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Ion separation and water purification by applying external electric field on porous graphene membrane

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Nano Research 2018年第4期11卷 2229-2236页

作者： Amir Lohrasebi samaneh Rikhtehgaran Department of Physics University of Isfahan Isfahan 81746-73441 Iran School of Nano Science Institute for Research in Fundamental Sciences (IPM) Tehran 19395-5531 Iran Department of Physics Florida Atlantic University 777 Glades Road Boca Raton FL 33431-0991 USA

Using molecular dynamics （MD） simulations, a porous graphene membrane was exposed to external electric fields to separate positive and negative ions from salt-water and to produce fresh water. It was observed that, by increasing the strength of the applied electric field, ion separation improved noticeably. In addition, to obtain fresh water, the designed system included two graphene membranes, which are exposed to two external electric fields in opposite directions. Ion rejection was found to be greater than 93% for the electric field of 10 mV/A and higher. This atomic-level simulation increases the understanding of electric field effects on desalination using multilayer graphene membranes and can be helpful in designing more efficient membranes.

关键词： desalination nanoporous graphene membrane ion separation molecular dynamicss imulation electric field

Chemical functionalization of chitosan biopolymer and chitosan-magnetite nanocomposite with sulfonic acid for acid-catalyzed reactions

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Chinese Journal of Chemical Engineering 2021年第11期34卷 154-161页

作者： Majid Masteri-Farahani samaneh Shahsavarifar Research Institute of Green Chemistry Faculty of ChemistryKharazmi UniversityTehranIran

Chemical functionalization of chitosan biopolymer and chitosan-magnetite nanocomposite was performed with sulfonic acid functional groups to achieve new solid acid *** sulfonic acid functional groups were created through the ring opening nucleophilic reaction of amine groups of chitosan with 1,4-butane *** transform infrared spectroscopy(FT-IR)and X-ray photoelectron spectroscopies(XPS)verified the successful sulfonic acid functionalization of *** obtained sulfonic acid functionalized chitosan-magnetite nanocomposite showed superparamagnetic properties according to the vibrating sample magnetometry analysis and exhibited magnetic separation feature from dispersed *** adsorption-desorption analysis indicated the increase in surface area after formation of chitosan-magnetite nanocomposite and functionalization with sulfonic *** of the prepared solid acids exhibited high catalytic activities in the acid-catalyzed acetic acid esterification with n-butanol and benzaldehyde acetalization with ethylene glycol as model ***,they can be reused several times without considerable loss of their activities.

关键词： Chitosan Magnetite Nanostructure Sulfonic acid Catalysis Esterification

A New Highly Sensitive Optical Sensor Based on Congo-Red for the Determination of Thorium(Ⅳ) in Aqueous Solution

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Journal of Analysis and Testing 2023年第4期7卷 416-424页

作者： Abdollah Yari samaneh Penhani Faculty of Chemistry Lorestan UniversityKhorramabad 68151-44316Iran

This essay explores the use of the sol-gel method based on the Congo-red reagent as an effective approach to create an optical sensor for the detection and tracking of Thorium(Ⅳ)(Th^(4+)).Upon exposure to a Th^(4+)-containing solution,the sensor exhibits significant absorption signal change that linearly correlates with Th^(4+)ion concentration across a wide *** is capable of detecting Th^(4+)ion in the linear dynamic range of 1.7×10^(-8)to 1.1×10^(-3)mol/L,with a detection limit of 5.3×10^(-9)mol/*** optode’s exceptional porous network,created through the sol-gel technique,contributes to its commendable performance,reliable repeatability,improved sensitivity,swift response time,and discerning selectivity.

关键词： Congo-red Optical sensor Sol-gel Thorium(IV)

Optimization of hydrothermal synthesis of H-ZSM-5 zeolite for dehydration of methanol to dimethyl ether using full factorial design

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Journal of Natural Gas Chemistry 2012年第3期21卷 344-351页

作者： samaneh Hosseini Majid Taghizadeh Ali Eliassi Chemical Engineering Department Babol University of TechnologyP.O.Box 484*** BabolIran Chemical Technologies Research Department Iranian Research Organization for Science and TechnologyTehranIran

H-ZSM-5 zeolite was synthesized by hydrothermal method. The effects of different synthesis parameters, such as hydrothermal crystallization temperature （170-190 ℃） and Si/A1 molar ratio （100-150）, on the catalytic performance of the dehydration of methanol to dimethyl ether （DME） over the synthesized H-ZSM-5 zeolite were studied. The catalysts were characterized by N2 adsorption-desorption, XRD, NH3-TPD, TGA/DTA, and SEM techniques. The full factorial design of experiments was applied to the synthesis of H-ZSM-5 zeolite and the effects of synthesis conditions and their interaction on the yield of DME as the response variable were determined. Analysis of variance showed that two variables and their interaction significantly affected the response. According to the experimental results, the optimized catalyst prepared at 170℃ with the Si/A1 molar ratio of 100 showed the best catalytic performance among the tested H-ZSM-5 zeolite.

关键词： full factorial design H-ZSM-5 synthesis methanol dehydration dimethyl ether

Performance of passive and reactive profiled median barriers in traffic noise reduction

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第1期12卷 78-86页

作者： Mohammad Reza MONAZZAM samaneh Momen Bellah FARD Occupational Hygiene Department School of Public HealthTehran University of Medical Sciences Department of Environmental Science Graduate School of the Environment and EnergyScience and Research BranchIslamic Azad University

Median noise barriers, like parallel noise barriers, can be employed to reduce the impact of traffic on roadside communities via the direct propagation path. The performance of different shapes of median barriers was compared using reactive and passive surfaces and a 2D boundary element method (BEM). In the case of reactive surfaces, quadratic residue diffusers (QRDs) and primitive root diffusers (PRDs) were used on the top and stem surfaces of median barriers. To introduce passive barriers, two different absorbent materials including fibrous material and a grass surface with flow resistivity of 20 000 and 2500 kg/(s·m2), respectively, were similarly applied. The effect of thin absorptive barriers was similar at lower frequencies and better at mid and high frequencies to that of their equivalent rigid barriers. More improvement was achieved by covering the top surface of thick barriers with grass rather than with fibrous material. The performance of QRD and PRD barriers where the diffuser was located on the top surface was more frequency dependent than that of barriers coated with fibrous material. A comparison of the average A-weighted insertion loss in the thick barriers showed that the greatest improvement (2.59 dB (A)) was achieved using a barrier of 30-cm thickness covered with grass.

关键词： Absorption Quadratic residue diffuser (QRD) Primitive root diffuser (PRD) Noise barrier

Model for increased efficiency of CIGS solar cells by a stepped distribution of carrier density and Ga in the absorber layer

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Science China(Physics,Mechanics & Astronomy) 2013年第8期56卷 1533-1541页

作者： SHARBATI samaneh KESHMIRI Sayyed-Hossein Department of Electrical Engineering Ferdowsi University of Mashhad

In this paper, several structures for multilayer Cu(In1-xGax) Se2 (CIGS) thin film solar cells are proposed to achieve high conversion efficiency. All of the modeling and simulations were based on the actual data of experimentally produced CIGS cells reported in the literature. In standard CIGS cells with a single absorber layer, the effects of acceptor density and Ga content on device performance were studied, and then optimized for maximum conversion efficiency. The same procedure was performed for cells with two and three sectioned CIGS absorber layers in which Cu and/or Ga contents were varied within each consecutive section. This produces an internal additional electric field within the absorber layer, which resulted in an increase in carrier collection for longer wavelength photons, and hence, improvement in the conversion efficiency of the cell. An increase of approximately 3% in efficiency is predicted for cells with two layer absorbers. For multilayer cells in which Cu and Ga distribution were stepped simultaneously, the improvement could be approximately 3.5%. This improvement is due to; enhanced carrier collection for longer-wavelength photons, and reduced recombination at the heterojunction and back regions of the cell. These results are confirmed by the physics of the cells.

关键词： Cu (In Ga)Se2 (CIGS) multilayer thin film solar cell quantum efficiency

Utilizing blockchains in opportunistic networks for integrity and confidentiality

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Blockchain(Research and Applications) 2024年第1期5卷 31-38页

作者： samaneh Rashidibajgan Thomas Hupperich Cyber Security Department of Information SystemsUniversity of Münster80539 MünsterGermany

Opportunistic networks(OppNets)are usually a set of smart,wearable,and portable devices or entities with mobility that connect wirelessly without requiring *** a network is of great importance in data transmission,particularly in incidents and disasters,whether man-made or ***,message integrity and confidentiality are of concern when dealing with vital and physiological data transmission under strict privacy *** this work,we propose a structure to classify messages based on their priority in different ***,due to the decentralized architecture of OppNets,we propose a blockchain-based structure for providing security for high-priority *** contains three sequences of functional blocks with a light and simplified implementation that make it suitable for battery-powered wearable devices that are limited in energy consumption and computational *** simulation results show that by increasing the number of nodes in the network,the average of the changes in block sizes is neglectable,which addresses the computation ***,we analyze the performance of the proposed structure in terms of message delivery and network overhead compared with the Epidemic and Prophet routing *** results indicate advancing the overall performance of the proposed algorithm.

关键词： Opportunistic networks Blockchain Message integrity Message confidentiality

Soil functional indicators in mixed beech forests are clearly species-specifi c

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Journal of Forestry Research 2023年第4期34卷 1033-1049页

作者： Yahya Kooch Neda Ghorbanzadeh samaneh Hajimirzaaghaee Markus Egli Faculty of Natural Resources&Marine Sciences Tarbiat Modares UniversityNoor 46417-76489MazandaranIran Faculty of Natural Resources University of GuilanSowmeh Sara 4432-3136GuilanIran Faculty of Natural Resources University of Agricultural Sciences and Natural ResourcesSariIran Department of Geography University of ZürichZurichSwitzerland

Beech stands are considered part of the ancient forest ecosystems in the northern *** mixed stands in beach forest ecosystems,the type of associated tree species can signifi cantly aff ect soil functions,but their infl uence on microbial activity,nutrient cycling and belowground properties is ***,we considered forest patches in northern Iran that are dominated by diff erent tree species:Fagus orientalis Lipsky,Quercus castaneifolia ***.,Pterocarya fraxinifolia(Lam.),Tilia begonifolia Stev.,Zelkova carpinifolia Dippe,Acer cappadocicum Gled,Acer velutinum Boiss.,Fraxinus excelsior L.,Carpinus betulus L.,and Alnus subcordata *** each forest patch–tree species,litter and soil samples(25×25×10 cm,100 of each)were analyzed for determine soil and litter properties and their relationship with tree *** litter decomposition rate during a 1-year experiment was also determined.A PCA showed a clear diff erence between selected litter and soil characteristics among tree ***,***,***,***,***,***,and *** enhanced soil microbial biomass of carbon,whereas patches with ***,*** and *** had faster litter decomposition and enhanced biotic activities and C and N ***,soil function indicators were species-specifi c in the mixed beech ***(a N-fi xing species),*** and *** were main drivers of microbial activities related to nutrient cycling in the old-growth beech forest.

关键词： Old-growth forest Deciduous tree species Soil fertility Microbial activities Carbon and nitrogen cycle

Synthesis, characterization and antimicrobial activity of alkaline ion-exchanged ZnO/bentonite nanocomposites

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Journal of Central South University 2016年第4期23卷 787-792页

作者： Hamideh Pouraboulghasem Mohammad Ghorbanpour Razieh Shayegh samaneh Lotfiman Department of Food Science Islamic Azad University-Sarab Branch Sarab Iran Chemical Engineering Department University of Mohaghegh Ardabili Ardabil Iran

Nanocomposites of zinc/bentonite clay were synthesized for use as an antibacterial material by a quick and simple alkaline ion exchange method. The synthesis of zinc doped bentonite nanocomposite was accomplished by placing bentonite in a melting bath of ZnSO4 for 10, 20, 40, 60 and 90 rain. The complexes were characterized by XRD, SEM and DRS. XRD analyses and SEM observations confirmed the diffusion of zinc to the clay surfaces. Antibacterial activity tests against Escherichia coli showed that bentonite did not present any antibacterial properties, but after alkaline ion exchange treatment, inhibition was noted. The highest antibacterial activity was observed with ZnO/bentonite composite alkaline ion exchange for 60 and 90 rain. Interestingly, the leaching test indicated that ZnO/bentonite did not present any risk for drinking water treatment.

关键词： alkaline ion exchange ZnO/bentonite nanocomposite antibacterial activity