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Numerical Modelling of the Transient Hygroscopic Behavior of Flax-Epoxy Composite

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Journal of Renewable Materials 2019年第9期7卷 839-853页

作者： Wajdi Zouari Mustapha Assarar Abderrazak Chilali Rezak Ayad Hocine Kebir Universitéde Reims Champagne-Ardenne ITheMM EA 754851097ReimsFrance Ecole nationale Préparatoire aux Etudes d’Ingéniorat 16012RouïbaAlgeria sorbonne Universités Universitéde Technologie de CompiègneLaboratoire Roberval(UMR 7337)60205CompiègneFrance

This contribution deals with the development of a three-node triangular plane finite element to analyze the transient hygroscopic behavior of 2/2 twill flax fabric-reinforced epoxy *** plates of this material were fabricated using the vacuum infusion process and composite specimens were then cut and aged in tap water at room temperature until *** simplify,a plane modelling of water diffusion in the aged specimens is adopted and Fick’s model is used to describe the water diffusion *** highlight the heterogeneity of the flax-epoxy samples,the twill flax fabrics waviness is modelled with a sinusoidal *** particular,we show that the proposed finite element formulation allows estimating the flax fiber radial diffusion coefficient by an inverse approach.

关键词： Flax-epoxy composite water ageing fick’s model finite element analysis

Multichannel imaging for monitoring chemical composition and germination capacity of cowpea(Vigna unguiculata) seeds during development and maturation

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The Crop Journal 2022年第5期10卷 1399-1411页

作者： Gamal ElMasry Nasser Mandour Yahya Ejeez Didier Demilly salim Al-Rejaie Jerome Verdier Etienne Belin David Rousseau Agricultural Engineering Department Faculty of AgricultureSuez Canal UniversityIsmailiaEgypt Groupe d’Etude et de Controle des Variétés et des semences(GEVEs) Station Nationale d’Essais de Semences(SNES)Beaucouze49071AngersFrance Department of Pharmacology&Toxicology College of PharmacyKing Saud UniversitySaudi Arabia Laboratoire Angevin de Recherche en Ingenierie des systemes(LARIs) Universited’AngersAngersFrance Institut National de la Recherche Agronomique(inra) UMR1345 Institut de Recherche en Horticulture et SemencesBeaucouzéF-49071AngersFrance

This study aimed to set a computer-integrated multichannel spectral imaging system as a high-throughput phenotyping tool for the analysis of individual cowpea seeds harvested at different developmental stages. The changes in germination capacity and variations in moisture, protein and different sugars during twelve stages of seed development from 10 to 32 days after anthesis were nondestructively monitored. Multispectral data at 20 discrete wavelengths in the ultraviolet, visible and near infrared regions were extracted from individual seeds and then modelled using partial least squares regression and linear discriminant analysis(LDA) models. The developed multivariate models were accurate enough for monitoring all possible changes occurred in moisture, protein and sugar contents with coefficients of determination in prediction R^(2) of 0.93, 0.80 and 0.78 and root mean square errors in prediction(RMsEP) of 6.045%, 2.236% and 0.890%, respectively. The accuracy of PLs models in predicting individual sugars such as verbascose and stachyose was reasonable with R~2 of 0.87 and 0.87 and RMsEP of 0.071%and 0.485%, respectively;but for the prediction of sucrose and raffinose the accuracy was relatively limited with R^(2) of 0.24 and 0.66 and RMsEP of 0.567% and 0.045%, respectively. The developed LDA model was robust in classifying the seeds based on their germination capacity with overall correct classification of96.33% and 95.67% in the training and validation datasets, respectively. With these levels of accuracy,the proposed multichannel spectral imaging system designed for single seeds could be an effective choice as a rapid screening and non-destructive technique for identifying the ideal harvesting time of cowpea seeds based on their chemical composition and germination capacity. Moreover, the development of chemical images of the major constituents along with classification images confirmed the usefulness of the proposed technique as a non-destructive tool for estim

关键词： Multispectral imaging Multichannel imaging Chemical imaging spectral analysis seeds Cowpea

Early exercise premium method for pricing American options under the J-model

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Financial Innovation 2016年第1期2卷 266-291页

作者： Yacin Jerbi Department of Computer sciences and Applied Mathematics Ecole Nationale des Ingénieurs de SfaxBPW 3038 SfaxTunisia

Background:This study develops a new model called J-am for pricing American options and for determining the related early exercise boundary(EEB).This model is based on a closed-form solution J-formula for pricing European options,defined in the study by Jerbi(Quantitative Finance,15:2041-2052,2015).The J-am pricing formula is a solution of the Black&scholes(Bs)PDE with an additional function called f as a second member and with limit conditions adapted to the American option *** aforesaid function f represents the cash flows resulting from an early exercise of the ***:This study develops the theoretical formulas of the early exercise premium value related to three American option pricing models called J-am,Bs-am,and Heston-am *** three models are based on the J-formula by Jerbi(Quantitative Finance,15:2041-2052,2015),Bs model,and Heston(Rev Financ stud,6:327-343,1993)model,*** study performs a general algorithm leading to the EEB and to the American option price for the three ***:After implementing the algorithms,we compare the three aforesaid models in terms of pricing and the EEB *** particular,we examine the equivalence between J-am and Heston-am as an extension of the equivalence studied by Jerbi(Quantitative Finance,15:2041-2052,2015).This equivalence is interesting since it can reduce a bi-dimensional model to an equivalent uni-dimensional ***:We deduce that our model J-am exactly fits the Heston-am one for certain parameters values to be optimized and that all the theoretical results conform with the empirical *** required CPU time to compute the solution is significantly less in the case of the J-am model compared with to the Heston-am model.

关键词： American option pricing stochastic volatility model Early exercise boundary Early exercise premium J-law J-process J-formula Heston model

Reactions of Maruca Resistant Transgenic Cowpea to Cowpea Aphid-Borne Mosaic Virus

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Agricultural sciences 2024年第7期15卷 742-753页

作者： Mounyratou Rabo Moustapha Ouédraogo Orokia Coulibaly Assita Traoré-Barro salimata Traoré Teyioue Benoit Joseph Batieno Chantal Kaboré-Zoungrana Aboubacar Toguyeni Oumar Traoré Laboratoire National de Bioscurit Agence Nationale de Bioscurit (ANB) Ouagadougou Burkina Faso Institut de lEnvironnement et Recherches Agricoles Dpartement Productions Vgtales Ouagadougou Burkina Faso Laboratoire dEtudes et de Recherches sur les Ressources Naturelles et les sciences de lEnvironnement (LERNsE) Universit Nazi BONI Bobo-Dioulasso Burkina Faso Laboratoire De Gntique et Amlioration Des Plantes (LAGAMEP) Institut de lEnvironnement et Recherches Agricoles Ouagadougou Burkina Faso Laboratoire De Protection et Dfense Des Cultures (LAPRODEC) Institut de lEnvironnement et Recherches Agricoles Ouagadougou Burkina Faso

Cowpea (Vigna unguiculata L. [Walp.]) in one of the main grain legumes contributing to food security and poverty alleviation in sub-saharan Africa. To control the highly damaging legume pod borer Maruca vitrata F., transgenic cowpea lines expressing the insecticidal Cry1Ab Bt protein were developed. In this study, we evaluated the impact of Cry1Ab transgene expression on the susceptibility of four cowpea lines (named IT97K-T, IT98K-T, Gourgou-T and Nafi-T) and their respective non-transgenic near isogenic lines (IT97K, IT98K, Gourgou and Nafi) to Cowpea aphid-borne mosaic virus (CABMV) in greenhouse conditions. In a preliminary quality control test by enzyme-linked immunosorbent assay, the presence of Cry1Ab protein in transgenic seed lots ranged from 59% to 72%, with no significant differences among the lines (χ2 = 3.26;p = 0.35). Upon virus inoculation, all cowpea lines exhibited mosaic symptoms with similar severity between 7- and 11-day post-inoculation. No significant differences were observed in symptom severity. significant differences were found between cowpea lines for time of symptom onset, virus accumulation in plants and days to 50% flowering. However, while comparing pairs of transgenic lines and corresponding non-transgenic lines, virus accumulation showed not significant differences whatever the pair. Time of symptom onset and days to 50% flowering did not also differ significantly between pairs of cowpea lines except Nafi/Nafi-T in which transgenic Nafi-T showed earlier symptoms (7.4 ± 0.7 vs. 8.9 ± 0.8 days post-inoculation) and shorter flowering time (37.3 ± 0.6 vs. 42 ± 1.7 days after sowing). Overall, these findings improve our understanding of the effects of Cry1Ab gene mediated genetic modification on cowpea infection by Cowpea aphid-borne mosaic virus, with potential implications for environmental safety assessment.

关键词： Cowpea Cry1Ab Cowpea Aphid-Borne Mosaic Virus Environmental safety

Effect of low temperature in the development cycle of Lucilia sericata (Meigen) (Diptera, Calliphoridae): implications for the minimum postmortem interval estimation

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Forensic sciences Research 2018年第1期3卷 52-59页

作者： Laetitia Cervantès Laurent Dourel Emmanuel Gaudry Thierry Pasquerault Benoit Vincent Forensic Fauna Flora Department Institut de Recherche Criminelle De La Gendarmerie nationaleCergy Pontoise CedexFrance

Knowledge of necrophagous insects' developmental data is necessary for the forensic entomologist to estimate a reliable minimum postmortem interval (PMImin).Among the most represented necrophagous species,Lucilia sericata (Diptera,Calliphoridae) is particularly *** is regularly identified in samples,with a predominance in summer,and is commonly used by analysts of our entomology department (Institut de Recherche Criminelle de la Gendarmerie nationale) to estimate the PMImin with the accumulated degree days (ADD) *** method requires the mathematical lower thermal threshold to be *** value dictates the quality of the applied ADD method but cannot be considered as fixed,especially when insect development occurs at temperatures close to the biological *** such conditions,it is necessary to study the influence of such temperatures on development rate,as well as the consequences of estimating the period of first oviposition on cadavers,when using the ADD *** replicate rearings were conducted at six different temperatures: 30 ℃,24 ℃,18 ℃,15 ℃,12 ℃ and 10 ℃.Time of development and time of emergence were *** effect of low temperature on the development cycle and the reliability of the ADD method under this entire temperature spectrum were studied using different linear regression *** durations of total insect time development and experimental rearing duration were then compared.A global linear model cannot be used on the whole temperature spectrum experienced by *** without resulting in an overestimation at some *** found a combination of two linear regression models to be suitable for the estimation of the total development time,depending on the temperature experienced by *** approach allowed us to obtain a variation lower than 2% at 12 ℃ and 10 ℃ between the calculated duration and experimental duration of *** comparison,the results obtained with a global model show

关键词： Forensic science forensic entomology accumulated degree days(ADD)method minimum PMI low temperature

Adaptive genetic algorithms guided by decomposition for PCsPs： application to frequency assignment problems

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Frontiers of Computer science 2016年第6期10卷 1012-1025页

作者： Lamia sADEG-BELKACEM Zineb HABBAs Wassila AGGOUNE-MTALAA Ecole Militaire Polytechnique Algiers 16111 Algeria Ecole nationale superieure d' Informatique Algiers 16309 Algeria Universite de Lorraine Metz 57045 France Luxembourg Institute of science and Technology Luxembourg L-4362 Luxembourg

This paper proposes Adaptive Genetic Algorithms Guided by structural knowledges coming from decomposition methods, for solving PCsPs. The family of algorithms called AGAGD_x_y is designed to be doubly genetic, meaning that any decomposition method and different heuristics for the genetic operators can be considered. To validate the approach, the decomposition algorithm due to Newman was used and several crossover operators based on structural knowledge such as the cluster, separator and the cut were tested. The experimental results obtained on the most challenging Minimum Interference-FAP problems of CALMA instances are very promising and lead to interesting perspectives to be explored in the future.

关键词： optimization problems partial constraint satisfaction problems frequency assignment problems graph decomposition adaptive genetic algorithm (AGA) AGA guided by decomposition (AGAGD).

Nickel ferrite spinel as catalyst precursor in the dry reforming of methane:synthesis,characterization and catalytic properties

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Journal of Natural Gas Chemistry 2012年第5期21卷 595-604页

作者： Rafik Benrabaa Hamza Boukhlouf Axel Lfberg Annick Rubbens Rose-Nelle Vannier Elisabeth Bordes-Richard Akila Barama Laboratoire de Matériaux Catalytiques & Catalyse en Chimie Organique Faculté de ChimieUSTHBBP32 El Alia16111 Bab EzzouarAlgerAlgérie unité de Catalyse et de Chimie du solide UMR CNRS 8181Ecole Nationale Supérieure de Chimie de LilleUniversitédes Sciences et Technologies de LilleCité Scientif ique59655 Villeneuve d'AscqFrance

Dry reforming of methane by CO2 using nickel ferrite as precursor of catalysts was *** ferrite crystalline particles were prepared by coprecipitation of nitrates with NaOH or ammonia followed by calcination,or by hydrothermal synthesis without calcination *** textural and structural properties were determined by a number of analysis methods,including X-ray diffraction （XRD）,Raman spectroscopy and X-ray photoelectron spectroscopy （XPs）,among which X-ray diffraction （XRD） was at room and variable *** synthesized oxides showed the presence of micro or nanoparticles of NiFe2O4 inverse spinel,but Fe2O3 （hematite） was also present when ammonia was used for *** reducibility by hydrogen was studied by temperature-programmed reduction （TPR） and in situ XRD,which showed the influence of the preparation *** surface area （BET）,particle size （Rietveld refinement）,as well as surface Ni/Fe atomic ratio （XPs） and the behavior upon reduction varied according to the synthesis *** catalytic reactivity was investigated using isopropanol decomposition to determine the acid/base *** catalytic performance of methane reforming with CO2 was measured with and without the pre-treatment of catalysts under H2 in 650-800 C *** catalytic conversions of methane and CO2 were quite low but they increased when the catalysts were pre-reduced.A significant contribution of reverse water gas shift reaction accounted for the low values of H2 /CO *** coking was observed as shown by the reoxidation step performed after the catalytic *** possible formation of nickel-iron alloy observed during the study of reducibility by hydrogen was invoked to account for the catalytic behavior.

关键词： dry reforming of methane NiFe2O4 spinel hydrothermal synthesis coprecipitation isopropanol decomposition

self-sealing of fractures in indurated claystones measured by water and gas flow

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第1期15卷 227-238页

作者： Chun-Liang Zhang Jean Talandier Gesellschaft für Anlagen-und Reaktorsicherheit(GRs) Braunschweig38122Germany Agence nationale pour la gestion des déchets radioactifs(ANDRA) Châtenay-Malabry cedex92298France

self-sealing of fractures in the indurated Callovo-Oxfordian(COX)and Opalinus(OPA)claystones,which are considered as host rocks for disposal of radioactive waste,was investigated on artificially fractured *** samples were extracted from four lithological facies relatively rich in clay mineral,carbonate and quartz,*** self-sealing of fractures was measured by fracture closure,water permeability variation,gas penetration,and recovery of gas-induced *** of the fractured samples exhibited a dramatic reduction inwater permeability to low levels that is close to that of intact rock,depending on their mineralogical composition,fracture intensity,confining stress,and load *** self-sealing capacity of the clay-rich samples is higher than that of the carbonate-rich and sandy *** effects of sample size and fracture intensity were *** sealed fractures become gas-tight for certain in-jection ***,the measured gas breakthrough pressures are still lower than the confining *** gas-induced pathways can recover when contacting *** important findings imply that fractures in such indurated claystones can effectively recover to hinder water transport but allow gas release under relatively low pressures without compromising the rock integrity.

关键词： Claystone self-sealing of fracture Fracture closure Water permeability Gas breakthrough pressure Resealing of gas pathway

A low power consumption control scheme:application to a piezostack-based active mount

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Frontiers of Mechanical Engineering 2013年第4期8卷 383-389页

作者： T.LOUKIL O.BAREILLE M.N.ICHCHOU M.HADDAR LTDs Ecolc Centrale de Lyon36 Avenue Guy de Collongue U2MP Ecole Nationale d'lngenieurs de Sfax

Piezostack-based active mounts have shown great efficiency for vibration control in a wide frequency *** this paper,we investigate the performances of the global semi-active control strategy presented by Ichchou et al.[1]for a control system consisting of an active mount and a supported *** control strategy allows extracting vibrations energy of the supported mass,storing it in accumulators to be reused for powering in part the actuators(two piezostacks).Consequently,energy needs are reduced versus good control performances comparable to those of the active control based on the negative velocity *** performances of the controller are evaluated in both frequency(transmitted force)and time(acceleration)domains which show that vibrations of the supported mass due to base excitations are efficiently attenuated with the proposed *** energetic analysis confirms the reduced energy requirement compared to the active scheme.

关键词： hybrid mount energy control piezoelectric harvesting