Brazil, one of the largest ore producers in the world, holds 95% of the world’s quartz reserves. The aim of this research is to enhance mitigation measures in quartz ore exploration common in the Serra do Espinhaço Meridional region through the specific study of a mining venture. The three (3) phases of the study were: (1) characterization of the project under study and evaluation of the impacts generated; (2) evaluation of the economic feasibility of using the waste as a coarse aggregate for concrete production; (3) evaluation of the technical feasibility of reusing this waste through analysis of compressive strength. The results of the study show potential negative impacts on occupational health from the piles of disposed waste, specifically silicosis, caused by silica dust dispersed in the air. In the economic analysis, a decrease of 49.05% was verified in coarse aggregate cost through the use of the residue. The compressive strength of the concrete was 26.80 MPa when quartz residue was used and 29.2 MPa when limestone was used. The quartz residue generated by the venture can be reused as aggregate for the production of concrete, generating improvements in environmental and health aspects.

In the present study, a cluster analysis, in relation to the species composition of the catches, was used to classify 6,486 fishing sets by a longline fleet based in São Paulo State, Brazil, from 1998 to 2006. Based on the proportions of 12 species and three broader species groups, three clusters were identified: C1: other fishes; C2: blue shark; C3: swordfish. Results indicated that the fleet targeted mainly blue shark and swordfish and also showed that the blue shark importance in this fishery has been growing progressively trough the years. Offshore areas were exploited mainly in the first and fourth quarters (from 2001 mainly), while the fishing effort was more concentrated near the continental shelf break, during the second and third quarters (for the whole period). The longline fishery based in Sao Paulo State changed fishing strategy to target different species which produced important changes in catch-per-unit-effort (CPUE) of the main species caught. Cluster analysis seems to have appropriately identified these changes over time, which is an important information, often missing in logbooks.

Soil-cement is a building material that is considered low-cost and has a low environmental impact. Despite its benefits, performance optimisation studies are scarce compared to other materials such as concrete. The possibility of obtaining soil-cement with improved characteristics, such as flexural strength, would enable the increased use of this product in new applications in construction. The aim of this study is to produce high-performance soil-cement (HPSC) specimens and to evaluate and compare this new material with high-performance concrete (HPC) in terms of flexural strength. A total of 12 specimens were produced with a mixture of 23.5% (by mass) of cement with the application of 10 MPa of pressure for its compaction. The results show that, at 28 days, the specimens reached an average strength of 6.73 MPa and, at 240 days, 12.34 MPa. This means that the HPSC reached a flexural strength resistance equivalent to HPC without the need for mined materials, such as sand and gravel, or the additives adopted in some doses of HPC, such as superplasticisers. Therefore, when using local soil, HPSC can be considered an environmentally preferable alternative to HPC for many construction applications where flexural strength is a requirement.

Current studies indicate that it is possible to obtain soil-cement products with similar performances to high performance concrete (HPC). In this context, this work aimed to evaluate the flexural rupture parameters of high-performance soil-cement specimens (HPSC) in relation to the cement percentage. Eighteen HPSC specimens were analyzed, produced with compaction moisture of 13% and pressure of 1.2 MPa. The average flexural-tensile strength of the specimens was 4.6 MPa with 30% cement, 5.6 MPa with 40% cement and 5.8 MPa with 50% cement. The results indicate the possibility of using a new product (HPSC) with flexural-tensile strength equivalent to HPC, but without the need to use mining materials, such as sand, gravel and other additives like superplasticizers. This opens up the opportunity to produce new soil-cement artifacts, such as plates and/or floors, for which values of flexural-tensile strength higher than those currently obtained in concrete and/or soil-cement products are required.

Este estudo teve como objetivo principal analisar a correlação entre o teor de cimento e a resistência à compressão de corpos de prova de solo-cimento, com base em uma revisão sistemática da literatura. Foram analisados 26 artigos científicos, totalizando 227 dosagens avaliadas. As fontes selecionadas apresentavam informações quantitativas sobre teor de cimento, resistência à compressão e características de moldagem. Os dados foram organizados e analisados estatisticamente no software Microsoft Excel 2019, aplicando-se um modelo de regressão linear para avaliar a relação entre o teor de cimento e a resistência à compressão aos 28 dias de cura. Os resultados indicaram uma correlação positiva, porém de baixa magnitude (r = 0,31), sugerindo que o aumento do teor de cimento tende a elevar a resistência mecânica. Observou-se também que variáveis como tipo de solo, umidade, compactação e cura exercem influência significativa no desempenho do material. O estudo contribui para o aprimoramento de formulações de solo-cimento mais sustentáveis, com menor consumo de cimento e bom desempenho estrutural. As principais limitações relacionam-se à variabilidade das metodologias experimentais e à utilização de dados secundários. Recomenda-se a realização de pesquisas experimentais futuras para validar e expandir os resultados obtidos.

This article is the result of the Specialization Course in Geoprocessing of IFNMG, dealing with data survey of hydraulic structures of the old railway sub-track Diamantina to Monjolos, Minas Gerais, opened in May 1914, comprising 92.5km, with activities ended in 1973. Nowadays it is sought out by walkers and cyclists, and for contemplation of nature, presenting tourist potential. After the closing of the railway activities, its bridges and culverts have accumulated degradation processes over the years, due to lack of maintenance or even by natural or anthropic action. Understanding that to preserve it is necessary to know, through geotechnological principles, we proceeded to collect information in the field of these structures during 8 (eight) days between the end of 2020 and beginning of 2021, we elaborated the respective georeferenced database, adopted SRTM image for the generation of information about the local surface water network and generated thematic maps and tables about the collected and elaborated information. As an example of verification of hydraulic functioning, one of the ogival culverts was detailed, with dimensions collected in the field and respective hydrological and hydraulic studies based on the previously mentioned actions. The database generated was made available to the project Trilha Verde da Maria Fumaça, in the process of creating the management council of the sub-track, which was passed on to the City Halls of Diamantina and Gouveia, with the aim of triggering the attention of the competent bodies, in order to maintain the stretch in usable conditions for present and future generations.