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Flow Dynamics during the Hydrocarbon Exploitation for Prevention and Management of Water Venues in Oil Field: A Study Case of Crystal Field in Badila/Chad

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International Journal of Geosciences 2024年第5期15卷 433-448页

作者： Issakha Tidjani Djimet Huguette Christiane Emvoutou Nicodème Djiedeu jean-pierre Nguenang Laboratory of Fundamental Physics Department of Physics Faculty of Science University of Douala Douala Cameroon Laboratory of Geosciences Natural Resources and Environment Department of Earth Sciences Faculty of Science University of Douala Cameroon

The southern part of the Lake Chad basin is under the gas and oil petroleum industry due to its hydrocarbon potential for about twenty years. This project stands out as the main challenges of the hydrocarbon production and the management of fluxes particularly the groundwater venues. A comprehensive study is thus conducted to develop a dynamic and analytic model for diagnosing the production performances with a particular view on the management of groundwater venues. The three main concerned reservoirs subdivided on subunits evidence their proper characteristics. The porous media, their densities, the internal flows and the water injection techniques such as water flooding were thus adopted. The oil viscosity variability within the reservoirs creates different levels of mobility between water and oil, highlighting the challenges of water management. The material balance model and the behavior of the well analysis were taken in consideration within the identified aquifer, emphasizing the importance of keeping the pressure through injection. The control of water productions, the management of the reservoir, the well strategical position and the specific completions lead to the model functioning. In addition, the CO log and the Pulsed Neutron indicate their limitations as a result of the water salinity and the porosity of the aquifer. The management of groundwater venues at Badila requires various approaches throughout the lifetime of the Crystal field such as the data acquisition and remediation actions and prevention, under a permanent monitoring of the dynamic fluxes in the reservoirs.

关键词： Groundwater Venues Analytic and Dynamic Model Water Flooding Optimization of Production

Fuzzy Henstock-Kurzweil Triple Integral on a Type 1 Quasi-Fuzzy Parallelepipedal Domain

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Journal of Applied Mathematics and Physics 2024年第3期12卷 897-911页

作者： Kumwimba Seya Didier Kasongo Ntambwe Dany Panga Lutanda Grégoire Mayuke Katshongo jean Paul Lunda Ngoy jean pierre Département de Mathématiques et Informatique Faculté des Sciences Université de Lubumbashi Lubumbashi Democratic Republic of the Congo

In this article, we propose by using the Hausdorff distance Simpson’s rule for the triple integral of a fuzzy-valued function and the error bound of this method, one of the variables of which is fuzzy. In addition, thin δ-fine partitions are introduced. The integration domain is a quasi-fuzzy parallelipiped. A numerical example is presented in order to show the application and the significance of the method.

关键词： Fuzzy-Valued Function Hausdorff Distance Quasi-Fuzzy Parallelipiped Henstock Integral

Advancements in Catalysts for Electrochemical Nitrate Reduction: A Sustainable Approach for Mitigating Nitrate Pollution: A Review

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Modern Research in Catalysis 2024年第1期13卷 1-28页

作者： Gerald D. S. Quoie Jr. jean pierre Bavumiragira Varney Kromah State Key Laboratory of Pollution Control and Resources Reuse College of Environmental Science and Engineering Tongji University Shanghai China Key Laboratory of Yangtze River Water Environment Ministry of Education Tongji University Shanghai China Department of Mining Engineering College of Engineering University of Liberia Monrovia Liberia

Nitrate pollution is of great importance in both the environmental and health contexts, necessitating the development of efficient mitigation strategies. This review provides a comprehensive analysis of the many catalysts employed in the electrochemical reduction of nitrate to ammonia, and presents a viable environmentally friendly approach to address the issue of nitrate pollution. Hence, the electrochemical transformation of nitrate to ammonia serves the dual purpose of addressing nitrate pollution in water bodies, and is a useful agricultural resource. This review examines a range of catalyst materials such as noble and non-noble metals, metal oxides, carbon-based materials, nitrogen-doped carbon species, metal complexes, and semiconductor photocatalysts. It evaluates catalytic efficiency, selectivity, stability, and overall process optimization. The performance of catalysts is influenced by various factors, including reaction conditions, catalyst structure, loading techniques, and electrode interfaces. Comparative analysis was performed to evaluate the catalytic activity, selectivity, Faradaic efficiency, current density, stability, and durability of the catalysts. This assessment offers significant perspectives on the structural, compositional, and electrochemical characteristics that affect the efficacy of these catalysts, thus informing future investigations and advancements in this domain. In addition to mitigating nitrate pollution, the electrochemical reduction of nitrate to ammonia is in line with sustainable agricultural methods, resource conservation, and the utilization of renewable energy resources. This study explores the factors that affect the catalytic efficiency, provides new opportunities to address nitrate pollution, and promotes the development of sustainable environmental solutions.

关键词： Nitrate Pollution Electrochemical Reduction Ammonia Sustainable Farming Catalysts

Ethics of Human Resources Management in the Cameroonian Health System, Medical Nomadism and the Ineffectiveness of the Fight against High Blood Pressure

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Health 2024年第1期16卷 9-21页

作者： jean Ndibi Abanda Anicet Onana Akoa Désiré Tchoffo Ulrich Dama pierre Yassa Yoniene Faculty of Health Sciences University of Lisala (CIREP-UNILIS) Lisala Democratic Republic of the Congo National Order of Medical and Sanitary Professions Yaounde Cameroon School of Health Sciences Catholic University of Central Africa Yaounde Cameroon World Health Organization Maroua Cameroon Faculty of Medicine University Simon Kimbangu Kinshasa Democratic Republic of the Congo

Context/objectives: The fight against Chronic Non-Communicable Diseases (NCDs) is a long-term undertaking, which requires available, motivated and well-managed human resources (HR). The administrative management of skills on both qualitative and quantitative levels is one of the essential functions of a health system. To better implement policies of fight against High Blood Pressure (HBP) and other chronic diseases, it is important to establish strategies to retain health personnel. This loyalty requires favorable working conditions and consideration of the contribution-reward couple. Good working conditions are likely to reduce the phenomenon of medical nomadism;conversely, poor HR management can contribute to their exodus towards exotic “green pastures”, thus leading to an additional crisis in the Cameroonian health system. The fight against HBP is a complex, multifaceted and multifactorial reality that requires appropriate management model for all types of resources mainly HR. The main objective of this research is to show the impact of poor management of human resources in Cameroon health system on medical nomadism and the ineffectiveness of the fight against High Blood Pressure. Method: A cross-sectional descriptive survey among five hundred (500) health facilities in the center region of Cameroon has been conducted. A stratified probabilistic technique has been used, and the number of health facilities to be surveyed has been determined using the “sample size estimation table” of Depelteau. The physical questionnaires have been printed and then distributed to data collectors. After data collection, the latter were grouped during processing in Excel sheets. The Chi-square test was used for data with a qualitative value and that of Kolmogorov-Sminorf for data with a quantitative value to assess the normality and reliability of data. The Crochach’s Alpha reliability test allowed us to have a summary of the means and variances and then to search for intragroup cor

关键词： Ethics Human Resources Management Cameroonian Health System Medical Nomadism Ineffectiveness High Blood Pressure

Detection of Adenovirus in Fresh Fruit, Vegetables, Wastewater and Manure from Irrigated Farms in Ouagadougou, Burkina Faso

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Food and Nutrition Sciences 2024年第7期15卷 644-662页

作者： Kuan Abdoulaye Traore Madou Sanou jean Bienvenue Ouoba Bruno Lalidia Ouoba pierre Roques Nicolas Barro Laboratoire de Biologie Molculaire dEpidmiologie et de Surveillance des Bactries et Virus Transmissibles par les Aliments (LaBESTA) Universit Joseph KI-ZERBO Ouagadougou Burkina Faso Laboratoire Sciences de la Vie et de la Terre (LaSVT) Universit Norbert ZONGO Koudougou Burkina Faso Virology Unit Institut Pasteur de Guine Conakry Guinea

Enteric viral pathogens are responsible for numerous epidemics associated with the consumption of fresh fruit and vegetable, whether raw or minimally processed. The aim of the present study was to assess agricultural practices and the presence of adenovirus (AdV) in fruits and vegetables, manure and irrigation wastewater sampled in the urban and peri-urban perimeters of Ouagadougou. A total of 286 samples including 30 lettuces, 42 tomatoes, 30 carrots, 30 strawberries, 74 manures and 80 wastewater samples were collected from four market garden sites in and around Ouagadougou. Nested PCR was performed with specific primers to detect adenoviruses (AdVs). A face-to-face survey was carried out using a questionnaire on market garden production practices. Overall, adenoviruses prevalence was 5.9% [IC95, 3.2% - 8.7%] in all samples analyzed. It was specifically 7.14% (3/42) from tomatoes, 6.7% (2/30) from lettuces, 20% (6/30) on strawberries and 7.5% (6/80) in irrigation water. The survey showed that irrigation water came from untreated sources (dam, well, canal) and then 52% of farms used untreated manure. No farms have implemented measures to limit access by domestic and wild animals. This work shows the presence of human adenoviruses in surface irrigation water and fresh produce, which is of concern when fresh produce is consumed raw. To reduce the public health risks associated with consuming these foods, it is essential to follow good hygiene and cultivation practices.

关键词： Adenovirus Raw Fruits and Vegetables Nested PCR Wastewater Manure Ouagadougou

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旋量理论及其在材料力学中的应用

力学与实践 2024年

作者：黄行蓉李敏 jean-pierre LAINE 北京航空航天大学中法工程师学院/国际通用工程学院北京航空航天大学航空科学与工程学院

旋量理论是为力学量身定制的数学工具，在描绘刚体运动时表现出独特优势。基于材料力学中的平截面假设，构件的截面运动可分解为形心位移以及截面绕形心的旋转，从而可将截面运动视为刚体运动，故可采用旋量理论刻画构件截面的运动和受... 详细信息

旋量理论是为力学量身定制的数学工具，在描绘刚体运动时表现出独特优势。基于材料力学中的平截面假设，构件的截面运动可分解为形心位移以及截面绕形心的旋转，从而可将截面运动视为刚体运动，故可采用旋量理论刻画构件截面的运动和受力。该描述方式在数学形式上具有统一性，在物理现象上能对应实际受载和变形的一般性，可将力学问题转变成基于旋量运算法则求解的数学问题。本研究期望能为我国材料力学教学提供新视角和新思路。

关键词：旋量理论材料力学数学工具

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

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 Al2O3 mainly in the scoriaceous facies (over 45% in grade), moderate in Fe2O3 (averaging 23.69%) and SiO2 (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 (Na2O, K2O) 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

Benefits of jejunostomy feeding in patients who underwent gastrectomy for cancer treatment

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World Journal of Gastrointestinal Surgery 2024年第8期16卷 2461-2473页

作者： Romain Jaquet Emmanuel Rivkine Nicole De Souza jean Roudié Department of Digestive and Visceral Surgery Nord Essonne Hospital Group-Longjumeau SiteLongjumeau 91160France Department of General and Digestive Surgery Pierre Zobda-Quitman HospitalUniversity Hospital CenterMartiniqueFranceFort de France 97261Martinique

BACKGROUND Gastric cancer is associated with significant undernutrition responsible for an increase in morbidity and mortality after *** To evaluate the impact of enteral nutrition by jejunostomy feeding in patients undergoing gastrectomy for *** Between 2003 and 2017,all patients undergoing gastrectomy for cancer treatment were included retrospectively.A group with jejunostomy(J+group)and a group without jejunostomy(J-group)were *** Of the 172 patients included,60 received ***,the two groups were comparable with respect to the nutritional parameters studied(body mass index,albumin,etc.).In the postoperative period,the J+group lost less weight and albumin:5.74±8.4 vs 9.86±7.5 kg(P=0.07)and 7.2±5.6 vs 14.7±12.7 g/L(P=0.16),*** morbidity was 25%in the J+group and 36.6%in the J-group(P=0.12).The J+group had fewer respiratory,infectious,and grade 3 complications:0%vs 5.4%(P=0.09),1.2%vs 9.3%(P=0.03),and 0%vs 4.7%(P=0.05),*** 30-day mortality was 6.7%in the J+group and 6.3%in the J-group(P=0.91).CONCLUSION Jejunostomy feeding after gastrectomy improves nutritional characteristics and decreases postoperative morbidity.A prospective study could confirm our results.

关键词： Feeding jejunostomy Gastric cancer Undernutrition Morbimortality Survival