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Temperature Uniformity,Correlations and the Flow Field in Swirling Impinging Jets

Journal of Thermal Science 2023年第2期32卷 662-679页

作者： Zahir U.ahmed Yasir m.AL-ABDELI Department of mechanical Engineering Khulna University of Engineering&TechnologyKhulna 9203Bangladesh School of Engineering Edith Cowan UniversityJoondalupWA 6027Australia

Infrared thermography,velocity and impingement pressure measurements alongside numerical modelling are used in this study to resolve(heated)surface temperature distributions of turbulent swirling impinging jets for two Reynolds numbers(Re=11600 and 24600).Whilst building upon earlier discoveries for this same geometry,this paper provides three new contributions:(1)identifying the role of impingement distance(H/D)as a deciding factor in the trade-off between more efficient heat transfer(at high swirl numbers)and achieving better substrate temperature uniformity(lower gradients),(2)developing correlations to predict Nusselt number for swirling and non-swirling cooling jets,and(3)predicting the underlying mixing field in these jets and its interplay with the thermal distributions *** indicate substrate temperature uniformity varies based on H/D and swirl intensity(S)with a significant level of thermal non-uniformity occurring in near-field impingement(H/D=1)at stronger swirl(S=0.59 and 0.74).Four correlations describing the effects of S,Re,and H on the average heat transfer and stagnation heat transfer are developed and yield accuracies of 8%and 12%,*** recirculation near the impingement surface is predicted at H/D=1 for stronger swirl jets which disappears at other substrate *** peak wall shear stress reduces and the flow impingement becomes radially wider at higher H/D and *** turbulence or eddy viscosity regions for non-swirling jets(S=0)are predicted in the shear layer and entrainment regions at H/D=1,but such turbulence is confined to the impingement and wall jet regions for strongly swirling flows.

关键词： Temperature uniformity Nusselt number IR imaging CTA RANS

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Some aspects affecting the response of RC compartment structures subjected to internal blast loads

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Earthquake Engineering and Engineering Vibration 2022年第1期21卷 135-148页

作者： Osman m.O.Ramadan m.Galal El Sherbiny ahmed m.Khalil Faculty of Engineering Cairo UniversityCairo 12411Egypt Higher Technological Institute(HTI)at 10th of Ramadan City Sharqia 13658Egypt Structural Engineering and Construction management Department Faculty of Engineering&TechnologyFutureUniversity in Egypt-FUECairo 16383Egypt

Protective compartments are typically used to protect some specific structures from internal explosions,such as industrial buildings that contain devices that may explode in certain *** research investigates how the response of reinforced concrete(RC)compartment structures subjected to internal blast loads are affected by the following aspects:introduction of material nonlinearity in the analysis,reinforcement ratio,and aspect ratio of the *** achieve this goal,a calibrated and sophisticated FE numerical model is introduced,and a parametric study for the intended aspects is carried out.A discussion of the results and conclusions are offered,which show the role of each aspect in the dynamic performance of the compartment *** main conclusions are as follows:introduction of material nonlinearity in this type of analysis and for these structures is very important and significant in obtaining accurate outputs that are similar to actual behavior;the reinforcement ratio has a significant effect on the response and its effect varies depending on the thickness of the compartment;in general,increasing the reinforcement ratio enhances the behavior and reduces the stresses in the compartment;and the aspect ratio of the compartment does not show a clear pattern on the response of such structures under internal blast loads.

关键词： blast loads protective structures nonlinear analysis explicit dynamic analysis

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An Adaptive Real-Time Third Order Sliding mode Control for NonlinearSystems

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Computers, materials & Continua 2022年第9期72卷 5629-5641页

作者： ahmed m.Elmogy Amany Sarhan Wael m.Elawady Computer Engineering Department Prince Sattam Bin Abdelaziz UniversityAlkharj24567KSA Department of Computers and Control Engineering Tanta UniversityTanta13457Egypt

As most real world systems are significantly nonlinear in nature,developing robust controllers have attracted many researchers for *** controllers are the controllers that are able to cope with the inherent uncertainties of the nonlinear *** control methods have been developed for this *** mode control(SmC)is one of the most commonly used methods in developing robust *** paper presents a higher order SmC(HOSmC)approach to mitigate the chattering problem of the traditional SmC *** developed approach combines a third order SmC with an adaptive PID(proportional,integral,derivative)sliding surface to overcome the drawbacks of using PID controller ***,the presented approach is capable of adaptively tuning the controller parameters online to best fit the real time *** Lyapunov theory is used to validate the stability of the presented approach and its feasibility is tested through a comparison with other conventional SmC approaches.

关键词： SmC uncertain nonlinear systems PID lyapunov theory

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Implications of Onshore Development on Global Software Engineering

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Computers, materials & Continua 2023年第2期74卷 3029-3044页

作者： Abdulrahman m.Qahtani ahmed S.Ghiduk College of Computers and Information Technology Taif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of mathematics and Computer Science Faculty of ScienceBeni-Suef UniversityBeni-Suef62521Egypt

Recently software industry has paid significant attention to customizing software products across distributed *** the requirements of multiple clients across distributed borders is a crucial challenge for the software customization *** decision-making and local development at the client site are considered methods for reducing difficulties in communicating the requirements of multiple clients across distributed *** paper introduces a new model called the onshore development model(ODm)for accomplishing the customization requests in the distributed development process of *** model presents a scenario for enhancing the onsite development of specific requirements to reduce delays andmisunderstandings between the clients and the team *** model depends on moving the development process to the client’s *** empirical studies were conducted to evaluate the proposed model to measure its productivity,time performance,and cost *** proposed model has been compared with two other models:the basic model(Bm),which allocates the decision-making process and the development process for teams at the vendor’s location,and the local decision-making model(LDec),which assigns the decision-making process for team at the client’s *** results of the empirical studies showed significant outperforming of the proposed model over the basic model and local decision-making model in productivity,time performance,and cost *** productivity of the proposed model improved by 39%and 10%more than the basic model and the local decision-making model,*** addition,the time performance of the proposed model became faster by 49%and 20.8%than the basic model and the local decision-making model,***,it reduced the total cost of the development process by 31%in terms of the salaries of all persons involved in requirements collecting,decision-making,and development.

关键词： Distributed development local development software customization

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Optimal FOPID Controllers for LFC Including Renewables by Bald Eagle Optimizer

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Computers, materials & Continua 2022年第12期73卷 5525-5541页

作者： ahmed m.Agwa mohamed Abdeen Shaaban m.Shaaban Department of Electrical Engineering College of EngineeringNorthern Border UniversityArar1321Saudi Arabia Electrical Engineering Department Faculty of EngineeringAl-Azhar UniversityCairo11651Egypt Department of Engineering Basic Science Faculty of EngineeringMenoufia UniversityShebin El-Kom32511Egypt

In this study,a bald eagle optimizer(BEO)is used to get optimal parameters of the fractional-order proportional-integral-derivative(FOPID)controller for load frequency control(LFC).SinceBEOtakes only a very short time in finding the optimal solution,it is selected for designing the FOPID controller that improves the system stability and maintains the frequency within a satisfactory range at different *** and demonstrations are carried out using *** performance of the BEOFOPID controller is evaluated using a two-zone interlinked power system at different loads and under uncertainty of wind and solar *** robustness of the BEO-FOPID controller is examined by testing its performance under varying system time *** results obtained by the BEOFOPID controller are compared with those obtained by BEO-PID and PID controllers based on recent metaheuristics optimization algorithms,namely the sine-cosine approach,Jaya approach,grey wolf optimizer,genetic algorithm,bacteria foraging optimizer,and equilibrium optimization *** results confirm that the BEO-FOPID controller obtains the finest result,with the lowest frequency *** results also confirm that the BEOFOPID controller is stable and robust at different loads,under varying system time constants,and under uncertainty of wind and solar energies.

关键词： Fractional order PID control load frequency control renewable energy bald eagle optimizer

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CTAB-assisted fabrication of hierarchical flower-like magnesium oxide adsorbent for enhanced removal performance towards phosphate

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Journal of magnesium and Alloys 2023年第9期11卷 3231-3240页

作者： Saeed ahmed State Key Laboratory of Chemical Resource Engineering College of ChemistryBeijing University of Chemical TechnologyBeijing 100029China Department of Chemistry The University of LahoreLahore 54590Pakistan Department of Chemistry University of ChakwalPakistan

In this work, a series of hierarchical flower-like magnesium oxide(mgO) adsorbents were successfully fabricated in a cetyltrimethylammonium bromide(CTAB) assisted solvothermal route using hexamethylenetetramine(HmTA) as a precipitating agent. Effects of CTAB feeding amount on the structure, morphology, pore structure, and corresponding adsorption behavior were investigated. The hierarchical gardenias flower-like mgO demonstrated a surface area of 336.54 m^(2)·g^(-1) at a minimum ratio of the CTAB/mg^(2+)was 0.02 in the reaction system. The hierarchical mgO phosphate removal capacity was 348.32 mg·g^(-1), which followed the pseudo-second-order and Freundlich isotherm model obtained from the large surface area and appropriate pore size. The value of n also suggests the feasible nature of phosphate adsorption under the examined conditions. Indeed, this CTAB assisted solvothermal method can provide a new understanding to tune the desired properties of a material by merely adjusting the reaction parameters of mgO.

关键词： Adsorption CTAB-assisted magnesium oxide Phosphate removal Solvothermal

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Neuro-Based Higher Order Sliding mode Control for Perturbed Nonlinear Systems

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Intelligent Automation & Soft Computing 2023年第4期36卷 385-400页

作者： ahmed m.Elmogy Wael m.Elawady Computer Engineering Department Prince Sattam Bin Abdelaziz UniversityAlkharj24567KSA Department of Computers and Control Engineering Tanta UniversityTanta13457Egypt

One of the great concerns when tackling nonlinear systems is how to design a robust controller that is able to deal with *** researchers have been working on developing such type of *** of the most efﬁ-cient techniques employed to develop such controllers is sliding mode control(SmC).However,the low order SmC suffers from chattering problem which harm the actuators of the control system and thus unsuitable to be used in many practical *** this paper,the drawbacks of low order traditional sliding mode control(FOTSmC)are resolved by presenting a novel adaptive radial basis function neural network–based generalized rth order sliding mode control strategy for nth order uncertain nonlinear *** proposed solution adopts neural networks for their excellent capability in function approximation and thus used to approximate the nonlinearities and uncertainties for systems under *** approximation errors are completely considered in the developed *** proposed approach can be used with any order of sliding mode and thus can be generally used with various types of *** global sta-bility of the proposed control approach is proved through Lyapunov stability *** proposed approach is validated and assessed through simulations on the nonlinear inverted pendulum system with severe modeling *** simulations results show that the proposed approach provide superior perfor-mance compared with other approaches in the literature.

关键词： SmC nonlinear systems PID Lyapunov stability radial basis function neural networks

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Genetic Based Approach for Optimal Power and Channel Allocation to Enhance D2D Underlaied Cellular Network Capacity in 5G

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Computers, materials & Continua 2022年第8期72卷 3751-3762页

作者： ahmed.A.Rosas mona Shokair m.I.Dessouky Department of Electronics and Electrical Communication Engineering Faculty of Electronic EngineeringMenoufia UniversityMenouf32952Egypt

With the obvious throughput shortage in traditional cellular radio networks,Device-to-Device(D2D)communications has gained a lot of attention to improve the utilization,capacity and channel performance of nextgeneration *** this paper,we study a joint consideration of power and channel allocation based on genetic algorithm as a promising direction to expand the overall network capacity for D2D underlaied cellular *** genetic based algorithm targets allocating more suitable channels to D2D users and finding the optimal transmit powers for all D2D links and cellular users efficiently,aiming to maximize the overall system throughput of D2D underlaied cellular network with minimum interference level,while satisfying the required quality of service QoS of each *** simulation results show that our proposed approach has an advantage in terms of maximizing the overall system utilization than fixed,random,BAT algorithm(BA)and Particle Swarm Optimization(PSO)based power allocation schemes.

关键词： 5G D2D communication spectrum allocation power allocation genetic algorithm optimization BAT-optimization particle swarm optimization

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ATS:A Novel Time-Sharing CPU Scheduling Algorithm Based on Features Similarities

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Computers, materials & Continua 2022年第3期70卷 6271-6288页

作者： Samih m.mostafa Sahar ahmed Idris manjit Kaur Faculty of Computers and Information South Valley UniversityQena83523Egypt College of Industrial Engineering King Khalid UniversityAbhaSaudi Arabia School of Engineering and Applied Sciences Bennett UniversityGreater NoidaIndia

minimizing time cost in time-shared operating systems is considered basic and essential task,and it is the most significant goal for the researchers who interested in CPU scheduling *** time,turnaround time,and number of context switches are themost time cost criteria used to compare between CPU scheduling *** scheduling algorithms are divided into non-preemptive and ***(RR)algorithm is the most famous as it is the basis for all the algorithms used in *** this paper,the authors proposed a novel CPU scheduling algorithm based on *** proposed algorithm is called Adjustable Time Slice(ATS).It reduces the time cost by taking the advantage of the low overhead of RR *** addition,ATS favors short processes allowing them to run longer time than given to long *** specific characteristics of each process are;its CPU execution time,weight,time slice,and number of context *** clusters the processes in groups depending on these *** traditionalRRassigns fixed time slice for each *** the other hand,dynamic variants of RR assign time slice for each process differs from other *** essential difference between ATS and the other methods is that it gives a set of processes a specific time based on their similarities within the same *** authors compared between ATS with five popular scheduling algorithms on nine datasets of *** datasets used in the comparison vary in their *** evaluation was measured in term of time cost and the experiments showed that the proposed algorithm reduces the time cost.

关键词： Clustering CPU scheduling round robin average turnaround time average waiting time

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Impact Assessment and mitigation Techniques for High Penetration Levels of Renewable Energy Sources in Distribution Networks:Voltage-control Perspective

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Journal of modern Power Systems and Clean Energy 2022年第2期10卷 450-458页

作者： ahmed S.A.Awad Dave Turcotte Tarek H.m.El-Fouly Natural Resources Canada Can-metENERGYVarennesCanadaon leave from the Electrical Power and Machines DepartmentFaculty of EngineeringAin Shams UniversityCairo 11566Egyp Natural Resources Canada CanmetENERGYVarennesCanada Advanced Power and Energy Center Khalifa UniversityAbu DhabiUnited Arab Emirates

The integration of renewable distributed generation(RDG)into distribution networks is promising and increasing ***,high penetration levels of distributed generation(DG)are often limited as they may have an adverse effect on the operation of distribution *** of the operation challenges is the interaction between DG and voltage-control equipment,e.g.,an under-load tap changer(ULTC),which is basically designed to compensate for voltage changes caused by slow load *** integration of variable DGs leads to rapid voltage fluctuations,which can negatively affect the tap operation of *** paper investigates the impact of high penetration levels of RDG on the tap operation of ULTC in distribution networks through *** mitigation techniques that can alleviate this impact are also *** these techniques,constant power-factor mode is regarded as the best trade-off between the simplicity and effectiveness of minimizing the number of tap *** are performed on a Canadian benchmark rural distribution feeder using OpenDSS software.

关键词： Renewable energy distributed generation(DG) voltage regulator load tap changer distribution network.

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