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An Immersed Method Based on Cut-Cells for the Simulation of 2D Incompressible Fluid Flows Past Solid Structures

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Computer Modeling in Engineering & Sciences 2019年第4期119卷 165-184页

作者： francois Bouchon Thierry Dubois Nicolas James Université Clermont Auvergne CNRSLMBPF-63000 CLERMONT-FERRANDFrance Laboratoire de Mathématiques et Applications UMR 7348 Universitéde PoitiersTéléport 2-B.P.30179Boulevard Marie et Pierre Curie86962 Futuroscope Chasseneuil CedexFrance

We present a cut-cell method for the simulation of 2D incompressible flows past *** consists in using the MAC scheme on cartesian grids and imposing Dirchlet boundary conditions for the velocity field on the boundary of solid structures following the Shortley-Weller *** order to ensure local conservation properties,viscous and convecting terms are discretized in a finite volume *** scheme is second order implicit in time for the linear part,the linear systems are solved by the use of the capacitance matrix method for non-moving *** results of flows around an impulsively started circular cylinder are presented which confirm the efficiency of the method,for Reynolds numbers 1000 and *** example of flows around a moving rigid body at Reynolds number 800 is also shown,a solver using the PETSc-Library has been prefered in this context to solve the linear systems.

关键词： Immersed boundary methods cutt-cell methods incompressible viscous flows

Implementation of a choline bis(trifluoromethylsulfonyl)imide aqueous electrolyte for low temperature EDLCs enabled by a cosolvent

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Journal of Energy Chemistry 2022年第7期31卷 84-94,I0004页

作者： Zhuanpei Wang francois Béguin Institute of Chemistry and Technical Electrochemistry Poznan University of TechnologyBerdychowo 460-965 PoznanPoland

We report a carbon/carbon capacitor based on micro/mesoporous carbon electrodes with cost-effective and eco-friendly aqueous choline bis(trifluoromethylsulfonyl)imide(Ch TFSI)electrolyte with a cosolvent enabling low-temperature operation down to-30℃.For this purpose,a Mg O-templated hierarchical carbon(MP98B)with an average mesopore diameter of 3.5 nm was prepared by pyrolysis of magnesium citrate hydrate at 900℃.To reach lower temperatures,the melting point and viscosity of the aqueous electrolyte were reduced by mixing water(W)with an organic solvent(methanol,M,or isopropanol,I)of high dielectric constant and low viscosity.5 mol kg^(-1)(5 m)Ch TFSI in an optimized volume fraction of cosolvent,M_(0.75)W_(0.25),and I_(0.75)W_(0.25),showed the highest conductivity;the higher conductivity in M_(0.75)W_(0.25)(22.8 and 3.1 m S cm^(-1) at 20 and-30℃,respectively)than in I_(0.75)W_(0.25)(8.5 and0.5 m S cm^(-1)at 20 and-30℃,respectively)is attributed to the lower viscosity of the M_(0.75)W_(0.25)*** electrochemical stability window(ESW)of 5 m Ch TFSI in M_(0.75)W_(0.25)and I_(0.75)W_(0.25)(1.6 V)on an MP98B electrode was determined by applying the ***,by adjusting the mass ratio of the two electrodes,a MP98B/MP98B capacitor using the 5 m electrolyte in M_(0.75)W_(0.25)could operate with a good life span up to 1.6 V while exhibiting a better charge propagation,greater specific capacitance,and higher specific energy than in I_(0.75)W_(0.25).

关键词： Carbon/carbon capacitor Choline bis(trifluoromethylsulfonyl)imide Low-temperature Aqueous electrolyte Cosolvent electrolyte Methanol Isopropanol

Skin Friction Gage for Measurements in Hypersonic Flow

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Journal of Thermal Science 2003年第1期12卷 44-50页

作者： francois Falempin Marat Goldfeld Roman Nestoulia EADS Aerospatiale Matra Missiles ChatillonInstitute of Theoretical and Applied Mechanics NovosibirskInstitute of Theoretical and Applied Mechanics Novosibirsk France Russia Russia

A description and results of tests of a new small-scale gage for direct measurement of skin friction force are presented in the *** gage design provides separated measurement of longitudinal and transversal component of friction *** of this scheme provides high sensitivity and necessary high-frequency response of the *** tests of the gage were carried out in a blow down wind tunnel at Mach numbers of 2 and 4 within the range of Reynolds numbers Rex from 0.8 to 5 million and in the hot-shot wind tunnel at Mach number 6 and Reynolds numbers Rex=2.5-10 *** measurements of skin friction were carried out on a flat plate and on a ramp beyond the shock *** with the direct measurement of friction in the blow down wind tunnel,the measurements of profiles of average velocities and mass flow rate pulsations were *** of measurement errors has shown that the friction gage permits to measure skin friction coefficient on a flat plate with mistake not more than 10%.

关键词： skin friction gage hypersonic flow scramjet.

Experimental investigation of control updating period monitoring in industrial PLC-based fast MPC： Application to the constrained control of a cryogenic refrigerator

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Control Theory and Technology 2017年第2期15卷 92-108页

作者： francois BONNE Mazen ALAMIR Patrick BONNAY Universite Grenoble Alpes INAC-SBT F-38000 Grenoble France CNRS Gipsa-lab Universite Grenoble Alpes F-3800 Grenoble France

In this paper, a complete industrial validation of a recently published scheme for on-line adaptation of the control updating period in model predictive control is proposed. The industrial process that serves in the validation is a cryogenic refrigerator that is used to cool the supra-conductors involved in particle accelerators or experimental nuclear reactors. Two recently predicted features are validated： the first states that it is sometimes better to use less efficient （per iteration） optimizer if the lack of efficiency is overmcompensated by an increase in the updating control frequency. The second is that for a given solver, it is worth monitoring the control updating period based on the on-line measured behavior of the cost function.

关键词： Fast MPC cryogenic refrigerators control updating period ODE-based optimization

Effects of a municipal effluent on the freshwater mussel Elliptio complanata following challenge with Vibrio anguillarum

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Journal of Environmental Sciences 2015年第11期27卷 91-99页

作者： Gagne francois Douville Melanie Fortier Marlene Fournier Michel Aquatic Contaminants Research Division Water Science and Technology INRS-Institut Armand-Frappier

The purpose of this study was to examine the cumulative effects of exposure to a pathogenic bacteria and municipal effluent in the freshwater mussel Elliptio complanata. Mussels were exposed to increasing concentrations of an ozone-treated effluent at 15°C for 7 days. A sub-group of mussels was inoculated with Vibrio anguillarum and exposed to the same conditions as *** the exposure period, mussels were collected to assess hemocyte count and viability,immunocompetence（phagocytosis and nitrite production）, oxidative stress/inflammation（cyclooxygenase and lipid peroxidation） and oxygen radical/xenobiotic scavenging activity（metallothioniens, glutathione S-transferase）. The results showed that mussels exposed to municipal effluent had increased hemocyte counts, phagocytosis, nitrites, lipid peroxidation and metallothioneins. In the inoculated mussels, the same responses were observed, in addition to cyclooxygenase and glutathione S-transferase activities. Multivariate analyses revealed that（1）the response pattern changed with effluent concentration, where increased responses observed at low effluent concentrations（〉10%, V/V） were attenuated at higher effluent concentrations,（2）the effluent produced more pronounced changes in lipid peroxidation, metallothionein and hemocyte viability, and（3） the simultaneous presence of V. anguillarum led to more important changes in hemocyte count and viability and nitrite levels. In conclusion, the presence of *** could alter the response of mussels to municipal effluent, which could lead to increased inflammation in mussels.

关键词： Elliptio complanata Immunocompetence Oxidative stress Inflammation Vibrio anguillarum

Niobium–tantalum oxide minerals in alluvial placer deposits from the Ngoura area,East-Cameroon

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Acta Geochimica 2021年第1期40卷 13-24页

作者： francois Ndong Bidzang Elise Sababa Tessontsap Teutsong Ore Processing Laboratory Institute of Geological and Mining ResearchP.O.Box 4110YaoundeCameroon Department of Earth Sciences University of Yaounde 1.P.O.Box 812YaoundeCameroon

This work presents a preliminary mineralogical characterization of Nb-Ta oxide minerals from alluvial placers located in the Ngoura area,eastern *** heavy minerals are characteristic of short hydromechanical transport and highlight the stability of Nb-Ta oxides during the weathering and ***-Ta mineralization in placer deposits from the Ngoura area may derive from local *** assemblage of Nb-Ta oxides in the studied placers consists of tapiolite-(Fe)and tantalite-(Mn).Tapiolite-(Fe)exhibits high concentrations in Ta2O5(78.07-80.46 wt%)and FeO(12.18-13.66 wt%)and plots within a narrow range of Ta*(0.900-0.933)and Mn*(0.037-0.119),which correspond to the ranges typically observed in tapiolite-(Fe)***-(Mn)shows Ta2O5 contents ranging from 62.17 to 69.45 wt%,Nb2O5 from 12.09 to 17.37 wt%,MnO from 7.63 to 12.49 wt%and FeO from 1.48 to 6.62 wt%.It is also characterized by a wider range of Mn*(0.538-0.891)and relatively homogeneous Ta/(Ta+Nb)(0.683-0.779)***,the studied Nb-Ta minerals exhibit oscillatory zoning characterized by bright Ta-rich zones alternating with dark Nb-rich *** oscillatory zoning is progressive in some minerals and the alternating bands may appear regular to wavy with gradual *** zoning in Nb-Ta oxides from the Ngoura placers is considered to be a primary magmatic feature and is tentatively explained as a result of magmas mixing,rapid cooling or degassing/decompression of the igneous *** geomorphology and the tropical humid climate of the eastern region offer suitable conditions for the deposition of alluvial ***,niobium-tantalum minerals from the Ngoura placers must have been sourced from the weathering and erosion of alkaline granites and pegmatites widespread in the study area.

关键词： Niobium Tantalum Tapiolite-(Fe) Tantalite-(Mn) Ngoura placer East Cameroon

Computation of Shock Profiles in Radiative Hydrodynamics

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Communications in Computational Physics 2009年第10期6卷 1118-1136页

作者： Jean-francois Coulombel Pauline Lafitte CNRS Laboratoire Paul Painleve and Project Team SIMPAF INRIA FutursUniversite Lille 1Cite Scientifique59655 VILLENEUVE D’ASCQ CedexFrance Laboratoire Paul Painleve and Project Team SIMPAF INRIA Futurs Universite Lille 1Cite Scientifique59655 VILLENEUVE D’ASCQ CedexFrance

This article is devoted to the construction of a numerical scheme to solve the equations of radiative *** use this numerical procedure to compute shock profiles and illustrate some earlier theoretical results about their smoothness and monotonicity *** first consider a scalar toy model,then we extend our analysis to a more realistic system for the radiative hydrodynamics that couples the Euler equations and an elliptic equation.

关键词： Radiative transfer shock profiles Euler equations numerical profiles

The"Cultural Archipelago"of Urban Representation in Contemporary Brazilian Novels

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Journal of Foreign Languages and Cultures 2021年第2期5卷 103-112,156页

作者： francois Weigel Federal University of Rio Grande do Norte

The dialectic of localism and cosmopolitanism,with the opposition between nationalists and cosmopolitans,since independence and perhaps even before,is an element that structured the spiritual life and the literature of a country such as Brazil,as it was pointed out by Antonio *** dialectic in a globalized country which had been transformed by an extremely rapid urbanization,nowadays is perhaps stronger than *** could be seen in contemporary literature,on the level of the imaginary but also on the level of the representation of cities such as Manaus in the north of the country(Relato de um certo Oriente,by Milton Hatoum),Recife in the northeast(Estive la fora,by Ronaldo Correia de Brito),or Brasilia in the central west(Cidade Livre,by Joao Almino).Through these three novels,this essay aims to analyze how a few years after the end of the dictatorship,at a time marked by important changes in Brazilian society,the fiction grasps the articulation between local specificities and the“globalized”*** that extent,the reading of many urban contemporary fictions will build a kind of mosaic of Brazil and its cultural varieties,through the prism of the city.

关键词： contemporary novel Brazilian literature urban representation

Mapping of groundwater potential zones in the drought-prone areas of south Madagascar using geospatial techniques

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Geoscience Frontiers 2020年第4期11卷 1403-1413页

作者： Charles Serele Ana Perez-Hoyos francois Kayitakire UNICEF Madagascar European Commission Joint Research Centre(JRC)Via E.Fermi 2749I-21027IspraVAItaly

The southern regions of Madagascar have the country’s lowest water supply coverage and are highly vulnerable to *** to potable drinking water is a major challenge for the local *** droughts lead to annual emergency appeals to save the lives of acute malnourished ***’s response consisting in providing potable drinking water through the drilling of boreholes has been challenged by the complex hydrogeology,the low yield of boreholes and high-level salinity of water,the lack of reliable groundwater data and the weak capacity of the drilling *** constraints result in a high rate of drilling *** improve drilling success and provide more potable drinking water to local communities,it is vital to undertake reliable groundwater *** Madagascar and the European Union delegation in Madagascar collaborated on the use of satellite imagery to improve sector knowledge and access to safe and clean water for local communities in southern *** methodology relies on produce thematic layers of groundwater potential ***,these thematic layers were overlaid with ground-based hydrogeological data to map the groundwater potential zones(GWP) and identify the most suitable sites for borehole siting and *** of this study are very encouraging,and the integrated approach used has proven its applicability in mapping groundwater potential areas in the eight drought-affected areas of south *** groundwater potential zone map is being used by UNICEF and partners to plan water supply projects and identify the best sites for positioning new boreholes and reduce the likelihood of drilling ***,the project developed a database of groundwater resources,which will improve knowledge of the regional hydrogeological context and strengthen the capacity of the water *** learnt from this study show that an integration of the groundwater potential zone map with demographics a

关键词： Groundwater potential zones(GWP) Overlay analysis Remote sensing Geographic information system(GIS) South Madagascar