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Photocatalytic degradation of the diazo dye naphthol blue black in water using MWCNT/Gd,N,S-TiO_2 nanocomposites under simulated solar light

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Journal of Environmental Sciences 2015年第7期27卷 219-228页

作者： Gcina Mamba xavier Yangkou Mbianda Ajay Kumar Mishra Department of Applied Chemistry University of Johannesburg Faculty of Science DST-NRF Centre of Excellence in Strong Materials School of Physics University of the Witwatersrand Nanotechnology and Water Sustainability Unit College of Engineering Science and Technology University of South Africa Florida Campus

A simple sol-gel method was employed to prepare gadolinium, nitrogen and sulphur tridoped titania decorated on oxidised multiwalled carbon nanotubes（MWCNT/Gd,N,S-Ti O2）, using titanium（IV） butoxide and thiourea as titanium and nitrogen and sulphur source, respectively. Samples of varying gadolinium loadings（0.2%, 0.6%, 1.0% and3.0% Gd3＋） relative to titania were prepared to investigate the effect of gadolinium loading and the amounts of carbon nanotubes, nitrogen and sulphur were kept constant for all the samples. Furthermore, the prepared nanocomposites were evaluated for the degradation of naphthol blue black（NBB） in water under simulated solar light irradiation. Higher degradation efficiency（95.7%） was recorded for the MWCNT/Gd,N,S-Ti O2（0.6% Gd）nanocomposites. The higher photocatalytic activity is attributed to the combined effect of improved visible light absorption and charge separation due to the synergistic effect of Gd,MWCNTs, N, S and Ti O2. Total organic carbon（TOC） analysis revealed a higher degree of complete mineralisation of naphthol blue black（78.0% TOC removal） which minimises the possible formation of toxic degradation by-products such as the aromatic amines. The MWCNT/Gd,N,S-Ti O2（0.6% Gd） was fairly stable and could be re-used for five times,reaching a maximum degradation efficiency of 91.8% after the five cycles.

关键词： Gadolinium MWCNTs NBB Simulated solar light Tridoped titania

Volumetric Vector-Based Representation for Indirect Illumination Caching

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Journal of Computer Science & Technology 2010年第5期25卷 925-932页

作者： Romain Pacanowski xavier Granier Christophe Schlick Pierre Poulin CEA-CESTA BP2 Le Barp33114France ACM INRIA Bordeaux Sud-Ouest/LaBRI-Bordeaux University Talence33405France State Key Lab of CAD&CG Zhejiang University LIGUM Dept.I.R.O.Universite de MontrealMontreal QCH3C 3J7Canada

This paper introduces a caching technique based on a volumetric representation that captures low-frequency indirect *** structure is intended for efficient storage and manipulation of *** is based on a 3D grid that stores a fixed set of irradiance *** preprocessing,this representation can be built using almost any existing global illumination *** rendering,the indirect illumination within a voxel is interpolated from its associated irradiance vectors,and is used as additional local light *** with other techniques,the 3D vector-based representation of our technique offers increased robustness against local geometric variations of a *** thus demonstrate that it may be employed as an efficient and high-quality caching data structure for bidirectional rendering techniques such as particle tracing or photon mapping.

关键词： caching for global illumination photon mapping particle tracing

Implicit large eddy simulation of unsteady cloud cavitation around a plane-convex hydrofoil

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Journal of Hydrodynamics 2015年第6期27卷 815-823页

作者： HIDALGO Victor 罗先武 ESCALER xavier 季斌 AGUINAGA Alvaro Beijing Key Laboratory of CO2 Utilization and Reduction Technology Tsinghua University CDIF Universitat Politècnica de Catalunya School of Power and Mechanical Engineering Wuhan University Mechanical Engineering Department Escuela Politecnica Nacional University

The present paper focuses on the erosive cavitation behavior around a plane convex hydrofoil. The Zwart-Gerber-Belamri cavitation model is implemented in a library form to be used with the OpenFOAM. The implicit large eddy simulation （ILES） is app- lied to analyze the three-dimensional unsteady cavitating flow around a plane convex hydrofoil. The numerical results in the cases under the hydrodynamic conditions, which were experimentally tested at the high speed cavitation tunnel of the l^cole Polytechnique F6d＆ale de Lausanne （EPFL）, clearly show the sheet cavitation development, the shedding and the collapse of vapor clouds. It is noted that the cavitation evolutions including the maximum vapor length, the detachment and the oscillation frequency, are captured fairly well. Furthermore, the pressure pulses due to the cavitation development as well as the complex vortex structures are reasona- bly well predicted. Consequently, it may be concluded that the present numerical method can be used to investigate the unsteady cavitation around hydrofoils with a satisfactory accuracy.

关键词： implicit large eddy simulation (ILES) unsteady partial cavitation Zwart-Gerber-Belamri cavitation model OpenFOAM,Q - criterion

Quantum Transport Properties of Chemically Functionalized Long Semiconducting Carbon Nanotubes

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Nano Research 2010年第4期3卷 288-295页

作者： Alejandro Lopez-Bezanilla xavier Blase Stephan Roche Commissariat a l’Energie Atomique 38054 Grenoble CedexFrance Institut Néel CNRS and UniversitéJoseph FourierB.P.16638042 Grenoble Cedex 09France CIN2(CSIC-ICN)Barcelona Campus UABE-08193 BellaterraSpain

We present a first-principles study of the electronic transport properties of micrometer long semiconducting carbon nanotubes randomly covered with carbene functional groups. Whereas prior studies suggested that metallic tubes are hardly affected by such addends, we show here that the conductance of semiconducting tubes with standard diameter is, on the contrary, severely damaged. The configurational-averaged conductance as a function of tube diameter, with a coverage of up to one hundred molecules, is extracted. Our results indicate that the search for a conductance-preserving covalent functionalization route remains a challenging issue.

关键词： Nanotubes functionalization carbene electronic transport

Ionic Species Affect the Self-Propulsion of Urease-Powered Micromotors

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Research 2020年第1期2020卷 349-362页

作者： xavier Arque xavier Andres Rafael Mestre Bernard Ciraulo Jaime Ortega Arroyo Romain Quidant Tania Patino Samuel Sanchez Institute for Bioengineering of Catalonia(IBEC) The Barcelona Institute of Science and Technology(BIST)Baldiri i Reixac 10-1208028 BarcelonaSpain Institute of Photonic Sciences(ICFO) The Barcelona Institute of Science and TechnologyCarl Friedrich Gauss 308860 CastelldefelsBarcelonaSpain InstitucióCatalana de Recerca i Estudis Avançats(ICREA) Pg.Lluís Companys 2308010 BarcelonaSpain Chemistry Department University of RomeTor VergataVia della Ricerca Scientifica00133 RomeItaly

Enzyme-powered motors self-propel through the catalysis of in situ bioavailable fuels,which makes them excellent candidates for biomedical ***,fundamental issues like their motion in biological fluids and the understanding of the propulsion mechanism are critical aspects to be tackled before a future application in ***,we investigated the physicochemical effects of ionic species on the self-propulsion of urease-powered *** showed that the presence of PBS,NaOH,NaCl,and HEPES reduced self-propulsion of urease-powered micromotors pointing towards iondependent mechanisms of *** studied the 3D motion of urease micromotors using digital holographic microscopy to rule out any motor-surface interaction as the cause of motion decay when salts are present in the *** order to protect and minimize the negative effect of ionic species on micromotors’performance,we coated the motors with methoxypolyethylene glycol amine(mPEG)showing higher speed compared to noncoated motors at intermediate ionic *** results provide new insights into the mechanism of urease-powered micromotors,study the effect of ionic media,and contribute with potential solutions to mitigate the reduction of mobility of enzyme-powered micromotors.

关键词： holographic salts catalysis

Outlook on the neuroprotective effect of estrogen

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Neural Regeneration Research 2017年第11期12卷 1799-1800页

作者： xavier d’anglemont de tassigny instituto de biomedicina de sevilla(ibis) departamento de fisiología médica y biofísicahospital universitario virgen del rocío/csic/universidad de sevillasevillaspain centro de investigación biomédica en red sobre enfermedades neurodegenerativas(ciberned) Madridspain

Epidemiologic studies often consider gender differences in a particular pathology, and constantly observe variations between men and wom- en. Indeed, a remarkable sexual dimorphism exists in the epidemiology of neurological conditions and brain diseases. Physiologically, males and females differ by their levels of circulating hormones that drive sexual behavioral, as well as endocrine functions. Estrogen is the pri- mary female sex hormonal group that enwraps estradiol, estrone and estriol, and which are the major naturally occurring hormones preva- lent in women. Their role in the reproductive function has long been established, although the ubiquitous expression of its receptors （alpha, beta and G protein-coupled, GPR30） presumes a broader spectrum of action. This short review will summarize the current knowledge in estrogen therapy with particular focus on some of the recent work that might lead to new neuroprotective treatments.

关键词： the neuroprotective effect estrogen

Cytomegalovirus and ulcerative colitis:Place of antiviraltherapy

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World Journal of Gastroenterology 2016年第6期22卷 2030-2045页

作者： Sylvie Pillet Bruno Pozzetto xavier Roblin Groupe Immunitédes Muqueuses et Agents Pathogènes(GIMAP)-EA3064 Faculty of Medicine of Saint-EtienneUniversity of Lyon69365 Lyon Cedex 7France Laboratory of Infectious Agents and Hygiene University Hospital of Saint-Etienne42025 Saint-Etienne Cedex 2France Department of Gastroenterology University Hospital of Saint-Etienne42025 Saint-Etienne Cedex 2France

The link between cytomegalovirus(CMV) infection and inflammatory bowel diseases remains an important subject of debate. CMV infection is frequent in ulcerative colitis(UC) and has been shown to be potentially harmful. CMV reactivation needs to be diagnosed using methods that include in situ detection of viral markers by immunohistochemistry or by nucleic acid amplification techniques. Determination of the density of infection using quantitative tools(numbers of infected cells or copies of the genome) is particularly important. Although CMV reactivation can be considered as an innocent bystander in active flareups of refractory UC, an increasing number of studies suggest a deleterious role of CMV in this situation. The presence of colonic CMV infection is possibly linked to a decreased response to steroids and other immunosuppressive agents. Some treatments, notably steroids and cyclosporine A, have been shown to favor CMV reactivation, which seems not to be the case for therapies using anti-tumor necrosis factor drugs. According to these findings, in flare-ups of refractory UC, it is now recommended to look for the presence of CMV reactivation by using quantitative tools in colonic biopsies and to treat them with ganciclovir in cases of high viral load or severe disease.

关键词： Human cytomegalovirus Ulcerative colitis Inflammatory bowel disease Ganciclovir Viral load Flare-up Inflammation Intestinal mucosa Quantitativepolymerase chain reaction

A GIS-based method for the selection of the location of residence

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Geo-Spatial Information Science 2012年第1期15卷 61-66页

作者： xavier ALBACETE Kari PASANEN Mikko KOLEHMAINEN Department of Environmental Science Research Group of Environmental InformaticsUniversity of Eastern FinlandYliopistoranta 1 EP.O.Box 162770211 KuopioFinland

Homebuyers are usually interested in both the accessibility of services and the quality of the local environment,and real estate agents frequently offer some web-based systems for home *** is however hardly any information about the quality of local living environment in those web-based *** purpose of this study was to develop a method for homebuyers,adaptable to the environmental variables of interest to homebuyers when selecting a home *** this paper,a multicriteria spatial analysis method is proposed and demonstrated for the homebuyers’selection process,using data from the City of Kuopio,*** spatial variables are applied,including environmental and service factors in the home searching process.A geographical information system(GIS)is used for creating maps for decision variables and mapping suitable *** method for ranking alternative dwellings is based on the difference between levels of the decision variables for each dwelling and the target levels given by the *** method presented in this paper is adaptable to other geographical and social *** decision analysis tool will be useful for both customers and real estate agents,and can also be used for city planning as a participatory-GIS(P-GIS)*** introduces new possibilities in the home selection *** availability of spatial data on the living environment in the webbased services for homebuyers is likely to have effects on customers’requirements and house markets,and also promote better spatial city organization in the long run.

关键词： home selection real estate market living environment GIS

CONVERGENCE OF NUMERICAL SCHEMES FOR A CONSERVATION EQUATION WITH CONVECTION AND DEGENERATE DIFFUSION

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Journal of Computational Mathematics 2021年第3期39卷 428-452页

作者： R.Eymard C.Guichard xavier Lhebrard Universite Gustave Eiffel Laboratoire d'nalyse et de Mathematiques Appliquees(UMR 8050)UGEUPECCNRSF-77454Mame-la-ValleeFrance Sorbonne Universite Universite Paris-Diderot SPCCNRSInriaLaboratoire Jacques-Louis Lionsequipe ANGEF-75005 Paris Ecole Normale Superieure de Rennes France

The approximation of problems with linear convection and degenerate nonlinear difFusion,which arise in the framework of the transport of energy in porous media with thermodynamic transitions,is done usingθ-scheme based on the centred gradient discretisation *** convergence of the numerical scheme is proved,although the test functions which can be chosen are restricted by the weak regularity hypotheses on the convection field,owing to the application of a discrete Gronwall lemma and a general result for the time translate in the gradient discretisation *** numerical examples,using both the Control Volume Finite Element method and the Vertex Approximate Gradient scheme,show the role ofθfor stabilising the scheme.

关键词： Linear convection Degenerate diffusion Gradient discretisation method θ-scheme