection were jointly prioritized, whereas Scenario 10 emerged as a balanced solution (low cost, minimum emissions, and intermediate collection). In Case 2, designed with distinct fleet parameters, capacities, and distance matrices, the goal was to evaluate the robustness and scalability of the model. The results confirmed that the tool preserved the consistency of the trade-offs identified in the first case, adapting to alternative operational conditions without loss of coherence. The comparative analysis demonstrated that the method is applicable across diverse operational realities, thereby expanding its practical potential in reverse logistics. It is concluded that OvS combined with a multi-objective GA responds positively to the problem: it filters infeasible solutions, makes trade-offs explicit, and delivers an auditable portfolio of alternatives for WEEE reverse logistics, aligning economic, environmental, and service coverage goals. The computational tool developed constitutes a replicable basis for practical adoption and for future extensions. Tese Tue, 30 Sep 2025 00:00:00 GMT https://repositorio.unifei.edu.br/jspui/handle/123456789/4440 2025-09-30T00:00:00Z https://repositorio.unifei.edu.br/jspui/handle/123456789/4439 Modelo de referência para desenvolvimento de produtos no setor de embalagens plásticas com foco na economia circular The vast majority of companies currently operate within a linear economy framework, where production, consumption, and disposal constitute the fundamental pillars of their business models. This traditional system frequently overlooks resource regeneration. Conversely, the circular economy emerges as an approach that challenges this paradigm by prioritizing sustainability, waste reduction, and the retention of products, materials, and resources in use for as long as possible. Facing this transition toward a circular economy, companies are challenged to redesign their product development processes, as products must be "born circular." This challenge becomes particularly relevant in the plastic packaging sector, which is characterized by high consumption of virgin materials, short functional product lifespans, and significant environmental impacts associated with improper disposal. Although various industrial sectors present specific product development process models, many of these frameworks still do not systematically integrate Circular Economy principles. In this context, this thesis proposes and validates a reference model for plastic packaging development focused on the circular economy, structured around Cooper’s Stage-Gate logic and integrated with Circular Economy practices, tools, and criteria throughout the Product Development Process (PDP). The model operationalizes circularity within the PDP by incorporating decisions related to material reduction, the use of post-consumer recycled (PCR) content, design for recycling, reuse, disassembly, traceability, reverse logistics, and post-launch indicators. The development of the model was grounded in a comprehensive study of circular economy principles and product development practices. To validate its suitability and applicability, a case study methodology was adopted, analyzing two companies within the plastic packaging sector selected based on predefined criteria to ensure segment representativeness. Data collection was conducted through a structured questionnaire, specifically designed to capture information regarding circular economy practices across the different stages of the product development process. The cross-case analysis allowed for an assessment of the degree to which circular economy principles are incorporated within the studied companies, identifying convergences, limitations, and opportunities for improvement, as well as verifying the adherence of the proposed model to the analyzed industrial context. The results demonstrate that circularity cannot be integrated late or in an ad-hoc manner; rather, it must be conceived from the early stages of development. As its main scientific and applied contribution, this thesis presents a validated reference model for the development of circular plastic packaging, helping to bridge the gap between the conceptual principles of the Circular Economy and their practical operationalization within the Product Development Process. Tese Mon, 04 May 2026 00:00:00 GMT https://repositorio.unifei.edu.br/jspui/handle/123456789/4439 2026-05-04T00:00:00Z https://repositorio.unifei.edu.br/jspui/handle/123456789/4438 Estudo das interações intermoleculares de ciclodextrinas com fármacos antidiabéticos Metformin hydrochloride (MET) and phenformin hydrochloride (FEN) are antihyperglycemic drugs belonging to the biguanide class, with MET being a first-line therapy for the treatment of type II diabetes mellitus (DMII). MET is limited by its low bioavailability, whereas FEN was withdrawn from the market due to adverse side effects associated with its use. Cyclodextrins (CDs) are of great interest to industry, particularly the pharmaceutical sector, because of their ability to modify intrinsic drug properties such as solubility, stability, and bioavailability. The aim of this study was to investigate the thermodynamic parameters involved in the interactions between the drugs FEN and MET and natural cyclodextrins (α-CD, β-CD, and γ-CD), as well as modified cyclodextrins (CM-β-CD, HP-β-CD, and M-β-CD), and to structurally characterize the compounds formed. Thermodynamic parameters were determined using isothermal titration calorimetry (ITC); additionally, the effect of temperature variation was evaluated for the FEN:CM-β-CD system. Solid-state inclusion compounds were obtained by freeze drying. The inclusion compounds were characterized by vibrational spectroscopy in the infrared region (FTIR-ATR), and inclusion was confirmed by one- and two-dimensional 1H NMR experiments. By comparing the systems formed by MET and FEN using calorimetric titration, it was possible to verify that the presence of an aromatic ring in the FEN structure favored the formation of inclusion compounds with α-CD, β-CD, and CM-β-CD. Based on the 1H NMR results, the formation of inclusion compounds was confirmed for the FEN:β-CD and FEN:CM-β-CD systems, and possible structures for the complexes formed were proposed. Dissertação Fri, 13 Mar 2026 00:00:00 GMT https://repositorio.unifei.edu.br/jspui/handle/123456789/4438 2026-03-13T00:00:00Z