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Multivariate Approach to Characterizing Soil Quality of Gabonese’s Ferralitic Soils

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 (WQIadd and WQIcom) 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 K+ and Mg2+, 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, WQIadd and NQI, whereas the total was observed with WQIcom. 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, WQIadd and NQI into the TDS and MDS approaches. The same sensitivity index value (1.53) was obtained with AQI and WQIadd. However, WQIadd was chosen as the best SQI model, according to its high linear regression value (R2 = 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

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Hexavalent Chromium Cr (VI) Removal from Water by Mango Kernel Powder

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Journal of Materials Science and Chemical Engineering 2024年第1期12卷 84-103页

作者： Amadou Sarr Gning Cheikh Gaye Antoine Blaise Kama Pape Abdoulaye Diaw Diène Diégane Thiare Modou Fall laboratoire de Chimie Physique Organique et d’analyses environnementales (LCPOAE) Université Cheikh Anta Diop Dakar Sénégal Equipe Chimie des Matériaux Inorganique et Organique (ECMIO) Université Alioune Diop Bambey Sénégal Equipe des Matériaux Electrochimie et Photochimie Analytiques (EMEPA) Université Alioune Diop Bambey Sénégal laboratoire de Photochimie et d’analyse (LPA) Université Cheikh Anta Diop Dakar Sénégal

Metal trace elements (MTE) are among the most harmful micropollutants of natural waters. Eliminating them helps improve the quality and safety of drinking water and protect human health. In this work, we used mango kernel powder (MKP) as bioadsorbent material for removal of Cr (VI) from water. Uv-visible spectroscopy was used to monitor and quantify Cr (VI) during processing using the Beer-Lambert formula. Some parameters such as pH, mango powder, mass and contact time were optimized to determine adsorption capacity and chromium removal rate. Adsorption kinetics, equilibrium, isotherms and thermodynamic parameters such as ΔG˚, ΔH˚, and ΔS˚, as well as FTIR were studied to better understand the Cr (VI) removal process by MKP. The adsorption capacity reached 94.87 mg/g, for an optimal contact time of 30 min at 298 K. The obtained results are in accordance with a pseudo-second order Freundlich adsorption isotherm model. Finally FTIR was used to monitor the evolution of absorption bands, while Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) were used to evaluate surface properties and morphology of the adsorbent.

关键词： Adsorption Chromium Mango Kernel Powder Spectroscopy Analysis Water Treatment

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再论相似于Mobius函数的可乘函数

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中国科学：数学 2024年第9期54卷 1313-1324页

作者：刘青阳吴杰中国人民大学数学学院北京100872 CNRS LAMA 8050 Laboratoire d'Analyse et de Mathematiques AppliqueesUniversite Paris-Est Creteil94010 Crteil CedexFrance

设k≥2是一个正整数,f(n)是一个可乘算术函数,其Dirichlet级数F(s)具有如下形式:F(s)={L(s,χ)H(s)ζ(ks)−1,若k为偶数,L(s,χ)H(s)L(ks,χ)−1,若k为奇数,其中,ζ是Riemannζ-函数,χ是一个模q>3的非主Dirichlet特征,L(s,χ)是相应的Dirichlet L-函数,且H(s)=Σ∞n=1 h(n)n^(−s)是在半平面ℜe s>0上绝对收敛的Dirichlet级数,对σ>0及某个常数A≥0满足Σ∞n=1|h(n)|n−σ≪σ^(−A).本文得到f(n)的部分和函数的上界估计及Ω-结果,这些结果改进并推广了Aymone等(2022)的最新结果.

关键词：可乘函数 Mobius函数 Dirichlet级数

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Evaluation of the Inhibitory Gel Aloe vera against Corrosion of Reinforcement Concrete in NaCl Medium

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Materials Sciences and Applications 2024年第5期15卷 101-112页

作者： Malang Bodian Dame Keinde Kinda Hannawi Modou Fall Aveline Darquennes Prince William Agbodjan laboratoire de Chimie Physique Organique et d’ Analyse Environnementales (LCPOAE) D&#233partement de Chimie Universit&#233 Cheikh Anta Diop de Dakar Dakar Senegal laboratoire de Gé nie Civil et G&#233nie M&#233canique (LGCGM) INSA Rennes Universit&#233 de Rennes Rennes France Civil Engineering Materials Laboratory (LMGC) Ecole Sup&#233rieure Polytechnique de Dakar (Senegal) Universit&#233 Cheikh Anta Diop Dakar S&#233n&#233gal

Most reinforced concrete structures in seaside locations suffer from corrosion damage to the reinforcement, limiting their durability and necessitating costly repairs. To improve their performance and durability, we have investigated in this paper Aloe vera extracts as a green corrosion inhibitor for reinforcing steel in NaCl environments. Using electrochemical methods (zero-intensity chronopotentiometry, Tafel lines and electrochemical impedance spectroscopy), this experimental work investigated the effect of these Aloe vera (AV) extracts on corrosion inhibition of concrete reinforcing bar (HA, diameter 12mm) immersed in a 0.5M NaCl solution. The results show that Aloe vera extracts have an average corrosion-inhibiting efficacy of around 86% at an optimum concentration of 20%.

关键词： Reinforced Concrete Green Inhibitor Corrosion Reinforcement Electrochemical Methods

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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

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Tree structure and diversity shape the biomass of primary temperate mountain forests

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Forest Ecosystems 2024年第4期11卷 568-579页

作者： Dheeraj Ralhan Ruffy Rodrigo Heather Keith Annemiek Irene Stegehuis Jakob Pavlin Yumei Jiang Milos Rydval Juliana Nogueira Alexandre Fruleux Marek Svitok Martin Mikolas Daniel Kozak Martin Dusatko Pavel Janda Oleh Chaskovsky Catalin-Constantin Roibu Miroslav Svoboda Czech University of Life Sciences Prague Faculty of Forestry and Wood SciencesKamycka 129Suchdol16521 Praha 6Czech Republic department of Forest Science Biliran Province State UniversityBiliran6549Philippines Griffith Climate Action Beacon Griffith UniversityParklands DriveSouthportGold CoastQueensland4222Australia laboratoire de Geologie IPSLCNRSUMR 8538Ecole Normale SuperieurePSL UniversityParisFrance Univ.Lille Institut Mines-TelecomUniv.ArtoisJuniaULR 4515LGCgELaboratoire de Genie Civil et Geo-EnvironnementF-59000LilleFrance department of Biology and General Ecology Faculty of Ecology and Environmental SciencesTechnical University in ZvolenMasaryka 2496001ZvolenSlovakia Institute of Forest Management Ukrainian National Forestry UniversityLvivUkraine Forest Biometrics Laboratory–Faculty of Forestry Stefan Cel Mare University of SuceavaUniversitații Street Number.13Suceava720229Romania

Primary forests are spatially diverse terrestrial ecosystems with unique characteristics,being naturally regenerative and heterogeneous,which supports the stability of their carbon storage through the accumulation of live and dead ***,little is known about the interactions between biomass stocks,tree genus diversity and structure across a temperate montane primary ***,we investigated the relationship between tree structure(variability in basal area and tree size),genus-level diversity(abundance,tree diversity)and biomass stocks in temperate primary mountain forests across Central and Eastern *** used inventory data from726 permanent sample plots from mixed beech and spruce across the Carpathian *** used nonlinear regression to analyse the spatial variability in forest biomass,structure,and genus-level diversity and how they interact with plot-level tree age,disturbances,temperature and *** found that the combined effects of genus and structural indices were important for addressing the variability in biomass across different spatial *** processes in disturbance regimes and uneven tree age support forest hete rogeneity and the accumulation of live and dead biomass through the natural regeneration,growth and decay of the forest *** complexities in basal area index,supporte d by genus-level abundance,positively influence total biomass stocks,which was modulated by tree age and *** forests showed higher tree density and basal area than mixed beech forests,though mixed beech still contributes significantly to biomass across *** heterogeneity was strongly influenced by complexities in forest composition(tree genus diversity,structure).We addressed the importance of primary forests as stable carbon stores,achieved through structure and *** such ecosystems is critical for ensuring the stability of the primary forest,carbon store and biodiversity into the future.

关键词： Biodiversity indicators Biomass carbon stock Ecosystem functioning Forest composition Primary forest structure Tree size distribution

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Effect of Water Quality on Heavy Metal Redistribution and Mobility in Polluted Agricultural Soils in a Semi-Arid Region

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Pedosphere 2019年第6期29卷 730-739页

作者： Rim AZOUZI Abdelkrim CHAREF Lamia AYED Samia KHADHAR laboratoire Géoressources Centre des Recherches et Technologies des EauxSoliman 8020(Tunisia) laboratoire d’analyse Traitement et Valorisation des Polluants de l’Environnement et des ProduitsFacultéde PharmacieRue AvicenneMonastir 5000(Tunisia)

Mornag Plain is a coastal area of the Mediterranean basin, which has undergone an agricultural industrial boom. The aim of this study was to investigate the different water qualities used for irrigation on heavy metal mobility in these polluted agricultural soils. The geo-accumulation indices for heavy metals (Ni, Cr, Pb, Cd, Cu, and Zn) revealed that industrial activities and used treated wastewater (TWW) contributed to soil pollution, and water irrigation always decreased this contamination. After long-term use of different water types, high perturbation of heavy metal redistribution has occurred. Groundwater use altered all heavy metal redistributions in the irrigated soil among various soil-solid and soil-solution fractions, as compared to the unirrigated soil. Slight acid water use transferred some metals from different solid phase components into water-soluble and exchangeable fractions. However, TWW use transformed some Ni, Cr, Cd, Cu, and Zn from water-soluble and exchangeable fractions to less labile fractions, particularly into organically bound fractions. Reuse of conventional water within the same soil decreased the whole soil redistribution index values, indicating tendency to return to the pattern of distribution of groundwater-irrigated soil.

关键词： Exchangeable fraction Geo-accumulation index Labile fraction Mobility factor Organically bound fraction Redistribution index Treated wastewater Water-soluble fraction

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Mg(OH)_2 Nanorods Synthesized by A Facile Hydrothermal Method in the Presence of CTAB

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Nano-Micro Letters 2011年第3期3卷 153-159页

作者： Hassouna Dhaouadi Hedia Chaabane Fathi Touati "laboratoire des Matriaux Utiles" Institut National de Recherche et d’analyse Physico-chimique Ple technologique de Sidi-Thabet "laboratoire de Microbiologie" Institut National de Recherche et d’analyse Physico-chimique Ple technologique de Sidi-Thabet

Magnesium hydroxide(Mg(OH)_2) nanorods were synthesized by a simple and facile hydrothermal method in the presence of cetyltetramethylammonium bromide(CTAB) as a surfactant. Nanorods of magnesium oxide Mg O were also induced by thermal decomposition of Mg(OH)_2 nanorods at 700. By using disk diffusion technique, the Mg(OH)_2 nanorods were found to exhibit higher antibacterial efficiency against several tested bacterial strains.

关键词： Nanorods Morphology Hydrothermal synthesis

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Physico-chemical and mechanical properties of Ti_3SiC_2-based materials elaborated from SiC/Ti by reactive spark plasma sintering

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Journal of Advanced Ceramics 2019年第1期8卷 47-61页

作者： Faten TURKI Houyem ABdeRRAZAK Frédéric SCHOENSTEIN Florent TêTARD Mohieddine ABdeLLAOUI Noureddine JOUINI laboratoire des Matériaux Utiles Institut National de Recherche et d’Analyse Physico-chimique laboratoire de Sciences des Procédés et Matériaux Université Paris 13 Sorbonne Paris Cité CNRS

In this paper, the synthesis of Ti_3 SiC_2 from SiC/Ti powder using reactive spark plasma sintering(R-SPS) in the temperature range of 1300-1400 ℃ is reported. The results show that the purity of Ti_3 SiC_2 is improved up to 75 wt% when the holding time is increased from 10 to 20 min at1400 ℃. The thermodynamic and experimental results indicate that Ti_3 SiC_2 formation takes place via the reaction of a pre-formed TiC phase with the silicides, formed from the eutectic *** analysis of mechanical behaviour indicates that samples with higher percentage of secondary phases exhibit higher microhardness and better resistance compared to the near single phase Ti_3 SiC_2.

关键词： Ti3SiC2 reactive spark plasma sintering(R-SPS) density mechanical properties

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On a non-autonomous reaction-convection diffusion model to study the bacteria distribution in a river

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International Journal of Biomathematics 2017年第6期10卷 25-49页

作者： Imene Meriem Mostefaoui Ali Moussaoui laboratoire de Mathematiques Image et Applications Universite de La Rochelle Pdle Sciences et Technologies Avenue Michel Crepeau 17000 La Rochelle France laboratoire D'analyse Non Lineaire et Mathematiques Appliquees Universite de Tlemcen Tlemcen Algeria laboratoire D'analyse Non Lineaire et Mathematiques Appliquees departement de Mathematique Faculte des Sciences Universite de Tlemcen Tlemcen Algeria

In this paper, we propose a non-autonomous convection-reaction diffusion system （CDI） with a nonlinear reaction source function. This model refers to the quantification and the distribution of antibiotic resistant bacteria （ARB） in a river. The main contributions of this paper are：（i） the determination of the limit set of the system by applying the semigroups theory, it is shown that it is reduced to the solutions of the associated elliptic system （CDI）e, （ii） sufficient conditions for the existence of a positive solution of （CDI）e based on the Leray-Schauder＇s degree theory. Numerical simulations which support our theoretical analysis are also given.

关键词： Reaction-diffusion systems steady states problems degree theory semi-groups.

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