University of KashanJournal of Nanostructures2251-78713320130901Synthesis of TiO2 Nanoparticle and its Application to Graphite Composite Electrode for Hydroxylamine Oxidation269275546610.7508/jns.2013.03.001ENM.Mazloum-ArdakaniDepartment of Chemistry, Faculty of Science, Yazd University, Yazd, 89195-741, I.R. IranA. R.KhoshrooDepartment of Chemistry, Faculty of Science, Yazd University, Yazd, 89195-741, I.R. IranJournal Article20140518In this work, sol-gel method was used tosynthesize titanium dioxide nanoparticles (TiO<sub>2</sub>). The TiO<sub>2</sub>nanoparticles was characterized by Scanning Electron Microscopy (SEM), x-ray diffraction (XRD) and BET technique.The TiO<sub>2</sub> and coumarin derivative (7-(1,3-dithiolan-2-yl)-9, 10-dihydroxy-6H-benzofuro [3,2-c] chromen-6-on) were incorporated in a graphite composite electrode. The resulting modified electrode displayed a good electrocatalytic activity for the oxidation of hydroxylamine, which leads to a reduction in its overpotential by more than 520 mV. Differential pulse voltammetry (DPV) of hydroxylamine at the modified electrode exhibited a linear dynamic range (between 0.5 and 500.0 µM) with a detection limit (3σ) of 0.133 μM. The high sensitivity, ease of fabrication and low cost of this modified electrode for the detection of hydroxylamine demonstrate its potential sensing applications.https://jns.kashanu.ac.ir/article_5466_d44c0de4b37d9ff31719c1b8c8e78736.pdfUniversity of KashanJournal of Nanostructures2251-78713320130901Effect of Thickness on the Structural Properties of Tellurium Film Prepared by Thermal Evaporation277280546710.7508/jns.2013.03.002ENM.ManouchehrianDepartment of physics, Science Faculty, South Tehran Branch, Islamic Azad University, Tehran, Iran.M. M.LarijaniNuclear Science and Technology Research Institute, P. O. Box 31485-498, Karaj, Iran.M. A.Moghri MoazzenYoung Researchers and Elite Club, Karaj Branch, Islamic Azad University, Karaj, Iran.Journal Article20140518In this research, tellurium (Te) film with thicknesses of 100-250 nm were deposited on ceramic substrates by thermal evaporation at 373 K. The thickness of the film was determined by Rutherford backscattering spectroscopy. The influence of the thickness on the structural, morphological and molecular bonds was characterized using XRD, scanning electron microscope, and Raman spectroscopy. The XRD results confirmed that increasing the thickness, increased the intensity of the peaks, indicating increased crystallinity. SEM images indicated that the density of the film and holes in the film decreased as thickness increased. The Raman spectrum revealed that the TeO<sub>2</sub> molecular bond formed on the surface only at room temperature up to 100 nm in thickness; as thickness increased, this bond was observed at 323 K.https://jns.kashanu.ac.ir/article_5467_b41c8df96af60072aede937692197b52.pdfUniversity of KashanJournal of Nanostructures2251-78713320130901Thermal Inactivation and Aggregation of Lysozyme in the Presence of Nano- TiO2 and Nano-SiO2 in Neutral pH281288546810.7508/jns.2013.03.003ENB.ShareghiDepartment of Biology, Faculty of Science, University of Shahrekord, Shahrekord, I. R. Iran.A.HashemianDepartment of Biology, Faculty of Science, University of Shahrekord, Shahrekord, I. R. Iran.S.FarhadianDepartment of Biology, Faculty of Science, University of Shahrekord, Shahrekord, I. R. Iran.M.Salavati-NiasariInstitute of Nano Science and Nano Technology, University of Kashan, Kashan, I. R. Iran.B.SaffarDepartment of genetic, Faculty of Science, University of Shahrekord, Shahrekord, I. R. Iran.H.MoshtaghiDepartment of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of
Shahrekord, Shahrekord, I. R. IranJournal Article20140518Protein aggregation is a problem in biotechnology. High temperature is one of the most important reasons to enhance enzyme inactivation and aggregation in industrial systems. This work focuses on the effect of TiO<sub>2</sub> and SiO<sub>2</sub> nanoparticles on refolding and reactivation of lysozyme. In the presence of TiO<sub>2</sub> and SiO<sub>2</sub> nanoparticles, after enzyme heat treatment at 98<sup>◦</sup>C for 30 min, not only aggregates were observed, but the amount of those increased. Hence the residual activity of lysozyme (without additives) and even in the presence of TiO<sub>2</sub> and SiO<sub>2</sub> nanoparticles after heat treatment was very low (<5%). T<sub>m</sub> of the aggregated lysozyme after this heat treatment was decreased with increasing concentrations of TiO<sub>2</sub> and SiO<sub>2</sub> nanoparticles from 0 to 0.02 mg/ml in neutral pH, Whether the T<sub>m</sub> of natural enzyme was above 373 (K) or 100<sup>◦</sup>C. these nanoparticles help enzyme denaturation and misfolding in heating.https://jns.kashanu.ac.ir/article_5468_6cbf69b1d2a600040b10ebe7e863acfa.pdfUniversity of KashanJournal of Nanostructures2251-78713320130901Investigation of Laminar Pulsating Nanofluid Flow and Heat Transfer in a Rectangular Channel289301546910.7508/jns.2013.03.004ENP.ElyasiMechanical Engineering Department, Faculty of Engineering, Shahrekord University, Shahrekord, IranM.Ziaei-RadMechanical Engineering Department, Faculty of Engineering, Shahrekord University, Shahrekord, IranJournal Article20140518In this study, two-dimensional pulsating unsteady flow of nanofluid through a rectangular channel with isothermal walls is investigated numerically. The set of resultant algebraic equations is solved simultaneously using SIMPLE algorithm to obtain the velocity and pressure distribution within the channel. The effects of several parameters, such as volume fraction of different nanoparticles, Reynolds number, and the amplitude and frequency of pulsation flow, on the rate of heat transfer and pressure drop are examined. The results show that the heat transfer enhancement on the target surface obtained by the flow pulsation highly depends on pulsating velocity. It can also be seen that total Nusselt number increases significantly due to increase in amplitude of pulsation and volume fraction of nanoparticles. Analysis also reveals that pressure drop for the alumina nanoparticles is much greater than that of the base fluid.https://jns.kashanu.ac.ir/article_5469_88e6925ee9c1f34be16fca0763f9ea22.pdfUniversity of KashanJournal of Nanostructures2251-78713320130901Young’s Modulus and Poisson’s Ratio of Monolayer Graphyne303307547010.7508/jns.2013.03.005ENH.RouhiDepartment of Mechanical Engineering, University of Guilan, Rasht, Iran, P.O. Box 3756M.MirnezhadDepartment of Mechanical Engineering, University of Guilan, Rasht, Iran, P.O. Box 3756R.AnsariDepartment of Mechanical Engineering, University of Guilan, Rasht, Iran, P.O. Box 3756M.FaghihnasiriDepartment of Physics, University of Guilan, Rasht, Iran, P.O. Box 41335-1914Journal Article20140518Despite its numerous potential applications, two-dimensional monolayer graphyne, a novel form of carbon allotropes with sp and sp<sup>2</sup> carbon atoms, has received little attention so far, perhaps as a result of its unknown properties. Especially, determination of the exact values of its elastic properties can pave the way for future studies on this nanostructure. Hence, this article describes a density functional theory (DFT) investigation into elastic properties of graphyne including surface Young’s modulus and Poisson’s ratio. The DFT analyses are performed within the framework of generalized gradient approximation (GGA), and the Perdew–Burke–Ernzerhof (PBE) exchange correlation is adopted. This study indicates that the elastic modulus of graphyne is approximately half of that of graphene due to its lower number of bonds.https://jns.kashanu.ac.ir/article_5470_ab2937da476cca209e123e4e1352129a.pdfUniversity of KashanJournal of Nanostructures2251-78713320130901Optimization of Sensitivity and Stability of Gold/Silver bi-Layer Thin Films Used in Surface Plasmon Resonance Chips309313547110.7508/jns.2013.03.006ENM.GhorbanpourChemical Engineering Department, University of Mohaghegh Ardabili, 56199-11367, Ardabil, Iran.Journal Article20140518The aim of this study is experimental assay of sensitivity and stability of a bimetallic silver/gold SPR sensor chip. This chip utilizes the sensitivity of the silver and the stability of the gold. Moreover, the Silver layer (instead of usual Cr or Ti layer) was used as an adhesive intermediate layer between the Gold layer and the glass substrate. The optimization of the Gold/Silver thickness using SPR analysis and physical and chemical stability tests showed that the 20/30 gold/silver composite resulting in a better precision and more stable SPR sensing chip.https://jns.kashanu.ac.ir/article_5471_7a5238a11912fc2e67f63b9dba3b41e6.pdfUniversity of KashanJournal of Nanostructures2251-78713320130901Embedding of a 2D Graphene System in Non-Commutative Space315322547210.7508/jns.2013.03.007ENM.MonemzadehDepartment of Physics, University of Kashan, Kashan, IranM.TaieDepartment of Physics, University of Kashan, Kashan, IranB.KhoshnevisanDepartment of Physics, University of Kashan, Kashan, IranJournal Article20140518The BFT approach is used to formulate the electronic states in graphene through a non-commutative space in the presence of a constant magnetic field B for the first time. In this regard, we introduce a second class of constrained system, which is not gauge symmetric but by applying BFT method and extending phase space, the second class constraints converts to the first class constraints so the system becomes a gauge symmetric.https://jns.kashanu.ac.ir/article_5472_3efcac24107ed1cf9e0705a04dfccf3c.pdfUniversity of KashanJournal of Nanostructures2251-78713320130901Study of Non-Isothermal Crystallization Kinetics of Biodegradable Poly(ethylene adipate)/SiO2 Nanocomposites323331547310.7508/jns.2013.03.008ENM. R.MemarzadehDepartment of Chemistry, University of Kashan, Kashan, IranM.Mohsen-NiaInstitute of Nanoscience and Nanotechnology, University of Kashan, Kashan, Iran
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Department of Engineering, University of Kashan, Kashan, IranJournal Article20140518Poly(ethylene adipte) and poly(ethylene adipate)/silica nanocomposite (PEAd/SiO2) containing 3 wt. % SiO2 were prepared by an in situ method. The examinations on the non-isothermal crystallization kinetic behavior have been conducted by means of differential scanning calorimeter (DSC). The Avrami, Ozawa, and combined Avrami and Ozawa equations were applied to describe the crystallization kinetics and to determine the crystallization parameters of the prepared PEAd/SiO2 nanocomposites. It is found that the inclusion of the silica nanoparticles can accelerate the nucleation rate due to heterogeneous nucleation effect of silica on the polymer matrix. According to the obtained results, the combined Avrami and Ozawa equation shown that the better model for examination of this system.https://jns.kashanu.ac.ir/article_5473_88891d91339f7937abb4766791c3a34b.pdfUniversity of KashanJournal of Nanostructures2251-78713320130901Synthesis and Characterization of Carbon Nanotubes Catalyzed by TiO2 Supported Ni, Co and Ni-Co Nanoparticles via CCVD333339547410.7508/jns.2013.03.009ENA. A.HosseiniDepartment of Physics, University of Mazandaran, Babolsar, Iran.F.DoustanDepartment of Physics, University of Mazandaran, Babolsar, Iran.M.Akbarzadeh PashaDepartment of Physics, University of Mazandaran, Babolsar, Iran.Journal Article20140518Monometallic and bimetallic Ni and Co catalytic nanoparticles supported on Titanium dioxide (rutile phase) substrate were prepared by wet impregnation method. These nanoparicles were used as catalysts for synthesis of multiwalled carbon nanotubes (MWCNTs) from acetylene decomposition at 700°C by the catalytic chemical vapor deposition (CCVD) technique. The nanomaterials (catalyst and CNTs) were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Raman spectroscopy. In this paper, the usage of TiO<sub>2</sub> powder as catalyst support was examined and the effect of applied catalyst type on characteristics of grown CNTs was investigated. The results showed that the rutile phase of TiO<sub>2</sub> powder can be applied as a suitable catalyst support in CNT growth process. Furthermore, it was observed that the CNTs synthesized on Ni-Co bimetallic catalyst possess smaller average diameters, better quality and less amorphous carbon compared to Ni and Co monometallic catalyst types.https://jns.kashanu.ac.ir/article_5474_9695596a4eecbaec1efbbdf15c15bce8.pdfUniversity of KashanJournal of Nanostructures2251-78713320130901Application of Magnetite Nanoparticles in Phenylalanine Removal from Water Samples341346547510.7508/jns.2013.03.010ENN.MirDepartment of Chemistry, University of Zabol, P. O. Box 98615-538, Zabol, I.R. IranA. R.NikkaranDepartment of Chemistry, University of Zabol, P. O. Box 98615-538, Zabol, I.R. IranM.Nejati-YazdinejadDepartment of Chemistry, University of Zabol, P. O. Box 98615-538, Zabol, I.R. IranA. A.MirDepartment of Chemistry, University of Zabol, P. O. Box 98615-538, Zabol, I.R. IranJournal Article20140518The purpose of the current research is investigating the phenylalanine removal by using magnetic nanoparticles (Fe<sub>3</sub>O<sub>4</sub>) from water samples. The effect of pH, contact time and phenylalanine concentration on phenylalanine adsorption efficiency by magnetite nanoparticles are studied in a batch system. Transmission electron microscopy (TEM), X-ray Diffraction Patterns (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) were used to characterize the synthesized magnetite nanoparticles.https://jns.kashanu.ac.ir/article_5475_24d5038ab67e825e9317dbf73b219c6f.pdfUniversity of KashanJournal of Nanostructures2251-78713320130901Effect of Temperature and Pressure on Correlation Energy in a Triplet State of a Two Electron Spherical Quantum Dot347357547610.7508/jns.2013.03.011ENA.Rejo JeiceDepartment of Physics, Annai Velankannai College, Tholayavattam-629157, IndiaK. S.Joseph WilsonDepartmant of Physics, Arul Anandar College, Madurai-625514, IndiaJournal Article20140518The combined effect of hydrostatic pressure and temperature on correlation energy in a triplet state of two electron spherical quantum dot with square well potential is computed. The result is presented taking GaAs dot as an example. Our result shows the correlation energies are i)negative in the triplet state contrast to the singlet state ii) it increases with increase in pressure iii)further decreases due to the application of temperature iv) it approaches zero as dot size approaches infinity and v) it contribute 10% decrement in total confined energy to the narrow dots. All the calculations have been carried out with finite models and the results are compared with existing literature.https://jns.kashanu.ac.ir/article_5476_d5c462a387b8941cdf28b3b63942cf18.pdfUniversity of KashanJournal of Nanostructures2251-78713320130901Finite-Difference Time-Domain Simulation of Light Propagation in 2D Periodic and Quasi-Periodic Photonic Structures359364547710.7508/jns.2013.03.012ENN.DadashzadehIslamic Azad University of Hadishahr, Hadishahr, Iran
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Belarusian State University, Nezavisimostiave. 4, 220030 Minsk, BelarusO. G.RomanovBelarusian State University, Nezavisimostiave. 4, 220030 Minsk, BelarusJournal Article20140518Ultra-short pulse is a promising technology for achieving ultra-high data rate transmission which is required to follow the increased demand of data transport over an optical communication system. Therefore, the propagation of such type of pulses and the effects that it may suffer during its transmission through an optical waveguide has received a great deal of attention in the recent years. We provide an overview of recent theoretical developments in a numerical modeling of Maxwell's equations to analyze the propagation of short laser pulses in photonic structures. The process of short light pulse propagation through 2D periodic and quasi-periodic photonic structures is simulated based on Finite-Difference Time-Domain calculations of Maxwell’s equations.https://jns.kashanu.ac.ir/article_5477_c331e9bed80cb1c8e485655532c1f04d.pdfUniversity of KashanJournal of Nanostructures2251-78713320130901Efficiency Enhancement of Si Solar Cells by Using Nanostructured Single and Double Layer Anti-Reflective Coatings365369547810.7508/jns.2013.03.013ENM.MoradiInstitute of Nanoscience and Nanotechnology, University of Kashan, 87317-51167 Kashan, IranZ.RajabiInstitute of Nanoscience and Nanotechnology, University of Kashan, 87317-51167 Kashan, IranJournal Article20140518The effect of single and double-layer anti-reflective coatings on efficiency enhancement of silicon solar cells was investigated. The reflectance of different anti-reflection structures were calculated using the transfer matrix method and then to predict the performance of solar cells coated by these structures, the weighted average reflectance curves were used as an input of a PC1D simulation. In contrast to the single-layer anti-reflection coating that has not significant contribution to efficiency enhancement, the double-layer was obtained to be practical to improve the efficiency of Si solar cells. Considerable enhancement in the conversion efficiency (E<sub>ff</sub>) and short-circuit current density (J<sub>sc</sub>) were obtained for TiO<sub>2</sub>/ SiO<sub>2</sub> double-layer anti-reflective coating.https://jns.kashanu.ac.ir/article_5478_6887835c565dba6480057623df535099.pdf