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Characterization of Sediment from Ourokessoum, North Cameroon: Morphostructural, Mineralogical, and Physicochemical Properties

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Journal of Geoscience and Environment Protection 2024年第9期12卷 51-76页

作者： Atangana Jacqueline Ntsama Kadaguina Doussana Joseph Roland Atenga Essama Akoa Philémon Rémi Etoundi bilobi Roland Touna Jean pierre Nguetnkam Department of Earth Sciences Faculty of Science University of Yaound I Yaound Cameroon Department of Earth Sciences Faculty of Science University of Ngaoundere Ngaoundr Cameroon College of Civil Engineering and Architecture China Three Gorges University Yichang China Department of Mining Geology School of Geology and Mining Engineering University of Ngaoundere Meiganga Cameroon

The present study examines the morphological, physicochemical, and mineralogical specificity of clay sediments in the Hamakoussou basin with the objective of exploring their potential applications. Field data collection was followed by a series of physicochemical and mineralogical tests on the clay samples. Results show that the clay layers, which range in thickness from 11 - 120 cm, exhibit gray, yellowish, or greenish colors. From a physicochemical perspective, these clay layers are found to be basic with a pH ranging from 8.5 for the higher Hama2 layer to 7.6 for the lower Hama1 layer. The sum of exchangeable bases (S) is medium to high with higher values in the Hama1 layer (53.45 meq/100g) and lower values in the Hama3 layer (17.09 meq/100g). Similarly, the cation exchange capacity (CEC) varies from 62.32 meq/100g for the higher Hama1N4 clay layer to 35.6 meq/100g for the lower Hama1N3 clay layer. Mineralogically, the clay materials are primarily composed of smectites, with illite, kaolinite, calcite, quartz, feldspar, hematite, and goethite also present. This study emphasizes the versatility of clay in various industries and scientific domains. It is known for its impermeability, plasticity, and fossil-preserving capabilities, making it a valuable material for economic, practical, and academic applications.

关键词： Morphostructural Sediments Clay Layers Sedimentary basin Hamakoussou

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Typology and Agroecology of Agroecosystems in Vegetation Dynamics in the Ecotones of the Mbam and Inoubou

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Open Journal of Forestry 2024年第1期14卷 42-66页

作者： Alex bruno Dong Etchike Lucie Félicité Temgoua bertine Tiokeng Marie Caroline Momo Solefack Martin benoit Ngassoum pierre Marie Mapongmetsem Laboratory of Applied botany Faculty of Sciences of the University of Dschang Dschang Cameroon Department of Forestry Faculty of Agronomy and Agricultural Sciences University of Dschang Dschang Cameroon National School of Agro-Industrial Sciences of the University of Ngaoundéré Ngaoundéré Cameroon Laboratory of biodiversity and Sustainable Development of the University of Ngaoundéré Ngaoundéré Cameroon

Agroforestry systems strongly characterize the Cameroonian agrarian landscape. Agroforests are among those structuring the ecotones of Mbam and Inoubou in the Central Cameroon region. Numerous works on agroecosystems of Central and South Cameroon, few have come out contribution of the structure of these traditional systems in the dynamics of the vegetation of these forest-savannah ecotones. The present contribution has the overall objective of demonstrating the structural efficiency of agroforests the dynamics of ecotone vegetation, but also in the conservation of biodiversity. To do this, a participatory analysis was carried out with 56 farmers distributed in the five villages of Makénéné. botanical inventories supplemented socio-economic household surveys. The data collected was subjected to various analyzes (univariate test, analysis of variance, multivariate test, PCA, CAH). The results reveal that 55.2% of agroforests are less than 15 years old and those with an area greater than 1500 m2 predominate (33%). They are mainly young with generally small surface areas. The horizontal structure reveals that the largest diameter classes are those of [20 - 30 cm[ and [10 - 20 cm[ with a very low rate of basal area. Agroforests with trees over 10 m high are dominant in five villages of Makénéné. Two types of structural profiles characterize the agroforestry flora of the area, namely intensive pluristratified home gardens on savannah and intensive pluristratified agroforests under forest-savannah transition vegetation. Principal Component Analysis (PCA) and Ascending Hierarchical Clustering (HAC) show three Agroforest Clusters each. The PCA distribution reveals that woody biomass (Y) is strongly correlated with tree diameter (DbH) and significantly with height (Cluster 2). The age (AAG) (Cluster 1) of these agroforests, on the other hand, remains independent of the density (DST) of these trees (Cluster 3). The agroforests in the Nyokon, Carrière and Mocksud vil

关键词： Agroforests Agroecosystem Center Cameroon Dynamics Agroecology Typology

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Diatom and Diatomite: Different Focus on Natural Media to Material Science Path

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American Journal of Analytical Chemistry 2024年第1期15卷 1-29页

作者： Secou Sall Vasiliki Papaefthimiou Thierry Dintzer Fabrice Vigneron Eric brendlé pierre Petit Tom Ferte Saliha Haddoum Sana Labidi Corinne Petit ICPEES UMR-CNRS 7515 Strasbourg University Strasbourg France Adscientis Wittelsheim France ICS CNRS UPR 22 Strasbourg France IPCMS UMR CNRS 7504 Strasbourg University Strasbourg France Ecole Nationale Polytechnique El-Harrach Algeria

bio-silica issued from diatom, a microalgae, is attracted increasing attention in material science thanks to its peculiar nanoarchitecture and related properties with versatile applications. The present work is a deep analysis on morphological and chemical properties of bio-silica issued from fossil origin (diatomaceous earth) and living one (algal paste). An optimization in purification protocol was performed to obtain multiparous bio-silica from its raw media with keeping its original shape entirely. Multiple characterization methods as scanning electronic microscopy (SEM), infrared spectroscopy, x-ray diffraction (DRX), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), nitrogen adsorption and inverse gas chromatography (IGC), were used to check the purification protocol efficiency as well as to gather accurate information on morphology and chemical composition of diatom material obtained in large amount.

关键词： Diatom Diatomite bio-Silica Purification Frustule

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Mobility of Major and Trace Elements during the bauxitization Processes in Ngaoundal Area (Adamawa Cameroon): Implication on Mining Perspectives

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Open Journal of Geology 2024年第1期14卷 81-100页

作者： André Sini Harouna boukari Ondoa Augustin Désiré balla Djetenbe beral Salomon Wangmené Awé Simon Djakba basga Jean pierre Nguetnkam Department of Mining Engineering School of Geology and Mining Engineering University of Ngaoundere Ngaoundere Cameroon Department of Mining Engineering and Environment School of Mining Industry and Geology University of Abdou-Moumouni Niamey Niger Department of Earth Sciences Faculty of Science University of Ngaoundere Ngaoundere Cameroon Department of Mining Engineering Saint Jerome Polytechnic Saint Jerome Catholic University Institute of Douala Douala Cameroon Institute of Agricultural Research for Development (IRAD) Garoua Cameroon

This study was focused to assess major and trace elements in bauxitic duricrusts from Ngaoundal and its surroundings in order to establish their mining interest. To this end, fieldworks, mineralogical and geochemical analyses were carried out. Four facies of duricrust were identified and characterized from the summit to the top of the slope of the Ngaoundal mountain: scoriaceous, pisolitic, nodular and massive. Mineralogical and geochemical analyses performed on 16 samples, revealed a significant concentration of Alb>2b>Ob>3b> mainly in the scoriaceous facies (over 45% in grade), moderate in Feb>2b>Ob>3b> (averaging 23.69%) and SiOb>2b> (averaging 21.7%). Trace elements were generally low, excluding Cr (421 ppm on average), Zr (327 ppm on average and V (213 ppm on average). In addition, the limited quantities of alkalis (Nab>2b>O, Kb>2b>O) and alkaline earths metals (MgO, CaO) coupled with the very high values of Chemical Index of Alteration (CIA) and Mineralogical Index of Alteration (MIA), (more than 99%) attest to the intense weathering of the studied materials. Allitization and monosiallitization constituted the crystallochemical phenomena that have led to the development of bauxitic minerals. More than 90% of gibbsite in scoriaceous facies, 52.21% - 76.01% of kaolinite in pisolitic facies and more than 40% of hematite in nodular facies were quantified. The relationships between the constitutive components indicated their interdependency during the bauxitization phenomenon. The mineralogical and geochemical properties highlighted the mining interest of the studied duricrusts to be valorized.

关键词： Duricrust bauxitization Phenomenon Mineralogical and Geochemical Characterization Major and Trace Elements Mining Potential

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备用电池的扩展运用

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国外铁道机车与动车 2024年第2期 46-48页

作者： [美]pierre Prenleloup 李梦斐(译) 不详

镍电池最早装载于地铁车辆用作车载备用电源,当车辆需要紧急牵引时,镍电池也可提供动力,相较于安装独立的电池包,其具有很好的成本优势。

关键词： Saft公司 MSX电池莫斯科-2020车队

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在不同文化间架起沟通的桥梁

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紫禁城 2024年第3期350卷 120-125页

作者：皮埃尔·雷诺(pierre Rainero) 杨锐(译) 卡地亚

卡地亚,创立于一八四七年的法国巴黎,是皇室御用珠宝商。同时作为一家有着深厚历史和自身文化的国际品牌,卡地亚一直积极推动与支持全球艺术与文化交流,与法国凡尔赛宫和故宫博物馆两座世界级艺术殿堂都保持着长久而密切的关系,多次参... 详细信息

卡地亚,创立于一八四七年的法国巴黎,是皇室御用珠宝商。同时作为一家有着深厚历史和自身文化的国际品牌,卡地亚一直积极推动与支持全球艺术与文化交流,与法国凡尔赛宫和故宫博物馆两座世界级艺术殿堂都保持着长久而密切的关系,多次参与支持展现中西方文化相互影响的展览。

关键词：国际品牌卡地亚凡尔赛宫艺术殿堂艺术与文化中西方文化珠宝商相互影响

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Associated Factors with Early Sexual Intercourse among In-School Adolescents in brazzaville

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Open Journal of Pediatrics 2024年第5期14卷 898-907页

作者： Aymar pierre Gildas Oko Dumez Ngoma Judicaël Kambourou Eryx Darius Mbou Essie Neli Yvette Ngakengni Lynda Tchidjo Ngamo Georges Marius Moyen Faculty of Health Sciences Marien Ngouabi University of Brazzaville Brazzaville Congo Department of Pediatrics Teaching Hospital Center of Brazzaville Brazzaville Congo

background: Early sexual intercourse (ESI) is a global public health problem. In Congo, associated factors with ESI have been under-studied. Objective: To analyse factors associated with early sexual intercourse among in-school adolescents in brazzaville. Method: A cross-sectional analytic study with three-stage random sampling was carried out from March 2 to June 2, 2022 in brazzaville secondary and high schools. Adolescents in the selected schools were interviewed about their sexual and social behaviour, and their family and school environment. Multivariate analysis using logistic regression was used to identify factors associated with ESI. The significance level of the p-value was set at 5% and the confidence interval at 95%. Results: Of a total of 1100 adolescents surveyed, 800 (72.7%) had ESI, 98% of them were female. The main reason for early initiation of sexual intercourse was curiosity (81.8%). Non-use of condoms and multiple sexual partnerships were noted respectively in 98.7% and 68.7% of adolescents who had experienced ESI. Female gender (p Conclusion: The prevalence of ESI is high, and the factors identified in this study may help to reduce it.

关键词： Associated Factors Early Sex Adolescents brazzaville

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A Review on Complex System Engineering

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Journal of Systems Science & Complexity 2020年第6期33卷 1755-1784页

作者： PARREND pierre COLLET pierre ECAM Strasbourg-Europe 2Rue de MadridSchiltigheimFrance University of Strasbourg StrasbourgFrance

Complexity is commonly summarized as‘the actions of the whole are more than the sum of the actions of the parts’.Understanding how the coherence emerges from these natural and artificial systems provides a radical shift in the process of thought,and brings huge promises for controlling and fostering this *** authors define the term‘Complex System Engineering’to denote this approach,which aims at transferring the radical insights from Complex System Science to the pragmatic world of engineering,especially in the Computing System Engineering domain.A theoretical framework for Complex System Engineering is built by the morphogenetic engineering framework,which identifies a graduation of models,in growing order of generative *** implementation of Complex System Engineering requires a portfolio of operational solutions:The authors therefore provide a classification of Complex System application approaches to answer this challenge and support the emergence of Complex System Engineers capable of addressing the issues of an ever more connected world.

关键词： Complex networks complex software engineering complex systems design structure matrix emergent engineering evolutionary algorithms organically grown architectures

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Resistant Pulmonary Tb-HIV Co-Infection in an Infant: About a Case

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Open Journal of Pediatrics 2024年第2期14卷 420-425页

作者： Mariam Maiga pierre Togo Tati Simaga Mariam Traoré Moussa Konaté Mamadou Diallo Alou Samaké Mamadou Keïta Korotoumou Wélé Diallo Djibril Kassogué Pediatrics Department Distric VI Reference Health Center Bamako Mali Paediatrics Department Gabriel Touré Teaching Hospital Bamako Mali Pediatrics Department Mali Hospital Bamako Mali Paediatrics Department Timbuktu Regional Hospital Bamako Mali

Diagnosis of childhood tuberculosis (Tb) is difficult, especially in resource-limited countries where the number of reported cases of Tb-HIV co-infection continues to rise. This co-infection poses a diagnostic and therapeutic problem for caregivers. We report a case of rifampicin-resistant HIV-Tb pulmonary coinfection in a 19-month-old infant.

关键词： Tuberculosis Rifampicin Resistance HIV Infants

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biodiversity of Edible Caterpillars of Imbrasia and Host Plants in boukoko (Central African Republic)

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Advances in Entomology 2024年第1期12卷 38-55页

作者： Lucie Aba-Toumnou Solange-Patrica Wango Denis beina Jean-pierre Moalbaye Gorgon Igor Touckia Rufin Reo-Ndouba Felix Allah-barem Olga Diane Yongo Laboratory of biological and Agronomical Sciences for Development Faculty of Sciences University of Bangui Bangui Central African Republic Laboratory of Applied Animal biology and biodiversity University of Bangui Bangui Central African Republic Center of Studies and Research on Pharmacopoeia and Traditional African Medicine (CERPHAMETA) University of Bangui Bangui Central African Republic Plant and Fungal biodiversity Laboratory Faculty of Science University of Bangui Bangui Central African Republic Higher Institute for Rural Development (ISDR) University of Bangui Mba&iumlki Central African Republic Central African Republic Institute of Agriculture Research Bangui Central African Republic

In Central African Republic, edible caterpillars of Imbrasia gender are income of rural populations, present an opportunity to improve food security and belonging to the category of Non-wood forest products. The goal of this study is to document the ecology of caterpillars of genre Imbrasia in relation to its host plants in boukoko. The questionnaire was addressed to the actors of the collection and consumption of caterpillars in this Commune, to their local knowledge concerning this food resource as well as the plants of their locality on which caterpillars are collected. The survey took place in September to October 2022 and as a general rule, the 120 respondents were elderly people whose age range varied from 35 to 70 years old. Plant samples are collected in their natural environment. based on local names;herbaria are mounted, plants photographed and samples collected. The types of edible caterpillars have been inventoried in the field in collaboration with the local populations who consume them. based on local names, the caterpillars are captured manually from morphological traits and then stored in bottles containing 70% ethanol. The specimens were identified. The data was entered into the Excel spreadsheet which also made it possible to produce histograms with the frequencies of the plant species most valued by the different caterpillars. A Principal Component Analysis (PCA) was then performed using R software to highlight the correlation between caterpillars and host plants. The main economic importance trees hosting edible caterpillars of Imbrasia gender in boukoko region are: Entandrophragma cylindricum, Pentaclethra macrophylla, Maesopsis eminii, Albizia ferruginea, Macaranga spinosa, Amphimas ferrugineus, Pentaclethra macrophylla, Racosperma auriculiforme, Eribroma oblonga. The Principal Component Analysis (PCA) carried out to assess the variability between the different species of caterpillars according to their host plants shows that the first two axes

关键词： Forest Degradation Losing biodiversity of Consumed Insects Local Population

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