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Danos de instalação em geogrelhas de poliéster em agregado natural e fresado de revestimento asfáltico (RAP)
(Universidade Federal de São Carlos, 2025-05-09) Névoa, Fernando Affonso; Correia, Natália de Souza; https://lattes.cnpq.br/2172645507238077; https://orcid.org/0000-0002-6867-9596; https://lattes.cnpq.br/8852428101648227; https://orcid.org/0009-0005-2969-4784
Geogrids are frequently used as reinforcement elements in infrastructure projects and geotechnical structures, providing increased load-bearing capacity and reduced deformations. However, the reinforcement function of geogrids can be compromised by damage occurring during the field installation process. To ensure that the design strength of the reinforcement aligns with actual service conditions, these damages are accounted for in engineering designs through installation damage reduction factors (FRDI), which vary depending on the characteristics of the material comprising the backfill layer. However, there is a gap in understanding the reduction factors for geogrids when used with alternative materials, such as construction and demolition waste (RCD) or recycled asphalt pavement (RAP). In this context, this study aims to assess the mechanical damage caused by the installation of geogrids in compacted RAP aggregate layers, comparing them to conventional aggregates (sand) and analyzing the influence of the physical characteristics of RAP on the micro and macro damage observed in the reinforcement. To achieve this, experimental tests were conducted following the ASTM D5818-22 standard. The results indicate a significant loss of strength in the geogrids used with RAP, with installation damage reduction factors (FRDI) ranging from 1.36 to 1.59. Despite the coarser granulometry of RAP compared to sand, the FRDI values were not substantially higher. This suggests that the presence of the asphalt binder may have mitigated the impact of mechanical damage, reducing the severity of stress on the geogrids. The results obtained in this study highlight the importance of considering specific reduction factors for alternative backfill materials and reveal the significance of ensuring adequate quality of the polymeric coating on geogrids.
Biomarcadores bioquímicos em anuros expostos ao glifosato: uma revisão sistemática
(Universidade Federal de São Carlos, 2025-05-09) Vicente, Mariana Canutti Mariano; Salla, Raquel Fernanda; https://lattes.cnpq.br/1738422158151824; https://orcid.org/0000-0003-3275-0001; Carvalho, Cleoni dos Santos; https://lattes.cnpq.br/7233550271936621; https://orcid.org/0000-0003-0755-5239; https://lattes.cnpq.br/0208534406206549; https://orcid.org/0000-0002-4731-1442
Glyphosate, one of the most widely used herbicides in the world, is capable of generating lethal and sublethal effects on several types of organisms, especially in anurans that, during their development, move between the aquatic and terrestrial environments. Amphibians are organisms vulnerable to extinction due to deforestation and habitat loss, diseases, climate change, and high sensitivity to xenobiotics found in the environment, such as pesticides, for example. Therefore, it is essential to understand the development of studies in the area of herbicides and gaps that have not yet been filled. In this review, four databases were used to search for articles that dealt with biochemical biomarkers in anurans exposed to glyphosate. Twenty-five articles published between 2007 and 2023 were found, distributed in six countries, with the largest number being Brazil and Argentina, which is due to the large community of study groups in ecotoxicology, as well as the high consumption of glyphosate. Although the search consisted of amphibians, only studies with anurans were found, whose most used species were Rhinella arenarum, Aquarana catesbeiana and Xenopus laevis. In addition, 48% of the studies used enzymatic pathways to evaluate oxidative stress and neurotoxicity, followed by analyses in the liver (24%) and metabolism (16%). Regarding the life stage of the anurans evaluated, 92% of the studies used tadpoles and only 8% investigated adults. All studies reported oxidative stress and enzymatic alterations related to the exposure of amphibians to glyphosate alone or in mixture with other pesticides, demonstrating its capacity to compromise fundamental processes ranging from birth to reproduction of these individuals. However, the number of studies is still insufficient, as it is necessary to find an economically and environmentally effective solution to the unbridled use of glyphosate. Therefore, this review demonstrates the need to carry out further studies related to biochemical biomarkers and effects of glyphosate in amphibians.
Potencial biotecnológico da comunidade bacteriana endofítica associada a Paspalum vaginatum Swartz na promoção de crescimento vegetal, biocontrole e solubilização de fósforo de rochas fosfatadas
(Universidade Federal de São Carlos, 2025-05-09) Fernandes, Ana Carolina Vasconcelos; Favero, Alessandra Pereira; https://lattes.cnpq.br/4329892306148506; https://orcid.org/0000-0001-9461-1539; Lacava, Paulo Teixeira; https://lattes.cnpq.br/8947678349043750; https://orcid.org/0000-0001-7166-606X; https://lattes.cnpq.br/5201364823500867; https://orcid.org/0009-0004-0486-2975
Paspalum species are important constituents of native pastures in tropical and subtropical regions of the Americas. Paspalum vaginatum is a native grass to coastal areas in Brazil and is widely used on golf courses in the United States due to its robustness and tolerance to abiotic stresses such as drought, waterlogging, and salinity. Endophytic bacteria present within plant tissues can stimulate their growth and act in the biological control of phytopathogenic organisms. The present study aimed to evaluate the endophytic microbial diversity isolated from Paspalum vaginatum and determine their ability to promote plant growth, in addition to investigating the biotechnological potential of these microorganisms for in vitro phytopathogenic biological control in the laboratory and for the solubilization of different phosphorus sources in vitro and in plant. The 16S rDNA gene of 70 endophytic bacteria isolated from Paspalum vaginatum was sequenced for taxonomic identification purposes. Tests were performed to evaluate antagonism against Colletotrichum sp. and the solubilization capacity of different phosphorus sources such as Rochas Araxá and Bayovar, calcium phosphate and triple superphosphate in vitro. In addition, greenhouse experiments were conducted to study the growth stimulation of the species Paspalum vaginatum and Paspalum maritimum and a phosphorus solubilizing experiment on Paspalum maritimum. Molecular analysis revealed the presence of 17 bacterial genera, with emphasis on Bacillus (34.3%), followed by Agrobacterium and Micrococcus (10% each). The seven bacterial isolates tested were able to solubilize the four different phosphorus sources, with emphasis on Bac 160, Bac 161 and Bac 179. Regarding the antagonistic activity against Colletotrichum sp., it was identified that 13 isolates demonstrated antagonistic activity to the fungus Colletotrichum sp. and presented inhibition index ranging from 12.9% to 43.1%. In the plant growth promotion experiment on Paspalum vaginatum shoot dry weight, plant height and number of basal tillers, the commercial inoculants BiomaPhos® and Biopasto® presented inferior results when compared to the other available treatments. Furthermore, Biopasto® presented inferior results when compared to the other available treatments in relation to the number of aerial tillers in Paspalum vaginatum. In Paspalum maritimum, two varieties of Pantoea sp. contributed to a significant increase in root dry weight compared to the control group, and Biopasto® presented inferior results when compared to the other available treatments for shoot and root dry weight. The collected data point to the biotechnological potential of the endophytic bacterial strains identified in Paspalum vaginatum, indicating possible promising applications in sustainable agriculture both to stimulate plant growth and in the biological control of phytopathogenic organisms. The in plant phosphorus solubilization experiment using Paspalum maritimum was conducted with the isolates Bac 160, Bac 161, and Bac 179. Bac 161 showed favorable results for its use with insoluble phosphorus sources, such as Bayovar phosphate rock, both for shoot and root dry matter. Meanwhile, Bac 160 showed favorable results for use in combination with a soluble phosphorus source in order to enhance its effect.
Propriedades mecânicas de argamassas geopoliméricas com a incorporação de pó de vidro e fibra metálica
(Universidade Federal de São Carlos, 2025-05-09) Vasconcelos, Arthur de Sousa Lima; Ferreira, Fernanda Giannotti da Silva; https://lattes.cnpq.br/0329487394818763; https://orcid.org/0000-0002-2197-9081; https://lattes.cnpq.br/3144392961222299; https://orcid.org/0000-0002-5504-4516
The growing need for alternatives to Portland cement is driving the development of sustainable composites. This study evaluated geopolymer mortars based on metakaolin, incorporating glass powder waste, added alumina and reinforced with straight metal fibers, with the aim of investigating the technical feasibility and use of solid waste. Formulations were developed with a partial substitution of 20% of the metakaolin with glass powder and added alumina, and metal fiber contents of 1.0%, 1.5% and 2.0% by volume. The experimental program included tests of consistency index in the fresh state and in the hardened state, axial compressive strength, flexural tensile strength, diametrical compressive strength, dynamic modulus of elasticity, mass density and double punching tensile strength. Microstructural characterizations were carried out using XRD, FTIR and SEM. The results showed that the addition of 2.0% metal fibers promoted a significant increase in flexural tensile strength of 176.69% (15.43 MPa) and axial compressive strength of 46.82% (66.21 MPa). However, the formulation with 1.5% fibers exhibited the best overall performance in terms of mechanical properties, as well as providing increased toughness and improved post-cracking behavior, reducing the initial fragility of the mortars, without compromising the consistency index in the fresh state in relation to the reference. Microstructural characterization showed the consolidation of hydrated sodium aluminosilicate (N-A-S-H) gels with a well-defined structure in the reference composition. The partial incorporation of glass powder and alumina resulted in an increase in the amorphous phase, as shown by Rietveld analysis, indicating changes in the structure of the geopolymer matrix, which was reflected in a reduction in mechanical properties. Nevertheless, the formulations containing glass powder showed adequate performance for structural applications, corroborating the technical viability of using industrial by-products in geopolymer systems as a sustainable alternative for the construction sector.
Pegada hídrica e eficiência no uso da água: um estudo comparativo do cultivo da cana-de-açúcar em diferentes municípios no noroeste paulista
(Universidade Federal de São Carlos, 2025-05-09) Silva, Alonso; Moschini, Luiz Eduardo; https://lattes.cnpq.br/2728357583462262; https://lattes.cnpq.br/2455541604860503; Moschini, Luiz; Trevisan, Diego; Dayana, Almeida; https://lattes.cnpq.br/2728357583462262; https://lattes.cnpq.br/2413871825446601; https://lattes.cnpq.br/8099346855929913
This study analyzes the water footprint of sugarcane cultivation through a comparative assessment between the municipalities of Jales and Ituverava, both located in the northwest region of São Paulo, Brazil. The research aims to understand how edaphoclimatic characteristics and land use history influence the water demand of sugarcane crops, proposing measures to increase the crop's climate resilience. The methodology for measuring the water footprint was based on the CROPWAT 8.0 software, using climate data from the National Institute of Meteorology (INMET) and productivity data from the Brazilian Institute of Geography and Statistics (IBGE). The selected municipalities present relevant contrasts in terms of soil type (Latosol and Argisol) and agricultural land use history, enabling the evaluation of these factors' influence on the water footprint of sugarcane cultivation. The results indicate that despite higher rainfall and better water storage capacity in Ituverava’s soil, the municipality exhibits a higher water footprint than Jales, requiring more water per ton of sugarcane produced. Additionally, the study demonstrates that climate change directly impacts crop productivity and water use efficiency, reinforcing the need for adaptation strategies in the agricultural sector. It also highlights the importance of incorporating water sustainability criteria into agricultural planning and agro environmental zoning, especially in regions vulnerable to climate change effects.