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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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Unraveling magnetic properties and martensitic transformation in Mn-rich Ni-Mn-Sn alloys:first-principles calculations and experiments

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Rare Metals 2024年第4期43卷 1769-1785页

作者： Yu Zhang Jing Bai Ke-Liang Guo Jia-Xin Xu Jiang-Long Gu Nicola Morley Qui-Zhi Gao Yu-dong Zhang Claude Esling Xiang Zhao Liang Zuo Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Material Science and EngineeringNortheastern UniversityShenyang110819China Key Laboratory of dielectric and Electrolyte Functional Material Hebei Province School of Resources and MaterialsNortheastern University at QinhuangdaoQinhuangdao066004China department of Material Science and Engineering University of SheffieldSheffieldS13JDUK State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao066004China laboratoire d’Étude des Microstructures Et de Mécanique des Matériaux University of Lorraine57045MetzFrance

We have investigated the phase stability,magnetic properties,and martensitic transformation thermodynamics/kinetics of the Ni_(24-x)Mn_(18+x+y)Sn_(6-y)(x,y=0,1,2)system by combining the first-principles calculations and *** calculation results show that the optimized lattice parameters are consistent with the experimental ***,we obtain the relation equation for the austenite formation energy(E_(form-A))and Mn content(X_(Mn)):E_(form-A)=507.358X_(Mn)-274.126,as well as for the six-layer modulated(6M)martensite formation energy(E_(form-6M))and Ni content(X_(Ni)):E_(form-6M)=-728.484X_(Ni)+*** ternary phase diagram of the total magnetic moment was *** excess Mn will reduce the total magnetic moment of 6M(Mag6M)and non-modulated(NM)(MagNM)martensites,with the following equations relating the total magnetic moment and Mn content:Mag_(6M)=-15.905X_(Mn)+7.902and Mag_(NM)=-14.781X_(Mn)+7.411,while the effect on austenite is *** variation of total magnetic moment is mainly dominated by the Mn atomic magnetic *** 3d electrons of Mn_(Sn)(Mn at Sn sublattice)play an important role in magnetic properties from the perspective of the electronic density of *** on the thermodynamics of martensitic transformation,the alloys will likely undergo austenite?6M?NM transformation *** the thermodynamic and kinetic results,the martensitic transformation temperature decreases with x increasing and increases with y *** results are expected to provide reference for predicting the phase stability and magnetic properties of NiMn-Sn alloys.

关键词： Ni-Mn-Sn First-principles calculations Martensitic transformation Magnetic property Kinetics

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Contribution of Satellite Observations in the Optical and Microphysical Characterization of Aerosols in Burkina Faso, West Africa

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Atmospheric and Climate Sciences 2024年第1期14卷 154-171页

作者： Nébon Bado Serge dimitri Bazyomo Germain Wende Pouiré Ouedraogo Bruno Korgo Mamadou Simina dramé Florent P. Kieno Sié Kam laboratoire d’Energies Thermiques Renouvelables (L.E.T.RE) Université Joseph KI ZERBO Ouaga Burkina Faso laboratoire de Physique de l’Atmosphère et de l’Océan Siméon-Fongang Université Cheikh Anta DIOP Dakar-Fann Sénégal Institute of Mathematics and Physical Sciences University of Abomey-Calavi Porto-Novo Benin

In this work, we proceed to an optical and microphysical analysis of the observations reversed by the MOdIS, SeaWiFS, MISR and OMI sensors with the aim of proposing the best-adapted airborne sensor for better monitoring of aerosols in Burkina Faso. To this end, a comparison of AOd between satellite observations and in situ measurements at the Ouagadougou site reveals an underestimation of AERONET AOd except for OMI which overestimates them. Also, an inter-comparison done based on the linear regression line representation shows the correlation between the aerosol models incorporated in the airborne sensor inversion algorithms and the aerosol population probed. This can be seen through the correlation coefficients R which are 0.84, 0.64, 0.55 and 0.054 for MOdIS, SeaWiFS, MISR and OMI respectively. Furthermore, an optical analysis of aerosols in Burkina Faso by the MOdIS sensor from 2001 to 2016 indicates a large spatial and temporal variability of particles strongly dominated by desert dust. This is corroborated by the annual and seasonal cycles of the AOd at 550 nm and the Angström coefficient measured in the spectral range between 412 nm and 470 nm. A zoom on a few sites chosen according to the three climatic zones confirms the majority presence of mineral aerosols in Burkina Faso, whose maxima are observed in spring and summer.

关键词： AERONET Airborne Sensors Aerosol Optical and Microphysical Properties

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Calculation of Photo-Ionisation Cross Sections and Radiative Recombination Rate Coefficients for CO and CO^+ molecules

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Plasma Science and Technology 2014年第11期16卷 1013-1019页

作者： Raja dHOUIOUI Philippe TEULET Yann CRESSAULT Hassen GHALILA Riadh RIAHI Nejm Eddine JAIdANE Zohra BEN LAKHdAR Université de Toulouse UPSINPTLAPLACE(Laboratoire Plasma et Conversion d'Energie)118 route de NarbonneF-31062 Toulouse cedex 9France laboratoire de Spectroscopic Atomique Moléculaire et Applications(LSAMA)Faculté des Sciences de TunisUniversité de Tunis el Manar1060 TunisTunisia

A method based upon the weighted total cross section （WTCS） theory is proposed to calculate the photo-ionisation cross sections and the radiative recombination rate coefficients between the fundamental level of CO and the main electronic states of its corresponding ion. Total photo-ionisation cross sections and radiative recombination rate coefficients are determined from the calculation of elementary vibrational photo-ionisation cross sections. Transitions be- tween CO＋（X, A and B） and CO（X） are considered. Total photo-ionisation cross sections and recombination coefficients are computed in the temperature interval 500-15000 K.

关键词： CO photo-ionisation cross sections radiative recombination rate coefficients

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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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Effect of Seasonal Variations on the Behavior of Flexible Pavements in Burkina Faso: Towards Alternating and Periodic Loading of Multi-Axle Heavy Goods Vehicles for Road durability

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Journal of Materials Science and Chemical Engineering 2024年第6期12卷 24-42页

作者： Kokoro Kobori doua Allain Gnabahou Bouto Kossi Imbga laboratoire de Chimie Analytique de Physique Spatiale et Energtique Universit Norbert ZONGO Koudougou Burkina Faso laboratoire dEnergie Thermique Renouvelable Universit Joseph KI-ZERBO Ouagadougou Burkina Faso

Bituminous materials are heat-sensitive, and their mechanical properties vary with temperature. This variation in properties is not without consequences on the performance of flexible road structures under the repeated passage of multi-axles. This study determines the influence of seasonal variations on the rate of permanent deformation, the rut depth of flexible pavements and the effect of alternating loading of heavy goods vehicles following the temperature variations on the durability of roads. Thus, an ambient and pavement surface temperature measurement was carried out in 2022. The temperature profile at different layers of the modelled pavement, the evaluation of deformation rates and rutting depth were determined using several models. The results show that the permanent deformation and rutting rates are higher at the level of the bituminous concrete layer than at the level of the asphalt gravel layer because the stresses decrease from the surface to the depth of the pavement. On the other hand, the variations in these rates, permanent deformations and ruts between the hot and so-called cold periods are more pronounced in the bitumen gravel than in bituminous concrete, showing that gravel bitumen is more sensitive to temperature variations than bituminous concrete despite its higher rigidity. Of these results, we suggested a periodic and alternating loading of the different types of heavy goods vehicles. These loads consist of fully applying the WAEMU standards with a tolerance of 15% during periods of high and low temperatures. This regulation has increased 2 to 3 times in the durability of roadways depending on the type of heavy goods vehicle.

关键词： Pavement Rutting Permanent deformation Multi-Axle Seasonal

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Effect of Artemisia annua (Asteraceae) Extracts on Hemolysis in Individuals with G6Pd-deficiency

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Journal of Biosciences and Medicines 2024年第3期12卷 303-315页

作者： Jescica Bonarck Sohou Casimir Jiras Kpego Ligan Salomon Ezechiel Mahougnon Fiogbe Thierry Comlan Marc Medehouenou Fifame Esperance Elvire Kougnimon Casimir dewanou Akpovi Unité de Recherche sur les Maladies Non Transmissibles et le Cancer (UR-MNTC) Laboratoire de Recherche en Biologie Appliquée Ecole Polytechnique d’Abomey-Calavi University of Abomey-Calavi Cotonou Benin

Individuals with Glucose-6-phosphate dehydrogenase (G6Pd) deficiency are susceptible to hemolytic anemia when exposed to pro-oxidant substances. This study investigates the hemolytic impact of Artemisia annua (A. annua) extracts in G6Pd-deficient subjects through a mixed experimental approach. In the in vitro phase, red blood cells from G6Pd-deficient individuals and rats induced with dehydroepiandrosterone (dHEA) were exposed to various concentrations of A. annua infusion, with distilled water and physiological saline as positive and negative controls respectively. The in vivo study involved G6Pd-deficient Wistar rats divided into three groups receiving A. annua infusion, quinine (positive control), and distilled water (negative control) via gavage. Blood samples were collected for biochemical and hematological analyses. Notably, at a 40% concentration of A. annua infusion, there was a significant increase in the hemolysis rate of G6Pd-deficient red blood cells compared to controls (p A. annua exhibited elevated aspartate aminotransferase (129.25 ± 4.55 U/L vs. 80.09 ± 4.03 U/L;p A. annua infusion tested positive for saponins. These findings underscore the risk of hemolysis in G6Pd-deficient individuals upon ingesting A. annua.

关键词： Artemisia annua Infusion Saponins G6Pd deficiency Hemolysis

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Statistical Study of the Geoeffectivity of Halo Coronal Mass Ejections Associated with X-Class Flares during Solar Cycles 23 and 24

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Open Journal of Applied Sciences 2024年第4期14卷 950-960页

作者： Younoussa diakite Christian Zoundi M’Bi Kabore Jean Louis Zerbo laboratoire de Chimie Analytique de Physique Spatiale et Energ&#233tique (L@CAPSE) Physics Department Universit&#233 Norbert Zongo Koudougou Burkina Faso laboratoire de Maté riaux d&#8217H&#233liophysique et Environnement (LAMHE) Physics Department Universit&#233 Nazi Boni Bobo-Dioulasso Burkina Faso

By analysing a long series of data (1996-2019), we show that solar cycle 23 was more marked by violent solar flares and coronal mass ejections (CMEs) compared to solar cycle 24. In particular, the halo coronal mass ejections associated with X-class flares appear to be among the most energetic events in solar activity given the size of the flares, the speed of the CMEs and the intense geomagnetic storms they produce. Out of eighty-six (86) X-class halo CMEs, thirty-seven (37) or 43% are highly geoeffective;twenty-four (24) or approximately 28% are moderately geoeffective and twenty-five (25) or 29% are not geoeffective. Over the two solar cycles (1996 to 2019), 71% of storms were geoeffective and 29% were not. For solar cycle 23, about 78% of storms were geoeffective, while for solar cycle 24, about 56% were geoeffective. For the statistical study based on speed, 85 halo CMEs associated with X-class flares were selected because the CME of 6 december 2006 has no recorded speed value. For both solar cycles, 75.29% of the halo CMEs associated with X-class flares have a speed greater than 1000 km/s. The study showed that 42.18% of halo (X) CMEs with speeds above 1000 km/s could cause intense geomagnetic disturbances. These results show the contribution (in terms of speed) of each class of halo (X) CMEs to the perturbation of the Earth’s magnetic field. Coronal mass ejections then become one of the key indicators of solar activity, especially as they affect the Earth.

关键词： CME Halo (X) Geoeffectivity Geomagnetic Storm Solar Flare Solar Cycle

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The inhomogeneous incompressible Hall-MHd system with only bounded density

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Science China Mathematics 2024年

作者： Jin Tan Lan Zhang laboratoire de Math′ematiques AGM UMR CNRS 8088 Cergy Paris Universit′e Center for Mathematical Sciences and department of Mathematics Wuhan University of Technology

This paper is dedicated to the global-in-time existence and uniqueness issues of solutions for the inhomogeneous incompressible Hall-magnetohydrodynamics(MHd) system with merely bounded density. In a three-dimensional case, assuming that the initial density is a small perturbation of a positive constant in the L∞norm, we prove global well-posedness for small initial velocity and magnetic fields in critical Besov spaces. Next, we consider the so-called 21/2d flows for the inhomogeneous Hall-MHd system(that is 3d flows independent of the vertical variable) and establish the global existence of strong solutions by only assuming that the initial magnetic field is small in critical spaces and the initial density is bounded and bounded away from zero. In particular, those solutions allow piecewise constant density with jumps so that a mixture of fluids can be considered. Compared with inhomogeneous incompressible Navier-Stokes equations, the new difficulties of proving these results come from the additional so-called Hall term, which endows the magnetic equation with a quasi-linear character. In order to overcome them, we reformulate the system by taking advantage of the curl form of the magnetic equation and develop some new maximal regularity estimates for the Stokes system with just bounded coefficients.

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Synthesis of P,N-2,2'-biphenyl derivatives with central chirality

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Science China Chemistry 2010年第9期53卷 1907-1913页

作者： JEAN Ludovic POULIQUEN Michael BLANCHET Jérme LASNE Marie-Claire ROUdEN Jacques laboratoire de Chimie moléculaire et Thioorganique UMR 6507 CNRS-ENSICAEN & Université de Caen-Basse Normandie6 Boulevard du Maréchal Juin14050 CaenInstitut Normand de Chimie MoléculaireMédicinale et Macromoléculaire(INC3M)

Enantiopure 2-(dicyclohexylphosphino)-1,1'-biphenyl derivatives substituted in the 2'-position by a chiral amino group were *** the compound bearing an acyclic chiral chain,the key step was a Suzuki coupling between bromobenzeneboronic acid and N-Boc-iodoaniline whereas an aromatic nucleophilic substitution allowed the introduction of a chiral pyrrolidine in the 2'-position of the biphenyl *** efficiency of the P,N-biphenyl pyrrolidine derivatives as ligands in Pd-catalyzed arylaminations compares well with that of davePhos ligand.

关键词： 3-aminopyrrolidines Suzuki coupling biphenyls chiral ligand arylamination

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