Federal Center for Technological Education of Minas Gerais

In this work, we investigate the quantum information dynamics of the Dirac oscillator (DO) influenced by the Aharonov–Casher (AC) effect in the curved space–time of a cosmic string. By combining relativistic quantum mechanics with geometric and topological effects, we analyze how these elements modify key quantum information measures, namely, the Shannon entropy and Fisher information, thereby uncovering their role in shaping the probability and density distributions of the system. The study reveals how the interplay between the cosmic string geometry and the nontrivial spin–field coupling induced by the AC phase affects the informational content and localization of quantum states. These results offer new insights into the sensitivity of relativistic quantum systems to space–time topology and electromagnetic interactions, contributing to the broader understanding of information-theoretic aspects in curved backgrounds.

This paper presents a comparative analysis of direct expansion solar-assisted heat pumps (DX-SAHP) with and without photovoltaic cells (PVT-DX-SAHP). Two sets of experiments were conducted to validate the mathematical model: one with PVT-DX-SAHP and another with DX-SAHP. The mathematical model used in this study is based on physical equations using energy, mass, and entropy balance. The heat exchangers were modeled using the moving boundaries technique. The compressor and photovoltaic cells were modeled using a black box model with equations for the efficiencies of these components. The low-global-warming-potential (GWP) refrigerant R290 (propane) was used in this study. Two independent sets of experimental data were used to validate the model, with a mean absolute deviation of 4.8%. The results indicated that PVT-DX-SAHP had a higher season performance factor (SPF) and a lower total equivalent warming impact (TEWI) compared to DX-SAHP, with an average SPF increase of 81% and a TEWI reduction of 30%. The findings also showed that PVT-DX-SAHP had a 24% higher longer payback period than DX-SAHP.

A gestão patrimonial tem como finalidade organizar, estruturar, fiscalizar e zelar pela preservação e utilização eficiente dos bens públicos. Este estudo investiga a produção científica sobre gestão patrimonial publicada na plataforma SPELL entre os anos de 2020 e 2024. A pesquisa revelou que, apesar da importância da gestão patrimonial, o tema tem sido subexplorado na literatura acadêmica, com apenas 35 artigos tidos como relevantes. Embora existam legislações e normas que regulamentam a gestão patrimonial no serviço público, a falta de estudos acadêmicos sobre o tema destaca a necessidade de mais pesquisas. Recomenda-se a realização de estudos de caso detalhados em instituições públicas para compreender os desafios específicos e as soluções adotadas em processos de tomada de decisão que envolvam a gestão patrimonial. Essas abordagens mais aprofundadas poderão contribuir significativamente para melhorar a gestão patrimonial no setor público e, consequentemente, para aperfeiçoar a eficiência na prestação de serviços públicos. Palavras-chave: Análise Bibliométrica. Gestão Patrimonial. Tomada de Decisão. ABSTRACT The patrimonial management has the purpose to organize, structure, supervise and ensure preservation and efficient use of public goods. This study investigates the scientific production on patrimonial management published on the SPELL platform between 2020 and 2024. The research revealed that, despite the importance of patrimonial management, the topic has been underexplored in the academic literature, with only 35 relevant articles identified. Although there are laws and regulations that control the patrimonial management in the public sector, the lack of academic studies about the subject highlights the need for more research. Detailed case studies are recommended in public institutions to understand the specific challenges and solutions adopted in decision making processes involving patrimonial management. These deeper approaches could significantly contribute to improving the patrimonial management in the public sector and, consequently, the efficiency of public services. Keywords: Bibliometric Analysis. Patrimonial Management. Decision Making.

3D printing, or additive manufacturing, has emerged as a versatile technology enabling the efficient fabrication of complex, customized components. However, despite its numerous advantages, the long-term durability of printed parts, particularly under humid conditions, remains a key concern, especially for polymer-based materials like polylactic acid (PLA). Previous studies have demonstrated that water diffusion into PLA is influenced by environmental parameters such as temperature, humidity, or its molecular structure. Yet, classical diffusion models, which assume homogeneous materials, fail to capture the layered and anisotropic nature of 3D-printed structures. In this study, the role of interlayer interfaces in water diffusion and mechanical degradation in PLA components fabricated by fused deposition modeling (FDM) is investigated. A combination of theoretical modeling and experimental testing is used to assess the influence of interface density on moisture uptake and adhesion strength. The results demonstrate that water diffusion and mechanical degradation are both strongly influenced by the number and properties of interlayer interfaces. The diffusion model was validated by comparing its predictions with gravimetric measurements across four layer-height configurations, showing excellent agreement. This study provides new insights into the ageing mechanisms of 3D-printed PLA parts and suggests design strategies to improve their performance in humid environments.

ABSTRACT This study investigated the stability of dam slopes built with tropical soils, focusing on the effects of wave action and rapid drawdown with the aim of testing the physical scale model. A 1:30 scale physical model was developed using a lateritic clayey tropical soil from Ouro Preto, MG, classified as MH (SUCS) and LG' (MCT). The models were subjected to controlled wave generation (varying height and period) and rapid water level drawdown. Monitoring included moisture sensors, 3D laser scanning for erosion assessment, and water turbidity measurements. Results revealed that progressive surface erosion, saturation-induced instability, and localized failure from rapid drawdown are the predominant failure mechanisms. A direct relationship was found between wave height and erosion rate, with critical wave heights above 1.8 m (real scale) inducing accelerated erosion. The study provides technical data for designing safer hydraulic structures with tropical soils against extreme hydrodynamic events.

The draw-bend fracture (DBF) test was used to simulate the different forming conditions of AISI 430 steel strips with thickness of 0.8 mm. The tests were performed for varying test parameters such tool radius, drawing speed and strip orientation. The analysis of variance (ANOVA) at α = 0.05 significance level was used to determine the relationship between the test parameters and the major strain, the total elongation and the thickness reduction of samples as well as the coefficient of friction. A comparative analysis of the DBF test results revealed that parameters related to specimen deformation changed with an increasing tool radius to thickness (R/t) ratio. However, no statistically significant effect of drawing speed or strip orientation on major strain and thickness reduction was observed. The value of total elongation increased with increasing R/t ratio. An increase in drawing speed resulted, for both analyzed strip orientations, in a reduction of the coefficient of friction. Over the entire range of analyzed sliding speeds and R/t ratios, the coefficient of friction for sheets oriented along the sheet rolling direction was higher than that for specimens cut in the transverse direction.

Abstract Existing studies on high-strength steel (HSS) column stability have mainly focused on rolled or conventionally welded members. The effect of flame-cut flanges and the associated residual stress distributions on the global buckling resistance of welded I-shaped sections remains insufficiently quantified in current design standards. This study investigates the global buckling behavior of welded HSS I-section columns with flame-cut flanges under axial compression using finite element analysis accounting for geometric and material nonlinearities, residual stresses, and initial imperfections. Parametric studies were conducted on 460 MPa and 690 MPa steel columns across a range of slenderness ratios and cross-sectional dimensions. A comparison between the obtained results and the ANSI/AISC 360-16 and EN 1993-1-1 curves shows that EN 1993-1-1 predictions are generally conservative, while the AISC curve agrees well for normalized slenderness up to 1.5, though it overestimates minor-axis buckling capacity for 460 MPa columns. Three new design curves were calibrated using numerical results, showing improved accuracy in predicting buckling behavior. These findings provide a basis for developing more reliable and less conservative design provisions for HSS columns.