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Solar thermochemical reactions Ⅱ:Synthesis of 2-aminothiophenes via Gewald reaction induced by solar thermal energy

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Chinese Chemical Letters 2008年第7期19卷 788-790页

作者： ramadan ahmed Mekheimer Mohamed Abdallah Ameen Kamal Usef Sadek Chemistry Department Faculty of ScienceEl-Minia UniversityEl-Minia 61519Egypt

Green conditions have been developed for the synthesis of substituted 2-aminothiophenes employing multicomponent reactions of a ketone with active methylene nitrile and elemental sulphur induced by free solar thermal ... 详细信息

关键词： 2-Aminothiophenes Gewald reaction Solar thermal energy

ANFIS-based Sensor Fusion System of Sit-to-stand for Elderly People Assistive Device Protocols

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International Journal of Automation and computing 2013年第5期10卷 405-413页

作者： Omar Salah ahmed A.ramadan Salvatore Sessa ahmed Abo Ismail Makasatsu Fujie Atsuo Takanishi Egypt-Japan University of Science and Technology New Borg-El-Arab City Faculty of Engineering Tanta University Faculty of Science and Engineering Waseda University

This paper describes the analysis and design of an assistive device for elderly people under development at the EgyptJapan University of Science and Technology（E-JUST） named E-JUST assistive device（EJAD）.Several experiments were carried out using a motion capture system（VICON） and inertial sensors to identify the human posture during the sit-to-stand *** EJAD uses only two inertial measurement units（IMUs） fused through an adaptive neuro-fuzzy inference systems（ANFIS） algorithm to imitate the real motion of the *** EJAD consists of two main parts,a robot arm and an active *** robot arm is a 2-degree-of-freedom（2-DOF） planar *** addition,a back support with a passive joint is used to support the patient s *** IMUs on the leg and trunk of the patient are used to compensate for and adapt to the EJAD system motion depending on the obtained patient *** ANFIS algorithm is used to train the fuzzy system that converts the IMUs signals to the right posture of the patient.A control scheme is proposed to control the system motion based on practical measurements taken from the experiments.A computer simulation showed a relatively good performance of the EJAD in assisting the patient.

关键词： Adaptive neuro-fuzzy inference systems(ANFIS) sensor fusion assistive technologies sit-to-stand motion analysis inertial measurement units

Patterns of liver profile disturbance in patients with COVID-19

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World Journal of Clinical Cases 2022年第7期10卷 2063-2071页

作者： Hend Ibrahim Shousha ahmed ramadan Rania Lithy Mohamed El-Kassas Department of Endemic Medicine Faculty of MedicineCairo UniversityCairo 12556Egypt Department of Endemic Medicine Faculty of MedicineHelwan UniversityCairo 11795Egypt

Fever and cough are the most common clinical symptoms of coronavirus disease 2019(COVID-19),but complications(such as pneumonia,respiratory distress syndrome,and multiorgan failure)can occur in people with additional ***-19 may be a new cause of liver disease,as liver profile disturbance is one of the most common findings among *** molecular mechanism underlying this phenomenon,however,is still *** this paper,we review the most current research on the patterns of change in liver profile among patients with COVID-19,the possible explanation for these findings,and the relation to pre-existing liver disease in these patients.

关键词： Liver functions COVID-19 Liver profile Alanine transaminase aspartate transaminase Bilirubin

Effect of Tempcore Processing on Mitigating Problems of Tramp Elements in Low C Steel Produced from Recycled Material

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Journal of Iron and Steel Research International 2015年第7期22卷 582-589页

作者： ahmed ramadan A.Y.SHASH I.S.EL-MAHALLAWI D.SENK Taha MATTAR Quality Department Faculty of Engineering Cairo University Institute of Ferrous Metallurgy RWTH-Aachen University Central Metallurgical Research and Development Institute

The effect of tramp elements in the steel was intensively studied. It was found that the solubility of tramp elements decreased as the temperature decreased under normal cooling conditions. The tramp elements （Cu, Pb, and Sn） diffused toward the grain boundaries, and intermetallic compounds or rich phases which have low melting points were formed, causing reduction in ductility and failure during the bending test. Rebars with Cu content which were left to air cooling after the last step showed drop in elongation, up to 32 %. On contrast, the samples with high per- centage of tramp elements （Cu, Pb, and Sn） in the billet, which were rolled and subjected to Tempcore process, did not show drop in elongation or failure in bending test （especially for rebar with diameter less than 32 mm）; however, copper must be less than 0.35 mass% to prevent the precipitation of Cu-rich zones of critical size in 32 mm. When quench- ing was applied, the tramp elements remained in the interstitial supersaturated solid solution positions inside the grains and would not have the chance to diffuse and form precipitates, hindering the copper precipitates from reac- hing the critical size necessary for impairing the properties. This would hinder the occurrence of the harmful effect of the tramp elements on the elongation or the hot shortness after rolling.

关键词： recycled steel hot shortness crack susceptibility Tempcore process tramp element residual melt

Improved Control in Single Phase Inverter Grid-Tied PV System Using Modified PQ Theory

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Intelligent Automation & Soft Computing 2023年第8期37卷 2441-2457页

作者： Nur Fairuz Mohamed Yusof Dahaman Ishak Muhammad Ammirrul Atiqi Mohd Zainuri Muhammad Najwan Hamidi Zuhair Muhammed Alaas Mohamed Mostafa ramadan ahmed Faculty of Electrical Engineering&Technology Universiti Malaysia Perlis02600ArauMalaysia School of Electrical&Electronic Engineering Universiti Sains Malaysia14300Nibong TebalMalaysia Department of Electrical Electronic and Systems EngineeringFaculty of Engineering and Built EnvironmentUniversiti Kebangsaan MalaysiaSelangor43600Malaysia School of Engineering Jazan UniversityJazanSaudi Arabia Faculty of Technology and Education Helwan UniversityCairoEgypt

Grid-connected reactive-load compensation and harmonic control are becoming a central topic as photovoltaic(PV)grid-connected systems *** research aims to produce a high-performance inverter with a fast dynamic response for accurate reference tracking and a low total har-monic distortion(THD)even under nonlinear load applications by improving its control *** proposed system is expected to operate in both stand-alone mode and grid-connected *** stand-alone mode,the proposed controller supplies power to critical loads,alternatively during grid-connected mode provide excess energy to the utility.A modified variable step incremental conductance(VS-InCond)algorithm is designed to extract maximum power from *** the proposed inverter controller is achieved by using a modified PQ theory with double-band hysteresis current controller(PQ-DBHCC)to produce a reference current based on a decomposition of a single-phase load *** nonlinear rectifier loads often create significant distortion in the output voltage of single-phase inverters,due to excessive current harmonics in the ***,the proposed method generates a close-loop reference current for the switching scheme,hence,minimizing the inverter voltage distortion caused by the excessive grid current *** simulation findings suggest the proposed control technique can effectively yield more than 97%of power conversion efficiency while suppressing the grid current THD by less than 2%and maintaining the unity power factor at the grid *** efficacy of the proposed controller is simulated using MATLAB/Simulink.

关键词： Hysteresis current controller incremental conductance nonlinear load PQ theory single-phase inverter

Laser Surface Hardening of Tool Steels—Experimental and Numerical Analysis

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Journal of Surface Engineered Materials and Advanced Technology 2013年第2期3卷 146-153页

作者： Abdel-Monem El-Batahgy ramadan ahmed ramadan Abdel-Rahman Moussa Manufacturing Technology Department Central Metallurgical R & D Institute Cairo Egypt Mechanical Engineering Department Faculty of Engineering Helwan University Helwan Egypt. Spare Parts Sector Egyptian Iron and Steel Company Helwan Egypt

This research work is focused on both experimental and numerical analysis of laser surface hardening of AISI M2 high speed tool steel. Experimental analysis aims at clarifying effect of different laser processing parameters on properties and performance of laser surface treated specimens. Numerical analysis is concerned with analytical approaches that provide efficient tools for estimation of surface temperature, surface hardness and hardened depth as a function of laser surface hardening parameters. Results indicated that optimization of laser processing parameters including laser power, laser spot size and processing speed combination is of considerable importance for achieving maximum surface hardness and deepest hardened zone. In this concern, higher laser power, larger spot size and lower processing speed are more efficient. Hardened zone with 1.25 mm depth and 996 HV surface hardness was obtained using 1800 W laser power, 4 mm laser spot size and 0.5 m/min laser processing speed. The obtained maximum hardness of laser surface treated specimen is 23% higher than that of conventionally heat treated specimen. This in turn has resulted in 30% increase in wear resistance of laser surface treated specimen. Numerical analysis has been carried out for calculation of temperature gradient and cooling rate based on Ashby and Easterling equations. Then, surface hardness and hardened depth have been numerically estimated based on available Design-Expert software. Numerical results indicated that cooling rate of laser surface treated specimen is high enough to be beyond the nose of the CCT diagram of the used steel that in turn resulted in a hard/martensitic structure. Numerically estimated values of surface temperature, surface hardness and hardened depth as a function of laser processing parameters are in a good agreement with experimental results. Laser processing charts indicating expected values of surface temperature, surface hardness and hardened depth as a function

关键词： High Speed Tool Steels Laser Surface Hardening Ashby and Easterling Heat Transfer Equations Design Expert Software Laser Processing Charts

ANFIS Based Controller for Double Inverted Pendulum System with Payload

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ANFIS Based Controller for Double Inverted Pendulum System w...

Tethering of Homo and Block Glycopolymer Chains onto Montmorillonite Surface by Atom Transfer Radical Polymerization

2011 IEEE International Conference on Intelligent Computing and Intelligent Systems(ICIS 2011)

作者： Omar Mehrez ahmed ramadan ahmed Abo-Ismail Mechatronics and Robotics Engineering Department School of Innovative Design Engineering Egypt-Japan University of Science and TechnologyE-JUSTNew Borg El-Arab cityAlexandriaEgypt

The swing up and stabilization of inverted pendulum systems represents a challenge task for *** more the number of links,the more difficult is to control the ***,we propose a double inverted pendulum system with a payload of significant mass attached to the second *** mass addition is not only to increase the complexity of the control problem,but also has significant effect on the development of applications that are simply modeled with inverted pendulum systems such as humanoid robots and mobile *** ANFIS controller based on the training from an optimal LQR controller is introduced to stabilize the system around the equilibrium *** rule numbers explosion of the ANFIS controller is solved by combining the system variables into only two states;the error and error *** performance of the ANFIS controller is compared with the optimal one,which shows better performance,covering wider range,and much more robustness against disturbances.

关键词： fuzzy control double inverted pendulum with payload fuzzy rules number problem

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Open Journal of Organic Polymer Materials 2012年第4期2卷 80-88页

作者： Amal Amin Heba Kandil ahmed ramadan Mohamed Nader Ismail Chemistry Department Faculty of Science Helwan University Cairo Egypt Polymers & Pigments Department National Research Center Giza Egypt

Well-defined homo glycopolymer/montmorillonite (MMT) nanocomposite (gly1) was prepared successfully by the “grafting from” technique from the modified surface of MMT via surface initiated atom transfer radical polymerization (SI-ATRP) of 3-O-methacryloyl-1,2:5,6-di-O-isopropylidene-α-D-glucofuranose (gly) in the presence of Cu(I)Br/ bi- pyridyl at 90?C in xylene. Well-defined diblock copolymers (gly2, gly3, gly4 and gly5) were also synthesized via the same technique by using comonomers of methylmethacrylate (MMA) or styrene (St) with glycomonomer (gly) using the same catalytic system. The formed nanocomposites showed both intercalated and exfoliated structures, as judged by XRD and TEM measurements. Further analyses were performed on such nanocomposites to confirm their formation such as TGA and DSC. The structures of the attached polymers to MMT were characterized by 1H NMR.

关键词： Glycopolymers Polymer/Layered Silicates Nanocomposites SI-ATRP Montmorillonite

Generalized Power Akshaya Distribution and Its Applications

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Open Journal of Modelling and Simulation 2021年第4期9卷 323-338页

作者： ahmed T. ramadan Ahlam H. Tolba Beih S. El-Desouky Department of Basic Sciences High Raya Institute New Damietta Egypt Department of Mathematics Faculty of Science Mansoura University Mansoura Egypt

In this paper, a new two-parameter distribution called generalized power Akshaya distribution extended from Akshaya distribution is introduced. This distribution is proposed to model lifetime data. Statistical properties like density, hazard, survival and moments are derived. Two parameters estimation is introduced using maximum likelihood and Bayesian techniques. Finally, an application of real data and a simulation study are introduced to illustrate the usefulness of the proposed distribution.

关键词： Akshaya Distribution Generalized Distributions Moments Estimation