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Selective Synthesis of 2-Aryl-l-benzylated-1 H-benzimidazoles

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Chinese Journal of Chemistry 2011年第11期29卷 2389-2393页

作者： Shaterian, hamid reza Fahimi, Nafiseh Azizi, Kobra Department of Chemistry Faculty of Sciences University of Sistan and Baluchestan PO Box 98135-674 Zahedan lran

An efficient and simple procedure was developed for the green synthesis of various 2-aryl-l-ben- zylated-1H-benzimidazoles in high yields by condensation of o-phenylenediamine with aldehydes with P2O5/SiO2 as catalyst... 详细信息

关键词： synthetic methods aldehydes one-pot benzimidazoles heterogeneous catalyst solvent-free

An investigation on the ground motion parameters and seismic response of underground structures

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Earthquake Science 2012年第3期25卷 253-261页

作者： hamid reza Nejati Morteza Ahmadi hamid Hashemolhosseini Rock Mechanics Department School of Engineering Tarbiat Modares University Tehran 14117-13116 Iran Mining Engineering Department Isfahan University of Technology Isfahan 84156-83111 Iran

Peak ground acceleration (PGA), frequency content and time duration are three fundamental parameters of seismic loading. This study focuses on the seismic load frequency and its effect on the underground structures. Eight accelerograms regarding different occurred earthquakes that are scaled to an identical PGA and variation of ground motion parameters with ratio of peak ground velocity (PGV) to PGA, as a parameter related to the load frequency, are considered. Then, concrete lining response of a circular tunnel under various seismic conditions is evaluated analytically. In the next, seismic response of underground structure is assessed numerically using two different time histories. Finally, effects of incident load frequency and frequency ratio on the dynamic damping of geotechnical materials are discussed. Result of analyses show that specific energy of seismic loading with identical PGA is related to the seismic load frequency. Furthermore, incident load frequency and natural frequency of a system have influence on the wave attenuation and dynamic damping of the system.

关键词： ground motion parameter load frequency PGA dynamic analysis wave attenuation

Review on chemical enhanced oil recovery using polymer flooding: Fundamentals, experimental and numerical simulation

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Petroleum 2020年第2期6卷 115-122页

作者： Ali Mohsenatabar Firozjaii hamid reza Saghafi Department of Petroleum Engineering Petroleum University of TechnologyAbadanIran IOR/EOR Research Institute National Iranian Oil CompanyTehranIran

The EOR techniques are employed to recover more oil from mature reservoirs after the primary and secondary oil production *** flooding as a chemical EOR method involves adding polymer molecules in order to increase water *** water viscosity will improve the mobility ratio of injected fluid to reservoir fluid toward a more favorable ***,vertical and areal sweep efficiencies are increased compared to typical water *** flooding will be most effective if applied in the early stages of a water flood while the mobile oil saturation is still *** is also a critical component when considering other chemical EOR technologies such as alkaline-polymer or *** present study covers two main *** the first part,fundamental of polymer flooding as it related to experimental work and simulation are *** challenge of polymer flooding applications in high temperature and high salinity(HTHS)environment is also discussed in this *** the second part,the synergy of polymer with surfactant and alkaline as chemical enhancing oil recovery(CEOR)methods is discussed.

关键词： Polymer flooding Enhancing oil recovery Mobility control HPAM TVP

Dynamic task scheduling modeling in unstructured heterogeneous multiprocessor systems

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第6期15卷 423-434页

作者： hamid TABATABAEE Mohammad reza AKBARZADEH-T Naser PARIZ Department of Computer Engineering Islamic Azad University Center of Excellence on Soft Computing and Intelligent Information Processing Ferdowsi University of Mashhad Department of Electrical Engineering Ferdowsi University of Mashhad

An algorithm is proposed for scheduling dependent tasks in time-varying heterogeneous multiprocessor systems, in which computational power and links between processors are allowed to change over time. Link contention is considered in the multiprocessor scheduling problem. A linear switching-state space-modeling paradigm is introduced to enable theoretical analysis from a system engineering perspective. Theoretical analysis of this model shows its robustness against changes in processing power and link failure. The proposed algorithm uses a fuzzy decision-making procedure to handle changes in the multiprocessor system. The efficiency of the proposed algorithm is illustrated by several random experiments and comparison against a recent benchmark approach. The results show up to 18% average improvement in makespan, especially for larger scale systems.

关键词： Dynamic task scheduling Fuzzy logic Genetic algorithms Unstructured environment Linear switching state space

Fault ride-through capability improvement in a DFIG-based wind turbine using modified ADRC

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Protection and Control of Modern Power Systems 2022年第1期7卷 751-787页

作者： Seyed reza Mosayyebi Seyed hamid Shahalami Hamed Mojallali Electrical Engineering Department Faculty of EngineeringUniversity of GuilanRashtIran

In this paper,an overview of several strategies for fault ride-through(FRT)capability improvement of a doubly-fed induction generator(DFIG)-based wind turbine is *** and parameter variations have adverse effects on the performance of these *** is desirable to use a control method that is robust to such *** disturbance rejection control(ADRC)is one of the most common methods for eliminating the effects of *** improve the performance of the conventional ADRC,a modified ADRC is introduced that is more robust to disturbances and offers better *** non-derivability of the fal function used in the conventional ADRC degrades its efficiency,so the modified ADRC uses alternative functions that are derivable at all points,i.e.,the odd trigonometric and hyperbolic functions(arcsinh,arctan,and tanh).To improve the effciency of the proposed ADRC,fuzzy logic and fractional-order functions are used *** fuzzy fractional-order ADRC(FFOADRC),all disturbances are evaluated using a nonlinear fractional-order extended state observer(NFESO).The performance of the suggested structure is investigated in MATLAB/*** simulation results show that during disturbances such as network voltage sag/swell,using the modified ADRCs leads to smaller fluctuations in stator flux amplitude and DC-link voltage,lower variations in DFIG velocity,and lower total harmonic distortion(THD)of the stator *** demonstrates the superiority over conventional ADRC and a proportional-integral(PI)***,by chang-ing the crowbar resistance and using the modified ADRCs,the peak values of the waveforms(torque and currents)can be controlled at the moment of fault occurrence with no significant distortion.

关键词： Doubly-fed induction generator(DFIG) Auto disturbance rejection control(ADRC) Fault ride-through(FRT) Wind turbine Nonlinear fractional-order extended state observer(NFESO)

The kinetic of mass loss of grades A and B of melted TNT by isothermal and non-isothermal gravimetric methods

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Defence Technology（防务技术） 2018年第2期14卷 126-131页

作者： hamid reza Pouretedal Sajjad Damiri Parvaneh Nosrati Ehsan Forati Ghaemi Faculty of Applied Chemistry Malek-ashtar University of Technology

The kintic and activation energy of mass loss of two grades of melted TNT explosive, grade A and grade B, with freezing points of 80.57 and 78.15 ℃, respectively, were studied by isothermal and nonisothermal gravimetric methods. In isothermal method, the mass loss of samples in containers of glass and aluminum was followed in temperatures of 80, 90 and 100 ℃. The kinetic of the mass loss of the samples in the aluminum container was higher than the kinetic of it in the glass container that can be related to the effects of heat transfer and catalytic of aluminm metal. Also, the presence of impurities in grade B was due to increasing of kinetic of mass loss of it versus grade A. The non-isothermal curves were obtained in range of 30-330 ℃ at heating rates of 10,15 and 20 ℃·min^(-1).The TG/DTG data were used for determination of activation energy(E_a) of mass loss of TNT samples upon degradation by using Ozawa, Kissinger, Ozawa-Flynn-Wall(OFW) and Kissinger-Akahira-Sunose(KAS) methods as model free methods. The activation energies of grades of A and B of TNT was obtained 99-120 and 66-70 kJ mol^(-1)respectively. The lower values of activation energy of the degradation reaction of grade B confirm the effect of impurities in the kinetics of mass loss of this grade.

关键词： TNT Isothermal Non-isothermal Kinetic Mass loss

Kinetics and mechanism of titanium hydride powder and aluminum melt reaction

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International Journal of Minerals,Metallurgy and Materials 2012年第2期19卷 165-172页

作者： Ali Rasooli Mehdi Divandari hamid reza Shahverdi Mohammad Ali Boutorabi School of Metallurgy and Materials Engineering Member of Center of Excellence for Advanced Material and Processing (CEAMP) Iran University of Science and Technology Tehran 16844 Iran Department of Materials Faculty of Engineering Tarbiat Modaress University Tehran 14115-143 Iran

Based on the measurement of the released hydrogen gas pressure （PH2）, the reaction kinetics between TiH2 powder and pure aluminum melt was studied at various temperatures. After cooling the samples, the interface of TiH2 powder and aluminum melt was studied. The results show that the-time curves have three regions; in the first and second regions, the rate of reaction conforms zero and one order, respectively; in the third region, the hydrogen gas pressure remains constant and the rate of reaction reaches zero. The main factors that control the rate of reaction in the first and second regions are the penetration of hydrogen atoms in the titanium lattice and the chemical reaction between molten aluminum and titanium, respectively. According to the main factors that control the rate of reaction, three temperature ranges are considered for the reaction mechanism：（a） 700-750°C, （b） 750-800°C, and （c） 800-1000°C. In the first temperature range, the reaction is mostly under the control of chemical reaction; at the temperature range of 750 to 800°C, the reaction is controlled by the diffusion and chemical reaction; at the third temperature range （800-1000°C）, the dominant controlling mechanism is diffusion.

关键词： titanium hydride aluminum reaction kinetics reaction rate constants

Multi-scale analysis of flow structures in fluidized beds with immersed tubes

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Particuology 2015年第4期13卷 99-106页

作者： hamid R.Norouzi Maryam Tahmasebpoor reza Zarghami Navid Mostoufi Multiphase Systems Research Lab.School of Chemical Engineering College of EngineeringUniversity of Tehran Department of Chemical and Petroleum Engineering University of Tabriz

Multi-scale analysis and non-linear analysis were combined to investigate the hydrodynamics of fluidized beds with and without horizontal tubes. Pressure fluctuations were measured and analyzed employing discrete wavelet analysis, recurrence plot analysis, and recurrence quantification analysis. A systematic procedure was followed to determine wavelet parameters. At low gas velocities, the energy of macro-structures reduces with the addition of the first tube and then increases with the addition of a second tube. However, there is no notable difference at high gas velocities. Determinism is high for the bed without tubes, which can be attributed to the periodic behavior of bubbles. Determinism decreases with the addition of tubes because the breakage of bubbles results in less periodic behavior. The three methods of analysis used in this study captured the effects of immersed tubes on the hydrodynamics of fluidized beds. Recurrence quantitative analysis was found to be a powerful and easy-to-use method that can capture the nonlinear characteristics of fluidized beds much more quickly than conventional methods of nonlinear analysis. This method can thus be effectively used for the online monitoring of hydrodynamic changes in fluidized beds.

关键词： Immersed tube Non-linear analysis Pressure fluctuations Recurrence plot Wavelet transform

Effects of chelating agents on the sol-gel synthesis of nano-zirconia:Comparison of the Pechini and sugar-based methods

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International Journal of Minerals,Metallurgy and Materials 2020年第5期27卷 693-702页

作者： Faramarz Kazemi Farzin Arianpour Mahdiar Taheri Ali Saberi hamid reza rezaie Department of Mining and Metallurgy Amirkabir University of TechnologyTehranIran Research and Application Center Kastamonu UniversityKastamonuTurkey College of Engineering and Computer Science The Australian National UniversityCanberraAustralia Materials Processing Faculty of Engineering ScienceUniversity of BayreuthBayreuthGermany School of Metallurgy and Materials Engineering Iran University of Science and TechnologyTehranIran

This study focused on the comparison of the Pechini and sugar-based combustion synthesis methods to produce nano-zirconia. Zirconium hydroxide was utilized as metal precursor and citric acid, sucrose, and fructose were used as chelating agents, followed by calcination at 500, 600, and 700°C in air, respectively. Characterization was conducted by thermal analysis, specific surface area measurement, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning and transmission electron microscopy. When sucrose and citric acid were used as chelating agents during synthesis, mixtures of monoclinic and tetragonal phases were formed after calcination at 600 and 700°C. In the fructose samples, the tetragonal structure was the unique characterized phase. The tetragonal parameters in the fructose samples were determined using the diffraction data and the lattice parameter ratio was proven to increase with the temperature increase. Compared with the citrate and sucrose samples, the largest specific surface area(27 m2·g-1) and smallest particle size(39.1 nm) were obtained for the fructose sample after calcination at 700°C. The study revealed the formation of single-phase stabilized tetragonal zirconia using fructose as chelating agent after calcination at 500°C, and the presence and formation mechanism of stabilized tetragonal phase were also discussed on the basis of the X-ray and electron diffraction studies.

关键词： zirconia nanopowder sol-gel sugar Pechini chelation