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Mechanical, Microstructural and Mineralogical Analyses of Porous Clay Pots Elaborated with Rice Husks

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Journal of Minerals and Materials Characterization and Engineering 2018年第3期6卷 257-270页

作者： Yeri Dah-Traoré lamine zerbo Mohamed Seynou Raguilnaba Ouedraogo Laboratory of Molecular and Materials Chemistry Chemistry Department University Ouaga 1 Professor Joseph KI-ZERBO Ouagadougou Burkina Faso

This paper deals with the elaboration of porous ceramic pots with raw clay materials and rice husks for water filtration. The basic raw clays have been mixed with rice husks at different ratio 10% and 15% weight (wt) and sintering at 1200°C, 1300°C and 1400°C for 30 minutes. The elaborated pots have been tested for their densification properties and filtration flow. The mineralogy and microstructure of pot have been also studied to explain the different results. The pot with 10% wt rice husks and sintering at 1300°C during 30 minutes presents a sufficient porosity and mechanical strength to be used for water filtration.

关键词： Ceramic Porous Materials Raw Clay Rice Husks

Study of the Mechanical Behaviour of Mortars Modified with Rice Husk Ash

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Journal of Minerals and Materials Characterization and Engineering 2019年第6期7卷 373-384页

作者： Issiaka Sanou Moustapha Sawadogo Mohamed Seynou lamine zerbo Raguilnaba Ouedraogo Laboratoire de Chimie Moléculaire et de Matériaux équipe de physico-chimie et de Technologie des matériaux UFR/Sciences Exactes et Appliquées Université Joseph KI-ZERBO Ouagadougou Burkina Faso Laboratoire de Chimie et Energies Renouvelables Unité de recherche en Physico-Chimie et Technologie des Matériaux UFR/Sciences et Techniques Université Nazi BONI Bobo-Dioulasso Burkina Faso

The purpose of this work is to study the influence of Rice Husk Ash (RHA) on the mechanical strength of mortars. For this purpose, ash was produced by calcining rice husk at 680°C for 5 hours to produce reactive pozzolan. The chemical and mineralogical composition studied by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and X-Ray Diffraction (XRD) showed that this ash is rich in amorphous silica. The ash presents a good pozzolanic activity with a lime fixation rate of 100% after only 7 days of treatment. The addition of RHA to cement contributes to the formation of calcium silicate hydrate (CSH) and calcium aluminate hydrate of C3ASH6 type. The presence of RHA in the mortars improves their mechanical strength. This improvement is due to the filler effect of RHA and to formation of the CSH resulting from the pozzolanic reactivity between the amorphous silica of the RHA and the portlandite released by hydration of the cement.

关键词： Mortar Rice Husk Ash Mechanical Strength Filler Effect CSH

Production and Characterization of Pozzolan with Raw Clay from Burkina Faso

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Journal of Minerals and Materials Characterization and Engineering 2016年第3期4卷 195-209页

作者： Mohamed Seynou Younoussa Millogo lamine zerbo Issiaka Sanou François Ganon Raguilnaba Ouedraogo Kalsibiri Kaboré Laboratoire de Chimie Moléculaire et des Matériaux UFR/Sciences Exactes et Appliquées Université Ouaga I Ouagadougou Burkina Faso Université Polytechnique de Bobo-Dioulasso UFR/Sciences et Techniques Bobo-Dioulasso Burkina Faso Laboratoire National de Batiment et de Travaux Publics Ouagadougou Burkina Faso

Four raw deposits clayey materials in Burkina Faso have been characterized using X-ray diffraction, infrared spectroscopy and ICP-AES to evaluate their suitability to be used as pozzolan in cement. The samples have been activated by thermal treatment at 730°C during 5 hours. The obtained metakaolin was investigated by means of complementary techniques for their use as pozzolan in building materials. Fineness, surface area and amorphousness of metakaolins were the dominant factors which influenced their pozzolan reactivity. The compressive strengths of blended specimens were slightly increased with metakaolins named MK1 and MK2 than the reference for the substitution of 20 - 25 wt%. This was due to the metakaolins’ pozzolan reactivity and their filler effects which promoted CSH formation and reduced pores in the specimens. MK1 and MK2 were suitable for replacement of Portland cement in the field of building materials.

关键词： Raw Clayey Materials Characterization Metakaolin Pozzolan Reactivity Building Materials

Usability of a Natural Tuff as Admixture in Clinker and Its Influence on the Physico-Chemical and Mechanical Properties of Mortar

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Journal of Minerals and Materials Characterization and Engineering 2021年第5期9卷 480-498页

作者： lamine zerbo Moustapha Sawadogo Youssouf Sawadogo Salfo Salogo Moussa Ouedrago Mohamed Seynou Gisèle Lecomte-Nana Philippe Blanchart Laboratoire de Chimie Moléculaire et des Matériaux (LC2M) University Joseph Ki-Zerbo Ouagadougou Burkina Faso Centre Européen de la Céramique Limoges France

The mechanical and physical properties of TUFF from Korsimoro (Burkina Faso) were investigated for use as admixtures in clinker to make pozzolanic cement. Six different cement mortar specimens were prepared by replacing clinker with TUFF in ratios of 0%, 5%, 8%, 10%, 13% and 15% by mass. The flexural and compressive strengths of the specimens were determined at the ages of 2, 7, 28 and 60 days. The effects of the TUFF replacement ratio on workability, setting time and volume expansion were also examined. Based on the results, it was concluded that Korsimoro TUFF has pozzolanic activity and is suitable for use as an alternative adherent material in the cement industry.

关键词： Pozzolan Tuff Admixture Cement Mortar

Characterization of Peanut Shells for Their Valorization in Earth Brick

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Journal of Minerals and Materials Characterization and Engineering 2020年第4期8卷 301-315页

作者： Ouanmini Bobet Sory Nassio Mohamed Seynou Bakiono Remy lamine zerbo Issiaka Sanou Moustapha Sawadogo Younoussa Millogo Escadeillas Gilles University Joseph KI-zerbo UFR-SEA Ouagadougou Burkina Faso University Nazi BONI UFR-ST Bobo-Dioulasso Burkina Faso Laboratoire Matériaux et Durabilité des Constructions (LMDC) Université de Toulouse UPS INSA Toulouse France

Peanut shells from Burkina Faso were characterized using mineralogical, microstructural and chemical methods to perform its possibility to be used as reinforce in adobe bricks. It consists of cellulose (48 wt%), hemicellulose (3 wt%) and lignin (28 wt%). The peanut shells were characterized by high porosity and showed water absorption around 198% at 72 hours. Its chemical composition is essentially composed of silica, iron oxides, alumina and calcium oxide. Its microstructure showed that the peanut shells were a compilation of microfibers with high porous of borders. In watery solution, the peanut shells released polyphenols. Thermal conductivity of peanut at 25 °C was 0.155 ± 0.021 W/mK. The physico-chemical characteristics of peanut shells were similar to those found with agricultural by-products used in adobe reinforce.

关键词： Agricultural Wastes Peanut Shells Thermal Conductivity Adobes Durability

Optimization of Contents of Three Raw Clay Materials in Formulation of a Porcelain

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Journal of Materials Science and Chemical Engineering 2022年第1期10卷 41-58页

作者： Youssouf Sawadogo Moustapha Sawadogo Moussa Ouédraogo Mohamed Seynou Gisèle Lecomte-Nana Philippe Blanchart Moussa Gomina lamine zerbo Laboratory of Molecular Chemistry and Materials (LC2M) University Joseph KI-ZERBO Burkina Faso Institute of Research in Ceramic (IRCER) UMR-CNRS European Ceramic Center Limoges France Laboratory of Cristallography and Material Sciences (CRISMAT) UMR National Graduate School of Engineering of Caen (ENSICAEN) Caen France

Formulation of traditional hard porcelain generally requires 50% kaolin, 25% silica and 25% feldspar. Four porcelains formulation using the casting method, were prepared with different percentages of kaolinitic clay, sand and pegmatite referenced respectively NONG, SAB and PEG. The physico-chemical, mechanical and mineralogical characteristics were evaluated on specimens formulated and sintered at different temperatures from 1200˚C to 1300˚C. X-ray diffraction has revealed the presence of mullite and quartz as essentially crystalline phases. The specimen formulated with 55% NONG, 25% PEG and 20% SAB and sintered at 1240˚C gives better performance (water absorption: 0.17%, density: 2.42, open porosity: 0.42% and flexural strength: 53.54 MPa).

关键词： Raw Minerals Porcelain Characterization Chemical Durability and Phase Transformations

Urban Dynamics and Emergence of New Centers in the Dakar Region (Senegal)

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Journal of Geographic Information System 2024年第4期16卷 227-243页

作者： Mouhamadou Moustapha Mbacké Ndour Mohamed lamine Ndao Alphousseyni Ndonky UFR Engineering Sciences Iba Der Thiam University of This This Senegal Higher School of Applied Economics (ESEA) Cheikh Anta DIOP University Dakar Senegal

Due to the status of the Dakar region as the former capital of AOF (French West Africa) and current capital of the Republic of Senegal, it is home to a very large part of the population and most of the socio-economic, administrative and cultural activities on a very small area of the country (0.28%). This situation makes it a very attractive region and subject to strong land pressure. The objective of this article is to study past and current urban dynamics as well as changes in natural spaces, in order to identify new urban centers. The methodological approach consists in analyzing satellite images to understand the evolution of different forms of spatial occupation in the Dakar region, and to study population movement flows and urban forms in order to reveal new urban centers. The results of the study show that the Dakar urban space is characterized by diverse forms which express a heterogeneous set of spaces. They also revealed the emergence of new clusters between 1986 and 2016, notably Ngor, Grand Yoff, Parcelles Assainies in the North-West, and Keur Massar and the North of the communes of Rufisque in the eastern part of the Dakar region.

关键词： Urban Dynamics Movement Flows Urban Forms Land Use Dakar

Predictive Factors of Renal Damage during Sickle Cell Disease at the Hematology-Oncology Department of Donka University Hospital

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Open Journal of Nephrology 2024年第3期14卷 302-312页

作者： Moussa Traoré Ansoumane Sayon Kanté Marthe Sidibé Mamady Diakité Mohammed lamine Tégui Camara Foussény Diakité Mamadou Saliou Baldé Ibrahima Chérif Mustapha Komrabai-Kanu Mohammed lamine Kaba Nephrology-Hemodialysis Department of Donka University Hospital Conakry Guinea Hematology-Oncology Department of Donka University Hospital Conakry Guinea Hematology-Oncology Department of Ignace Deen University Hospital Conakry Guinea Medical Care Clinic Freetown Sierra-Leone

Introduction: Sickle cell disease, which is the most common hereditary hemoglobinopathy in the world, attacks all body systems, particularly the kidneys. The view of this study was to investigate the predictive factors of kidney damage during sickle cell disease. Materials and methods: It was a retrospective, descriptive and analytical study on files of sickle cell patients hospitalized in the Hematology-Oncology Department of Donka University Hospital during a period from January 1, 2016 to December 31, 2019. Records of sickle cell patients with one or more renal abnormalities were retained. Sickle cell patients without kidney damage were also selected for a comparative study. Only patients without sickle cell disease were excluded. Results: Seventy-five (75) medical records were collected during the study period. From these cases, thirteen (13) records with kidney disease were observed, a frequency of 17%. The mean age of patients was 24.2 years for extremes of 10 and 65 years. The sex ratio was 1.6 in favor of men. The SSFA2 form was the most represented with 92%. 24-hour proteinuria was measured in 13 patients between whom 6 patients (46.2%) had a proteinuria level ≤ 1 g. Eight (8) patients (61.5%) were in stage 1 of chronic kidney disease. The most common type of renal involvement was tubulo-interstitial nephropathy with 8 patients (61.5%). Bivariate analysis showed that elevated serum creatinine (P 2 form of the sickness (P Conclusion: After the observation of an increased serum creatinine and urea, a predominance observation of the SSFA2 form, it should be possible to target patients for whom screening for kidney damage should henceforth be systematic.

关键词： Kidney Damage Predictive Factors Sickle Cell Disease Donka

Infantile Spinal Muscular Atrophy at the Albert Royer National Children’s Hospital Center in Dakar

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Open Journal of Pediatrics 2024年第3期14卷 514-521页

作者： Guillaye Diagne Khadim Bop Sofiatou Dieye Arame Faye Fatou Ly Amadou lamine Fall Pediatrics Ward of Pikine Hospital Pikine Senegal Pé diatrics Ward of Albert Royer National Hospital Dakar Senegal

Introduction: Infantile spinal muscular atrophy (ISA) is an autosomal recessive disease caused by primary degeneration of cells in the anterior horn of the spinal cord, leading to muscle weakness and hypotonia. Its incidence is estimated at 1 in 6000 births worldwide. In Africa, particularly in Senegal, there are few studies interested on this pathology. We therefore deemed this study necessary, which set itself the objective of describing the diagnostic, therapeutic and progressive aspects of infantile spinal muscular atrophy at the Albert Royer National Children’s Hospital Center in Dakar (CHNEAR). Methodology: We conducted a retrospective descriptive study over a period of two (2) years from December 2020 to December 2022. Included were all hospitalized patients in whom the diagnosis of spinal muscular atrophy was made with or without genetic confirmation. The data were collected on a pre-established form then entered and analyzed with the following software: Excel 2013 and R version 4.1.3. Results: During our study period, 2100 children were hospitalized, the annual incidence was 0.76%. The average age of our patients was 9 ± 9 months with a range of 3 months to 32 months and the median was 6.5 months. The sex ratio was 7. The notion of family consanguinity was found in 62.5% of cases and the notion of ISA in the family in 25% of cases. Hypotonia and respiratory distress were found at the forefront in equal proportions (50% of cases). Electromyogram (EMG) was performed in 3 patients (37.5%). Symptomatic medical treatment was administered in 100% of patients, 04 patients had benefited from respiratory physiotherapy, i.e. 50% of cases, and genetic counseling was carried out in one patient (12.5%). The evolution was immediately favorable in 2 patients or 25% of cases, unfavorable in 75% of cases with a death rate of 50% and the average age of death was 5.5 months ± 1 with extremes ranging from 3 to 7 months. Conclusion: The number of Infantile spinal muscular atrop

关键词： Spinal Muscular Atrophy Child Hypotonia Dakar