Repositório UFSCar

O Repositório Institucional da UFSCar (RI UFSCar) é um sistema de informação que visa armazenar, preservar, organizar e disseminar amplamente a produção intelectual dos diversos setores e segmentos da comunidade da UFSCar, provendo o acesso aberto à informação produzida na instituição e registrada como científica, tecnológica, didática, artístico-cultural e técnico-administrativa.

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Submissões Recentes

Estudo da razão de refino de malhas numéricas usadas na simulação de separadores supersônicos
(Universidade Federal de São Carlos, 2026-07-07) Miné, Felipe Tobias Cesar; Augusto, Liliana de Luca Xavier; http://lattes.cnpq.br/6049769741255261; https://orcid.org/0000-0002-4802-4269; Lopes, Gabriela Cantarelli; http://lattes.cnpq.br/5680967191791061; https://orcid.org/0000-0002-4475-6075
Supersonic separators constitute a promising alternative to conventional phase separation methods as they dispense with moving parts and external heating, reducing maintenance costs and energy consumption. However, experimental tests are costly, which makes computational simulations essential tools for optimizing these devices. The work fills a gap in the literature by comparing approaches for mesh construction for supersonic separators, investigating the influence of mesh refinement strategy on the accuracy and efficiency of supersonic flow simulations in a convergent-divergent nozzle. Two approaches are compared: uniform refinement in the axial and radial directions (Group 1) and exclusively axial refinement (Group 2). Five response variables are analyzed: shock wave position, minimum pressure, maximum velocity, minimum temperature, and mass flow rate. The results indicate that Group 1 presents greater accuracy, with lower values of the Grid Convergence Index (GCI) for all variables. Group 2, in turn, converges more quickly, with a total simulation time 24% lower, especially for less refined meshes. The mass flow rate presents the smallest errors (GCI < 0.1% in Group 1) as it is little influenced by compressibility; the minimum pressure proves to be the most sensitive variable, with errors up to 33% in Group 2 for coarse meshes. It is observed that uniform refinement is recommended when accuracy is a priority, while anisotropic refinement can be adopted in exploratory studies or under time constraints, provided that larger errors are tolerated.
Monitoramento do desgaste de ferramentas de usinagem de painéis sanduíche por meio de análise de vibrações e microscopia
(Universidade Federal de São Carlos, 2026-06-11) Perruci, Marcelo de Jesus; Shiki , Sidney Bruce; http://lattes.cnpq.br/0573973677787523; https://orcid.org/0000-0001-9373-3630; https://lattes.cnpq.br/3785044141613175; Antonialli, Armando Ítalo Sette; Castillo, Pedro Christian Ayala; http://lattes.cnpq.br/4367459395417045; http://lattes.cnpq.br/1523874172713616; https://orcid.org/0000-0002-3466-0416; https://orcid.org/0000-0003-0236-0643
The application of composite materials has expanded across various areas of modern industry, driven by the search for lighter and stronger components. These materials exhibit characteristics such as high specific stiffness, corrosion resistance, and low mass, making them attractive to sectors such as automotive, naval, sports, wind energy, and biomedical segments. However, it is in the aeronautical industry that composite materials have the most significant use, being employed in the manufacture of fuselages, wings, and internal components, with the main purpose of reducing the total weight of aircraft, promoting greater fuel efficiency, increased flight range, and reduced emissions. The processing of these materials is largely carried out by CNC machining centers, equipped with cutting tools developed to handle the abrasiveness and heterogeneity of composites. Such tools have high development and acquisition costs and are subject to accelerated wear during the process, which reinforces the need for strategies that allow for maximum utilization of their service life without compromising the quality and integrity of the final product. In this context, this study proposes monitoring the condition of cutting tools through a combination of direct and indirect methods. The direct method employs geometric characterization of the cutting edges of the tools using microscopy, while the indirect method utilizes the analysis of mechanical vibrations captured by sensors integrated into the CNC machine spindle. The methodology consists of the periodic collection of vibration signals throughout the tool lifespan, followed by analysis of the cutting edge condition through microscopic image analysis. The correlation between vibration levels and wear conditions observed in the microscopy analyses highlights the potential for using this information together to build a predictive model for estimating the optimal tool usage time, contributing to greater production efficiency.
Bioprospecção de rizobactérias com potencial de mitigação a Candidatus Liberibacter asiaticus e ao HLB
(Universidade Federal de São Carlos, 2026-07-06) Volponi, Alessia Zincone; Lima, Helena Santiago; http://lattes.cnpq.br/8307191971212434; https://orcid.org/0000-0001-6709-2745; Coletta Filho, Helvécio Della; http://lattes.cnpq.br/8783964270386788; https://orcid.org/0000-0002-1382-4629; http://lattes.cnpq.br/4583770492347988; https://orcid.org/0000-0002-1132-7127; Harakava, Ricardo; Magri, Marcia Maria Rosa; http://lattes.cnpq.br/1365069692823435; http://lattes.cnpq.br/4166319985147604; https://orcid.org/0000-0003-1431-2665; https://orcid.org/0000-0003-3541-1240
Among the major citrus diseases currently occurring in the state of São Paulo, Brazil, Huanglongbing (HLB), caused by the bacterium Candidatus Liberibacter asiaticus (CLas), is considered the most damaging to citrus production. To date, CLas has not been successfully cultured under axenic conditions outside its hosts (plants and Diaphorina citri), which has greatly hindered research on this pathogen. Genetically related and culturable microorganisms, such as Sinorhizobium meliloti (Sme) and Liberibacter crescens, have been used as model organisms in vitro to identify antimicrobial compounds and microbial antagonists against CLas. However, efficient screening strategies require both rapid in vitro approaches and in situ methods capable of directly evaluating the behavior of potential antagonists against CLas. The objective of this study was to select and evaluate bacterial genera previously described as antagonistic to phytopathogens for their potential activity against CLas. For this purpose, we had as goals: i. Conduct in vitro antagonism assays using S. meliloti as a model organism. ii. Evaluate the selected isolates over CLas titer and the plant physiological development in infected plants under greenhouse conditions. A total of 274 bacterial isolates were screened, of which 18 exhibited inhibitory activity, belonging to the genera Bacillus, Burkholderia, Lelliottia, Methylobacterium, Serratia, and Pseudomonas. Selected isolates were subsequently evaluated in CLas-infected citrus plants. Pathogen quantification was performed by qPCR in leaves and roots, together with assessments of plant growth characteristics. The results demonstrated that several isolates significantly reduced CLas titers during the experimental period. Among them, Methylobacterium_IAC80 was the most promising, reducing bacterial populations in both leaves and roots while also promoting plant growth. The isolates Serratia_IAC568, Lelliottia_IAC75, Pseudomonas_IAC532, and Bacillus_IAC362 also showed potential to reduce CLas populations in leaves, exhibiting performance equal or superior to oxytetracycline without causing negative effects on plant development.
Áudio imersivo: da estereofonia ao ambisonics
(Universidade Federal de São Carlos, 2026-07-14) Nobre, Gabriel; Nespoli, Eduardo; http://lattes.cnpq.br/0482744763085170; https://orcid.org/0000-0001-8613-1949; http://lattes.cnpq.br/4993285857361743; https://orcid.org/0009-0000-2130-8977
This undergraduate thesis investigates immersive audio recording and sound diffusion techniques through the study of Ambisonics technology. The research aims to understand the evolution of sound capture, processing, and reproduction technologies. Since the beginning of phonographic recording, the pursuit of expanding human auditory perception within physical space has driven audio engineering toward the research and development of systems more complex than those associated with monophonic and stereophonic sound diffusion. Currently, this trajectory is manifested in immersive sound diffusion, also referred to as three-dimensional (3D) audio. Technologies based on the Ambisonics protocol propose a fundamental shift: rather than encoding signals directly for specific loudspeakers, the sound field is represented through spatial axes, taking into account mathematical models associated with a three-dimensional spherical space. The results of this research indicate that Ambisonics technology fundamentally differs from traditional multichannel systems because it is based on the vector-based encoding of coordinates within a virtual spherical field, rather than on the distribution of sound energy among fixed loudspeakers. This characteristic enables its application in areas such as cinema, virtual reality gaming, electroacoustic music, and contemporary composition.
A formação continuada de professoras de bebês: profissionalidade e práticas pedagógicas na creche
(Universidade Federal de São Carlos, 2026-08-13) Vidal, Tassia Damião; Tomazzetti, Cleonice Maria; http://lattes.cnpq.br/4821077407620769; https://orcid.org/0000-0002-1976-4604; http://lattes.cnpq.br/2888603345818404; Onofre , Marcia Regina; Albuquerque, Simone Santos de; http://lattes.cnpq.br/7176529351192598; http://lattes.cnpq.br/3982004408663917; https://orcid.org/0000-0002-5467-185X; https://orcid.org/0000-0002-1111-464X
Continuing professional development for teachers working with infants in Early Childhood Education, although contemplated within educational policies, still faces challenges related to recognizing the specificities of teaching infants aged four to eighteen months. In this context, this study aimed to understand how the absence of specific continuing professional development for teachers working with infants influences the visibility and appreciation of their pedagogical practices in a municipal school system located in the countryside of São Paulo State, Brazil, as well as to support the development of a continuing professional development proposal tailored to the needs identified by these teachers. The study was grounded in research on teacher education, professional development, teacher professionalism, and teaching with infants, articulated with contemporary perspectives in Early Childhood Education. This qualitative study was conducted within the framework of a Professional Master's Degree in Education and combined documentary analysis of municipal continuing professional development policies implemented between 2015 and 2024 with empirical data collected through a questionnaire administered to teachers working with infants in the municipal school system. The data were analyzed according to the study's theoretical and methodological assumptions, aiming to identify convergences, tensions, and challenges related to continuing professional development and teaching with infants. The findings showed that the participating teachers have initial training consistent with their professional roles and develop intentional pedagogical practices, recognizing infants as active subjects and understanding experiences of care, interaction, welcoming, and play as essential components of the educational process. The analysis also revealed that the knowledge required for teaching infants is predominantly constructed through everyday experiences and peer interactions in a context characterized by the limited availability of professional development initiatives specifically designed for this field. The articulation between the documentary analysis of municipal policies and the empirical data collected from teachers demonstrated that, although continuing professional development initiatives exist, they do not always address the specificities of teaching infants or the professional learning needs of teachers. Although teachers mobilize relevant knowledge in their professional practice, the lack of systematic continuing professional development affects the consolidation, theoretical grounding, and legitimation of this knowledge, contributing to the persistence of the invisibility of pedagogical practices often associated primarily with physical care and reducing the recognition of their educational dimension. The results indicate that this invisibility does not stem from a lack of pedagogical intentionality or professional knowledge on the part of teachers, but rather from the insufficiency of professional development processes capable of recognizing, strengthening, and making visible the knowledge produced in the daily life of childcare centers, thereby affecting the visibility and appreciation of this field of practice. As an outcome of the study, an Educational Product entitled Knowledge and Practices Handbook: Dialogues on Teaching with Infants was developed, consisting of an interactive pedagogical handbook and a series of professional development meetings aimed at promoting reflection on practice, the systematization of teachers' knowledge, and professional growth. It is concluded that valuing teaching with infants requires continuing professional development policies that recognize the specificities of this field, strengthen the knowledge produced by teachers, and contribute to the visibility of pedagogical practices developed in childcare centers, reaffirming both the role of Early Childhood Education as the first stage of Basic Education and infants' right to high-quality educational experiences.