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Lateral ring compression test applied to a small caliber steel jacket:Identification of a constitutive model

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defence Technology（防务技术） 2024年第6期36卷 133-148页

作者： Yann Coget Yael demarty Christophe Czarnota Anthony Bracq Jean-sebastien Brest Alexis Rusinek French-german Research Institute of saint-Louis 5 Rue Du General Cassagnou68300 Saint-LouisFrance laboratoire d'etude des Microstructures et de Mecanique des Materiaux(LEM3) CNRSUniversite de LorraineArts&Metiers ParisTechF-57000 MetzFrance

The evolution of threats and scenarios requires continuous performance improvements of ballistic protections for armed *** a modeling point of view,it is necessary to use sufficiently precise material behavior models to accurately describe the phenomena observed during the impact of a projectile on a protective *** this context,the goal of this paper is to characterize the behavior of a small caliber steel jacket by combining experimental and numerical *** experimental method is based on the lateral compression of ring specimens directly machined from the thin and small *** speeds and temperatures are considered in a quasi-static regime in order to reveal the strain rate and temperature dependencies of the tested *** Finite Element Updating Method(FEMU)is *** results are coupled with an inverse optimization method and a finite element numerical model in order to determine the parameters of a constitutive model representative of the jacket *** of the present model are verified against experimental results and a parametric study as well as a discussion on the identified material parameters are *** results indicate that the strain hardening parameter can be neglected and the behavior of the thin steel jacket can be described by a modeling without strain hardening sensitivity.

关键词： Full metal jacket ammunition Lateral ring compression Inverse identification Numerical simulation

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Electrochemical study of the Corrosion Inhibitory Capacity of Calcined Attapulgite in Reinforced Concrete Medium

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Advances in Materials Physics and Chemistry 2024年第5期14卷 76-94页

作者： Malang Bodian Kinda Hannawi dame Keinde Modou Fall Aveline darquennes Prince William Agbodjan Faculté des Sciences et Techniques D&#233partement de Chimie Universit&#233 Cheikh Anta Diop de Dakar (S&#233n&#233gal) Laboratoire de Chimie Physique Organique et d&#8217Analyse Environnementales (LCPOAE) Dakar Senegal dé partement de G&#233nie Civil Universit&#233 de Rennes INSA Rennes Laboratoire de G&#233nie Civil et G&#233nie M&#233canique (LGCGM) Rennes France dé partement de G&#233nie Civil Universit&#233 Cheikh Anta Diop Ecole Sup&#233rieure Polytechnique de Dakar (S&#233n&#233gal) Laboratoire de Mat&#233riaux de G&#233nie Civil (LMGC) Dakar Senegal

The durability of reinforced concrete structures is greatly influenced by the corrosion of the reinforcement. In addition to air pollution related to the repair of corroded structures, chloride ions are the main factors of corrosion of reinforced concrete structures. This study aims to valorize a clay inhibitor against reinforcement corrosion in reinforced concrete. This clay (Attapulgite) was incorporated into reinforced concretes at different percentages of substitution of calcined attapulgite (0%, 5% and 10%) to cement in the formulation. The corrosion inhibitory power of attapulgite is evaluated in reinforced concretes subjected to the action of chloride ions at different intervals in the NaCl solution (1 day, 21 days and 45 days) by electrochemical methods (zero current chronopotentiometry, polarization curves and electrochemical impedance spectroscopy). This study showed that in the presence of chloride ions, the composition based on 10% attapulgite has an appreciable inhibitory effect with an average inhibitory efficiency of 82%.

关键词： Attapulgite Electrochemical Methods Inhibitor Reinforced Concrete

A global analysis of the introduction pathways and characteristics associated with non-native fish species introduction, establishment, and impacts

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Ecological processes 2024年第2期13卷 16-31页

作者： Camille Bernery Céline Bellard Franck Courchamp sébastien Brosse Boris Leroy CNRs Agro Paris Tech Ecologie Systématique Evolution Université Paris-Saclay Unité Biologie des Organismes et Ecosystèmes Aquatiques (BOREA UMR 8067) Muséum National d’Histoire Naturelle Sorbonne Universités Université de Caen Normandie Université des Antilles CNRS IRD laboratoire évolution & diversité Biologique (EdB UMR5174) Université Paul Sabatier-Toulouse 3 CNRS IRD UPS

Background The invasion success of introduced freshwater fishes is influenced by many factors, including ecological, species, and socioeconomic characteristics. Most studies that document the importance of these characteristics are conducted at local scales and/or focus on a single step of the invasion process. In this study, we aim to determine the species characteristics, ecological characteristics, and socioeconomic characteristics of non-native freshwater fish invasions. Our assessment was done at the global scale and considers all three steps of the invasion(i.e., introduction, establishment, and impact). For this purpose, we applied generalized linear models to 20 variables collected for 307 non-native species and modeled them as a function of ecological characteristics(i.e., environmental features), species traits(i.e., functional and morphological), and socioeconomic characteristics(i.e., human use and introduction pathways). We considered the number of countries in which each species was introduced, established, or had ecological impacts as a proxy of invasion step success. We also explored the specifics of species introduced through the aquaculture and the ornamental fish trade *** We found that non-native freshwater fishes with broad diets, high parental care, and multiple introduction pathways are the most widely introduced and established worldwide. The number of countries with impacts reported was best explained by the type of introduction pathway(i.e., aquaculture or fisheries). Moreover, among non-native species introduced through aquaculture, those belonging to Cypriniformes and having broad diets were the most widely introduced and established species. In contrast, the species introduced through the ornamental fish trade pathway belonged to various taxonomic orders but were mainly native to tropical *** Considering several types of factors is important when analyzing the invasion success of freshwater fish and disentang

关键词： Aquaculture Ecology Exotic Freshwater fish Introduction pathway Invasion step Morphology Ornamental fish trade socioeconomic Trait

Purity-dependent Lorenz number,electron hydrodynamics and electron-phonon coupling in WTe_(2)

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science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 153-158页

作者： Wei Xie Feng Yang Liangcai Xu Xiaokang Li Zengwei Zhu Kamran Behnia Wuhan National High Magnetic Field Center and school of Physics Huazhong University of Science and TechnologyWuhan 430074China laboratoire de Physique et d’etude des Matériaux(EsPCI-CNRs-sorbonne Université)PsL University Paris 75005France

We present a study of electrical and thermal transport in Weyl semimetal WTe_(2)down to 0.3 *** Wiedemann-Franz law holds below 2 K and a downward deviation starts *** deviation is more pronounced in cleaner samples,as expected in the hydrodynamic picture of electronic transport,where a fraction of electron-electron collisions conserve *** are the dominant heat carriers and their mean-free-path does not display a Knudsen *** is presumably a consequence of weak anharmonicity,as indicated by the temperature dependence of the specific *** momentum exchange between phonons and electrons leads to quantum oscillations of the phononic thermal ***-grüneisen picture of electron-phonon scattering breaks down at low temperature when Umklapp ph-ph collisions cease to be a sink for electronic flow of *** with semi-metallic sb shows that normal ph-ph collisions are amplified by *** both semimetals,at cryogenic temperature,e-ph collisions degrade the phononic flow of energy but not the electronic flow of momentum.

关键词： thermal conductivity Wiedemann-Franz law electron hydrodynamics electron-phonon coupling

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Finite-temperature ductility-brittleness and electronic structures of Al_(n)sc(n=1,2 and 3)

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Rare Metals 2024年第8期43卷 3974-3989页

作者： Xue-Qian Wang Ying Zhao Hao-Xuan Liu shu-Chen sun Hong-Bo Yang Jia-Min Zhong gan-Feng Tu song Li Yu-dong Zhang Claude Esling Hai-Le Yan Liang Zuo Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Material Science and EngineeringNortheastern UniversityShenyang 110819China school of Metallurgy Northeastern UniversityShenyang 110819China Rare Earth Functional Materials(Xiong'an)Innovation Center Co. Ltd.Xiong'an 071700China laboratoire d'étude des Microstructures et de Mécanique des Matériaux(LEM3) Unikersitéde Lorraine57045MetzFrance

Finite-temperature ductility-brittleness and electronic structures of Al_(3)sc,Al_(2)sc and Alsc are studied comparatively by first-principles calculations and ab initio molecular *** show that Al_(3)sc and Al_(2)sc are brittle at both ground state and finite temperatures,while Alsc possesses a significantly superior *** ground state,Alsc is ductile from Pugh's and Poisson's criteria,while it is brittle in Pettifor's *** ductility of all Al_(3)sc,Al_(2)sc and AIsc improves greatly with the elevated ***,the Cauchy pressure of Alsc undergoes a transition from negative to *** T>600 K,Alsc is unequivocally classified as ductile from all criteria *** all compounds,the Al-Al bond originated from s-p and p-p orbital hybridizations,and the Al-sc bond dominated by p-d covalent hybridization,are the first and second strongest chemical bonds,*** explain the difference in mechanical properties,the mean bond strength(MBs)is introduced in this *** weaker Al-Al bond in Alsc,leading to a smaller MBs,could be the origin of the softer elastic stiffness and superior intrinsic *** longer length of the Al-Al bond in Alsc is responsible for its weaker bond ***,the enhanced metallicity of the Al-Al bond in Alsc would also contribute to its exceptional *** longer length of the Al-Al bond in AIsc is responsible for its weaker bond ***,the enhanced metallicity of the Al-Al bond in Alsc would also contribute to its exceptional ductility.

关键词： Al-sc Target materials Intrinsic ductility Finite-temperature elastic constant First-principles calculation

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Modelling the viscoplastic behaviour of Callovo-Oxfordian claystone with consideration of damage effect

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Journal of Rock Mechanics and geotechnical Engineering 2024年第1期16卷 303-316页

作者： Hao Wang Yu-Jun Cui Minh Ngoc Vu Jean Talandier Ecole des Ponts ParisTech Laboratoire Navier/CERMES6 et 8 avenue Blaise PascalMarne La Vallée cedex 277455France Andra R&D DepartmentChâtenay-Malabry92290France

In order to evaluate the performance of deep geological disposal of radioactive waste,an underground research laboratory(URL)was constructed by Andra in the Callovo-Oxfordian(COx)claystone formation at the Meuse/Haute-Marne(MHM).The construction of URL induced the excavation damage of host formations,and the ventilation in the galleries desaturated the host formation close to the gallery ***,it is expected that the mechanical behaviour of COx claystone is *** study presents a constitutive model developed to describe the viscoplastic behaviour of unsaturated and damaged COx *** this model,the unsaturation effect is considered by adopting the Bishop effective stress and the van genuchten(Vg)water retention *** terms of the viscoplastic behaviour,the nonstationary flow surface(NsFs)theory for unsaturated soils is used with consideration of the coupled effects of strain rate and suction on the yield stress.A progressive hardening law is ***,a non-associated flow rule is used,which is similar to that in Barcelona basic model(BBM).In addition,to describe the damage effect induced by suction change and viscoplastic loading,a damage function is defined based on the crack volume *** damage function contains two variables:unsaturated effective stress and viscoplastic volumetric strain,with the related parameters determined based on the mercury intrusion porosimetry(MIP)*** the model validation,different tests on COx claystone under different loading paths are *** between experimental and simulated results indicated that the present model is able to well describe the viscoplastic behaviour of damaged COx claystone,including swelling/shrinkage,triaxial extension and compression,and triaxial creep.

关键词： Callovo-Oxfordian(COx)claystone Excavation damage Time-dependent behaviour suction Viscoplastic model

detection of Burned Areas through spectral Indices Analysis of sentinel-2A satellite Images in the Abokouamékro Wildlife Reserve (Central, Côte d’Ivoire)

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Open Journal of Applied sciences 2024年第1期14卷 205-222页

作者： Bob Kouakou Kouadio sié Ouattara Alain Clément Jean-Marc gala Bi Zaouri Jean-Luc Kouadio Kouassi Jean-Luc Edouard Kouakou N’guessan laboratoire des sciences et Technologies de la Communication et de l’Information (LsTCI) Institut National Polytechnique Houphou&#235t Boigny (INP-HB) Yamoussoukro C&#244te d’Ivoire laboratoire des sciences Agronomiques et génie Rural Institut National Polytechnique Houphou&#235t Boigny (INPHB) Yamoussoukro C&#244te d’Ivoire Ecole de géomatique et du Territoire (EgT) Abidjan C&#244te d’Ivoire LARIs SFR MATHSTIC Université d’Angers Angers France Centre Universitaire de Recherche et d’application en Télédétection (CURAT) UFR des Sciences de la Terre et des Ressources Minières Abidjan C&#244te d’Ivoire laboratoire de Botanique UFR Biosciences Université Félix Houphou&#235t Boigny Abidjan C&#244te d’Ivoire

In Côte d’Ivoire, the recurring and unregulated use of bushfires, which cause ecological damage, presents a pressing concern for the custodians of protected areas. This study aims to enhance our comprehension of the dynamics of burnt areas within the Abokouamékro Wildlife Reserve (AWR) by employing the analysis of spectral indices derived from satellite imagery. The research methodology began with the calculation of mean indices and their corresponding spectral sub-indices, including NdVI, sAVI, NdWI, NdMI, BAI, NBR, TCW, TCg, and TCB, utilizing data from the sentinel-2A satellite image dated January 17, 2022. subsequently, a fuzzy classification model was applied to these various indices and sub-indices, guided by the degree of membership α, with the goal of effectively distinguishing between burned and unburned areas. Following the classification, the accuracies of the classified indices and sub-indices were validated using the coordinates of 100 data points collected within the AWR through gPs technology. The results revealed that the overall accuracy of all indices and sub-indices declines as the degree of membership α decreases from 1 to 0. Among the mean spectral indices, NdVI-mean, sAVI-mean, NdMI-mean exhibited the highest overall accuracies, achieving 97%, 95%, and 90%, respectively. These results closely mirrored those obtained by sub-indices using band 8 (NdVI-B8, sAVI-B8, and NdMI-B8), which yield respective overall accuracies of 93%, 92%, and 89%. At a degree of membership α = 1, the estimated burned areas for the most effective indices encompassed 2144.38 hectares for NdVI-mean, 1932.14 hectares for mean sAVI-mean, and 4947.13 hectares for mean NdMI-mean. A prospective approach involving the amalgamation of these three indices could have the potential to yield improved outcomes. This study could be a substantial contribution to the discrimination of bushfires in Côte d’Ivoire.

关键词： spectral Indices Wildfire Burned Areas Abokouamékro Wildlife Reserve Côte d’Ivoire

Multivariate Approach to Characterizing soil Quality of gabonese’s Ferralitic soils

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Open Journal of soil science 2024年第4期14卷 237-268页

作者： Neil-Yohan Musadji Rolf gaël Mabicka Obame Michel Mbina Mounguengui Jean Aubin Ondo Lydie-stella Koutika Eric Ravire Claude geffroy laboratoire de Chimie Des Milieux et Des Mat&#233riaux Inorganiques Laboratoire D&#8217Analyse Des Sols et Environnement D&#233partement Des Sciences Fondamentales De L&#8217Ing&#233nieur Institut National D&#8217Agronomie et De Biotechnologies Universit&#233 Des Sciences et Techniques De Masuku Franceville Gabon Institut de Chimie des Milieux et Maté riaux De Poitiers (IC2MP) Universit&#233 De Poitiers Poitiers France laboratoire de Chimie Des Milieux et Des Mat&#233riaux Inorganiques Laboratoire D&#8217Analyse Des Sols et Environnement D&#233partement De Phytotechnologie Institut National D&#8217Agronomie et De Biotechnologies Universit&#233 Des Sciences et Techniques De Masuku Franceville Gabon dé partement De G&#233ologie Facult&#233 Des Sciences Universit&#233 Des Sciences et Techniques De Masuku Franceville Gabon laboratoire Pluridisciplinaire des sciences Ecole Normale Sup&#233rieure Libreville Gabon Centre de Recherche sur La Productivité et La Durabilit&#233 Des Plantations Industrielles Pointe Noire Republic of Congo sucaf gabon somdiaa Franceville Gabon

Assessing soil quality is essential for crop management and soil temporal changes. The present study aims to evaluate soil quality in the Ferralitic soils context countrywide. This assessment was done using multivariate soil quality indice (sQI) models, such as additive quality index (AQI), weighted quality indexes (WQIsub>addsub> and WQIsub>comsub>) and Nemoro quality index (NQI), applied to two approaches of indicator selection: total data set (Tds) and minimum data set (Mds). Physical and chemical soil indicators were extracted from the ORsTOM’s reports resulting from a sampling campaign in different provinces of gabon. The Tds approach shows soil quality status according to eleven soil indicators extracted from the analysis of 1,059 samples from arable soil layer (0 - 30 cm depth). The results indicated that 87% of all provinces presented a very low soil quality (Q5) whatever the model. Among soil indicators, exchangeable Ksup>+sup> and Mgsup>2+sup>, bulk density and C/N ratio were retained in Mds, using principal component analysis (PCA). In the Mds approach, 50 to 63% of provinces had low soil quality grades with AQI, WQIsub>addsub> and NQI, whereas the total was observed with WQIsub>comsub>. Only 25% of provinces had medium soil quality grades with AQI and NQI models, while 12.5% (NQI) and 25% (AQI) presented high quality grades. Robust statistical analyses confirmed the accuracy and validation (0.80 r P ≤ 0.016) of AQI, WQIsub>addsub> and NQI into the Tds and Mds approaches. The same sensitivity index value (1.53) was obtained with AQI and WQIsub>addsub>. However, WQIsub>addsub> was chosen as the best sQI model, according to its high linear regression value (Rsup>2sup> = 0.82) between Tds and Mds. This study has important implications in decision-making on monitoring, evaluation and sustainable management of gabonese soils in a pedoclimatic context unfavorable to plant growth.

关键词： gabon Ferralitic soil soil Indicators standard score Function soil Quality Indices sustainable soil soil Management

Microbiological Quality of Cyperus esculentus L. Products sold in Ouagadougou and Bobo dioulasso (Burkina Faso)

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Open Journal of Applied sciences 2024年第3期14卷 635-642页

作者： Zénabou semdé Passinguemsin Alice sonia Tiendrebeogo Bahanla Edwige Oboulbiga Charles Parkouda Hagrétou sawadogo Lingani laboratoire des sciences et Technologies des Aliments et Nutrition Département technologie alimentaire IRSAT CNRST Ouagadougou Burkina Faso

This study aimed to assess the microbiological quality of tiger nut (Cyperus esculentus L.) products sold in Ouagadougou and Bobo dioulasso. The microbial load of tubers and tiger nut milk was determined using IsO 4833-1 (2003) standard (total mesophilic aerobic flora), NF IsO 7954 (1998) standard (yeasts and molds), and IsO 4832 (2006) standard (total coliforms, thermotolerant coliforms). The results showed that tiger nut tubers had an average microbial load between 4.86 ± 7.03 × 10sup>6sup> UFC/g and 1.82 ± 2.30 × 10sup>7sup> UFC/g for total mesophilic aerobic flora, from 4.34 ± 10.6 × 10sup>5sup> UFC/g to 3.52 ± 4.54 × 10sup>6sup> UFC/g for yeasts and molds, from 2.23 ± 2.25 × 10sup>5sup> UFC/g to 1.41 ± 2.16 × 10sup>5sup> UFC/g for total coliforms and from 1.83 ± 2.03 × 10sup>5sup> UFC/g to 7.0 ± 10.8 × 10sup>4sup> CFU/g for thermotolerant coliforms. For tiger nut milk samples, the average microbial load varied from 3.48 ± 2.98 × 10sup>6sup> CFU/g to 2.80 ± 5.69 × 107 CFU/g for total mesophilic aerobic flora, from 5.00 ± 7.21 × 10sup>4sup> CFU/g to 1.88 ± 3.31 × 10sup>5sup> CFU/g for yeasts and molds, from 4.58 ± 10.4 × 10sup>4sup> CFU/g to 6.31 ± 9.17 × 10sup>5sup> CFU/g for total coliforms and 7.00 ± 7.00 × 10sup>3sup> CFU/g to 2.87 ± 5.86 × 10sup>5sup> CFU/g for thermotolerant coliforms. This study revealed that the tubers and tiger nut milk sold in Ouagadougou and Bobo dioulasso had a high microbial load which could lead to the degradation of these products and food poisoning for consumers.

关键词： Cyperus esculentus L. Tiger Nut Tubers Tiger Nut Milk Microbiological Quality