检索结果-南通市图书馆

Superconductivity 2024年第1期9卷 50-64页

作者： Fabiano Carvalho de Castro sene Department of Industrial and Systems Engineering University of TennesseeKnoxvilleUnited States

Since the discovery of MgB_(2)as a superconductor,several research groups worldwide have studied the superconducting mechanisms due to the dual gap nature of MgB_(2),as well as attempted to produce such a compound in wires,tapes,bulks,and thin films for a plethora of *** MgB_(2)carries the promise of replacing Niobium‐based superconductors in low‐field applications,less‐than‐desirable performance and in‐operation stability has slowed down such a *** the properties and nature of the superconductivity of MgB_(2)are fairly known,the reproduction of its properties at manufacturing scales remains an unsolved ***,this manuscript presents a systematic review on fundamental properties,phase formation,growth kinetics,and superconducting properties of MgB_(2)‐based components such as multi‐and mono‐core wires,bulks,and thin ***,challenges,and shortcomings are utilized in consolidating research questions and directions pertaining to the manufacturing of MgB_(2)superconducting ***,we evaluate the technological readiness of MgB_(2)‐based devices for applications in fusion energy systems.

关键词： MgB_(2) Superconductor manufacturing Technology readiness Review Low‐Field applications

Photovoltaic waste management in sub-Saharan Africa:current practices in 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

Waste Disposal and Sustainable Energy 2024年第2期6卷 271-282页

作者： Kodami Badza Yrebegnan moussa Soro Marie Sawadogo Laboratoire Energies Renouvelables et EfficacitéEnergétique Institut International d'Ingenierie de I'Eau et de I'Environnement(2iE)01 BP 594 OuagadougouBurkina Faso

Sub-Saharan Africa is witnessing a proliferation of photovoltaic(PV)waste due to the increasing number of solar PV power *** waste(panels,batteries,electrical cables,mounting structures,and inverters)consists of elements such as mercury,cadmium,chromium,lead,copper,aluminum,fluorinated compounds,and plastics that are toxic to human health and the environment if a proper management system is not *** many studies worldwide have focused on PV waste management,very few have been conducted in sub-Saharan *** study aims to investigate the current PV waste management system in Burkina Faso,determine stakeholder profiles,and propose strategies to enhance the existing *** research,interviews,questionnaires,and field visits were used in the *** survey showed that young people,mainly under 30 years of age and with a primary education,dominate(70%)in terms of PV waste collection and repair activities,while the more technical recycling and export activities are carried out mainly(88%)by stakeholders older than 40 years and with a secondary education(60%).Among the older stakeholders,100%are aware of the hazardous nature of PV waste,whereas 36%are young *** an environmental perspective,the main source of contamination observed is the release of lead-rich sulfuric acids into water and soil during the collection and repair *** the recycling of batteries and electrical cables,toxic fumes are emitted into the air,and recycling residues rich in toxic substances are *** reduce risks to human health and the environment when managing PV waste,the introduction of legislation,the multiplication of collection points and appropriate infrastructures,the training and awareness-raising of stakeholders,and the extended responsibility of manufacturers are *** on the economic feasibility of setting up formal management structures are needed to complete this work.

关键词： Photovoltaic waste Sub-Saharan Africa Waste management Recycling Batteries Incineration

Surgical Treatment of the Upper Urinary Tract Lithiasis at the Urology Department of the Hopital General Idrissa Pouye

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 Urology 2024年第5期14卷 290-300页

作者： Mouhamadou Moustapha Mbodji Mohamed Jalloh Medina Ndoye Abdou Fall Cheikh Gassama Babou Sakho Serigne Mbacké Ndiaye moussa.sene Abdourahmane Diallo Issa Labou Lamine Niang Department of Urology and Andrology Hopital General Idrissa Pouye Dakar Senegal

Upper urinary tract lithiasis is a condition characterized by the presence of stones which is a stony concretion of crystallized substances in the kidney and/or ureter. Objective: The objective of this work is to study the epidemiological, clinical and therapeutic aspects of upper urinary tract stones on the one hand, then to compare the different types of surgical treatments and their results. Materials and Methods: This is a retrospective and descriptive study focusing on the surgical management of upper urinary tract stones, between January 2017 and December 2020, at the Urology department of the Hopital General Idrissa Pouye. Results: During the study period, 7.59% of surgical interventions performed were related to the treatment of upper urinary tract stones. Average age was 45.20 ± 16.4 years, the age group [41 - 60] years was more affected with 42.68%. A history of urolithiasis was present in 25.52% of cases. Lower back pain was present in 97.48% of cases. On URO-CT scan, the stone was located more at the level of the ureter (49.57%). The size between 10 to 15 mm was more frequent (30.96%) and the density greater than 1000 HU was more frequent (33.47%). The most used therapeutic procedure was ureteroscopy (52.08%), followed by PCNL (40.83%) and open surgery (7.08%). The success rate (stone free) was 93.68% for the URS, 89.36% for the PCNL. The length of hospital stay for open surgery was 6.76 ± 4.25, for PCNL 2.62 ± 2 days and for URS 1.75 ± 1.62 days. Postoperative complications were present in 23.52% for open surgery, 11.22% for PCNL and 8% for URS. Conclusion: Urolithiasis is constantly growing in our regions. Effective endourological treatment is increasingly replacing open surgery. However, global access to these new techniques in our regions is slow to be effective.

关键词： Endo-Urology Open Surgery Renal Lithiasis Ureteral Lithiasis URO-CT Scan

Saffron(Crocus sativus L.) stigmas as a potential natural additive to improve oxidative stability attributes of sunflower(Helianthus annuus L.) oil stored under different conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Grain & Oil Science and Technology 2024年第3期7卷 133-149页

作者： moussa Nid Ahmed Karima Abourat Jamila Gagour El Hassan Sakar Khalid Majourhat Said Gharby Biotechnology Analytical Sciences and Quality Control TeamPolydisciplinary Faculty of TaroudantUniversity Ibnou ZohrMorocco Laboratory of Biology Ecologyand HealthFSAbdelmalek Essaadi UniversityTetouanMorocco Geo-Bio-Environmental Engineering and Innovation Laboratory Polydisciplinary Faculty of TaroudantUniversity Ibnou ZohrAgadirMorocco

The aim of our study was to explore the antioxidant potential of Moroccan saffron stigmas(SS) and examine their performance as a natural antioxidant in enhancing the stability and quality properties of edible sunflower oil(SO), with a focus on understanding the critical importance of edible oil stability for predicting quality deterioration during storage. Bearing this in mind, our research was designed to compare the efficacy of three concentrations of dried SS(at 0.2%, 0.3%, and 0.6%) against tocobiol(a synthetic antioxidant) as a positive control(at 0.3% concentration). This comparison was conducted under three distinct storage conditions namely accelerated ageing(60 ℃), exposure to light at ambient temperature, and darkness, to evaluate their impact on preventing severe oxidation and extending oil shelf-life. Oxidation state evolution was evaluated through peroxide value(PV), free fatty acid(FFA), anisidine value(p-AV), K_(270)value(conjugated trienes), total oxidation index(TOTOX), iodine value(IV), and fatty acid composition(FA). Our results revealed notable differences in stability tracking parameters. Specifically, these parameters were higher in samples stored under accelerated conditions, followed by the samples stored in ambient light, while those stored in darkness showed the highest stability among the three storage conditions. Supplementation of sunflower oil with SS and tocobiol significantly enhanced its oxidation stability. Notably, SS exhibited exceptional effectiveness in stabilizing sunflower oil regardless of SS dose, with the highest efficacy observed at 0.6%. This was evidenced by the slower rate of oxidation parameters under various storage conditions, highlighting a superior antioxidant activity compared to both the non-enriched oil and tocobiol-enriched oil. Furthermore, saffron stigmas, used as a natural supplement,contributed to the preservation of polyunsaturated fatty acids, indicating its potential as a robust source of natural antioxi

关键词： Crocus sativus L. Helianthus annuus L. Saffron stigmas Shelf-life Sunflower oil Tocobiol

Effects of Prandtl and Jacob Numbers and Dimensionless Thermal Conductivity on Velocity Profiles in Media (Porous and Liquid)

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Physics 2024年第10期15卷 1603-1614页

作者： Momath Ndiaye Madialène sene Goumbo Ndiaye Department of Hydraulics Rural Engineering Machinery and Renewable Energy UFR Fundamental and Engineering Sciences University of Sine Saloum El Hadj Ibrahima NIASS Kaolack Senegal

In this present study, we analyzed the effects of Prandtl and Jacob numbers and dimensionless thermal conductivity on the velocity profiles in media (porous and liquid). The transfers in the porous medium and the liquid film are described respectively by the improved Wooding model and the classical boundary layer equations. The mesh of the digital domain is considered uniform in the transverse and longitudinal directions. The advection and diffusion terms are discretized with a back-centered and centered scheme respectively. The coupled systems of algebraic equations thus obtained are solved numerically using an iterative line-by-line relaxation method of the Gauss-Seidel type. The results show that the parameters relating to the thermal problem (the dimensionless thermal conductivity, the Prandtl (Pr) and Jacob (Ja) numbers) have no influence on the dimensionless speed, although the thermal and hydrodynamic problems are coupled. Via the heat balance equation. The results obtained show that the parameters relating to the thermal problem have no influence on the dimensionless speed, although the thermal and hydrodynamic problems are coupled via the heat balance equation. So, at first approximation with the chosen constants, we can solve the hydrodynamic problem independently of the thermal problem.

关键词： Condensation Implicit Finite Difference Thin Film Porous Material Model Wooding Vertical Wall

Clipping Effect on Growth and Plant Water Use Response to Diurnal Variation of Vapor Pressure Deficit in Cenchrus biflorus Roxb

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Agricultural Chemistry and Environment 2024年第2期13卷 183-191页

作者： moussa Oumarou Abdoulaye Issoufou Hassane Bil-Assanou Soulé moussa Mainassara Zaman-Allah Laboratory Ecology and Management of Sahelo-Saharan Biodiversity Department of Biology Faculty of Science and Techniques Andr&#233 Salifou University Zinder Niger Department of Biology Faculty of Sciences and Techniques Dan Dicko Dankoulodo University of Maradi Maradi Niger Department of Science and Technology of Plant Production Faculty of Agronomy and Environmental Sciences Dan Dicko Dankoulodo University of Maradi Maradi Niger

Cenchrus biflorus called Karangiya in the Hausa language is an annual pastoral grass which is a valuable herbaceous fodder in dry land region in the context of climate change. However, little is known about the plant water use under the effects of cut in West Africa Sahel like Niger where the plant is a multipurpose grass species. Therefore, this study investigated the impact of grazing (simulated by shoot cuts) on biomass production. Cenchrus biflorus Roxb was grown on field plots and in pots and subjected to shoot cuts at different levels (3 cm and 5 cm from soil surface). The effect of shoot cuts on drought tolerance was evaluated by assessing the response of transpiration to the diurnal variation of vapor pressure deficit (VPD). Results showed that the biomass production varied in response to shoot cuts depending on the culture system, and the level or frequency of cuts. The mean biomass production increased significantly especially in field plots for 5 cm cuts compared to those at 3 cm and the control treatment. In addition, transpiration was highly increased in response to the VPD increase. Shoot cuts significantly reduced transpiration, whatever the level, largely because they reduced leaf surface. We concluded that moderate grazing (cuts to 5cm) can improve biomass production and allow better adaptation to water deficit as they significantly reduced water loss through transpiration. The study recommends the cropping of the Cenchrus biflorus as climate solution as it performs better under water deficit for improving grazing resilience in Niger.

关键词： Cenchrus biflorus Biomass Vapor Pressure Deficit Cutting Grazing

Bearing Capacity Analysis of Spread Footing on Massif in the “Corniche Ouest” of the Dakar Peninsula (senegal, West Africa)

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 Civil Engineering 2024年第3期14卷 421-434页

作者： moussa Sawadogo Déthie Sarr Oustasse A. Sall Dpartement de Gotechnique L2M UFR Sciences de lIngnieur Universit Iba Der THIAM de This This Sngal Dpartement de Gnie-Civil UFR Sciences de lIngnieur Universit Iba Der THIAM de This This Sngal

This study presents various approaches to calculating the bearing capacity of spread footings applied to the rock mass of the western corniche at the tip of the Dakar peninsula. The bearing capacity was estimated using empirical, analytical and numerical approaches based on the parameters of the rock mass and the foundation. Laboratory tests were carried out on basanite, as well as on the other facies detected. The results of these studies give a range of allowable bearing capacity values varying between 1.92 and 11.39 MPa for the empirical methods and from 7.13 to 25.50 MPa for the analytical methods. A wide dispersion of results was observed according to the different approaches. This dispersion of results is explained by the use of different rock parameters depending on the method used. The allowable bearing capacity results obtained with varying approaches of calculation remain admissible to support the loads. On the other hand, the foundation calculations show acceptable settlement of the order of a millimeter for all the layers, especially in the thin clay layers resting on the bedrock at shallow depths, where the rigidity of the rock reduces settlement.

关键词： Peninsula of Dakar Bearing Capacity Basanites Rock Mass Spread Footings

Measuring Cognitive and Psychosocial Accessibility to Modern Contraception: A Comprehensive Framework

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7期16卷 578-591页

作者： Lonkila moussa Zan Clémentine Rossier Caroline Moreau INSD/ISSP Universit Joseph KI-ZERBO Ouagadougou Burkina Faso IDESO University of Geneva Geneva Switzerland Gates Institute Johns Hopkins University Baltimore United States

Nowadays, more than ever, the improvement of access to family planning (FP) has become an international goal. What constitutes access to FP? Current human rights-based contraceptive guidelines indicate that access begins as soon as women or couples express a desire to avoid pregnancy and their risk of unintended pregnancy is established. However, few studies have sought to define and measure cognitive and psychosocial access to contraception. To propose a comprehensive framework for the cognitive and psychosocial accessibility of contraception, we critically analyzed the literature on attitudes toward FP. The main dimensions that emerged were knowledge about FP, fear of side effects, approval of contraception, and contraceptive agency. We then identified and adjusted some questions that can capture these dimensions more comprehensively. As a result, we developed a questionnaire module comprising 15 questions, which was integrated into the 6th round of the PMA2020 survey in Burkina Faso in 2019. This research highlighted that previous studies have collected separate dimensions of contraceptive access, and the psychosocial dimension tended to be neglected. Our results demonstrate that it is possible to collect comprehensive data on cognitive and psychosocial dimensions of access to family planning.

关键词： Cognitive Dimensions Psychosocial Dimensions Contraception Intention To Use Side Effects

Study of the Characteristics of Large-Diameter Iron Bars Obtained by Rolling at the ODHAV Foundry in the Republic of Guinea

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science and Chemical Engineering 2024年第6期12卷 43-54页

作者： Alpha Issa Diallo Jean Ahmadou Kourouma Adama moussa Sakho Younoussa moussa Baldé Mamadou Madaniou Sow Alexandre Lucien Richard Mechanical Laboratory Higher Institut of Technology of Mamou Mamou Republic of Guinea Materials Laboratory of the Gamal Abdel Nasser University of Conakry Conakry Republic of Guinea Dpartment of Laboratory Technology Higher Institut of Technology of Mamou Mamou Republic of Guinea Department of Energy Science Higher Institut of Technology of Mamoun Mamou Republic of Guinea

This work consists of evaluating the quality of the mechanical parameters of large-diameter steels, i.e. 20, 25, 28 and 32, through a process of recycling scrap metal that fills garages, rubbish dumps, gutters and other abandoned sites, as well as imported concrete reinforcing steel sold in the Republic of Guinea. To carry out this important work, a number of mechanical tensile and bending tests and a microscopic analysis combining two devices, an electron microscope and a photographic camera, were carried out. The samples were taken from sampling areas in the major communes of Conakry, namely: Casse Sonfonia, Matoto and Kagbélen. The tensile strength values of the large dimensions 20, 25, 28 and 32 are given in the tables.

关键词： Recycled Scrap Large Diameter Rolling Tensile Testing Bending

Numerical Study of the Vibrations of Beams with Variable Stiffness under Impulsive or Harmonic Loading

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Engineering and Technology 2024年第2期12卷 401-425页

作者： moussa Sali Fabien Kenmogne Jean Bertin Nkibeu Abdou Njifenjou Laboratory of Materials Mechanics and Civil Engineering National Higher Polytechnic School of Maroua University of Maroua Maroua Cameroon Department of Civil Engineering Advanced Teachers Training College of the Technical Education University of Douala Douala Cameroon Laboratory Engineering Civil and Mechanics National Advanced School of Engineering University of Yaound&#233 1 Yaound&#233 Cameroon Laboratory of Energy Materials Modeling and Method (E3M) National Advanced School of Engineering University of Douala Douala Cameroon Laboratory of Mathematical Engineering and Information Systems National Advanced School of Engineering University of Yaound&#233 1 Yaound&#233 Cameroon

The behavior of beams with variable stiffness subjected to the action of variable loadings (impulse or harmonic) is analyzed in this paper using the successive approximation method. This successive approximation method is a technique for numerical integration of partial differential equations involving both the space and time, with well-known initial conditions on time and boundary conditions on the space. This technique, although having been applied to beams with constant stiffness, is new for the case of beams with variable stiffness, and it aims to use a quadratic parabola (in time) to approximate the solutions of the differential equations of dynamics. The spatial part is studied using the successive approximation method of the partial differential equations obtained, in order to transform them into a system of time-dependent ordinary differential equations. Thus, the integration algorithm using this technique is established and applied to examples of beams with variable stiffness, under variable loading, and with the different cases of supports chosen in the literature. We have thus calculated the cases of beams with constant or variable rigidity with articulated or embedded supports, subjected to the action of an instantaneous impulse and harmonic loads distributed over its entire length. In order to justify the robustness of the successive approximation method considered in this work, an example of an articulated beam with constant stiffness subjected to a distributed harmonic load was calculated analytically, and the results obtained compared to those found numerically for various steps (spatial h and temporal τ ¯ ) of calculus, and the difference between the values obtained by the two methods was small. For example for ( h=1/8 , τ ¯ =1/ 64 ), the difference between these values is 17%.

关键词： Successive Approximations Method Direct Integration Differential Equations Beams of Variable Stiffness Quadratic Parabola Impulse and Harmonic Loads