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Defence Technology（防务技术） 2024年第5期35卷 47-59页

作者： alexandre Riot Enrico Panettieri Antonio Cosculluela Marco Montemurro Universite de Bordeaux Arts et Metiers Institute of TechnologyCNRSINRABordeaux INPHESAM UniversiteI2M UMR 5295F-33405 TalenceFrance French Atomic Energy Commission Route des GargailsCedexF-33114Le BarpFrance

Modern additive manufacturing processes enable fabricating architected cellular materials of complex shape,which can be used for different *** them,lattice structures are increasingly used in applications requiring a compromise among lightness and suited mechanical properties,like improved energy absorption capacity and specific stiffness-to-weight and strength-to-weight ratios.A dedicated modeling strategy to assess the energy absorption capacity of lattice structures under uni-axial compression loading is presented in this *** numerical model is developed in a non-linear framework accounting for the strain rate effect on the mechanical responses of the lattice *** geometries,i.e.,cubic body centered cell,octet cell,rhombic-dodecahedron and truncated cuboctahedron 2+,are ***,the influence of the relative density of the representative volume element of each geometry,the strain-rate dependency of the bulk material and of the presence of the manufacturing process-induced geometrical imperfections on the energy absorption capacity of the lattice structure is *** main outcome of this study points out the importance of correctly integrating geometrical imperfections into the modeling strategy when shock absorption applications are aimed for.

关键词： Lattice structures Architected cellular materials Dynamic simulation Energy absorption Geometrical imperfection Additive manufacturing

Detailing the Structure of Liquid THF Based on an EPSR Study

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Computational Chemistry 2015年第1期3卷 1-7页

作者： alexandre borges Joao M.M.Cordeiro Department of Physics and Chemistry Sao Paulo State UniversityIlha SolteiraBrazil

The structure of pure liquid tetrahydrofuran (THF) has been investigated via Monte Carlo simulations in the wake of a previous Empirical Potential Structure Refinement (EPSR) study on that liquid (Bowron, D.T.;Finney, J.L.;Soper, A.K. (2006) J. Am. Chem. Soc., 128, 5119). The molecules are allatoms rigid structures and the intermolecular potential used is described for the classical 6-12 Lennard-Jones plus Coulomb in the NPT ensemble at 1 atm and 25°C. THF is a poorly structured liquid. Typical preferred orientation of molecules has been explored and calculations shown different types of molecular pairs exist concurrently in the liquid. The geometry of those pairs was deeply investigated and its influence in the liquid structure discussed. The lack of molecular organization in the liquid is closely related to the existence of that diversity of molecular pairs. Its geometry changes from antiparallel up to T-like depending on the distance between the molecules in the pairs.

关键词： Monte Carlo Simulations Tetrahydrofuran Liquid Structure

The impact of heterogeneity and pore network characteristics on single and multi-phase fluid propagation in complex porous media:An X-ray computed tomography study

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Petroleum Science 2024年第3期21卷 1719-1738页

作者： Shohreh Iraji Tales Rodrigues De Almeida Eddy Ruidiaz Munoz Mateus Basso alexandre Campane Vidal Department of Mechanical Engineering(FEM) State University of Campinas(UNICAMP)CampinasSP13083-860Brazil Department of Geology and Natural Resources Geosciences Institute(IG)State University of Campinas(UNICAMP)CampinasSP.13083-855.Brazil LRAP/COPPE/COPPETEC/UFRJ Rua Moniz Aragao 360Bloco 4 Cidade UniversitariaRio de Janeiro21941-594Brazil Center of Energy and Petroleum Studies(CEPETRO) State University of Campinas(UNICAMP)CampinasSP13083-896Brazil

This study investigates the impact of pore network characteristics on fluid flow through complex and heterogeneous porous media,providing insights into the factors affecting fluid propagation in such ***,high-resolution or micro X-ray computed tomography(CT)imaging techniques were utilized to examine outcrop stromatolite samples of the Lagoa Salgada,considered flow analogous to the Brazilian Pre-salt carbonate *** petrophysical results comprised two distinct stromatolite depositional facies,the columnar and the fine-grained *** generating pore network model(PNM),the study quantified the relationship between key features of the porous system,including pore and throat radius,throat length,coordination number,shape factor,and pore *** study found that the less dense pore network of the columnar sample is typically characterized by larger pores and wider and longer throats but with a weaker connection of throats to *** facies exhibited less variability in the radius of the pores and throats in comparison to throat ***,a series of core flooding experiments coupled with medical CT scanning was designed and conducted in the plug samples to assess flow propagation and saturation *** study revealed that the heterogeneity and presence of disconnected or dead-end pores significantly impacted the flow patterns and ***-phase flow patterns and oil saturation distribution reveal a preferential and heterogeneous displacement that mainly swept displaced fluid in some regions of plugs and bypassed it in *** relation between saturation profiles,porosity profiles,and the number of fluid flow patterns for the samples was *** for the columnar plug sample was the enhancement in recovery factor after shifting to lower salinity water injection(SB)observed.

关键词： Pore network model Heterogeneous porous media Flow patterns Dead-end pores

Effects of Andrade and Burgers rheologies on glacial isostatic adjustment modeling in Antarctica

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Geodesy and Geodynamics 2024年第5期 429-440页

作者： alexandre Boughanemi Anthony Mémin Université C?te d'Azur CNRS Observatoire de la C?te d'Azur IRD

Variations in ice mass deform the Earth and modify its gravity field, a process known as Glacial Isostatic Adjustment(GIA). GIA in Antarctica remains poorly constrained due to the cumulative effect of past and present ice-mass changes, the unknown history of the past ice-mass change, and the uncertainties on the mechanical properties of the Earth. This paper investigates the effect of using Andrade and Burgers viscoelastic rheologies, rather than the commonly used Maxwell rheology, to model GIA-induced deformation in Antarctica. The Love number and Green's function formalism are used to compute the radial surface displacements and the gravity changes induced by the past and present ice-mass changes. We consider an Earth model whose elastic properties and radial structure are averaged from the Preliminary Reference Earth Model and two viscosity profiles to account for the recently published results on the present ice-mass changes. Using the three rheological laws affects the temporal response of the Earth differently, leading to smaller discrepancies than those induced by the two viscosity structures. The differences are the largest between Maxwell and Burgers rheologies during the 100-1000 years following the beginning of the surface-mass change. Results show that using the Andrade and Burgers rheologies allows the Earth to respond on decennial to centennial time scales, up to 10 m more than Maxwell. Considering only the recent ice-mass changes, the deformation rates derived from Burgers and Andrade rheologies are several times larger than those estimated by Maxwell rheology.

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Assimilation of GOES-R Geostationary Lightning Mapper Flash Extent Density Data in GSI 3DVar, EnKF, and Hybrid En3DVar for the Analysis and Short-Term Forecast of a Supercell Storm Case

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Advances in Atmospheric Sciences 2024年第2期41卷 263-277页

作者： Rong KONG Ming XUE Edward R.MANSELL Chengsi LIU alexandre O.FIERRO Center for Analysis and Prediction of Storms Norman Oklahoma 73072U.S.A University of Oklahoma Norman Oklahoma 73072U.S.A NOAA/National Severe Storms Laboratory NormanOklahoma 73072U.S A.4Zentralanstalt für Meteorologie und Geodynamik Department of Forecasting Models-ZAMGVienna 1190Austria

Capabilities to assimilate Geostationary Operational Environmental Satellite “R-series ”(GOES-R) Geostationary Lightning Mapper(GLM) flash extent density(FED) data within the operational Gridpoint Statistical Interpolation ensemble Kalman filter(GSI-EnKF) framework were previously developed and tested with a mesoscale convective system(MCS) case. In this study, such capabilities are further developed to assimilate GOES GLM FED data within the GSI ensemble-variational(EnVar) hybrid data assimilation(DA) framework. The results of assimilating the GLM FED data using 3DVar, and pure En3DVar(PEn3DVar, using 100% ensemble covariance and no static covariance) are compared with those of EnKF/DfEnKF for a supercell storm case. The focus of this study is to validate the correctness and evaluate the performance of the new implementation rather than comparing the performance of FED DA among different DA schemes. Only the results of 3DVar and pEn3DVar are examined and compared with EnKF/DfEnKF. Assimilation of a single FED observation shows that the magnitude and horizontal extent of the analysis increments from PEn3DVar are generally larger than from EnKF, which is mainly caused by using different localization strategies in EnFK/DfEnKF and PEn3DVar as well as the integration limits of the graupel mass in the observation operator. Overall, the forecast performance of PEn3DVar is comparable to EnKF/DfEnKF, suggesting correct implementation.

关键词： GOES-R lightning data assimilation EnKF EnVar

Verification and Validation of High-Resolution Inviscid and Viscous Conical Nozzle Flows

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Communications on Applied Mathematics and Computation 2024年第1期6卷 533-549页

作者： Luciano K.Araki Rafael B.de R.borges Nicholas Dicati P.da Silva Chi-Wang Shu Department of Mechanical Engineering Federal University of ParanáCuritiba81531-980ParanáBrazil Mathematics and Statistics Institute Rio de Janeiro State UniversityRio de Janeiro20550-900Rio de JaneiroBrazil Department of Mechanical Engineering State University of MaringáMaringá87020-900ParanáBrazil Division of Applied Mathematics Brown UniversityProvidenceRI02912USA

Capturing elaborated flow structures and phenomena is required for well-solved numerical *** finite difference methods allow simple discretization of mesh and model ***,they need simpler meshes,e.g.,*** inverse Lax-Wendroff(ILW)procedure can handle complex geometries for rectangular ***-resolution and high-order methods can capture elaborated flow structures and *** also have strong mathematical and physical backgrounds,such as positivity-preserving,jump conditions,and wave propagation *** perceive an effort toward direct numerical simulation,for instance,regarding weighted essentially non-oscillatory(WENO)***,we propose to solve a challenging engineering application without turbulence *** aim to verify and validate recent high-resolution and high-order *** check the solver accuracy,we solved vortex and Couette ***,we solved inviscid and viscous nozzle flows for a conical *** employed the finite difference method,positivity-preserving Lax-Friedrichs splitting,high-resolution viscous terms discretization,fifth-order multi-resolution WENO,ILW,and third-order strong stability preserving *** showed the solver is high-order and captured elaborated flow structures and *** can see oblique shocks in both nozzle *** the viscous flow,we also captured a free-shock separation,recirculation,entrainment region,Mach disk,and the diamond-shaped pattern of nozzle flows.

关键词： High-resolution Compressible Navier-Stokes Free-shock separation Nozzle flow

Severe dengue in the intensive care unit

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Journal of Intensive Medicine 2024年第1期4卷 16-33页

作者： alexandre Mestre Tejo Debora Toshie Hamasaki Letícia Mattos Menezes Yeh-Li Ho Intensive Care Unit Department of Intensive Medicine of the Cancer Institute of the State of São PauloHospital das Clínicas da Faculdade de Medicina da Universidade de São PauloSão PauloBrazil Transfusion Medicine and Cell Therapy Department A.C.Camargo Cancer CenterSão PauloBrazil Intensive Care Unit of Infectious Disease Department Hospital das Clínicas da Faculdade de Medicina da Universidade de São PauloSão PauloBrazil

Dengue fever is considered the most prolific vector-borne disease in the world,with its transmission rate increasing more than eight times in the last two *** most cases present mild to moderate symptoms,5%of patients can develop severe *** the mechanisms are yet not fully comprehended,immune-mediated activation leading to excessive cytokine expression is suggested as a cause of the two main findings in critical patients:increased vascular permeability that may shock and thrombocytopenia,and coagulopathy that can induce *** risk factors of severe disease include previous infection by a different serotype,specific genotypes associated with more efficient replication,certain genetic polymorphisms,and comorbidities such as diabetes,obesity,and cardiovascular *** World Health Organization recommends careful monitoring and prompt hospitalization of patients with warning signs or propensity for severe disease to reduce *** review aims to update the diagnosis and management of patients with severe dengue in the intensive care unit.

关键词： Severe dengue Intensive care units Shock Pathogenesis Diagnosis Management

Investigation of pore geometry influence on fluid flow in heterogeneous porous media:A pore-scale study

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Energy Geoscience 2024年第1期5卷 72-88页

作者： Ramin Soltanmohammadi Shohreh Iraji Tales Rodrigues de Almeida Mateus Basso Eddy Ruidiaz Munoz alexandre Campane Vidal Ingram School of Engineering Texas State UniversitySan MarcosTX78666USA Department of Mechanical Engineering(FEM) State University of Campinas(UNICAMP)CampinasSP13083-855Brazil Department of Geology and Natural Resources Geosciences Institute(IG)State University of Campinas(UNICAMP)CampinasSP13083-855Brazil Center of Energy and Petroleum Study(CEPETRO) State University of Campinas(UNICAMP)CampinasSP13083-855Brazil

Brazilian pre-salt reservoirs are renowned for their intricate pore networks and vuggy nature,posing significant challenges in modeling and simulating fluid flow within these carbonate *** possessing excellent petrophysical properties,such as high porosity and permeability,these reservoirs typically exhibit a notably low recovery factor,sometimes falling below 10%.Previous research has indicated that various enhanced oil recovery(EOR)methods,such as water alternating gas(WAG),can substantially augment the recovery factor in pre-salt reservoirs,resulting in improvements of up to 20%.Nevertheless,the fluid flow mechanism within Brazilian carbonate reservoirs,characterized by complex pore geometry,remains *** study examines the behavior of fluid flow in a similar heterogeneous porous material,utilizing a plug sample obtained from a vugular segment of a Brazilian stromatolite outcrop,known to share analogies with certain pre-salt *** conducted single-phase and multi-phase core flooding experiments,complemented by medical-CT scanning,to generate flow streamlines and evaluate the efficiency of water ***,micro-CT scanning of the core sample was performed,and two cross-sections from horizontal and vertical plates were *** cross-sections were then employed as geometries in a numerical simulator,enabling us to investigate the impact of pore geometry on fluid *** of the pore-scale modeling and experimental data unveiled that the presence of dead-end pores and vugs results in a significant portion of the fluid remaining stagnant within these ***,the injected fluid exhibits channeling-like behavior,leading to rapid breakthrough and low areal swept ***,the numerical simulation results demonstrated that,irrespective of the size of the dead-end regions,the pressure variation within the dead-end vugs and pores is *** the stromatolite's favorable petrophysica

关键词： Pore-scale modeling Pore geometry Flow streamlines Computational modeling Digital rock analysis

Novel Brick Technology for Carbon Reduction Footprint in Steel Shop Linings

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China's Refractories 2024年第2期33卷 16-21页

作者： Carlos PAGLIOSA Leandro ROCHA Marcelo borges Celio CAVALCANTE RHI MAGNESITA Contagem32210-000Brazil

Clean steel encompasses a multitude of concepts that are based on fulfilling customer requirements and can be produced in many ways depending on the existing equipment and detailed customer demands.A common feature of all clean steel production is tight process control along with continuous *** meet an increasing demand for cold-rolled(CR)steel sheets of improved mechanical properties,and to cope with the change of the annealing process from a batch-type to a continuous process,it is necessary to establish a technique for making ultralow carbon(ULC)steel with a C-concentration lower than 20 ppm for the steelmaking process associated with a major challenge to guarantee the competitiveness with observance of environmental *** ladle lining plays an important role on the energy consumption during the production and the refractory lining design contributes to minimize thermal bath loss,carbon pick up and shell temperature.A new generation of unfired zero carbon refractories was developed with two specific approaches:(1)replacement of firing bricks reducing CO_(2) footprint and(2)replacement of carbon containing with performance *** can be used in working and safety linings with a unique microstructure with better heat scattering and similar thermomechanical *** work presents customers’performance compared to traditional products highlighting energy savings.

关键词： steel ladle zero carbon energy saving

Simulated rainfall in Brazil:An alternative for assesment of soil surface processes and an opportunity for technological development

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International Soil and Water Conservation Research 2024年第1期12卷 29-42页

作者： Camila Calazans da Silva Luz Wilk Sampaio de Almeida Adilson Pacheco de Souza Nivaldo Schultz Jamil alexandre Ayach Anache Daniel Fonseca de Carvalho Postgraduate Program in Agronomy-Soil Sciences Federal Rural University of Rio de JaneiroSeropédicaRJBrazil Agronomy Department Federal Institute of EducationScience and Technology of RondôniaAriquemesROBrazil Federal University of Mato Grosso SinopMTBrazil Federal Rural University of Rio de Janeiro SeropédicaRJBrazil Federal University of Mato Grosso do Sul Campo GrandeMSBrazil

Rainfall simulators(RS)have been used,above all,to evaluate hydrological processes related to soil water infiltration,surface runoff and soil *** allow repeatability of rain application with different precipitation intensities in field and/or laboratory conditions and should produce events with physical characteristics similar to natural *** this manuscript,we carried out a bibliometric and scientometric analysis of studies with simulated rainfall in Brazil to assess the temporal evolution of publications,the main topics addressed and the degree of technological development of the *** searched for the terms“rainfall simulator”OR“simulated rainfall”AND“Brazil”in the Scopus,Web of Science,SciELO and Google Scholar *** found 143 articles published in the last 37 years(1985-2022).Our findings indicate that the main research areas covered in papers are soil erosion(57.34%),soil water infiltration(24.47%),nutrient losses(9.8%)and RS development and calibration/assessment(8.39%).In recent years,the number of published papers in international high-impact factor journals has *** of the papers(49.65%)refer to studies carried out by institutions located in the south and southeast regions of ***,there is a large gap of studies on simulated rainfall in other regions of Brazil,where important biomes such as the Cerrado,Amazon,Caatinga,and their transitions are *** study informs research priorities on soil erosion under simulated rainfall and provides a bibliographic database that can assist in more detailed future analyses.

关键词： Rainfall simulator Soil and water losses Soil water infiltration Bibliometrics Scientific review