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Advancing respirable coal mine dust source apportionment:a preliminary laboratory exploration of optical microscopy as a novel monitoring tool

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International Journal of Coal Science & Technology 2024年第2期11卷 222-233页

作者： nestor Santa Emily Sarver Department of Mining and Minerals Engineering Virginia TechBlacksburgVA 24061USA

Exposure to respirable coal mine dust(RCMD)can cause chronic and debilitating lung ***-time monitoring capabilities are sought which can enable a better understanding of dust components and *** many underground mines,RCMD includes three primary components which can be loosely associated with three major dust sources:coal dust from the coal seam itself,silicates from the surrounding rock strata,and carbonates from the inert‘rock dust’products that are applied to mitigate explosion hazards.A monitor which can reliably partition RCMD between these three components could thus allow source *** tracking silicates,specifically,could be valuable since the most serious health risks are typically associated with this component-particularly if abundant in crystalline *** a monitoring concept based on field microscopy,and following up on prior research using polarized light,the aim of the current study was to build and test a model to classify respirable-sized particles as either coal,silicates,or *** model development,composite dust samples were generated in the laboratory by successively depositing dust from high-purity materials onto a sticky transparent substrate,and imaging after each deposition event such that the identity of each particle was known a *** testing followed a similar approach,except that real geologic materials were used as the source for each dust *** showed that the model had an overall accuracy of 86.5%,indicating that a field-microscopy based moni-tor could support RCMD source apportionment and silicates tracking in some coal mines.

关键词： Polarized light microscopy Image processing Dust monitoring Respirable silica Coal mining

Dynamics analysis and cryptographic implementation of a fractional-order memristive cellular neural network model

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Chinese Physics B 2024年第4期33卷 418-433页

作者：周新卫蒋东华 Jean De Dieu Nkapkop Musheer Ahmad Jules Tagne Fossi nestor Tsafack 吴建华 Department of Information Engineering Gongqing CollegeNanchang UniversityJiujiang 332020China School of Computer Science and Engineering Sun Yat-Sen UniversityGuangzhou 511400China Department of Electrical Engineering and Industrial Computing University Institute of TechnologyDoualaCameroon Department of Computer Engineering Jamia Millia IslamiaNew Delhi 110025India Department of Physics Faculty of ScienceUniversity of YaoundeCameroon Electrical Engineering Department and Industrial Computing of ISTAMA University of DoualaDoualaCameroon

Due to the fact that a memristor with memory properties is an ideal electronic component for implementation of the artificial neural synaptic function,a brand-new tristable locally active memristor model is first proposed in this ***,a novel four-dimensional fractional-order memristive cellular neural network(FO-MCNN)model with hidden attractors is constructed to enhance the engineering feasibility of the original CNN model and its ***,its hardware circuit implementation and complicated dynamic properties are investigated on multi-simulation ***,it is used toward secure communication application *** it as the pseudo-random number generator(PRNG),a new privacy image security scheme is designed based on the adaptive sampling rate compressive sensing(ASR-CS)***,the simulation analysis and comparative experiments manifest that the proposed data encryption scheme possesses strong immunity against various security attack models and satisfactory compression performance.

关键词： cellular neural network memristor hardware circuit compressive sensing privacy data protection

Male and Female Hypogonadisms: Etiological, Metabolic and Osteodensitometric Aspects

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Open Journal of Endocrine and Metabolic Diseases 2024年第2期14卷 39-52页

作者： nestor Ghislain Andzouana Mbamognoua Ikram Damoune Sana Doubi Asmae Lahlou Farida Ajdi Department of Metabolic and Endocrine Diseases Brazzaville University Hospital Brazzaville Republic of the Congo Faculty of Health Sciences Marien Ngouabi University Brazzaville Republic of Congo Department of Endocrinology Metabolic Diseases Hassan II University Hospital of Fez Fez Morocco

Introduction: Studies showed a high prevalence of metabolic abnormalities including dyslipidemia, type 2 diabetes in cases of low testosterone in men and which are associated with increased cardiovascular risk. Hypogonadism represents the second cause of endocrine osteoporosis. Objectives: The objectives of our work were: to determine the main causes of hypogonadism in women and men;to assess the frequency of metabolic and osteosdensitometric abnormalities in the hypogonadal population. Patients and methods: A retrospective descriptive study was carried out over 7 years on 120 patients, hospitalized in the Endocrinology department of the Hassan II University Hospital of Fez-Morocco for hypogonadism. The patients selected were those who had symptoms of hypogonadism confirmed in men by: low total testosterone for Tanner stage in adolescents, ng/ml or lower limit of normal for adults;in women, hypoestrogenia 30 pg/l. Gonadotropin dosage, karyotype, pelvic or testicular ultrasound and pituitary MRI, for etiological diagnosis, were performed. Bone densitometry was performed for bone impact and lipid profile for metabolic profile. Results: Out of 120 patients, there were 77 women and 43 men. The average age was 31.51 years. In men, the main causes were central hypogonadism in 67.4% and primary testicular failure in 32.6%. In women, central hypogonadism was also the most common cause noted in 63.7% and premature ovarian failure was observed in 36.4%. HypoHDL was significantly more frequent p (0.005) in women, osteopenia and osteoporosis were significantly more frequent in women than in men p (0.046). Conclusion: Central causes represent the most common etiology of hypogonadism in both sexes;abnormalities of bone mineralization and metabolic disorders were predominant in women.

关键词： Hypogonadism Etiological Metabolic Osteodensitometric Fez

Assessment of Cement-Lime as Stabilizer on Mud Bricks

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Journal of Materials Science and Chemical Engineering 2024年第7期12卷 1-13页

作者： Chrisdel Chancelice Ndjeumi Djonga Paul nestor Djomou George Elambo Nkeng Fatoumata Adda Souaibou Soulemane Anong Department of Environmental Sciences ENSPM University of Maroua Maroua Cameroon Department of Leather and Textile Engineering ENSPM University of Maroua Maroua Cameroon Department of Civil Environmental and Architectural Engineering University of Padova Padova Italy Laboratory of Analysis of CIMENCAM Garoua Cameroon

The aim of this study was to evaluate the compressive strength of clay bricks and their stability to water absorption by inserting stabilizers such as lime and cement of 0%, 4%, 6%, 8%, 10%, 12% to 14%. Spectrometric analysis was used to characterize the various stabilizers and the clay used, and tests of resistance and water absorption were also carried out. The clay was found to be an aluminosilicate (15.55% to 17.17% Al2O3 and 42.12% to 44.15% SiO2). The lime contains 90.84% CaO and the cement has 17.80% SiO2, 3.46% Al2O3, 2.43% Fe2O3 and 58.47% CaO in the combined form of tricalcium silicate, dicalcium silicate, tricalcium aluminate and ferro-tetra calcium aluminate. The results showed that the insertion of locally available stabilizers (lime and cement) improved the strength of the material by almost 80% when the lime was increased from 0% to 14% for 14 days. For compressed cement, a 65% increase in strength was observed under the same conditions. Strength increases with drying time, with a 52% increase in strength at 28 days compared to 14 days. Furthermore, compressed cement bricks have a more compact structure, absorbing very little water (32%). In view of all these results, cement appears to be the best stabilizer, and compression improves compressive strength and reduces water absorption.

关键词： Cement-Stabilized Earth Lime-Stabilized Earth Compressed Earth Brick Compressive Strength Water Absorption Test

Optimization of the Pretreatment of the Mixture of Cassava Peelings and Pineapple Fibers Using Response Surface Methodology and a Process Simulator for the Bioethanol Production

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Energy and Power Engineering 2024年第2期16卷 79-96页

作者： Paul nestor Djomou Djonga George Elambo Nkeng Madjoyogo Hervé Sirma Ahmat Tom Thierry Tchamba Tchuidjang Department of Textile and Leather Engineering National Advanced School of Engineering of Maroua Maroua Cameroon Department of Civil Environmental and Architectural Engineering University of Padova Padova Italy Institut du Génie des Systèmes Industriels et textiles Ecole Polytechnique de Ouagadougou Ouagadougou Burkina-Faso Department of Energy Engineering University Institute of Technology University of Ngaoundere Ngaoundere Cameroon Department of Process Engineering National Advanced School of Agro-Industrial Sciences University of Ngaoundere Ngaoundere Cameroon

The increase in oil prices and greenhouse gas emissions has led to the search for substitutes for fossil fuels. In Cameroon, the abundance of lignocellulosic resources is inherent to agricultural activity. Production of bioethanol remains a challenge given the crystallinity of cellulose and the presence of the complex. The pretreatment aimed to solubilize the lignin fraction and to make cellulose more accessible to the hydrolytic enzymes, was done using the organosolv process. A mathematical modeling was performed to point out the effect of the temperature on the kinetics of the release of the reducing sugars during the pretreatment. Two mathematical model was used, SAEMAN’s model and Response surface methodology. The first show that the kinetic parameters of the hydrolysis of the cellulose and reducing sugar are: 0.05089 min-1, 5358.1461 J·mol-1, 1383.03691 min-1, 51577.6100 J·mol-1 respectively. The second model was used. Temperature is the factor having the most positive influence whereas, ethanol concentration is not an essential factor. To release the maximum, an organosolv pre-treatment of this sub-strate should be carried out at 209.08°C for 47.60 min with an ethanol-water ratio of 24.02%. Organosolv pre-treatment is an effective process for delignification of the lignocellulosic structure.

关键词： Bioethanol Cassava Peeling Pineapple Fibers Organosolv Process and Optimization

Diversity of Macro Invertebrates of the River Rwizi in Western Uganda: A Citizen Science-BioBlitz Approach

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Open Journal of Ecology 2024年第4期14卷 343-365页

作者： John Bosco Nkurunungi Godwin Muhairwe Upton Nuwagira Nickson Araka nestor Mugabe Osbert Natwijuka Jeninah Atwebembeire Mbarara University of Science and Technology Mbarara Uganda Department of Directorate of Research and Graduate Training Makerere University Kampala Uganda

This study elucidates the pivotal role of citizen science-BioBlitz methodologies for rapid assessment of the macro-invertebrate taxa within the threatened River Rwizi of South-western Uganda. Utilizing a comprehensive mixed-methods approach, the investigation focused on six distinct river segments to demonstrate the efficacy of participatory citizen science-BioBlitz approaches conducted by experts, students and community volunteers. BioBlitz events included rigorous macro-invertebrate sampling at each of the selected sites along River Rwizi on nine occasions, incorporating collaborative taxonomic identification procedures involving experts, students, and the local community. Analyzing pollution concerns, diversity metrics, and community narratives yielded insights into river health and socio-ecological dynamics. A total of 43 macro-invertebrate families across 17 orders were documented with class Insecta dominating. Participants in BioBlitz events expressed predominantly positive sentiments, emphasizing satisfaction, education, and heightened awareness, besides negative sentiments rooted in historical mistrust. Intriguingly, the study unveiled an unforeseen trend in macro-invertebrate taxa richness, rising from upstream to urban sprawl and diminishing at peri-urban downstream sites. The study underscores the potential of citizen science-BioBlitz methodologies in advancing community science education and unraveling the intricate dynamics of threatened river ecosystems. The insights offered are invaluable for policymakers and conservationists seeking effective strategies to address challenges in the River Rwizi and comparable ecosystems. .

关键词： Diversity Macroinvertebrates Rwizi Citizen-Science-BioBlitz 6

Composite Panels from the Combination of Rice Husk and Wood Chips with a Natural Resin Based on Tannins Reinforced with Sugar Cane Molasses Intended for Building Insulation: Physico-Mechanical and Thermal Properties

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Journal of Materials Science and Chemical Engineering 2024年第2期12卷 19-30页

作者： Paul nestor Djomou Djonga Rosellyne Serewane Deramne Gustave Assoualaye Ahmat Tom Tégawendé Justin Zaida Department of Textile and Leather Engineering National Advanced School of Engineering of Maroua University of Maroua Maroua Cameroon Department of Chemistry Faculty of Science University of Bangui Bangui Central African Republic Department of Renewable Energy National Advanced School of Engineering of Maroua University of Maroua Maroua Cameroon Department of Energy Engineering University Institute of Technology University of Ngaoundere Ngaoundere Cameroon Institute of Industrial and Textile Systems Engineering Ecole Polytechnique de Ouagadougou Ouagadougou Burkina Faso

The objective of this work is to develop new biosourced insulating composites from rice husks and wood chips that can be used in the building sector. It appears from the properties of the precursors that rice chips and husks are materials which can have good thermal conductivity and therefore the combination of these precursors could make it possible to obtain panels with good insulating properties. With regard to environmental and climatic constraints, the composite panels formulated at various rates were tested and the physico-mechanical and thermal properties showed that it was essential to add a crosslinker in order to increase certain solicitation. an incorporation rate of 12% to 30% made it possible to obtain panels with low thermal conductivity, a low surface water absorption capacity and which gives the composite good thermal insulation and will find many applications in the construction and real estate sector. Finally, new solutions to improve the fire reaction of the insulation panels are tested which allows to identify suitable solutions for the developed composites. In view of the flame tests, the panels obtained are good and can effectively combat fire safety in public buildings.

关键词： Composite Panels Tannins Reinforced Sugar Cane Molasses Building Insulation Mechanical and Thermal Properties

Determinants of the Low Proportion of Pregnant Women Seen for First-Trimester Prenatal Care at KoudougouUrban Medical Center, Burkina-Faso

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Open Journal of Nursing 2024年第8期14卷 421-432页

作者： Swanfani Talardia André Thiombiano nestor Bationo Ziemlé Clément Meda Iliassa Sawadogo Léa Yameogo Cécile Sanou Dieudonné Soubeiga Institut de Formation et de Recherche Interdisciplinaire en Science de la Sant et de lEducation (IFRISSE) Ouagadougou et Ecole Nationale de Sant Publique (ENSP) Bobo-Dioulasso Burkina Faso Department of Public Health Universit Joseph Ki-ZERBO Ouagadougou Burkina-Faso Institut supRieur des Sciences de la Sant (INSSA) de lUniversit Nazi Boni et Centre Hospitalier Universitaire Souro Sanou (CHUSS) Bobo Dioulasso Burkina Faso Direction Rgionale de la Sant et de lHygine Publique des Hauts Bassins Bobo Dioulasso Burkina Faso Direction Rgionale de la Sant et de lHygine Publique du Centre Ouest Koudougou Burkina Faso Ecole Nationale de Sant Publique Direction Rgionale de Bobo-Dioulasso Bobo-Dioulasso Burkina Faso

Introduction: Antenatal care (ANC) contributes to the reduction of maternal and neonatal morbidity and mortality. The study aimed to investigate the determinants of the low proportion of pregnant women seen for first antenatal care in the first trimester of pregnancy at the urban medical center of Koudougou, Burkina Faso. Materials and Methods: This was a cross-sectional study with data collection from June 08 to August 18, 2021. It involved a sample of 302 participants including 280 pregnant women and 22 maternity providers. Semi-structured individual interviews, non-participant observation, and a literature review were used. Results: Pregnant women age 20 and over, knowledge of the date of their last menstrual period, and knowledge of the antenatal care calendar were associated with coming into contact (1) with Antenatal care in the first trimester of pregnancy. In addition, there was a lack of availability of antenatal care services, inadequate reception of clients, and shortages of health products. Conclusion: There is a need to revisit strategies for communicating with women about ANC, reorganizing ANC services, and improving ANC services.

关键词： Least Risk Maternity Maternal and Neonatal Health Maternal and Neonatal Mortality Maternal and Neonatal Morbidity Reception

Nutritional and Sanitary Quality of Infant Flours Produced in Ouagadougou, Burkina Faso

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Food and Nutrition Sciences 2024年第8期15卷 727-743页

作者： Léa Kilô Adam Bayala-Yaï Philippe Augustin Nikièma Hassane Sangaré Fabrice Bationo Imael Henri nestor Bassolé Jacques Simpore Laboratoire de Biologie Molculaire et de Gntique (LABIOGENE) Universit Joseph KI-ZERBO Ouagadougou Burkina Faso Laboratoire de Biologie Molculaire dEpidmiologie et Surveillance des Agents Transmissibles par les Aliments (LaBESTA) Universit Joseph KI-ZERBO Ouagadougou Burkina Faso Laboratoire de Microbiologie et de Physicochimie du Dpartement de Technologie Alimentaire (DTA) Institut de Recherche en Sciences Appliques et Technologies (IRSAT) Ouagadougou Burkina Faso

The quality of infant flours used during the weaning age is of great importance in that it conditions the nutritional health of infants and young children. This study aimed to assess the nutritional and sanitary quality of infant flours produced in the city of Ouagadougou. This was a cross-sectional study including 11 out of 25 infant flour production units that gave their consent to partake in the study. In total, 25 infant flour samples have been collected from July to September 2021. The physicochemical and microbiological parameters were determined according to standard methods. The ANOVA analysis of variance showed significant differences between the means of the physico-chemical and the means of the microbiological parameters respectively. The results showed that 60% of proteins and 80% of lipid and total carbohydrate contents were below the authorised limits. The energy values were below the authorised limit in 88% of the cases. All instant infant flours had microbiological loads compliant with Burkinabè standards. As for infant flour to be cooked, 63.64% and 81.82% had satisfactory numbers of total coliforms and faecal coliforms respectively. Staphylococcus aureus and Escherichia coli were detected in these samples with 86.36% of infant formulae having results below the recommended limit. These results show that the infant flours produced in Ouagadougou were somehow of acceptable quality. However, there is a need to improve the formulae for macronutrient contents, energy values and sanitary quality to comply with the recommendations.

关键词： Nutritional and Sanitary Quality Infant Flours Ouagadougou Burkina Faso