Underground
Mostrando 1-12 de 359 artigos, teses e dissertações.
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1. Unplanned dilution back analysis in an underground mine using numerical models
Abstract In underground mines, stability problems can cause unplanned dilution, increasing the costs of mining operations, such as loading, transport, crushing and grinding. This is usually dealt with by simply increasing investments with support. However, the design geometry of stopes and drifts also has a great effect on a stope’s stability. The use of e
REM - International Engineering Journal. Publicado em: 2022
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2. Memory and the neo-slave novel in Colson Whitehead’s The Underground Railroad and Ta-Nehisi Coates’ The Water Dancer
RESUMO Esta análise investiga dois romances afro-americanos recentes, a saber, The Underground Railroad (2016) de Colson Whitehead e The Water Dancer (2019) de Ta-nehisi Coates a partir das configurações propostas pelo gênero literário conhecido como narrativas neo-escravas. Essas narrativas são releituras ficcionais pós-modernas de narrativas escrava
Revista Brasileira de Literatura Comparada. Publicado em: 2022
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3. Geostatistical simulations with heterotopic hard and soft data without modeling the linear model of coregionalization
Abstract Most mining decisions are based on models estimated/simulated given the information obtained from samples. During the exploration stage, samples are commonly taken using diamond drill holes which are accurate and precise. These samples are considered hard data. In the production stage, new samples are added. These last are cheaper and more abundant
REM, Int. Eng. J.. Publicado em: 2021-06
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4. Geological - geotechnical characterization of different lithotypes in an underground mine
Abstract A mineralogical, geological and geotechnical characterization of several rock types (phyllite, dolomite, breccia and marl) from an underground mine site aimed, among other things, to identify its mineral composition and to provide parameters to support the understanding of rock mass behavior. For this purpose, it was possible to perform laboratory a
REM, Int. Eng. J.. Publicado em: 2021-01
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5. Strategies used to control the costs of underground ventilation in some Brazilian mines
Abstract In an underground mine, the ventilation is responsible for 25% to 50% of its electrical energy consumption. In countries such as South Africa, United States and Canada researchers have started to achieve a significant reduction in energy consumption without neglecting aspects of the quantity and quality of air required for the best performance of th
REM, Int. Eng. J.. Publicado em: 2020-12
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6. Open stope stability assessment through artificial intelligence
Abstract Underground mining is a set of methods that allows the extraction of ore in depth, ensuring sustainability and economic viability. One of the problems that arise in underground mine operations is open stope stability. The method for assessing stabil ity of open stopes is the stability graph proposed by Mathews et al. (1981). It is possible to estima
REM, Int. Eng. J.. Publicado em: 2020-09
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7. Peculiarities of drilling and blasting in underground small-scale mines
Abstract Artisanal and Small-scale Mining (ASM) is a prominent activity in the extractive industry: considering only gold, it produces about 20% of the world market supply. Despite this fact, ASM is generally associated with the negative aspects of its environ mental impact, and operational research is generally neglected. This article empha sizes the peculi
REM, Int. Eng. J.. Publicado em: 2020-09
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8. Chilean artisanal mining: a gambling scenario
Abstract One of the most characteristic aspects of artisanal mining is the lack of geological exploration. Going into production without previous exploration is here defined as a gambling scenario. The present study intended to quantify the risk associated to such gambling by analyzing the operations of an area of artisanal underground gold mining in central
REM, Int. Eng. J.. Publicado em: 2020-06
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9. A evolução histórica da drenagem urbana: da drenagem tradicional à sintonia com a natureza
RESUMO No Brasil, mais de 80% da população brasileira vive em cidades. Como consequência desse crescimento populacional, há impermeabilização do solo, ocupação das faixas marginais de proteção dos rios, desmatamentos, canalização de rios, quantidade crescente de resíduos sólidos que são jogados nesses corpos hídricos, dentre outras. Quando oc
Saúde debate. Publicado em: 13/01/2020
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10. Strontium Oxide Decorated Iron Oxide Activated Carbon Nanocomposite: A New Adsorbent for Removal of Nitrate from Well Water
In the present study, activated carbon was magnetized by iron oxide and modified by strontium based nanoparticles (FeAC@Sr) to introduce it as an efficient favorable adsorbent for the removal of nitrate ions from underground water. The decorated adsorbent was characterized in terms of size, structure, morphology and composition using scanning electron micros
J. Braz. Chem. Soc.. Publicado em: 2020-01
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11. Conexões entre artes de rua, criatividade e profissões: circuitos e criações de Tamara Alves
Resumo Este artigo é parte de uma etnografia realizada em Lisboa sobre arte urbana e graffiti. O texto evidencia as fluidas e porosas fronteiras que se desenham entre conexões e produções da arte urbana. Como caso exemplar, segui a trajetória da writer portuguesa Tamara Alves, que, além de “artista de rua”, se autoidentifica como designer gráfica,
Horiz. antropol.. Publicado em: 02/12/2019
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12. Analysis of the Levels of Alteration of Aquifers Caused by the Installation of Wind Farms on Dunes on the Coast of Ceará, Brazil
Resumo A pesquisa objetivou avaliar os níveis de alteração dos aquíferos a partir da instalação de parques eólicos sobre dunas no litoral do Ceará por meio dos métodos de vulnerabilidade GOD e POSH, fluxo subterrâneo e aplicação da análise multivariada para subsidiar no monitoramento da qualidade da água subterrânea na área. Foram realizadas
Rev. Ambient. Água. Publicado em: 25/11/2019