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Magnetic bearings with double crossed loops modelled with T-A formulation and electric circuits

Superconductivity 2023年第3期7卷 65-74页

作者： Bárbara Maria Oliveira Santos Gabriel dos Santos Flávio Goulart dos Reis Martins Felipe Sass Guilherme Gonçalves Sotelo Rubens de Andrade Junior Francesco Grilli Electrical engineering department Rio de Janeiro State UniversityRio de Janeiro20550-900Rio de JaneiroBrazil Electrical engineering department Universidade Federal FluminenseNiterói24210-240Rio de JaneiroBrazil Electrical engineering department Universidade Federal do Rio de JaneiroRio de Janeiro21941-909Rio de JaneiroBrazil Institute for Technical Physics Karlsruhe Institute of TechnologyKarlsruhe76131Germany

The application of High‐Temperature Superconductor(HTS)coils made of coated conductors has been investigated for many years.A possible configuration for such coils is the jointless loop,also known as the ring *** double crossed loop coil(DCLC)has been successfully applied in superconducting magnetic bearings(SMBs).The design of SMBs with DCLCs requires flexible modelling to allow all parts of the device to be *** work proposes the T‐A formulation with a thin‐film approximation for modelling SMB with DCLCs in the finite element analysis framework.A 2D representation of the system is coupled with an external electric circuit to model the continuity of the lines that represent the parts of each jointless *** couple the T‐A formulation and the circuit,an average of the total electric field,with both resistive and inductive components,is applied to the *** total current computed by the circuit is applied to the T‐A *** proposed methodology was validated by comparison with levitation force experimental *** types of tests were simulated:five levitation force tests and three guidance force *** is shown that there is a limit to the behaviour of the levitation force related to the high‐loss *** this limit,the stack of DCLCs behaves as an equivalent *** this limit,a high‐loss state appears as a linear growth of the levitation *** is also shown that this high‐loss state in vertical displacement influences the lateral force.

关键词： Coated conductors Jointless loops T‐A formulation

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Feasibility Assessment of Sugarcane Expansion in Southwest Goiás, Brazil Based on the GIS Technology

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Journal of Geographic Information System 2016年第2期8卷 149-162页

作者： Bruno Cardoso Pedrosa Tuani Cristine Lima de Souza Ana Paula Dias Turetta Heitor Luis da Costa Coutinho department of environmental engineering of pontifícia universidade católica of rio de janeiro Rio de Janeiro Brazil department of Geography of rio de janeiro Federal University Rio de Janeiro Brazil Brazilian Agricultural Research Corporation Nacional Center for Soil Research (EMBRAPA Soils) Rio de Janeiro Brazil

The current study approaches the sugarcane culture expansion in Southwestern Goiás, especially in Mineiros, Quirinópolis and rio Verde counties, which represent different times and responses to this process. The current logistics structure and future prospects for sugarcane and its derivatives transportation are studied at national level with emphasis to the aforementioned micro-region. Maps showing land use and land cover in three different years were generated from Landsat TM-5 satellite images and they were used to analyze the dynamics of changes in land use and in land cover. The region is marked by strong and rapid growth in the agricultural sector and its sugar-energy industry has been expanding in recent years, although with different aspects among its counties. Since it is a promising region in this sector, due to the favorable soil and weather conditions to the crop, the region requires more investment and planning in logistics to ensure production flow and to make it stronger within domestic and foreign markets.

关键词： GIS Land Use and Land Cover Sugarcane Expansion Sustainability

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Mercury in aquatic fauna contamination:A systematic review on its dynamics and potential health risks

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Journal of environmental Sciences 2019年第10期31卷 205-218页

作者： Paloma de Almeida Rodrigues Rafaela Gomes Ferrari Luciano Neves dos Santos Carlos Adam Conte Junior Molecular and Analytical Laboratory Center Department of Food TechnologyFaculty of VeterinaryUniversidade Federal FluminenseNiteróiBrazil Chemistry Institute Food Science ProgramUniversidade Federal do Rio de JaneiroRio de JaneiroBrazil National Institute of Health Quality Control Fundacaeo Oswaldo CruzRio de JaneiroBrazil Laboratory of Theoretical and Applied Ichthyology Department of Ecology and Marine ResourcesUniversidade Federal do Estado do Rio de JaneiroRio de JaneiroBrazil

Mercury is an important pollutant,released into aquatic ecosystems both naturally and by anthropogenic *** element is transferred to aquatic organisms in different ways,causing potential health *** addition,mercury can be accumulated by humans,especially through the consumption of contaminated *** systematic review aims to present mercury pathways,the major routes through which this element reaches the aquatic environment and its transformations until becoming available to living animals,leading to bioaccumulation and biomagnification *** key biotic and abiotic factors affecting such processes,the impact of mercury on animal and human health and the issue of seafood consumption as a source of chronic mercury contamination are also addressed.A total of 101 articles were retrieved from a standardized search on three databases(PubMed,Emabse,and Web of Science),in addition to 28 other studies not found on these databases but considered fundamental to this review(totaling 129 articles).Both biotic and abiotic factors display fundamental importance in mediating mercurial dynamics,i.e.,muscle tropism,and salinity,***,mercurial contamination in aquatic environments affects animal health,especially the risk of extinction species and also on human health,with methylmercury the main mercury species responsible for acute and chronic symptomatology.

关键词： Mercury levels Seafood Methylmercury Public health Aquatic environment

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Effect of a commercial dispersion of multi walled carbon nanotubes on the hydration of an oil well cementing paste

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Frontiers of Structural and Civil engineering 2016年第2期10卷 174-179页

作者： Ocar Aurelio MENDOZA REALES William C. PEARL Jr Maria D. M. PAIVA Cristiane R. MIRANDA Romildo Dias TOLEDO FILHO Civil engineering department PEC/COPPE Universidade Federal do Rio de Janeiro Rio de Janeiro 21941-972 Brazil Halliburton Brazil Technology Center Halliburton Rio de Janeiro 21941-907 Brazil CPetrobras Petroleo Brasileiro S.A Rio de Janeiro 21941-901 Brazil

This work studies the influence of a commercial dispersion of multi wall carbon nanotubes （MWCNT） on the hydration of a class G cement paste, at room and elevated down-hole temperatures. The MWCNT dispersion was produced with a solids concentration of 3.0 % by mass and an anionic surfactant as dispersing agent. Cement pastes with water-to-cement ratio of 0.45 and additions of solid MWCNT by mass of cement up to 0.50 % were studied. Isothermal calorimetry results showed a clear retardation of the hydration of cement caused by the surfactant contained in the MWCNT dispersion. Nevertheless, thermogravimetric evaluations showed that once the hydration reaction resumed, the retardation effect of the surfactant did not have a negative impact on the amount of hydration products precipitated. It was concluded that the commercial MWCNT dispersion presents a good potential to be applied in oil well cement pastes.

关键词： carbon nanotubes surfactant retardation combined water C-S-H

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Influence of variables related to soil weathering on the geomechanical performance of tropical soils

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Journal of Rock Mechanics and Geotechnical engineering 2023年第9期15卷 2423-2440页

作者： Rodrigo Cesar Pierozan Gregorio Luís Silva Araújo Ennio Marques Palmeira Celso Romanel department of Civil engineering Federal Institute of EducationScienceand Technology of RondoniaPorto VelhoROBrazil department of Civil and environmental engineering University of BrasiliaBrasiliaDFBrazil department of Civil and environmental engineering Pontifical Catholic University of Rio de JaneiroRio de JaneiroRJBrazil

This paper presents an experimental and analytical investigation of the influence of variables related to soil weathering on the geomechanical performance of sand-silt mixtures containing lateritic soils,*** weathered tropical soils with the influence of interparticle *** sand-silt mixtures containing different relative proportions between uniform sand and lateritic soil were produced,and geomechanical soil characterization tests were *** on the results,a transition from a primarily coarse-to a fine-grained prevailing soil structure was found to cause considerable impact on the geomechanical performance of these soils,as evidenced by design variables related to soil mineralogy and size distribution ***,fines contents of both individual soil particles and soil aggregations were found to correlate with experimental results,while the relative proportion between sesquioxides(aluminum,and iron oxides),and silica,***-silica ratios(SSR^(-1)),facilitated estimates concerning changes in geomechanical ***,the application of the sandsilt mixtures containing lateritic soil on soil walls reinforced with polymeric strips was also evaluated,further emphasizing the potential advantages of adopting variables related to soil weathering on design guidelines concerning tropical soils.

关键词： Sesquioxides-silica ratio Tropical soils Sand-silt mixtures Lateritic soil Reinforced soil walls

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An operator methodology for the global dynamic analysis of stochastic nonlinear systems

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Theoretical & Applied Mechanics Letters 2023年第3期13卷 164-169页

作者： Kaio C.B.Benedetti Paulo B.Goncalves Stefano Lenci Giuseppe Rega department of Civil and environmental engineering Pontifical Catholic University of Rio de JaneiroRio de JaneiroBrazil department of Civil and Building engineering and Architecture Polytechnic University of MarcheAnconaItaly department of Structural and Geotechnical engineering Sapienza University of RomeRomeItaly

In a global dynamic analysis,the coexisting attractors and their basins are the main tools to understand the system behavior and ***,both basins and attractors can be drastically influenced by *** aim of this work is to illustrate a methodology for the global dynamic analysis of nondeterministic dynamical systems with competing ***,analytical and numerical tools for calculation of nondeterministic global structures,namely attractors and basins,are ***,based on the definition of the Perron-Frobenius,Koopman and Foias linear operators,a global dynamic description through phase-space operators is presented for both deterministic and nondeterministic *** this context,the stochastic basins of attraction and attractors’distributions replace the usual basin and attractor ***,numerical implementation of these concepts is accomplished via an adaptative phase-space discretization strategy based on the classical Ulam *** results of the methodology are presented for a canonical dynamical system.

关键词： Stochastic dynamics Global nonlinear dynamics Coexisting attractors Operator methodology Adaptative discretization Noise

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Non-spherical multi-oscillations of a bubble in a compressible liquid

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Journal of Hydrodynamics 2014年第6期26卷 848-855页

作者： WANG Qian-xi YANG Yuan-xiang TAN Danielle SU Jian TAN Soon Keat School of Mathematics University of Birmingham Maritime Research Centre School of Civil and Environmental Engineering Nanyang Technological University Sweimann department of Mechanical engineering National University of Singapore Nuclear engineering Program COPPE Universidade Federal do Rio de Janeiro Nanyang Environment and Water Research Institute Nanyang Technological University

Bubble dynamics are associated with wide and important applications in cavitation erosion in many industrial systems, medical ultrasonics and underwater explosions. Two recent developments to this classical problem are reviewed in this paper. Firstly, computational studies on the problem have commonly been based on an incompressible fluid model. However, a bubble usually undergoes significantly damped oscillation due to the compressible effects. We model this phenomenon using weakly compressible theory and a modified boundary integral method. This model considers the energy loss due to shock waves emitted at minimum bubble volumes. Secondly, the computational studies so far have largely been concerned with the first-cycle of oscillation. However, a bubble usually oscillates for a few cycles before it breaks into much smaller ones. We model both the first- and second-cycles of oscillationand predict damped oscillations. Our computations correlate well with the experimental data.

关键词： compressible bubble dynamics weakly compressible theory boundary integral method

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Neoarchean and Rhyacian TTG-Sanukitoid suites in the southern S?o Francisco Paleocontinent,Brazil:Evidence for diachronous change towards modern tectonics

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Geoscience Frontiers 2020年第5期11卷 1763-1787页

作者： Henrique Bruno Vitalino Elizeu Monica Heilbron Claudio de Morisson Valeriano Rob Strachan Mike Fowler Samuel Bersan Hugo Moreira Ivo Dussin Luiz Guilherme do Eirado Silva Miguel Tupinamba Julio Almeida Carla Neto Craig Storey universidade Do Estado Do rio de janeiro Faculdade de GeologiaTektosGrupo de Pesquisa Em GeotectonicaRua Sao Francisco Xavier 524MaracanaRio de JaneiroBrazil University of Portsmouth School of Earth and Environmental SciencesBurnaby BuildingBurnaby RoadPortsmouthUK Universit€at Salzburg Department of Geography and GeologyKapitelgasse4-65020SalzburgAustria universidade Federal de Ouro Preto Departamento de GeologiaCampus Morro Do CruzeiroOuro PretoMGBrazil Laboratorio de Geocronologia e Isotopos Radiog^enicos Universidade Do Estado Do Rio de JaneiroRua Sao Francisco Xavier 524MaracanaRio de JaneiroBrazil

The southern portion of the Sao Francisco Palaeocontinent in Brazil is denoted by Archean nuclei and Paleoproterozoic magmatic arcs that were amalgamated during Siderian to Orosirian orogenic processes(ca.2.4-2.1 Ga).New isotopic U-Pb in zircon and Sm-Nd whole rock combined with major and trace element composition analyses constrain the crystallization history of the Neoarchean Piedade block(at ca.2.6 Ga)and the Paleoproterozoic Mantiqueira Complex(ca.2.1-1.9 Ga).These therefore display quite different magmatic histories prior to their amalgamation at ca.2.05 ***-Nd and Rb-Sr isotopes imply a mixed mantle-crustal origin for the samples in both units.A complete Palaeoproterozoic orogenic cycle,from subduction to collision and collapse,is recorded in the Piedade Block and the Mantiqueira *** to Orosirian subduction processes(ca.2.2-2.1 Ga)led to the generation of coeval(ca.2.16 Ga)TTG suites and sanukitoids,followed by late(2.10-2.02 Ga)high-K granitoids that mark the collisional *** collisional accretion of the Mantiqueira Complex against the Piedade Block at 2.08-2.04 Ga is also recorded by granulite facies metamorphism in the latter terrane,along the Ponte Nova suture *** collisional stage was closely followed by the emplacement of within-plate tholeiites at ca.2.04 Ga and by alkaline rocks(syenites and enriched basic rocks)at ca.1.98 Ga,marking the transition to an extensional tectonic *** discovery of two episodes of TTG and sanukitoid magmatism,one during the Neoarchean in the Piedade Complex and another during the Rhyacian in the Mantiqueira Complex,indicates that the onset of subduction-related melting of metasomatized mantle was not restricted to Neoarchean times,as generally believed,but persisted much later into the Paleoproterozoic.

关键词： Geodynamics High Ba–Sr granitoids Diachronous TTG-Sanukitoid transition Paleoproterozoic Mantiqueira complex

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environmental and Durability Perspective of the Use of Curaua Fiber Treated in Mortars

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Journal of Renewable Materials 2022年第9期10卷 2409-2429页

作者： Afonso R.G.de Azevedo Marcelo Nascimento Dirlane do Carmo Markssuel T.Marvila Gustavo de C.Xavier Sergio Neves Monteiro UENF-State University of the Northern rio de janeiro LECIV-Civil Engineering LaboratoryCampos dos GoytacazesBrazil UFF-Federal Fluminense University TER-Department of Agricultural EngineeringNiteróiBrazil UENF-State University of the Northern rio de janeiro LAMAV-Advanced Materials LaboratoryCampos dos GoytacazesBrazil IME-Military Institute of engineering Department of Materials ScienceRio de JaneiroBrazil

The use of natural lignocellulosic fibers(NLFs)as a reinforcement mechanism for cementitious composites,such as mortar,has been investigated in the last ***,their application has often been restricted to technological evaluation research.A NLF with great potential the curaua,which after treatment with NaOH solution,proved to be technologically feasible for mortars reinforcement based on cement and *** objective of this research was the comparative evaluation between a traditional mortar,based on cement and lime,with 1:1:6:0.8 ratio of cement:lime:sand:water,and a modified mortar with addition of 2 wt.%treated curaua fiber in cement mass by evaluating environmental and durability *** a curing time for 28 days,environmental assessments were carried out and durability methodologies were *** tests performed were:(i)attack by chlorides and sulfate,(ii)the wetting and drying cycles,and(iii)slake durability *** results showed that the mortar with the addition of curaua fiber presented a similar behavior to the reference mixture,both in terms of environmental and durability *** modified mortar is able to be used in internal and external environments,the latter with some ***,it also contributes to the promotion of sustainable use of curaua fiber.

关键词： Natural lignocellulosic fibers curaua mortar durability environmental aspects

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Non-alcoholic fatty liver disease and diabetes: From physiopathological interplay to diagnosis and treatment

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World Journal of Gastroenterology 2014年第26期20卷 8377-8392页

作者： Nathalie C Leite Cristiane A Villela-Nogueira Claudia R L Cardoso Gil F Salles Internal Medicine department University Hospital Clementino Fraga FilhoSchool of MedicineUniversidade Federal do Rio de Janeiro

Non-alcoholic fatty liver disease(NAFLD)is highly prevalent in patients with diabetes mellitus and increasing evidence suggests that patients with type 2diabetes are at a particularly high risk for developing the progressive forms of NAFLD,non-alcoholic steatohepatitis and associated advanced liver ***,diabetes is an independent risk factor for NAFLD progression,and for hepatocellular carcinoma development and liver-related mortality in prospective ***,patients with NAFLD have an elevated prevalence of *** studies have shown that NAFLD presence predicts the development of type2 *** and NAFLD have mutual pathogenetic mechanisms and it is possible that genetic and environmental factors interact with metabolic derangements to accelerate NAFLD progression in diabetic *** diagnosis of the more advanced stages of NAFLD in diabetic patients shares the same challenges as in non-diabetic patients and it includes imaging and serological methods,although histopathological evaluation is still considered the gold standard diagnostic *** effective established treatment is not yet available for patients with steatohepatitis and fibrosis and randomized clinical trials including only diabetic patients are *** sought to outline the published data including epidemiology,pathogenesis,diagnosis and treatment of NAFLD in diabetic patients,in order to better understand the interplay between these two prevalent diseases and identify the gaps that still need to be fulfilled in the management of NAFLD in patients with diabetes mellitus.

关键词： Non-alcoholic fatty liver disease Diabetes mellitus Pathogenesis Diagnosis Treatment

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