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Effects of operating parameters on oxidative coupling of methane over Na-W-Mn/SiO_2 catalyst at elevated pressures

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Journal of Natural Gas Chemistry 2011年第2期20卷 204-213页

作者： Jafar Sadeghzadeh Ahari mohammad taghi sadeghi Saeed Zarrinpashne Process Simulation and Control Laboratory Chemical Engineering College Iran University of Science and Technology (IUST) Gas Research Division-Research Institute of Petroleum Industry (RIPI)

The effects of operating parameters on oxidative coupling of methane （OCM） over Na-W-Mn/SiO2 catalyst have been studied at elevated pressures of 0.2, 0.3 and 0.4 MPa under low gaseous hourly space velocity （GHSV） and low temperature conditions. Experimental results show that when the operating pressure is increased, C2＋ yield slightly decreases, while the maximum ratio of ethylene to ethane remains unchanged. Moreover, it has been found empirically that increase of pressure does not affect the catalyst behavior permanently, the catalyst recovers its original low pressure performance without hysteresis behavior by reducing the pressure. Under the investigated conditions, when oxygen is completely consumed, the increase of GHSV leads to improvement in C2 selectivity, while C3＋ and COx selectivities decrease slightly. The C2＋ selectivity increases by increase of nitrogen diluent in the feed, but the C3＋ hydrocarbons selectivities decrease with increase of nitrogen since it is possible that further dilution at high pressure may reduce the probability of collision between CH3 and C2＋ hydrocarbons. During the stability test at high pressure, the catalyst performance remains unchanged throughout the 20 h running. The fresh and used catalysts were characterized using XRD, SEM and N2 adsorption-desorption methods. It was found that the phase transformation of the support from α-cristobalite to tridymite and quartz does not have obvious effect on catalyst performance at high pressure.

关键词： operating parameters oxidative coupling of methane Na-W-Mn/SiO2 catalyst elevated pressure

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：加氢脱硫工艺支持向量回归 PCA 传感器设计 WT 预测精度多元线性回归主成分分析

Improvement of the prediction performance of a soft sensor model based on support vector regression for production of ultra-low sulfur diesel

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Petroleum Science 2015年第1期12卷 177-188页

作者： Saeid Shokri mohammad taghi sadeghi Mahdi Ahmadi Marvast Shankar Narasimhan Department of Chemical Engineering Iran University of Science and Technology (IUST) Process and Equipment Technology Development Division Research Institute of Petroleum Industry (RIPI) Department of Chemical Engineering

A novel data-driven, soft sensor based on support vector regression （SVR） integrated with a data compression technique was developed to predict the product quality for the hydrodesulfurization （HDS） process. A wide range of experimental data was taken from a HDS setup to train and test the SVR model. Hyper-parameter tuning is one of the main challenges to improve predictive accuracy of the SVR model. Therefore, a hybrid approach using a combination of genetic algorithm （GA） and sequential quadratic programming （SQP） methods （GA-SQP） was developed. Performance of different optimization algorithms including GA-SQP, GA, pattern search （PS）, and grid search （GS） indicated that the best average absolute relative error （AARE）, squared correlation coefficient （R2）, and computation time （CT）（AARE = 0.0745, R2 = 0.997 and CT = 56 s） was accomplished by the hybrid algorithm. Moreover, to reduce the CT and improve the accuracy of the SVR model, the vector quantization （VQ） technique was used. The results also showed that the VQ technique can decrease the training time and improve prediction performance of the SVR model. The proposed method can provide a robust, soft sensor in a wide range of sulfur contents with good accuracy.

关键词： Soft sensor Support vector regression Hybrid optimization method Vector quantization Petroleum refinery Hydrodesulfurization process Gas oil

LaZn_xFe_(1-x)O_3钙钛矿型纳米催化剂的制备、表征及其甲苯燃烧性能(英文)

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催化学报 2010年第7期31卷 747-750页

作者： Seyed Ali HOSSEINI mohammad taghi sadeghi Abdolali ALEMI Aligholi NIAEI Dariush SALARI Leila KAFI-AHMADI Department of Applied Chemistry Faculty of ChemistryUniversity of Tabriz Department of Inorganic Chemistry Faculty of ChemistryUniversity of Tabriz

Nanostructured LaFeO3 and substituted LaZnxFe1-xO3(x = 0.01,0.05,0.1,0.2,and 0.3) perovskites were synthesized by the sol-gel auto-combustion method and used in the catalytic combustion of *** structures and surface properties were investigated by X-ray diffraction,Fourier transmission infrared spectroscopy,BET surface area,and scanning electron *** data revealed that the total insertion of zinc into LaFeO3 takes place when x ≤ ***,ZnO segregation occurs to some extent,especially at x > *** performance of these perovskites was evaluated by toluene *** catalytic activity of the catalysts increased substantially with an increase in zinc *** results can be attributed to the cooperative effect between LaZnxFe1-xO3 and the zinc oxide *** relative concentration of these phases determines their oxygen activation ability and reactivity.

关键词： sol-gel auto-combustion perovskite toluene catalytic oxidation LaZnxFe1-xO3

纳米晶La_(1-x)Eu_xFeO_3的合成、表征及催化甲苯燃烧反应活性(英文)

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催化学报 2011年第9期32卷 1465-1468页

作者： Seyed Ali HOSSEINI mohammad taghi sadeghi-SORKHANI Leila KAFI-AHMADI Abdolali ALEMI Aligholi NIAEI Dariush SALARI Department of Applied Chemistry Faculty of Chemistry University of Tabriz Department of Inorganic Chemistry Faculty of Chemistry University of Tabriz

Nanostructured LaFeO3 and substituted La1-xEuxFeO3 (x = 0.1, 0.15, and 0.2) perovskites were synthesized by sol-gel auto-combustion and their activities during the combustion of toluene were evaluated. The structure and physico-chemical properties of the perovskites were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and BET surface area analyses. The compounds were crystallized as a perovskite phase with an orthorhombic structure. The mean particle size of the perovskites increased with an increase in europium loading while the specific surface area decreased. Characterization data confirmed that a total insertion of Eu into LaFeO3 occurred at x ≤ 0.15. However, Eu2O3 segregation occurred to some extent especially at x >0.15. The catalytic activity of the catalysts increased substantially with an increase in Eu substitution in the evaluated range.

关键词： perovskite sol-gel europium volatile organic compounds catalytic oxidation

The effect of celastrol in combination with 5-fluorouracil on proliferation and apoptosis of gastric cancer cell lines

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Oncology Research 2024年第7期32卷 1231-1237页

作者： mohammad-taghi MORADI DHIYA ALTEMEMY MAJID ASADI-SAMANI PEGAH KHOSRAVIAN MARZIYEH SOLTANI LEILA HASHEMI AZADEH SAMIEI-SEFAT Medical Plants Research Center Basic Health Sciences InstituteShahrekord University of Medical SciencesShahrekordIran Department of Pharmaceutics College of PharmacyAl-Zahraa University for WomenKarbalaIraq Cellular and Molecular Research Center Basic Health Sciences InstituteShahrekord University of Medical SciencesShahrekordIran

Background:Despite the availability of chemotherapy drugs such as 5-ﬂuorouracil(5-FU),the treatment of some cancers such as gastric cancer remains challenging due to drug resistance and side *** study aimed to investigate the effect of celastrol in combination with the chemotherapy drug 5-FU on proliferation and induction of apoptosis in human gastric cancer cell lines(AGS and EPG85-257).Materials and Methods:In this in vitro study,AGS and EPG85-257 cells were treated with different concentrations of celastrol,5-FU,and their *** proliferation was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT)*** synergistic effect of 5-FU and celastrol was studied using Compusyn *** DNA content at different phases of the cell cycle and apoptosis rate was measured usingﬂow ***:Co-treatment with low concentrations(10%inhibitory concentration(IC10))of celastrol and 5-FU signiﬁcantly reduced IC50(p<0.05)so that 48 h after treatment,IC50 was calculated at 3.77 and 6.9μM for celastrol,20.7 and 11.6μM for 5-FU,and 5.03 and 4.57μM for their combination for AGS and EPG85-257 cells,*** mean percentage of apoptosis for AGS cells treated with celastrol,5-FU,and their combination was obtained 23.9,41.2,and 61.9,and for EPG85-257 cells 5.65,46.9,and 55.7,*** addition,the 5-FU and celastrol-5-FU combination induced cell cycle arrest in the synthesis ***:Although celastrol could decrease the concentration of 5-ﬂuorouracil that sufﬁced to suppress gastric cancer cells,additional studies are required to arrive at conclusive evidence on the anticancer effects of celastrol.

关键词： Gastric cancer Celastrol Terpenoid Cell cycle regulation Apoptosis Synergism

Mechanical properties and microstructural evolution of rheocast A356 semi-solid slurry prepared by annular electromagnetic stirring

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China Foundry 2023年第4期20卷 315-328页

作者： mohammad taghi Asadi Khanouki Department of Materials and Metallurgy Engineering Shahid Bahonar University of KermanP.O.Box ***KermanIran Mineral Industries Research Center(MIRC) Shahid Bahonar University of KermanP.O.Box ***KermanIran

Nowadays,having an effective technique in preparing semi-solid slurries for rheocasting process seems to be an essential *** this study,semi-solid slurry of A356 aluminum alloy was prepared by three-phase annular electromagnetic stirring(A-EMS)technique under different *** effects of stirring current,pouring temperature and stirring time on microstructural evolution,mean particle size,shape factor and solid fraction were *** rheocasting process was carried out by using a drop weight setup and to inject the prepared semi-solid slurry in optimal conditions into the step-die *** filling behavior and mechanical properties of parts were *** evolution showed that the best semi-solid slurry which had fine spherical particles with the average size of~27μm and a shape factor of~0.8 was achieved at the stirring current of 70 A,melt pouring temperature of 670℃,and stirring time of 30 *** these conditions,the step-die cavity was completely filled at die preheating temperature of 470℃.The hardness increases by decreasing step thickness as well as die preheating ***,the tensile properties are improved at lower die preheating *** fracture surface,which consists of a complex topography,indicates a typical ductile fracture.

关键词： semi-solid slurry annular electromagnetic stirring rheocast A356 aluminum alloy microstructural evolution mechanical properties magnetic flux density

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

Identification of Urban Worn-Out Textures and Prioritization of Organizing Strategies through Remote Sensing Performance and BWM Method Combination:(A Case Study: Zanjan City)

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Chinese Journal of Urban and Environmental Studies 2023年第4期11卷 100-127页

作者： Mohsen AHADNEJAD REVESHTY mohammad taghi HEYDARI mohammad RASOOLI Geography and Urban Planning Department of Geography University of Zanjan

The growing trend of urban population has led to an increase in worn-out urban textures. Although various policies have been proposed to organize these textures, past data such as detailed and comprehensive plans in Iranian cities have afforded to achieve desirable results. For this purpose,Landsat satellite images taken on December 8, 2019 were used. Hence, this study tried to provide the latest method of information on urban worn-out textures with a new method and identify areas prone to becoming dysfunctional textures. For this purpose, Landsat 8 satellite images(December 2020) have been used. In this regard, in order to analyze the ENVI environment, two methods have been used:(1) The command of emissivity;(2) the calculation of the normalized and emissive vegetation cover index NDVI(Esfandiari, Darabad Fariba, Raoof Mostafazadeh, Amirhesam Pasban, and Behruoz Nezafat Takleh. 2022. “Integrating Terrain and Vegetation Indices to Estimate and Identify the Soil Erosion Risk Amoughin Watershed, Ardabil.” Journal of Spatial Analysis and Environmental Hazarts, 9(1): 77–96.) represents the reflection of solar energy from the earth's surface, which indicates the types of vegetation conditions. To calculate the temperature of the city surface, LST(earth surface temperature in remote sensing refers to the heat measured by a radiometer in a momentary field of view)(Pirnazar et al., 2018). as well as to express the consequences of worn-out textures from the Driving forces-Pressure-State Impact-Response(DPSIR) model. Also, the best–worst method(BWM) is one of the newest and most effective multicriteria decision-making techniques, which is used to weigh the factors and decision criteria and determine the priority of decisions(sadeghi Darvaze et al., 2019) has been used to express the preference of the solutions for the organization of worn-out textures. Finally, the geographic information system(GIS) which refers to a set of hardware, software, geographic data and human resour

关键词： Remote sensing urban worn-out textures Zanjan city BWM