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Ureteroscopy with Holmium: YAG Laser—A Initial Study in the Urology Department of the Pr Bocar Sidy Sall University Hospital of Kati

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Open Journal of Urology 2024年第4期14卷 207-216页

作者： Amadou Kassogue Idrissa Sissoko Daouda Sangare Moussa Salifou Diallo hamed sylla Mahamadou Traore Boureima Coulibaly Salia Coulibaly Modibo Diakite Modibo Togola Fadima Tall Ilias Guindo Ben Naoum Kamel Mamadou Lamine Diakite Urology Department University Hospital of Pr Bocar Sidy Sall Kati Mali Radiology Department University Hospital of Pr Bocar Sidy Sall Kati Mali Anesthesy and Reanimation Department University Hospital of Pr Bocar Sidy Sall Kati Mali Urology Department University Hospital Nimes France Urology Department University Hospital of Point G Bamako Mali

Introduction: Ureteroscopy is a minimally invasive endoscopic surgery which provides access to the ureter, pyelon and calyceal cavities via the urethra and the bladder. Laser ureteroscopy uses the laser as an energy source to treat the stone and eliminate it naturally. Minimally invasive endoscopic methods are struggling to become popular in sub-Saharan African countries, especially for the upper urinary tract. The objective of our work was to report the results of our first laser ureteroscopy experience in the department. Materials and Methods: This was a prospective and descriptive study running from December 1, 2023 to February 19, 2024. Included in our study was any case of upper urinary tract stone operated by Laser ureteroscopy. The characteristics of the lithiasis were determined by CT scan. Sterilization of urine was verified by carrying out a cytobacteriological examination of urine. Ureteral lithiasis was approached by semi-rigid ureteroscopy. Renal lithiasis was immediately addressed by flexible ureteroscopy. Ureteroscopy was coupled with a Holmium YAG laser. A double J ureteral catheter was placed after the operation. A 230 µm laser fiber was used in each case with a generator with a power of 35 watts (Storz Calculase III type). An access sheath was used in all cases of flexible ureteroscopy. The parameters studied were: sociodemographic characteristics, lithiasis (site, size, number, density, topography), type of anesthesia, duration of laser use, duration of intervention, postoperative outcomes. Data entry and analysis were carried out using the software (Word 2016 and SPSS). Result: We collected 30 cases of laser ureteroscopy. The average age was 37 years with extremes of 9 and 79 years. The male gender was more represented. The most common age group was 24-39 years old. Renal colic was the most frequent reason for admission, 12 patients (40%). On physical examination, lumbar tenderness was present in 47% (14 patients). ECBU was positive in 4 patients

关键词： Ureteroscopy Semi-Rigid Flexible Holmium YAG Laser

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Ureteroscopy with Holmium: YAG Laser—A Initial Study in the Urology Department of the Pr Bocar Sidy Sall University Hospital of Kati

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Open Journal of Urology（泌尿学期刊） 2024年第4期 207页

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Surface metal-matrix composites based on AZ91 magnesium alloy via friction stir processing:A review

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International Journal of Minerals,Metallurgy and Materials 2023年第7期30卷 1278-1296页

作者： hamed Mirzadeh School of Metallurgy and Materials Engineering College of EngineeringUniversity of TehranTehranIran

This monograph presents an overview of friction stir processing(FSP)of surface metal-matrix composites(MMCs)using the AZ91 magnesium *** reported results in relation to various reinforcing particles,including silicon carbide(SiC),alumina(Al_(2)O_(3)),quartz(SiO_(2)),boron carbide(B_(4)C),titanium carbide(TiC),carbon fiber,hydroxyapatite(HA),in-situ formed phases,and hybrid reinforcements are ***91 composite fabricating methods based on FSP are explained,including groove filling(grooving),drilled hole filling,sandwich method,stir casting followed by FSP,and formation of in-situ *** effects of introducing second-phase particles and FSP process parameters(e.g.,tool rotation rate,traverse speed,and the number of passes)on the microstructural modification,grain refinement,homogeneity in the distribution of particles,inhibition of grain growth,mechanical properties,strength–ductility trade-off,wear/tribological behavior,and corrosion resistance are ***,useful suggestions for future work are proposed,including focusing on the superplasticity and superplastic forming,metal additive manufacturing processes based on friction stir engineering(such as additive friction stir deposition),direct FSP,stationary shoulder FSP,correlation of the dynamic recrystallization(DRX)grain size with the Zener–Hollomon parameter similar to hot deformation studies,process parameters(such as the particle volume fraction and external cooling),and common reinforcing phases such as zirconia(ZrO_(2))and carbon nanotubes(CNTs).

关键词： surface composites magnesium alloys friction stir processing severe plastic deformation thermomechanical processing

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Minimum Reservoir Water Level in Hydropower Dams

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Chinese Journal of Mechanical Engineering 2017年第4期30卷 1017-1024页

作者： hamed Sarkardeh Department of Civil Engineering Hakim Sabzevari UniversitySabzevarIran

Vortex formation over the intakes is an unde- sirable phenomenon within the water withdrawal process from a dam reservoir. Calculating the minimum operating water level in power intakes by empirical equations is not a safe way and sometimes contains some errors. Therefore, current method to calculate the critical submergence of a power intake is construction of a scaled physical model in parallel with numerical model. In this research some pro- posed empirical relations for prediction of submergence depth in power intakes were validated with experimental data of different physical and numerical models of power intakes. Results showed that, equations which involved the geometry of intake have better correspondence with the experimental and numerical data.

关键词： Power intake. Vortex Critical submergence Physical and numerical models Empirical equations

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Microstructural evolution and mechanical properties of friction stir-welded C71000 copper–nickel alloy and 304 austenitic stainless steel

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International Journal of Minerals,Metallurgy and Materials 2018年第11期25卷 1294-1303页

作者： hamed Jamshidi Aval Department of Materials and Industrial Engineering Babol Noshirvani University of Technology

Dissimilar joints comprised of copper–nickel and steel alloys are a challenge for manufacturers in modern industries, as these metals are not thermomechanically or chemically well matched. The present study investigated the effects of tool rotational speed and linear speed on the microstructure and mechanical properties of friction stir-welded C71000 copper–nickel and 340 stainless steel alloys using a tungsten carbide tool with a cylindrical pin. The results indicated that a rotational-to-linear speed ratio of 12.5 r/mm did not cause any macro defects, whereas some tunneling defects and longitudinal cracks were found at other ratios that were lower and higher. Furthermore, chromium carbide was formed on the grain boundaries of the 304 stainless steel near the shoulder zone and inside the joint zone, directing carbon and chromium penetration toward the grain boundaries. Tensile strength and elongation percentages were 84% and 65% of the corresponding values in the copper–nickel base metal, respectively.

关键词： dissimilar friction stir welding copper–nickel alloy austenitic stainless steel microstructure mechanical properties

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Optimal State Estimation and Fault Diagnosis for a Class of Nonlinear Systems

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IEEE/CAA Journal of Automatica Sinica 2020年第2期7卷 517-526页

作者： hamed Kazemi Alireza Yazdizadeh Department of Electrical Engineering Shahid Beheshti UniversityTehran ***Iran

This study proposes a scheme for state estimation and,consequently,fault diagnosis in nonlinear ***,an optimal nonlinear observer is designed for nonlinear systems subject to an actuator or plant *** utilizing Lyapunov's direct method,the observer is proved to be optimal with respect to a performance function,including the magnitude of the observer gain and the convergence *** observer gain is obtained by using approximation of Hamilton-Jacobi-Bellman(HJB)*** approximation is determined via an online trained neural network(NN).Next a class of affine nonlinear systems is considered which is subject to unknown disturbances in addition to fault *** this case,for each fault the original system is transformed to a new form in which the proposed optimal observer can be applied for state estimation and fault detection and isolation(FDI).Simulation results of a singlelink flexible joint robot(SLFJR)electric drive system show the effectiveness of the proposed methodology.

关键词： Differential geometry fault detection and isolation(FDI) fault diagnosis neural network(NN) nonlinear observer and filter design optimal state estimation

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Charge structure factors of doped armchair nanotubes in the presence of electron-phonon interaction

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Chinese Physics B 2020年第9期29卷 415-422页

作者： hamed Rezania Farshad Azizi Department of Physics Razi UniversityKermanshahIran

We present the behaviors of both dynamical and static charge susceptibilities of doped armchair nanotubes using the Green function approach in the context of Holstein-model ***,the effects of magnetization and gap parameter on the the plasmon modes of armchair nanotube are investigated via calculating correlation function of charge density *** phase approximation has been implemented to find the interacting dynamical charge *** electrons in this systems interacts with each other by mediation of dispersionless Holstein *** results show that the increase of gap parameter leads to decreasing intensity of charge collective *** the frequency position of the collective mode tends to higher frequencies due to the gap *** the number of collective excitation mode decreases with chemical potential in the presence of electron-phonon *** the temperature dependence of static charge structure factor of armchair nanotubes is *** effects of the gap parameter,magnetization and electron-phonon interaction on the static structure factor are addressed in details.

关键词： armchair nanotube Green's function

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Drill bit wear monitoring and failure prediction for mining automation

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International Journal of Mining Science and Technology 2023年第3期33卷 289-296页

作者： hamed Rafezi Ferri Hassani Department of Mining and Materials Engineering McGill UniversityMontreal H3A 0G4Canada

This article introduces a novel approach for tricone bit wear condition monitoring and failure prediction for surface mining applications.A successful bit health monitoring system is essential to achieve fully autonomous blasthole *** this research in-situ vibration signals were analyzed in timefrequency domain and signals trend during tricone bit life span were investigated and introduced to support the development of artificial intelligence(AI)*** addition to the signal statistical features,wavelet packet energy distribution proved to be a powerful indicator for bit wear *** artificial neural network(ANN)models were designed,trained and evaluated for bit state ***,an ANN architecture and feature vector were introduced to classify the bit condition and predict the bit failure.

关键词： Drilling vibration Condition monitoring Failure prediction Bit wear Wavelet energy Mining automation

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Drilling signals analysis for tricone bit condition monitoring

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International Journal of Mining Science and Technology 2021年第2期31卷 187-195页

作者： hamed Rafezi Ferri Hassani Department of Mining and Materials Engineering McGill UniversityMontreal H3A 0G4Canada

This paper presents a novel approach to investigate the relations between drilling signals and bit wear condition in real world full-scale mining *** research addresses the increasing demand for automation in mining to increase the efficiency,safety,and ability to work in harsh environments.A crucial issue in fully autonomous unmanned drilling is to have a system to detect the bit wear condition through the drilling signals analysis in real *** this work,based on extensive field studies,a novel qualitative method for tricone bit wear state classification is developed and *** relations between drilling vibration as well as electric motor current signals and bit wear are investigated and bit failure vibration frequencies,regardless of the geological conditions,are *** failure frequencies are experimentally investigated and analytically ***,the effect of bit design parameters on the failure frequencies is presented for the application of bit wear condition monitoring and bit failure prediction.

关键词： Drilling Tricone bit Vibration Wear Condition monitoring Failure prediction

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Convergence in Distribution for Uncertain Random Sequences with Dependent Random Variables

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Journal of Systems Science & Complexity 2021年第2期34卷 483-501页

作者： GAO Rong AHMADZADE hamed School of Economics and Management Hebei University of TechnologyTianjin 300401China Department of Mathematical Sciences University of Sistan and BaluchestanZahedanIran

Random variables and uncertain variables are respectively used to model randomness and uncertainty. While randomness and uncertainty always coexist in a same complex system. As an evolution of random variables and uncertain variables, uncertain random variable is introduced as a tool to deal with complex phenomena including randomness and uncertainty simultaneously. For uncertain random variables, a basic and important topic is to discuss the convergence of its ***, this paper focuses on studying the convergence in distribution for a sequence of uncertain random sequences with different chance distributions where random variables are not *** the result of this paper is a generalization of the existing literature. Relations among convergence theorems are studied. Furthermore, the theorems are explained by several examples.

关键词： Chance distribution convergence in distribution convergence in mean uncertain random variable

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