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Effect of milling atmosphere on structural and magnetic properties of Ni-Zn ferrite nanocrystalline

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Chinese Physics B 2015年第4期24卷 481-490页

作者： Abdollah Hajalilou Mansor Hashim Reza Ebrahimi-Kahrizsangi Mohamad taghi Masoudi Material Synthesis and Characterization Laboratory Institute of Advanced Technology (ITMA)Universiti Putra Malaysia Advanced Materials Research Center Materials Engineering Department Najafabad Branch Islamic Azad University

Powder mixtures of Zn, NiO, and Fe2O3 are mechanically alloyed by high energy ball milling to produce Ni-Zn ferrite with a nominal composition of Ni0.36Zn0.64Fe2O4. The effects of milling atmospheres （argon, air, and oxygen）, milling time （from 0 to 30 h） and heat treatment are studied. The products are characterized using x-ray diffractometry, field emission scanning electron microscopy equipped with energy-dispersive x-ray spectroscopy, and transmitted electron microscopy. The results indicate that the desired ferrite is not produced during the milling in the samples milled under either air or oxygen atmospheres. In those samples milled under argon, however, Zn/NiO/Fe2O3 reacts with a solid-state diffusion mode to produce Ni-Zn ferrite nanocrystalline in a size of 8 nm after 30-h-milling. The average crystallite sizes decrease to 9 nm and 10 nm in 30-h-milling samples under air and oxygen atmospheres, respectively. Annealing the 30-h-milling samples at 600℃ for 2 h leads to the formation of a single phase of Ni-Zn ferrite, an increase of crystallite size, and a reduction of internal lattice strain. Finally, the effects of the milling atmosphere and heating temperature on the magnetic properties of the 30-h-milling samples are investigated.

关键词： Ni-Zn ferrite nanocrystalline mechanical alloying milling atmosphere milling time magnetic property

Simultaneous Determination of Bismuth,Lead,and Iron in Water Samples by Optimization of USAEME and ICP–OES via Experimental Design

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Journal of Analysis and Testing 2018年第1期2卷 98-105页

作者： taghi Sahraeian Hassan Sereshti Ahmad Rohanifar Department of Chemistry and Biochemistry The Ohio State UniversityColumbusOH 43210USA Department of Chemistry Faculty of ScienceUniversity of TehranTehranIran

Ultrasound-assisted emulsification–microextraction followed by inductively coupled plasma–optical emission spectrometry was utilized for simultaneous pre-concentration and trace detection of lead,bismuth,and iron in water *** N,N-bis(salicylidene)ethylenediamine and trichloroethylene were used as chelating agent and extraction solvent,*** parameters of interest were volume of extraction solvent,temperature,and concentrations of salt and chelating agent.A fractional factorial design was developed to identify these parameters and how they vary with one *** results demonstrated that the concentrations of salt and chelating agent affected extraction ***,a central-composite design was used to acquire optimum levels of effective *** optimal conditions were 160.7 mg L^(−1) and 1.77%(w/v)for concentration of chelating agent and salt,*** linear dynamic ranges were determined to be 1–1000μg L^(−1) for Pb and Bi,and 10–1000μg L^(−1) for *** correlation coefficient(R2)was 0.990–*** limits of detection were 0.54–0.78μg L^(−1).The relative standard deviation(concentration=200μg L^(−1),n=8)was in the range of 2.0–4.3%.This method was successfully applied for the trace detection of Pb,Bi,and Fe in freshwater samples of waterfall and spring and satisfactory relative recoveries(96.2–99.6%)were obtained.

关键词： Ultrasound-assisted emulsification-microextraction Bismuth Lead Iron Disodium N N-bis(salicylidene)ethylenediamine Inductively coupled plasma-optical emission spectroscopy Experimental design

Soft sensor design for hydrodesulfurization process using support vector regression based on WT and PCA

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Journal of Central South University 2015年第2期22卷 511-521页

作者： Saeid Shokri Mohammad taghi Sadeghi Mahdi Ahmadi Marvast Shankar Narasimhan Department of Chemical Engineering Iran University of Science and Technology (IUST) Tehran 16765?163 Iran Process & Equipment Technology Development Division Research Institute of Petroleum Industry (RIPI) Tehran 14665?137 Iran Department of Chemical Engineering IIT Madras Chennai 600036 India

A novel method for developing a reliable data driven soft sensor to improve the prediction accuracy of sulfur content in hydrodesulfurization(HDS) process was proposed. Therefore, an integrated approach using support vector regression(SVR) based on wavelet transform(WT) and principal component analysis(PCA) was used. Experimental data from the HDS setup were employed to validate the proposed model. The results reveal that the integrated WT-PCA with SVR model was able to increase the prediction accuracy of SVR model. Implementation of the proposed model delivers the best satisfactory predicting performance(EAARE=0.058 and R2=0.97) in comparison with SVR. The obtained results indicate that the proposed model is more reliable and more precise than the multiple linear regression(MLR), SVR and PCA-SVR.

关键词： soft sensor support vector regression principal component analysis wavelet transform hydrodesulfurization process

Sustainable functionalization and modification of materials via multicomponent reactions in water

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Frontiers of Chemical Science and Engineering 2022年第9期16卷 1318-1344页

作者： Siamak Javanbakht Tahereh Nasiriani Hassan Farhid Mohammad taghi Nazeri Ahmad Shaabani Department of Organic Chemistry Shahid Beheshti UniversityTehran ***Iran Рeoples’Friendship University of Russia(RUDN University) Moscow 117198Russian Federation

In materials chemistry,green chemistry has established firm ground providing essential design criteria to develop advanced tools for efficient functionalization and modification of ***,the combination of multicomponent reactions in water and aqueous media with materials chemistry unlocks a new sustainable way for constructing multi-functionalized structures with unique features,playing significant roles in the plethora of *** reactions have received significant consideration from the community of material chemistry because of their great efficiency,simple operations,intrinsic molecular diversity,and an atom and a pot ***,by rational design of multicomponent reactions in water and aqueous media,the performance of some multicomponent reactions could be enhanced by the contributing“natural”form of water-soluble materials,the exclusive solvating features of water,and simple separating and recovering *** date,there is no exclusive review to report the sustainable functionalization and modification of materials in *** critical review highlights the utility of various kinds of multicomponent reactions in water and aqueous media as green methods for functionalization and modification of siliceous,magnetic,and carbonaceous materials,oligosaccharides,polysaccharides,peptides,proteins,and synthetic *** detailed discussion of synthetic procedures,properties,and related applicability of each functionalized/modified material is fully deliberated in this review.

关键词： materials multicomponent reactions modification functionalization water

Dynamic observer-based controllers for linear uncertain systems

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控制理论与应用（英文版） 2013年第2期11卷 193-199页

作者： Arash GOLABI Mohammad taghi Hamidi BEHESHTI Mohammad Hasan ASEMANI Department of Electrical and Computer Engineering Tarbiat Modares University

This paper addresses robust controller design for uncertain linear systems via a dynamic observer-based controller. A dynamic observer is an alternative structure for a classical observer which can be regarded as a general form of a usual observer and has additional degrees of freedom in the observer structure. Using this new observer structure, a new observer-based controller for linear systems is proposed. Some strict linear matrix inequalities （LMIs） have been given to find the dynamic observer parameters and controller gain. It is shown that dynamic observer can be used effectively for tackling the drawbacks of the classical observer-based robust controller design methods. As an advantage, LMIs are derived even in the presence of uncertainties in system, input and output matrices simultaneously, whereas by using the traditional observer, bilinear matrix inequalities （BMIs） are given in the presence of such uncertainties. Moreover, the proposed LMIs do not imply the equality constraint. Simulation results are used to illustrate the effectiveness of the proposed design technique.

关键词： Dynamic observer Uncertain systems Linear matrix inequality (LMI) Robust control Output feedbackcontrol

Evaluation of total load sediment transport formulas using ANN

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International Journal of Sediment Research 2009年第3期24卷 274-286页

作者： Chih Ted YANG Reza MARSOOLI Mohammad taghi AALAMI Water Resources Colorado State University Graduate student of Civil-Hydraulics Engineering University of Tabriz Civil-Hydraulics Engineering University of Tabriz

The calculated results from various sediment transport formulas often differ from each other and from measured data. Some parameters in the sediment transport formulas are more effective than others to estimate total sediment load. In this study, an Artificial Neural Network (ANN) model is trained using four dominant parameters of sediment transport formulas. ANN models are able to reveal hidden laws of natural phenomena such as sediment transport process. The results of ANN and some total bed material load sediment transport formulas have been compared to indicate the importance of variables which can be used in developing sediment transport formulas. To train ANN, average flow velocity, water surface slopes, average flow depth, and median particle diameter are used as dominant parameters to estimate total bed material load. Two hundreds and fifty samples are used to train the ANN model. Twenty-four sets of field data not used in the training nor calibration of ANN are used to compare or verify the accuracy of ANN and some well-known total bed material load formulas. The test results show that the ANN model developed in this study using minimum number of dominant factors is a reliable and uncomplicated method to predict total sediment transport rate or total bed material load transport rate. Results show that the accuracy of formulas in descending order are those by Yang (1973), Laursen (1958), Engelund and Hansen (1972), Ackers and White (1973), and Toffaleti (1969). These results are similar to those made by ASCE (1982) based on laboratory and field data not used in this paper. Study results also show that the formulas based on physical laws of sediment transport, like those formulas that were developed based on power concept, are more accurate than other formulas for estimating total bed material sediment load in rivers.

关键词： Artificial Neural Network (ANN) Total bed material load Sediment transport formulas

Mineralogical and sink-float studies of Jajarm low-grade bauxite

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International Journal of Minerals,Metallurgy and Materials 2010年第3期17卷 251-256页

作者： Mohammad Zarbayani Esmaeil Jorjani Mirsaleh Mirmohammadi Mohammad taghi Shadloo Mohammad Noaparast Science and Research Branch Islamic Azad University School of Mining Engineering University of Tehran Jajarm Alumina Company

Jajarm＇s bauxite deposits are mainly diasporic, and they have a low mass ratio of Al2O3/SiO2. It is necessary to increase the run-of-mine mass ratio before feeding the material to the Bayer process. Chemical analysis indicated that the low-grade bauxite sample from Jajarm contained 43.9wt% Al2O3 and 13.35wt% SiO2, resulting in a mass ratio of 3.29. According to mineralogical studies, the presence of aluminosilicate minerals such as kaolinite, illite, and quartz was the main reason for the decrease of the mass ratio. Microscopic observations revealed that, with the size reduction from -1000＋710 to -38 μm, the liberation degree of diaspore increased from 10% to 60%, and that of aluminosilicates increased from 20% to 85%. Heavy liquids with the densities of 2.8, 3.0, 3.2, and 3.4 g/cm3 were used to evaluate the heavy media separation in three sizes, i.e., -3350＋710, -710＋212, and -212＋125 μm. Laboratory studies confirm that the density of 3.2 g/cm3 can produce the concentrates （in sunk fractions） with recoveries of 89.09%, 91.24%, and 84.68% with the Al2O3/SiO2 mass ratios of 5.03, 5.16, and 5.15 for the -3350＋710, -710＋212, and -212＋ 125 μ m sizes, respectively.

关键词： bauxite diaspore aluminosilicate mass ratio heavy media

Fabrication of (Ti,Hf)-rich NiTiHf Alloy Using Graphitic Mold and Crucible

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Journal of Materials Science & Technology 2014年第3期30卷 280-284页

作者： Mahdi Moshref-Javadi Majid Belbasi Seyed Hossein Seyedein Mohammad taghi Salehi School of Metallurgy & Materials Engineering Iran University of Science & Technology (IUST)

In this research, fabrication of a （Ti,Hf）-rich NiTiHf alloy by using vacuum induction melting （VIM） process and a graphitic crucible was investigated. For this purpose, casts with the nominal composition of Ni49Ti38Hf15 were prepared in graphitic crucible and mold. Optical microscopy （OM）, scanning electron microscopy （SEM）, energy dispersive X-ray spectroscopy （EDS）, X-ray diffraction （XRD）, and differential scanning calorimetry （DSC） tests were employed to characterize the samples. Results demonstrated that microstructure of the first cast was composted of a B2 austenite phase as well as a great amount of two differently formed （Ti,Hf）C carbides. Moreover, no austenite ＊-＊ martensite transformation peak was detected in the DSC curve of this sample, indicating a drastic decline in the transformation temperatures. In the succeeding cast, however, owing to the formation of carbide layers on the inner surfaces of the graphitic crucible and mold during the initial casting process, the amounts of carbides decreased remarkably. This cast exhibited transformation temperatures above 100℃, while XRD pattern denoted the presence of B19t monoclinic martensite phase at room temperature. All in all, results confirmed that VIM process using graphitic mold and crucible can be considered as an appropriate method for the fabrication of （Ti,Hf）-rich NiTiHf high temperature shape memory alloys.

关键词： High temperature shape memory alloys NiTi Martensite Casting Transformation temperatures Microstructure

Task Allocation Approach for Minimizing Make-Span inWireless Sensor Actor Networks

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Computer Systems Science & Engineering 2021年第11期39卷 165-178页

作者： Mohammad Reza Okhovvat Mohammad taghi Kheirabadi Ali Nodehi Morteza Okhovvat Department of Computer Engineering Gorgan BranchIslamic Azad UniversityGorganIran Health Management and Social Development Research Center Golestan University of Medical SciencesGorganIran

Wireless Sensor Actor Networks(WSANs)have contributed to the development of pervasive computing wherein time consideration to perform the tasks of pervasive applications is ***,time constraint is one of the major challenges of *** this paper,we propose an analytical approach based on queuing theory to minimize the total time taken for completion of tasks,i.e.,make-span,in WSANs with hybrid *** best allocation rates of tasks to actor nodes are figured out through solving inequities and qualities resulting from a steady state analysis of the proposed *** the calculated tasks arrival rates at each of the actors,the make-span could be *** assess the accuracy of the tasks assignment rates to each of the actors attained from the suggested analytical approach and to provide a graphical representation of the WSAN a formal model in terms of the generalized stochastic Petri net(GSPN)is *** proposed GSPN model is analyzed,tasks distribution weights to the actors are determined,and then tasks allocation rates can be *** the results achieved from the analytical approach and the GSPN model demonstrates that allocation rates and hence,the make-span figured out from proposed approach and the formal model are the *** results in typical scenarios show shorter make-span and longer network lifetime compared to when one of the two popular traditional task allocation algorithms,namely,opportunistic load balancing(OLB),and stochastic allocation(SA)algorithms,is used.

关键词： GSPN make-span optimization queuing system task allocation