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Particle swarm optimization algorithm for simultaneous optimal placement and sizing of shunt active power conditioner(APC)and shunt capacitor in harmonic distorted distribution system

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Journal of Central South University 2017年第9期24卷 2035-2048页

作者： mohammadi Mohammad Department of Electrical Engineering Borujerd BranchIslamic Azad UniversityBorujerdIran

Due to development of distribution systems and increase in electricity demand,the use of capacitor banks *** the other point of view,nonlinear loads generate and inject considerable harmonic currents into power *** this condition if capacitor banks are not properly selected and placed in the power system,they could amplify and propagate these harmonics and deteriorate power quality to unacceptable *** attention of disadvantages of passive filters,such as occurring resonance,nowadays the usage of this type of harmonic compensator is *** the other side,one of parallel multi-function compensating devices which are recently used in distribution system to mitigate voltage sag and harmonic distortion,performs power factor correction,and improves the overall power quality as active power conditioner(APC).Therefore,the utilization of APC in harmonic distorted system can affect and change the optimal location and size of shunt capacitor bank under harmonic distortion *** paper presents an optimization algorithm for improvement of power quality using simultaneous optimal placement and sizing of APC and shunt capacitor banks in radial distribution networks in the presence of voltage and current *** algorithm is based on particle swarm optimization(PSO).The objective function includes the cost of power losses,energy losses and those of the capacitor banks and APCs.

关键词： shunt capacitor banks active power conditioner multi-objective function particle swarm optimization (PSO) harmonic distorted distribution system

Exponential B-spline collocation method for numerical solution of the generalized regularized long wave equation

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Chinese Physics B 2015年第5期24卷 177-190页

作者： reza mohammadi Department of Mathematics University of Neyshabur

The aim of the present paper is to present a numerical algorithm for the time-dependent generalized regularized long wave equation with boundary conditions. We semi-discretize the continuous problem by means of the Crank-Nicolson finite difference method in the temporal direction and exponential B-spline collocation method in the spatial direction. The method is shown to be unconditionally stable. It is shown that the method is convergent with an order of θ（k2 ＋ h2）. Our scheme leads to a tri-diagonal nonlinear system. This new method has lower computational cost in comparison to the Sinc-collocation method. Finally, numerical examples demonstrate the stability and accuracy of this method.

关键词： solitary waves GrLW equation exponential B-spline collocation

Spatial Estimation of Saturated Hydraulic Conductivity from Terrain Attributes Using regression,Kriging,and Artificial Neural Networks

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Pedosphere 2011年第2期21卷 170-177页

作者： H.r.MOTAGHIAN J.mohammadi Department of Soil Science Agriculture CollegeShahrekord UniversityShahrekord (Iran)

Several methods,including stepwise regression,ordinary kriging,cokriging,kriging with external drift,kriging with varying local means,regression-kriging,ordinary artificial neural networks,and kriging combined with artificial neural networks,were compared to predict spatial variation of saturated hydraulic conductivity from environmental *** methods except ordinary kriging allow for inclusion of secondary *** secondary spatial information used was terrain attributes including elevation,slope gradient,slope aspect,profile curvature and contour curvature.A multiple jackknifing procedure was used as a validation *** mean square error (rMSE) and mean absolute error (MAE) were used as the validation indices,with the mean rMSE and mean MAE used to judge the prediction *** performance by ordinary kriging was poor,indicating that prediction of saturated hydraulic conductivity can be improved by incorporating ancillary data such as terrain *** combined with artificial neural networks performed *** prediction models made better use of ancillary information in predicting saturated hydraulic conductivity compared with the competing *** combination of geostatistical predictors with neural computing techniques offers more capability for incorporating ancillary information in predictive soil *** is great potential for further research and development of hybrid methods for digital soil mapping.

关键词： digital elevation model geostatistics soil hydraulic properties spatial mapping

Fuzzy-GA based algorithm for optimal placement and sizing of distribution static compensator (DSTATCOM) for loss reduction of distribution network considering reconfiguration

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Journal of Central South University 2017年第2期24卷 245-258页

作者： Mohammad mohammadi Mahyar Abasi A.mohammadi rozbahani Department of Electrical Engineering Borujerd Branch Islamic Azad University

This work presents a fuzzy based methodology for distribution system feeder reconfiguration considering DSTATCOM with an objective of minimizing real power loss and operating cost. Installation costs of DSTATCOM devices and the cost of system operation, namely, energy loss cost due to both reconfiguration and DSTATCOM placement, are combined to form the objective function to be minimized. The distribution system tie switches, DSTATCOM location and size have been optimally determined to obtain an appropriate operational condition. In the proposed approach, the fuzzy membership function of loss sensitivity is used for the selection of weak nodes in the power system for the placement of DSTATCOM and the optimal parameter settings of the DFACTS device along with optimal selection of tie switches in reconfiguration process are governed by genetic algorithm(GA). Simulation results on IEEE 33-bus and IEEE 69-bus test systems concluded that the combinatorial method using DSTATCOM and reconfiguration is preferable to reduce power losses to 34.44% for 33-bus system and to 45.43% for 69-bus system.

关键词： distribution FACTS (DFACTS) distribution static compensator (DSTATCOM) network reconfiguration genetic algorithm fuzzy membership function power loss reduction

Pure annihilation decay of strange beauty meson into two charm heavy mesons

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Chinese Physics C 2022年第2期46卷 62-69页

作者： Behnam mohammadi Department of Physics Urmia UniversityUrmiaIran

In this study,the heavy to heavy decay of D^(0)_(s)→D^(*+)D^(-)is evaluated through the factorization approach by using the final state interaction as an effective *** the factorization approach,this decay mode occurs only through the annihilation process,so a small amount is ***'s rules state that six meson pa.r. can be assumed for the intermediate states before the final meson pa.r. are *** taking into account the effects of twelve final state interaction dia.r.ms in the calculations,a significant correction is *** effects correct the value of the branching ratio obtained by the pure factorization approach from(2.41±1.37)×10^(-5)to(8.27土2.23)×10^(-5).The value obtained for the branching ratio of the D^(0)_(s)→D^(*+)D^(-)decay is consistent with the experimental results.

关键词： standard model factorization approach final state interaction

Numerical and experimental study of twin-fluid two-phase internal-mixing atomizer to develop maximum entropy method

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Chinese Journal of a.r.nautics 2020年第9期33卷 2281-2294页

作者： Alireza mohammadi Fathollah OMMI Department of Mechanical Engineering.Tarbiat Modares University Tehran 14115-111Iran

This paper presents an analytical, numerical, and experimental study on atomization characteristics and droplet distribution of a twin-fluid two-phase internal mixing atomizer to develop a Maximum Entropy Method(MEM). A two-phase Eulerian-La.r.ngian method is utilized for atomization modeling of the inside and outside atomizer. In order to modify energy and momentum sources in the MEM, parametric studies are performed, and experimental tests are ca.r.ed out to verify the results by applying the shadowgraph method. An advanced test stand is developed to prepare a wide range of changes in atomization characteristics and mixing ratios. A high degree of consistency is found between numerical results from the developed MEM and experimental tests with different gas-phase pressures and liquid flow rates. The droplet diameter and velocity distribution are reviewed based on various Weber numbers, sources of energy, and momentum. Turbulence modeling assists to estimate the breakup length and time scale precisely in the developed MEM, and distribution ranges with mean values are achieved. With reference to a strong correlation between upstream turbulence flow and the developed MEM verified by experimental tests, an ideal droplet size and velocity distribution prediction is observed.

关键词： Atomization Droplet distribution Internal-mixing atomizer Maximum entropy method Shadowgraph technique Test stand

Power loss reduction of distribution systems using BFO based optimal reconfiguration along with DG and shunt capacitor placement simultaneously in fuzzy framework

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Journal of Central South University 2017年第1期24卷 90-103页

作者： M.mohammadi A.mohammadi rozbahani S.Bahmanyar Department of Electrical Engineering Borujerd BranchIslamic Azad UniversityBorujerdIran

In distribution systems,network reconfiguration and capacitor placement are commonly used to diminish power losses and keep voltage profiles within acceptable ***,the problem of DG allocation and sizing is great *** this work,a combination of a fuzzy multi-objective approach and bacterial foraging optimization(BFO) as a meta-heuristic algorithm is used to solve the simultaneous reconfiguration and optimal sizing of DGs and shunt capacitors in a distribution *** objective is transferred into fuzzy domain using its membership ***,the overall fuzzy satisfaction function is formed and considered a fitness function inasmuch as the value of this function has to be maximized to gain the optimal *** numerical results show that the presented algorithm improves the performance much more than other meta-heuristic *** results found that simultaneous reconfiguration with DG and shunt capacitors allocation(case 5) has 77.41%,42.15%,and 56.14%improvements in power loss reduction,load balancing,and voltage profile indices,respectively in 33-bus test *** result found 87.27%,35.82%,and 54.34%improvements of mentioned indices respectively for 69-bus system.

关键词： network reconfiguration distributed generation (DG) capacitor banks fuzzy framework bacterial foragingoptimization

Solvent Effects on Complexation of Molybdenum（Ⅵ） with Nitrilotriacetic Acid in Different Aqueous Solutions of Propanol

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Chinese Journal of Chemistry 2007年第3期25卷 284-288页

作者： mohammadi Behrouz mohammadi Jalalb Chemistry Department Shahid Beheshti University Tehran Evin Iran Chemistry Department Tabriz University Tabriz Iran

By using spectrophotometric and potentiometric techniques the formation constants of the species formed in the systems H^＋＋ Mo（Ⅵ）＋nitrilotriacetic acid and H^＋＋ nitrilotriacetic acid have been determined in aqueous solutions of propanol at 25 ℃ and constant ionic strength 0.1 molodm^-3 sodium perchlorate. The composition of the complex was determined by the continuous variation method. It was shown that molybdenum（Ⅵ） forms a mononuclear 1 ： 1 complex with nitrilotriacetic acid of the type MoO3L^-3 at -lg[H^＋] =5.8. The formation constants in various media were analyzed in terms of Kamlet and Taft＇s parameters. Linear relationships were observed when lg Ks was plotted versusp. Finally, the results were discussed in terms of the effect of solvent on complexation.

关键词： solvent effect molybdenum(Ⅵ) nitrilotriacetic acid (NTA) propanol

Improving the Surface roughness of Dental Implant Fixture by Considering the Size,Angle and Spraying Pressure of Sandblast Particles

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Journal of Bionic Engineering 2024年第1期21卷 303-324页

作者： Ehsan Anbarzadeh Bijan mohammadi School of Mechanical Engineering Iran University of Science and TechnologyTehranIran

In this study,different conditions of sandblasting on dental implant fixtures were investigated to achieve the best sandblasting conditions.18 different sandblasting conditions(Using 152 implant fixture samples)were examined,including parameters such as particle size,particle blasting pressure,and particle blasting *** surface treatment of the samples was performed using the SLA+Anodizing *** testing was performed for each of the 18 different states,and the average surface roughness of each of these was compared with each ***,a bone layer was placed on the sample with the closest average surface roughness to the standard and the least amount of aluminum oxide on its surface among the 18 different states,to confirm the accuracy and quality of the desired surface roughness by examining the bone formation process and *** results showed that state No.4(sandblast particle size:75µm,spraying pressure of sandblast particles:4 bar,sandblast particle spraying angle:30 degrees),which was prepared using the SLA+Anodizing method and had a surface roughness of 1.989µm(The percentage of Al_(2)O_(3)on the surface=6%),had the best sandblasting conditions and showed 95%cell viability and accelerated the treatment and bone formation process for about a *** simulation results,using Abaqus software,indicated that the stress distribution on the surface of the implant fixture in contact with the bone surface has increased by approximately 4.3%for state *** will help prevent loosening of the dental implant fixture over time.

关键词： Dental implants Surface treatment Sandblast Surface roughness Osseointegration