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Effect of frequency and pulse-on time of high power impulse magnetron sputtering on deposition rate and morphology of titanium nitride using response surface methodology

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Transactions of Nonferrous Metals Society of China 2019年第12期29卷 2577-2590页

作者： Saeed GHASEMI ali reza farhadizadeh Hamid GHOMI Laser and Plasma Research Institute Shahid Beheshti University

Titanium nitride thin films were deposited on silicon by high power impulse magnetron sputtering(HiPIMS)method at different frequencies(162-637 Hz)and pulse-on time(60-322μs).Response surface methodology(RSM)was employed to study the simultaneous effect of frequency and pulse-on time on the current waveforms and the crystallographic orientation,microstructure,and in particular,the deposition rate of titanium nitride at constant time and average power equal to 250 *** crystallographic structure and morphology of deposited films were analyzed using XRD and FESEM,*** is found that the deposition rate of HiPIMS samples is tremendously dependent on pulse-on time and frequency of pulses where the deposition rate changes from 4.5 to 14.5 nm/*** regression equations and analyses of variance(ANOVA)reveal that the maximum deposition rate(equal to(17±0.8)nm/min)occurs when the frequency is 537 Hz and pulse-on time is 212μ*** experimental measurement of the deposition rate under this condition gives rise to the deposition rate of 16.7 nm/min that is in good agreement with the predicted value.

关键词： high powder impulse magnetron sputtering(HiPIMS) titanium nitride response surface methodology(RSM) deposition rate analyses of variance(ANOVA)

An ensemble method for data stream classification in the presence of concept drift

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Frontiers of Information Technology & Electronic Engineering 2015年第12期16卷 1059-1068页

作者： Omid ABBASZADEH ali AMIRI ali reza KHANTEYMOORI Department of Computer Engineering University of Zanjan

One recent area of interest in computer science is data stream management and processing. By ‘data stream', we refer to continuous and rapidly generated packages of data. Specific features of data streams are immense volume, high production rate, limited data processing time, and data concept drift; these features differentiate the data stream from standard types of data. An issue for the data stream is classification of input data. A novel ensemble classifier is proposed in this paper. The classifier uses base classifiers of two weighting functions under different data input conditions. In addition, a new method is used to determine drift, which emphasizes the precision of the algorithm. Another characteristic of the proposed method is removal of different numbers of the base classifiers based on their quality. Implementation of a weighting mechanism to the base classifiers at the decision-making stage is another advantage of the algorithm. This facilitates adaptability when drifts take place, which leads to classifiers with higher efficiency. Furthermore, the proposed method is tested on a set of standard data and the results confirm higher accuracy compared to available ensemble classifiers and single classifiers. In addition, in some cases the proposed classifier is faster and needs less storage space.

关键词： Data stream Classificaion Ensemble classifiers Concept drift

A sensitivity analysis and multi-objective optimization to enhance ethylene production by oxidative dehydrogenation of ethane in a membrane-assisted reactor

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Chinese Journal of Chemical Engineering 2018年第9期26卷 1879-1895页

作者： ali Darvishi ali Bakhtyari Mohammad reza Rahimpour Department of Chemical Engineering Shiraz University

Owing to the importance of process intensification in the natural gas associated processes, the present contribution aims to investigate the production of an important natural gas downstream product in an improved ***, a membrane-assisted reactor for the oxidative dehydrogenation of ethane is presented. The presented system includes a membrane for axial oxygen dosing into the reaction side. Such a strategy would lead to optimum oxygen distribution along the reactor length and prevention of hot spot formation as well. A feasibility study is conducted by developing a validated mathematical model composed of mass and energy balance equations. The effects of various operating variables are investigated by a rigorous sensitivity ***, by applying the genetic algorithm, a multi-objective optimization procedure is implemented to obtain the optimum operating condition. Considerable increase in the ethane conversion and ethylene yield are the advancements of membrane-assisted oxidative dehydrogenation reactor working under the optimum *** than 30% increase in the ethane conversion is obtained. Furthermore, the ethylene yield is enhanced up to 0.45.

关键词： Olefin ODH process Genetic algorithm Fixed-bed Mathematical modeling Chemical reactors

Aircraft robust multidisciplinary design optimization methodology based on fuzzy preference function

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Chinese Journal of Aeronautics 2018年第12期31卷 2248-2259页

作者： ali reza BABAEI Mohammad reza SETAYANDEH Hamid FARROKHFAL Department of Mechanical and Aerospace Engineering Malek-Ashtar University of Technology

This paper presents a Fuzzy Preference Function-based Robust Multidisciplinary Design Optimization(FPF-RMDO) methodology. This method is an effective approach to multidisciplinary systems, which can be used to designer experiences during the design optimization process by fuzzy preference functions. In this study, two optimizations are done for Predator MQ-1 Unmanned Aerial Vehicle(UAV):(A) deterministic optimization and(B) robust optimization. In both problems, minimization of takeoff weight and drag is considered as objective functions, which have been optimized using Non-dominated Sorting Genetic Algorithm(NSGA). In the robust design optimization, cruise altitude and velocity are considered as uncertainties that are modeled by the Monte Carlo Simulation(MCS) method. Aerodynamics, stability and control, mass properties, performance, and center of gravity are used for multidisciplinary analysis. Robust design optimization results show 46% and 42% robustness improvement for takeoff weight and cruise drag relative to optimal design respectively.

关键词： Fuzzy logic Multidisciplinary design optimization Preference function Robust design Unmanned Aerial Vehicle(UAV)

Modeling of unconfined compressive strength of soil-RAP blend stabilized with Portland cement using multivariate adaptive regression spline

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Frontiers of Structural and Civil Engineering 2019年第4期13卷 787-799页

作者： ali reza GHANIZADEH Morteza RAHROVAN Department of Civil Engineering Sirjan University of Technology Sirjan 78137-33385 Iran Department of Civil Engineering Yazd University Yazd 89195-741 Iran

The recycled layer in full-depth reclamation (FDR) method is a mixture of coarse aggregates and reclaimed asphalt pavement (RAP) which is stabilized by a stabilizer agent. For design and quality control of the final product in FDR method, the unconfined compressive strength of stabilized material should be known. This paper aims to develop a mathematical model for predicting the unconfined compressive strength (UCS) of soil-RAP blend stabilized with Portland cement based on multivariate adaptive regression spline (MARS). To this end, two different aggregate materials were mixed with different percentages of RAP and then stabilized by different percentages of Portland cement. For training and testing of MARS model, total of 64 experimental UCS data were employed. Predictors or independent variables in the developed model are percentage of RAP, percentage of cement, optimum moisture content, percent passing of #200 sieve, and curing time. The results demonstrate that MARS has a great ability for prediction of the UCS in case of soil-RAP blend stabilized with Portland cement (R2 is more than 0.97). Sensitivity analysis of the proposed model showed that the cement, optimum moisture content, and percent passing of #200 sieve are the most influential parameters on the UCS of FDR layer.

关键词： full-depth reclamation soil-reclaimed asphalt pavement blend Portland cement unconfined compressive strength multivariate adaptive regression spline

Electrophoretic deposition and an investigation of co-dopants effect on luminescence property of Mg2SiO4:Eu3+phosphors

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Journal of Rare Earths 2017年第12期35卷 1171-1179页

作者： Mehdi Ghahari ali reza Naeimi Department of Nanomaterials and Nano Coatings Institute for Color Science and TechnologyTehranIran

Forsterite particles doped with europium ions（Eu^（3＋）） were synthesized via a solution combustion method. The effect of co-dopants on photoluminescence intensity was described. Different percentages of calcium（Ca^（2＋））, zinc（Zn^（2＋））, barium（Ba^（2＋）） and strontium（Sr^（2＋）） were added to the Mg2SiO4：Eu^（3＋）*** synthesized sample was characterized by X-ray diffraction, transmission electron microscopy,scanning electron microscopy, spectrofluorometer and the FTIR spectroscopy. X-ray diffraction（XRD）results revealed that dominant phase was forsterite in all samples. Additionally, a negligible amount of periclase phase was recognized in the samples. The average size of the synthesized particles was less than 200 nm. The presence of co-dopant led to an enhancement in the photoluminescent property of the synthesized samples. The maximum increase in photoluminescence intensity was obtained by Ba^（2＋）ions as a co-dopant. Condensed films of photoluminescence particles were produced by utilizing electrophoresis technique to deposit particles. The results showed that polyvinyl pyrrolidone was the best surface modifier to raise the mass deposition of the samples on the substrate.

关键词： Luminescence materials Forsterite Combustion syntheses Electrophoretic deposition

Numerical analysis of reactive turbulent flow in the thrust chamber of RD-108 engine rocket

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Defence Technology（防务技术） 2019年第4期15卷 565-575页

作者： Seyed reza Taghavi Mohammad ali Dehnavi ali Ghafouri Department of Chemical Engineering Imam Hossein Comprehensive University

Combustion chamber modeling and simulation of the liquid propellant engine with kerosene as fuel and liquid oxygen as an oxidizer in the turbulent flow field are performed by CFD *** flow is modeled as Single-phase in steady state and using RNG k-ε turbulence *** results are validated by experimental data of thrust,special impulse and combustion chamber *** comparing t.^wo reaction models of finite rate chemistry and frozen model with experimental data,it is concluded that finite rate chemistry has acceptable *** optimum value of equivalence ratio(oxidizer to fuel ratio)per reaction and operational parameters of the engine which maximize thrust and special impulse are determined.

关键词： Liquid propellant engine Computational fluid dynamics(CFD) Kerosene and oxygen Freeze model Finite rate chemistry model

Detection mechanism and classification of design principles of peroxidase mimic based colorimetric sensors: A brief overview

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Chinese Journal of Chemical Engineering 2020年第6期28卷 1492-1503页

作者： ali reza Hormozi Jangi Mohammad reza Hormozi Jangi Saeed reza Hormozi Jangi Department of Chemistry College of SciencesShiraz UniversityShiraz 71454Iran

Synthesis and characterization of enzyme mimics with characteristic stability and high catalytic efficiency is an interesting field for ***,with the development of nanoscience and introducing of Fe3O4 magnetic nanoparticles as peroxidase mimics in 2007,various nanomaterials such as noble metals,metal oxides,and carbon materials were introduced as enzyme mimics(nanozymes).Various nanomaterials exhibit peroxidaselike activity,hence,most of the nanozymes are peroxidase *** the nanozyme based sensors were previously classified,the classifications have been focused on the type of nanozyme ***,the nanozyme based sensors were classified as peroxidase,hydrolase,and urease mimic-based ***,heretofore,these sensors are not classified based on the detection mechanism and principles of system *** aim of this review is the focus on the peroxidase mimic based colorimetric sensors as the most common nanozyme-based sensors and their classification based on principles of sensor design and review of the detection mechanism of the current mimic peroxidase based ***,some current challenges and future developments in this field are discussed.

关键词： Peroxidase mimic Nanozyme Enzyme-peroxidase mimic hybrids HP sensing pH sensing Enzyme co-embedded nanomaterials

Lattice parameters of Ti–4Al–2V alloy with thermal oxidation

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Rare Metals 2016年第2期35卷 149-153页

作者： Faraz Omidbakhsh ali reza Ebrahimi Department of Mechanical Engineering Tabriz Branch Islamic Azad University Mining and Metallurgical Engineering Department Amirkabir University of Technology

In this study, the effect of thermal oxidation on the lattice parameters of Ti-4Al-2V alloy was *** were oxidized at 450, 600 and 650 °C for 1-7 h in electric furnace under air atmosphere. The lattice parameters were determined using the Cohen method as a function of oxidation time at each temperature. The lattice parameters of as-received alloy are calculated as a = 0.29289 nm and c = 0.46652 nm. The thermal oxidation at 450 °C results in a gradual increase in a-parameter, whereas it goes through a maximum at higher temperatures（600 and 700 °C）. The results show that these maximums are reduced to an approximately constant value after a long-time oxidation. The c-parameter generally increases over the whole treatment condition. It is believed that these variations could be due to the dissolution of oxygen atoms in octahedral sites of hcp lattice of titanium.

关键词： Lattice parameter Ti-4Al-2V X-ray diffraction Cohen method Octahedral sites