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Influence of the Granular class of Crushed Granites on the Litho-Stabilization of Samo Laterites (South-East of Côte d’Ivoire)

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Open Journal of Civil Engineering 2023年第3期13卷 540-553页

作者： Abalé Martial Grehoa Conand Honoré Kouakou koffi clément kouadio Souleymane Ouattara Aka Alexandre Assande Edjikémé Emeruwa Laboratoire des Eaux du Sol et des Géomatériaux UFR-STRM University Félix Houphou&#235t Boigny Abidjan C&#244te d’Ivoire

Most of the laterites found in Ivory Coast do not meet the technical conditions to be used in their natural state for the design of road foundations. Also, to meet the growing needs for road materials, various amendments are made to them, including litho-stabilization. Thus, this study proposes to understand the influence of the granular class of natural aggregates on the performance of laterites. To achieve this objective, different proportions of crushed granites of class 0/5, 0/15 and 5/15 have been incorporated into the soils of southern Côte d’Ivoire, especially in Samo. This modified soil has been subjected to mechanical tests such as the modified Proctor and CBR test. The results obtained show that the dry densities of the incorporated laterites containing crushed granites increase with the content of natural aggregates and decrease with the increase in the water content. Likewise, the CBR bearing indices at 95% of the Modified Optimum Proctor of the different compositions (laterites + crushed granites) increase with the proportion of aggregates. The addition of coarse aggregates to the laterites therefore promotes the establishment of a framework which improves its bearing capacity. From 20% to 30% crushed granites respectively of class 0/15;0/5 and 5/15, the values of the CBR obtained are greater than those of 30% therefore these modified soils can be used as a foundation layer for traffic of T1, T2 and T3 type. Likewise, the laterites’ mixtures with at least 40% crushed granites of class 0/15 and 0/5 can also be used for the foundation and base layers.

关键词： Laterite Litho-Stabilization Natural Aggregate Coarse Aggregate CBR Modified Proctor Incorporated Laterites

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Development of a Composite Material Based on Wood Waste Stabilized with Recycled Expanded Polystyrene

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Open Journal of Composite Materials 2020年第3期10卷 66-76页

作者： Serge Pacome Kaho koffi clément kouadio Conand Honoré Kouakou Edjikémé Eméruwa Laboratoire de Géomatériaux UFR STRM Université Félix Houphou&#235t Boigny Abidjan C&#244te d’Ivoire

Environmental pollution is a whole world concern. One of the causes of that pollution is the proliferation of plastic waste. Among these wastes there is expanded polystyrene (EPS), mainly from packaging. This study aims to valorize EPS waste by developing a composite material from EPS waste and wood waste. For this purpose, a resin made of EPS has been elaborated by dissolving EPS in acetone. That resin was used as a binder in volume proportions of 15%, 20%, 25% and 30% to stabilize the samples. Some of them were thermoformed. The method of elaboration was based on a device consisting of an extruder for mixing the constituents, and a manual press for shaping and compacting the samples. Analyses show that the drying time depends on the composition of the mixture. Increasing the resin content leads to reduce water absorption and porosity of the samples;it also contributes to homogenize the internal structure of the samples. However, for the same resin contents, the thermoformed samples are less porous;they have more homogeneous internal structure;and absorb less water than non-thermoformed samples.

关键词： Expanded Polystyrene Wood Waste Resin Composite Material Thermoforming

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Use of Alternative Binder: Influence of Latex Content on Physical and Mechanical Properties of Laterite Stabilized with Raw Rubber Latex

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Geomaterials 2020年第3期10卷 56-65页

作者： koffi clément kouadio Owochi Quentin Aristide Offo Conand Honoré Kouakou Edjikémé Emeruwa Laboratoire de Géomatériaux Université Felix Houphou&#235 t-Boigny Abidjan C&#244 te d’Ivoire

Raw rubber Latex contents, from 0% to 30% were used to stabilize lateritic samples to provide an alternative to cement stabilization. These samples were submitted to physical tests (water resistance test, absorption test) and mechanical tests (dry compressive strength test). The results indicate that samples made of latex content less than 15% dissolve completely into water. So it was impossible to make sample with these contents. Samples with 15% of raw rubber content or more are steady after water resistance test. The absorption rate of these samples decreases as the latex content increases. It goes from 14.45% for the samples at 15% to 5.87% for those at 30%. Therefore, the compressive strength test indicates that the resistance increases from 0.37 MPa for samples without latex to 3.15 MPa for those at 30% of latex content. Also, the rheological study shows that the samples pass from a brittle behaviour to a plastic behaviour when the latex content increases. The behaviour of the sample according to these different tests shows that this material can be used in several activity areas, such as construction, road building and sports area.

关键词： Laterite Raw Rubber Latex Sample Stabilization Characterization

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Influence of a Mineral Filler on the Fire Behaviour and Mechanical Properties of a Wood Waste Composite Material Stabilized with Expanded Polystyrene

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Open Journal of Applied Sciences 2020年第12期10卷 834-843页

作者： koffi clément kouadio Brahiman Traoré Serge Pacome Kaho Conand Honoré Kouakou Edjikémé Emeruwa Laboratoire du sol de l’eau et de Géomatériaux (UFR-STRM) Université Felix Houphouet-Boigny Abidjan Cote d’Ivoire

The use of vegetable fibers composites in structures sometimes presents significant fires risks because of their high flammability. This work aims to study the impact of the addition of mineral filler (clay) on the fire behaviour of wood-polystyrene composites and their mechanical properties. Thus, composites containing 25% of expanded polystyrene binder have been produced. On this base material, proportions of clay ranging from 0% to 15% were gradually added. These samples were elaborated by compaction and for some them, submitted to thermoforming after drying. Both kinds of sample were subjected to flame persistence test;flexural strength and compressive strength test were also measured. The results show that composites without mineral filler ignite continuously until the total consumption and when the mineral filler content increases the combustion time decreases. The addition of the mineral filler allows these composites to pass from class M3 of moderately flammable combustible materials to class M2 of hardly flammable materials, according to the M classification of construction and furnishing materials. The measurement of the mechanical properties shows that the strengths increase when the filler content goes from 0% to 10% and then decrease. This leads to set the optimum content of mineral filler around 10%.

关键词： Composite Expanded Polystyrene Flame Test Flammability Mechanical Properties

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Effect of Sand Partial Substitution for Glass Powder on the Behaviour of Sand-Cement Mortar

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Materials Sciences and Applications 2019年第12期10卷 756-767页

作者： Séraphin Agré Djomo Conand Honoré Kouakou koffi clément kouadio Moro Olivier Boffoue Edjikémé Emeruwa Departement Sciences de la Terre UFR Environnement Universite Jean Lorougnon Guede Daloa Côte d’Ivoire Laboratoire de Géomatériaux et Technologie du Bâtiment (LGTB) UFR des Sciences de la Terre et des Ressources Minières Université Felix Houphouet Boigny de Cocody Abidjan Côte d’Ivoire

Partial substitution of aggregates for pieces of glass in concrete contributes to reducing the use this resource and preserving the environment for future generations. However, concretes or mortars mixed with crushed glass can deteriorate within a few years, because of the alkali-silica reaction related to the size of glass pieces. Some investigations were carried out in order to find out how to bring down this phenomenon. Different percentages of glass powder were mixed with mortar made from sand, cement and crushed glass pieces of which diameter is between 1 and 5 mm. Products obtained were submitted to flexural testing, compressive strength testing and resistance to acid attack and Scanning Electron microscopy (SEM) observations were made after a period running from 28 to 180 days of drying. The results show an increase in the mechanical properties of products with glass powder and an improvement in the durability of mortar in acidic environment. Such improvements are related to the enhanced adhesion created between crushed glass pieces and cementitious matrix containing glass powder as a result of pozzolanic reaction.

关键词： Pozzolanic Reaction Crushed Glass Glass Powder Alkali-Silica Reaction

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Detection of Burned Areas through Spectral Indices Analysis of Sentinel-2A Satellite Images in the Abokouamékro Wildlife Reserve (Central, Côte D’Ivoire)

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Open Journal of Applied Sciences 2024年第1期14卷 205-222页

作者： Bob Kouakou kouadio Sié Ouattara Alain clément Jean-Marc Gala Bi Zaouri Jean-Luc kouadio Kouassi Jean-Luc Edouard Kouakou N’guessan Laboratoire des Sciences et Technologies de la Communication et de l’Information (LSTCI) Institut National Polytechnique Houphou&#235t Boigny (INP-HB) Yamoussoukro C&#244te d’Ivoire Laboratoire des Sciences Agronomiques et Génie Rural Institut National Polytechnique Houphou&#235t Boigny (INPHB) Yamoussoukro C&#244te d’Ivoire Ecole de Géomatique et du Territoire (EGT) Abidjan C&#244te d’Ivoire LARIS SFR MATHSTIC Université d’Angers Angers France Centre Universitaire de Recherche et d’application en Télédétection (CURAT) UFR des Sciences de la Terre et des Ressources Minières Abidjan C&#244te d’Ivoire Laboratoire de Botanique UFR Biosciences Université Félix Houphou&#235t Boigny Abidjan C&#244te d’Ivoire

In Côte d’Ivoire, the recurring and unregulated use of bushfires, which cause ecological damage, presents a pressing concern for the custodians of protected areas. This study aims to enhance our comprehension of the dynamics of burnt areas within the Abokouamékro Wildlife Reserve (AWR) by employing the analysis of spectral indices derived from satellite imagery. The research methodology began with the calculation of mean indices and their corresponding spectral sub-indices, including NDVI, SAVI, NDWI, NDMI, BAI, NBR, TCW, TCG, and TCB, utilizing data from the Sentinel-2A satellite image dated January 17, 2022. Subsequently, a fuzzy classification model was applied to these various indices and sub-indices, guided by the degree of membership α, with the goal of effectively distinguishing between burned and unburned areas. Following the classification, the accuracies of the classified indices and sub-indices were validated using the coordinates of 100 data points collected within the AWR through GPS technology. The results revealed that the overall accuracy of all indices and sub-indices declines as the degree of membership α decreases from 1 to 0. Among the mean spectral indices, NDVI-mean, SAVI-mean, NDMI-mean exhibited the highest overall accuracies, achieving 97%, 95%, and 90%, respectively. These results closely mirrored those obtained by sub-indices using band 8 (NDVI-B8, SAVI-B8, and NDMI-B8), which yield respective overall accuracies of 93%, 92%, and 89%. At a degree of membership α = 1, the estimated burned areas for the most effective indices encompassed 2144.38 hectares for NDVI-mean, 1932.14 hectares for mean SAVI-mean, and 4947.13 hectares for mean NDMI-mean. A prospective approach involving the amalgamation of these three indices could have the potential to yield improved outcomes. This study could be a substantial contribution to the discrimination of bushfires in Côte d’Ivoire.

关键词： Spectral Indices Wildfire Burned Areas Abokouamékro Wildlife Reserve Côte D’Ivoire

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Production of Yam Tubers Using Seed Tubers from Vitroplants Regenerated from Aerial Stems in the Yam Species Dioscorea alata (L.) and Dioscorea cayenensis-rotundata (L. & P.) in Côte d’Ivoire

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Advances in Bioscience and Biotechnology 2024年第3期15卷 184-194页

作者： koffi Honoré Kouamé Kouakou Marius Konan kouadio Ignace Kouassi Kouablan Edmond koffi Assanvo Simon-Pierre N’Guetta Department of des Science and Technology University Alassane Ouattara of Bouaké Bouaké C&#244te d’Ivoire Plant Production Research Unit Department of Natural Sciences University Nangui Abrogoua Abidjan C&#244te d’Ivoire Central Biotechnology Laboratory National Center for Agronomic Research (NCAR) Abidjan C&#244te d’Ivoire Genetics Laboratory of Bioscience Research Unit University Félix Houphou&#235t Boigny (UFHB) Abidjan C&#244te d’Ivoire

The aim of this study is to produce large quantities of yam tubers in the field from seed tubers derived from vitroplants regenerated from aerial stem cuttings and farmers’ tuber seeds. Seed tubers from ten yam cultivars, including five from Dioscorea alata (cDa083, cDa053, cDa115, cDa150 and cDa266) and five from Dioscorea cayenensis-rotundata (cDr015, cDr027, cDr150, cDr206 and cDr148) with distinct agro-morphological characteristics, were used as material. A completely randomized block design with 3 replications was used. In each block, all cultivars and seed types were represented. When put into cultivation, the tubers produced by the vitroplants all germinated and gave 100% healthy plants, compared with 86% to 100% healthy plants for the seed tubers produced by the farmers. Yields per hectare ranged from 10 to 25 tonnes for seed tubers produced by in vitro plants, and from 4 to 9 tons for seed tubers produced by farmers. Seed tubers from vitroplants can therefore be recommended to farmers as a solution to the problem of seed tuber unavailability.

关键词： Yams Vitroplants Seed Tubers Yields

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A Comparison of Hydrothermal Aging, SO₂ and Propene Poisoning Effects on NH₃-SCR over Cu-ZSM-5 and Cu-SAPO-34 Catalysts

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Journal of Materials Science and Chemical Engineering 2024年第5期12卷 10-28页

作者： kouadio Brou Albert koffi Konan Martin Zran Van Eric-Simon Horo Kone Unité de Formation et de Recherche des Sciences et de Technologies (UFR ST) Universit&#233 Alassane Ouattara Bouak&#233 C&#244te d&#8217Ivoire Unité de Formation et de Recherche Environnement (UFR E) Universit&#233 Jean Lorougnon Gu&#233d&#233 Daloa C&#244te d&#8217Ivoire Unité de Formation et de Recherche des Sciences des Structures de la Mati&#232re et de Technologie (UFR SSMT) Abidjan C&#244te d&#8217Ivoire

This study was aimed to investigate the effects of hydrothermal aging, propene and SO2 poisoning on the ammonia-selective catalytic reduction (NH3-SCR) performance of both Cu-SAPO-34 and Cu-ZSM-5. The catalytic activities of fresh, aged and poisoned samples were tested in ammonia-selective catalytic reduction (NH3-SCR) of NOx conditions. The XRD, TG and N2-desorption results showed that the structures of the Cu-SAPO-34 and Cu-ZSM-5 remained intact after 750˚C hydrothermally aged, SO2 and propene poisoned. After hydrothermal aging at 750˚C for 12 h, the NO reduction performance of Cu-ZSM-5 was significantly reduced at lower temperatures, while that of Cu-SAPO-34 was less affected. Moreover, Cu-SAPO-34 catalyst showed high NO conversion with SO2 or propene compared to Cu-ZSM-5. However, Cu-ZSM-5 showed a larger drop in catalytic activity with SO2 or propene compared to Cu-SAPO-34 catalyst. The H2-TPR results showed that Cu2 ions could be reduced to Cu and Cu0 for Cu-ZSM-5, while no significant transformation of copper species was observed for Cu-SAPO-34. Meanwhile, the UV-vis DRS results showed that CuO species were formed in Cu-ZSM-5, while little changes were observed for the Cu-SAPO-34. Cu-SAPO-34 showed high sulfur and hydrocarbon poison resistance compared to Cu-ZSM-5. In summary, Cu-SAPO-34 with small-pore zeolite showed higher hydrothermal stability and better hydrocarbon and sulfur poison resistant than Cu-ZSM-5 with medium-pore.

关键词： Hydrothermal Aging Propene and SO2Poisoning Ammonia-Selective Catalytic Reduction(NH3-SCR) Cu-SAPO-34 Cu-ZSM-5

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Application of Sigma Metric Analysis to Evaluate the Performance of the Biochemistry Analytical System in a Medical Biology Laboratory in Côte d’Ivoire

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Journal of Analytical Sciences, Methods and Instrumentation 2024年第1期14卷 14-21页

作者： koffi Akissi Joelle Kouakou Francisk kouadio Charlotte Yeo Karna Ahiboh Hugues Hauhouot-Attoungbré Marie-Laure Biochemistry and clinical Chemistry Unit CeDReS University Hospital of Treichville Abidjan Ivory Coast Department of Biochemistry Clinical Chemistry and Molecular Biology Faculty of Pharmaceutical and Biological Sciences University Felix Houphouet-Boigny Abidjan Ivory Coast

Introduction: The Six Sigma methodology is an opportunity for a better understanding of the performance of analytical methods and for a better adaptation of the quality control management policy of the medical biology laboratory. Using the sigma metric, this study assessed the performance of the Biochemistry analytical system of a medical biology laboratory in Côte d'Ivoire. Methods: Six Sigma methodology was applied to 3 analytes (alanine aminotransferase, glucose and creatinine). Performance indicators such as measurement imprecision and bias were determined based on the results of internal and external quality controls. The sigma number was calculated using the total allowable error values proposed by Ricos et al. Results: For both control levels, ALT had a sigma number greater than 6 (7.6 for normal control and 7.9 for pathological control). However, low sigma numbers, less than or equal to 2 for creatinine (1.4 for normal control and 2 for pathological control) and less than 1 for glucose were found. Conclusion: This study revealed good analytical performance of ALT from the point of view of 6 sigma analysis. However, modifications to the overall quality control procedure for glucose and creatinine are needed to improve their analytical performance. The study should be extended to the entire laboratory’s analytes in order to modify the strategies of quality control procedures based on metric analysis for an overall improvement in analytical performance.

关键词： Six Sigma Qualities Controls Bias Imprecision Total Allowable Error

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Multicriteria Analysis by Codification for the Determination of Soil Landscape Units in Forest and Pre-Forest Zones of Cote D’Ivoire: The Case of the Square Degrees of M’Bahiakro and Daloa

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International Journal of Geosciences 2024年第1期15卷 12-24页

作者： Guy Fernand Yao Derving Baka koffi Emmauel Kassin Bala Mamadou Ouattara Nestor Kouman Yao Kouakou kouadio Amani Jean Lopez Essehi Brou Kouame Albert Yao-Kouame National Agricultural Research Center (CNRA) Central Laboratory Soils Water and Plants (LCSEP) Sustainable Soil Management and Water Control Program Bouaké Ivory Coast Earth Sciences and Mining Resources Training and Research Unit (UFR STRM) Soil Water and Geomaterials Sciences Laboratory (LS2EG) Félix Houphou&#235t-Boigny University Cocody-Abidjan Abidjan C&#244te d’Ivoire Mondelez International Abidjan C&#244te d’Ivoire Training and Research Unit (UFR) Communication Environment and Society Department of Geography University Alassane Ouattara Bouaké C&#244te d’Ivoire Soil Water and Geomaterials Sciences Laboratory (LS2EG) Earth Sciences and Mining Resources Training and Research Unit (UFR STRM) Félix Houphou&#235t-Boigny University Abidjan Ivory Coast

The present study, carried out in the forest (Daloa) and pre-forest (M’Bahiakro) zones of Cote d’Ivoire, aims to determine soil landscape units using the coding method. Geological maps and satellite images (SRTM and Landsat) were used for this purpose. The methodological approach adopted consisted in producing maps of slope, geology, land use and topography using the codification method. These various maps, integrated into a GIS using the coding aggregation method, were used to generate soil landscape maps. Twenty-seven (27) soil landscapes have been identified for the pre-forest zone (M’Bahiakro), with a strong dominance of acid rock over a moderate relief under savannah, forest/degraded forest and crops/fallow. However, the forest zone (Daloa), with forty-one (41) soil landscapes identified over the entire zone, is characterized by a majority of mafic rocks on a medium altitude under forest/degraded forest, water and crops/fallow. The criteria used from the codification method (sum of aggregations) made it possible to predict the spatial distribution of soil map units according to agro-ecological environments in the humid intertropical zone. This is essential for the orientation and reinforcement of soil survey tools. However, a comparative evaluation of the different multicriteria analysis methods for coding and weighting soil landscape unit mapping would enable us to identify the most suitable and efficient method for drawing up base maps for soil surveys.

关键词： GIS Multicriteria Analysis by Coding Soil Landscapes Daloa M’Bahiakro Cote D’Ivoire

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