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Open Journal of Civil Engineering 2024年第2期14卷 155-167页

作者： Malang Bodian Mariétou Barro Diop-Fall Dame Keinde El-Hadji Dieye Modou Gningue Diop Modou Fall laboratoire de chimie Physique organique et dAnalyse Environnementales (LCPOAE) Dpartement de Chimie Univ Cheikh Anta Diop de Dakar Dakar Senegal laboratoire de Matriaux de Gnie Civil (LMGC) Ecole Suprieure Polytechnique de Dakar Univ Cheikh Anta Diop Dakar Sngal

this work first investigates the corrosion-inhibiting behavior of montmorillonite K-10 on reinforcing steel. the corrosion-inhibiting power of the clay (Montmorillonite) is determined in a medium HCl (C = 1N) using free corrosion potential monitoring, Tafel potentiodynamic polarization curves and electrochemical impedance spectroscopy. the results of this study showed a satisfactory corrosion-inhibiting efficiency of around 72.665% for the optimum content of 1%. this is due to the presence of a stable oxide layer that protects the metal against corrosion. To validate the concept of montmorillonite as a corrosion inhibitor in repair mortar, we now turn to the influence of montmorillonite on the mechanical properties of mortars in the hardened state. In this part, montmorillonite K-10 is added to the mortar by partial substitution of the cement by 5% and 10% of the cement mass. the aim of this study is to ensure that the addition of this clay to the mortar composition will not have a negative effect on its compressive and flexural strengths. the results of the compression and flexural tests showed that the presence of montmorillonite in the mortar improved flexural and compressive strengths for the different compositions studied.

关键词： Clay Reinforced Concrete Corrosion Inhibitor Rehabilitation Electrochemical Methods

Phytochemical Screening and Assays of Phenolic Compounds in Senna occidentalis L. Leaf and Seed Extracts

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Food and Nutrition Sciences 2024年第7期15卷 499-508页

作者： Edmond Antoine Badock Lahat Niang Abdoulaye Dramé Célestine Nkounkou-Loumpangou Omar Touré Omar Sokhna Nicolas Cyrille Ayessou Mady Cissé Ecole Suprieure Polytechnique Laboratoire Eau Energie Environnement et Procds Industriels (LE3PI) Universit Cheikh Anta Diop Dakar Sngal Ecole Suprieure Polytechnique Centre dEtudes sur la Scurit Alimentaire et les Molcules Fonctionnelles (CESAM-RESCIF) Universit Cheikh Anta Diop Dakar Sngal laboratoire de Valorisation des Produits de la Biomasse Dpartement de Chimie Universit Cheikh Anta Diop de Dakar Dakar Sngal Unit de chimie du Vgtal et de la Vie Facult des Sciences et Techniques Universit Marien NGOUABI Brazzaville Republic of the Congo laboratoire de chimie organique et Bio-organique Dpartement de Chimie Facult des Sciences et Techniques/UCAD Universit Cheikh Anta Diop Dakar Sngal

Phytochemical screening and assay of secondary metabolites, crude extracts with distilled water, aqueous methanol, aqueous acetone and aqueous ethanol of leaves and seeds of Senna occidentalis L. were studied in this work. the aim was to verify the distribution of secondary metabolites according to S. occidentalis organs. Four leaf samples from four different localities (South, East, West and Central Senegal) and a mixed sample of seeds were used. Functional molecules such as polyphenols, flavonoids and tannins were then assessed in the leaves and seeds using various standard methods. the results show that Senna occidentalis L. leaf and seed samples display an identical and homogeneous profile, regardless of locality. they contain secondary metabolites and the polyphenol content of extracts from southern, eastern, western and central leaves is: 0.620 - 0.539 - 0.811 - 0.573 g GAE/100 g DM;flavonoids: 0.064 - 0.074 - 0.130 - 0.101 g CE/100 g DM and tannins: 0.326 - 0.264 - 0.269 - 0.494 g TAE/100 g DM. the efficacy of S. occidentalis L. infusions in therapy is thus justified by the presence of these metabolites, whose biological properties are well known. It is then possible to explore isolation of active principles of Senna occidentalis L. leaves and even seeds for producing medicines.

关键词： Senna occidentalis L. Total Polyphenols Flavonoids Tannins

Application of in-situ characterization techniques in modern aqueous batteries

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Rare Metals 2024年第8期43卷 3553-3575页

作者： Jia-Hao Wu Hong-Wei Cai Zhao-Hui deng Jean-Jacques Gaumet Yu Bao Wen Luo department of Physics State Key Laboratory of Advanced Technology for Materials Synthesis and ProcessingSchool of Materials Science and EngineeringWuhan University of Technology laboratoire de chimie et Physique:Approche Multi-Echelles Des Milieux Complexes (LCP-A2MC)Institut Jean Barriol Université de Lorraine department of Medicinal Chemistry Hubei College of Chinese Medicine

the development of high-performance aqueous batteries calls for an in-depth knowledge of their chargedischarge redox and failure mechanism,as well as a systematic understanding of the dynamic evolution of microstructure,phase composition,chemical composition,and local chemical environment of the materials for ***-situ characterization technology is expected to understand and reveal the problems faced by aqueous rechargeable batteries,such as the dissolution of electrode materials,the growth of metal negative electrode dendrites,passivation,corrosion,side reactions and a series of *** on this,typical in-situ characterization techniques and their basic mechanisms are summarized,including in-situ optical visualization,in-situ microscopy techniques(in-situ scanning electron microscopy(SEM),in-situ transmission electron microscopy(TEM)),in-situ X-ray techniques(in-situ X-ray diffraction(XRD),in-situ X-ray photoelectron spectroscopy(XPS),in-situ near-edge structural X-ray absorption spectroscopy(XANES)),and in-situ spectroscopy techniques(in-situ Raman spectroscopy,in-situ Fourier transform infrared(FTIR)).Moreover,some emerging techniques concerning aqueous battery research,especially gas evolution and materials dissolution issues,such as in-situ electrochemical quartz crystal microbalance(EQCM).in-situ fiber-optic sensing,in-situ gas chromatography(GC) are *** last,the applications of advanced in-situ characterizations in future research of aqueous batteries are emphasized and discussed,along with some of the remaining challenges and possible solutions.

关键词： Aqueous battery In-situ characterization Phase transformation Solid electrolyte interphase Zinc dendrite growth

Indirect Electroanalysis of 3-Methyl-4-Nitrophenol in Water Using Carbon Fiber Microelectrode Modified with Nickel Tetrasulfonated Phthalocyanine Complex

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Materials Sciences and Applications 2024年第2期15卷 25-35页

作者： Yibor Fabrice Roland Bako Serge Foukmeniok Mbokou Boukaré Kaboré Issa Tapsoba Maxime Pontié laboratoire de chimie Analytique Environnementale et Bio-organique (LCAEBiO) Département de Chimie Université Joseph Ki-Zerbo Ouagadougou Burkina Faso Institut des Sciences et de Technologie Ecole Normale Supérieure Ouagadougou Burkina Faso Group of analysis and Processes Analysis (GA&P) Département de Chimie Université d’Angers Angers France laboratoire de Sciences et Technologies (LaST) Université Thomas SANKARA Ouagadougou Burkina Faso

Electrochemical detection of 3-methyl-4-nitrophenol (MNP) in direct phenol oxidation occurs at high potentials and generally leads to progressive passivation of the electrochemical sensor. this study describes the use of a carbon fiber microelectrode modified with a tetrasulfonated nickel phthalocyanine complex for the detection of MNP at a lower potential than that of direct phenol oxidation. the MNP voltammogram showed the presence of an anodic peak at -0.11 V vs SCE, corresponding to the oxidation of the hydroxylamine group generated after the reduction of the nitro group. the effect of buffer pH on the peak current and SWV parameters such as frequency, scan increment, and pulse amplitude were studied and optimized to have better electrochemical response of the proposed sensor. With these optimal parameters, the calibration curve shows that the peak current varied linearly as a function of MNP concentration, leading to a limit of detection (LoD) of 1.1 μg/L. these results show an appreciable sensitivity of the sensor for detecting the MNP at relatively low potentials, making it possible to avoid passivation phenomena.

关键词： 3-Methyl-4-Nitrophenol Carbon Fiber Microelectrode Nickel Tetrasulfonated Phthalocyanine Indirect Electroanalysis Square Wave Voltammetry

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

A study on wildfire impacts on greenhouse gas emissions and regional air quality in South of Orléans,France

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Journal of Environmental Sciences 2024年第1期135卷 521-533页

作者： Chaoyang Xue Gisèle Krysztofiak Yangang Ren Min Cai Patrick Mercier Frédéric Le Fur Corinne Robin Benoit Grosselin Véronique Daele Max RMcGillen Yujing Mu Valéry Catoire Abdelwahid Mellouki laboratoire de Physique et chimie de l’Environnement et de l’Espace(LPC2E) CNRS–UniversitéOrléans–CNES(UMR 7328)Orléans Cedex 245071France Institut de Combustion AérothermiqueRéactivitéEnvironnement(ICARE)CNRSOrléans Cedex 245071France Research Centre for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Lig’Air-Association de surveillance de la qualitéde l’air en région Centre-Val de Loire Saint-Cyr-en-Val 45590France Mohammed V University RabatMorocco

Wildfire events are increasing globally which may be partly associated with climate change,resulting in significant adverse impacts on local,regional air quality and global *** September 2020,a small wildfire(burned area:36.3 ha)event occurred in Souesmes(Loiret-Cher,Sologne,France),and its plume spread out over 200 km on the following day as observed by the MODIS *** on measurements at a suburban site(~50 km northwest of the fire location)in Orléans and backward trajectory analysis,young wildfire plumes were *** increases in gaseous pollutants(CO,CH_(4),N_(2)O,VOCs,etc.)and particles(including black carbon)were found within the wildfire plumes,leading to a reduced air *** factors,defined as EF(X)=ΔX/ΔCO(where,X represents the target species),of various trace gases and black carbon within the young wildfire plumes were determined accordingly and compared with previous *** in the ambient ions(such as ammonium,sulfate,nitrate,chloride,and nitrite in the particle-and gasphase)and aerosol properties(e.g.,aerosol water content,aerosol p H)were also quantified and ***,we estimated the total carbon and climate-related species(e.g.,CO_(2),CH_(4),N_(2)O,and BC)emissions and compared them with fire emission *** biomass burning emission inventories have uncertainties in estimating small fire burned areas and *** instance,we found that the Global Fire Assimilation System(GFAS)may underestimate emissions(e.g.,CO)of this small wildfire while other inventories(GFED and FINN)showed significant *** that it is the first time to record wildfire plumes in this region,related atmospheric implications are presented and discussed.

关键词： Wildfire Air quality Emission factor Emission inventory VOLTAIRE supersite

Phytochemical Analysis and Antimicrobial Activity of Lawsonia inermis Leaf Extracts from Burkina Faso

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American Journal of Plant Sciences 2024年第7期15卷 552-576页

作者： Ollo Youl Soumaïla Konaté Ernest N. Sombié Rainatou Boly Boukaré Kaboré Moumouni Koala Arouna Zoungrana Saybou Savadogo Christian Marc Tahita Innocent Valea Halidou Tinto Adama Hilou Maminata Traoré-Coulibaly laboratoire de Biochimie et de chimie Applique (LABIOCA) Universit de Ouagadougou Ouagadougou Burkina Faso Agence Nationale Pour la Scurit Sanitaire de lEnvironnement de lAlimentation du Travail et des Produits de Sant (ANSSEAT) Ouagadougou Burkina Faso laboratoire de Recherche-Dveloppement de Phytomdicaments et Mdicaments (L-RD/PM) Institut de Recherche en Sciences de la Sant (IRSS-CNRST) Ouagadougou Burkina Faso laboratoire de chimie organique et de Physique Applique (LCOPA) cole Doctorale Sciences et Technologie Universit Joseph KI-ZERBO Ouagadougou Burkina Faso laboratoire Sciences de la Vie et de la Terre (LASVT) cole Doctorale Sciences et Technologie Universit Norbert ZONGO Koudougou Burkina Faso Unit de Recherche Clinique de Nanoro Institut de Recherche en Sciences de la Sant (IRSS-CNRST) Nanoro Burkina Faso

Lawsonia inermis is a hairless plant growing in various regions of North Africa, the Indian subcontinent, and the Middle East. It possesses many medicinal attributes, including curative properties against infectious dermatoses. this study was carried out to evaluate the phytochemical profile of the crude ethanolic extract of the plant leaves and its fractions as well as their antimicrobial activities. the phytochemical profile was performed using high-performance thin-layer chromatography (HPTLC), gas chromatography-mass spectrometry (GC-MS), and high-performance liquid chromatography (HPLC). Additionally, the phenolic and flavonoid contents were determined using the Folin-Ciocalteu spectrophotometric and the aluminum trichloride methods. Antimicrobial activity was tested using disc diffusion and microdilution methods. the presence of flavonoids, tannins, sterols, and triterpenes was revealed. GC-MS detected twelve compounds main compounds consisting of saturated and unsaturated fatty acids and phenolic and terpenoid compounds among twenty-seven components. HPLC also detected high contents of phenolic acids and flavonoids. the most abundant triterpene and sterols were ursolic acid (around 43.14 g/100g DW, 13.9 g/100g dry weight (DW), and 0.68 g/100g DW) in the crude ethanolic extract of leaves (FeLi), hexane fraction (FHLi) and dichloromethane fraction (FDLi), respectively and, β-sitosterol in FeLi (56.7 mg/100g DW), FHLi (10.55 g/100g DW), FDLi (106.1 mg/100g DW) and butanol fraction (FBLi) (357.4 mg/100g DW). Among the flavonoids, rutin = 3.24 g/100g and quercetin = 0.63 g/100g in the ethanolic extract, rutin = 15.73 g/100g in the dichloromethane fraction, and rutin = 0.23 g/100g) in the aqueous fraction;and among phenolic compounds, caffeic acid (37.65 g/100g DW) and vanillic acid (22.70 g/100g DW) were the most important in the ethyl acetate fraction (FAeLi). All organic fractions exhibited interesting antibacterial and antifungal activities against the tested s

关键词： Lawsonia inermis Phytochemical Profile HPLC GC-MS Analysis Antimicrobial Activity

Human Eosinophil Cell Manipulation by Optical Tweezers

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Open Journal of Biophysics 2024年第3期14卷 330-338页

作者： Pavel Yale Jean Michel Edoukoua Konin Abadê Ange-Boris N’guessan Michel Abaka Kouacou Jérémie T. Zoueu laboratoire dInstrumentation Image et Spectroscopie (L2IS) Institut National Polytechnique Houphout-Boigny (INPHB) Yamoussoukro Cte dIvoire laboratoire de chimie et de Physique Appliques Sciences et Techniques Universit Alassane Ouattara Bouak Cte dIvoire

In this work, lateral deformation of human eosinophil cell during the lateral indentation by an optically trapped microbead of diameter 4.5 µm is studied. the images were captured using a CCD camera and the Boltzmann statistics method was used for force calibration. Using the Hertz model, we calculated and compared the elastic moduli resulting from the lateral force, showing that the differences are important and the force should be considered. Besides the lateral component, the setup also allows us to examine the lateral cell-bead interaction. the mean values of the properties obtained, in particular the elastic stiffness and the shear stiffness, were Eh = (37.76 ± 2.85) µN/m and Gh = (12.57 ± 0.32) µN/m. these results show that the lateral indentation can therefore be used as a routine method for cell study, because it enabled us to manipulate the cell without contact with the laser.

关键词： Optical Tweezers Human Eosinophil Cell Indentation Shear Stiffness

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

the Essential Oil of Ocimum americanum from Senegal and Gambia as a Source of Methyleugenol for the Control of Bactrocera dorsalis, Fruit Fly

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Journal of Agricultural Chemistry and Environment 2024年第1期13卷 133-141页

作者： Yoro Tine Antonio Alain Coffi Sinzogan Ousmane Ndiaye Cebastiana Sambou Alioune Diallo Ismaila Mbenga Kemo Badji El Hadji Omar Dieng Assa Balayara Jeanne Diatta Cheikhouna Gaye Julien Paolini Jean Costa Alassane Wele Saliou Ngom laboratoire de chimie organique et thérapeutique Faculté de Médecine Pharmacie et Odontologie Université Cheikh Anta Diop Dakar Sénégal Faculte des Sciences Agronomiques Universite d’Abomey Calavi Cotonou Benin Ecole Nationale Supérieure d’Agriculture (ENSA) Université Iba Der Thiam de Thiès Thiès Sénégal Direction de la Protection des Végétaux Rufisque Sénégal laboratoire de chimie des Produits Naturels Université de Corse Corte France National Agricultural Research Institute (NARI) Sere Kunda Gambia Institut Sénégalais de Recherches Agricoles (ISRA) Dakar Sénégal

the fruit fly, Bactrocera dorsalis (Diptera: Tephritidae) is one of the most important pests in all mango-producing areas, particularly in West Africa. In Senegal, O. americanum leaves have been used for several years to control this fly. However, to our knowledge, no chemical studies have been carried out. thus, the aim of this study is to determine the chemical composition of the essential oil of O. americanum leaves collected in Senegal and Gambia. the essential oil obtained by hydrodistillation of these leaves is analyzed by GC/FID and GC/MS. Yields of essential oils from O. americanum leaves are 3.84% and 2.13%, respectively. Analysis of these essential oils by GC/FID and GC/MS allowed the identification of 23 compounds representing almost 100% of the total compositions. these essential oils are mainly dominated by methyleugenol (72.0% and 75.8%, respectively). Other components in significant percent are trans-β-caryophyllene (13.9% and 13.0%, respectively), germacrene D (4.1% and 3.7%, respectively), β-elemene (3.3% and 0.9%, respectively). Due to the high methyleugenol content, this study explains the attractive potential of O. americanum towards B. dorsalis. In perspective, we plan to evaluate the attractive effect of the essential oil and leaf powder of O. americanum against B. dorsalis, a real pest of mango orchards in Senegal.

关键词： Ocimum americanum Essential Oils Methyleugenol Bactrocera dorsalis GC/MS