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Seleção de modelos de associação RC utilizando reversible jump MCMC
(Universidade Federal de São Carlos, 2025-06-09) Ferreira, Flávio Fagundes; Milan, Luis Aparecido; https://lattes.cnpq.br/7435391829973844; https://orcid.org/0000-0001-6466-7865; https://lattes.cnpq.br/4467235193229795; https://orcid.org/0000-0001-5408-5415; Demétrio, Clarice Garcia Borges; https://lattes.cnpq.br/7923944433659347; https://lattes.cnpq.br/1890753837146343; https://lattes.cnpq.br/8916772290938469; https://lattes.cnpq.br/8952048121396398; https://orcid.org/0000-0002-3609-178X; https://orcid.org/0000-0002-4698-4004; https://orcid.org/0000-0002-1041-2768
The RC (Rows and Columns) association model of order K applied in contingency table analysis provides the values of the parameter estimates that evaluate the degree of association between the categories of the variables arranged in rows and columns of the table. We propose a new methodology for estimating the order K of the association model using Bayesian inference and reversible jump by MCMC (RJMCMC). In the graphics, we illustrated the groupings through credible intervals to confirm the results obtained by RJMCMC. We applied the proposed methodology to simulated data to validate the method and also to data from previous studies for comparison purposes, and the results were convergent. We subsequently we applied the proposed methodology to three real databases to assess the performance of Enem 2023 participants in the language, mathematics and writing tests according to their father’s and mother’s education. We conclude that there is an association between some categories performance and education. There is a graphical indication of grouping of rows and columns both in the results with simulated data and in the results of the comparative study.
Design, fabrication and characterization of Fe-based bulk metallic glass composites by additive manufacturing
(Universidade Federal de São Carlos, 2025-06-09) Araújo, Aylanna Priscila Marques de; Gargarella, Piter; https://lattes.cnpq.br/4641435644243916; https://orcid.org/0000-0003-4445-5819; https://lattes.cnpq.br/1742937906045551; https://orcid.org/0000-0001-7187-9647
Bulk Metallic Glasses (BMGs) possess unique properties such as high strength, large elastic limits, excellent magnetic behavior, and corrosion resistance, primarily due to their disordered atomic structure. However, their limited ductility at room temperature, caused by nonhomogeneous deformation, restricts widespread use. To overcome this, Bulk Metallic Glass Composites (BMGCs), which incorporate a ductile second phase into a glassy matrix, offer enhanced ductility while retaining strength. Among BMGs, Fe-based alloys are particularly attractive due to their favorable magnetic, mechanical, and corrosion-resistant properties and low cost. Yet, their poor glass-forming ability (GFA) and need for rapid cooling rates limit practical applications and component size and geometry. This study explores the feasibility of using Laser Powder Bed Fusion (LPBF), an additive manufacturing method offering high cooling rates (103-106 K/s), to fabricate Fe-based BMGCs in the Fe-Mo-P-C-B system. Six alloy compositions were designed through theoretical modeling and synthesized via arc melting. The most promising alloys, selected through microstructural and mechanical evaluation, were scaled up using Vacuum Induction Melting (VIM) and then gas atomized to produce powders suitable for LPBF. The atomized powders were processed by LPBF under various parameters to produce dense samples with retained glassy phase. While process optimization reduced defects (cracks and pores down to 1%) and achieved glassy phase fractions up to 24%, these conditions were not simultaneously met. The microstructure included ultrafine bcc Fe-Mo-C grains in the melt pool and mixed crystalline phases in the heat-affected zone. Compression tests showed no plastic deformation, but the LPBF samples demonstrated excellent wear resistance, combining low coefficients of friction and wear rates. Overall, the study reveals the trade-off between high density and glass formation in LPBF-fabricated Fe-based BMGCs, highlighting both the potential and the challenges of using additive manufacturing for producing such advanced materials.
A repercussão do vitiligo no cotidiano: uma questão para a terapia ocupacional
(Universidade Federal de São Carlos, 2025-06-09) Garbuio, Lívia Martins; Aguiar, Laysla Demonari; https://lattes.cnpq.br/6759395773791257; https://orcid.org/0000-0003-0691-8739; Marcolino, Taís Quevedo; https://lattes.cnpq.br/7197838515800679; https://orcid.org/0000-0002-9694-5118; https://lattes.cnpq.br/4173916968046437; https://orcid.org/0009-0000-1952-0696
Vitiligo is a chronic, acquired, and generally progressive systemic disease characterized by the appearance of achromic spots on areas of the skin due to the absence of melanin. Although vitiligo does not cause physical disability, it can have a significant psychosocial impact. Considering that emotional and mental health aspects have an impact on people's daily lives, occupational therapy can be presented as a comprehensive care approach for the person. Although occupational therapy is a common therapeutic proposal for several chronic health conditions, there are few studies that directly address the care of people with chronic dermatological problems, such as vitiligo. This is an exploratory and descriptive research, with a case study approach, involving qualitative and qualitative methodology. People with vitiligo who are undergoing occupational therapy treatment or who have been undergoing treatment were invited to participate via social media. One person actually participated. Data were produced through a characterization questionnaire, a semi-structured interview, and the application of two instruments of social participation and quality of life. Quantitative data were analyzed descriptively, and qualitative data were analyzed thematically. The results of this research showed that living with vitiligo has repercussions on daily life, limiting the performance of activities in which the spots are visible, and triggering coping strategies that minimize the effects of stigma. Given the diverse impacts of living with vitiligo on daily life, occupational therapy can be considered a care strategy with the potential to promote greater integration between who the person with vitiligo is and their potential to perform activities and participate socially, in addition to facing the stigmas of the disease. Thus, this study opens new questions for research that seeks to understand the effects of vitiligo on daily activities, as well as on specific care strategies in our field.