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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PVA Films with Carbonized Kraft Lignin: Physico-Chemical Properties and Application in Gas Detection
(Universidade Federal de São Carlos, 2025-11-05) Fré, Lucas; Freitas, Amanda S. M.; Rodrigues, Jéssica S.; Simõis, André Vitor S.; Komatsu, Daniel; Oliveira, Vinicius Jessé R.; Olivati, Clarissa A.; Ferreira , Marystela; https://lattes.cnpq.br/1639776120503990; https://orcid.org/0000-0001-5133-2310; https://orcid.org/0000-0001-7074-4716; https://orcid.org/0000-0002-6023-6571; https://orcid.org/0000-0002-5750-1266; https://orcid.org/0000-0002-2441-8650; https://orcid.org/0000-0001-9234-3913; https://orcid.org/0000-0002-0114-6795; https://orcid.org/0000-0002-9459-8167
Kraft lignin (KL), a major byproduct of the pulp and paper industry, is still largely underutilized, limiting its value in advanced materials. This work investigates whether incorporating carbonized kraft lignin (CKL) into polyvinyl alcohol (PVA) films can enhance their structural and functional properties and enable their use as gas-sensor membranes. PVA films containing 0, 10, 30, and 50 weight percent (wt.%) CKL were prepared and characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), water-contact-angle (wettability) measurements, and tensile testing, followed by ammonia (NH3), ethanol (C2H5OH), and toluene (C7H8) sensing. CKL increased thermal stability (temperature at 5% mass loss, T5%, up to 135 °C vs. 80 °C for neat PVA), raised carbonaceous residue to 15%, and improved Young’s modulus while reducing elongation and water contact angle. Gas-sensing tests revealed a strong, reversible current response to NH3, with PVA/50 wt.% CKL exhibiting the highest current (ca. 23 µA), along with detectable responses to ethanol and toluene. These results demonstrate that CKL is an effective bio-derived additive that upgrades PVA films for sustainable, high-performance gas-sensing applications.
Déficit de natureza na infância e Educação Ambiental Crítica: reflexões sobre práticas e possibilidades na Educação Infantil
(Universidade Federal de São Carlos, 2025-12-10) Furtado, Marina Regina; Bravo, Daniela Gaete Sewaybricker; https://lattes.cnpq.br/0012269449134102; https://orcid.org/0000-0003-4047-1993; Torres, Juliana Rezende; http://lattes.cnpq.br/3083345943491817; https://orcid.org/0000-0002-4598-6702; http://lattes.cnpq.br/9520465398733763
Contemporary childhood experiences a growing detachment from the natural environment, a phenomenon conceptualized as "nature-deficit disorder" (Louv, 2018). Given this issue, the general objective of this study was to analyze how Environmental Education (EE) can help minimize this deficit in Early Childhood Education (ECE). To this end, a bibliographic research and documentary analysis with a qualitative approach were adopted. The investigation revealed that, although contact with nature brings holistic health benefits, current pedagogical practices of EE in ECE are predominantly conservative or pragmatic, focusing on decontextualized individual actions. It was found that these approaches are insufficient to address the structural causes of the problem. As the main result, the research identifies Critical Environmental Education (CEE) as the most appropriate pedagogical approach, as it goes beyond mere exposure to the environment and promotes the development of agency, critical consciousness, and a sense of socio-environmental justice. The study concludes by proposing a pedagogical flow that translates the principles of Critical-Transformative Environmental Education via Generative Theme (CTEE-GT) into the structural axes of ECE — interactions and play. This flow is organized starting from teaching intentionality, passing through interaction and reflection, and culminating in transformative action, demonstrating a viable path for the formation of critical subjects who belong to the world from early childhood.
As possibilidades de ação da terapia ocupacional em uma Instituição de Longa Permanência para idosos e suas reverberações formativas: um relato de experiência
(Universidade Federal de São Carlos, 2025-12-22) Araújo, Beatriz Financi; Oliveira, Marina Leandrini de; https://lattes.cnpq.br/4017135326666314; https://lattes.cnpq.br/4405738885572167
Introduction: Based on empirical data, population aging is a growing process and, beyond being a stage of life, it has become a relevant social issue that reveals a society that is socially, economically, and politically unprepared to support and guarantee the rights of older adults. In this context, Long-Term Care Institutions for Older Adults (LTCIs) play an important social role by providing shelter and care for the elderly population. However, for these institutions to effectively promote comprehensive care, a multidisciplinary team of professionals capable of addressing the intrinsic issues and specific needs of this population is required. Among these professionals, the occupational therapist stands out. Objective: This study aimed to report the experience of an occupational therapy student during an internship at an LTCI in a municipality in the interior of the state of São Paulo, Brazil, and to understand the possibilities of occupational therapy practice as a technical and scientific field of knowledge. Methodology: The methodological approach was based on an experience report derived from the observation of occupational therapy practice, as well as from institutional records and written notes produced by the intern over a four-month period. Results: The occupational therapy actions and their main objectives were described, establishing four analytical domains to technically systematize such practices: relationship, articulation, mediation, and professional training. Conclusion: It is concluded that the relational domain constitutes the foundation of all occupational therapy actions developed within the LTCI, demonstrating that the bonds established among the occupational therapist, older adults, staff, family members, and the community are essential for expanding support networks and positively transforming daily institutional life. Articulation, mediation, and professional training are also essential components for the development of new theoretical and methodological frameworks in occupational therapy as a field of knowledge. The practices carried out in the LTCI revealed the difficulty of technically describing occupational therapy actions, given that occupational therapy encompasses a wide range of possibilities and objectives. Finally, it is reaffirmed that aging is a universal process among living beings but is experienced in singular ways and trajectories. Therefore, promoting and ensuring healthy and dignified aging also requires a strong commitment to the education and training of future professionals.
Desenvolvimento de nanofibras de Pectina/HPC/PEO e Gelatina/HPC/PEO pela técnica de eletrofiação para liberação controlada de nitrogênio
(Universidade Federal de São Carlos, 2026-02-06) Gallo Godoi, Ian Raffaello; Ribeiro, Tatiana Santana; https://lattes.cnpq.br/7952918513827867; https://lattes.cnpq.br/6134659494518416; Pastre, Adriana de Campos; Souza, Adriano Lopes de; https://lattes.cnpq.br/2634621642907240; https://lattes.cnpq.br/4671885302437668
The excessive use of nitrogen fertilizers, such as urea, presents significant challenges, including contamination of water bodies and volatilization, which reduces its agronomic efficiency. In this context, the development of controlled-release systems emerges as a promising alternative to optimize nitrogen availability and minimize environmental losses. The present study aimed to develop and characterize polymeric nanofibers based on pectin/HPC/PEO and gelatin/HPC/PEO incorporated with urea, targeting their application in controlled nutrient release systems. The selection of pectin and gelatin as polymeric matrices was based on their potential for the development of sustainable systems, aligned with the principles of the circular economy, through the use of biodegradable compounds derived from industrial by-products. The nanofibers were produced by electrospinning, using optimized polymer solutions to ensure process stability and the formation of continuous fibers. Morphological characterization by scanning electron microscopy (SEM) revealed that the addition of urea enabled the formation of a well-defined network of continuous nanofibers with diameters on the nanometric scale, ranging from 225 nm to 1,039 nm for pectin fibers, and between 209 and 440 nm for gelatin fibers. FTIR and EDS analyses confirmed the incorporation of urea and the existence of chemical interactions between the fertilizer and the polymer matrices. Thermal stability was investigated by TGA and DTG, indicating that the addition of urea reduced the Tonset of the matrices by 2.2 °C for pectin and 3.3 °C for gelatin, evidencing a plasticizing effect. However, the incorporation raised the degradation temperature of the urea to levels above 200 °C, compared to 130 °C for free urea. Controlled release assays in aqueous medium, monitored by UV-Vis spectroscopy, demonstrated that the nanostructured systems promoted the gradual release of the nutrient. The pectin matrix showed a more pronounced initial release, reaching 68% in the first hours, while the gelatin fibers exhibited a more sustained profile, releasing 43% in the same period. Thus, the developed materials demonstrated potential for application as controlled-release fertilizer systems, contributing to a more efficient use of nutrients in agriculture.
Extração e caracterização dos óleos das pimentas Biquinho e da cultivar Maria Bonita: nanoencapsulamento com quitosana e ensaios de atividade antimicrobiana
(Universidade Federal de São Carlos, 2026-02-05) Dias, Aniele Beatriz; Ribeiro, Tatiana Santana; https://lattes.cnpq.br/7952918513827867; https://lattes.cnpq.br/5716975269887152; Torres, Juliana Arriel; Farias, Marco Antonio dos Santos; https://lattes.cnpq.br/8725209690219701; https://lattes.cnpq.br/2589951282251863
The growing environmental and sanitary concerns associated with the indiscriminate use of synthetic antimicrobials and sanitizers have driven the search for effective and sustainable natural alternatives for microbial control. In this context, this study aimed to extract, characterize, and nanoencapsulate oils from Biquinho and Maria Bonita peppers (Capsicum chinense), using chitosan as a polymeric matrix for the evaluation of antimicrobial activity.The selected microorganism, Limosilactobacillus fermentum, is a Gram-positive heterofermentative bacterium associated with fermentation processes and microbiological imbalances, potentially compromising product stability and quality by competing with desirable microorganisms. The oils were obtained by Soxhlet extraction using hexane and characterized by Fourier Transform Infrared Spectroscopy (FTIR), which revealed the presence of C–H bands from lipophilic groups, C=C bands from phenolic groups, and C=O bands from esters, as well as by Proton Nuclear Magnetic Resonance (^1H NMR), which confirmed the presence of capsaicin and dihydrocapsaicin. To enhance the stability of the active compounds, the oils were nanoencapsulated in chitosan obtained from shrimp waste through fermentative bioextraction followed by alkaline deacetylation, adding value to agro-industrial byproducts. The selection of chitosan is based on its biocompatibility, biodegradability, low toxicity, intrinsic antimicrobial activity, and its ability to form nanoparticles through ionic gelation. FTIR characterization confirmed the structural integrity of chitosan and the incorporation of the oils, evidenced by band shifts and reduction of C–H signals (3000–2800 cm⁻¹), indicating protection of lipophilic fractions. Field emission scanning electron microscopy (FEG-SEM) micrographs showed that pure chitosan exhibited an irregular and rough surface, whereas the encapsulated systems evolved into more spherical, homogeneous, and stable morphologies. Nanoparticles without oil showed an average diameter of 689 nm and a zeta potential of +32.40 mV, indicating colloidal stability. Oil incorporation promoted distinct structural changes: a 48.8% increase in diameter for the Biquinho oil system (1025.35 nm) and a 39.4% reduction for the Maria Bonita system (417.27 nm), highlighting different interactions with the polymeric matrix. Assays against Limosilactobacillus fermentum demonstrated high antimicrobial activity of the free oils (82.4% for Biquinho and 78.6% for Maria Bonita). After nanoencapsulation, modulation of activity was observed (54.3% and 49.8%, respectively). The results suggest that nanoencapsulation in chitosan not only protects bioactive compounds but also enables modulation of their biological action, expanding the possibilities for biotechnological applications, particularly in the development of natural and sustainable antimicrobial systems.