检索结果-南通市图书馆

Energy and Power Engineering 2020年第1期12卷 1-15页

作者： Ousmane sow Mamadou Lamine Ba Mohamed Abderrahim Ould el Moujtaba Youssou Traore el hadji sow Cheikh Tidiane Sarr Masse Samba Diop Grégoire Sissoko University Institute of Technology University of Thiès Thiès Sénégal Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Senegal Ecole Polytechnique de Thiès Thiès Sénégal

In this work, we study the characteristics I-V and P-V of a silicon solar cell as well as its fill factor, its electrical power from the optimum thickness obtained in the base under variation of the irradiation energy flow of charged particles. The recombination velocity at the junction corresponding to the maximum power point was also deduced.

关键词： Silicon Solar Cell Flow Irradiation Energy Recombination Velocity Optimum Base Thickness

Surface Recombination Concept as Applied to Determinate Silicon Solar Cell Base Optimum Thickness with Doping Level Effect

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 Condensed Matter Physics 2019年第4期9卷 102-111页

作者： Masse Samba Diop Hamet Yoro Ba Ndeye Thiam Ibrahima Diatta Youssou Traore Mamadou Lamine Ba el hadji sow Oulymata Mballo Grégoire Sissoko Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Senegal Laboratory of Sciences and Techniques of Water and Environment Polytechnic School of Thiès Thiès Senegal.

New expressions of back surface recombination of excess minority carriers in the base of silicon solar are expressed dependent on both, the thickness and the diffusion coefficient which is in relationship with the doping rate. The optimum thickness thus obtained from the base of the solar cell allows the saving of the amount of material needed in its manufacture without reducing its efficiency.

关键词： Silicon Solar Cell Surface Recombination Velocity Diffusion Coefficient Doping Rate Base Thickness

AC Recombination Velocity in the Back Surface of a Lamella Silicon Solar Cell under Temperature

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 Modern Physics 2019年第10期10卷 1235-1246页

作者： Youssou Traore Ndeye Thiam Moustapha Thiame Amary Thiam Mamadou Lamine Ba Marcel Sitor Diouf Ibrahima Diatta Oulymata Mballo el hadji sow Mamadou Wade Grégoire Sissoko Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Senegal Laboratory of Sciences and Techniques of Water and Environment Polytechnic School of Thiès Thiès Senegal University Assane SECK Ziguinchor Senegal

The ac recombination velocity of the excess minority carriers, in the back surface of a silicon solar cell with a vertical junction connected in series, is developed through Einstein’s law giving the diffusion coefficient of minority carriers according to temperature, through mobility. The frequency spectrum of both, amplitude and phase, are produced for the diffusion coefficient and the recombination velocity in the rear face, in order to identify the parameters of equivalent electric models.

关键词： Vertical Multi-Junctions Solar Cell AC Back Surface Recombination Velocity Temperature Bode and Nyquist Diagrams

The Various Complications Associated with Use of Silicone Oil in Rhegmatogenous Retinal Detachment (RRD) Surgery via Three-Port Vitrectomy (3PV): A Retrospective Study at the Ophthalmology Center of Abass Ndao Hospital

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 Ophthalmology 2024年第3期14卷 250-256页

作者： Soda Mbaye el hadji Malick Sy Aïssatou Aw Papa Amadou Ndiaye Abass Ndao University Hospital Center Dakar Senegal

Introduction: RRD (Rhegmatogenous Retinal Detachment) is a separation between the neuroepithelium and the pigment epithelium due to the passage of fluid through a retinal dehiscence. It constitutes a major ophthalmologic emergency. Its management is primarily surgical, either through external or internal approaches, with tamponade using gas or silicone oil. The purpose of this study was to report the various complications associated with the use of silicone oil in vitreoretinal surgery. Patients et methods: We conducted a retrospective, descriptive, and analytical study from October 1, 2020, to October 31, 2023, which included all patients who underwent surgery for RRD using three-port vitrectomy (3PV) with tamponade using 1000 centistoke silicone oil (Group 1) and 5000 centistoke silicone oil (Group 2). All patients underwent a complete ophthalmologic examination and were operated on by the same surgeon. Data analysis was performed using Excel software. Results: Overall, 31 patient files representing 33 eyes were collected, with a mean age of 48.83 years and a sex ratio of 4.16. Group 1 consisted of 16 eyes (48.48%), and Group 2 consisted of 17 eyes (51.51%). The different complications observed were cataracts in all phakic subjects, accounting for 57.57%;ocular hypertonia in 69.69% (27.27% in Group 1;42.42% in Group 2);anterior chamber silicone oil migration in 24.24% (9.09% in Group 1;15.15% in Group 2);recurrence of retinal detachment in 21.21% (6.06% in Group 1;15.15% in Group 2);and silicone oil emulsification in 24.24% (15.15% in Group 1;9.09% in Group 2). Additionally, there was one case of corneal degeneration in Group 1. Conclusion: Silicone oil is an effective tamponade agent used in the treatment of retinal detachments. Close patient follow-up is necessary due to the complications associated with its use, which can occur either early or late after surgery.

关键词： Silicone Cataracts OHT Emulsifications

Regional Climate Models in the Simulation of the Drought of the 1970’s and 1980’s Years in Senegal (In 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

Journal of Water Resource and Protection 2024年第9期16卷 585-604页

作者： Mamadou Sarr Adoum Mahamat Moussa Malick Wade el hadji Deme Bouya Diop Laboratoire des Sciences de lAtmosphre et des Ocans Matriaux-Energies-Dispositifs (LSAO-MED) Universit Gaston Berger Saint-Louis Sngal Ecole Nationale Suprieur des TIC (ENASTIC) NDjamena Tchad Laboratoire dEtudes et de Recherches en Statistique et Dveloppement (LERSTAD) Universit Gaston Berger Saint-Louis Sngal

West Africa was hit by an unprecedented drought in the 1970’s and 1980’s years, with dramatic consequences for surface and groundwater resources. In the context of climate change, there are many studies for the prediction of the increase in the occurrence of these droughts. To predict this situation in the Senegalese region, it is necessary to use regional climate models, which carrying out the study. This work deals with the interest to examine the capacity of the RCMs (regional climate models) in order to reproduce the deficit on the 1970’s year rainfall in Senegal. In this work, we used daily precipitation data from five (5) regional climate models to characterize the droughts in Senegal by using the SPI (Standardized Precipitation Index) on different time scales (3, 6, 12 and 24 months). For this purpose, the index was calculated over two distinct periods: 1951-1969 and 1970-1990. The results show that the period 1970-1990 was drier than the period 1951-1969. For the zonal average, the results show that the North of Senegal was more affected by this deficit rainfall than the South part. The analysis of the interannual variability of rainfall for some stations in Senegal shows that the drought did not start at the same time throughout the zone.

关键词： Climate Change Drought SPI (Standardised Precipitation Index) Senegal

From Fostering to Delusional Disorder of Filiation

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 Psychiatry 2024年第4期14卷 283-286页

作者： Momar Camara Wissem Masmoudi el hadji Makhtar Ba Sokhna Seck Maïmouna Dieye Aïda Sylla Department of Psychiatry and Medical Psychology Cheikh Anta Diop University Dakar Senegal Thiaroye National Psychiatric Hospital Center Dakar Senegal Fann National University Hospital Center Dakar Senegal Albert Royer Childrens Hospital Dakar Senegal

Introduction: Fostering is a widespread practice in West Africa. It played an essential role in the circulation of children. The failure of its community regulation, not compensated by a legal framework, has made its practice precarious. Observation: A case study was conducted on Dior, who was hospitalised in a psychiatric ward for a delusional disorder of filiation. Dior was entrusted to her maternal grandmother and aunt at ages 2 and 9. During these fosterings, the place of the symbolic father was not substituted, causing a void that challenged her imagination. The outcome was an inscription in a genealogy where she had found herself with prestigious parents. Discussion: Fostering has strongly disrupted the family dynamics in Dior’s case. One of her options was to assume the paternal function, the use of which was perceived as a defiance or even a transgression. This same function would be a starting point of a psychosis whose filial character would only be an attempt at rectification where reality and imagination collide. Conclusion: Our study reveals the importance of stable parental figures at stake in fostering contexts, which constitute a risk factor for the development of a subsequent psychosis.

关键词： Delusional Disorder of Filiation Psychopathology Interactions Fostering Family

Stability analysis of a time-delayed Van der Pol–Helmholtz–Duffing oscillator in fractal space with a non-perturbative approach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第4期76卷 22-31页

作者： Yusry O el-Dib Department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt

The time-delayed fractal Van der Pol–Helmholtz–Duffing(VPHD)oscillator is the subject of this paper,which explores its mechanisms and highlights its stability *** time-delayed technologies are currently garnering significant attention,the focus of this research remains crucially relevant.A non-perturbative approach is employed to refine and set the stage for the system under *** innovative methodologies introduced yield an equivalent linear differential equation,mirroring the inherent nonlinearities of the ***,the incorporation of quadratic nonlinearity into the frequency formula represents a cutting-edge *** analytical solution's validity is corroborated using a numerical *** conditions are ascertained through the residual Galerkin ***,it is observed that the delay parameter,in the context of the fractal system,reverses its stabilizing influence,impacting both the amplitude of delayed velocity and the *** analytical solution's precision is underscored by its close alignment with numerical ***,the study reveals that fractal characteristics emulate damping *** its applicability across diverse nonlinear dynamical systems,this non-perturbative approach emerges as a promising avenue for future research.

关键词： Van der Pol-Helmholtz-Duffing oscillator fractal space time-delay non-perturbative approach stability analysis el-Dib's frequency formula

Eyelid Wounds: Epidemiological, Clinical and Etiological Aspects

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

Open Journal of Ophthalmology 2024年第1期14卷 55-62页

作者： Aly Mbara Ka Jean Pierre Diagne Aissatou Aw el hadji Malick Sy Soda Mbaye Hawo Madina Diallo Audrey Samra Aboubacry Sadikh sow Joseph Matar Mass Ndiaye Ousmane Ndiaga Senghor Lamine Ndiaye Mohamed Ndiaye Serigne Sohibou Gaye Papa Amadou Ndiaye Ophthalmology Department of Abass Ndao Hospital Dakar Senegal Ophthalmology Department of Aristide Le Dantec Hospital Dakar Senegal

Purpose: The aim is to show epidemiological, clinical and etiological characteristics of palpebral wounds. Methodology: This was a retrospective study focusing on patients with an eyelid wound, over a 10-year period from 2012 to 2021. We collected and analyzed the data using Excel. Results: The frequency of eyelid wounds was 0.1%. The average age of our patients was 19.38 years with a range of 1 and 62 years. The sex ratio was 3.7. Eighty-one percent of patients lived in Dakar. Fifty-seven percent (57%) of patients consulted less than 24 hours after the trauma and 7% of patients on D1. The circumstances were brawls (11%), domestic accidents (9%), road accidents (6%), and work accidents (6%). We noted 1 case of dog bite. Thirteen patients presented with post-traumatic decreased visual acuity. Involvement of the isolated upper eyelid was noted in 40% of cases and both eyelids in 15% of cases. Involvement of the lacrimal ducts was noted in 17% of cases, and that of the free edge in 21% of cases. Eyelid wounds were associated with eyeball damage in 21% of cases. Various associated lesions were observed. Ninety-one percent of patients received surgical treatment. Three cases of superinfections, 1 case of conjunctival granuloma and 1 case of phthysis of the eyeball with postoperative retinal detachment were noted. Conclusion: Eyelid sores are relatively common in our context. They require rapid surgical treatment in order to preserve the functional and aesthetic prognosis. .

关键词： Eyelid Wounds Epidemiology Clinic Etiologies

Experimental Study of the Anti-Corrosion Performance of Montmorillonite K-10 on Rebar in HCl Environment: Application in Mortar for the Rehabilitation of Reinforced Concrete Degraded by Corrosion

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2期14卷 155-167页

作者： Malang Bodian Mariétou Barro Diop-Fall Dame Keinde el-hadji Dieye Modou Gningue Diop Modou Fall Laboratoire de Chimie Physique Organique et dAnalyse Environnementales (LCPOAE) Dpartement de Chimie Univ Cheikh Anta Diop de Dakar Dakar Senegal Laboratoire de Matriaux de Gnie Civil (LMGC) Ecole Suprieure Polytechnique de Dakar Univ Cheikh Anta Diop Dakar Sngal

This work first investigates the corrosion-inhibiting behavior of montmorillonite K-10 on reinforcing steel. The corrosion-inhibiting power of the clay (Montmorillonite) is determined in a medium HCl (C = 1N) using free corrosion potential monitoring, Tafel potentiodynamic polarization curves and electrochemical impedance spectroscopy. The results of this study showed a satisfactory corrosion-inhibiting efficiency of around 72.665% for the optimum content of 1%. This is due to the presence of a stable oxide layer that protects the metal against corrosion. To validate the concept of montmorillonite as a corrosion inhibitor in repair mortar, we now turn to the influence of montmorillonite on the mechanical properties of mortars in the hardened state. In this part, montmorillonite K-10 is added to the mortar by partial substitution of the cement by 5% and 10% of the cement mass. The aim of this study is to ensure that the addition of this clay to the mortar composition will not have a negative effect on its compressive and flexural strengths. The results of the compression and flexural tests showed that the presence of montmorillonite in the mortar improved flexural and compressive strengths for the different compositions studied.

关键词： Clay Reinforced Concrete Corrosion Inhibitor Rehabilitation electrochemical Methods

Comparison between seismic analysis of twisting and regular 52-story towers considering soil-structure interaction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2024年第3期23卷 663-675页

作者： Mohamed Naguib Abouelsaad Mohammed Shaaban Salah el Bagalaty Mohamed E.el Madawy Structural Engineering Department Faculty of EngineeringMansura UniversityMansoura 35511Egypt Faculty of Engineering Delta University for Science and TechnologyGamasa 35712Egypt

A dynamic analysis of both twisting and regular towers is carried out to determine the results of considering soil-structure interaction(SSI)on high-rise *** addition,the difference between the seismic performance of using twisting towers over regular ones is *** twisting tower is a simulation of the Evolution Tower(Moscow).The towers’skeletons consist of RC elements and rest on a reinforced concrete piled-raft *** soil model is considered as multi-layered with the same soil properties as the zone chosen for the analysis(New Mansoura City,Egypt).The only difference between both towers is their shape in *** whole system is modelled and analyzed in a single step as one full 3D model,which is known as the direct approach in *** analyses are carried out using finite-element software(Midas GTS NX).Dynamic output responses due to three records of seismic loads are proposed and presented in some *** on the results,it is concluded that SSI has a considerable effect on the dynamic response of tall buildings mainly because of the foundation flexibility,as it leads to lengthening the vibration period,increasing the story drift and the base shear for both cases.

关键词： soil-structure interaction seismic analysis twisting towers base shear story drift finite element method Midas GTS NX