Principais Coleções do Repositório
Submissões Recentes
Lousa digital na alfabetização: a aprendizagem da leitura e escrita mediada por recurso multimidiático
(Universidade Federal de Lavras, 2025-04-25) Maranha, Angélica Souza; Goulart, Ilsa do Carmo Vieira; Glória, Juliana Silva; Cabral, Giovanna Rodrigues; Goulart, Ilsa do Carmo Vieira
This work focuses on discussions about digital technologies in the school context, specifically in relation to the use of the digital whiteboard in literacy, emphasizing practices regarding reading and writing mediated by a multimedia resource. Therefore, this research has the general objective of identifying the pedagogical practices developed with the digital whiteboard in the literacy process by teaching professionals, with the aim of understanding how such pedagogical proposals can help in learning to read and write. The specific objective of this study is to determine what changes occur in teaching practices with the introduction of digital technologies; to identify the shifts in teaching practices from the blackboard to the digital whiteboard; and how these shifts are most beneficial and conducive to broader, more concrete school development. To this end, a qualitative field study was conducted, based on the monitoring of reading and writing activities carried out using the digital whiteboard in literacy classes. To support the theoretical discussions, support was sought from Soares's (2018) studies on literacy; Coscarelli and Ribeiro's (2011) studies on digital literacy and Rojo's (2012) studies on multiliteracies; and Nóvoa's (2006) studies on teacher training. The results of this study emphasize the use of the digital whiteboard in literacy instruction and in the development of reading and writing in classroom pedagogical practices, guiding teachers on the appropriate use of this multimedia resource. Thus, as an educational product, resulting from this research, a workshop was developed for literacy teachers who teach in the 1st and 2nd years of elementary school (initial years), with an emphasis on multimedia reading and writing resources.
Gestão de riscos em pilhas de rejeitos: aplicação do padrão global da indústria para gestão de rejeitos e proposição de um índice global de riscos
(Universidade Federal de Lavras, 2025-07-09) Alberto Junior, Carlos; Cândido, Eduardo Souza; Menezes, Danielle Aparecida de; Ribeiro, André Geraldo Cornélio; Santos, Tatiana Barreto dos
The growing demand for safer and more sustainable tailings disposal solutions in mining has encouraged the adoption of dry-stacked tailings facilities (DSTFs), or dry disposal piles (PDRs), as alternatives to conventional tailings dams. In this context, the Global Industry Standard on Tailings Management (GISTM), launched in 2020, has become an international reference for risk management in tailings storage facilities. However, its application to PDRs still lacks specific interpretations that consider the unique characteristics of these structures. This dissertation, presented in article format, aims to assess the applicability of the GISTM to PDRs and to propose a risk analysis methodology based on a Global Risk Index (αg) that integrates structural, environmental, legal, reputational, financial, and psychosocial dimensions. The first article analyzes data from five PDRs using the Risk Control Management System (RCMS) methodology, identifying how GISTM requirements are distributed across different risk categories whose risks are most frequent. The second article proposes a semi-quantitative risk assessment tool grounded in GISTM requirements, applied to the same structures, allowing the classification of risk zones and the prioritization of mitigation actions. The results show that the GISTM functions as an effective risk control tool, although it presents specific limitations when applied to PDRs. The proposed αg index proved to be a robust alternative to support risk governance and enhance decision-making in mining operations, contributing to improved safety, regulatory compliance, and sustainability in the sector.
Determinação do perfil farmacocinético de ciprofloxacina administrada por via intramuscular em bezerras Holandesas
(Universidade Federal de Lavras, 2025-07-10) Mongelli Sanches, Melissa; Brandão, Humberto de Mello; Ferrante, Marcos; Tomas, Hugo Shisei; Lima, Ana Milena Cézar
Ciprofloxacin is a fluoroquinolone approved by the Brazilian Ministry of Agriculture, Livestock, and Food Supply (MAPA) for the treatment of respiratory, urinary, enteric, cutaneous infections, and mastitis in cattle. Although enrofloxacin is the most commonly used drug in ruminants, ciprofloxacin—its active metabolite—shows high antimicrobial activity against relevant pathogens such as Escherichia coli, Salmonella spp., Mannheimia haemolytica, Pasteurella multocida, and Mycoplasma spp. This study aimed to characterize the pharmacokinetic profile of ciprofloxacin following intramuscular administration in Holstein heifers and to evaluate the efficacy of different dosing regimens by integrating pharmacokinetic and pharmacodynamic (PK/PD) parameters. Twelve healthy animals were used, each receiving a single intramuscular dose of 2.5 mg/kg of ciprofloxacin. Plasma concentrations were quantified by ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). Population pharmacokinetic modeling was performed using a one-compartment model with first-order absorption and linear elimination, estimating the following parameters: Ka (17.49 h−1), volume of distribution (257.8 L/kg), and clearance (51.38 L/kg/h), with high interindividual variability observed. Monte Carlo simulations were conducted for doses of 2.5, 5, 7.5, and 10 mg/kg, considering a range of minimum inhibitory concentrations (MIC) between 0.03 and 2 μg/mL, and incorporating the interindividual variability of the estimated pharmacokinetic parameters to assess the probability of target attainment (PTA) based on PK/PD indices established for fluoroquinolones (Cmax/MIC ≥ 10 and fAUC/MIC ≥ 125). The results indicate that the 2.5 mg/kg dose provides high PTA for microorganisms with MIC below 0.125 μg/mL, while higher doses are required to ensure efficacy against pathogens with higher MICs. This study provides fundamental data for optimizing ciprofloxacin therapeutic regimens in heifers, contributing to the rational use of antimicrobials and mitigation of bacterial resistance in veterinary practice.
Suplementação com n-carbamilglutamato em ruminantes: revisão sobre seu potencial na redução do estresse térmico e emissões de gases de efeito estufa
(Universidade Federal de Lavras, 2025-06-30) Marins, Amanda Stefany Ferreira; Batista, Erick Darlisson; Danés, Marina Arruda Camargos; Homem, Bruno Grossi Costa
This thesis reviews the effects of N-carbamylglutamate (NCG) supplementation in dairy cows subjected to heat stress, focusing on reducing heat stress, metabolic effects, and methane production. The research highlights the growing concern regarding climate change and greenhouse gas emissions, especially methane, whose origin in livestock activity is significant in Brazil. The study shows that heat stress, aggravated by global warming, compromises productive and physiological performance and animal welfare, influencing ruminal fermentation and methane emissions. NCG supplementation has demonstrated potential to improve metabolic efficiency, increase milk protein and fat production, reduce stress hormones, improve immunity, and positively alter ruminal microbiota and nutrient utilization. Despite promising evidence, further studies are still necessary to quantify the impact of NCG on reducing methane emissions during ruminal fermentation, thus contributing to more sustainable strategies in milk production in hot climate regions.
Látex de borracha natural como adesivo alternativo para painéis de partículas de média densidade
(Universidade Federal de Lavras, 2025-02-25) Mesquita, Karini de Lourdes Silva; Martins, Maria Alice; Guimarães Júnior, José Benedito Henrique; Lago, Rafael Carvalho; Batista, Felipe Gomes; Silva, Cínthia Aparecida da
Formaldehyde emissions from urea-formaldehyde (UF)-based adhesives, widely used in wood panel production, have raised significant environmental concerns. This study evaluated the use of centrifuged natural rubber latex (NRL) as a partial substitute for UF in the manufacture of medium-density particleboard (MDP), in four proportions: T0%, T20%, T40%, and T60%. Analyses included moisture content, chemical structure, gel time, pH, rheology, solids content, optical and electron microscopy (SEM), density, swelling, water absorption, bending strength (MOR), modulus of elasticity (MOE), screw withdrawal resistance, thermogravimetric analysis, thermal conductivity, and formaldehyde emissions. Pinus oocarpa particles contained 5.61% extractives, 31.36% lignin, 62.89% holocellulose, 31.53% cellulose, and 0.14% ash, with thermal stability up to 250 °C. The UF and NRL adhesives had solids contents of 75 ± 0.04% and 66.6 ± 1.18%, viscosities of 28.3 ± 1.1 cP and 490 ± 24 cP, gel times of 55 ± 2.4 s and 53.19 ± 1.61 s, and pH values of 8.15 ± 0.3 and 10.22 ± 0.61, respectively. Rheological analysis showed that NRL altered the behavior of UF, forming a non-Newtonian hybrid fluid with initial fluidity and rapid solidification. The average panel density was 0.56 g/cm3 (M-2 class), with compaction ratios ranging from 1.06 (T0%) to 1.10 (T20%). The addition of NRL increased water absorption and swelling, reaching 50.9% after 2 h (T60%) and 48.8% after 24 h. The T20% treatment met the requirements of the ABNT NBR 14810-2 (2013) standard for MOR and MOE, while T20% and T40% remained within the regulatory MOE limits. T20% also met the standard for screw withdrawal resistance (ABNT NBR 14810- 2:2018). Thermal conductivity was maintained across all treatments, with a slight reduction in T40%. SEM analysis of the NRL treatments showed poor interaction between components, with clump formation and irregular adhesion, negatively affecting physical and mechanical properties. Formaldehyde emissions progressively decreased with increasing NRL content; all treatments were classified as E1 (most restrictive), with T60% showing a 99% reduction in emissions. It is concluded that NRL can replace up to 20% of UF without compromising panel performance, and that higher proportions progressively reduce formaldehyde emissions, representing a more sustainable solution for the industry.