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Inverted polymer solar cells with employing of electrochemical-anodizing synthesized TiO_2 nanotubes

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Chinese Physics B 2016年第4期25卷 320-324页

作者： Mehdi Ahmadi Sajjad rashidi Dafeh Hamed Fatehy Department of Physics Faculty of Science Vali-e-Asr University of Rafsanjan

An inverted structure of polymer solar cells based on Poly（3-hexylthiophene）（P3HT）：[6-6] Phenyl-（6） butyric acid methyl ester （PCBM） with using thin films of TiO2 nanotubes and nanoparticles as an efficient cathode buffer layer is developed. A total of three cells employing TiO2 thin films with different thickness values are fabricated. Two cells use layers of TiO2 nanotubes prepared via self-organized electrochemical-anodizing leading to thickness values of 203 and 423.7 nm, while the other cell uses only a simple sol-gel synthesized TiO2 thin film of nanoparticles with a thickness of 100 nm as electron transport layer. Experimental results demonstrate that TiO2 nanotubes with these thickness values are inefficient as the power conversion efficiency of the cell using 100-nm TiO2 thin film is 1.55%, which is more than the best power conversion efficiency of other cells. This can be a result of the weakness of the electrochemical anodizing method to grow nanotubes with lower thickness values. In fact as the TiO2 nanotubes grow in length the series resistance （Rs） between the active polymer layer and electron transport layer increases, meanwhile the fill factor of cells falls dramatically which finally downgrades the power conversion efficiency of the cells as the fill factor falls.

关键词： inverted polymer solar cells TiO2 nanotubes electrochemical-anodizing doctor blading

Oxidized organic molecules in the tropical free troposphere over Amazonia

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National Science Review 2024年第1期11卷 174-184页

作者： Qiaozhi Zha Diego Aliaga Radovan Krejci Victoria A.Sinclair Cheng Wu Giancarlo Ciarelli Wiebke Scholz Liine Heikkinen Eva Partoll Yvette Gramlich Wei Huang Markus Leiminger Joonas Enroth Otso Per?kyl? Runlong Cai Xuemeng Chen Alkuin Maximilian Koenig Fernando Velarde Isabel Moreno Tuukka Pet?j? Paulo Artaxo Paolo Laj armin Hansel Samara Carbone Markku Kulmala Marcos Andrade Douglas Worsnop Claudia Mohr Federico Bianchi Institute for Atmospheric and Earth System Research/Physics University of Helsinki Joint International Research Laboratory of Atmospheric and Earth System Sciences Nanjing University Department of Environmental Science & Bolin Centre for Climate Research Stockholm University Department of Chemistry and Molecular Biology University of Gothenburg Institute for Ion and Applied Physics University of Innsbruck Ionicon Analytik GmbH Laboratory for Atmospheric Physics Institute for Physics Research Universidad Mayor de San Andrés Institute of Physics University of Sao Paulo Institute for Geosciences and Environmental Research (IGE) University of Grenoble Alpes Agrarian Sciences Institute Federal University of Uberl?ndia Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology Department of Atmospheric and Oceanic Sciences University of Maryland Aerodyne Research Inc. Department of Environmental System Science ETH Zürich Switzerland and Laboratory of Atmospheric Chemistry Paul Scherrer Institute

New particle formation(NPF) in the tropical free troposphere(FT) is a globally important source of cloud condensation nuclei, affecting cloud properties and climate. Oxidized organic molecules(OOMs)produced from biogenic volatile organic compounds are believed to contribute to aerosol formation in the tropical FT, but without direct chemical observations. We performed in situ molecular-level OOMs measurements at the Bolivian station Chacaltaya at 5240 m above sea level, on the western edge of Amazonia. For the first time, we demonstrate the presence of OOMs, mainly with 4–5 carbon atoms, in both gas-phase and particle-phase(in terms of mass contribution) measurements in tropical FT air from Amazonia. These observations, combined with air mass history analyses, indicate that the observed OOMs are linked to isoprene emitted from the rainforests hundreds of kilometers away. Based on particle-phase measurements, we find that these compounds can contribute to NPF, at least the growth of newly formed nanoparticles, in the tropical FT on a continental scale. Thus, our study is a fundamental and significant step in understanding the aerosol formation process in the tropical FT.

关键词： oxidized organic molecules tropical aerosol formation Amazon free troposphere

Production of single-walled carbon nanotubes from methane over Co-Mo/MgO nanocatalyst:A comparative study of fixed and fluidized bed reactors

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Journal of Natural Gas Chemistry 2011年第4期20卷 372-376页

作者： Alimorad rashidi Roghayeh Lotfi Ehsaneh Fakhrmosavi Masoud Zare Nanotechnology Research Center Research Institute of Petroleum Industry(R.I.P.I.)West Blvd.of Azadi Sport Complex

In this study,the performances of fixed and fluidized bed reactors in the production of single-walled carbon nanotubes（SWNTs）have been *** both reactors,single-walled carbon nanotubes were grown by catalytic chemical vapor decomposition（CCVD）of methane over Co-Mo/MgO nanocatalyst under two different operating *** synthesized samples were characterized by TEM,TGA and Raman *** is found that the performance of a fluidized bed in the synthesis of carbon nanotubes is much better than that of a fixed *** quality of carbon nanotubes obtained from the fluidized bed was significantly higher than that from the fixed bed and the former one with the ID/IG ratio of 0.11 while the latter one with the ID/IG ratio of ***,the yield of SWNTs in the fluidized bed was 92 wt%,while it was 78 wt%in the fixed *** advantages of fluidized bed reactors for the synthesis of carbon nanotubes can be attributed to more available space for the growth of carbon nanotubes and more uniform temperature and concentration profiles.

关键词： single-walled carbon nanotubes chemical vapor deposition fixed bed reactor fluidized bed reactor

Processing and characterization of AZ91 magnesium alloys via a novel severe plastic deformation method:Hydrostatic cyclic extrusion compression(HCEC)

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Transactions of Nonferrous Metals Society of China 2021年第5期31卷 1303-1321页

作者： armin SIAHSARANI Ghader FARAJI School of Mechanical Engineering College of EngineeringUniversity of TehranTehran11155-4563Iran

Capability of a novel severe plastic deformation(SPD)method of hydrostatic cyclic extrusion compression(HCEC)for processing of hcp metallic rods with high length to diameter ratios was *** process was conducted in two consecutive cycles on the AZ91 magnesium alloy,and microstructural evolution,mechanical properties and corrosion behavior were *** results showed that the HCEC process was successively capable of producing ultrafine-grained long magnesium *** ability in improving strength and ductility simultaneously was also *** ultimate tensile strength and elongation to failure of the sample after the second cycle of the process were improved to be 2.46 and 3.8 times those of the as-cast specimen,*** of the microhardness after the second cycle was uniform and its average value was increased by 116%.The potentials derived from the polarization curves were high and the currents were much low for the processed ***,the diameter of the capacitive arcs derived from the Nyquist curves was large in the HCEC processed *** finite element analysis indicated the independency of HCEC load from the length in comparison to the conventional *** is a unique SPD method,which can produce long ultrafine-grained rods with a combination of superior mechanical and corrosion properties.

关键词： severe plastic deformation cyclic extrusion compression corrosion behavior mechanical properties hydrostatic pressure

Characteristics of holey fibers fabricated at different drawing speeds

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Chinese Optics Letters 2007年第3期5卷 131-134页

作者： Faramarz E.Seraji Mahnaz rashidi Maryam Karimi Optical Communication Group Iran Telecom Research Center Tehran Iran Physics Group Guilan University RashtIran Physics Group Razi University KermanshahIran

The effects of high drawing speeds on parameters of holey fibers are presented. A holey fiber preform structure was made by using tube-in-tube method and was drawn at high speeds with an aim of mass production to meet the demand of next generation communication systems. Transmission parameters such as numerical aperture and normalized frequency of the fabricated holey fibers have been measured and compared with theoretical values based on effective index method. Although the fabricated holey fibers were not of high quality, the analyses of the parameters have shown promising outlook for fabrication of such fibers.

关键词： Characteristics of holey fibers fabricated at different drawing speeds

A Novel Approach for Energy and Water Conservation by Using Silver-Carbon Quantum Dots Hybrid Nanofluids in Wet Cooling Towers Systems

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Journal of Thermal Science 2021年第5期30卷 1827-1841页

作者： HAMID Mousavi SEYED MOSTAFA Tabatabaee Ghomshe ALIMORAD rashidi MASOUMEH Mirzaei Department of Chemical Engineering Mahshahr BranchIslamic Azad UniversityMahshahrIran Nanotechnology Research Center Research Institute of Petroleum Industry(RIPI)West Blvd.Azadi Sports ComplexP.O.Box 146651998TehranIran

This study presents the use of Silver-Carbon Quantum Dots(Ag-CQD)hybrid nanofluids,prepared by a facile wet chemical method,for heat transfer enhancement of wet cooling towers *** samples were characterized using different analyses,including FT-IR,XRD and *** synthesizing the CQD,it was hybridized with silver nanoparticles and dispersed in water,using ultrasonic *** viscosity and density of the prepared nanofluid were investigated as a function of temperature and nanoparticles concentration,which demonstrated that there were no noticeable changes at lower particles ***,thermal conductivity and convective heat transfer coefficient were measured to evaluate the heat transfer enhancement of the *** 45℃ and 0.5 wt%,the most significant thermal conductivity improvement compared to the base fluid was 24%;and 28%enhancement of the heat transfer coefficient was obtained at Reynolds number of *** nanofluid performance was evaluated in a wet cooling tower for investigating the efficiency and water consumption *** results indicated that the efficiency of the cooling tower,by applying Ag-CQD nanofluid,enhanced from 23.72%to 28.23%;consequently,the amount of the consumed water decreased from 80.76 mL·min^(−1)to 69.67 mL·min^(−1).The results proved that the prepared nanofluid is a successful and promising candidate to enhance heat transfer.

关键词： nanofluid carbon quantum dot silver hybrid heat transfer wet cooling tower

Improving methane storage on wet activated carbons at various amounts of water

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燃料化学学报 2012年第4期40卷 385-389页

作者： MOHAMMAD JABER DARABI MAHBOUB ALI AHMADPOUR HAMED rashidi Department of Chemical Engineering Faculty of EngineeringFerdowsi University of Mashhad

Different mesoporous activated carbons were prepared by both chemical and physical activation processes and were examined for methane uptake in the presence of *** isotherms were obtained at wet condition by wetting samples with water at mass ratio of water/carbon(R) close to *** compare,the amount of methane storage were also measured at dry *** maximum amount of methane stored was attained as 237 V/V at R=1.0 by hydrate formation at the methane critical *** the next step,mass ratios of water/carbon were changed to investigate various amount of water for methane storage *** other values of mass ratio of water/carbon(R=0.8 and 1.4) were selected and methane isotherms were obtained at the same *** values of 210 and 248 V/V were reached for methane storage,*** was also observed that,in the pressure range lower than hydrate pressure,by increasing water ratio the hydrate formation pressure was decreased and methane uptake was much less than that of dry condition due to pore filling by water.

关键词： methane storage hydrate isotherm water wetting

Preparation and Characterization of Novel Thermostable Polyamides Bearing Different Photoactive Pendent Architectures with Antibacterial Properties

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Chinese Journal of Polymer Science 2016年第6期34卷 766-776页

作者： Seyed Mojtaba Amininasab Azad rashidi Mehdi Taghavi Zahed Shami Department of Chemistry University of KurdistanSanandaj 66177-15175Iran Polymer Chemistry Research Laboratory Faculty of ScienceShahid Chamran University of Ahvaz 61357-43337Iran

Three diamine monomers with different derivatives of imidazole heterocyclic ring, aryl ethers and electron withdrawing trifluoromethyl groups in the backbone were synthesized and used in polycodensation reaction with various aliphatic and aromatic dicarboxylic acids for preparation of a series of novel polyamides （PAs）. The PAs were obtained in high yields and possessed inherent viscosities in the range of 0.26-0.75 dL/g. All of the polymers were amorphous in nature, showed outstanding solubility and could be easily dissolved in amide-type polar aprotic solvents. They showed good thermal stability with glass transition temperatures between 162-302 ℃. Thermogravimetric analysis showed that all polymers were stable, with 10% weight loss recorded above 421 ℃in N2 atmospheres. All the PAs presented fluorescence upon irradiation with ultraviolet light and thus showed promise for applications in electroluminescent devices. The monomers and PAs were also screened for antibacterial activity against Gram positive and Gram negative bacteria.

关键词： Photoactive polyamides Anthracene Fluorene Carbazole Antibacterial activity.

Multi-soliton fusion phenomenon of Burgers equation and fission, fusion phenomenon of Sharma-Tasso-Olver equation

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Journal of Ocean Engineering and Science 2017年第2期2卷 120-126页

作者： Harun Or-Roshid M.M.rashidi Department of Mathematics Pabna University of Science and TechnologyPabna 6600Bangladesh Shanghai Key Lab of Vehicle Aerodynamics and Vehicle Thermal Management Systems Tongji University4800 Cao An Rd.JiadingShanghai 201804China ENN-Tongji Clean Energy Institute of Advanced Studies China

A direct rational exponential scheme is proposed to construct exact multi-soliton solutions and its fission,fusion phenomena after interaction of the solitons has been *** have considered the Burgers and Sharma-Tasso-Olver equation as two concrete examples to show the fission and fusion of the solitary wave and the solitons,*** improve different structured multi-soliton solutions with possible conditions for fission and fusion of the Burgers and the Sharma-Tasso-Olver equations arises in plasma physics and in ocean *** amplitude and velocity relations between solitons and/or solitary waves before and after interactions are given and a possible condition for fission and fusion is ***,three-dimensional plots of the wave solutions are given to visualize the dynamics of the model.©2017 Shanghai Jiaotong *** by Elsevier B.V.

关键词： Direct rational exponential scheme Burger equation Sharma-Tasso-Olver equation Traveling wave solutions Multi-soliton