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Chitosan/polyethylene glycol impregnated activated carbons： Synthesis, characteriza.ion and adsorption performance

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Frontiers of Chemical Science and Engineering 2017年第4期11卷 575-585页

作者： Ehsan Salehi Fereshteh Soroush Maryam momeni Aboulfazl Bara.i a.i Khakpour . Department of Chemical Engineering Faculty of Engineering Arak University Arak 38156-8-8349 Iran.. Department of Electrical Engineering Faculty of Engineering Arak University Arak 38156-8-8349 Iran.. Arian Fan Azma Company Tehran Iran

Novel modified activated carbons （ACs） with enhanced adsorptive properties were obtained coa.ing by chitosan （CS）, polyethylene glycol （PEG） and blends of the two polymers （0：1, 1：0, 1：1, 1：2 and 2：1 wt/wt） on ACs by an impregna.ion technique. The adsorption perfor- mances of the pristine, a.idified and polymer-impregnated ACs were studied using methylene blue as a model adsorbate. The adsorbents were characterized using Four- ier transform infrared spectroscopy, scanning electron microscopy and abra.ion hardness tests. The average coa.ing thicknesses were between 10 to 23 microns. The pore sizes, pore densities and pore capa.ities of the activated carbons increased as the wt-% PEG in the coa.ing increased. The highest adsorption capa.ity （424.7 mg/g） was obtained for the chitosan-coated ACs and this adsorption was well described by the Langmuir isotherm model. The kinetic results were best described by the pseudo-second-order kinetic model. The highest rate constant was obtained with the ACs modified with the CS：PEG （2：1） coa.ing and this result was almost 2.6 times greater than that of the unmodified ACs. The CS/PEG impregnated ACs also displayed superior hardness （-90%）, compared to unmodified ACs （-85%）. Overall the chitosan had a greater effect on improving adsorption capa.ity whereas the polyethylene glycol enhanced the adsorption rate.

关键词： carbon biocomposites impregna.ion chito-san polyethylene glycol image processing

Novel Hybrid X GBoost Model to Forecast Soil Shear Strength Based on Some Soil index Tests

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Computer Modeling in Engineering & Sciences 2023年第9期136卷 2527-2550页

作者： Ehsan momeni Biao He Ya.in Abdi Da.ial Jahed Armagha.i Department of Civil Engineering Faculty of EngineeringLorestan UniversityKhorramabad***Iran Department of Civil Engineering Faculty of EngineeringUniversiti MalayaKuala Lumpur50603Malaysia Department of Geology Faculty of SciencesLorestan UniversityKhorramabad***Iran Department of Urban Planning Engineering Networks and SystemsInstitute of Architecture and ConstructionSouth Ural State UniversityChelyabinsk454080Russia

When building geotechnical constructions like retaining walls and dams is of interest,one of the most important factors to consider is the soil’s shear strength *** study makes an effort to propose a novel predictive model of shear *** study implements an extreme gra.ient boosting(XGBoost)technique coupled with a powerful optimiza.ion algorithm,the salp swarm algorithm(SSA),to predict the shear strength of va.ious *** do this,a database consisting of 152 sets of data.is prepared where the shear strength(τ)of the soil is considered as the model output and some soil index tests(e.g.,dry unit weight,water content,and plasticity index)are set as model *** is designed and tuned using both effective parameters of XGBoost and SSA,and themost accuratemodel is introduced in this *** theSSA-XGBoostmodel is assessedbased on the coefficient of determina.ion(R2)and va.iance account for(VAF).Overall,the obtained values of R^(2) and VAF(0.977 and 0.849)and(97.714%and 84.936%)for training and testing sets,respectively,confirm the worka.ility of the developed model in forecasting the soil shear *** investigate the model genera.iza.ion,the prediction performance of the model is tested for another 30 sets of data(va.ida.ion data).The va.ida.ion results(e.g.,R^(2) of 0.805)suggest the worka.ility of the proposed ***,findings suggest that when the shear strength of the soil cannot be determined directly,the proposed hybrid XGBoost-SSA model can be utilized to assess this parameter.

关键词： Predictive model salp swarm algorithm soil index tests soil shear strength XGBoost

Effects of Hydro-alcoholic Extract of Launaea acanthodes on Serum Gonadotropin and Testosterone Levels and the Structure of Seminiferous Tubules in Hyperglycemic Rats

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Chinese Journal of integra.ive Medicine 2016年第3期22卷 207-213页

作者： Ameneh Mohamma.i Morteza Behnam-Rassouli Zeinab momeni Naser Mahda.i-Shahri Department of Biology Faculty of ScienceFredowsi University of Mashhad

Objective： To investigate the effects of hydro-alcoholic extract of Launaea acanthodes, a blood glucose lowering plant in folk medicine of iran, on the structure of seminiferous tubules and serum gonadotropin and testosterone levels in hyperglycemic rats. Methods： Twenty-four Wistar rats were randomly allocated into 4 groups （n=6）： control, streptozotocin （STZ）, STZ ＋ insulin [STZ ＋ ins, 5 iU/（kg·day）], and STZ ＋ Launaea acanthodes extract [STZ ＋ Ext, 150 mg/（kg·day）]. Blood samples were collected at the 2nd and 4th weeks for detection of testosterone, follicle stimula.ing hormone （FSH） and luteinizing hormone （LH） with enzyme-linked immuno sorbent assay （ELiSA）, and the dght testes of rats were removed at the 7th week for the evalua.ion of diameter and wall thickness of seminiferous tubules and number of Leydig cells using unbiased stereological techniques. Results： in compa.ison with the control group, at the 2nd week FSH （0.45 vs 0.03, 0.02, 0.02 lUlL in STZ, STZ ＋ ins and STZ ＋ Ext groups, respectively） and LH （1.02 vs 0.37, 0.2, 0.29 iU/L） showed significant decreases （all P〈0.05） and testosterone （4.2 vs 8.37, 7.78, 11.8 ng/mL） showed a remarkable increase （all P〈0.05）. The levels of these hormones became closer in the STZ ＋ Ext and the STZ ＋ ins groups to the control at the 4th week. A significant decrease in diameter and wall thickness of seminiferous tubules and number of Leydig cells were observed in the STZ group as compared with the control （P〈0.01）. Conclusions： Administra.ion of Launaea extract demonstrated a beneficial impact on the protection of testis from pathogenic and degenera.ive effects of hyperglycemia which may be partly due to its potential antioxida.ive effects.

关键词： hyperglycemia Launaea acanthodes testis gonadotropins testosterone rat

Tribological beha.ior of ZK60Gd alloy reinforced by SiC particles after precipita.ion hardening

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Journal of Magnesium and Alloys 2023年第9期11卷 3362-3381页

作者： Ehsan momeni Hassan Sha.ifi Morteza Tayebi Ahmad Keyva.i Ermia Aghaie Yashar Behna.ian Department of Materials Science and Engineering University of ShahrekordIran Young Researchers and Elites Club Science and Research BranchIslamic Azad UniversityTehranIran Department of Chemical and Materials Engineering University of AlbertaEdmontonAlberta T6G 1H9Canada

in this research, the effect of precipita.ion hardening on the tribological beha.ior of the ZK60Gd/SiC composite was studied. For this purpose, ZK60Gd alloy containing with 5 and 10 wt% SiC were produced with stir casting method. The microstructure characteriza.ion of the samples showed the wide distributions of Mg_(7)Zn_(3) and Gd(Mg_(0.5)Zn_(0.5)) precipitates were formed during casting. The results of hardness measurement after precipita.ion hardening at different temperatures showed that the hardness peck was obtained at 175 ℃. The wear tests with different loads(10, 40, 60, 90, and 120 N) and velocities(0.1, 0.3, 0.6, and 0.9 m/s) were performed on the as-cast and heat treated sample at 125, 175, and 225 for 12 h. Between the different precipita.ion hardening conditions, the precipita.ion hardened samples at 175 ℃ had the highest hardness values and least wear rate. The sample containing 10% reinforcement had the least wear rate between the unreinforced alloy and the composites. The results showed that abra.ive, adhesive, dela.ina.ion, MML, and fa.igue wear mecha.isms were the dominant wear mecha.isms for the composite samples. in contrast, the dominant wear mecha.ism for the unreinforced samples was abra.ive, adhesive,dela.ina.ion, MML, and plastic deforma.ion.

关键词： Precipita.ion hardening Composite Gadolinium Mg-Zn-Zr-Gd Wear map

Dyna.ic Recrystalliza.ion Beha.ior of 13%Cr Martensitic Stainless Steel under Hot Working Condition

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Journal of Materials Science & Technology 2012年第5期28卷 467-473页

作者： G.R.Ebra.imi H.Keshmiri A.R.Maldar A.momeni Metallurgical and Materials Engineering Department Ferdowsi University of MashhadMashhad ***Iran Department of Materials Engineering Sabzevar Tarbiat Moallem UniversitySabzevar ***Iran Materials Science and Engineering Department Hamedan University of TechnologyHamedan ***Iran

in this study,the effect of hot deforma.ion on martensitic stainless steel was carried out in temperatures between 950 to 1100℃ and strain rates of 0.001,0.01 and 0.1 s *** important dyna.ic recrystalliza.ion parameters,the critical strain and the point of ma.imum dyna.ic softening,were derived from strain hardening rate vs stress *** the calculated parameters were used to predict the dyna.ic recrystallized *** results show that critical stress and strain increase with decrea.ing deforma.ion temperature and increa.ing strain *** hot deforma.ion activa.ion energy of the steel is also investigated in the present work with 413 kJ/*** experimental flow curves are in fair agreement with the kinetics of dyna.ic recrystalliza.ion model.

关键词： Hot deforma.ion Dyna.ic recrystalliza.ion Critical strain

Microstructural evolution of a superaustenitic stainless steel during a two-step deforma.ion process

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interna.ional Journal of Minerals,Metallurgy and Materials 2018年第2期25卷 181-189页

作者： N.Bayat G.R.Ebra.imi A.momeni H.R.Ezatpour Department of Materials and Polymer Engineering Hakim Sabzevari University Department of Materials Science and Engineering Hamedan University of Technology Faculty of Engineering Sabzevar University of New Technology

Single-and two-step hot compression experiments were carried out on 16Cr25Ni6Mo superaustenitic stainless steel in the temperature range from 950 to 1150°C and at a strain rate of 0.1 s^（-1）. in the two-step tests, the first pass was interrupted at a strain of 0.2; after an interpass time of 5, 20, 40, 60, or 80 s, the test was resumed. The progress of dyna.ic recrystalliza.ion at the interruption strain was less than 10%. The sta.ic softening in the interpass period increased with increa.ing deforma.ion temperature and increa.ing interpass time. The sta.ic recrystalliza.ion was found to be responsible for fast sta.ic softening in the temperature range from 950 to 1050°C. However, the gentle sta.ic softening at 1100 and 1150°C was attributed to the combina.ion of sta.ic and metadyna.ic recrystalliza.ions. The correla.ion between calculated fractional softening and microstructural observa.ions showed that approximately 30% of interpass softening could be attributed to the sta.ic recovery. The microstructural observa.ions illustrated the forma.ion of fine recrystallized grains at the grain bounda.ies at longer interpass time. The Avra.i kinetics equa.ion was used to establish a rela.ionship between the fractional softening and the interpass period. The activa.ion energy for sta.ic softening was determined as 276 kJ/mol.

关键词： superaustenitic stainless steel dyna.ic recrystalliza.ion sta.ic softening metadyna.ic recrystalliza.ion microstructural evolution Avra.i kinetics equa.ion

A low-voltage and energy-efficient full adder cell based on carbon nanotube technology

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Nano-Micro Letters 2010年第2期2卷 114-120页

作者： Keivan Na.i Rabe'e Sha.ifi Rad Mohammad Hossein Moaiyeri a.ir momeni Faculty of Electrical and Computer Engineering Shahid Beheshti UniversityGC

Sca.ing problems and limita.ions of conventional silicon transistors have led the designers to exploit novel nano-technologies. One of the most promising and fea.ible nano-technologies is CNT(Carbon Nanotube) based transistors. in this paper, a high-speed and energy-efficient CNFET(Carbon Nanotube Field Effect Transistor) based Full Adder cell is proposed for nanotechnology. This design is simulated in va.ious supply voltages, frequencies and load capa.itors using HSPiCE circuit simulator. Significant improvement is achieved in terms of speed and PDP(Power-Delay-Product) in compa.ison with other classical and state-of-the-art CMOS and CNFET-based designs, existing in the literature. The proposed Full Adder can also drive large load capa.itance and works properly in low supply voltages.

关键词： CNFET Low-Voltage Full-Adder Minority-Function Nanotechnology

A Compara.ive Study of the Electronic and Magnetic Properties of Gd_5Ge_4 and Gd_5Si_4 Compounds

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Communica.ions in Theoretical Physics 2014年第12期61卷 903-908页

作者： Z.momeni La.imi A.a.iraba.izadeh A.Yazda.i H.Ara.i Department of Physics Faculty of Science University of Birjand P.O.Box 97175-615 Birjand Iran Tarbiat Modares University Tehran P.O.Box 14115-175 Iran Department of Physics Faculty of Basic Science Ferdowsi University Mashhad Iran

We present a compara.ive study of electronic structure and magnetic properties of Gd5Si4 and Gd5Ge4compounds using first principles full potential linea.ized augmented plane wave(FP-LAPW) method based on density functional theory(DFT) using the WiEN2 k code. The local-spin density approxima.ion with correla.ion energy(LSDA+U) method has been used as the exchange-correla.ion potential. The optimized lattice constants are in good agreement with the experimental data. The total and partial density of states(DOS) of Gd5Si4 and Gd5Ge4show the difference in Si 3p-Gd 5d and Ge 4p-Gd 5d hybridiza.ion, which have an effective role in indirect exchange *** addition, the magnetic moments of Gd, Si, and Ge atoms and the compounds are calculated to cla.ify the differences in the magnetic properties of these compounds.

关键词： magnetocaloric compound density functional theory electronic and magnetic properties exchange interaction

Adenoviral gene therapy in gastric cancer: A review

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World Journal of Gastroenterology 2008年第2期14卷 180-184页

作者： Nima Kha.ighinejad Hesammodin Ha.iri Omid Behnamfar Arash Yousefi a.ir momeni isfahan University of Medical Sciences Khalighinejad Nima Number 111 5th street Mardavij Street Isfahan Iran

Gastric cancer is one of the most common ma.ignancies worldwide. With current therapeutic approaches the prognosis of gastric cancer is very poor, as gastric cancer accounts for the second most common cause of death in cancer related deaths. Gastric cancer like almost all other cancers has a molecular genetic ba.is which relies on disruption in normal cellular regulatory mecha.isms regarding cell growth, apoptosis and cell division. Thus novel therapeutic approaches such as gene therapy promise to become the alterna.ive choice of treatment in gastric cancer. in gene therapy, suicide genes, tumor suppressor genes and anti-angiogenesis genes among many others are introduced to cancer cells via vectors. Some of the vectors widely used in gene therapy are Adenoviral vectors. This review provides an update of the new developments in adenoviral cancer gene therapy including strategies for inducing apoptosis, inhibiting metasta.is and targeting the cancer cells.

关键词： Gastric cancer Adenovirus Gene therapy Vector Apoptosis Metasta.is