Navegando por Autor "MOREIRA, Debora Dias Costa"

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Acesso aberto (Open Access)
Estudo da influência da distribuição granulométrica dos finos de minério de ferro na liquefação durante o transporte marítimo
(Universidade Federal do Pará, 2022-05-06) MOREIRA, Debora Dias Costa; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
In recent decades, many incidents with bulk carriers have occurred due to the liquefaction of solid bulk cargoes, with iron ore being responsible for the largest volume of solid cargo business in the world. The liquefaction of solid bulk cargoes in bulk carriers has been one of the main causes of serious accidents, including loss of life and vessels. iron ore fines (IOF) are products prepared from the refining of iron ore and were reclassified, in 2011, by the International Maritime Organization (IMO), as a liquefiable material of the ' A group'. Currently, the transportable moisture limit (TML) is the only parameter used by the IMO to minimize the risk of liquefaction of 'Group A' cargoes for maritime transport. In this thesis, two methodologies were proposed to investigate the liquefaction potential of IOF, the first methodology aimed to classify the liquefaction potential of IOF samples considering the TML and the Coulomb cohesion factor and the second methodology aimed to use the table test of vibration for analysis of the liquefaction potential of the IOF through proposed indicators. The studies were performed with IOF samples prepared with particle sizes from 9.5 mm to 25 µm in different fines contents (particles < 150 µm) and moisture. In the first part of the thesis, the direct shear tests showed that the addition of fines content in the IOF samples provides great influence on the shear strength. It was also observed, through the Proctor/Fagerberg test and the flow table test, that the addition of fines content in the IOF samples produced an increase in TML. These results were used to propose a methodology for classifying the liquefaction potential of IOF. In the second part of the thesis, the modified Proctor/Fagerberg test showed that there is a transition fine content for the TML. Through the experimental methodology proposed for the vibration table test, it was observed that the liquefaction potential of the IOF has a correlation with the migration of moisture to the surface and values of void ratio, degree of saturation and density are equivalent to the methodology of modified Proctor/Fagerberg test compression. It ends with the proposition of the indicators, Ip and ISWC, which are useful parameters to evaluate the potential for liquefaction of IOF in samples with different contents of fines and moisture; for the tested IOF, Ip ≤ 3.63 indicated that there was no liquefaction and ISWC > 0 indicated liquefaction.
Acesso aberto (Open Access)
Segurança de barragens de rejeitos e impactos ambientais: uma revisão sobre a mineração de caulim em uma região amazônica
(Instituto Tocantinense de Educação Superior e Pesquisa, 2023-12) SILVA, Matheus Cavalcante; MOREIRA, Debora Dias Costa; ISHIHARA, Júnior Hiroyuki; MONTE, Christiane do Nascimento; SELFE, Ana Cristina Cavalcante; SOUZA, Jadelene Ramos de; FRANÇA, Carlos David Veiga
In Brazil, the state of Pará has received attention, especially for the production and processing of kaolin. On the other hand, the demand for such mineral inputs has led to the growth of tailings production, which represents risks, which can be evidenced in recent disasters involving mining dams. This study consists of a systematic bibliographical review and aimed at discussing related methods of processing, kaolin storage and numerous incidents involving waste leaks, in order to support actions to detect the most impacted areas. The results demonstrated that the processing of kaolin ore in the study area is carried out via the wet process. Kaolin tailings storage systems in Barcarena-PA are more unsafe in relation to alternative disposal systems, resulting in events of kaolin tailings leaking into regional water bodies and spreading areas used for bathing.
Acesso aberto (Open Access)
O sistema de abastecimento de água de Tucuruí: caracterização e perspectiva histórica da gestão pública local
(Universidade Federal do Pará, 2014-03-20) MOREIRA, Debora Dias Costa; FARIAS, André Luís Assunção de; http://lattes.cnpq.br/5310171409459863; ROCHA, Gilberto de Miranda; http://lattes.cnpq.br/2436176783315749
The concerns raised with the reality of water resources, ie, water intended for usage, have led, worldwide, a number of governmental and social measures aiming to facilitate continuity of several public and private activities that focus freshwaters, in particular those which directly affect the quality of life. In order to understand this problem of multiple use of water that this research seeks to understand how was the process of expanding the water supply service in the city of Tucuruí, in view of the great demand established by the socio-spatial transformations , motivated by construction of the second stage Tucuruí (1998 to 2006). This analysis will also focus on public actions developed and adopted to solve the problems of lack of infrastructure experienced as a result of local population dynamics due to the construction of Tucuruí. Given the evolutionary process of the municipality of Tucuruí while scale government comes to the conclusion that the infrastructure of the water supply system, since 1970, was never planned. All public actions were to meet needs which have arisen over the years, due to a succession of major works, who requested the water supply system is a high demand service.