Article de recherche | UMRI 28 - Sciences Agronomiques et Génie Rural (SAGR)

Antimicrobial resistance of Escherichia coli isolated from irrigation waters in selected urban fields around Yamoussoukro lakes in Côte d'Ivoire.

This study examined the distribution of Escherichia coli (E. coli) resistant to eleven antibiotics and possible relationships among physico-chemical parameters and these resistances. It was carried out over two years during four climatic seasons in five lakes of the Yamoussoukro lake system in Côte d'Ivoire.

Auteur: Tchimonbié Messikely Anoman¹; Aka Niangoran Marie-Stéphanie Kouadio²; Dabé Doga³, Konan Samuel Ahoudjo⁴; Adolphe Zeze¹

DOI: https://doi.org/10.3126/jowe.v2020i0.31022

Article de recherche | UMRI 28 - Sciences Agronomiques et Génie Rural (SAGR)

Composition en polyphénols totaux et en tanins des feuilles de neuf variétés de Cajanus cajan (L.) Millsp. au cours du premier cycle de croissance et en fonction du mode d’exploitation

Le pois d’angole est une légumineuse fourragère et vivrière dotée de propriétés anthelminthiques dues à ses métabolites secondaires. En vue de caractériser les teneurs en composés polyphénoliques de neuf variétés au cours des stades végétatifs, une étude a été menée. Les variétés ont été semées à raison de huit lignes par variété.

Auteur: Faustin Parfait KOUTOUAN¹, Yapo Magloire YAPI², Eboua Narcisse WANDAN³, Nguessan Clément BODJI2 et Kessé Phillipe N'DA⁴

DOI: 10.4314/ijbcs.v13i2.25

Article de recherche | UMRI 28 - Sciences Agronomiques et Génie Rural (SAGR)

Anthelmintic Activity of Nine Varieties of Cajanus cajan (L.) Anthelmintic Activity of Nine Varieties of Cajanus cajan (L.) Millsp on Haemonchus contortus from Sheep

Internal parasitosis is the most important parasitism in small ruminants in tropical region. Synthetic anthelmintics are usually used for their control. Due to the emergence of resistance in worm population, the use of alternative methods such as plants bioactive molecules are developed. This study aimed at assessing anthelmintic activity of nine varieties of Cajanus cajan, a taniferous plant cultivated in West Africa.

Auteur: Faustin Parfait Koutouan^1,2, Yapo Magloire Yapi^1,3, Souleymane Kande⁴, Eboua Narcisse Wandan^1,2

DOI: 10.18805/IJAR.B-1400

Article de recherche | UMRI 38 - Mathématiques et Nouvelles Technologie de l'information (MNTI)

M-Estimate for the stationary hyperbolic GARCH models

In this manuscrit, we propose two classes ofM-estimates for the hyperbolic GARCH models. The first class called M-estimate is defined by minimizing of a convenient bounded loss function. The second, called BM-estimate is a modified version of the first with a mechanism that limits the propagation of the effect of outliers in the conditional variance.

Auteur: Lanciné Bamba¹ · Ouagnina Hili¹ · Abdou Kâ Diongue² · Assi N’Guessan³

DOI: https://doi.org/10.1007/s40300-021-00221-w

Article de recherche | UMRI 38 - Mathématiques et Nouvelles Technologie de l'information (MNTI)

NUMERICAL BLOW-UP FOR A QUASILINEAR PARABOLIC EQUATION WITH NONLINEAR BOUNDARY CONDITION

This paper is concerned with the study of the numerical approximation for the following quasilinear parabolic equation: with a nonlinear boundary condition It is shown that the solution may blow up in finite time. We first use the finite differences method in the space variable to obtain a semidiscrete scheme.

Auteur: Ganon Ardjouma, Taha M. Mathurin and Touré K. Augustin

DOI: http://dx.doi.org/10.17654/MS114010019

Article de recherche | UMRI 38 - Mathématiques et Nouvelles Technologie de l'information (MNTI)

Blow-up for Semidiscretization of Semilinear Parabolic Equation With Nonlinear Boundary Condition

This paper deals with the study of the numerical approximation for the following semilinear equation with a nonlinear absorption term u_t = u_xx− λu^p, 0 < x < 1, t > 0, and a nonlinear flux boundary condition u_x(0,t) = 0, u_x(1,t) = u^q(1,t), t > 0. We give conditions under which the positive semidiscrete solution blows up in a finite time. Convergence of the numerical blow-up time to the theoretical one when the mesh size goes to zero is established. Finally, we use an efficient algorithm to estimate the blow-up time.

Auteur: Ardjouma Ganon, Manin Mathurin Taha, Kidjégbo Augustin Touré

DOI: https://doi.org/10.5539/jmr.v11n5p1

Article de recherche | UMRI 38 - Mathématiques et Nouvelles Technologie de l'information (MNTI)

NUMERICAL BLOW-UP ON WHOLE DOMAIN FOR A QUASILINEAR PARABOLIC EQUATION WITH NONLINEAR BOUNDARY CONDITION

This paper deals with numerical approximation of the following quasilinear parabolic equation u_t = u^1+γu_xx , 0 < x < 1, t > 0, with a nonlinear boundary condition u_x(0, t) = −u^q(0, t), u_x(1, t) = 0, t > 0. We show that the solution of the semidiscrete scheme, obtained by the finite differences method blows up in a finite time when 0 < q < 1. Convergence of the numerical blow-up time to the theoretical one when the mesh size goes to zero is also established. Finally, we give some numerical results to illustrate certain point of our work.

Auteur: ARDJOUMA GANON1, MATHURIN M. TAHA, AND AUGUSTIN K. TOURÉ

DOI: https://doi.org/10.37418/amsj.9.1.5

Article de recherche | UMRI 38 - Mathématiques et Nouvelles Technologie de l'information (MNTI)

NUMERICAL BLOW-UP FOR NONLINEAR DIFFUSION EQUATION WITH NEUMANN BOUNDARY CONDITIONS

This work is concerned with the study of the numerical approximation for the nonlinear diffusion equation (u^m)t = u_xx , 0 < x < 1, t > 0, under Neumann boundary conditions u_x(0,t) = 0, u_x (1,t) = u^α(1,t), t > 0. First, we obtain a semidiscrete scheme by the finite differences method and prove the convergence of its solution to the continuous one. Then, we establish the numerical blow-up and the convergence of the numerical blow-up and the convergence of the numerical blow-up time to the theoretical one when the mesh size goes to zero. Finally, we illustrate our analysis with some numerical experiments.

Auteur: ARDJOUMA GANON1, MATHURIN M. TAHA, N'GUESSAN KOFFI AND AUGUSTIN K. TOURÉ

DOI: 10.22436/jnsa.014.02.03

Article de recherche | UMRI 38 - Mathématiques et Nouvelles Technologie de l'information (MNTI)

On nonparametric conditional quantile estimation for non-stationary random fields

A kernel conditional quantile estimate of a real-valued non-stationary spatial process is proposed for a prediction goal at a non-observed location of the underlying process. The originality is based on the ability to take into account some local spatial dependency. Large sample properties based on almost complete and Lq-consistencies of the estimator are established. A numerical study is given in order to illustrate the performance of our methodology.

Auteur: Serge-Hippolyte Arnaud KANGA ^(1,∗), Ouagnina HILI ⁽¹⁾ and Sophie DABO-NIANG ^(2,3)

DOI: http://dx.doi.org/10.16929/as/2021.3039.193

Article de recherche | UMRI 38 - Mathématiques et Nouvelles Technologie de l'information (MNTI)

Estimation in the zero-inflated bivariate Poisson model with an application to health-care utilization data

Data on the demand for medical care is usually measured by a number of different counts. These count data are most often correlated and subject to high proportions of zeros. However, excess zeros and the dependence between these data can jointly affect several utilization measures. In this paper, the zero-inflated bivariate Poisson regression model (ZIBP) was used to analyze health-care utilization data. First, the asymptotic properties of the maximum likelihood estimator (MLE) of this model were investigated theoretically. Then, a simulation study is conducted to evaluate the behaviour of the estimator in finite samples. Finally, an application of the ZIBP model to health care demand data is provided as an illustration.

Auteur: Konan Jean Geoffroy Kouakou^(1;), Ouagnina Hili⁽¹⁾ and Jean-Franc¸ois Dupuy⁽²⁾

DOI: http://dx.doi.org/10.16929/as/2021.2763.183

Article de recherche | UMRI 38 - Mathématiques et Nouvelles Technologie de l'information (MNTI)

NUMERICAL QUENCHING VERSUS BLOW-UP FOR A NONLINEAR PARABOLIC EQUATION WITH NONLINEAR BOUNDARY OUTFLUX

In this paper, we study numerical approximations for positive solutions of a semilinear heat equations, u_t = u_xx + u^p, in a bounded interval (0; 1), with a nonlinear flux boundary condition at the boundary u_x(0; t) = 0, u_x(1; t) = -u^-q(1; t). By a semi-discretization using finite difference method, we get a system of ordinary differential equations which is expected to be an approximation of the original problem. We obtain some conditions under which the positive solution of our system quenches or blows up in a finite time and estimate its semidiscrete blow-up and quenching time. We also estimate the semidiscrete blow-up and quenching rate. Finally, we give some numerical results to illustrate our analysis.

Auteur: KOUAKOU CYRILLE N’DRI, KIDJEGBO AUGUSTIN TOURÉ, AND GOZO YORO

DOI: http://dx.doi.org/10.17654/NM017340141

Article de recherche | UMRI 38 - Mathématiques et Nouvelles Technologie de l'information (MNTI)

A CLASSICAL RUNGE KUTTA METHOD OF ORDER 5

The methods of Runge-Kutta of order 5 for differential equations are very difficult to determine given the volume of equations of nonlinear systems and variables. The variable choices are the most delicate. In this article, a new approach for the determination of coefficients is introduced. This approach is based on Lagrange interpolation and allows to find some coefficients automatically. The other coefficients are determined with the shortest volume of equations.

Auteur: SÉKA HIPPOLYTE* and KOUASSI ASSUI RICHARD

DOI: http://www.pspchv.com/content_1_PJMMS_volume_27_issus-1.html

Article de recherche | UMRI 38 - Mathématiques et Nouvelles Technologie de l'information (MNTI)

A New Eighth Order Runge-Kutta Family Method

In this article, a new family of Runge-Kutta methods of 8^th order for solving ordinary differential equations is discovered and depends on the parameters b₈ and a_10,5. For b₈ = 49/180 and a_10,5 = 1/9, we find the Cooper-Verner method [1]. We show that the stability region depends only on coefficient a_10,5. We compare the stability regions according to the values of a_10,5 with respect to the stability region of Cooper-Verner.

Auteur: SÉKA HIPPOLYTE* and KOUASSI ASSUI RICHARD

DOI: http://www.pspchv.com/content_1_PJMMS_volume_27_issus-1.html

Article de recherche | UMRI 38 - Mathématiques et Nouvelles Technologie de l'information (MNTI)

A New Eighth Order Runge-Kutta Family Method

In this article, a new family of Runge-Kutta methods of 8^th order for solving ordinary differential equations is discovered and depends on the parameters b₈ and a_10,5. For b₈ = 49/180 and a_10,5 = 1/9, we find the Cooper-Verner method [1]. We show that the stability region depends only on coefficient a_10,5. We compare the stability regions according to the values of a_10,5 with respect to the stability region of Cooper-Verner.

Auteur: SÉKA HIPPOLYTE* and KOUASSI ASSUI RICHARD

DOI: 10.5539/jmr.v11n2p190

Article de recherche | UMRI 38 - Mathématiques et Nouvelles Technologie de l'information (MNTI)

ORDER OF THE RUNGE–KUTTA METHOD AND EVOLUTION OF THE STABILITY REGION1

In this article, we demonstrate through specific examples that the evolution of the size of the absolute stability regions of Runge–Kutta methods for ordinary differential equation does not depend on the order of methods.

Auteur: Hippolyte Séka, Kouassi Richard Assui

DOI: 10.15826/umj.2019.2.006

Article de recherche | UMRI 48 - Communication, Langues et Sciences Humaines (CLSH)

STRATÉGIES DE RÉSOLUTION DURABLE DES CONFLITS AGRICULTEURS - ÉLEVEURS DANS LE HAMBOL

The extent and persistence of conflicts between farmers and herders have led to the study of this phenomenon in northern Côte d’Ivoire, particularly in the Hambol Region. The main objective of our work is to propose a strategy for the sustainable resolution of these confrontations, the aim of which is to create a harmonious and peaceful living environment for the populations concerned.

Auteur: coulibaly hobonan & allagba kouassi charles

DOI: https://www.revues-ufhb-ci.org/?parcours=revues&desc=5&arti=1453

Article de recherche | UMRI 48 - Communication, Langues et Sciences Humaines (CLSH)

STRATÉGIES DE RÉSOLUTION DURABLE DES CONFLITS AGRICULTEURS - ÉLEVEURS DANS LE HAMBOL

Despite state, administrative and local government measures to regulate conflicts between farmers and herders, these clashes persist. The general objective of this research is to show the causes of this recurrence in Hambol area in order to provide a scientific basis for policy aimed at solving these problems and raising the moral and Rev. ivoir. anthropol. sociol. KASA BYA KASA, n° 48, 2021 © EDUCI 2021 97 material living conditions of the population. The data collected using the interview guide as a field investigation tool allowed for a content analysis.In sum, the injustice in the compensation of farmers, the lack of neutrality of the members of the Dispute Settlement Committee as well as corruption, account for the persistence of these disputes between farmers and herders in the Hambol Region.

Auteur: coulibaly hobonan

DOI: https://www.revues-ufhb-ci.org/?parcours=revues&desc=3&revi=9

Article de recherche | UMRI 48 - Communication, Langues et Sciences Humaines (CLSH)

FACTEURS SOCIOLOGIQUES DÉTERMINANT LA PROMOTION DES FEMMES DANS LES ENTREPRISES PRIVÉES DE LA ZONE INDUSTRIELLE DE YOPOUGON

This article focuses on the sociological factors determining the promotion of women in private companies in the Industrial Zone of Yopougon. To do this, a questionnaire survey was conducted with a sample of two hundred and fifty (250) women and interviews were conducted with thirty-one (31) employees from the four (4) selected companies. The data collected using the questionnaire and the interview guide as field investigation tools made it possible to analyze the data and also to carry out a content analysis. The results obtained show a significant contribution of the sociological factor in understanding the lack of promotion of women workers in private companies in the industrial zone of Yopougon.

Auteur: Wagnan Karidja KONE Epse KONE

DOI:

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Anaerobic mono-digestion of wastewater from the main slaughterhouse in Yamoussoukro (Côte d’Ivoire): Evaluation of biogas potential and removal of organic pollution

In Côte d'Ivoire, the rejection of wastewater into nature from slaughterhouses is an environmental problem because these agro-industries do not have any treatment system. Anaerobic mono digestion is a possibility for the treatment of slaughterhouse wastewater. The main objective of this study is to evaluate the performance of the anaerobic mono-digestion of wastewater from the main slaughterhouse in Yamoussoukro. The study was carried out using a 5 L laboratory batch reactor under mesophilic conditions (32 ± 3 °C). In the reactor wastewater was kept under constant stirring by a magnetic stirrer at a speed of 300 rpm until the biogas exhausted.

Auteur: Kouakou Eric Adou, Okon Albert Alle, Adjoumani Rodrigue Kouakou, Kopoin Adouby, Patrick Drogui, Rajeshwar Dayal Tyagi

DOI: https://doi.org/10.1016/j.jece.2020.103770

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Modelling COD Removal from Slaughterhouse Wastewater by Electrocoagulation Using Response Surface Methodology

Modeling is an indispensable tool for a better wastewater treatment strategy. However, the modelling of slaughterhouse wastewater treatment by electrocoagulation can be difficult to achieve because of the various physico-chemical mechanisms involved. It is in this context that the objective of this study was to model and optimize COD removal and electrical energy consumption by response surface methodology (RSM) during the treatment of slaughterhouse wastewater by electrocoagulation (EC). For this purpose, a full factorial design (FD) was first used to observe the effect of experimental parameters (stirring speed, pH, time and current intensity) on COD removal and energy consumption. Then, a central composite design (CCD) was performed to optimize COD removal and electrical energy consumption. The optimum conditions are obtained at the stirring speed of 871 rpm, pH = 6.83; time of 80 min and current intensity of 1.85 A. By applying these optimal conditions for the treatment, reductions of 84 ± 1.08% of COD; 93.86 ± 0.91% of BOD; 97.80 ± 0.86% of turbidity and 99.62 ± 0.12% of PO4 3- and an energy consumption of 9 KWh.m-3 were obtained. Thus, this study reveals that RSM is an effective tool for the modeling and optimization of electrocoagulation.

Auteur: Kouakou Eric Adou, Bi Gouessé Henri Briton, Ahissan Donatien Ehouman, Kopoin Adouby, Patrick Drogui

DOI: 10.11648/j.ajche.20210906.14

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Modélisation et simulation d’un panneau solaire photovoltaïque par utilisation de la fonction W de Lambert et de Matlab-Simulink

In this present paper, the model of one exponential of the photovoltaic cell is used for the reconstitution of the I-V and P-V characteristics of photovoltaic solar cells made of polycrystalline silicon. This approach is based exclusively on the manufacturer's data (three-point method : short circuit current, open circuit voltage, maximum power point). The determination of parameters (saturation current, series resistance, parallel resistance, photonic current) was done by solving a system of four equations with four unknowns and fixing the ideality factor of the diode. This allowed us to model and simulate the current-voltage and power-voltage electrical characteristics of the photovoltaic generator. We analyzed the electrical parameters of the photovoltaic generator and its optimal electrical quantities (current, voltage and power) according to meteorological variations (temperature, illumination). The expression of the current as a function of the voltage required the use of the Lambert W function.

Auteur: Bati Ernest BOYA BI, Prosper GBAHA, Mohamed Koita SAKO et Magloire Paul Ekoun KOFFI

DOI: http://www.afriquescience.net/PDF/13/5/2.pdf

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

SIZING OF AN ELECTRIC ENERGY PRODUCTION HYBRID SYSTEM

The objective of this work is the sizing of an electric energy production system mainly based on solar panels. The system is composed of a photovoltaic field and an energy storage unit (lead acid batteries, hydrogen-based energy storage unit (HESU), or hybrid storage HESU/batteries).The energy storage unit is requested when there is excess production, or to compensate for the lack of power during peak consumption. The sizing through its tools, allowed us to define solar power, size of battery pack and storage volume of hydrogen needed to meet load concerned.

Auteur: Bati Ernest Boya Bi and Prosper Gbaha

DOI: https://www.journalajst.com/sizing-electric-energy-production-hybrid-system

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Modélisation Des Composants D’un Système Hybride Panneaux Photovoltaïque – Stockage D’énergie Via L’hydrogène – Batteries

The purpose of this paper is to develop and validate mathematical models of different elements or subsystems of our hybrid power generation system. Each component is modeled as a modular block that can easily be electrically connected to other subsystems. We used the software Matlab®- Simulink R2012a for implementation of our different models. The equations used here are empirical-semi empirical equations and allowed us to model our different components to describe correctly phenomena involved. It was necessary to have data from manufacturer such as polarization curve, surface of an elementary cell, coefficient related to threshold operating parameters, auxiliary consumption parameters and gas stoichiometry. All these allowed us to build under Matlab®-Simulink, photovoltaic panels block, battery pack block, fuel cell block, electrolyzer block and all curves representing different powers produced or consumed and different gases produced or consumed.

Auteur: Bati Ernest Boya Bi, Prosper Gbaha, Magloire Paul Ekoun Koffi, Kamenan Blaise Koua

DOI: https://core.ac.uk/download/pdf/236412364.pdf

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Dimensionnement et Gestion de l’Energie au Sein d’un Système Hybride de Production d’Energie

Renewables Energies, allowing decentralized electricity production, can help to solve the problem of electrification of isolated sites where a large number of people are devoid of any energy supply. This article aims at sizing and studying the management of energy flows in a hybrid multi-source system. The energy management strategy is an algorithm that determines at each moment the sharing of power between the various components of the system. The dimensioning allowed to obtain a good overall operation and to limit the cost of the installation. The sizing tools also allowed to define the solar power and storage volume needed to meet the demand of the given load. The strategy that we present in this article is a technique of optimized management of the energy of the hybrid system studied in order to limit the losses of conversion. This strategy reduces the size of the various components such as the PV field, the battery pack, the electrolyser and the fuel cell as well as the production costs.

Auteur: Bati Ernest Boya Bi, Prosper Gbaha, Kamenan Blaise Koua, Magloire Paul Ekoun Koffi

DOI: http://dx.doi.org/10.19044/esj.2018.v14n36p260

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Étude d’un système hybride de production d’énergie

This study focuses on development of optimal sizing model based on iterative approach to optimize sizing of various components of hybrid system Photovoltaic - Hydrogen energy storage - Batteries (PV-HES-Batteries) to ensure total autonomy of system. The relationships between the powers of various components of hybrid system have been established. The photovoltaic power and dihydrogen volume storage necessary to meet user demand have been defined. A sensitivity study was carried out to determine values of electrolyser coefficient Kel and batteries coefficient Cnom to obtain better simulation results. Finally, an electrical architecture and control strategy have been implemented for better conversion and optimal energy management within the hybrid system of energy production.

Auteur: Bati Ernest BOYA BI, Kamenan Blaise KOUA, Prosper GBAHA et Ekoun Paul Magloire KOFFI

DOI: http://afriquescience.net/PDF/16/5/17.pdf

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Studies of the adsorption parameters of Gentian Violet onto Mango (Mangifera indica Lam) Shell Activated Carbons!

Two activated carbons (ACs) were prepared by chemical activation of mango shells with phosphoric acid (AC-A) or sodium hydroxide (AC-BN) at 600 °C for 2 hours. Specific surface area, surface functions, zero charge point of pH (pHzpc) and morphology of the adsorbents were also determined. With specific surfaces of 270 m2 g-1 for AC-A and 421 m2 g-1 for AC-BN, these adsorbents were used for removing Gentian violet in aqueous solution in a batch reactor stirred magnetically at a speed of 150 rpm. Thus, the contact time, the hydrogen potential of the solution, the temperature of the reaction medium and dose of the adsorbent were analyzed. The elimination of Gentian violet on both ACs was well described by a pseudo-second order kinetics with a regression coefficient close to 1 (R2 > 0.999). The Gentian violet adsorption was perfectly described by Freundlich isotherm with higher determination coefficients for AC-A (R2 > 0.99) and AC-BN (R2 > 0.98) and by pseudo-second order kinetics. The Gentian violet adsorption was characterized by a multilayer on the activated carbon surface. AC-A and AC-BN were effective in removing the Gentian violet respectively with maximum adsorption capacities of 128.04 mg g-1 and 140.65 mg g-1.

Auteur: I. A. Gouré bi, B.G.H. Briton, Y. Soro*, B.K. Yao

DOI: https://www.sciencedirect.com/science/article/abs/pii/S1385894712011187

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Removal of Gentian Violet by activated carbon from mango kernel shells

This study aims to Gentian Violet (G.V) removal using activated carbon (AC). The AC was obtained by chemical activation of mango kernel shells (Adams) with potassium hydroxide (AC-BK), at 600°C and for 2h. AC-BK has been characterized by physico-chemical analyses such as: specific surface area, zero charge point pH, surface functions and morphology. With a specific surface area of 534 m2.g-1, AC-BK was used to remove Gentian Violet (G.V) in batch mode and under magnetic stirrer at 150 rpm. Thus, the effect of contact time, initial concentration, pH and temperature of the reaction medium was studied. The maximum abatement rate for G.V was 96.5 % at temperature of 25 °C and pH = 6. Among the models discussed, the Freundlich model seems to better reflect the elimination of G.V. by AC-BK with a coefficient of determination very close to 1 (R2 > 0.99). In addition, this reaction is well fitted by pseudo-second order kinetics with a regression coefficient of 0.99. The adsorption of G.V by AC-BK is characterized by a multilayer on the surface of the AC. These results suggest that AC-BK was effective in removing of G.V with a maximum adsorption capacity of 160. 10 mg.g-1 and could therefore be tested for the remediation of dye-laden industrial effluents.

Auteur: Irié Appolinaire Gouré Bi, Horo Koné, Gouesse Henri Briton Bi, Judicaël Ano, Yaya Soro, Benjamin Kouassi Yao

DOI: http://www.chemrevlett.com/article_141593.html

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Thermal regeneration of activated carbon saturated with nitrate ions from an artisanal furnace

The present study was initiated to help the simple and less expensive regeneration of activated carbons after saturation in rural area. In order to determine a regeneration time and the number of regeneration cycles, an adsorption test was necessary. Thus, 3h and 4 cycles of carbon regeneration are obtained after evaluation of the performance, percentage and adsorption capacity after each cycle. Regeneration percentages of 71.29, 54.05, 40.40, 28.06 % and 72.6, 69.84, 64.33, 34.98 %for respective concentrations of 30± 1.2 mg/L and 55 ± 1.6 mg/L are observed. Also, the performances of activated carbon 8.5, 10, 12, 20 g/L and capacities 24.04, 19.93, 14.9 and 10.35mg/g 35.7, 34.12, 31.43 and 17.09 mg/g respectively for dry season and rainy season were necessary to fix the number of cycles. The artisanal furnace with its ease of installation and its maximum temperature of 500±2°C is suitable for the regeneration of saturated activated carbon.

Auteur: Horo Koné, Konan Edmond Kouassi, Affoué Tindo Sylvie Konan, Kopoin Adouby, Kouassi Benjamin Yao

DOI: https://dx.doi.org/10.22161/ijaems.611.1

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Comparative study of two activated carbons from Borassus aethiopum produced in electric and artisanal furnaces

The comparison of activated carbons of Borassus aethiopum produced in an electric and artisanal furnaces showed similarities and differences in their characteristics. The activated carbon produced in an electric furnace (BA-AC FE) with a specific surface area of 888 m2/g is less microporous than the activated carbon produced in an artisanal furnace (BA-AC FA) which has a specific surface area of 1431 m2/g. Also, with its BM index (IBM) of 329.5 mg/g the BA-AC FE is more macroporous than the AC-BA-Fa which has an IBM of 28.8 mg/g. This, importance of macroporosity on the AC-BA-FE allowed to obtain an abatement rate of 95.11 % of BM against 72.24 % for the AC-BA Fa. Both carbons have type IV adsorption isotherms. In view of the good characteristics of the BA-AC FA activated carbon, the water issue can be improved in rural areas by building artisanal furnaces. These will allow to produce quality activated carbon and to design carbon filters.

Auteur: Horo Koné; Affoué Tindo Sylvie Konan; Ano Judicaël; Kouassi Benjamin Yao; Patrick Drogui

DOI: https://www.researchgate.net/publication/352762822_JCBPAT_Research_Article_370_JCBPS_Section_A

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Borassus aethiopum activated carbon prepared for nitrate ions removal

This work aims to study nitrate ions removal using Borassus aethiopum activated carbon (BA-AC) in a synthetic medium. BA-AC was prepared through artisanal method in order to provide a low-cost activated carbon. Physico-chemical characterization of BA-AC has shown a high-specific surface area (1431 m2/g). Analysis of surface morphology by scanning electron microscopy, mean pore diameter (2.76 nm) and adsorption/desorption isotherm resulted in the mesoporous adsorbent. The existence of functional groups (C = O; C–H; C–OH) was highlighted by Fourier Transform Infrared spectroscopy. A percentage of 60.56% for nitrate ions at pH 4 was reached. Pseudo-second-order kinetic and Langmuir isotherm were the most suitable models to describe adsorption process. The thermodynamic study revealed that adsorption mechanism occurs spontaneously (G° < 0). Enthalpy (H° = 1.89 kJ.mol−1) and entropy (S° = 19.03 J.mol−1K−1) values indicate an endothermic process with an increase of disorder at the solid–liquid interface.

Auteur: Horo Koné, Alain Stéphane Assémian, Tagouèlbè Tiho, Kopoin Adouby, Kouassi Benjamin Yao & Patrick Drogui

DOI: https://doi.org/10.1080/23249676.2021.1947400

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Investigation of breakthrough point variation using a semi-industrial prototype packed with low-cost activated carbon for water purification

The present study was initiated to determine the limit operating conditions of a preindustrial prototype packed with Borassus Aethiopum activated carbon for water concentration - (38.48; purification in rural areas. To do this, the influence of nitrate NO3 76.61 mg/L) related to the season (dry or rainy), the flow rate (2; 3 L/min), the mass of activated carbon (260; 300; 380 g) and the height of the filter (15; 20; 25 cm) bed was evaluated. Physico-chemical characterization of the activated carbon prepared has shown a high specific surface (1434.60 m2/g ) with both micro and mesoporous pore structure. For dry season (38.48 mg/L) using Kloze model, the respective breakthrough times of 405.83, 638.38 and 956.67 min were obtained against theoretical times of 420, 630 and 945 min. As for rainy season (76.61 mg/L) predict breakthrough times 332.5, 653.33 and 952 min were found against 315, 525 and 945 obtained theoretically.

Auteur: Horo Koné, Konan Edmond Kouassi, Alain Stéphane Assémian, Kopoin Adouby, Kouassi Benjamin Yao, Patrick Drogui

DOI: https://www.jmaterenvironsci.com/Document/vol12/vol12_N2/JMES-2021-12021-Kone.pdf

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Optimisation du procédé de traitement physicochimique des effluents d’une huilerie de Côte d’Ivoire

The objective of this study is to optimize the physico-chemical treatment system for effluents from an oil mill in Côte d'Ivoire. After having characterized the raw effluents, analyzes were carried out on various samples and then coagulation-flocculation tests were finally carried out in order to determine the optimal conditions. The results show that the optimum volume concentrations of coagulant (polyaluminum chloride) are: 200, 350, 400 and 500 ml/L for pH varying respectively from 8.7-8.9; 9.7; 10.4 and 11.4. These studies carried out on the concentration of coagulant in connection with the pH allowed proposing a mathematical model that permits to predict the concentration of coagulant to be used, knowing the pH of the effluent to be treated with a 55 Afrique SCIENCE 17(2) (2020) 54 - 66 Konan Lopez KOUAME et Nogbou Emmanuel ASSIDJO correlation coefficient R2 = 0.9796. For polyacrylamide (flocculant), the different tests have shown that; for pH values ranging between 8 and 8.9 the optimal dose of flocculant is 10 mg/L. On the other hand, when the pH is ranging between 9 and 11.4, the optimal dose of flocculant is 30 mg/L. Moreover, this study has shown that; if the optimal ranges of proposed chemical reagents and the recommendations made are correctly applied, they would contribute to achieving an annual gain of 1,347,988.8 FCFA.

Auteur: Konan Lopez KOUAME et Nogbou Emmanuel ASSIDJO

DOI: https://www.afriquescience.net/PDF/17/2/5.pdf

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

OPTIMIZATION OF THE DRINKING WATER TREATMENT PROCESS OF A SUGAR PLANT STATION IN CÔTE D'IVOIRE

This article presents an optimization of the drinking water treatment process at the SUCRIVOIRE treatment station. The objective is to optimize the coagulation and flocculation process (fundamental process of the treatment of said plant) by determining the optimal dosages of the products injected and then proposes a program for calculating the optimal dose of coagulant in order to automatically determine the optimal dose of the latter according to the raw water quality. This contribution has the advantage of saving the user from any calculations; the latter simply enters the characteristics of the raw effluent using the physical interface of the program in order to obtain the optimum corresponding coagulant concentration. For the determination of the optimal coagulant doses, we performed Jar-Test flocculation tests in the laboratory over a period of three months. The results made it possible to set up a polynomial regression model of the optimal dose of alumina sulfate as a function of the raw water parameters. A program for calculating the optimal dose of coagulant was carried out on Visual Basic. The optimal doses of coagulant obtained vary from 25, 35, 40 and 45 mg/l depending on the characteristics of the raw effluent. The model obtained is:
𝐷𝑜𝑠𝑒𝑜𝑓𝑆𝐴=−2360,735+635,597𝑝𝐻+2,444𝐶𝑜𝑛𝑑+0,078𝑇𝑢𝑟𝑏−0,046𝐶𝑜𝑢𝑙+0,111𝑀𝐸𝑆−43,471𝑝𝐻2−18,778×10−3𝐶𝑜𝑛𝑑2+3,030×10−4𝑇𝑢𝑟𝑏2+0,515×10−4𝐶𝑜𝑢𝑙2−10,206×10−4𝑀𝐸𝑆2. Finally, verification tests were carried out using this model on the process. The results obtained meet the WHO drinkability standards for all parameters for a settling time of two hours.

Auteur: Konan Lopez Kouame, Nogbou Emmanuel Assidjo and André Koné Ariban

DOI: http://dx.doi.org/10.21474/IJAR01/12321

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Multiphysical Modeling of the Activated Sludge Wastewater Treatment Process

This work was the subject of the design of a multiphysics model of wastewater treatment by activated sludge in anaerobic and aerobic environments. These treatments are described the diffusion equations, and the equations of the ASM model (activated sludge model), thus making it possible to simulate the operation of the treatment system using the Comsol software. The first phase consisted of the characterization of the effluents treated in the wastewater treatment plant of an oil mill in Côte d'Ivoire. The second phase was the modeling and numerical simulations of anaerobic and aerobic digesters. These simulations gave respectively the performance of τ1 = 21.1% and τ2 = 71.7% for the anaerobic and aerobic treatment. It appears that aerobic treatments are more effective than anaerobic treatments. The third phase consisted of the coupling of the three processes which are the anaerobic, aerobic and settling treatment. To validate the model, the effluent parameters were determined experimentally. These experimental values were used to design the model. In addition, the experimental values of the COD and the quantity of sludge were compared with those of the model in order to validate the results of the model. The experimental and simulated results are almost identical, hence the validation of the model with a coefficient of performance of 𝛾𝐺=98.53%.

Auteur: Konan Lopez KOUAME, Nogbou Emmanuel ASSIDJO, Koné ARIBAN

DOI: https://jsaer.com/

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

SIMULATION EN REGIME TEMPOREL DE LA SEDIMENTATION DE PARTICULES EN SUSPENSION DANS L’EAU A SANIA_CIE

This study is part of the modeling of physicochemical treatment processes. The objective of this study is to make a temporal simulation of the decantation of suspended solids in wastewater after coagulation-flocculation. The parameters used in the design of this model are: the rate or flow of effluent entering the decanter, the pressure inside the decanter and the load of suspended solids in the water. The work was carried out on the effluents of an oil mill (SANIA-cie). In this study, simulations are performed on Comsol multiphysics. It emerges from this study that the flow entering the decanter must be low depending on the size of the basin which requires a laminar flow. The simulations carried out show that the optimum input speed is 0.1m / s, ie a flow rate of 0.006m3 / s. Moreover, a slight increase in the internal pressure is observed under the hydrostatic law. Finally, the results of the simulations show that the concentration of MES must be as high as possible at the arrival of the effluent in the settling basin approximately 20 mol / m 3. The coefficient of performance of the model is 􀇄 = 97, 43%. This makes it possible to validate the model since it provides practically the same results as the actual processing performed in said company.

Auteur: KANGA Kouakou Hermann M., YEBOUE Konan Thiéry St Urbain

DOI:https://www.riges-uao.net/volumes/numero-special/index.php

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

SIMULATION DU TRAITEMENT PAR BOUES ACTIVEES DES EFFLUENTS INDUSTRIELS EN MILIEU ANAEROBIE : CAS DE SANIA EN CÔTE D’IVOIRE

The industrialization of the world has led to an increase in the production of industrial wastewater. This constitutes a danger for the environment. However, these effluents must be treated before being released into the environment. This paper was the purpose of the design of a multiphysical model for the treatment of industrial effluents. In this paper, we presented a modeling of the treatment of industrial effluents by activated sludge in anaerobic environment. The phenomena of this processing are described by mass conservation equations, diffusion, and equations of the ASM model, thus making it possible to simulate the operation of the Comsol software system. The first phase consisted of the characterization of treated effluents in the factory of Sania-cie and the second phase consisted of modeling and simulations. To validate the model, effluent parameters were determined experimentally. These experimental values were used to design the model. Besides, the experimental values of the chemical oxygen need (COD) were compared with those of the model in order to validate the results of the model. The experimental and simulated results are almost identical, hence the validation of the model with a coefficient of performance of 𝛾=97 %. This study also showed that the optimal range of COD for the anaerobic treatment of the effluents of SANIA_cie is [1,7 ; 1,9] (kg/m³).

Auteur: Konan Lopez KOUAME et Nogbou Emmanuel ASSIDJO

DOI: https://revist.net/REVIST_35/6-ST-730.pdf

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Optimization process of organic matter removal from wastewater by using Eichhornia crassipes

This study aimed to determine the optimal conditions for organic matter removal from wastewater by Eichhornia crassipes (E.C). As a matter of fact, a complete factorial design was used to determine the effect of residence time (X1), plant density (X2) and initial chemical oxygen demand (COD) concentration (X₃) on the phytoremediation process. The process’s performance was measured on COD (Y₁), NH₄ + (Y₂) and PO₄ ^3- (Y₃), with the results indicating a reduction of 8.59–81.71% of COD (Y1); 22.53– 95.81% of NH₄ + (Y₂) and 0.54–99.35% of PO₄ ^3- (Y₃). Then, the first-order models obtained for COD, NH4 + and PO₄ ^3- removal were validated using different statistical approaches such as statistical and experimental validation. Moreover, multi-response optimization was carried out through different scenarios. On the whole, the results obtained indicated that two serial ponds are required for an optimum organic matter removal by Eichhornia crassipes. Indeed, for the first pond, a residence time of 15 days is needed with a plant density of 60 ft/m2 and an initial concentration of about 944 mg/L. The second was the same residence time as the first with similar plant density of 60 ft/m2 and an initial load 192 mg/L (> 200 mg/L). Optimal organic matter removal from wastewater using Eichhornia crassipes requires two ponds arranged in chain.

Auteur: Sènandémi Edwige Reine Mahunon, & Martin Pépin Aina & Akuemaho Virgile Onésime Akowanou & Edmond Konan Kouassi & Benjamin Kouassi Yao & Kopoin Adouby & Patrick Drogui

DOI: https://link.springer.com/article/10.1007/s11356-018-2771-y

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Elimination of Carbon, Nitrogen and Phosphorus in Domestic Wastewater through a Series of Anaerobic and Aerobic Reactors for a Developing Country like Benin

The industrialization of the world has led to an increase in the production of industrial wastewater. This constitutes a danger for the environment. However, these effluents must be treated before being released into the environment. This paper was the purpose of the design of a multiphysical model for the treatment of industrial effluents. In this paper, we presented a modeling of the treatment of industrial effluents by activated sludge in anaerobic environment. The phenomena of this processing are described by mass conservation equations, diffusion, and equations of the ASM model, thus making it possible to simulate the operation of the Comsol software system. The first phase consisted of the characterization of treated effluents in the factory of Sania-cie and the second phase consisted of modeling and simulations. To validate the model, effluent parameters were determined experimentally. These experimental values were used to design the model. Besides, the experimental values of the chemical oxygen need (COD) were compared with those of the model in order to validate the results of the model. The experimental and simulated results are almost identical, hence the validation of the model with a coefficient of performance of 𝛾=97 %. This study also showed that the optimal range of COD for the anaerobic treatment of the effluents of SANIA_cie is [1,7 ; 1,9] (kg/m³).

Auteur: Senandemi E. R. Mahunon, Akuemaho V. O. Akowanou, Martin P. Aina, Benjamin K. Yao, Dominique K. C. Sohounhloué

DOI:https://www.scirp.org/journal/paperinformation.aspx?paperid=57202

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Study of the variation in the chemical composition of Eichhornia crassipes exposed to external aggressions

Used in several areas including sanitation, water hyacinth is known for its ability to absorb pollutants which in turn represent an external aggression for the plant. This work aims to study the variation of the chemical compounds secreted by this plant to deal with external aggressions. The major families of chemical compounds were identified, according to the standard procedure, in the species of Eichhornia crassipes from two countries (Benin and Ivory Coast). The results showed the presence of several secondary metabolites (free flavonoids, polyphenols, sterols, leucoanthocyanins and terpenoids). Determination of the phenolic compounds revealed a high concentration of total flavonoids compared to tannins and polyphenols, whatever the state of the plant (fresh or dry).

Auteur:

DOI: 10.24214/IJGHC/HC/6/3/7484

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Study of the variation in the chemical composition of Eichhornia crassipes exposed to external aggressions

Used in several areas including sanitation, water hyacinth is known for its ability to absorb pollutants which in turn represent an external aggression for the plant. This work aims to study the variation of the chemical compounds secreted by this plant to deal with external aggressions. The major families of chemical compounds were identified, according to the standard procedure, in the species of Eichhornia crassipes from two countries (Benin and Ivory Coast). The results showed the presence of several secondary metabolites (free flavonoids, polyphenols, sterols, leucoanthocyanins and terpenoids). Determination of the phenolic compounds revealed a high concentration of total flavonoids compared to tannins and polyphenols, whatever the state of the plant (fresh or dry).

Auteur: Sènandémi Edwige Reine MAHUNON, Martin Pépin AINA, Edmond Konan KOUASSI, Cokou Pascal AGBANGNAN-DOSSA, Benjamin Kouassi YAO, Kopoin ADOUBY

DOI: 10.24214/IJGHC/HC/6/3/7484

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Studies on the evaporation of waxy crude oil

Spilled oil threatens groundwater resources in many parts of the world. Evaporation increases crude oildensity, viscosity and fraction of lower molecular weight substances which reduce its infiltration into the soil and groundwater. In this work, we studied the impact of wax crystallization on the evaporation rate of waxy crude oil.The characterization of this crude oil shows that it has a high wax content. To characterize its tendency towards solidification,the variation of its viscosity as a function of the temperature was measured, which shows that it is very viscous from a temperature of 40 °C, it crystallizes at 27°C. Subsequently,we determined its evaporation rate at room temperature, the change in composition by GC-FID chromatography analysis. The results indicate that wax in crude oil can greatly decrease its evaporation rate.

Auteur: Mamane Souley Abdoul Aziz, Adouby Kopoin, Ousmane Mahamane Sani

DOI: IOSR Journal of Environmental Science

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Compositional, Structural, Surface Characterizations of Natural Magnetite from Air Massif (Niger) in Relation to Its Catalytic Activity

Ferrimagnetic materials such as natural magnetite are used for practical applications because of their electronic, magnetic and catalytic properties in the degradation of organic compounds. In order to determine its physicochemical properties in relation to its catalytic activity, the natural magnetite of Ofoud Mount (Niger) is characterized by X-ray florescence (XRF), X-ray diffraction (DRX), specific surface area (BET) and Fourier transformed infrared (FTIR). The result shows an iron content of 97.09% and a specific surface area of 69.742 m2/g. The crystal structure of magnetite is cubic with lattice parameters α = β = γ = 90˚, a (Å) = b (Å) = c (Å) = 8.3740. The results of this study suggest that the natural magnetite of Ofoud Mount can be used as iron source in various fields of science despite the presence of a few impurities that can improve its catalytic activity.

Auteur: Mamane Souley Abdoul Aziz, Adouby Kopoin, Ousmane Mahamane Sani

DOI: https://doi.org/10.4236/jmmce.2020.84013

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Physicochemical Characterization of Niger Crude for Processing and Transport

Niger crude oil physic chemical properties which influence it processing and flow behavior was investigated in this study. The bulk characterization includes specific gravity, viscosity, pour point, freezing point, wax content, sulfur content, SARA fraction and the Colloidal Instability Index analyses. Results indicate that the crude oil is paraffinic, light and sweet with high wax content (24.8%).The rheological behavior studied from the viscosity variation show that it is very viscous at room temperature. This study suggest that the crude exhibits high processing (light crude) and environmental qualities (sweet crude oil) but has flow problems because of its high wax content.

Auteur: Mamane Souley Abdoul Aziz, Adouby Kopoin, Ousmane Mahamane Sani

DOI: https://engineeringjournals.stmjournals.in/index.php/JoPET/article/view/4064

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Effect of Na₂CO₃ on the Catalytic Degradation of Crude Oil–Polluted Soil by Fenton Heterogène Reaction with Natural Magnetite

Crude-oil production and transport show high soil and water pollution. The principal aim of this research is to analyze the beneficial effect of natural Na₂CO₃ on the catalytic degradation of crude oil SARA fraction by Heterogeneous Fenton Reaction with natural magnetite. Saturates Aromatics, Resins and Asphaltenes (SARA) analyses and the gas chromatograph coupled with a Flame Ionization Detector (GC-FID) were typically used to analyze the crude oil compounds and the individual n-alkane oxidation. The decomposition of H₂O₂ in the presence of this magnetite determined by titration with permanganate follows first-order kinetics in the presence of Na₂CO₃. Aromatic compounds were degraded with high efficiency; the saturate and the asphaltene fraction are expected to decrease. At the end of the experiment, the chromatogram of the unoxidized crude oil shows the loss of n-alkanes in the C1 to C13 range and the decrease of the alkanes (nC14-C32).

Auteur: Mamane Souley Abdoul Aziz, Adouby Kopoin, Ousmane Mahamane Sani

DOI: https://doi.org/10.1007/s11270-022-05682-x

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Assessment of the impact of pesticide use in urban and periurban agriculture in Abidjan, Côte d’Ivoire

Pesticides are used in agriculture for the control of pests and weedy species. Unfortunately, these chemicals are a potential risk for environment contamination and human toxicity. Market gardening soils are vulnerable to human activities because of the pesticide use. The objective of this work was to make a rapid and adequate diagnosis of the conditions of pesticide use by market gardeners. Thus, a view to assess the real impact of their use on the risk of soil pollution has been established. For this purpose, interviews and questionnaires were submitted to 243 market gardeners in Port-Bouët, Songon and Bingerville. 100% of farmers use chemical pesticides on their farms. The most pesticides used are insecticides, fungicides and herbicides. 92% of farmers have a low education level and only 4.33% of them have received a good agricultural practices training. Unsafe practices such as fraudulent use of unregistered pesticides, non-compliance with recommended rates of pesticide, the use of cotton pesticides and persistent molecules have been observed. These practices increase the risk inherent of environment pollution and vegetables.

Auteur: Perpétue MAMBE-ANI, Koffi Nouho OUATTARA, Fattoh Eric ELLEINGAND and Vincent KADJO

DOI: 10.4314/ijbcs.v13i6.32

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Determination of four pesticide residues in market garden soils at three major vegetable production sites in Abidjan and surroundings, Côte d’Ivoire

The widespread use of pesticide leads to environmental contamination, and excessive use of pesticide in market gardening could leave potentially harmful residues in soil, air and water. This study aimed at determining cypermethrin, glyphosate, carbendazim and profenofos residue concentrations in market garden soils in order to assess their possible contamination. A total of thirty five soil samples were collected from three major market garden production sites. Analyses of soil samples were performed using high performance liquid chromatography (HPLC-UV). Physicochemical properties of these soils were also characterized. The results obtained showed that four pesticide residues were detected in 79.67% of soils samples. They also indicated that the concentration of profenofos was higher than other pesticide residue concentrations. A proportion of 80% of soils contained more than one pesticide residue and glyphosate residues represented 26.95% in soils, while 25.21% of soils contained cypermethrin residues.As for profenofos, it showed high levels at a percent of 24.34%. Glyphosate and cypermethrin displayed respectively average concentrations ranging from 0.07 mg/kg±0.006 to 0.015 mg/kg ±0.012 and 0.028 mg/kg±0.02 to 0.062 mg/kg±0.053.23.47% of soil samples were contaminated with carbendazim residues at concentrations ranging from 0.007mg/kg ±0.003 to 0.012 mg/ kg±0.007. From these study outcomes, known toxicity of aformentimed molecules justifies removal of pesticide residues from market garden soils using biodegradation method.

Auteur: MAMBE-ANI Perpétue, OUATTARA Koffi Nouho, ELLEINGAND Fattoh Eric1, KOSSONOU Roland, DEMBELE Ardjouma

DOI: http://dx.doi.org/10.22192/ijarbs.2021.08.10.007

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Bivalve shells (Corbula trigona) as a new adsorbent for the defluoridation of groundwater by adsorption-precipitation

Defluoridation of groundwater was performed in a batch reactor using bivalve shell powder (BSP) as adsorbent. The physicochemical characteristics of BSP, studied by Fourier Transform Infrared, Xray Diffraction and Inductively Coupled Plasma-Optical Emission Spectrometry after dissolution, have shown that BSP was mainly composed of crystalline CaCO3 (
97.8%). The effects of pH, initial fluoride concentration, adsorbent dose and contact time on the adsorption capacity of BSP were investigated. For an initial fluoride concentration of 2.2 mg/L and with 16 g/L of BSP, after 8 hours of treatment, 27.3% were eliminated at pH 7.5 versus 68% at pH 3, highlighting the efficiency of the adsorption process. The difference in adsorption capacity as a function of pH was correlated to the pHpzc of the BSP, which was equal to 8.2. Thus, at pH below pHpzc, electrostatic attraction between the fluoride anions and the positively charged adsorbent could justify the adsorption mechanism. Fittings of experimental data have evidenced that the adsorption kinetics were of pseudo-second order whereas the adsorption isotherms were of Langmuir type. The chemical precipitation of calcium fluoride was also revealed to occur upon release of Ca2þ from partial dissolution of CaCO3 in acidic conditions.

Auteur: N’Zébo Sylvestre Yapo, Bi Gouessé Henri Briton, Sadat Aw, Laurence Reinert, Patrick Drogui & Kopoin Adouby

DOI: https://doi.org/10.1080/10934529.2021.1917937

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Potential Ecological Risk of Heavy Metals in Sediments from the Ivory Coastal Areas (Toukouzou Hozalem-Assinie)

The level and the ecological risk assessment of heavy metals were evaluated in surface sediments of 72 samples from 12 stations located in the Toukouzou Hozalem-Assinie zone along the Ivorian coast using X-ray fluorescence spectroscopy. The heavy metals contamination was assessed using pollution indices: Modified degree of contamination (mCd), potential acute toxicity (TU), and potential ecological risk index (RI). The results revealed that they are ranked in descending order: Fe>Cr>Mn>V>Zn>Ni>Pb>As>Cu>Cd and the mCd values are between 4.15 and 7.86 which reflect a high degree of contaminations. The highest total toxic units (ΣTUs) were calculated in sediment samples with Cr and Cd presenting the higher TUs compared to the rest of heavy metals and contributed the most (80%) to the overall TUs. It reveals a high potential toxicity for the marine ecosystems in the Ivorian coast. Comparison with sediment quality guidelines (TEC, PEC, PEL, and mPECq) showed that Cr, Cd, and As are 75% toxic to most species of aquatic organisms living in sediments. Potential ecological RI values indicate moderate ecological risk for Cr, considerable for As, and very high for Cd for most sites.

Auteur: Laure Emma Oura , Affoué́ Tindo Sylvie Konan3, Konan Edmond Kouassi3, Horo Koné1, Kouakou Adjoumani Rodrigue, Kouassi Benjamin Yao

DOI: 10.22607/IJACS.2021.903022

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Spatial distribution of heavy metals in sediments of the Ivory Coastal zone (Toukouzou Hozalem-Assinie) in correlation with anthropic activities

The present study aims to assess the spatial distribution of heavy metals in sediment of the ivorian coastal zone using X-ray fluorescence spectroscopy (XRF). The total average concentrations of 13 heavy metals in four seasons and six campaigns on a set of 72 samples have been obtained. Those samples were collected from 12 sites located in the Toukouzou Hozalem-Assinie region. The results revealed that they are ranked in the following decreasing order: Fe > Al > Cr > Mn > V > Zn > Ni > Pb > As > Cu > Cd > Sb > Hg. Geoaccumulation index (Igeo), enrichment factor (EF), contamination factor (CF) and pollution load Index (PLI) were used to estimate the impact of anthropogenic activities on the quality of the sediments. The values of these indices showed that sediments are highly contaminated mainly with Cd, Cr, As and are of anthropogenic origin.

Auteur: Laure Emma Oura, Konan Edmond Kouassi, Affoué Tindo Sylvie Konan, Horo Koné, Adjoumani Rodrigue Kouakou, David Boa & Kouassi Benjamin Yao

DOI: https://doi.org/10.1080/02757540.2021.2013475

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Extraction et caractérisation de cires végétales issues de Borassus aethiopum (Arecaceae) et de Mangifera indica (Anacardiaceae)

The hexane Soxhlet extraction yields of two new waxes from Borassus aethiopum (rônier) and Mangifera indica fruit (mango) were 1.40 ± 0.08% and 2.51 ± 0.04 % respectively. The kinetics of extraction shows that almost all the waxes are extracted after 4 hours of heating. The respective physico-chemical parameters for wax from Borassus aethiopum and Mangifera indica are: Melting point (78.80 ± 1.09 and 53.23 ± 1.01 °C), Acid value (7.56 ± 0.83 and 17.56 ± 0.46 mg KOH / g), Iodine value (11.68 ± 0.92 and 16.03 ± 0.50 g iodine / 100 g), Saponification value (94.05 ± 0.48 and 158.58 ± 1.03 mg KOH / g), Refractive index (1.515 and 1.475). The chemical composition of the two waxes reveals the majority presence of esters (41.23%), fatty acids (21.28%), fatty alcohols (18.35%) and ketones (09.38%) for Rônier wax and carotenoids (51.35%), esters (19.90%), sterols (14.38%) and fatty acids (08.62%) for Mango wax. On the other hand, stearic acid (39.77%), palmitic acid (26.94%), linoleic acid (16.00%) and palmitoleic acid (12.73%) as well as palmitic (33.96%) and oleic acid (25.16%) and linoleic acid (13.72%) are the major fatty acids of Borassus aethiopum and Mangifera indica respectively.

Auteur: Clovis Ossey Séka, Yaya Soro, Amian Brise Benjamin Kassi ,Sorho Siaka

DOI: https://www.proquest.com/openview/4cd2a255793933821c5a301d3e42f61f/1?pq-origsite=gscholar&cbl=2035661

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Etude comparative des caractéristiques phytochimiques des feuilles de Hyptis suaveolens avant et après extraction de l’huile essentielle

L’extraction des métabolites secondaires des feuilles de Hyptis suaveolens avant et après extraction de son huile essentielle a été réalisée par macération avec un mélange éthanol-eau (70/30 : v/v) avec des rendements respectifs de 21,25 et 27,60 %. Le fractionnement successif de l’extrait hydroalcoolique obtenu par l’hexane, le dichlorométhane, l’acétate d’éthyle, l’éthanol et l’eau a donné des rendements plus élevés des fractions après extraction (12,32-29,53 %) comparés à ceux avant extraction (9,61-34,04 %) de l’huile essentielle à l’exception des fractions hexanique et aqueuse. Le screening phytochimique de ces deux matrices végétales a révélé la présence de toutes les familles de métabolites secondaires recherchées autant avant qu’après extraction de l’huile essentielle exceptés les alcaloïdes qui sont absents après. Le dosage des flavonoïdes totaux a donné des teneurs plus importantes (2,22-46,00 mg EQ/g d’extrait) après extraction de l’huile essentielle sauf dans les fractions aqueuses où la teneur en flavonoïdes est plus élevée avant extraction de l’huile essentielle (1,95-33,33 mg EQ/g d’extrait). En revanche, la teneur en polyphénols totaux diminue de 0,40-48,33 à 0,30-45,20 mg EAG/g d’extrait avec l’extraction de l’huile essentielle hormis le cas de la fraction au dichlorométhane.

Auteur: Brahima Soumahoro, Yaya Soro, Amian Brise Benjamin Kassi, Sorho Siaka

DOI: https://www.researchgate.net/publication/350688471

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Characterization of rice, coffee and cocoa crops residues as fuel of thermal power plant in Cˆote d’Ivoire

This study presents the thermochemical characterization of rice straw, rice husk, coffee husk and cocoa pod husk. The main objective of this characterization is to determine the thermochemical properties of these crops residues to be used as fuel for a biomass thermal power plant for electricity production in rural areas of Cˆote d’Ivoire. For this purpose, samples of rice straw, rice husk, coffee husk and cocoa pod husk from Kodaya were analysed. These analyses consisted of the determination of the proximate and ultimate composition, heating value and ash composition of different residues samples. The results revealed that residues from rice, coffee and cocoa crops had moisture contents of 7.82–12.33%, volatile matter contents of 64.02–72.94%, ash contents of 8–23.7% and higher heating values ranging from 12.24 to 15.02 MJ/kg. The ashes from rice straw and rice husk are rich in silicon (64.45–74.78%) while those from the cocoa pod husk and coffee husk are rich in potassium (72.05–77.53%). Crops residues were also found to contain significant proportions of chlorine (0.02–0.3%), sulphur (0.21–0.32%) and nitrogen (0.5–3.01%). In order to protect the environment against greenhouse gas emissions from the use of fossil fuels; and to preserve natural resources for future generations, these thermochemical properties make rice, coffee and cocoa crops residues from the rural areas of Cˆote d’Ivoire a clean biofuel resource that can be exploited for the production of electricity from biomass thermal power plants.

Auteur: Desire Zinla , Prosper Gbaha , Paul Magloire E. Koffi , Blaise K. Koua

DOI: www.elsevier.com/locate/fuel

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Assessment of the energy potential of agricultural crop residues in rural areas of Côte d’Ivoire

There is significant interest in using biomass for power generation as coal continues to raise environmental concerns. Agricultural biomass residue-based energy generation has become one of the major focus areas of renewable energy in different countries around the world. This study quantifies the agricultural crop residues available like rice, coffee and cocoa in the rural areas in Côte d’Ivoire for energy generation purposes. Thereby, an assessment of the energy potential of these agricultural crop residues has been carried out. The results of this analysis reveal that the theoretical average potential and the average available biomass energy potential of these residues are 54.03 PJ and 35.63 PJ per year, respectively. Also, this abundant energy resource usually left to rot can allow the production of about 6.77 to 9.26 PJ of electricity per year distributed among the residues as follows: cocoa pod husk (54%), rice straw (34%), rice husk (11%) and coffee husk (1%). This study shows that there is important biomass energy potential for energy sustainability in Côte d’Ivoire.

Auteur: Blaise Kamenan Koua · Désiré Bi Tra Zinla · Paul Magloire Ekoun Koffi · Prosper Gbaha

DOI: https://doi.org/10.1007/s13399-021-02161-x

Article de recherche | UMRI 58 - Sciences des Procédés Chimiques Alimentaires et Environnementaux (SPCAE)

Life cycle assessment of power generation using cocoa pod husk in Côte d’Ivoire

This study assesses the environmental performance of cocoa pod husk as a fuel for a biomass power plant in Côte d’Ivoire. Methods: In this study, a life cycle assessment (LCA) is applied to identify four environmental impacts generated during the production of electrical energy. LCA assesses the environmental impact on the global warming potential of electricity production from a biomass power plant using a cocoa pod husk in Côte d’Ivoire. The greenhouse gas emissions of this electricity production are compared with those of other energy sources. Findings: The results show that the production of one kilowatt-hour results in the emission of 1.12 g SO2eq,0.28 g PO4eq., 9.91 g 1.4 DBeq. and 328.22 g CO2eq. These emissions involve acidification, eutrophication, human toxicity and global warming respectively. The sensitivity analysis showed that the transport distance has an effect on the greenhouse gas (GHG) emissions of the chain. The sensitivity analysis showed that the transport distance has an effect on the GHG emissions of the sector. Thus, GHG emissions increase with the distance travelled by the transport vehicle. The analysis identified power plant locations that would reduce GHG emissions for the production of 1 kWh of electricity. Novelty: The life cycle assessment was used to evaluate the environmental impact of various processes using crop residues for energy purposes.

Auteur: Bi Tra Désiré Zinla, Blaise Kamenan Koua, Prosper Gbaha, Paul Magloire Ekoun Koffi

DOI: https://doi.org/10.17485/IJST/v15i19.1679

Article de recherche | UMRI 68 - Génie Civil, Géosciences et Sciences Géographiques (GC-GSG)

MODÉLISATION STATISTIQUE DES DÉBITS D’ÉTIAGES ET DÉTERMINATION DE SEUILS D’ÉTIAGES DANS LE BASSIN VERSANT DE LA MARAHOUÉ (BANDAMA, CÔTE D’IVOIRE)

Auteur: ASSOKO A.V.S., KOUASSI A.M., NASSA R.A.K

DOI: https://www.asjp.cerist.dz/en/downArticle/125/17/1/115503

Article de recherche | UMRI 68 - Génie Civil, Géosciences et Sciences Géographiques (GC-GSG)

Modélisation statistique et alertes de crues dans le bassin versant de la Marahoué (Bandama, Côte d’Ivoire)

The objective of this study is to model the maximum monthly average annual flows (QMXA) in order to define a flood warning system in the catchment area of the Marahoué (Bandama) (Bouaflé hydrometric station). The methodology used is based on frequency analysis of QMXA (1961-2017) and also on the determination of flood thresholds to give early warnings. Standard laws were selected to conduct frequency analysis. It is clear from this study that the QMXA of the Marahoué have been better adjusted by the Gamma law, followed by the Weibull law finally comes the Log-normal law.The different flood thresholds were therefore assessed on the basis of the Gamma Law. It is the dalerte threshold (802 m3/s), the tolerance threshold (721.8 m3/s) and the crisis threshold (882.2 m3/s). These different thresholds constitute a dalerte system of floods from the Maraboué to Bouaflé.

Auteur: Assoko Adjoa Victoire Sandrine, Kouassi Amani Michel, and Nassa Relwindé Abdoul-Karim

DOI: http://www.ijias.issr-journals.org/

Article de recherche | UMRI 68 - Génie Civil, Géosciences et Sciences Géographiques (GC-GSG)

Modélisation statistique et alertes de crues dans le bassin versant de la Marahoué (Bandama, Côte d’Ivoire)

Auteur: Assoko Adjoa Victoire Sandrine, Kouassi Amani Michel, and Nassa Relwindé Abdoul-Karim

DOI: http://www.ijias.issr-journals.org/

Article de recherche | UMRI 68 - Génie Civil, Géosciences et Sciences Géographiques (GC-GSG)

Caractérisation hydrologique du bassin versant de la Marahoué (Bandama, Côte d’Ivoire)

This study carried out on the Marahoué (Bandama) watershed at the Bouaflé hydrometric station (Côte d'Ivoire) aims to characterize climate variability and its impact on the variations and availability of water resources in the watershed of the Marahoué (Bandama) in Ivory Coast. This characterization was based on the use of rainfall, thermometric and hydrometric (flow) data collected over the period 1961-2017. Thus, several methods were used (standard index of normalization, Lang method and Maillet's law). There is a decrease in precipitation and flow, however the temperature is rising. A low storage capacity of soil reservoirs in the Marahoué watershed (Bandama) has been demonstrated. Thus, low groundwater reserves were evaluated characterized by a low average drying off coefficient of 3,4.10-2 j-1, a short drying period of nearly a month and a low volume of water mobilized by the aquifers of 0.92 Km3.

Auteur: Amani Michel Kouassi, Adjoa Victoire Sandrine Assoko, and Koffi Eugène Kouakou

DOI: http://www.ijias.issr-journals.org/

Article de recherche | UMRI 68 - Génie Civil, Géosciences et Sciences Géographiques (GC-GSG)

Petrographic characterization of Campanian sandstones in the Termit basin (Niger): Diagenetic implication on the reservoir quality

Auteur: Neino Abdoulaye Garba, Kouakou Alphonse Yao, Moussa Harouna, and Isaac Fea

DOI: http://www.ijias.issr-journals.org/

Article de recherche | UMRI 68 - Génie Civil, Géosciences et Sciences Géographiques (GC-GSG)

Caractérisation géotechnique des Sols de Grand-Lahou et de Samo en construction routière

En Côte d’Ivoire, particulièrement au sud, la majorité des routes revêtues et non revêtues sont faites à base de ce type de sol compte tenu de sa grande disponibilité. En effet, les sables argileux se rencontrent dans le bassin sédimentaire ivoirien. Cependant, ces sols résultent d’un processus d’altération particulier sous les régions tropicales humides. De ce fait, les propriétés géotechniques de ces sols sont très variables, influencées par le climat, la géologie, et le degré d’altération [1]. En outre, la majorité des routes construites avec les sables argileux se dégradent de façon précoce. Ainsi, l’utilisation de ces sols dans la construction routière nécessite un minimum de connaissance de leurs propriétés physiques, chimiques et mécaniques. Le présent document rend compte, des principales propriétés citées ci-dessus, des sables argileux du bassin sédimentaire de la Côte d’Ivoire, notamment, les sables argileux de Samo et de Grand-Lahou. Après analyse, les résultats ont montré au plan de la granulométrie que malgré leur quantité élevée d’éléments grossiers respectivement de 66% et 50% ; ces sols renferment des matrices fines limono-argileuses susceptibles de créer des liaisons solides entre les grains. Au plan chimique, on note majoritairement trois oxydes : SiO2, Al2O3 et Fe2O3. Le rapport des oxydes (S/R), basé sur la classification de [2], des deux sols est supérieur à 2. Selon cette classification, ce sont des sols non latéritiques. Les analyses mécaniques ont montré que les échantillons présentent des densités sèches et des CBR faibles (d ≤ 2 et CBR à 95% de l’OPM ≤ 30%).

Auteur: KOUASSI Kouakou Pierre, KONIN Athanase, ATTO Yapi. D.S.R, GREHOA Abalé

DOI: 10.24214/jcbps.D.10.2.16070

Article de recherche | UMRI 68 - Génie Civil, Géosciences et Sciences Géographiques (GC-GSG)

Geotechnical characterization of Ivorian sedimentary basin soils used in road construction

Quality materials have always interested road technicians. Quality in terms of compact soils capable of withstanding the loads due to road traffic. Previous studies have shown that laterite from decomposition of the source rock, for social-economic and environmental reasons, is often used in road construction. In Côte d'Ivoire, particularly in the south, few paved and unpaved roads are made from clay sands, present in the Ivorian sedimentary basin. Analysis of the clay sands of Samo and Grand-Lahou, revealed that in terms of particle size, despite the high proportion of coarse elements in the clay sands of Samo (66%) and those of Grand-Lahou (50%); these soils contain fine silty-clay matrices capable of creating solid bonds between the grains. Chemically, there are mainly three oxides: SiO2, Al2O3 and Fe2O3. The ratio of oxides (S/R) is greater than 2. According to the classification, these are sands corresponding to non-lateritic soils. Mechanical analyzes have shown that these soils must be treated with hydraulic binders before they can be used in pavement layers.

Auteur: Pierre Kouassi and Athanas Konin

DOI: http://www.ijias.issr-journals.org/

Article de recherche | UMRI 68 - Génie Civil, Géosciences et Sciences Géographiques (GC-GSG)

ANALYSE DE L’IMPACT DES CHANGEMENTS CLIMATIQUES SUR LES LOIS STATISTIQUES D’AJUSTEMENT DES PLUIES EXTREMES CAS DE LA COTE D’IVOIRE

Cette étude porte sur l’analyse de la sensibilité des lois statistiques des extrêmes en fonction du contexte climatique. Elle s’est appuyée sur des données de pluies journalières maximales annuelles et des données de pluies annuelles collectées sur la période 1931-2010 à partir de vingt-six (26) stations pluviométriques en Côte d’Ivoire. La démarche méthodologique est basée d’une part sur la caractérisation du contexte climatique à partir de pluies annuelles D’autre part, la démarche de l’analyse fréquentielle des pluies extrêmes a été adoptée. Les résultats de la caractérisation climatique ont mis en évidence deux périodes à savoir une période humide avant 1970 (1931-2010) et une période sèche après 1970 (1971-2010). Il est constaté que la période humide est dominée par les lois de Gumbel (54%), Gamma (19%) et exponentielle (11%). Quant à la période sèche, elle est dominée par les lois Gamma inverse (38%), Gumbel (35%) et Gamma (23%). Les différentes lois statistiques des extrêmes sont donc sensibles au contexte climatique des données. Ces résultats posent le problème des normes hydrologiques calculées à partir des quantiles des lois des extrêmes dans un contexte actuel de changement climatique.

Auteur: NASSA R.A.K., KOUASSI A M., BOSSA S.J.

DOI: http://larhyss.net/ojs/index.php/larhyss/index

Article de recherche | UMRI 68 - Génie Civil, Géosciences et Sciences Géographiques (GC-GSG)

Sensitivity of Statistical Models for Extremes Rainfall Adjustment Regarding Data Size: Case of Ivory Coast

The objective of this study is to analyze the sensitivity of the statistical models regarding the size of samples. The study carried out in Ivory Coast is based on annual maximum daily rainfall data collected from 26 stations. The methodological approach is based on the statistical modeling of maximum daily rainfall. Adjustments were made on several sample sizes and several return periods (2, 5, 10, 20, 50 and 100 years). The main results have shown that the 30 years series (1931-1960; 1961-1990; 1991-2020) are better adjusted by the Gumbel (26.92% - 53.85%) and Inverse Gamma (26.92% - 46.15%). Concerning the 60-years series (1931-1990; 1961-2020), they are better adjusted by the Inverse Gamma (30.77%), Gamma (15.38% - 46.15%) and Gumbel (15.38% - 42.31%). The full chronicle 1931-2020 (90 years) presents a notable supremacy of 50% of Gumbel model over the Gamma (34.62%) and Gamma Inverse (15.38%) model. It is noted that the Gumbel is the most dominant model overall and more particularly in wet periods. The data for periods with normal and dry trends were better fitted by Gamma and Inverse Gamma.

Auteur: Relwindé Abdoul-Karim Nassa, Amani Michel Kouassi, Makouin Louise Toure

DOI: https://doi.org/10.4236/jwarp.2021.138035

Article de recherche | UMRI 68 - Génie Civil, Géosciences et Sciences Géographiques (GC-GSG)

Impacts of climate change on hydrological standards in West Africa: case of Ivory Coast

The objective of this study is to analyze the impacts of climate change on hydrological standards regarding rainfall norms (annual rains and extreme rains) and extreme rains quantiles in Ivory Coast. The study carried out was based on annual maximum daily rainfall data and annual rainfall data collected over the period 1931-2010 from twenty-six (26) rainfall stations. Firstly, the methodological approach is based on the evaluation of standards (normal and quantile) and on the other hand on their comparison from two periods with a different climatic context, such as a wet period (1931-1970) and a period dry (1971-2010). The comparison of the studied norms indicators (normal and quantile) was carried out using the matrices of the relative deviations and the binary matrices. The main results show that the norms of the wet period are higher than those of the dry period. Analysis of binary matrices of annual rainfall normals shows that 100% of the values are greater than 1%. Regarding the normals of extreme rains, 96.15% are greater than 1%. The analysis of the binary matrices of the quantiles of the annual maximum daily rainfall revealed a rate of values greater than 1% varying between 88 and 100% regardless of the return period. We can confirm the impact of climate change on hydrology standards or norms in Ivory Coast. Therefore, we need to take account in the design of drainage facilities.

Auteur: Relwindé Abdoul-Karim Nassa, Amani Michel Kouassi, Kassi Alexis Kouame and Judith Bossa

DOI: jistee.org/volume-vii-2022/

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

POWER CONTROL MECHANISM BASED ON THE ESTIMATION OF PROPAGATION LOSSES IN LTE TECHNOLOGY

Urbanization of cities is a problem for the quality of signal transmission power. Thus, the objective of this paper is to define a power control mechanism based on an estimation of the propagation losses due to obstacles (buildings, houses) in an LTE/LTE-advanced network. Our methodology focuses on a comparison between different radio propagation models that can be used in LTE/LTE-advanced technology such as: the propagation models COST 231 Walfisch- Ikegami, 3GPP, WINNERII and the one proposed by Saulis-Vitas in an urban area based on the following parameters: base station height, building height, obstacle density, mobile position, street width and carrier frequency.

Auteur: Adama Konate, Alex Akohoule, Pacôme Brou and Olivier Asseu

DOI: http://dx.doi.org/10.17654/EC023010019

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

MEASUREMENTSBASEDEVALUATION OF PATHLOSSEXPONENTS IN URBAN OUTDOORENVIRONMENTS

In wireless networks, propagation models are used to assess the received power signal and estimate the propagation channel. These models depend on the pathloss exponent (PLE) which is one of the main parameters to characterize the propagation environment. Indeed, in the wireless channel, the path loss exponent has a strong impact on the quality of the links and must therefore be estimated with precision for an efficient design and operation of the wireless network. This paper addresses the issue of path loss exponents estimation for mobile networks in four outdoor environments. This study is based on measurements carried out in four outdoor environments at the frequency of 2600 MHz within a bandwidth of 70 MHz. It evaluates the path loss exponent, and the impact of obstacles present in the environments. The parameters of the propagation model determined from the measurements show that the average power of the received signal decreases logarithmically with the distance. We obtained path loss exponents values of 4.8, 3.53, 3.6 and 3.99 for the site 1, site 2, site 3 and site 4, respectively. Clearly the density of the obstacles has an impact on the path loss exponents and our study shows that the received signal decrease faster as the transmitter and receiver separation in the dense environments.

Auteur: Akohoule Alex, Bamba Aliou, Kamagaté Aladji, KonateAdama, Oussama Tabbabi and Asseu Olivier

DOI: 10.21474/IJAR01/12556

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

Multi-Relational and Social-Influence Model for Predicting Student Performance in Intelligent Tutoring Systems(STI)

Recent studies have shown that Matrix Factorization (MF) method, deriving from recommendation systems, can predict student performance as part of Intelligent Tutoring Systems (ITS). In order to improve the accuracy of this method, we hypothesize that taking into account the mutual influence effect in the relations of student groups would be a major asset. This criterion, coupled with those of the different relationships between the students, the tasks and the skills, would thus be essential elements for a better performance prediction in order to make personalized recommendations in the ITS. This paper proposes an approach for Predicting Student Performance (PSP) that integrates not only friendship relationships such as workgroup relationships, but also mutual influence values into the Weighted Multi-Relational Matrix Factorization method. By applying the Root Mean Squared Error (RMSE) metric to our model, experimental results from KDD Challenge 2010 database show that this approach allows to refine student performance prediction accuracy.

Auteur: Kouamé Abel ASSIELOU, Cissé Théodore HABA, Tanon Lambert KADJO, Kouakou Daniel YAO, Bi Tra GOORE

DOI: https://www.researchgate.net/publication/340950038

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

Emotional Impact for Predicting Student Performance in Intelligent Tutoring Systems (ITS)

Current Intelligent Tutoring Systems (ITS) provide better recommendations for students to improve their learning. These recommendations mainly involve students’ performance prediction, which remains problematic for ITS, despite the significant improvements made by prediction methods such as Matrix Factorization (MF). The present contribution therefore aims to provide a solution to this prediction problem by proposing an approach that combines Multiple Linear Regression (Modelling Emotional Impact) and a Weighted Multi-Relational Matrix Factorization model to take advantage of both student cognitive and emotional faculties. This approach takes into account not only the relationships that exist between students, tasks and skills, but also students’ emotions. Experimental results on a set of pedagogical data collected from 250 students show that our approach significantly improves the results of Student Performance Prediction.

Auteur: Kouamé Abel Assielou, Cissé Théodore Haba, Bi Tra Gooré, Tanon Lambert Kadjo, Kouakou Daniel Yao

DOI: 10.14569/IJACSA.2020.0110728

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

A New Approach to Modelling Students’ Socio-Emotional Attributes to Predict Their Performance in Intelligent Tutoring Systems

Intelligent Tutoring Systems (ITS) are computer-based learning environments that aim to imitate to the greatest possible extent the behavior of a human tutor in their capacity as a pedagogical and subject expert. One of the major challenges of these systems is to know how to adapt the training both to changing requirements of all kinds and to student knowledge and reactions. The activities recommended by these systems mainly involve active student performance prediction that, nowadays, becomes problematic in the face of the expectations of the present world. In the associated literature, several approaches, using various attributes, have been proposed to solve the problem of performance prediction. However, these approaches have failed to take advantage of the synergistic effect of students' social and emotional factors as better prediction attributes. This paper proposes an approach to predict student performance called SoEmo-WMRMF that exploits not only cognitive abilities, but also group work relationships between students and the impact of their emotions. More precisely, this approach models five types of domain relations through a Weighted Multi-Relational Matrix Factorization (WMRMF) model. An evaluation carried out on a data sample extracted from a survey carried out in a general secondary school showed that the proposed approach gives better performance in terms of reduction of the Root Mean Squared Error (RMSE) compared to other models simulated in this paper.

Auteur: Kouamé Abel ASSIELOU, Cissé Théodore HABA, Tanon Lambert KADJO, Bi Tra GOORE, Kouakou Daniel YAO

DOI: 10.20448/journal.509.2021.83.340.348

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

Impact of Light Spectrum and PPFD on Germination and Seedling Emergence of Okra (Abelmoschus esculentus)

Light impact on many crops species and vegetables have been deeply studies these recents years and there is still some economical and technical issues to overcome. Thus the impact of light spectrum and Photosynthetic Photon Flux Density (PPFD) using Light-emitting diode (LED) on germination and seedling emergence of okra have been investigated in this study. Different light treatment have been applied to okra seeds using a factorial 3x3 design of 3 levels of light spectrum and 3 levels of PPFD; these 3 levels of light spectrum are defined by their peak wavelength at 635nm (R635), 457nm (B457), 521nm (G521) and are respectively in the red, blue and green region of the visible light spectra; levels of PPFD are 100 μmol.m-2.s-1, 200 μmol.m-2.s-1 and 300 μmol.m-2.s-1. Results show significant interactions (P < 0.01) between light spectrum and PPFD on mean germination time, mean germination rate, uncertainty of germination and seedlings emergence height. R635 show better mean germination rate (P < 0.1) and less uncertainty and dispersion (P < 0.05) than B457 and G521. Seedlings that emerged under PPFD of 300 μmol.m-2.s-1 are significantly shorter than those that emerged under 100 μmol.m-2.s-1 (P < 0.05) and 200 μmol.m- 2.s-1 (P < 0.1).

Auteur: DEGNI, Banah Florent;

DOI: http://mc.manuscriptcentral.com/LRT

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

EVALUATING THE EFFECT OF LIGHT SPECTRUM ON PHYSIOLOGY AND SECONDARY METABOLISM OF OKRA (ABELMOSCHUS ESCULENTUS) AT DIFFERENT GROWTH STAGES BY USE OF NON-INVASIVE FLUORESCENCE AND REFLECTANCE SPECTROSCOPY

We evaluate the effect of three major monochromatic light spectrums on the nutrition quality of okra leaves, by assessing flavonoids, anthocyanin, chlorophyll, carotenoid and water content; and also on stress and senescence. To achieve this, okra was grown under three different LED-based illumination of red (635.03 ± 1.33nm), green (522.27 ± 1.46nm), and blue (455.45 ± 1.80nm) for a daily light integral of 12,96molm2d1 with a 18/6-h light/dark photoperiod; the growing period was separated into three different phases of growth with each phase lasting 20 days, and studied using non-destructive UV/VIS/NIR spectroscopy. Results demonstrated that specific wavelength might regulate production of metabolites compounds to control vegetables’ quality.

Auteur: Banah Florent Degni, Cisse Théodore Haba, Wilfried Gauthier Dibi, Adolphe Yatana Gbogbo, Jérémie Thouakesseh Zoueu and Olivier Asseu

DOI: 10.17654/MT019020073

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

Effect of light spectrum on growth, development, and mineral contents of okra (Abelmoschus esculentus L.)

Influence of the light spectrum on growth, development, and nutrients contents of okra was studied by growing okra (Abelmoschus esculentus L.) under three different LED-based irradiations defined by their peak wavelength at 455.45 ± 1.80 nm (B455), 522.27 ± 1.46 nm (G522), and 635.03 ± 1.33 nm (R635), respectively in the blue, green, and red regions of the visible spectrum. The photosynthetic photon flux density (PPFD) of 200 μmolm−2 s−1 was provided by the LEDs for 18 h daily. Leaves macronutrients and micronutrients concentration and plant biometric parameters were measured 60 days after sowing; the evolution of biometric parameters was also monitored during the growing period. Results related to biometric parameters have shown that highest leaf area, plant height, and fresh and dry weight were achieved under B455 light; both R635 and G522 lights produce the highest quantity of leaves; and largest stem diameters were observed under B455 and G522 lights. Regarding mineral contents, highest calcium, phosphorus, and manganese concentrations were obtained under R635 light; highest sodium content was observed under G522 light; and the highest nitrogen content was obtained under both B455 and G522 lights. However, there were no significant differences observed for potassium, magnesium, and zinc concentrations among the three light treatments. These results revealed that selective spectrum in artificial lighting design can be strategically used to optimize the plant growth, development, and mineral contents uptake under controlled environments.

Auteur: Banah Florent Degni*, Cissé Théodore Haba, Wilfried Gauthier Dibi, Doudjo Soro, Jérémie Thouakesseh Zoueu

DOI: https://doi.org/10.1515/opag-2021-0218

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

A MECHANISM FOR DETECTING PARTIAL INFERENCES IN DATA WAREHOUSES

Data warehouses are widely used in the fields of Big Data and Business Intelligence for statistics on business activity. Their use through multidimensional queries allows to have aggregated results of the data. The confidential nature of certain data leads malicious people to use means of deduction of this information. Among these means are data inference methods. To solve these security problems, the researchers have proposed several solutions based on the architecture of the warehouses, the design phase, the cuboids of a data cube and the materialized views of multidimensional queries. In this work, we propose a mechanism for detecting inference in data warehouses. The objective of this approach is to highlight partial inferences during the execution of a multidimensional OLAP (Online Analytical Processing) SUM-type multidimensional query. The goal is to prevent a data warehouse user from inferring sensitive information for which he or she has no access rights according to the access control policy in force. Our study improves the model proposed by a previous study carried out by Triki, which proposes an approach based on average deviations. The aim is to propose an optimal threshold to better detect inferences. The results we obtain are better compared to the previous study.

Auteur: Johnson Grâce Yénin Edwige, Adepo Joel and Oumtanaga Souleymane Jérémie Thouakesseh Zoueu

DOI: 10.21474/IJAR01/12593

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

Inference Control in Aggregation Query Processing Based on Supervised Learning Models

Data warehouses are environments used for data analysis and efficient decision making within companies. They are tools that allow the execution of complex and multidimensional queries. One of the security vulnerabilities that can be used by malicious users is data inference, which is the deduction of private information by devious means. In the present work, we tried to show that the existence of functional dependencies in the data can help to perform an inference attack by using supervised learning algorithms to infer private information. These algorithms are Support Vector Machine (SVM), Random Forest (RF), Bayesian Regularized Neural Network (BRNN) and K-Nearest Neighbors (K-NN). The BRNN provided a better performance in our study. This paper implements an inference attack using regression learning algorithms, studies different dependency situations in the data, and uses the combination of COUNT, SUM, AVG and STDEV queries. The use of several methods in this study allows the prevention of inferences when one of thesemethods is used by a malicious user. We managed to achieve this attack by detecting 09.12% inferences on all methods compared to BRNN whose realized inference rate is 03.94%.

Auteur: Grâce Yénin Edwige Johnson, Joel Adepo, Beman Hamidja Kamagate, Souleymane Oumtanaga

DOI: 10.18280/isi.270301

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

Human Skeleton Detection, Modeling and Gesture Imitation Learning for a Social Purpose

Gesture recognition is topical in computer science and aims at interpreting human gestures via mathematical algorithms. Among the numerous applications are physical rehabilitation and imitation games. In this work, we suggest performing human gesture recognition within the context of a serious imitation game, which would aim at improving social interactions with teenagers with autism spectrum disorders. We use an artificial intelligence algorithm to detect the skeleton of the participant, then model the human pose space and describe an imitation learning method using a Gaussian Mixture Model in the Riemannian manifold.

Auteur: Linda Nanan Vallée, Sao Mai Nguyen, Christophe Lohr, Ioannis Kanellos, Olivier Asseu

DOI: 10.4236/eng.2020.122009

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

BUILDING AN AUTOMATED GESTURE IMITATION GAME FOR TEENAGERS WITH ASD

Autism spectrum disorder is a neurodevelopmental condition that includes issues with communication and social interactions. People with ASD also often have restricted interests and repetitive behaviors. To tackle the social interaction challenges faced by teenagers with ASD, information and communication technologies can be of help, in particulars specific artificial intelligence algorithms and interactive robots. Moreover, imitation games appear as an interesting way to explore. In this paper, preliminary bricks of an automated gesture imitation game are presented, from environment considerations to game structure, through support tools and methods, as well as body detection detailed results.

Auteur: Linda Nanan Vallée, Christophe Lohr, Sao Mai Nguyen, Ioannis Kanellos and Olivier Asseu

DOI: 10.17654/EC022020019

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

HOW AN AUTOMATED GESTURE IMITATION GAME CAN IMPROVE SOCIAL INTERACTIONS WITH TEENAGERS WITH ASD

With the outlook of improving communication and social abilities of people with ASD, we propose to extend the paradigm of robot-based imitation games to ASD teenagers. In this paper, we present an interaction scenario adapted to ASD teenagers, propose a computational architecture using the latest machine learning algorithm Openpose for human pose detection, and present the results of our basic testing of the scenario with human caregivers. These results are preliminary due to the number of session (1) and participants (4). They include a technical assessment of the performance of Openpose, as well as a preliminary user study to confirm our game scenario could elicit the expected response from subjects.

Auteur: L. N. VALLÉE*, S. M. NGUYEN, C. LOHR, I. KANELLOS, O. ASSEU

DOI: 10.48550/arXiv.2007.05394

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

Minimization of Spectrum Fragmentation for Improvement of the Quality of Service in Multifiber Elastic Optical Networks

Internet data traffic is still growing considerably in recent decades. In view of this exponential and dynamic growth, elastic optical networks are emerging as a promising solution for today's flexibly allocated bandwidth transmission technologies. The setup and release of dynamic connections with different spectrum bandwidths and data rates leads over time to spectrum fragmentation in the network. However, single-fiber eastic optical networks are faced with the problem of optical spectrum fragmentation. Spectrum fragmentation refers to small blocks, isolated, non-aligned spectrum segments which is a critical issue for elastic optical network researchers.With the advent of multifiber, this fragmentation ratio has become more pronounced, resulting in a high blocking ratio in multifiber elastic optical networks. In this paper, we propose a new routing and spectrum allocation algorithm to minimize fragmentation in multifiber elastic optical networks. In the first step, we define different virtual topologies as many as there is fiber, for each virtual topology, the k shortest paths are determined to find the candidate paths between the source and the destination according to the minimization of a proposed parameter called allocation cost. In the second step, we apply the resource allocation algorithm followed by the choice of the optimal path with a minimum energy cost. Blocking probability and spectrum utilization are used to evaluate the performance of our algorithm. Simulation results show the effectiveness of our proposed approach and algorithm.

Auteur: Boris Stephane ZOUNEME, Georges Nogbou ANOH, Souleymane OUMTANAGA

DOI: 10.14569/IJACSA.2020.0110535

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

Nouvel outil de mesure non destructive de la qualité des mangues par télédétection

Nous avons développé dans ce travail une méthode d’évaluation de la qualité des fruits basée sur la spectroscopie par télédétection passive. Utilisant la lumière solaire, un télescope couplé à un spectromètre a permis d’acquérir les spectres de réflectance de mangues présentant deux niveaux de maturité. Ces spectres ont été corrélés à l’aide de la régression PLS à des paramètres chimiques de qualité mesurés sur ces mangues à savoir : La teneur en matière soluble, le pH et la teneur en eau. Les résultats obtenus montrent d’une part que le modèle de prédiction de la teneur en sucre est réussi avec un RPD de 3,8 et une valeur de coefficient de corrélation de 0,93 en validation croisée. D’autre part, les modèles de prédiction du pH et de la teneur en eau obtenus sont acceptables avec des RPD de pH de 2,14 et RPD de la teneur en eau de 1,9. Les valeurs de coefficient de corrélation du pH et de la teneur en eau confirme la performance de ces modèles. L’utilisation de cette technique permet donc d’avoir une appréciation rapide et précise de la qualité des mangues.

Auteur: Eliane K. N. ASSOI, Wilfried DIBI, Anicet K. KOUAKOU, Benoit Kouakou KOUAKOU, Thomas KOFFI et Jérémie T. ZOUEU

DOI: http://www.afriquescience.net

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

Entomological remote dark field signal extraction by maximum noise fraction and unsupervised clustering for species identification

Characterization of flying insects in-situ measurement using remote sensing spectroscopy is an emerging research field. Also, most analysis techniques in remote sensing spectroscopy are based on the use of an intensity threshold which introduces indeterminacies in the number of detected specimens. In this manuscript, we investigated the possibility of analyzing passive remote sensing spectroscopy measurement data using the maximum noise fraction method. The results obtained show that this analysis technique can help to overcome the measurement of background noise in spectroscopic measurements.

Auteur: Benoit Kouassi Kouakou, Eliane Koko Nadine Assoi , Adolphe Yatana Gbogbo and Jeremie Zoueu

DOI: 10.20944/preprints202103.0352.v1

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

Estimating maturity by measuring pH, sugar, dry matter, water and vitamin C content of cashew apple (Anacardium occidentale) from remote spectral reflectance data using neural network

In agricultural sector, maturity is the main decision criterion for starting the harvest. This criterion is usually revealed by a number of parameters such as pH, sugar, dry matter, water and vitamin C, which are informative but technically tedious to measure. The cashew apple is the hypertrophied peduncle which is attached to the cashew nut. It is a nutritious (very juicy fruit (85 to 90% water), sweet (7 to 13% carbohydrates), acidic and vitamin C content) fruit with high therapeutic and medicinal properties. The cashew apple is used as a raw material for many industrial applications (juice and alcohol). This research was conducted as a preliminary step towards the development of a real-time remote sensing technique for assessing the quality of tropical fruits. Spectral acquisitions were carried out from intact cashew apple using optical system composed reflector coupled with spectrometer USB 4000 FL from Ocean Optics (350-1100 nm). Immediately after spectral acquisition, the samples were analyzed by using chemical methods (sugar content, dry matter content, water content, vitamin C and pH). Preprocessing treatment method, bootstrap method was required to create statistical new samples and to increase the number of samples required. This method was used to improve the predictive performance of calibration model. Statistical models of prediction were developed using an artificial neural network (ANN) method. The results obtained from the models built by ANN showed strong relationships between predicted and experimental values: (Rsquare = 0.9870, RMSE= 0.0262) for pH, (Rsquare=0.9869, RMSE=0.1392) for Sugar, (Rsquare=0.9726, RMSE=0.3333) for water content, (Rsquare=0.9703, RMSE=0.3464) for vitamin C and (Rsquare=0.9922, RMSE= 5.0304, RMSE=5.0304) for dry matter. These results confirm the potential of visible spectroscopy to predict quality parameters of cashew apples remotely and make decisions about best harvest time.

Auteur: Eliane K. Assoi, Olivier K. Bagui1, Benoit K. Kouakou, Adolphe Y. Gbogbo, Doudjo Soro, Jeremie T. Zoueu

DOI: 10.21475/ajcs.21.15.07.p3075

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

A Local Binary Pattern-Based Method for Color and Multicomponent Texture Analysis

Local Binary Patterns (LBPs) have been highly used in texture classification for their robustness, their ease of implementation and their low computational cost. Initially designed to deal with gray level images, several methods based on them in the literature have been proposed for images having more than one spectral band. To achieve it, whether assumption using color information or combining spectral band two by two was done. Those methods use micro structures as texture features. In this paper, our goal was to design texture features which are relevant to color and multicomponent texture analysis without any assumption. Based on methods designed for gray scale images, we find the combination of micro and macro structures efficient for multispectral texture analysis. The experimentations were carried out on color images from Outex databases and multicomponent images from red blood cells captured using a multispectral microscope equipped with 13 LEDs ranging from 375 nm to 940 nm. In all achieved experimentations, our proposal presents the best classification scores compared to common multicomponent LBP methods. 99.81%, 100.00%, 99.07% and 97.67% are maximum scores obtained with our strategy respectively applied to images subject to rotation, blur, illumination variation and the multicomponent ones.

Auteur: Yao Taky Alvarez Kossonou, Alain Clément, Bouchta Sahraoui, Jérémie Zoueu

DOI: 10.4236/jsip.2020.113004

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

Development of a multispectral microscopy platform using laser diode illumination for effective and automatic label-free Plasmodium falciparum detection

In this paper, we present the progress made in developing multimodal and multispectral light microscopy for label-free malaria diagnosis. Our previously developed light emitting diode (LED) illumination system was replaced by laser diodes as light sources in order to narrow the spectral bands and improve the effectiveness of the contrast function for infected blood cell detection. The acquisition system is now equipped with an algorithm for automatic field scanning and best in-focus determination. We demonstrate the potential of this platform to provide multiple investigation modalities like transmission, reflection, scattering, fluorescence, excitation, emission and polarisation. The application of this platform on malaria-infected samples has shown the effectiveness of such a system in label-free and all-optical malaria detection by allowing the possibility of using a different type of imaging set-up for the samples analysed. Also, fewer illumination sources are used to characterise malaria-infected red blood cells compared to our previous works on malaria detection using LEDs illumination sources.

Auteur: Yao T. Alvarez Kossonou* and Jérémie T. Zoueu

DOI: https://doi.org/10.1255/jsi.2020.a17

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

Modèle Binaire Local multispectral pour le diagnostic du paludisme sans coloration

Ce papier propose une extension de la technique d’analyse de la texture basée sur les Modèles Binaires Locaux (en Anglais Local Binary Pattern ; LBP), à des images multispectrales issues de frottis sanguins minces infectés par le paludisme sans ajout de colorant chimique Giemsa. Les images ont été acquises via un microscope multispectral et multimodal équipé de 13 diodes électroluminescentes (DELs) de 375 nm à 940 nm dans trois modalités d’imagerie : la transmission, la réflexion et la diffusion. L’application de notre stratégie aux images de globules rouges révèle la transmission comme étant la meilleure modalité d’imagerie pour le diagnostic du paludisme, avec 97.67% de cellules sanguines bien classées.

Auteur: Yao Taky Alvarez Kossonou, Alain Clément, Bouchta Sahraoui, Jérémie Zoueu

DOI: https://okina.univ-angers.fr/publications/ua19442

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

A New Method to Retrieve the Three-Dimensional Refractive Index and Specimen Size Using the Transport Intensity Equation, Taking Diffraction into Account

Refractive index retrieval is possible using the transport intensity equation (TIE), which presents advantages over interferometric techniques. The TIE method is valid only for paraxial ray assumptions. However, diffraction can nullify these TIE model assumptions. Therefore, the refractive index is problematic for reconstruction in three-dimensions (3D) using a set of defocused images, as diffraction effects become prominent. We propose a method to recover the 3D refractive index by combining TIE and deconvolution. A brightfield (BF) microscope was then constructed to apply the proposed technique. A microsphere was used as a sample with well-known properties. The deconvolution of the BF-images of the sample using the microscope’s 3D point spread function led to significantly reduced diffraction effects. TIE was then applied for each set of three images. Applying TIE without taking into account diffraction failed to reconstruct the 3D refractive index. Taking diffraction into account, the refractive index of the sample was clearly recovered, and the sectioning effect of the microsphere was highlighted, leading to a determination of its size. This work is of great significance in improving the 3D reconstruction of the refractive index using the TIE method.

Auteur: Marcel A. Agnero, Kouakou Konan, Alvarez T. Kossonou, Olivier K. Bagui and Jérémie T. Zoueu

DOI: https://www.mdpi.com/2076-3417/8/9/1649

Article de recherche | UMRI 78 - Electronique et Electricité appliquées (2EA)

Multi-Spectral and Fluorescence Imaging in Prevention of Overdose of Herbicides: The Case of Maize

Evaluation of the impact of herbicides on maize was done through multispectral and multi-modal imaging and multi-spectral fluorescence imaging combined with statistical methods. Spectra containing 13 wavelengths ranging from 375 nm to 940 nm were derived from multi-spectral images in transmission, reflection and scattering mode and fluorescence images obtained using high-pass filters (F450 nm, F500 nm, F550 nm, F600 nm, F650 nm) on control maize samples and maize samples treated with Herbextra herbicide were used. The appearance of the spectra allowed us to characterize the effect of the herbicide on the maize pigment concentration. The fluorescence images allowed us to track the fate of absorbed energy and through PLS-DA and SVM-DA to discriminate the two leaf categories with very low error rates for the test, i.e. 4.9% and 2% respectively. The results of this technique can be used in the context of precision agriculture.

Auteur: Anicet K. Kouakou, Adama P. Soro, Alvarez K. Taky, Koffi Patrice, Jérémie T. Zoueu

DOI: 10.4236/sar.2017.52002x

Publication scientifique | UMRI 78 - Electronique et Electricité appliquées (2EA)

Characterization and Optical Early Diagnosis by Diffuse Reflectance Spectroscopy

Diffuse reflectance spectroscopy (DRS) is a technique that illuminates the surface of the tissue and analyzes the spectrum of backscattered light, in which the signature of various biochemical species can be identified. This promising technique is established in this article for the non-invasive and in vivo characterization of the optical properties of tissues for diagnostic applications. We have introduced a new compact and inexpensive architecture for DRS based on the use of a multispectral image sensor and LEDs to obtain a diffuse reflectance signal in contact with the skin. For the proof of concept, a prototype device, involving a spectrometer coupled to an optical fiber, a microcontroller, a set of 8 LEDs and a computer, was developed, manufactured and set up. Diffuse reflectance profiles were acquired at 438.2 nm, 544.5 nm and 613.7 nm. Indeed, the spectrum of Mycobacterium ulcerans was established by this method at 256 nm and 365.2 nm. The results obtained confirm the potential of our approach for the quantitative characterization of the optical properties of tissues.

Auteur: Didier K. Yable, Laurent Canale, Pascal Dupuis, Théodore Cissé Haba, Jérémie T. Zoueu, Georges Zissis

DOI: 10.4236/opj.2022.128014