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Sistema Iot lorawan open-source para monitoramento e gestão hídrica: implementação e validação em Campus Universitário
(Universidade Federal de Lavras, 2025-12-18) Paviani, João Antonio Resende; Correia, Luiz Henrique Andrade; Salgado, André de Lima; Moraes, Hermes Pimenta d; Macedo, Daniel Fernandes
This dissertation demonstrates the technical and managerial feasibility of an open end-to-end system for intelligent monitoring of water consumption on a university campus. The architecture integrates SAGATECH US-5.0 smart meters, a LoRaWAN network with a Browan gateway, the ChirpStack (v4) network server, a Python–MySQL pipeline, and Grafana visualization. The system was deployed at 182 points and operated in the operational dataset (22/09/2024–22/09/2025), producing auditable time series. Data quality was quantified along three dimensions: weighted global completeness of 78.54% (per-device median of 83.68%; Q1–Q3: 78.55–89.01%; 22.9% of points with completeness ≥ 90%); interval regularity with a median of 60.0 min and 89.9% of records within the 45–75 min corridor; and internal consistency with 0.00% negative increments and a median of zero reset events, together with P50 = 0.00L, P90 = 84.00L, and P99 = 631.00L for hourly increments. Accuracy was validated on the Dval dataset (28/04/2025–12/06/2025; 11 points) through interval-based AMI–AMM comparison without interpolation, using the timestamps closest to [t0,t1]; relative errors ranged from −0.434% to +0.459%, remaining within the ±2% limit specified by the applicable metrological regulation. As a practical deliverable, a reproducible operational triage was implemented to prioritize maintenance, based on communication silence and atypical night-time consumption (threshold defined by a high percentile of the dataset itself). The solution, in addition to being scalable and low cost, provides data quality suitable for managerial use and accuracy consistent with manual reference measurements, offering a solid basis for institutional expansion and replication.
Fibrocimento com resíduos lignocelulósicos encapsulado com copolímero etileno acetato de vinila (EVA)
(Universidade Federal de Lavras, 2025-09-12) Nunes, Glauco Fernandes de Oliveira; Mendes, Lourival Marin; Guimarães Junior, José Benedito; Mendes, Lourival Marin; Guimarães Junior, José Benedito; Batista, Felipe Gomes
The study investigated the development of fiber,reinforced cement composites produced by extrusion, reinforced with lignocellulosic residues from the species Erythrina poeppigiana (cellulose particles and nanofibrils) and incorporating pulping residues (dregs), with subsequent encapsulation by ethylene,vinyl acetate copolymer (EVA). The objective was to evaluate the physical, mechanical, and microstructural performance of these composites, aiming to increase their durability against weathering and the alkalinity of the cementitious matrix. Properties such as bulk density, porosity, water absorption, modulus of rupture, modulus of elasticity, proportional limit, toughness, and microstructure were analyzed using scanning electron microscopy. The results showed that encapsulation with EVA reduced water absorption by up to 36%, maintained porosity below 28%, and favored the cohesion of the matrix,reinforcement interface. The composite containing nanofibrils and dregs stood out, presenting a modulus of rupture of 8.7 MPa, a modulus of elasticity greater than 4.9 GPa, and an average toughness of 1.08 kJ/m². It is concluded that the use of lignocellulosic waste from Erythrina poeppigiana, associated with encapsulation with EVA, represents a promising strategy for the production of sustainable cementitious materials, contributing to the valorization of residual biomass and to the principles of the circular economy.
Efeito da conversão de campos nativos por pastagens exóticas e o uso de ivermectina na relação entre ácaros Macrochelidae (Acari: Mesostigmata) e Dichotomius bos (Coleoptera: Scarabaeidae)
(Universidade Federal de Lavras, 2024-09-27) Lyra, Raphael Rodrigues; Louzada, Júlio Neil Cassa; Passamani, Marcelo; Correa, César Murilo de Albuquerque
The Cerrado biome harbors high biodiversity and plays a fundamental role in maintaining ecological processes and providing ecosystem services. However, the conversion of natural areas into agro-pastoral systems and the adoption of intensive management practices have promoted significant changes in the structure and functioning of these environments, particularly affecting edaphic biota and soil-associated ecological interactions. Among the organisms potentially impacted by these changes are dung beetles of the subfamily Scarabaeinae and phoretic mites of the family Macrochelidae, functionally interdependent groups that are important for the dynamics of bovine dung. This dissertation aimed to evaluate the effects of the conversion of native pastures into exotic pastures and the use of ivermectin in livestock management on population metrics and phoretic relationships between the dung beetle Dichotomius bos (Coleoptera: Scarabaeidae) and associated Macrochelidae mites in cattle ranching areas in the region of Carrancas, Minas Gerais, Brazil. To this end, beetles were collected in areas with different pasture types and histories of ivermectin use, followed by the quantification and identification of phoretic mites associated with the sampled individuals. A total of 8,776 mites associated with 288 individuals of Dichotomius bos were collected, belonging to eight Macrochelidae species. The results indicated that ivermectin use was associated with a reduction in the abundance of the phoretic mite community, whereas the conversion of native pastures into exotic pastures did not result in significant differences in the evaluated metrics. Species richness remained constant among the different management types, possibly due to the approach focusing on a single host species. Overall, the results demonstrate that livestock management practices can influence the structure of edaphic communities and the ecological interactions associated with bovine dung. Thus, this study contributes to a better understanding of the effects of anthropization on Cerrado edaphic biodiversity and reinforces the importance of considering interspecific interactions in ecological assessments of pastoral systems.
Bacillus amyloliquefaciens CN 307 e sua formulação comercial na quimiotaxia de Meloidogyne incognita
(Universidade Federal de Lavras, 2025-12-12) Caetano, Pâmella de Sá; Terra, Willian César; Cavalcanti, Vytória Piscitelli; Alves, Eduardo; Siqueira, Carolina da Silva; Teixeira, Lívia Pimenta
The root-knot nematode, Meloidogyne incognita, causes significant damage to agriculture worldwide. Experiments were conducted in a greenhouse and at the Nematology Laboratory of the Federal University of Lavras, Minas Gerais, Brazil. Treatments consisted of applying the commercial product Auba® or the isolate B. amyloliquefaciens CN 307 to seeds of soybean (Glycine max L.), cv. M 6410 IPRO, common bean (Phaseolus vulgaris L.), cv. 2051, and corn (Zea mays L.), hybrid P 3707VYH C1. Chemotaxis assays showed that treated root exudates and roots exhibited a repellent effect on J2 nematodes, a result also observed when only the product or the isolate was tested. Biofilm formation occurred only in bean roots treated with the product. In beans, the commercial product and the isolate reduced the number of galls per gram of root by 31.24% and 42.96%, respectively, and the number of eggs per gram of root by 55.32% and 40%. In the second experiment, there was no significant reduction in the number of galls, but there were reductions in the number of eggs per gram of root of 59.78% with the product and 32.14% with the isolate. In soybeans, in the first experiment, there was no significant reduction in the number of galls per gram of root; however, the number of eggs was reduced by 64.18% with the product and 38.31% with the isolate. In the second experiment, the reductions in the number of galls per gram of root were 38.33% with the product and 27.80% with the isolate, with no significant effect on the number of eggs. Microscopic analysis with Raman spectroscopy indicated, in the treated roots, peaks associated with cellulose, xylan, and lignin, with a predominance of cellulose in beans and lignin in soybeans. The results indicate that the product and the isolate have potential for the biological management of M. incognita, acting through direct effects and biochemical alterations in root tissues.
Modelos de regressão para dados de áreas com valores extremos no estudo da incidência de dengue em Minas Gerais
(Universidade Federal de Lavras, 2025-09-30) Damaceno, Gean Pereira.; Scalon, João Domingos; Silva, Douglas Mateus da; Lima, Renato Ribeiro de; Manzato, Lourenço; Oliveira, Deive Círio de
Dengue fever has become a growing threat in recent years, with frequent outbreaks and overwhelming healthcare systems. The spread of the virus, transmitted by Aedes aegypti, is strongly related to environmental and urban factors, making the use of statistical methods essential to understand its dissemination and implement more effective actions to combat it. Traditional linear regression models, although widely used, assume the independence of observations and do not consider spatial autocorrelation, which, when present, can compromise the accuracy of estimates in geographically interdependent areas. To overcome this limitation, spatial models such as Simultaneous Autoregressive Regression (SAR) and Conditional Autoregressive Regression (CAR) have emerged as solutions. These models are able to capture spatial patterns that are normally present in area data. However, these models are sensitive to outliers, which generally impair the quality of the analyses. Geographically Weighted Regression (GWR), which incorporates spatial variation through local estimation of coefficients, has been proposed as an alternative but can also be influenced by outliers. Robust Geographically Weighted Regression (RGWR) has been proposed as an improved solution that can provide greater robustness against outliers and, consequently, lead to more effective estimates. This study applies RGWR to investigate the incidence of dengue fever in the state of Minas Gerais, in the year of 2023, aiming to improve the accuracy of estimates in the face of outliers, which are very common in this type of data. The variables used in the study were: dengue fever incidence as the dependent variable and adequate sanitation, urbanized area, street urbanization, and street tree planting as independent variables. The results showed that RGWR can provide a more accurate approach to understanding the spatial distribution of dengue in data from areas with outliers which can contribute to more efficient and effective management of public health actions.