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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

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

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

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

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

Physical and Chemical Characterizations of rubber Latex Cup Bottom Oil

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Advances in Bioscience and Biotechnology 2024年第9期15卷 511-521页

作者： Kouassi Konan Edmond Abolle Abollé Aketchi Tanoé Lucien Konan Affoué Tindo Sylvie Boa David Yao Kouassi Benjamin laboratoire de Thermodynamique et Physico-chimie du Milieu (LTPCM) Unit de Formation et de Recherche Sciences Fondamentales et Appliques Universit Nangui Abrogoua Abidjan Cte dIvoire laboratoire des Procds Industriels de synthse de lEnvironnement et des Energies Nouvelles (LAPISEN) de lInstitut National Polytechnique Flix Houphout Boigny de Yamoussoukro Yamoussoukro Cte dIvoire

rubber latex is an important economic resource. However, the residues from its harvesting are thrown away, even though they contain lipids that can be recycled. This recovery of the residues from the bottom of the cup requires first and foremost their characterization. The aim of this study is therefore to determine the main physical and chemical characteristics of rubber latex cup bottom oil. Oil’s physical parameters determination shows that it has a density of 951 kg∙m−3, a kinematic viscosity of 48.57 cSt and a water content of 0.0845%. Chemical parameters, meanwhile, indicate that this cup bottom residue has a fat content of 95.96%, an acid number of 2.805 mg KOH/g and an iodine number of 92.42 g I2/100g. Therefore, rubber latex cup bottom oil can be used in the formulation of biofuels, biolubricants, paints, varnishes, alkyd resins, polishing oils, soaps, and insecticides.

关键词： rubber Latex Cup Bottoms Oil density Viscosity Characterizations

Formulation of Motor Oil from Blends of rubber Latex Cup Bottom Oil (rLBO) and Used Frying Oil (UFO)

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Journal of Sustainable Bioenergy Systems 2024年第3期14卷 35-43页

作者： Konan Edmond Kouassi Abollé Abolle Dogafolô Soro Tindo Sylvie Konan David Boa Kouassi Benjamin Yao laboratoire de Thermodynamique et Physico-chimie du Milieu (LTPCM) UFR-SFA UNA Abidjan Cte dIvoire laboratoire des Procds Industriels de synthse de lEnvironnement et des Energies nouvelles (LAPISEN) de lInstitut National Polytechnique Flix Houphout Boigny de Yamoussoukro Yamoussoukro Cte dIvoire

Most motor oils are made from mineral oils derived from petroleum, the reserves of which are limited and exhaustible. The aim of this study is to produce and characterize motor oil formulations based on mixtures of rubber latex cup bottom oil (rLCBO) and used frying oil (UFO). The results show that these formulations have a density between 0.91 and 0.92. These densities evolve linearly with the proportion of cup bottom oil and temperature. Similarly, the kinematic viscosity of the blends follows an exponential relationship with temperature. By plotting the logarithm of these kinematic viscosities against the inverse of the temperature, we were able to determine the activation energy of the various blends and deduce that the formulations behave Newtonian.

关键词： Formulation Oils Blend Motor Oils Latex Bottoms Oil

Physical Transformations on Organic Product during Its Convective Drying: Case of Sweet Potato

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Journal of Biophysical Chemistry 2024年第2期15卷 25-34页

作者： Ouoba Kondia Honoré Ganamé Abdou-Salam Compaoré Aboubakar Ibrango Abdoul Salam Bama Désiré Zougmoré Francois desmorieux Hélène laboratoire de matriaux de lHliophysique et Environnement (La.M.H.E.) Unit de Formation et de Recherche en Sciences Exactes et Appliques (UFR/SEA) Universit Nazi BONI Bobo Dioulasso Burkina Faso laboratoire des matriaux et Environnement (LA.M.E.) Unit de Formation et de Recherche en Sciences Exactes et Applique (UFR/SEA) Universit Joseph KI-ZERBO Ouagadougou Burkina Faso laboratoire de Physique et de chimie de lEnvironnement (LPCE) Ecole Doctorale Sciences et Technologie (ED-ST) Universit Joseph KI-ZERBO Ouagadougou Burkina Faso laboratoire dAutomatique et de Gnie des Procds(LAGEP) Universit Claude Bernard Lyon France

This study highlighted the physical transformation that agri-food products undergo during their drying. This transformation enormously affects the customer’s choice and the profit margin of the dried product promoter. The example of the experimental study of the potato reveals that the product continually changes its dimensions during its drying. The more the product loses its water, the more the dimensions decrease. The results initially showed that the water parameters such as mass or water content decrease according to the drying principle. The dimensions length L., width l and thickness e. decrease following a linear trend whose mathematical equations which describe them are determined using the office tool, excel. This trend has repercussions on the surface and volume parameters which in turn decreases almost linearly with the product’s water content. Note that the coefficient r2 is not always acceptable, confirming the complex nature of the behavior of organic products.

关键词： Dimensions reduction Shrinkage Index I

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

Corrective Effect of the Angle of Incidence of the Magnetic Field Intensity on the Performance (Series and Shunt resistances) of a Bifacial Silicon Solar Cell

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Energy and Power Engineering 2024年第9期16卷 313-323页

作者： Idrissa Sourabié Mahamadi Savadogo Boubacar Soro ramatou Saré Christian Zoundi Martial Zoungrana Issa Zerbo laboratoire de chimie Analytique de Physique Spatiale et nergtique (L@CAPSE) Ecole Doctorale Sciences et Technologies Universit Norbert ZONGO Koudougou Burkina Faso laboratoire denergies Thermiques renouvelables (L.E.T.rE) Ecole Doctorale Sciences et Technologies Universit Joseph KI-ZERBO Ouagadougou Burkina Faso

This article presents a three-dimensional analysis of the impact of the angle of incidence of the magnetic field intensity on the electrical performance (series resistance, shunt resistance) of a bifacial polycrystalline silicon solar cell. The cell is illuminated simultaneously from both sides. The continuity equation for the excess minority carriers is solved at the emitter and at the depth of the base respectively. The analytical expressions for photocurrent density, photovoltage, series resistance and shunt resistance were deduced. Using these expressions, the values of the series and shunt resistances were extracted for different values of the angle of incidence of the magnetic field intensity. The study shows that as the angle of incidence increases, the slopes of the minority carrier density for the two modes of operation of the solar cell decrease. This is explained by a drop in the accumulation of carriers in the area close to the junction due to the fact that the Lorentz force is unable to drive the carriers towards the lateral surfaces due to the weak action of the magnetic field, which tends to cancel out as the incidence angle increases, and consequently a drop in the open circuit photovoltage. This, in turn, reduces the Lorentz force. These results predict that the p-n junction of the solar cell will not heat up. The study also showed a decrease in series resistance as the incidence angle of the magnetic field intensity increased from 0 rad to π/2 rad and an increase in shunt resistance as the incidence angle increased. His behaviour of the electrical parameters when the angle of incidence of the field from 0 rad to π/2 rad shows that the decreasing magnetic field vector tends to be collinear with the electron trajectory. This allows them to cross the junction and participate in the external current. The best orientation for the Lorentz force is zero, in which case the carriers can move easily towards the junction.

关键词： Angle of Incidence Magnetic Field Intensity Bifacial Polycrystalline Silicon Solar Cell Series resistance Shunt resistance