Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695714220191126Calculation of differential and total cross sections for Positrion-Hydrogen impact with second-order Born-Faddeev approximation in excitation channelCalculation of differential and total cross sections for Positrion-Hydrogen impact with second-order Born-Faddeev approximation in excitation channel1231321073FARFathiJournal Article20191126In this paper, we have implemented a three-body formalism, where the interaction potential is replaced by the transition matrix, in the excitation channel for the collision of positron and atomic hydrogen. Differential and total cross sections are calculated while the first and second order terms of the FWL (Faddeev-Watson-Lovelace) series in the transition from ground state to the first excited state of atomic hydrogen are included. The impact energy range of to and the scattering angle of the scattered positron in the range of (1-180) degrees are selected. At last, the results are compared with the available theoretical data in the literatureIn this paper, we have implemented a three-body formalism, where the interaction potential is replaced by the transition matrix, in the excitation channel for the collision of positron and atomic hydrogen. Differential and total cross sections are calculated while the first and second order terms of the FWL (Faddeev-Watson-Lovelace) series in the transition from ground state to the first excited state of atomic hydrogen are included. The impact energy range of to and the scattering angle of the scattered positron in the range of (1-180) degrees are selected. At last, the results are compared with the available theoretical data in the literaturehttps://ijpr.iut.ac.ir/article_1073_c63c62ac30a9eb6d78fd85e8ea6fed22.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695714220191126Extraordinary high spectral sensitivity in surface plasmon resonance sensor by multi-mode sensing scheme formeasuring the thickness of an adsorbed layer of specific refractive indexExtraordinary high spectral sensitivity in surface plasmon resonance sensor by multi-mode sensing scheme formeasuring the thickness of an adsorbed layer of specific refractive index1331381074FAHMohammadhosseiniAAhmadkhan KordbachehMGhanaatshoarJournal Article20191126In this paper surface plasmon resonance sensor is studied by using gold and silver in its structure respectively, also the possibility of extraordinary high spectral sensitivity by using multimode sensing scheme is being investigated in this sensor. It is shown that due to the extraordinary high spectral sensitivity of surface plasmon resonance sensor measuring adsorbate layer thickness could be done effectivelyIn this paper surface plasmon resonance sensor is studied by using gold and silver in its structure respectively, also the possibility of extraordinary high spectral sensitivity by using multimode sensing scheme is being investigated in this sensor. It is shown that due to the extraordinary high spectral sensitivity of surface plasmon resonance sensor measuring adsorbate layer thickness could be done effectivelyhttps://ijpr.iut.ac.ir/article_1074_878f4351e455c9b65d2b1ebd02c7bc3d.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695714220191126Engineering photonic band gap in 1D phonic crystals using fresnel coefficients and comparing with the results of transfer matrix meghodEngineering photonic band gap in 1D phonic crystals using fresnel coefficients and comparing with the results of transfer matrix meghod1391461075FAARahmatnezamabadSRoshanentezarHAfkhamiBRahmatnezamabadJournal Article20191126In this paper photonic band gaps of 1D photonic crystal are compared by using transfer matrix method and Fresnel coefficients method. In Fresnel coefficients method, the refractive indices of each layer and incidence light angle to the surface are used for calculating Fresnel coefficients, and then the necessary and sufficient condition for a 100% reflection from the surface of double layer dielectrics is applied in such a way that reflection coefficient tends to unity so that photonic band gaps are determined. But in transfer matrix method there are some complications needed for solving quadratic partial differential equations and applying continuity of tangent components of fields and Bloch’s condition, though the results are the sameIn this paper photonic band gaps of 1D photonic crystal are compared by using transfer matrix method and Fresnel coefficients method. In Fresnel coefficients method, the refractive indices of each layer and incidence light angle to the surface are used for calculating Fresnel coefficients, and then the necessary and sufficient condition for a 100% reflection from the surface of double layer dielectrics is applied in such a way that reflection coefficient tends to unity so that photonic band gaps are determined. But in transfer matrix method there are some complications needed for solving quadratic partial differential equations and applying continuity of tangent components of fields and Bloch’s condition, though the results are the samehttps://ijpr.iut.ac.ir/article_1075_1aff252d97e69b3e168353dc5c5f9bcd.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695714220191126Optical and structural properties of ZnO hexagonal rods prepared by thermal chemical vapor deposition techniqueOptical and structural properties of ZnO hexagonal rods prepared by thermal chemical vapor deposition technique1481531076FAAReyhaniM. RKhanlaryVVahediJournal Article20191126In this research, ZnO nanostructure hexagonal pyramid rods with high optical and structural quality were synthesized by the simple thermal chemical vapor deposition of Zn powder without a metal catalyst. Surface morphologies were characterized by scanning electron microscopy (SEM). XRD analyses demonstrated that ZnO hexagonal pyramid rods had a wurtzite structure with the orientation of (002). Investigation of optical properties of samples by photoluminescence spectrum exhibited a sharp UV emission peak at 380nm. The quality and composition of the ZnO pyramid rods were characterized using the Fourier transform infrared spectrum (FTIR) at room temperature. In addition, the growth mechanism of ZnO hexagonal rods is also briefly discussed.In this research, ZnO nanostructure hexagonal pyramid rods with high optical and structural quality were synthesized by the simple thermal chemical vapor deposition of Zn powder without a metal catalyst. Surface morphologies were characterized by scanning electron microscopy (SEM). XRD analyses demonstrated that ZnO hexagonal pyramid rods had a wurtzite structure with the orientation of (002). Investigation of optical properties of samples by photoluminescence spectrum exhibited a sharp UV emission peak at 380nm. The quality and composition of the ZnO pyramid rods were characterized using the Fourier transform infrared spectrum (FTIR) at room temperature. In addition, the growth mechanism of ZnO hexagonal rods is also briefly discussed.https://ijpr.iut.ac.ir/article_1076_5f7e621e992c71a340885be904a02388.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695714220191126Fabrication of polymer Schottky diode with Al-PANI/MWCNT-Au structureFabrication of polymer Schottky diode with Al-PANI/MWCNT-Au structure1541601077FAAHajibadaliMBaghaei NejhadGHFarziJournal Article20191126In this research, Schottky diode with Al-PANI/MWCNT-Au structure was fabricated using spin coating of composite polymer and physical vapor deposition of metals. For this purpose, a thin layer of gold was coated on glass and then composite of polyaniline/multi-walled carbon nanotube was synthesized and spin-coated on gold layer. Finally, a thin layer of aluminum was coated on polymer layer. The current-voltage characteristics of diode were studied and found that I-V curve is nonlinear and nonsymmetrical, showing rectifying behavior. I-V characteristics plotted on a logarithmic scale for Schottky diode showed two distinct power law regions. At lower voltages, the mechanism follows Ohm’s Law and at higher voltages, the mechanism is consistent with space charge limited conduction (SCLC) emission. The parameters extracted from I-V characteristics were also calculated.In this research, Schottky diode with Al-PANI/MWCNT-Au structure was fabricated using spin coating of composite polymer and physical vapor deposition of metals. For this purpose, a thin layer of gold was coated on glass and then composite of polyaniline/multi-walled carbon nanotube was synthesized and spin-coated on gold layer. Finally, a thin layer of aluminum was coated on polymer layer. The current-voltage characteristics of diode were studied and found that I-V curve is nonlinear and nonsymmetrical, showing rectifying behavior. I-V characteristics plotted on a logarithmic scale for Schottky diode showed two distinct power law regions. At lower voltages, the mechanism follows Ohm’s Law and at higher voltages, the mechanism is consistent with space charge limited conduction (SCLC) emission. The parameters extracted from I-V characteristics were also calculated.https://ijpr.iut.ac.ir/article_1077_a71c5a143df24982ac4ae5aa3595b17c.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695714220191126Investigation of SiO2 thin films dielectric constant using ellipsometry techniqueInvestigation of SiO2 thin films dielectric constant using ellipsometry technique1611661078FAPSangpourKKhosravyMKazemzadJournal Article20191126In this paper, we studied the optical behavior of SiO2 thin films prepared via sol-gel route using spin coating deposition from tetraethylorthosilicate (TEOS) as precursor. Thin films were annealed at different temperatures (400-600oC). Absorption edge and band gap of thin layers were measured using UV-Vis spectrophotometery. Optical refractive index and dielectric constant were measured by ellipsometry technique. Based on our atomic force microscopic (AFM) and ellipsometry results, thin layers prepared through this method showed high surface area, and high porosity ranging between 4.9 and 16.9, low density 2 g/cm, and low dielectric constant. The dielectric constant and porosity of layers increased by increasing the temperature due to the changes in surface roughness and particle size.In this paper, we studied the optical behavior of SiO2 thin films prepared via sol-gel route using spin coating deposition from tetraethylorthosilicate (TEOS) as precursor. Thin films were annealed at different temperatures (400-600oC). Absorption edge and band gap of thin layers were measured using UV-Vis spectrophotometery. Optical refractive index and dielectric constant were measured by ellipsometry technique. Based on our atomic force microscopic (AFM) and ellipsometry results, thin layers prepared through this method showed high surface area, and high porosity ranging between 4.9 and 16.9, low density 2 g/cm, and low dielectric constant. The dielectric constant and porosity of layers increased by increasing the temperature due to the changes in surface roughness and particle size.https://ijpr.iut.ac.ir/article_1078_cbf59822817ea55f04d9681a97fea0bd.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695714220191126Synchronization of the Kuramoto model on the complex networks with bimodal intrinsic frequency distributionSynchronization of the Kuramoto model on the complex networks with bimodal intrinsic frequency distribution1671771079FANKhodadoostanTMalakoutikhahFShahbaziJournal Article20191126In this work, we study the Kuramoto model on scale-free, random and small-world networks with bimodal intrinsic frequency distributions. We consider two models: in one of them, the coupling constant of the ith oscillator is independent of the number of oscillators with which the oscillator interacts, and in the other one the coupling constant is renormalized with the number of oscillators with which the oscillator interacts. For the first model, the time which is required for reaching the stationary state is more than the time which is needed in the second one. Also, for both models the order parameter of the random and scale-free network decreases by increasing the intrinsic frequency with a bimodal distribution. Unlike scale-free and random networks, the order parameter of the small-world network increases by increasing the frequency at first. But later, it decreases and then starts to oscillate.In this work, we study the Kuramoto model on scale-free, random and small-world networks with bimodal intrinsic frequency distributions. We consider two models: in one of them, the coupling constant of the ith oscillator is independent of the number of oscillators with which the oscillator interacts, and in the other one the coupling constant is renormalized with the number of oscillators with which the oscillator interacts. For the first model, the time which is required for reaching the stationary state is more than the time which is needed in the second one. Also, for both models the order parameter of the random and scale-free network decreases by increasing the intrinsic frequency with a bimodal distribution. Unlike scale-free and random networks, the order parameter of the small-world network increases by increasing the frequency at first. But later, it decreases and then starts to oscillate.https://ijpr.iut.ac.ir/article_1079_d255d7125673b5cf25981c7980fcc091.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695714220191126Studying stimulated Raman scattering using relativistic Vlasov equationStudying stimulated Raman scattering using relativistic Vlasov equation1791861080FAMSharifiAParvazianJournal Article20191126Backward stimulated Raman scattering using one-dimensional relativistic Vlasov code is investigated. For conditions similar to those of Single-Hot-Spot experiments, the growth and saturation of SRS are studied. Analysis of electron distribution function, longitudinal electrostatic fields, transverse electromagnetic fields, and electron density shows that kinetic effects play an important role in the saturation of this instability. SRS amplifies the longitudinal field amplitude and could trap, accelerate, and preheat the electrons.Backward stimulated Raman scattering using one-dimensional relativistic Vlasov code is investigated. For conditions similar to those of Single-Hot-Spot experiments, the growth and saturation of SRS are studied. Analysis of electron distribution function, longitudinal electrostatic fields, transverse electromagnetic fields, and electron density shows that kinetic effects play an important role in the saturation of this instability. SRS amplifies the longitudinal field amplitude and could trap, accelerate, and preheat the electrons.https://ijpr.iut.ac.ir/article_1080_1a9dc84dea74215500d74ce31b24c503.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695714220191126A study on melting process of perylene using molecular dynamics simulationA study on melting process of perylene using molecular dynamics simulation1871921081FAMPeyvastehSSetayeshiMVaez ZadehRAfzal ZadehJournal Article20191126Melting process of perylene is investigated using molecular dynamics simulation. Some of thermodynamic properties such as potential energy and transition order parameter are calculated as a function of temperature in the range of 500 K-600 K. These calculations are performed by two different methods in NPT and NVT ensembles. The selected interaction potential is Re-squared and the simulations are performed by LAMMPS (a classic molecular dynamics code). The results show that NPT ensemble is more appropraite for the study of melting process than NVT ensemble and shows a good agreement with experimental melting temperature.Melting process of perylene is investigated using molecular dynamics simulation. Some of thermodynamic properties such as potential energy and transition order parameter are calculated as a function of temperature in the range of 500 K-600 K. These calculations are performed by two different methods in NPT and NVT ensembles. The selected interaction potential is Re-squared and the simulations are performed by LAMMPS (a classic molecular dynamics code). The results show that NPT ensemble is more appropraite for the study of melting process than NVT ensemble and shows a good agreement with experimental melting temperature.https://ijpr.iut.ac.ir/article_1081_a1b838900456c72d83f0e4696206a030.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695714220191126Description of nuclear many-body interactions within the framework of quantum deformation theoryDescription of nuclear many-body interactions within the framework of quantum deformation theory1931991082FAEYaghoubiopourJournal Article20191126A fermion realization of compact symplectic algebra provides a natural framework for studying pairing correlations of many-body interactions in nuclei. Here, we use quantum deformation concept in order to describe pairing correlations in atomic nuclei. While the nondeformed limit of the theory provides a reasonable and overall description of certain nuclear properties and fine structure effects, the results show that the q deformation plays a significant role in understanding higher-order effects in the many-body interactions.A fermion realization of compact symplectic algebra provides a natural framework for studying pairing correlations of many-body interactions in nuclei. Here, we use quantum deformation concept in order to describe pairing correlations in atomic nuclei. While the nondeformed limit of the theory provides a reasonable and overall description of certain nuclear properties and fine structure effects, the results show that the q deformation plays a significant role in understanding higher-order effects in the many-body interactions.https://ijpr.iut.ac.ir/article_1082_ff3d96bbcfb99f2220e70de7a7860bfa.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695714220191126A study of the electronic conductance in converting a polyacetylene into polystyrene oligomerA study of the electronic conductance in converting a polyacetylene into polystyrene oligomer2012061083FAHRabaniMMardaniMMardani0000-0002-6268-5311YAlipourJournal Article20191126In this paper, the electronic conductance of a polyacetylene polymer embedded between two simple chains is studied by using transfer matrix method within the tight-binding and first neighbor approach. Also, by adding benzene molecules to polyacetylene we obtain the system conductance in its conversion to polystyrene polymer. The results show that as the number of benzene molecules in the middle of center system increases the conductance in the tunneling area of polyacetylene improves and this area comes close to the resonance area. In contrast, a part of resonance area tends to transform into polystyrene tunneling zone.In this paper, the electronic conductance of a polyacetylene polymer embedded between two simple chains is studied by using transfer matrix method within the tight-binding and first neighbor approach. Also, by adding benzene molecules to polyacetylene we obtain the system conductance in its conversion to polystyrene polymer. The results show that as the number of benzene molecules in the middle of center system increases the conductance in the tunneling area of polyacetylene improves and this area comes close to the resonance area. In contrast, a part of resonance area tends to transform into polystyrene tunneling zone.https://ijpr.iut.ac.ir/article_1083_484b5584db8a51d58bd998283079a5d7.pdf