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Radio Frequency Quadrupole for Bunching Electron Beam: Electromagnetic Field, Particle Velocity Range, and Accuracy at 10 GHz

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Journal of Electromagnetic Analysis and Applications 2023年第1期15卷 1-11页

作者： serigne Bira gueye Department of Physics Faculty of Sciences and Techniques Cheikh Anta Diop University Dakar Senegal

The Radio Frequency Quadrupole (RFQ) accelerator invented by Kapchinskii and Tepliakov can focus, bunch, and accelerate charged-particle beams simultaneously. Typically, it operates at frequencies up to 500 MHz, for low particle velocities ( β ). The first attempt to design cylindrical RFQ for electrons in the GHz region was done using 3 GHz at Frascati in 1990. In this paper, an analytical approximation of the electromagnetic field is given, and linearized in the beam region for a rectangular Electron Radio Frequency Quadrupole (ERFQ). The differences between the proton-RFQ and the electron-RFQ are discussed. Then, it will be shown that contrary to the quadrupoles for protons or heavy-ions, the ERFQ is suited for electron velocities in the range 0.5 - 0.7 c, and possible applications are given. Finally, it is illustrated, with numerical field computations that this approach gives sufficient accuracy at 10 GHz.

关键词： Electron RF Quadrupole Buncher Linear Accelerator Linac Beam Injector

Semi-Analytical Solution of the 1D Helmholtz Equation, Obtained from Inversion of Symmetric Tridiagonal Matrix

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Journal of Electromagnetic Analysis and Applications 2014年第14期6卷 425-438页

作者： serigne Bira gueye Département de Physique Faculté des Sciences et Techniques Université Cheikh Anta Diop Dakar-Fann Sénégal

An interesting semi-analytic solution is given for the Helmholtz equation. This solution is obtained from a rigorous discussion of the regularity and the inversion of the tridiagonal symmetric matrix. Then, applications are given, showing very good accuracy. This work provides also the analytical inverse of the skew-symmetric tridiagonal matrix.

关键词： Helmholtz Equation Tridiagonal Matrix Linear Homogeneous Recurrence Relation

Expending the Paradigm: Active Surveillance for Intermediate Risk Prostate Cancer

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Open Journal of Urology 2018年第8期8卷 248-256页

作者： Mohamed Jalloh Mamadou Tieoule Traore Thierno Amadou Diallo Issa Labou Lamine Niang serigne magueye gueye Service d’Urologie Hopital General de Grand Yoff Dakar Senegal Centre Hospitalier Universitaire de Ouahigouya Ouahigouya Burkina Faso

Prostate cancer is the leading male cancer worldwide. There remains a controversy as to which patients have indolent disease and which patients present an aggressive disease needing treatment with intent to cure. Because of quality of life impairment associated with treatment by radiation or surgery, active surveillance (AS) is a valid management option to avoid or differ aggressive treatment. Traditionally, AS was reserved for men with low risk prostate cancer, however intermediate risk patients are more and more found in AS cohorts. The aim of this review is to describe the place of AS in intermediate risk patients and the perspectives offered by such a treatment modality.

关键词： Prostate Cancer Active Surveillance Intermediate Risk

The Exact Formulation of the Inverse of the Tridiagonal Matrix for Solving the 1D Poisson Equation with the Finite Difference Method

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Journal of Electromagnetic Analysis and Applications 2014年第10期6卷 303-308页

作者： serigne Bira gueye Département de Physique Faculté des Sciences et Techniques Université Cheikh Anta Diop Dakar-Fann Sénégal

A new method for solving the 1D Poisson equation is presented using the finite difference method. This method is based on the exact formulation of the inverse of the tridiagonal matrix associated with the Laplacian. This is the first time that the inverse of this remarkable matrix is determined directly and exactly. Thus, solving 1D Poisson equation becomes very accurate and extremely fast. This method is a very important tool for physics and engineering where the Poisson equation appears very often in the description of certain phenomena.

关键词： 1D Poisson Equation Finite Difference Method Tridiagonal Matrix Inversion Thomas Algorithm Gaussian Elimination Potential Problem

Exact Inversion of Pentadiagonal Matrix for Semi-Analytic Solution of 2D Poisson Equation

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Journal of Modern Physics 2022年第12期13卷 1525-1529页

作者： serigne Bira gueye Department of Physics Faculty of Sciences and Techniques Cheikh Anta Diop University Dakar-Fann Senegal

This work essentially consists in inverting in an exact, explicit, and original way the pentadiagonal Toeplitz matrix or tridiagonal block matrix resulting from the discretization of the two-dimensional Laplace operator. This method is an algorithm facilitating the resolution of a large number of problems governed by PDEs involving the Laplacian in two dimensions. It guarantees high precision and high efficiency in solving various differential equations.

关键词： Block Matrix Pentadiagonal Matrix 2D Laplacian Toeplitz Matrix Inversion

Treatment of Kidney Stones by Percutaneous Nephrolithotomy: Evaluation of the Results of the First Series of Our Experience in the Urology Department of the Idrissa Pouye General Hospital in Dakar

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Open Journal of Urology 2024年第2期14卷 104-114页

作者： Mouhamadou Moustapha Mbodji Mohamed Jalloh Medina Ndoye Abdourahmane Diallo Issa Labou Lamine Niang serigne magueye gueye Department of Urology and Andrology Hospital General Idrissa Pouye Dakar Senegal

The principle of PCNL is the extraction through a nephrostomy channel of kidney stones which are defined as the presence of crystalline concretions in the kidneys. Objectives: The objective of this work was to study the epidemiological, clinical and paraclinical aspects of patients with renal lithiasis treated by PCNL and on the other hand the different technical aspects of PCNL. Materials and Methods: This was a retrospective descriptive study, conducted in the urology department of HOGIP, covering the period from January 2015 to January 2019. We studied the demographic and clinical aspects of patients presenting renal lithiasis;we also studied the technical aspects and treatment outcomes. Statistical significance was set for α = 0.05. Results: Our series covered 82 PCNLs performed during the study period. The average age was 45.95 years, the age group [40 - 49 years] was more affected. Our study involved 44 men and 38 women, a sex ratio of 1.15. At the clinic, atypical lumbar pain was more frequent in 45.83% of cases. On URO-CT, the calculations were located more at the pyelic level (31.2%) and lower caliceal (27.2%). The size of stones measured between 15 and 20 mm in 30.52%. The stone density was between 500 and 1000 HU in 47.54% of cases. Intraoperatively, the patients were placed in lateral decubitus in 41.46% of cases. Only one access to the kidney was necessary in 87.8% of cases. The lithoclast was used in 65.85% of cases. The overall success rate (stone free) in our series was 96%. The majority of cases, 41.44%, drainage were done by natural means (totally tubeless). The average duration was 92 minutes. The complications encountered in our experience concerned 10 cases, a rate of 12.19%. Conclusion: Urinary lithiasis is more and more frequent in our regions. The development of Endo-urology offers several therapeutic options. Thus, PCNL occupies an important place in the management of kidney stones.

关键词： HOGIP Kidney Stones PCNL Stone Free Uro CT Scan

Complete Urethral Duplicity: A Rare Cause of Urinary Incontinence, New Type According to Effman’s Classification

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Open Journal of Urology 2015年第10期5卷 182-187页

作者： Kimassoum Rimtebaye Franklin Danki Sillong Arya Zarif Agah Tashkand Mignagnal Kaboro Lamine Niang serigne magueye gueye Hô pital Général de Référence Nationale (HGRN) de N’Djaména N’Djaména Tchad Hô pital Protestant de N’Gaoundéré N’Gaoundéré Cameroun Hô pital Général de Grand Yoff (HOGGY) de Dakar Dakar Senegal

Aim: To describe the clinical, anatomical, therapeutic aspects and propose a diagram of a new type of a complete urethral duplicity in classification of Effman. Material and Methods: This was a case report of a 14-year-old patient who suffered from birth of incontinence occurring while sitting with concept of preservation of normal urination. The patient was carrying two urethral meatus, one continent and the other incontinent. The two urethral meatus were easy to catheterize. The imagery was non-contributory. Resection of accessory urethra helped to make the patient continent. Informed consent was obtained from the patient’s parents for the surgical management, the anonymous use of record and photographs for scientific aims. Results: The diagnosis of urethral duplicity was retained. An explanatory approach is reported, a new scheme is proposed to improve the classification of Effman. Conclusion: The urethral duplicity is a rare urogenital abnormality whose etiology and pathophysiology are not fully understood and has not finished delivering the secret of his classification.

关键词： Urethral Duplication Epispadias Penis Kinking Notochord Sphincter

Urolithiasis: Diagnostic and Therapeutic Aspects in Urology Department of N’Djamena in Chad

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Open Journal of Urology 2015年第11期5卷 199-206页

作者： Kimassoum Rimtebaye Franklin Danki Sillong Arya Zarif Agah Tashkand Mignagnal Kaboro Lamine Niang serigne magueye gueye National General Referral Hospital of N’Djamena N’Djamena Chad Prostestant Hospital of N’Gaoundéré N’Gaoundéré Cameroon General Hospital of Grand Yoff of Dakar Dakar Senegal

Introduction: To study the clinical, paraclinical, diagnostic aspects and manage patients with urolithiasis according to the available technical facilities in urology department of N’Djamena in Chad. Urolithiasis is defined as the presence of one or more stony concretions located at any level of a segment of the urinary tract: calyx, renal pelvis, ureters, bladder and urethra. Materials and Methods: This was a descriptive type of a prospective study over a period of 4 years, from January 2008 to December 2011, involving 233 patients with urolithiasis treated in the urology department. Clinical and paraclinical examinations were the basis for the selection of patients. Informed consent of patient or their parents (for minors) was obtained for the anonymous use of records and photographs for scientific aims. Results: Urolithiasis represented 5.72% (233/4072) of all urological pathologies. Male dominance was significant with a sex ratio of 4.5/1. The age group of 0 - 10 years was the most affected with a staff of 67 (28.75%). The clinic was dominated by dysuria (44.63%), renal colic (33.91%) and hematuria (9.01%). The main anatomical location was bladder (62.23%). The management was essentially medical and surgical. We recorded 7 cases of death or post-interventional hospital mortality rate of 3%. Conclusion: Urolithiasis is a real public health problem in Chad. Due to the inadequacy of the technical platform, the management was based on the open surgery. Etiological research was impossible by lack of technical laboratory platform.

关键词： Urolithiasis Nephrectomy Cystolithotomy Calculi

Clinicobiological Profile and Management Outcomes of Male Subfertility

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Open Journal of Urology 2015年第11期5卷 207-212页

Introduction: We aim to determine the epidemiology, clinical, paraclinical and etiologic aspects and to evaluate the management of male subfertility in urology. Methodology: We conducted a retrospective descriptive study of 137 patients referred to the urology department for male sub-fertility over a period of 4 years. The analyzed variables were: clinical, paraclinical characteristics and the post therapeutic evolution. Results: The mean age was 38.41 years (range: 24 to 67 years). The semen analysis was normal in 18 patients. The semen analysis showed oligoasthenozoospermia (45.3%) and total azoospermia (24.8%). Disease history was represented by: gonorrhea (27.7%), urogenital schistosomiasis (13.2%) and hernia repair (1.2%). The hormonal test showed abnormal hormone levels including: FSH (43.8%), LH (46.7%), testosterone (36.5%), prolactin (22.6%). The incriminated etiologic factors were: varicocele (5.8 %), smoking (23.7%), alcohol intake (25.4%) and sexually transmitted diseases (42.3%). The treatment was medical in 67.9% and surgical in 32.1% of cases. After a year of follow up, 13.9% of patient’s wives were pregnant. Conclusion: Male subfertility is common in Chad. The causes are numerous and diverse. The treatment is etiology based. A better management of sexually transmitted diseases and urogenital schistosomiasis is the best way to prevent it.

关键词： Subfertility Andrology Hormone Semen Analysis Varicocele