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Diffusion Coefficient in Silicon Solar Cell with Applied Magnetic Field and under Frequency: Electric Equivalent Circuits

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World Journal of Condensed Matter Physics 2014年第2期4卷 84-92页

作者： Amadou Diao ndeye thiam Martial Zoungrana Gokhan Sahin Mor Ndiaye Grégoire Sissoko Laboratory of Environment Materials Physics Department Training and Research Unit in Applied Science University of Ouagadougou Ouagadougou Burkina Faso Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Sénégal

In this paper, a theory on the determination of the diffusion coefficient of excess minority carriers in the base of a silicon solar cell is presented. The diffusion coefficient expression has been established and is related to both frequency modulation and applied magnetic field;the study is then carried out using the impedance spectroscopy method and Bode diagrams. From the diffusion coefficient, we deduced the diffusion length and the minority carriers’ mobility. Electric parameters were derived from the diffusion coefficient equivalent circuits.

关键词： Solar Cell Magnetic Field Frequency Modulation Diffusion Coefficient

Influence of Temperature and Frequency on Minority Carrier Diffusion Coefficient in a Silicon Solar Cell under Magnetic Field

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Energy and Power Engineering 2019年第10期11卷 355-361页

作者： Seydina Diouf Mor Ndiaye ndeye thiam Youssou Traore Mamadou Lamine Ba Ibrahima Diatta Marcel Sitor Diouf Oulimata Mballo Amary thiam Ibrahima Ly Grégoire Sissoko Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Senegal Electromechanical Department Polytechnic School of Thiès Thiès Senegal.

In this study, the effects of temperature and frequency on minority carrier diffusion coefficient in silicon solar cell under a magnetic field are presented. Using two methods (analytic and graphical), the optimum temperature corresponding to maximum diffusion coefficient is determined versus cyclotronic frequency and magnetic field.

关键词： Solar Cell Diffusion Coefficient Temperature Magnetic Field Frequency

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

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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

Darier-Ferrand Dermofibrosarcoma: A Case Report of a Cervical Localization

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International Journal of Otolaryngology and Head & Neck Surgery 2023年第5期12卷 317-325页

作者： Aminata Mbaye Ndiassé Ndiaye ndeye Fatou thiam Ousmane Sano Rachid Vitamine Mouhamed Salem Ould Abderrahmane Maïmouna Diagne Malick Ndiaye ENT Department Thiès Regional Hospital Thies Senegal ENT Department Ouakam Military Hospital Dakar Senegal Radiology Department Thies Regional Hospital Thies Senegal ENT Department Diamniadio Children’s Hospital Dakar Senegal

Darier-Ferrand dermatofibrosarcoma (DFS) is a cutaneous mesenchymal tumor of intermediate malignancy. It is a rare but not exceptional tumor, accounting for 0.1% of malignant skin tumors. Histological examination is essential for diagnosis. Wide surgical excision is the standard treatment. DFS is a tumor whose prognosis and evolutionary risk are mainly linked to the delay in diagnosis and the quality of the first excision. Late diagnosis makes excision and reconstruction surgery difficult. The chances of recovery in the case of well-performed primary surgery are significantly greater than in the case of salvage surgery. To improve prognosis, early, codified, multidisciplinary management is essential. In our African context, and especially in the case of patients living in rural areas, errant diagnoses are often found hence the importance of raising awareness and providing information to healthcare personnel. We report a case of an enlarged left supraclavicular Darier-Ferrand dermatofibrosarcoma. The patient had come for a late consultation at a stage when the tumour was large. The CT scan was a great help in the pre-operative phase. The patient underwent complete surgical excision, the postoperative course was straightforward and the histology of the surgical specimen confirmed the diagnosis. The resection margins were healthy. The patient is alive at one year with no recurrence or metastasis.

关键词： Cervical Localization Dermatofibrosarcoma Skin Tumor Wide Surgery

Base Thickness Optimization of a (n+-p-p+) Silicon Solar Cell in Static Mode under Irradiation of Charged Particles

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Journal of Electromagnetic Analysis and Applications 2019年第10期11卷 173-185页

作者： Mamadou Lamine Ba ndeye thiam Moustapha thiame Youssou Traore Masse Samba Diop Mamour Ba Cheikh Tidiane Sarr Mamadou Wade Gregoire Sissoko Laboratory of Sciences and Techniques of Water and Environment Polytechnic School of Thiès Thiès Senegal Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Senegal.

In this work, we propose a method to determinate the optimum thickness of a monofacial silicon solar cell under irradiation. The expressions of back surface recombination velocity depending the damage coefficient (kl) and irradiation energy (øp) are established. From their plots, base optimum thickness is deduced from the intercept points of the curves. The short-circuit currents Jsc0 and Jsc1 corresponding to the recombination velocity Sb0 and Sb1 are determinated and a correlation between the irradiation energy, the damage coefficient and optimum thickness of the base is established.

关键词： Silicon Solar Cell Irradiation Recombination Velocity Base Thickness

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

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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

Resistance to Anti-Thyroid Drugs in Graves’ Disease: Clinical-Biological Characteristics and Alternative Therapy in Tropical Area

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Open Journal of Endocrine and Metabolic Diseases 2020年第11期10卷 147-153页

作者： Ngoné Diaba Diack Nafy Ndiaye Mbaye Sene Mamadou Ba ndeye Fatou thiam Khadidja Samb Pape Momar Guisse Sokhna Awa Balla Sall Aida Diop Diene Marylin Zohoun Yakham Mohamed Leye Abdoulaye Leye Department of Endocrinology Pikine Teaching Hospital Cheikh Anta Diop University Dakar Senegal Department of Otorhinolaryngology Military Hospital of Ouakam Dakar Senegal

Background: Resistance to anti-thyroid drugs (ATDs) is a rare entity recently described. We report two African observations in the treatment of Graves’ disease. Case 1: A 19-year-old Senegalese woman presented on admission with thyrotoxicosis syndrome associated with diffuse goitre and Grave’s orbitopathy. TSH levels were low (0.005 mIU/ml;N = 0.27 - 4.20) and fT4 elevated (60 pmol/L;N = 12 - 22]. Combination therapy with propranolol (40 mg/day) and carbimazole (starting dose of 45 mg/day and increased to 60 mg/day) was initiated. In view of the persistence of symptoms despite good therapeutic compliance, carbimazole was replaced by methimazole with an initial starting dose of 40 mg/day, followed by 60 mg/day. Despite the change in therapy, clinical symptoms of thyrotoxicosis persisted, and fT4 levels remained elevated. The patient was diagnosed with resistance to ATDs in Graves’ disease. Total thyroidectomy following 10 days of preoperative preparation with 1% Lugol’s solution was performed successfully. Case 2: A 22-year-old woman was referred for continued management of Graves’ disease with elevated thyroid-stimulating hormone receptor antibody (TRAb) levels (34 UI/mL;N Conclusion: Resistance to ATDs complicates the management

关键词： Resistance Antithyroid Drugs Graves’ Disease Lugol’s Solution Africa Senegal

Profile of Amoebic vs. Pyogenic Liver Abscess and Comparison of Demographical, Clinical, Radiological, and Laboratory Profiles of These Patients from Three Secondary Care Centers in Senegal

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Advances in Infectious Diseases 2024年第3期14卷 595-605页

作者： Agbogbenkou Tevi Dela-Dem Lawson Daouda Thioub Ndiaga Mbengue ndeye Amy Sarr Sylvie Audrey Diop Service des maladies Infectieuses et tropicales de lHpital de Tivaouane Tivaouane Sngal UFR des sciences de la sante de lUniversit Iba Der thiam de This This Sngal

Background: Liver abscess (LA) is a suppurated collection in the hepatic parenchyma. In Africa, liver abscesses are most often of amoebic origin, but more recently, the rate of pyogenic liver abscesses (PLA) has increased. Objective: to assess the epidemiological characteristics, clinical features, biological radiological findings, and outcomes of patients with PLA and with amebic liver abscess (ALA) in order to determine the potential factors that may help improve diagnosis and treatment for LA in the context of secondary care centers with limited medical supports. Methods: Retrospective review of LA diagnosed and treated at three secondary care centers in Thiès over 11 years. Results: 61 patients, were included, 52.45% had ALA and 47.54% had PLA. Males were predominant (79.31% in PLA vs 65.63% in ALA, p = 0.2). The median age was 38 years for the PLA group vs 39 years for the ALA group (p = 0.4). In both groups, the most common symptom was right upper abdominal pain (81.97%), hepatomegaly (81.97%). The PLA group had a higher prevalence of fever (79.31% vs 46.88%, p = 0,009), chills (51.72% vs 18.75%, p = 0.007), right basi-thoracic pain (55.17% vs 28.13%, p = 0.032), and jaundice (55.17% vs 28%, p = 0.032). There was no difference in radiological features between PLA and ALA. Patients with PLA had a higher level of White blood cell (20.600 vs 15.400, p = 0.014). The most common bacteria identified in PLA were Escherichia coli (58.8%). All patients had received antibiotic therapy, which was combined with aspiration puncture (37.3%), transcutaneous drainage (43.3%), and surgery (9.0%). Seven patients had received antibiotic therapy alone and all had amoebic abscesses. Elsewhere, the occurrence of complications was higher in PLA cases (75.86% vs 37.5%, p = 0.003). The overall hospital mortality rate was 13.11%, higher in cases of PLA (24.14% vs 3.13%, p = 0.022). Conclusion: Clinical and biological features were more severe in PLA. But radiological features cannot be

关键词： Profile Liver Abscess Amoebic Pyogenic Senegal

Study of Descriptive Determinants of Moral Harassment at Work in a Factory in Senegal

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Health 2020年第2期12卷 106-117页

作者： Abou Sy Ekué Kafui Kokou Jean Augustin Diegane Tine ndeye Amelie Makareme Sy Aissatou Diallo Ibrahima Seck Mor Ndiaye Taiwo Lateef Sheikh Mamadou Habib thiam Department of Psychiatry University Cheikh Anta DIOP Dakar Senegal Department of Public Health University Cheikh Anta DIOP Dakar Senegal Department of Labor Medicine University Cheikh Anta DIOP Dakar Senegal Department of Psychiatry Ahmadu Bello University Zaria Nigeria

Introduction: Globalization and the attendant contemporary system of work organization, industrial competitiveness and workplace hostility could be a source of stress. Behaviors considered to be hostile tend to constitute the foundation on which moral harassment at work rests and contributes significantly to work place mental health. Methodology: We conducted a quantitative, cross sectional descriptive study between April 1 and June 30, 2018 at the Grands Moulins de Dakar “GMD”. We used a questionnaire containing the socio-demographic data to which we added the Masson Meret and Steiner questionnaire called, “Ambiance in professional environment”. We used the Epi info software for data entry and analysis. Results: Sample population was 100 subjects with average age of 42.18 years ± 7.6, a male predominance of 91% and average length of service in the company was 15.27 years ± 10.1. Hostile behavior was more frequently reported than stress, with 49% and 28% respectively. Among the hostile behavior we found criticism in the professional field in 35% of the cases and rumors mongering was observed in 25% of the cases. The most reported stress symptom was general fatigue (45%), hostile behavior was more common in males (40 - 49 years of age and those with more than 10 dependents). Of the officers who felt generally unwell, 78.9% were victims of hostile behavior. Conclusion: Hostile behavior forms the basis of moral harassment at work and their devious nature makes them difficult to detect, this contrasts with its harmful consequences on the health of the staff. Potentially harmful workplace stress has become more frequently encountered in the contemporary workplace and has constituted an occupational hazard. The most common symptoms reported are feeling unwell and general fatigue.

关键词： Bulling Moral Harassment Psychosocial Violence Stress Senegal