检索结果-南通市图书馆

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Prediction of Low Heating Value of Sugar Cane Bagasse as a Fuel for Industrial Boilers in the High Relative Humidity Region: Case of Cameroon

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Applied Sciences 2024年第6期14卷 1604-1624页

作者： pierre Kana-Donfack Maxell Tientcheu-Nsiewe Denis Tcheukam-Toko César Kapseu Department of Mechanical Engineering College of Technology University of Buea Buea Cameroon Department of Fundamental Sciences and Engineering Technology School of Chemical Engineering and Mineral Industries University of Ngaoudr Ngaoudr Cameroon Department of Process Engineering National School of Agro-Industrial Science University of Ngaoundr Ngaoudr Cameroon

Many attempts have been made to estimate calorific value of bagasse using mathematical equations, which were created based on data from proximate, ultimate, physical and chemical analysis. Questions have been raised on the applicability of these equations in different parts of the globe. This study was initiated to tackle these problems and also check the most suited mathematical models for the Law Heating Value of Cameroonian bagasse. Data and bagasse samples were collected at the Cameroonian sugarcane factory. The effects of cane variety, age of harvesting, source, moisture content, and sucrose on the LHV of Cameroon bagasse have been tested. It was shown that humidity does not change within a variety, but changes from the dry season to the rainy season;the sugar in the rainy season is significantly different from that collected in the dry season. Samples of the same variety have identical LHV. LHV in the dry season is significantly different from LHV in the rainy season. According to the fact that this study was done for cane with different ages of harvesting, the maturity of Cameroonian sugarcane does not affect LHV of bagasse. Tree selected models are much superior tool for the prediction of the LHV for bagasse in Cameroon compared to others. The standard deviation of these validated models is around 200 kJ/kg compared to the experimental. Thus, the models determined in foreign countries, are not necessarily applicable in predicting the LHV of bagasse in other countries with the same accuracy as that in their native country. There was linear relationship between humidity, ash and sugar content in the bagasse. It is possible to build models based on data from physical composition of bagasse using regression analysis.

关键词： Sugarcane Bagasse Relative Humidity Ash Low Heating Value

Fluctuating Asymmetry of Elopes lacerta (Valenciennes, 1847) Otoliths in the Western African Waters

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Marine Science 2024年第3期14卷 41-62页

作者： Madel Floriane Adjibayo Houeto Marwa Mejri Malek Tazarki Marius Sounouvou Nicolas Andrialovanirina Meriem Ben Ghorbel pierre Dossou-Yovo Abdellah Chalh pierre Quignard Monia Trabelsi Kélig Mahé Laboratory of Ecology Biology and Physiology of Aquatic Organisms Faculty of Sciences of Tunis University of Tunis El Manar Tunis Tunisia Institute of Mathematics and Physical Sciences University of Abomey-Calavi (UAC) Abomey-Calavi Benin IFREMER Unit HMMN Halieutic Resources Laboratory Boulogne-sur-Mer France Laboratory for Research into the Processing and Conservation of Fishery Products (LAREPROH) University of Abomey-Calavi (UAC) Abomey-Calavi Benin Unit of Population Genetics and Biological Resources Faculty of Sciences of Tunis University of Tunis El Manar Tunis Tunisia Laboratoire dIchtyologie Universit Montpellier Montpellier France

The importance of this study lies in the in-depth exploration of the ecological diversity of otoliths in Elopes lacerta, based on the analysis of data from 260 individuals collected from various sites, including the Porto Novo lagoon, the Cotonou lagoon, Lake Nokou, and the Atlantic coast in southern Benin. The results highlight significant variations in otolith morphology, establishing relevant links with the biological parameters of the fish at each site. Exploration of the asymmetry between the right and left sides reveals notable distinctions between these two aspects. Analysis of otolith shape thus emerges as a valuable tool for discriminating between stocks and providing a better understanding of ecological variations. The local diversity observed highlights the crucial importance of implementing adaptive management strategies to ensure effective conservation of the species and its habitat.

关键词： Analysis Porto-Novo Lagoon Cotonou Lagoon Lake Nokoué Coast Atlantic

Petrology of Spinel-Lherzolite Xenoliths from Mazéléand Others Northen Xenoliths Localities of Cameroon Volcanic Line: Exchange Reactions and Equilibrium State

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Geology 2024年第5期14卷 629-653页

作者： Nguihdama Dagwai Kamgang pierre Mbowou Gbambié Isaac Bertrand Chazot Gilles Ngounouno Ismaïla Department of Life and Earth Sciences Higher Teachers&#8217 Training College University of Maroua Maroua Cameroon Department of Earth Sciences Faculty of Science University of Yaound&#233 1 Yaound&#233 Cameroon Department of Mineral Prospecting and Exploration Technologies School of Geology and Mining Engineering University of Ngaoundere Meiganga Cameroon Ocean Geosciences Laboratory European University Institute of the Sea (IUEM) Brest France

The alkaline volcanism of the Cameroon Volcanic Line in its northern domain has raised many fresh enclaves of peridotites. The samples selected come from five (05) different localities (Liri, in the plateau of Kapsiki, Mazélé in the NE of Ngaoundéré, Tello and Ganguiré in the SE of Ngaoundéré and Likok, locality located in the west of Ngaoundé). The peridotite enclaves of the above localities show restricted mineralogical variation. Most are four-phase spinel-lherzolites, indicating that this is the main lithology that forms the lithospheric mantle below the shallow zone. No traces of garnet or primary plagioclase were detected, which strongly limits the depth range from which the rock fragments were sampled. The textures and the wide equilibrium temperatures (884˚C - 1115˚C) indicate also entrainment of lherzolite xenoliths from shallow depths within the lithosphere and the presence of mantle diapirism. The exchange reactions and equilibrium state established in this work make it possible to characterize the chemical composition of the upper mantle of each region and test the equilibrium state of the phases between them. Variations of major oxides and incompatible elemental concentrations in clinopyroxene indicate a primary control by partial melting. The absence of typical “metasomatic” minerals, low equilibration temperatures and enriched LREE patterns indicate that the upper mantle below septentrional crust of Cameroun underwent an event of cryptic metasomatic enrichment prior to partial melting. The distinctive chemical features, LREE enrichment, strong U, Ce and Pr, depletion relative to Ba, Nb, La, Pb, and T, fractionation of Zr and Hf and therefore ligh high Zr/Hf ratio, low La/Yb, Nb/La and Ti/Eu are all results of interaction of refractory peridotite residues with carbonatite melts.

关键词： Xenoliths Upper Mantle Northern Region Adamawa Cameroon Volcanic Line Exchange Reaction

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Palaeogene Sandstones of the Manika Plateau in Kolwezi (DR Congo): Sedimentological and Geochemical Characterization, Provenance, Palaeoalteration and Tectonic Context

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Geology 2024年第7期14卷 705-722页

作者： pierre T. Mashala Faidance Mashauri Samy M. Malango Christian K. Mulopwe Department of Geology University of Lubumbashi Haut-Katanga DR Congo Department of Geology University of Ul Haut-Ul DR Congo Department of Geology and Technology University of Kolwezi Lualaba DR Congo

This work presents a study of the Paleogene sandstones of the Manika plateau in Kolwezi, DR Congo. These sandstones belong to the “Grès polymorphes” group, which together with the overlying “Sables ocre” makes up the Kalahari Supergroup. Sedimentological and geochemical analyses have enabled us to characterize these sandstones and determine their origin, the conditions of their formation and the tectonic context in which they were developed. The results show that the sandstones are quartz arenites with a high level of mineralogical, textural and chemical maturity. They are recycled sandstones, formed in an intracratonic sedimentary basin, in the context of a passive continental margin, after a long fluvial transport of sediments. These sandstones initially come from intense alteration of magmatic rocks with felsic composition, mainly tonalite-trondhjemite-granodiorite (TTG) complexes, in hot, humid palaeoclimatic conditions and oxidizing environments.

关键词： Sandstone Sedimentology Geochemistry Palaeoalteration Tectonic Context Manika Plateau DR Congo

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Formulation of Infant Flours Based on Fonio Enriched with Bambara Groundnut Anacardium (Cashew) and African Locust Bean Fruit Pulp

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences 2024年第9期15卷 1071-1088页

作者： Lawrence Roselynn Kra KouaKou pierre Martial Thierry Akely Albarin Grodji Gbogouri Françoise Kouame Laboratory of Food Biochemistry and Tropical Product Technologies UFR of Food Sciences and Technology Nangui-Abrogoua University Abidjan Ivory Coast Department of Science et Technologie Section (SVT) Ecole Normale Suprieure Abidjan Cte dIvoire

Infant malnutrition is a significant issue in Côte d’Ivoire, and this study aims to address it by formulating infant flours using local ingredients. Fermentation, germination, and malting methods were used to enhance the quality of six formulated flours, all based on Fonio and supplemented with Bambara groundnut, African locust bean fruit pulp, and cashew kernels. Results showed that Fonio had the highest carbohydrate content, while Bambara groundnut and Cashew kernels were rich in protein and lipid content. African locust bean fruit pulp was rich in fiber and Vitamin C, with a high β-carotene value. The cashew kernel had the highest energy value. Regarding mineral composition, African locust bean fruit pulp had the highest potassium content, while Bambara groundnut and African locust bean fruit pulp were rich in sodium. Cashew kernel and Fonio had higher iron and calcium content. Bambara groundnut had a higher zinc content, while cashew kernel had a higher magnesium content. The formulated flours made from fermented Fonio grains and enriched with Bambara groundnut, African locust bean fruit pulp, and cashew kernel had varying protein, fiber, carbohydrate, ash, and fat contents. The flour formulated with sprouted Fonio and enriched with the same ingredients had higher protein content and energy value than the other fermented seed-based flours. The mixed flours produced with fermented seeds and the flour produced from sprouted seeds met international standards. Overall, these findings offer valuable insights into the nutritional composition of the formulated flours and their potential to combat infant malnutrition in Côte d’Ivoire.

关键词： Infant Flours Formulation Fonio Groundnut African Locust Bean Fruit Pulp

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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