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Nano-Micro Letters 2012年第2期4卷 83-89页

作者： Mohammad.Edrissi ahmad reza keshavarz Chemical Engineering Department Amirkabir University of Technology

Pure greenish-blue cobalt chromite(Co Cr/_2O_4) nanoparticles with narrow particle range of 4.1±1.9nm and surface area of 78.2 m2·g-1were synthesized through mixed chelates thermolysis of corresponding metals using 2-Mercaptopyridine N-oxide sodium salt as chelating agent. During the thermolysis procedure,high amount of gases were emitted that led to the formation of nanoparticles with high surface area. The product was characterized by TGA, DTG, XRD, TEM, SEM, LLS, BET and chemical analysis. Design of experiments was performed to fulfill the two levels L_4 Taguchi design. It was found that the temperature and time of thermolysis process have significant effect on the particle size reduction. The Oxidation of trichloroethylene was carried out over Co Cr_2O_4 nanocrystallite. Catalytic activity analysis revealed that the synthesis Co Cr_2O_4 possesses high catalytic activity for this process.

关键词： CoCr2O4 Nanoparticle Chelates Termolysis Taguchi experimental design Combustion of trichloroethylene

Preparation of nanocrystalline γ-Al_2O_3 catalyst using different procedures for methanol dehydration to dimethyl ether

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Journal of Natural Gas Chemistry 2011年第3期20卷 334-338页

作者： ahmad reza keshavarz Mehran rezaei Fereydoon Yaripour Catalyst and Advanced Materials Research Laboratory Chemical Engineering Department Faculty of Engineering University of Kashan Institute of Nanoscience and Nanotechnology University of Kashan Catalyst Research Group Petrochemical Research & Technology Company National Petrochemical Company (NPC)

A series of nanocrystalline γ-alumina are synthesized by different procedures, namely, thermal decomposition method （sample A）, precipita-tion method （sample B） and sol-gel method using sucrose and hexadecyltrimethyl ammonium bromide （CTAB） as templates （samples C and D, respectively）. Textural and acidic properties of γ-alumina samples are characterized by XRD, N2 adsorption-desorption and NH3-TPD techniques. Vapor-phase dehydration of methanol into dimethyl ether is carried out over these samples. Among them, sample C shows the highest catalytic activity. NH3-TPD analysis reveals that the sample with smaller crystallite size possesses higher concentration of medium acidic sites and consequently higher catalytic activity. Thermal decomposition method leads to decrease in both surface area and moderate acidity, therefore it is the cause of lower catalytic activity.

关键词： methanol dehydration dimethyl ether gama alumina sol-gel

Assessment of electrostatic discharge sensitivity of nitrogen-rich heterocyclic energetic compounds and their salts as high energy-density dangerous compounds:A study of structural variables

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Defence Technology（防务技术） 2024年第9期39卷 15-22页

作者： Mohammad Hossein keshavarz Sedigheh Heydari Bani reza Bakhtiari Seyyed Hesamodin Hosseini Faculty of Applied Sciences Malek Ashtar University of TechnologyIsfahan 177415875Iran

Nitrogen-rich heterocyclic energetic compounds(NRHECs)and their salts have witnessed widespread synthesis in recent *** substantial energy-density content within these compounds can lead to potentially dangerous explosive reactions when subjected to external stimuli such as electrical ***,developing a reliable model for predicting their electrostatic discharge sensitivity(ESD)becomes *** study proposes a novel and straightforward model based on the presence of specific groups(-NH_(2) or-NH-,-N=N^(+)-O^(-)and-NNO_(2),-ONO_(2) or-NO_(2))under certain conditions to assess the ESD of NRHECs and their salts,employing interpretable structural *** a comprehensive dataset comprising 54 ESD measurements of NRHECs and their salts,divided into 49/5 training/test sets,the model achieves promising *** Root Mean Square Error(RMSE),Mean Absolute Error(MAE),and Maximum Error for the training set are reported as 0.16 J,0.12 J,and 0.5 J,***,the ratios RMSE(training)/RMSE(test),MAE(training)/MAE(test),and Max Error(training)/Max Error(test)are all greater than 1.0,indicating the robust predictive capabilities of the *** presented model demonstrates its efficacy in providing a reliable assessment of ESD for the targeted NRHECs and their salts,without the need for intricate computer codes or expert involvement.

关键词： Electrostatic discharge sensitivity Heterocyclic energetic compounds containing azole compound Interpretable structural parameter Safety

Design of Tunable Devices at Terahertz Frequencies Based on Quasi-Photonic Crystals Incorporated with Graphene

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Communications in Theoretical Physics 2019年第10期71卷 1227-1235页

作者： reza Ghayoor Alireza keshavarz Department of Physics Shiraz University of Technology

In this study, we present a new theoretical model including Thue-Morse and double-period sequences as quasi-photonic crystals are incorporation with graphene and investigate the transmission properties of the THz waves in both structures using a straightforward computational method. We also consider properties of nonlinear conductivity in addition to surface linear conductivity for graphene. We observe the sharp peaks and proper forbidden bands are created in the range of 0.3 THz to 30 THz. In addition, we find that by considering the nonlinear term of graphene and engineering the structural parameters such as the chemical potential of graphene, number of layers and the incidence wave angle, transmission levels of peaks enhance scientifically and quality factor improve considerably. These results show that it would be possible to design of high-Q tunable filters with multi-stop bands in the THz regime which can reduce the noise associated with THz frequency peaks and increase the number of sharp frequency peaks.

关键词： graphene nonlinear conductivity terahertz filters transfer matrix transmission spectrum

Modelling the Iranian Petroleum Contract fiscal regime using bargaining game theory to guide contract negotiators

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Petroleum Science 2021年第6期18卷 1887-1898页

作者： Mehdi keshavarz Hossein Iranmanesh reza Dehghan School of Industrial Engineering College of EngineeringUniversity of TehranP.O.Box:11155/4563TehranIran Faculty of Civil Engineering Science and Research BranchIslamic Azad UniversityTehranIran

Based on Iran's sixth development plan,the country's oil and gas industry requires an investment of about$200 bn in the next five years to increase *** Iranian government,to attract and motivate international oil company investment in their oil and gas fields,has presented a new type of risk service contract:the Iranian Petroleum Contract(IPC).This paper summarizes the features of the IPC and presents mathematical models of its fiscal regime for the benefit and guidance of both the National Iranian Oil Company(NIOC)and the ***,adopting bargaining game theory provides a mathematical model for reaching a win-win situation between the NIOC and the ***,a numerical example is given and a sensitivity analysis performed to illustrate the implementation of the proposed *** contractor and the NIOC may use these models when preparing their proposal and in the course of actual negotiations to calculate their internal rate of return,remuneration fee,and net present value for developing the fields at different conditions of their bargaining power,and derive a logical bargain to protect their best possible interests.

关键词： Iranian petroleum contract Fiscal regime Internal rate of return Bargaining game theory

Cyclam Modified Carbon Paste Electrode as a Potentiometric Sensor For Determination of Cobalt(Ⅱ) Ions

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Chemical Research in Chinese Universities 2005年第1期21卷 28-31页

作者： Hamid reza POURETEDAL Mohammad Hossein keshavarz Chemistry Department Malek-ashtar University of Technology Shahin-shahr P. O. Box 83154/115 IranChemistry Department Malek-ashtar University of Technology Shahin-shahr P. O. Box 83154/115 Iran

A new modified carbon paste electrode based on cyclam as a modifier was prepared for the determination of Co(Ⅱ) ions. The proposed electrode shows a Nernstian slope 28.4 mV per decade over a wide concentration range 5.0×10 -6_1.0×10 -1 mol/L of Co 2+ ions with detection limit 2.5×10 -6 mol/L. The sensor exhibits good selectivities for Co 2+ over a wide variety of other cations. It can be used as an indicator electrode in potentiometric titration of cobalt(Ⅱ) ions as well as in direct determination of cobalt(Ⅱ) ions in wastewater of acidic cobalt electroplating bath. The electrode shows Nernestian behavior in a solution of 25% ethanol.

关键词： Carbon paste electrode Cyclam Potentiometry Cobalt

Investigation of bubble diameter and flow regime between water and dilute aqueous ethanol solutions in an airlift reactor

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Frontiers of Chemical Science and Engineering 2011年第2期5卷 194-202页

作者： Baharak SAJJADI Mostafa keshavarz MORAVEJI reza DAVARNEJAD Department of Chemical Engineering Faculty of EngineeringArak UniversityArak 38156-8-8349Iran

In this study,the effect of ethanol addition into pure water and its concentration on bubble diameter,gas hold-up andﬂow regimes were investigated in an airlift *** and water with ethanol(concentration ranging from 0%–1%,v/v)were as dispersed and continuous phases,***ﬁcial gas velocity was consid-ered as an effective *** size distribution was measured by photography and picture analysis at various concentrations of ethanol and various velocities of *** concentration enhancement caused bubble dia-meter to ***,the bubbles diameter in pure water was nearly 4 times higher than that of ethanol with concentration of 1%(v/v)and also was 3.4 times higher than that of ethanol with concentration of 0.25%(v/v)at the highest aeration gas velocity *** ethanol solutions in lower superﬁcial gas velocity,a homogenousﬂow regime was *** trend continued to inlet gas velocity of about 0.4 cm/*** transitionﬂow regime occurred after this datum although in pure water,a homogenousﬂow regime was observed up to a superﬁcial gas velocity of 0.7 cm/*** gas hold-up in dilute ethanol solutions were more than(around 2 times)that of pure water and increased with increasing concentration of ethanol in those solutions.

关键词： airlift rector bubble diameter gas hold-up ﬂow regime ethanol

Prediction of malaria cases in the southeastern Iran using climatic variables:An 18-year SARIMA time series analysis

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Asian Pacific Journal of Tropical Medicine 2021年第10期14卷 463-471页

作者： Hamid reza Tohidinik Hossein keshavarz Mehdi Mohebali Mandana Sanjar Gholamreza Hassanpour HIV/STI Surveillance Research Center and WHO Collaborating Center for HIV SurveillanceInstitute for Futures Studies in HealthKerman University of Medical SciencesKermanIran Center for Research of Endemic Parasites of Iran(CREPI) Tehran University of Medical SciencesTehranIran Department of Medical Parasitology&Mycology School of Public HealthTehran University of Medical SciencesTehranIran

Objective:To predict future trends in the incidence of malaria cases in the southeast of Iran as the most important area of malaria using Seasonal Autoregressive Integrated Moving Average(SARIMA)model,and to check the effect of meteorological variables on the disease ***:SARIMA method was applied to fit a model on malaria incidence from April 2001 to March 2018 in Sistan and Baluchistan province in southeastern *** variables such as temperature,rainfall,rainy days,humidity,sunny hours and wind speed were also included in the multivariable model as ***,the best fitted model was adopted to predict the number of malaria cases for the next 12 ***:The best-fitted univariate model for the prediction of malaria in the southeast of Iran was SARIMA(1,0,0)(1,1,1)12[Akaike Information Criterion(AIC)=307.4,validation root mean square error(RMSE)=0.43].The occurrence of malaria in a given month was mostly related to the number of cases occurring in the previous 1(p=1)and 12(P=1)*** inverse number of rainy days with 8-month lag(β=0.3292)and temperature with 3-month lag(β=-0.0026)were the best predictors that could improve the predictive performance of the univariate ***,SARIMA(1,0,0)(1,1,1)12 including mean temperature with a 3-month lag(validation RMSE=0.414)was selected as the final multivariable ***:The number of malaria cases in a given month can be predicted by the number of cases in the prior 1 and 12 *** number of rainy days with an 8-month lag and temperature with a 3-month lag can improve the predictive power of the model.

关键词： Malaria Time series SARIMA Forecasting Climate Iran

Hydrodynamics and Mass Transfer of Oily Micro-emulsions in An External Loop Airlift Reactor

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Chinese Journal of Chemical Engineering 2014年第3期22卷 267-273页

作者： Mona Ebrahimi Fakhari Mostafa keshavarz Moraveji reza Davarnejad Department of Chemical Engineering Faculty of Engineering Arak University Department of Chemical Engineering Amirkabir University of Technology (Tehran Polytechnic) 424 Hafez Avenue

This study reports an experimental investigation on hydrodynamics and mass transfer characteristics in a 15.6x10-3 m3 external loop airlift reactor for oil-in-water micro-emulsions with oil to water volume ratio （φ） rang- ing from 3% to 7% （by volume）. For comparative purposes, experiments were also carried out with water. Increase in φ of micro-emulsion systems results in an increment in the gas holdup and a decrease in the volumetric gas-liquid oxygen transfer coefficient and liquid circulation velocity, attributed to the escalation in the viscosity of mi- cro-emulsions. The gas holdup and volumetric mass transfer coefficient for micro-emulsion systems are signifi- cantly higher than that of water system. Two correlations are developed to predict the gas holdup and oxygen trans- fer coefficient

关键词： external loop airlitt reactor laydroclynarmcs micro-emulsions oxygen transter

多孔纳米结构Fe/Pt-Fe电极对碱性介质中甲醇电氧化的催化活性（英文）

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催化学报 2015年第7期36卷 1029-1034页

作者： Javad Hosseini Mehdi Abdolmaleki Hamid reza Pouretedal Mohammad Hossein keshavarz Department of Chemistry Malek-ashtar University of Technology Faculty of Science Department of ChemistrySayyed Jamaleddin Asadabadi University

An electrochemical approach to fabricate a nanostructured Fe/Pt-Fe catalyst through electrodeposition followed by galvanic replacement is presented. An Fe/Pt-Fe nanostructured electrode was prepared by deposition of Fe-Zn onto a Fe electrode surface, followed by replacement of the Zn by Pt at open-circuit potential in a Pt-containing alkaline solution. Scanning electron microscopy and energy-dispersive X-ray techniques reveal that the Fe/Pt-Fe electrode is porous and contains Pt. The electrocatalytic activity of the Fe/Pt-Fe electrode for oxidation of methanol was examined by cyclic voltammetry and chronoamperometry. The electrooxidation current on the Fe/Pt-Fe catalyst is much higher than that on flat Pt and smooth Fe catalysts. The onset potential and peak potential on the Fe/Pt-Fe catalyst are more negative than those on flat Pt and smooth Fe electrodes for methanol electrooxidation. All results show that this nanostructured Fe/Pt-Fe electrode is very attractive for integrated fuel cell applications in alkaline media.

关键词：电催化活性甲醇氧化纳米铁碱性介质铂电极多孔 Fe催化剂扫描电子显微镜