Navegando por Data de Publicação, começando com "2026-04-22"

Filtrar resultados por ano ou mês

Agora exibindo 1 - 5 de 5

Manejo de Megastigmus transvaalensis (Hymenoptera: Torymidae) e produtividade de Schinus terebinthifolia (Sapindales: Anacardiaceae) em área de restauração
(Universidade Federal de São Carlos, 2026-04-22) Massamba, Sandra Fazenete Picardo; Freato, Thiago Archangelo; https://lattes.cnpq.br/9898307927648033; Ferreira Filho, Pedro José; https://lattes.cnpq.br/3952696627229150; https://orcid.org/0000-0001-7132-6946; https://lattes.cnpq.br/5910244727234192; https://orcid.org/0000-0003-4911-6517; Thiersch, Cláudio Roberto; Cetra, Maurício; Guerreiro, Júlio César; Oliveira, Nádia Cristina de; https://lattes.cnpq.br/8791966697254106; https://lattes.cnpq.br/6775493342513120; https://lattes.cnpq.br/8751039433936733; https://lattes.cnpq.br/3317779428214532
Efficient, sustainable, and economically viable control methods are studied for monitoring forest pests, such as the exotic wasp Megastigmus transvaalensis Hussey, 1956 (Hymenoptera: Torymidae). This wasp damages the drupes of the Brazilian pepper tree Schinus terebinthifolia Raddi, 1820 (Sapindales: Anacardiaceae) in native forests, restoration areas, and commercial crops in Brazil. Given the economic value of S. terebinthifolia and its applications in food seasoning, traditional medicine, cosmetics, bioactive compounds, the pharmaceutical industry, biopesticides, flavoring, and the recovery of degraded areas, there is a need to protect its drupes from M. transvaalensis attacks in the field. This study aimed to: i) use a physical barrier to prevent M. transvaalensis attacks and determine the parasitism rate in S. terebinthifolia drupes; ii) evaluate the drying kinetics of the drupes in the laboratory; and iii) estimate the plant's productivity in the field. Five fragments of seasonal semideciduous forest undergoing ecological restoration, with sixteen randomly selected S. terebinthifolia plants, were used. A physical barrier made of non-woven fabric (TNT) (25 cm long x 21 cm wide) was used as a treatment and applied for approximately 120 days. In the drying study, mature drupes were subjected to different temperatures (30°C and 105°C), with moisture content and mass reduction data fitted to exponential and hyperbolic models. For productivity estimation, data on diameter at breast height (DBH), total tree height (Ht), and crown area (Acrown) were collected from 16 individuals, applying Principal Component Analysis (PCA) to reduce dimensionality and predict yield. The parasitism rate was higher (60.45%) in the unprotected treatment and lower (8.06%) in the treatment protected with the fabric barrier, preserving the embryonic and epicarp integrity of the drupes. The hyperbolic model demonstrated statistical superiority, showing performance indicators for predicting both moisture content (R2Adj = 0,98; AIC = 196,52; RMSE = 0,55; X2red = 0,308) and mass reduction (R2Adj = 0,954, AIC = 254,50; RMSE = 0,706; X2red = 0,507), outperforming the exponential model. The drying kinetics showed a maximum initial rate of 0.7916% h-1 with a sharp reduction after 24h (0.1112% h-1); based on the asymptotic point (y = 1.9%), a period of 48 hours (0.0421% h-1) was established as ideal for dehydration. Finally, the productivity modeling integrated dendrometric variables and parasitism rates monitored throughout the field study, revealing that isolated variables such as DBH (p = 0.021) showed instability in the models due to multicollinearity. Thus, PCA was performed, with the first component (PC1, plant vigor) standing out as the most reliable predictor of productivity (R2Adj = 0.27; p = 0.0204), while the average parasitism rate by M. transvaalensis (P_Average) showed no significant direct linear influence on the studied sample (n = 16). In conclusion, the integration of physical exclusion methods and mathematical modeling establishes fundamental guidelines for post-harvest management and the reproducibility of forest restoration processes with S. terebinthifolia.
Entre a prescrição e a incorporação do tempo: o paradoxo do desempenho na formação de jovens engenheiros: Uma análise crítica das experiências de estudantes e egressos da Engenharia de Produção no processo formativo e profissional
(Universidade Federal de São Carlos, 2026-04-22) Silva, Mayra Resende Mendes de Oliveira; Saltorato, Patrícia; https://lattes.cnpq.br/4086015205835355; https://lattes.cnpq.br/1229697327422129; https://orcid.org/0009-0001-2073-0321; Fontes, Andréa Regina Martins; Martins, Thais Joi; https://lattes.cnpq.br/4848646681792317; https://lattes.cnpq.br/1495908295162360
The social organisation of time constitutes a central element in shaping modern work and in the production of performance-oriented subjectivities. In contemporary capitalism, the intensification of temporal rationality permeates not only productive spaces, but also formative processes, particularly in technical-scientific fields such as Production Engineering. With this in mind, the present work aims to investigate how young students and graduates of the Production Engineering course at UFSCar experience the relationship between prescribed time and lived time throughout their formative and professional trajectories. The research is relevant insofar as it analyses time as a historical, technical, and moral construction within a field marked by rationality and metrification. The theoretical framework draws upon studies in the social history of time, sociology of work, critical theory of capitalism, and the psychodynamics of work. A qualitative approach was adopted, combining prosopographic analysis with a Bourdieusian reading of trajectories, based on thirty semi-structured interviews with agents who are socially situated within the field of study. The findings indicate that the internalisation of time as a moral principle of performance generates paradoxes and tensions, which are further reinforced by the formative process. The prescription of time is gradually transmuted into the incorporation of time, becoming an integral part of the young engineer's habitus. It is concluded that training in Production Engineering may be configuring itself as a structuring and structured instrument of temporal formation, aimed at producing an accomplished manager of systems who, paradoxically, tends to remain a prisoner of the very time he himself helps to accelerate.
Relação entre estrutura e atividade catalítica do cobre na hidrogenação do CO2 para formação do metanol
(Universidade Federal de São Carlos, 2026-04-22) Simionato, Arnaldo Agostinho; Santos, João Batista Oliveira dos; https://lattes.cnpq.br/0285313473901330; https://lattes.cnpq.br/2322073284273845; Moreira, Regina de Fátima Peralta Muniz; Oliveira, Jéssica Ariane de; https://lattes.cnpq.br/8521588947381085; https://lattes.cnpq.br/4765767150921439
In the context of the commitments made under the Paris Agreement to reduce greenhouse gas emissions and limit the global temperature increase to 1.5 °C above pre-industrial levels by mid-century, there is a clear need to transition current energy systems and to develop effective technologies for carbon dioxide (CO2) utilization. Among the strategies under investigation, the hydrogenation of CO2 to methanol has attracted considerable attention, both as a means of mitigating atmospheric CO2 and as a route to convert it into value-added chemicals. Methanol is a key commodity in the chemical industry, with global production exceeding 90 million tons in 2025. It is widely used as a solvent and as a feedstock for the synthesis of numerous chemical products. A variety of catalysts have been explored for methanol synthesis via CO2 hydrogenation, with copper-based systems consistently showing the most promising performance, particularly in terms of cost-effectiveness and activity. However, the relationship between catalyst structure and activity remains a matter of ongoing debate. In this work, the effect of Cu particle size on methanol synthesis was investigated. Cu/Zr-SBA-15 catalysts were prepared by the impregnation method and characterized using X-ray diffraction, nitrogen physisorption, H₂ temperature-programmed reduction, N2O decomposition and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). These analyses confirmed the successful preparation of catalysts with a range of particle sizes, with estimated diameters between 4.1 and 35.3 nm. Catalytic testing showed that CO2 hydrogenation to methanol follows behavior consistent with a class π reaction, although only minor variations were observed across the samples. Mechanistic insights obtained from ME-PSD-DRIFTS (Modulation-Excitation Phase Sensitive Detection Diffuse Reflectance Fourier Transform Spectroscopy) suggest that either the hydrogenation of methoxy species or the desorption of methanol is the slow step in the reaction. Apparent activation energy measurements indicated values below 44 kJ/mol for all catalysts in methanol formation. Taken together, these results suggest that methanol desorption is the rate-limiting step, possibly due to its interaction with oxophilic sites associated with zirconium.
“Novos complexos quadráticos planos contendo tiossemicarbazonas derivadas de salicilaldeído: investigação da atividade antitumoral em modelos celulares 2D e 3D”.
(Universidade Federal de São Carlos, 2026-04-22) Teixeira, Tamara; Rocha, Fillipe Vieira; http://lattes.cnpq.br/5841127259122766; http://lattes.cnpq.br/6134388681686521; https://orcid.org/0000-0003-3227-9395; Moura, Aniele; Teixeira , Felipe Roberti; Scarim, Cauê Benito; Netto, Adelino Vieira de Godoy; http://lattes.cnpq.br/5260272000100355; http://lattes.cnpq.br/3568850159381693; http://lattes.cnpq.br/6436745574756887; http://lattes.cnpq.br/7927677053650819; https://orcid.org/0000-0002-3475-6207; https://orcid.org/0000-0003-0251-2686; https://orcid.org/0000-0002-2540-6395; https://orcid.org/0000-0002-0057-7964
Cancer remains one of the leading causes of mortality worldwide, highlighting the need for the development of more selective and effective therapeutic agents. In this context, metal complexes containing thiosemicarbazones have attracted considerable interest due to their structural versatility and their potential to modulate relevant biological properties. The present study aimed to synthesize, structurally characterize, and evaluate the antitumor activity of new Pd(II), Pt(II), and Ni(II) complexes containing salicylaldehyde-derived thiosemicarbazones associated with triphenylphosphine. Characterization of the compounds by molar conductivity, infrared and UV–Vis spectroscopy, mass spectrometry, nuclear magnetic resonance, and single-crystal X-ray diffraction confirmed the formation of neutral complexes with distorted square-planar geometry, in which the thiosemicarbazones act as tridentate (O,N,S) ligands. The complexes exhibited high stability in solution, consistent with multidentate coordination and the structural rigidity of the system. Cell viability assays revealed that cytotoxic activity was restricted to complexes containing the D2 ligand, bearing two nitro groups, in ovarian cancer cell lines, with particular emphasis on the Pd(II) complex, which showed the highest activity. Morphological and clonogenic assays demonstrated that the PdD2 complex exerts both cytotoxic and cytostatic effects, in addition to displaying greater selectivity toward tumor cells. Mechanistic studies, employing fluorescent probes and flow cytometry, indicated that the compound induces cell death predominantly through apoptosis, associated with alterations in the cell cycle, loss of membrane integrity, and depolarization of the mitochondrial membrane potential. Furthermore, experiments in three-dimensional models demonstrated that the PdD2 complex retains its activity in more physiologically relevant microenvironments, affecting the morphology, growth, and viability of tumor spheroids. Taken together, these results position the PdD2 complex as a promising candidate for the development of new thiosemicarbazone-based antitumor agents.
Revisão sistemática da literatura de modelos de otimização para o planejamento de redes de logística reversa de resíduos eletroeletrônicos
(Universidade Federal de São Carlos, 2026-04-22) Ballerini, Lizete de Paula; Toso, Eli Angela Vitor; https://lattes.cnpq.br/6663631731115739; https://orcid.org/0000-0001-7531-0300; https://lattes.cnpq.br/1813756661264536; https://orcid.org/0000-0002-0728-5470; Silva, João Eduardo Azevedo Ramos da; Santos, Maristela Oliveira dos; https://lattes.cnpq.br/3823047207711289; https://lattes.cnpq.br/0756373063566786; https://orcid.org/0000-0002-6739-5065; https://orcid.org/0000-0003-0822-3439
Global waste generation is rapidly increasing; in response, industries and policymakers are prioritizing circular economy initiatives and waste recycling to reduce environmental impact and operational costs. Waste Electrical and Electronic Equipment (WEEE) is among the fastest-growing waste streams, and while it contains hazardous materials, it also offers opportunities for resource recovery. However, managing WEEE is complex due to the high capillarity of collection points and the challenges of transport logistics. The literature on optimization models for reverse network planning problems and decision support systems can help solve these problems, improving efficiency and environmental performance in Reverse Logistics and Closed Loop structures. This dissertation examines optimization models for Reverse Logistics network planning, analyzing how social, environmental, and economic factors are considered in decision-making, such as facility location, transportation, inventory management, and network design. The findings reveal that in WEEE Reverse Logistics, only 38% apply the closed-loop system, reflecting its logistical and technological complexities. Cost minimization remains the dominant objective in 19% of the models, but 60% integrate environmental considerations and 19% adopt a Triple Bottom Line approach, incorporating economic, environmental, and social dimensions. Despite transportation being a critical factor in reverse logistics planning, 22% of the models address the selection of transportation modes. These findings highlight the need for optimization approaches that integrate multi-objective decision-making and sustainability-oriented frameworks. By addressing these gaps, this research contributes to strengthening WEEE Reverse Logistics, providing support for the construction of more efficient, economically viable, and environmentally sustainable systems.