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The Igarape Weir decelerated transport of contaminated sediment in the Paraopeba River after the failure of the B1 tailings dam(Brumadinho)

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International Journal of Sediment Research 2023年第5期38卷 673-697页

作者： Daniela Patrícia Salgado Terêncio Fernando António Leal Pacheco renato farias do valle junior Maytê Maria Abreu Pires de Melo Silva Teresa Cristina Tarlé Pissarra Marília Carvalho de Melo Carlos Alberto Valera Luís Filipe Sanches Fernandes Inov4Agro/Centro de Investiga??o e Tecnologias Agroambientais e Biológicas Universidade de Trás-os-Montes e Alto Douro Centro de Química de Vila Real Universidade de Trás-os-Montes e Alto Douro Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista(UNESP) Via de Acesso Prof.Paulo Donato Castellane Instituto Federal do Triangulo Mineiro Campus Uberaba Laboratório de Geoprossessamento 5. Secretaria de Estado de Meio Ambiente e Desenvolvimento Sustentável Cidade Administrativa do Estado de Minas Gerais Rodovia Jo?o Paulo II 6. Coordenadoria Regional das Promotorias de Justi?a do Meio Ambiente das Bacias dos Rios Paranaíba e Baixo Rio Grande Rua Coronel Ant?nio Rios

The B1 dam of Co rrego do Feij～ao Mine, owned by Vale, S.A. mining company and located on the FerroCarv～ao stream, collapsed and injected 2.8 Mm3of clayey, silty, and sandy iron-and manganese-rich tailings into the Paraopeba River(Minas Gerais state, Brazil). The accident occurred on 25 January2019 and the tailings have been co-transported with coarser natural sediment since then, being partly trapped in the Igarape Weir reservoir located on the Paraopeba River nearly 45 km downstream the injection point. The general purpose of the current study was to model suspended sediment transport in the vicinity of the Igarape Weir aiming to assess the concomitant barrier effect imposed by this ***, the spatial distributions of suspended clay, silt, and very fine-grained sand fractions(CSS) of sediment were mapped around the Igarape Weir under low-flow(16 m3/s) and high-flow(5 to 10,000years return period stream discharge; 699—2,699 m3/s) regimes, using RiverFlow2D as the modelling tool. The concentrations of the various grain materials in the upstream and downstream sectors were quantified linking the barrier effect to concentration reductions in the direction of stream flow. It was also a study goal to calculate differences of iron and manganese concentrations in the sediment + tailings mixtures along the Paraopeba River. The study results showed reductions in the CSS between 6.6% and18%, from upstream to downstream of the Igarape Weir, related with backwater effects, free and submerged hydraulic jumps, bank sedimentation in periods of high flow, and streambed sedimentation controlled by channel sinuosity and tailings density. These reductions were accompanied by drops in the concentrations of iron and manganese present in the clay and silt fractions, which varied between 6% and42% under low flows and between 16% and 44% under high flows. Bank sedimentation was viewed as a potential threat to the riparian vegetation in the long-term. Dredging is the poten

关键词： Sediment transport Tailings dam break Metal contamination Hydrodynamic modelling RiverFlow2D Ratio concentration analysis

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Critical state model for structured soil

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第3期12卷 630-641页

作者： Cristhian Mendoza Marcio Muniz de farias Department of Civil Engineering Universidad Nacional de Colombia Sede ManizalesManizalesColombia Department of Civil and Environmental Engineering University of BrasiliaBrasiliaDFBrazil

Structure is an evident determinant for macroscopic behaviors of ***,this is not taken into account in most constitutive models,as structure is a rather complex issue in *** this,it is important to develop and implement simple models that can reflect this important aspect of soil *** paper tried to model structured soils based on well-established concepts,such as critical state and *** state is the core of the classic Cam Clay *** sub-loading concept implies adoption of an inner(sub-loading)yield surface,according to specific hardening rules for some internal strain-like state *** and co-workers proposed such internal variables for controlling density(p)and structure(ω),using a modified stress space,called ***,similar variables are used in the context of the better-known invariants(p and q)of the Cam Clay *** change requires explicit adoption of a non-associated flow rule for the sub-loading *** is accomplished by modifying the dilatancy ratio of the Cam Clay model,as a function of the new internal *** modifications are described and implemented under three-dimensional(3D)*** model is then applied to simulating laboratory tests under different stress paths and the results are compared to experiments reported for different types of structured *** good agreements show the capacity and potential of the proposed model.

关键词： Elastoplasticity Cam clay with sub-loading Structured soil Tropical soil Non-associated flow rule

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Antiglycation and antioxidant activities of the crude extract and saponin fraction of Tribulus terrestris before and after microcapsule release

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Journal of Integrative Medicine 2022年第2期20卷 153-162页

作者： Célia Cristina Malaguti Figueiredo Amanda da Costa Gomes Filipe Oliveira Granero Joao Luiz Bronzel junior Luciana Pereira Silva Valdecir farias Ximenes Regildo Márcio Goncalves da Silva Institute of Chemistry São Paulo State UniversityAraraquaraSão Paulo 14800-060Brazil Educational Foundation of the City of Assis AssisSão Paulo 19807-130Brazil Department of Chemistry School of SciencesSão Paulo State UniversityBauruSão Paulo 17033-360Brazil Department of Biotechnology School of SciencesHumanities and LanguagesSão Paulo State UniversityAssisSão Paulo 19806-900Brazil

Objective:The present study investigated antiglycation and antioxidant activities of crude dry extract and saponin fraction of Tribulus *** also developed a method of microencapsulation and evaluated antiglycation and antioxidant activities of crude dry extract and saponin fraction before and after microcapsule ***:Antiglycation activity was determined by relative electrophoretic mobility(REM),free amino groups and inhibition of advanced glycation end-product(AGE)*** activity was determined by 2,2-diphenyl-1-picrylhydrazyl(DPPH),ferric ion-reducing antioxidant power(FRAP),nitric oxide(NO)and thiobarbituric acid reactive species(TBARS)*** were prepared using maltodextrin as wall material and freeze-drying as encapsulation *** characterization of microcapsules was evaluated by scanning electron microscopy,and encapsulation efficiency and microcapsule release were determined by total saponins *** and antioxidant assays were performed using crude dry extract and saponin fraction of *** before and after ***:Saponin fraction showed an increase of 32.8%total ***-performance liquid chromatography-mass spectrometry analysis showed the presence of saponins in the obtained *** evaluation by REM demonstrated that samples before and after release presented antiglycation activity similar to bovine serum albumin treated with ***,samples inhibited AGE formation,highlighting treatment with saponin fraction after release(89.89%).Antioxidant tests demonstrated antioxidant activity of the *** dry extract before encapsulation presented the highest activities in DPPH(92.00%)and TBARS(32.49%)*** fraction before encapsulation in FRAP test(499μmol Trolox equivalent per gram of dry sample)and NO test(15.13μmol nitrite formed per gram of extract)presented the highest ***:This study presen

关键词： Glycation Microencapsulation Oxidative stress Saponins Tribulus terrestris

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Water-induced hydrogenation of graphene/metal interfaces at room temperature:Insights on water intercalation and identification of sites for water splitting

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Nano Research 2019年第12期12卷 3101-3108页

作者： Guangyu He Qi Wang Hak Ki Yu Daniel farias Yingchun Liu Antonio Politano Department of Chemistry Zhejiang UniversityHangzhou 310027China Department of Materials Science and Engineering and Department of Energy Systems Research Ajou UniversitySuwon 16499Republic of Korea Departamento de Ftsica de la Materia Condensada Universidad Autonoma de MadridMadrid 28049Spain Instituto"Nicolas Cabrera"and Condensed Matter Physics Center(IFIMAC) Universidad Autonoma de MadridMadrid 28049Spain Department of Physical and Chemical Sciences University of L'AquilaVia Vetoio 10L'Aquila 1-67100Italy CNR-IMM Istituto per la Microelettronica e Microsistemi VIII strada 5Catania 1-95121Italy

Though it is well recognized that the space between graphene cover and the metal substrate canact as a two-dimensional(2D)nanoreactor,several issues are still unresolved,including the role of the metal substrate,the mechanisms ruling water intercalation and the identification ofsites at which water is ***,we solve these issues by means of density functional theory and high-resolution electron energyloss spectroscopy experiments carried out on graphene grown on(111)-oriented Cu ***,we observe decomposition of H2O atroom temperature with only H atoms forming bonds with graphene and with buried OH groups underneath the graphene *** model discloses physicochemical mechanisms ruling the migration and decomposition of water on graphene/*** discover thatthe edge of graphene can be easily saturated by H through decomposition of H2O,which allows H2O to migrate in the subsurface region from thedecoupled edge,where H2O decomposes at room *** atoms produced by the decomposition of H2O initially form a chemicalbond with graphene for the lower energy barrier compared with other *** findings are essential to exploit graphene/Cu interfaces incatalysis and in energy-related applications.

关键词： graphene/metal interfaces intercalation water splitting room temperature

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Gastrointestinal motility and absorptive disorders in patients with inflammatory bowel diseases: Prevalence, diagnosis and treatment

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World Journal of Gastroenterology 2019年第31期25卷 4414-4426页

作者： Luísa Leite Barros Alberto Queiroz farias Ali Rezaie Department of Gastroenterology University of Sao Paulo School of MedicineSao Paulo 05403-000Brazil Division of Gastroenterology Department of MedicineCedars Sinai Medical CenterLos AngelesCA 90048United States

Inflammatory bowel diseases(IBD),Crohns disease and ulcerative colitis,are chronic conditions associated with high morbidity and healthcare *** natural history of IBD is variable and marked by alternating periods of flare and *** though the use of newer therapeutic targets has been associated with higher rates of mucosal healing,a great proportion of IBD patients remain symptomatic despite effective control of *** symptoms may include but not limited to abdominal pain,dyspepsia,diarrhea,urgency,fecal incontinence,constipation or *** this setting,commonly there is an overlap with gastrointestinal(GI)motility and absorptive *** recognition of these conditions greatly improves patient care and may decrease the risk of ***,in this review we describe the prevalence,diagnosis and treatment of GI motility and absorptive disorders that commonly affect patients with IBD.

关键词： Inflammatory bowel diseases Crohn’s disease Ulcerative colitis Gastrointestinal motility and absorptive disorders Irritable bowel syndrome Small intestinal bacterial overgrowth Small intestinal fungal overgrowth Dyssynergic defecation Fecal incontinence Chronic intestinal pseudo-obstruction

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Highly degradable chitosan-montmorillonite (MMT) nanocomposite hydrogel for controlled fertilizer release

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Frontiers of Environmental Science & Engineering 2023年第5期17卷 1-11页

作者： Zeou dou Maria Vitoria Bini farias Wensi Chen dongjing He Yuhang Hu Xing Xie School of Civil and Environmental Engineering Georgia Institute of TechnologyAtlantaGA 30332USA George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlantaGA 30332USA School of Chemical and Biomolecular Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

Fertilizer consumption is increasing drastically along with the rapid expansion of farming in response to the ever-growing population. However, a significant portion of the nutrients in traditional fertilizers is lost during leaching and runoff causing economic loss and environmental threats. Polymer-modified controlled-release fertilizers provide an opportunity for mitigating adverse environmental effects and increasing the profitability of crop production. Here, we present a cheap and easy-to-fabricate controlled-release fertilizer excipient based on hydrogels scaffolded by safe and biodegradable chitosan and montmorillonite (MMT) nanoclays. By introducing elastic and flexible physical crosslinking induced by 2-dimensional (2D) MMT nanoflakes into the chitosan hydrogel, highly swellable and degradable chitosan-MMT nanocomposites were fabricated. The addition of MMT into the chitosan hydrogels enhanced the total release of phosphorous (P) and potassium (K), from 22.0 % to 94.9 % and 9.6% to 31.4 %, respectively, compared to the pure chitosan gel. The chitosan-MMT nanocomposite hydrogel achieved a well-controlled overall fertilizer release in soil. A total of 55.3 % of loaded fertilizer was released over 15 d with a daily release of 2.8 %. For the traditional fertilizer podwer, 89.2 % of the fertilizer was washed out during the first irrigation under the same setup. In the meantime, the nanocomposites improved the water retention of the soil, thanks to its excellent water absorbency. Moreover, the chitosan-MMT nanocomposite hydrogels exhibited high degradation of 57 % after swelling in water for 20 d. Such highly degradable fertilizer excipient poses minimal threat to the long-term fertility of the soil. The engineered Chitosan-MMT biopolymer scaffold as a controlled-release fertilizer excipient provides a promising opportunity for advancing sustainable agriculture.

关键词： Biopolymer Hydrogel Controlled-release fertilizer Nanoclay Nanocomposite

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Effect of operating conditions and potassium content on Fischer-Tropsch liquid products produced by potassium-promoted iron catalysts

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Journal of Natural Gas Chemistry 2008年第2期17卷 175-178页

作者： Francisco E.M.farias Fernando G.Sales Fabiano A.N.Fernandes Universidade Federal do Ceará Departamento de Engenharia QuímicaCampus do PiciBloco 70960455-760 Fortaleza-CEBrazil

The dependencies of Fischer-Tropsch synthesis liquid hydrocarbon product distribution on operating pressure and temperature have been studied over three potassium-promoted iron catalysts with increasing potassium molar content. The study followed an experimental planning and the results were analyzed based on surface response methodology. The effects of different operating conditions and potassium contents on the liquid product distribution were compared based on number average carbon number and dispersion. Results showed that high pressures （25 to 30 arm） favored the production of waxes that could be converted into liquid fuels through hydrocracking, while greater direct selectivity towards diesel was favored by low pressure （20 arm） using catalysts with low potassium to iron molar ratios. The liquid product distribution produced using an iron catalyst with high potassium content presented higher number-average number of carbons when compared to the distribution obtained using an iron catalyst with low potassium content.

关键词： Fischer-Tropsch synthesis liquid fuels iron-based catalyst potassium

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Pseudo-discontinuum model to simulate hard-rock mine pillars

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Underground Space 2023年第4期11卷 81-95页

作者： Erick Ro genes Alessandra dos Santos Gomes Marcio Muniz de farias Leandro Lima Rasmussen Faculty of Technology University of BrasiliaDF 70910-900BrasiliaBrazil

In this study,the pseudo-discontinuum modeling technique,called continuum Voronoi block model(CVBM),was applied to repre-sent the behavior of hard-rock pillars from underground mines subjected to high field *** CVBM’s ability to produce numerical results consistent with the observed behavior of pillars is demonstrated through the numerical analysis of a hypothetical case and a back analysis of the Creighton mine *** results show that the model can capture convergence displacements and explicitly show the formation of macro-fractures parallel to excavation walls,intact rock slabs,and V-shaped *** components are characteristics of brittle failure induced by highly stressed ground *** studies presented in this work confirm the CVBM as a convenient tool for the numerical modeling of intact rock pillars excavated in deep underground mines.

关键词： Brittle failure Spalling Bulking Voronoi tessellation

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Small river basin and estuarine sediment fluxes:The magnitude necessary for coastal dispersion and siltation effects on a coral reef

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International Journal of Sediment Research 2019年第6期34卷 591-599页

作者： Paula Sagili?o Isacksson Eduardo Guilherme Gentil de farias Francisco José Dias Roberto Nascimento de farias Anandra Machado Francisco de Assis Esteves Mauricio Mussi Molisani Instituto de Biodiversidade e Sustentabilidade (NUPEM/UFRJ) Universidade Federal do Rio de Janeiro Grupo de Gestao Ecologia e Tecnologia Marinha (GTMar)Departamento de Engenharia de Pesca a Ciencias Biologicas (DEPB)Universidade do Estado de Santa Catarina (UESC) Laboratorio de Hidrodinamica Costeira Estuarina e de Aguas Interiores (LHiCEAI)Departamento de Oceanografia e Limnologia (DEOLI)Universidade Federal do Maranhao (UFMA) Programa de Pos-Graduacao em Ciencias Ambientais e Conservacao-PPGCIAC Instituto de Biodiversidade e Sustentabilidade (NUPEM/UFRJ)

Increasing continental suspended sediment influx to coral reefs is an example of land-sea coupling that requires the identification of sources,magnitude of transport,and controlling *** Brazil,a small coastal basin(Macae River) was identified as a source of suspended sediment to a coral reef on the coast of Cape Armacao dos *** suspended sediment loads were measured at the basin as were fluxes within the estuary and towards the coast during eight tidal *** load and yield from this basin were typical of small coastal basins,showing high to moderate slopes and transitional land ***,the magnitude of the river loads was lower than the sediment transport within the estuary,indicating that the estuary amplifies river fluxes and sustains the transference of suspended sediment alongshore to the coral ***,the estuary displays both suspended particle retention and export capacity and,therefore,fluxes to the coast and the coral reef occur as episodic events.

关键词： Suspended matter Watershed Mass-balance budget Campos Basin

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Acute kidney injury in leptospirosis:Overview and perspectives

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Asian Pacific Journal of Tropical Medicine 2018年第10期11卷 549-554页

作者： Geraldo Bezerra da Silva junior Nattachai Srisawat Gabriela Studart Galdino ênio Sima Macedo JoséReginaldo Pinto Geysa Maria Nogueira farias Renan Lima Alencar Roberto da Justa Pires Neto Elvino JoséGuardao Barros Elizabeth De Francesco Daher Medical Sciences and Public Health and Graduate Programs School of Medicine Health Sciences Center University of Fortaleza Excellence Center for Critical Care Nephrology Division of Nephrology Department of Medicine Chulalongkorn University Collaborating CRISMA faculty member Department of Critical Care Medicine Univeristy of Pittsburgh School of Medicine Medical Sciences and Public Health Graduate Programs Department of Internal Medicine School of Medicine Federal University of Ceara Department of Internal Medicine School of Medicine Federal University of Rio Grande do Sul

Leptospirosis is a bacterial disease disseminated through the centuries in the whole world which causes symptoms that go from self-limited diseases to hemorrhagic manifestations and organ failure, including acute kidney injury(AKI), composing the severe disease known as the Weil's syndrome. Mortality rates varies according to the clinical presentation and usually increases when kidney injury is present, and is even higher in the setting of pulmonary hemorrhage. There are recent advances in the search for novel biomarkers of renal involvement and early detection of AKI in leptospirosis, as well as in its pathophysiology. We review in this article the clinical aspects of leptospirosis-associated AKI and the perspectives for future research.

关键词： Leptospirosis Acute kidney injury Perspectives Bacterial infections

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