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First-wave COVID-19 daily cases obey gamma law

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Infectious Disease Modelling 2022年第2期7卷 64-74页

作者： Jean Duchesne Olivier A.Coubard Agrocampus Ouest 2 rue Andre Le Notre49000AngersFrance The Neuropsychological Laboratory CNS-Fed240 rue de Rivoli75001ParisFrance

Modelling how a pandemic is spreading over time is a challenging *** new coronavirus disease called COVID-19 does not escape this rule as it has embraced over two hundred *** for previous pandemics,several studies have attempted to model the occurrence of cases caused by ***,no study has succeeded in accurately modelling the impact of the infectious *** we show that COVID-19 daily case distribution in humans obeys a Gamma law,which two new parameters can describe without any *** the Gamma law has been exploited for nearly two centuries to describe the statistical distribution of spatial or temporal quantities,the goodness-of-fit rationale using two or three parameters has remained *** new Gamma law approach we demonstrate here emerges from actual data and sheds light on the underlying mechanisms of the observed *** finding has promising applicability in the epidemiological domain and in all disciplines involving branching systems,for which our Gamma law approach may bring a solution to hitherto unsolved problems.

关键词： COVID-19 Epidemiology Gamma law Humans Statistical physics

Biodegradation of polycyclic aromatic hydrocarbons(PAHs)by fungal enzymes:A review

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Journal of Environmental Sciences 2017年第1期29卷 52-74页

作者： Tayssir Kadri Tarek Rouissi Satinder Kaur Brar Maximiliano Cledon Saurabhjyoti Sarma Mausam Verma INRS-ETE Universite du Quebec490 Rue de la CouronneQuebecQC G1K 9A9Canada CO2 Solutions Inc. 2300rue Jean-PerrinQuebecQC G2C 1T9Canada

Polycyclic aromatic hydrocarbons（PAHs） are a large group of *** represent an important concern due to their widespread distribution in the environment,their resistance to biodegradation,their potential to bioaccumulate and their harmful *** pilot treatments have been implemented to prevent economic consequences and deterioration of soil and water *** a promising option,fungal enzymes are regarded as a powerful choice for degradation of *** chrysosporium,Pleurotus ostreatus and Bjerkandera adusta are most commonly used for the degradation of such compounds due to their production of ligninolytic enzymes such as lignin peroxidase,manganese peroxidase and *** rate of biodegradation depends on many culture conditions,such as temperature,oxygen,accessibility of nutrients and agitated or shallow ***,the addition of biosurfactants can strongly modify the enzyme *** removal of PAHs is dependent on the ionization *** study of the kinetics is not completely comprehended,and it becomes more challenging when fungi are applied for *** studies in soil are much more complicated than liquid cultures because of the heterogeneity of soil,thus,many factors should be considered when studying soil bioremediation,such as desorption and bioavailability of *** degradation pathways can be *** peroxidases are heme-containing enzymes having common catalytic *** molecule of hydrogen peroxide oxidizes the resting enzyme withdrawing two ***,the peroxidase is reduced back in two steps of one electron *** are copper-containing *** reduce molecular oxygen to water and oxidize phenolic compounds.

关键词： Polycyclic aromatic hydrocarbons (PAHs) Biodegradation Fungi Enzymes

Production of metallic nanopowders(Mg,Al)by solar carbothermal reduction of their oxides at low pressure

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Journal of Magnesium and Alloys 2016年第2期4卷 140-150页

作者： J.Puig M.Balat-Pichelin promes-cnrs laboratory 7 rue du four solaire66120 font-romeu odeillofrance

The carbothermal reduction of MgO and Al_(2)O_(3) in argon flow at low pressure allows to lower the onset temperature of metal vapor *** calculations indicate that metal formation begins at 1400 and 1700 K for a primary vacuum(1000 Pa),respectively,for Mg and *** the experimental section,concentrated solar energy was used for the process heating in order to favor energy *** products of the reaction between MgO or Al_(2)O_(3) and 2 varieties of carbon(graphite,carbon black)in flowing argon atmosphere at a total pressure of around 1000 to 1600 Pa were studied using X-ray diffraction,and microstructure observations revealed the formation of metallic nanopowders with some *** conversions close to 45 wt%and 52 wt%,respectively,for Mg and Al,were *** low conversion yield of the carbothermal reduction of MgO can be attributed to a backward reaction reforming MgO powder and to a sintering process between oxide particles at high *** production challenge is to avoid formation of undesired by-products:Al_(2)O,Al_(4)C_(3) and *** and weaknesses of the used process are described and some improvements are proposed to increase metallic yields.

关键词： Carbothermal reduction Thermodynamics Concentrated solar energy XRD Metallic nanopowders

Characterisation of the granular dynamics at the interface between a pipe and a granular flow in a rotating drum

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Particuology 2024年第3期86卷 117-125页

作者： Francois Rioual Paule Emmanuelle Eva Gbehe Research Unit FRISE National Research Institute for Agriculture Food and the Environment1 Rue Pierre Gilles De Gennes92160AntonyFrance

A new mobile bed heat exchanger is presented in this work which is composed of a flowing granular material in a rotating drum and a cylindrical pipe with potential interest in different energy applications as cooling,heating or heat recovery *** optimal design of the device requires a characterisation of the phenomena involved at the interface between the granular flow and the *** process is modelled by the discrete element method and a global classification of the flow patterns around the pipe is presented with respect to the three main control parameters of the problem:the Froude number,the diameter ratio and the relative filling height of the *** second part is devoted to the characterisation of the structure of the flow at the interface(velocity field,density field)in particular in a so-called Biflow regime where granular motion occurs above as well as below the pipe which is favourable to transfer by convection.A typical behavior at the interface with the pipe consists of a zone I with high velocities of particles at the top of the pipe,a second zone with quasistatic particles or low velocity particles at the front and at the bottom of the pipe and a last zone ll of depletion of particles at the back of the *** Froude number has a limited effect on the features of this structure on the first layer in the range of Froude numbers considered whereas the relative height is a more determinant parameter to control the relative magnitude of velocities in zone I and zone Il as well as the extent of the depletion *** first hydrodynamical characterisation can shed light on the dynamical regimes with improved transfer between the particles and the pipe boundary.

关键词： Granular flow Transfer Heat exchange Mobile bed Boundary condition

Pressureless sintering behavior and properties of Ag-SnO_2

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Rare Metals 2019年第1期38卷 35-41页

作者： Henri Desplats Elodie Brisson Philippe Rogeon Patrick Carré Alexandre Bonhomme Department of Materials Engineering IRDL FRE CNRS 3744University of South Brittany Schneider Electric-Electropole 31 rue Pierre Mendes France

In this study, the results of measurements on pressureless sintering behavior of Ag-SnO_2(88%wt Ag,12%wt SnO_2) pellets were reported. Dilatometric measurements, relative densities, hardness values, rupture transverse strength and electrical conductivities function of sintering temperatures were presented. A constant thermal expansion coefficient was determined, and a threshold temperature of densification(T_d) was exhibited. Sintering kinetics were reported for different temperatures. Hardness values were measured, and no increase in hardness is found under Td. Three-points bending tests were used to determine the transverse rupture strength whose evolution appears importantly well under Td. In the same manner, the increase in initial electrical conductivities begins well under Td. Under the threshold temperature, the relative increase in electrical conductivity is found to be independent of initial density of green compact pellets. This work highlights different evolutions in function of sintering temperature for the electrical conductivity and transverse rupture strength on the one hand, and for the densification and hardness on the other hand.

关键词： Ag-SnO2 Pressureless sintering Dilatometry Mechanical properties Electrical conductivity

Compressive behavior and energy absorption of metal porous polymer composite with interpenetrating network structure

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中国有色金属学会会刊：英文版 2006年第B2期16卷 439-443页

作者： LIU Yu GONG Xiao-lu Institut Charles Delaunay CNRS FRE 2848 LASMIS UTT 12 rue Marie Curie BP 2060 10010 Troyes France

Interpenetrating phase composites (IPCs) are a new class of composite materials with improved combinations of mechanical and physical properties. This study was performed on a new type of IPC called metal porous polymer composite (MPPC) with an interpenetrating network structure. Aluminum-polypropylene (AI-PE) and Aluminum-epoxy resin (Al-Ep) composites were produced by infiltrating the polymer in the aluminum foam. The composite microstructures were characterized using SEM observation. The compressive behavior and energy absorption characteristics of MPPC were investigated and compared with the aluminum foams. The compressive modulus of composite was compared with the VOIGT-REUSS bounds and HASHIN-SHTRIKMAN (H-S) bounds models. The experimental modulus of compressive tests falls well within the theoretical models.

关键词：金属多孔聚合物复合物互穿网络结构压缩行为能量吸收 MPPC复合物

Effect of insoluble materials on the volumetric behavior of rock salt

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第1期13卷 84-97页

作者： Mejda Azabou Ahmed Rouabhi Laura Blanco-Martìn MINES ParisTech PSL Research UniversityCentre de Géosciences35 rue St HonoréFontainebleau77300France

This paper focuses on the presence of nodules of insoluble materials within salt specimens,and their effect on the volumetric strain measurements and the dilatancy *** analyzed experimental results of over 120 conventional triaxial compression tests,and found that in 20%of the cases,the volumetric strain measurements were *** also noted that the natural variability of the specimens can lead to a non-negligible data scattering in the volumetric strain measurements when different specimens are subjected to the same *** is expected given the small magnitude of those strains,but it occasionally implies that the corresponding specimens are not representative of the volumetric behavior of the studied *** order to understand these results,we numerically investigated salt specimens modeled as halite matrices with inclusions of *** of triaxial compression tests on these structures proved that such heterogeneities can induce dilatancy,and their presence can lead to the appearance of tensile zones which is physically translated into a micro-cracking *** modeling approach is validated as the patterns displayed in the numerical results are identical to that in the *** was then employed to explain the observed irregularities in experimental *** studied the natural variability effect as well and proposed a methodology to overcome the issue of specimen representativity from both deviatoric and volumetric perspectives.

关键词： Rock salt Dilatancy Material heterogeneity Natural variability Triaxial tests Virtual laboratory

Detection of Impending Vehicle Rollover with Road Bank Angle Consideration Using a Robust Fuzzy Observer

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International Journal of Automation and computing 2015年第1期12卷 93-101页

作者： Hamid Dahmani Mohammed Chadli Abdelhamid Rabhi Ahmed El Hajjaji University of Picardie Jules Verne-MIS Laboratory (EA4290) 33 rue Saint-Leu Amiens 80039 France

This article describes a method of vehicle dynamics estimation for impending rollover detection. We estimate vehicle dynamic states in presence of the road bank angle as a disturbance in the vehicle model using a robust observer. The estimated roll angle and roll rate are used to compute the rollover index which is based on the prediction of the lateral load transfer. In order to anticipate rollover detection, a new method is proposed to compute the time to rollover(TTR) using the load transfer ratio(LTR). The nonlinear model, deduced from the vehicle lateral and roll dynamics, is represented by a Takagi-Sugeno(T-S) fuzzy model. This representation is used to account for the nonlinearities of lateral cornering forces. The proposed T-S observer is designed with unmeasurable premise variables to cater for non-availability of the slip angles measurement. The proposed approach is evaluated using Car Sim simulator under different driving scenarios. Simulation results show good efficiency of the proposed T-S observer and the rollover detection method.

关键词： Vehicle rollover vehicle dynamics Takagi-Sugeno(T-S) fuzzy model observer uncertainties Lyapunov method linear matrix inequalities(LMI)

Hepatitis B virus mutations potentially conferring adefovir/ tenofovir resistance in treatment-naive patients

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World Journal of Gastroenterology 2009年第6期15卷 753-755页

作者： Rebecca Pastor Franois Habersetzer Samira Fafi-Kremer Michel Doffoёl Thomas F Baumert Jean-Pierre Gut Franoise Stoll-Keller Evelyne Schvoerer Laboratoire de Virologie CHRU de Strasbourg3 Rue Koeberlé67000 StrasbourgFrance Service d'Hépato-gastroentérologie Nouvel Hpital Civil1 Place de l'Hpital67091 StrasbourgFrance Inserm U 748 Strasbourg3 Rue Koeberlé67000 StrasbourgFrance Université Louis Pasteur Facultéde Médecine4 Rue Kirschleger67084 StrasbourgFrance

Anti-hepatitis B virus(HBV)therapy leads to the emer- gence of mutant viral strains during the treatment of chronic hepatitis B with nucleos(t)ides analogues. The existence of HBV variants with primary antiviral resistance may be important for treatment choice. We studied two patients with chronic HBV infection by sequencing the HBV polymerase *** had adefovir-and tenofovir-related mutations in the viral polymerase,although they had never been treated. These mutations were rtV214A/rtN238T in one patient and rtA194T in the ***,mutations in untreated patients deserve cautious *** data indicate that mutations that can theoretically confer adefovir or tenofovir resistance may emerge in treatmentnaive patients.

关键词： Hepatitis B virus Viral polymerase mutations Treatment-naive patients