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.

Para mais informações, acesse: RI UFSCar

Instruções aos autores: Clique aqui.

Comunidades

Selecione uma comunidade para navegar por suas coleções

Agora exibindo 1 - 5 de 6

Submissões Recentes

Controle populacional de Diaphorina citri Kuwayama (Hemiptera: psyllidae) por aplicações sucessivas de inseticidas químicos e biológicos
(Universidade Federal de São Carlos, 2026-06-24) Torricelli, Guilherme Boteon; Martinelli , Rodrigo; Conceição, Patrícia Marluci da; http://lattes.cnpq.br/6623193710607120
Huanglongbing (HLB) is considered the most important disease affecting the citrus industry worldwide, and its spread is associated with the Asian citrus psyllid, Diaphorina citri Kuwayama. Due to the absence of resistant commercial cultivars, one of the main strategies for HLB management is the control of its insect vector, which is predominantly achieved through applications of chemical insecticides. However, control failures have been reported in citrus orchards and may be associated with the use of insecticides with a limited ability to interfere with the different deve-lopmental stages of the pest. Therefore, this study aimed to evaluate the efficacy of chemical insecticides with different modes of action and biological insecticides in the management of D. citri following sequential applications. The experiment was condu-cted under controlled conditions at the Sylvio Moreira Citrus Research Center of the Agronomic Institute of Campinas (IAC), using a completely randomized design with 10 treatments and four replicates. The treatments consisted of applications of bi-fenthrin, imidacloprid, malathion, buprofezin, pyriproxyfen, formetanate hydrochlori-de, cyantraniliprole, Cordyceps fumosorosea, Beauveria bassiana, and an untreated control. Control efficacy against the D. citri population was assessed by considering nymphs, adults, and the total insect population. The results demonstrated that cyan-traniliprole, imidacloprid, bifenthrin, and malathion were effective in controlling nym-phs, adults, and the total population. Pyriproxyfen and buprofezin provided interme-diate control of nymphs but showed low efficacy against adults. The biological insecticides exhibited poor performance against all developmental stages evaluated, indi-cating that their use should be directed toward long-term management strategies. It was concluded that bifenthrin, cyantraniliprole, imidacloprid, and malathion were the most effective insecticides for the population control of D. citri, although cases of re-sistance to some of these insecticides have been reported. Insecticide selection should consider all stages of the insect life cycle, and the rotation of modes of action is essential to delay the evolution of resistance, while integration with biological con-trol contributes to the long-term sustainability of pest management.
Eficácia de herbicidas residuais aplicados sobre diferentes estágios de decomposição de mulch de braquiária (Urochloa ruziziensis) em diferentes lâminas de precipitação
(Universidade Federal de São Carlos, 2026-06-24) Malagutti, João Farsoni; Martinelli, Rodrigo; Conceição, Patrícia Marluci da; http://lattes.cnpq.br/6623193710607120
The use of Urochloa ruziziensis mulch has proven to be an effective strategy for weed management in citrus orchards. However, its interaction with residual herbicides remains poorly understood. This study aimed to evaluate the efficacy of residual herbicides applied over U. ruziziensis mulch at different stages of decomposition under simulated rainfall amounts. The experiment was conducted in a greenhouse at the Sylvio Moreira Citrus Center (CCSM/IAC), Cordeirópolis, São Paulo, Brazil. A completely randomized design was used in a 3 × 2 factorial arrangement with five replications. The treatments consisted of three U. ruziziensis mulch conditions (no mulch, fresh mulch, and dry mulch) and two simulated rainfall amounts (5 and 20 mm). Independent experiments were conducted with the residual herbicides sulfentrazone, indaziflam, and oxyfluorfen, in addition to an untreated control. Common bean (Phaseolus vulgaris) was used as a bioindicator species and was sown before herbicide application. Seedling emergence was assessed at 7, 14, 21, and 28 days after application (DAA), and shoot dry biomass was determined at 28 DAA. The interaction between U. ruziziensis mulch and simulated rainfall influenced herbicide efficacy differently depending on the active ingredient. Sulfentrazone showed low weed control efficacy, with emergence inhibition ranging from 10 to 25% under all conditions, without significant differences among mulch treatments or rainfall amounts. Likewise, no significant differences were observed in shoot dry biomass reduction. The herbicide exhibited stable performance over time, likely due to its high water solubility and low sorption, which favor leaching. Indaziflam provided high weed control (approximately 80%), with greater efficacy under the 20-mm rainfall treatment, particularly in the presence of mulch. Shoot dry biomass reduction was also greater under the 20-mm rainfall treatment in the mulched treatments, whereas no differences were observed in the absence of mulch. Oxyfluorfen resulted in low to moderate emergence control (10–35%), with improved performance under the 20-mm rainfall treatment, especially when applied over fresh mulch. Similarly, shoot dry biomass reduction was significantly greater under 20 mm than under 5 mm of simulated rainfall. These findings highlight the importance of rainfall in activating residual herbicides and demonstrate that the interaction between mulch and the physicochemical properties of herbicides should be considered when developing weed management strategies in citrus orchards.
Framework multissensorial robusto para localização de robôs móveis em ambientes internos
(Universidade Federal de São Carlos, 2026-06-26) Martins Luna, Fernanda; Santos Inoue, Roberto; http://lattes.cnpq.br/6221209121565990; https://orcid.org/0000-0003-2813-9330; http://lattes.cnpq.br/7763885306832576; https://orcid.org/0009-0008-6632-176X; Wolf, Denis Fernando; Morandin Junior, Orides; Santos Inoue, Roberto; http://lattes.cnpq.br/8948846267711214; http://lattes.cnpq.br/4192845106907956; http://lattes.cnpq.br/6221209121565990; https://orcid.org/0000-0003-1485-5686; https://orcid.org/0000-0001-5588-100X; https://orcid.org/0000-0003-2813-9330
Autonomous mobile robots have been widely employed in indoor environments, such as warehouses, hospitals, laboratories, industrial facilities, and intralogistics systems. However, reliable localization of these systems remains a challenge, especially in scenarios without Global Positioning System signal availability and subject to odometric drift, repetitive geometries, inadequate lighting conditions, and uncertain sensory measurements. Although Simultaneous Localization and Mapping (SLAM) approaches based on the Extended Kalman Filter (EKF) are frequently used for sensor fusion, their performance may be degraded by modeling errors, local linearizations, and imperfect noise characterization. In view of these limitations, this dissertation proposes a robust multisensor framework to improve the localization of mobile robots in structured indoor environments. The approach integrates wheel odometry, observations of ArUco fiducial markers, and auxiliary pose estimates obtained from Adaptive Monte Carlo Localization (AMCL). The objective is to increase the accuracy, consistency, and robustness of pose estimation under real operating conditions, in which the nominal models of the system and sensors are subject to uncertainties. To this end, a formulation based on the Robust Kalman Filter (RKF), originally developed for discrete-time linear systems with norm-bounded parametric uncertainties, is adapted to a nonlinear EKF-SLAM structure with fiducial markers. The validation is carried out through real experiments and simulations, using a mobile robot equipped with 2D and 3D LiDAR-based sensors, an RGBD camera, and ArUco markers distributed in an indoor environment without GPS signal. The results are compared with BDUE-SLAM and conventional EKF-SLAM, considering trajectory estimation, drift reduction, and localization consistency. The results indicate that the incorporation of robust estimation strategies reduces the sensitivity of the system to model and measurement uncertainties, contributing to more reliable localization in structured indoor environments. Thus, this dissertation contributes a robust localization framework for autonomous mobile robots, preserving the recursive and computationally efficient structure of Kalman filters while extending their applicability to real-world indoor navigation scenarios.
Processamento ultrarrápido do eletrólito sólido Na₃Zr₂Si₂PO₁₂ pela técnica de reactive flash sintering
(Universidade Federal de São Carlos, 2026-07-28) Campos, Leonardo Jesus de; Jesus , Lilian Menezes de; http://lattes.cnpq.br/1731168664454710; https://orcid.org/0000-0002-6265-5542; Rodrigues, Ana Candida Martins; http://lattes.cnpq.br/4499231813051400; https://orcid.org/0000-0003-1689-796X; https://lattes.cnpq.br/1446190205368762; https://orcid.org/0009-0009-1227-1274; Almeida, Juliana Mara Pinto de; Bradtmüller, Henrik; http://lattes.cnpq.br/7830925338249360; http://lattes.cnpq.br/6765554058795910; https://orcid.org/0000-0003-4809-6278; https://orcid.org/0000-0001-7971-2163
Solid-state sodium batteries have attracted increasing interest due to the abundance and low production cost of sodium, as well as the potential for improved safety compared to batteries employing flammable liquid electrolytes. Among the most promising solid electrolytes is Na3Zr2Si2PO12 (NZSP), a member of the NaSICON family, which exhibits high ionic conductivity. However, its conventional processing requires calcination and sintering steps at high temperatures and long dwell times, promoting sodium and phosphorus volatilization and increasing energy consumption. In this work, Reactive Flash Sintering (RFS) was investigated as an alternative route to promote both NaSICON phase formation and densification of NZSP in a single processing step. The effects of the maximum applied power, dwell time, and power ramp rate on phase formation, microstructure, and electrical properties were systematically evaluated. The results demonstrated that the processing condition of 150 mW mm-3, combined with a power ramp rate of 30 mW mm-3 min-1 and a dwell time of 15 min, enabled the production of samples with a relative density of approximately 96%, a total ionic conductivity of 1.14 ± 0.11 mS cm-1, and an activation energy of 0.30 ± 0.01 eV. In comparison, conventionally processed samples exhibited lower conductivity (0.75 ± 0.02 mS cm-1) and higher activation energy (0.35 ± 0.01 eV). The use of sacrificial powder during conventional sintering, aiming to reduce the loss of volatiles, such as sodium or phosphorus, at high temperatures, increased the conductivity to values comparable to those obtained by RFS, indicating that the main advantage of the electric field-assisted process is associated with the reduction of volatile species losses during processing. The results demonstrate, for the first time, the feasibility of producing NZSP electrolytes by Reactive Flash Sintering directly from unreacted precursor powders, highlighting the potential of this technique as a rapid and energy-efficient route for the fabrication of solid electrolytes.
Covid-19, plataformas digitais e polarização política: uma cartografia sociotécnica-discursiva no Twitter/X a partir do segundo turno da eleição presidencial brasileira de 2022
(Universidade Federal de São Carlos, 2026-04-29) Martins, Marcelo de Seixas; Iasulaitis, Sylvia; http://lattes.cnpq.br/4226275371443693; https://orcid.org/0000-0002-3526-1003; http://lattes.cnpq.br/5714762989928041; https://orcid.org/0000-0002-9157-9550; Andrade, Thales Haddad Novaes de; Sousa, Cidoval Morais de; Silva, André Luiz da; Pimenta, Carlos Alberto Máximo; http://lattes.cnpq.br/5882842888759363; http://lattes.cnpq.br/0573233540937425; http://lattes.cnpq.br/1130631872986412; http://lattes.cnpq.br/6014753937589029; https://orcid.org/0000-0002-4000-3527; https://orcid.org/0000-0002-7812-8667; https://orcid.org/0000-0002-6974-0723; https://orcid.org/0000-0003-2815-7512
This thesis investigates the interconnections between Science, Technology, and Society (STS) through the analysis of the dynamics associated with the topic of Covid-19 vaccination in the Twitter/X environment, starting from the second round of the 2022 Brazilian presidential elections and its subsequent reconfiguration between 2024 and 2025. The research seeks to understand how the socio-technical configurations of the platform participate in the structuring and amplification of discursive disputes involving scientific themes in a context of polarization. The interdisciplinary approach mobilizes Actor-Network Theory (ANT) and Controversy Cartography (CC) as theoretical-methodological tools for mapping the socio-technical networks that comprise the investigated phenomenon through the adaptation of Oligoptic Maps (OM) to the digital environment. Empirically, this work articulates the exploration of The Interfaces Twitter Elections Dataset (ITED-Br), the third largest dataset of tweets with political purposes in the literature, with an ethnographic approach based on the analysis of hashtags, tweets, and user profiles. The results show that scientific themes are incorporated into broader symbolic disputes, marked by dynamics of polarization and deeply influenced by the platform's sociotechnical configurations. The thesis contributes to the advancement of STS studies by offering tools for understanding the relationships between digital platforms, scientific discourses, democracy, and contemporary socio-political dynamics.