Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-69577220191126The effect of crystalline and shape anisotropy on the magnetic properties of Co and Ni nanowiresThe effect of crystalline and shape anisotropy on the magnetic properties of Co and Ni nanowires7380568FAR. GolipourA. KhayyatianA. RamazaniM. Almasi KashiJournal Article20191126 Co and Ni magnetic nanowires with different diameter and deposition time were fabricated into the alumina template using ac electrodeposition. For Ni nanowires with 30 nm diameter the coercivity initially increased then dropped with deposition time, while it only increased with deposition time for all the other diameters. In general, the results showed that the coercivity reduced with diameter. The maximum coercivity was obtained for the Co nanowire made with 30 nm diameter and 30 s deposition time and further electrodeposition time causes a reduction of the coercivity. The effect of crystal and shape anisotropy on the magnetic properties were investigated and the results revealed that the crystal anisotropy has a dominant role on the coercive field of Co nanowires, while there is a competitive effect between both the anisotropies for the Ni nanowires changing the coercivity. Co and Ni magnetic nanowires with different diameter and deposition time were fabricated into the alumina template using ac electrodeposition. For Ni nanowires with 30 nm diameter the coercivity initially increased then dropped with deposition time, while it only increased with deposition time for all the other diameters. In general, the results showed that the coercivity reduced with diameter. The maximum coercivity was obtained for the Co nanowire made with 30 nm diameter and 30 s deposition time and further electrodeposition time causes a reduction of the coercivity. The effect of crystal and shape anisotropy on the magnetic properties were investigated and the results revealed that the crystal anisotropy has a dominant role on the coercive field of Co nanowires, while there is a competitive effect between both the anisotropies for the Ni nanowires changing the coercivity.https://ijpr.iut.ac.ir/article_568_e057b0da554be9e67d4e226f8c6bbc4a.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-69577220191126The structural and thermodynamical properties of binary ellipsoidal fluid mixture Gay-Berne interactionThe structural and thermodynamical properties of binary ellipsoidal fluid mixture Gay-Berne interaction8190569FAM. MoradiR. KhordadJournal Article20191126 In this paper, a uniform classical fluid mixture comprising ellipsoidal molecules is studied. This mixture is composed of two types of ellipsoidal molecules interacting through the Gay-Berne potential with different sizes at temperature T. For this system, the Ornstein-Zernike equation using the Percus-Yevick closure relation is solved. Then the direct correlation function, pair correlation function and the pressure of the fluid at temperature T are calculated. The obtained results are in agreement with the previous theories and the results of molecular dynamic computer simulation. In this paper, a uniform classical fluid mixture comprising ellipsoidal molecules is studied. This mixture is composed of two types of ellipsoidal molecules interacting through the Gay-Berne potential with different sizes at temperature T. For this system, the Ornstein-Zernike equation using the Percus-Yevick closure relation is solved. Then the direct correlation function, pair correlation function and the pressure of the fluid at temperature T are calculated. The obtained results are in agreement with the previous theories and the results of molecular dynamic computer simulation.https://ijpr.iut.ac.ir/article_569_0c35c583d8e67b0552b40d707e9deb43.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-69577220191126The mean field study of phase transitions in two dimensional Kagome lattice under local anisotropyThe mean field study of phase transitions in two dimensional Kagome lattice under local anisotropy91100570FAS. MortezapourF. ShahbaziJournal Article20191126 In this work we investigated the critical properties of the anti-ferromagnetic XY model on a two dimensional Kagome lattice under single-ion easy-axes anisotropy. Employing the mean field theory, we found that this model shows a second order phase transition from disordered to all-in all-out state for any value of anisotropy. In this work we investigated the critical properties of the anti-ferromagnetic XY model on a two dimensional Kagome lattice under single-ion easy-axes anisotropy. Employing the mean field theory, we found that this model shows a second order phase transition from disordered to all-in all-out state for any value of anisotropy.https://ijpr.iut.ac.ir/article_570_dc23580f671008df86e6e2e5cd947835.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-69577220191126The self-consistent method in calculating the ratio by using the structure functions and EMC ratios for 3He and 3HThe self-consistent method in calculating the ratio by using the structure functions and EMC ratios for 3He and 3H101105571FAMModarresRMohammadiJournal Article20191126By using the convolution formalism which consists of Fermi motion and binding effect, we investigate the deep inelastic electron scattering from A=3 mirror in the deep-valence region. The initial valence quark input is taken from the GRVs (Gluck, Reya and Vogt) fitting procedure and the next-to-leading order QCD evolution on FP < /sup>2 (x,Q2) which gives very good fit to the available data in the (x,Q2)-plane. It is shown that the free neutron to proton structure function ratios can be extracted from the corresponding EMC ratios for 3He and 3H mirror nuclei using the self - consistent iteration procedure and the results are in good agreement with other theoretical models as well as the current available experimental data and especially the projected data expected from the proposed 11GeV Jefferson Laboratory in near future.By using the convolution formalism which consists of Fermi motion and binding effect, we investigate the deep inelastic electron scattering from A=3 mirror in the deep-valence region. The initial valence quark input is taken from the GRVs (Gluck, Reya and Vogt) fitting procedure and the next-to-leading order QCD evolution on FP < /sup>2 (x,Q2) which gives very good fit to the available data in the (x,Q2)-plane. It is shown that the free neutron to proton structure function ratios can be extracted from the corresponding EMC ratios for 3He and 3H mirror nuclei using the self - consistent iteration procedure and the results are in good agreement with other theoretical models as well as the current available experimental data and especially the projected data expected from the proposed 11GeV Jefferson Laboratory in near future.https://ijpr.iut.ac.ir/article_571_ee5deb635d7da9201421898fe4a09637.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-69577220191126Determining of electron temperature profile on the cross section of a Tokamak, using ECE techniqueDetermining of electron temperature profile on the cross section of a Tokamak, using ECE technique107111572FAM. HosseinpourA. AnvariM. GhorannevisJournal Article20191126 In this paper we have used plasma electron cyclotron emissions at the second harmonic frequency of extraordinary mode to determine the temperature profile of the plasma produced in IR-T1 Tokamak. The emissions obtained at different frequencies by a 5-channel heterodyne receiver, have been analyzed to determine the spatial variation of the electron temperature on the plasma cross section. The results have been also used to show the three-dimensional time evolution of the temperature profile during the period of confinement. In this paper we have used plasma electron cyclotron emissions at the second harmonic frequency of extraordinary mode to determine the temperature profile of the plasma produced in IR-T1 Tokamak. The emissions obtained at different frequencies by a 5-channel heterodyne receiver, have been analyzed to determine the spatial variation of the electron temperature on the plasma cross section. The results have been also used to show the three-dimensional time evolution of the temperature profile during the period of confinement.https://ijpr.iut.ac.ir/article_572_346d05e966ebb39c22cd0652c29a213c.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-69577220191126Multiscale entropy (MSE) and multicomponent complexity (MCC)Multiscale entropy (MSE) and multicomponent complexity (MCC)113118573FAM. BoorboorF. ShahbaziB. MirzaJournal Article20191126Multiscale entropy (MSE) is a powerful method for determining the complexity of random time series. In this paper we, investigate the cardiac heart interbeat interval (RR) time series by introducing a new method based on MSE, called multicomponent complexity (MCC) and find clear difference between healthy samples and samples with Congestive heart failure (CHF) disease.Multiscale entropy (MSE) is a powerful method for determining the complexity of random time series. In this paper we, investigate the cardiac heart interbeat interval (RR) time series by introducing a new method based on MSE, called multicomponent complexity (MCC) and find clear difference between healthy samples and samples with Congestive heart failure (CHF) disease.https://ijpr.iut.ac.ir/article_573_02473058270f6748dcc727fd86b21901.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-69577220191126Barrier and well-width dependence of optical emission of GaN/AlGaN quantum well nanostructuresBarrier and well-width dependence of optical emission of GaN/AlGaN quantum well nanostructures119125574FAH. HaratizadehM. EsmaeiliP. O. HoltzJournal Article20191126Internal polarizations field which take place in quantum structures of group-III nitrides have an important consequence on their optical properties. Optical properties of wurtzite AlGaN/GaN quantum well (QW) structures grown by MBE and MOCVD on c-plane sapphire substrates have been investigated by means of photoluminescence (PL) and time resolved photoluminescence (TRPL) at low-temperature. PL spectra exhibit a blue-shifted emission of AlGaN/GaN quantum well (QW) nanostructures by decreasing the barrier width contrary to the arsenide system. The trend of the barrier-width dependence of the internal polarization field is reproduced by using simple electrostatic arguments. In addition the effect of well width variation on the optical transition and decay time of GaN MQWs have been investigated and it has been shown that the screening of the piezoelectric field and the electron-hole separation are strongly dependent on the well thickness and have a profound effect on the optical properties of the GaN/AlGaN MQWs.Internal polarizations field which take place in quantum structures of group-III nitrides have an important consequence on their optical properties. Optical properties of wurtzite AlGaN/GaN quantum well (QW) structures grown by MBE and MOCVD on c-plane sapphire substrates have been investigated by means of photoluminescence (PL) and time resolved photoluminescence (TRPL) at low-temperature. PL spectra exhibit a blue-shifted emission of AlGaN/GaN quantum well (QW) nanostructures by decreasing the barrier width contrary to the arsenide system. The trend of the barrier-width dependence of the internal polarization field is reproduced by using simple electrostatic arguments. In addition the effect of well width variation on the optical transition and decay time of GaN MQWs have been investigated and it has been shown that the screening of the piezoelectric field and the electron-hole separation are strongly dependent on the well thickness and have a profound effect on the optical properties of the GaN/AlGaN MQWs.https://ijpr.iut.ac.ir/article_574_d7b7a88c46034d5c84004b733d629ac9.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-69577220191126Hypercentral constituent quark model and the hyperfine dependence potentialHypercentral constituent quark model and the hyperfine dependence potential127127575FAM. R.ShojaeiA. A.RajabiJournal Article20191126 In this article nucleons are discussed based on constituent quark model. This model aims at studying the forces among three particles and the corresponding standard two-body potential contribution. The quark potential contains a hypercentral interaction. The confining potential is composed of four components,color charge, the oscillatory potential, the interaction quark and neutral gluon, and the dipole – dipole electromagnetic interaction. Dirac equation can be solved carefully and analytically by means of these potentials. In addition to the above potentials, there is a hyperfine potential which is related to isospin – isospin and spin –isopin interactions. These potentials were considered as perturbation potentials and their energy shift was calculated. In this article nucleons are discussed based on constituent quark model. This model aims at studying the forces among three particles and the corresponding standard two-body potential contribution. The quark potential contains a hypercentral interaction. The confining potential is composed of four components,color charge, the oscillatory potential, the interaction quark and neutral gluon, and the dipole – dipole electromagnetic interaction. Dirac equation can be solved carefully and analytically by means of these potentials. In addition to the above potentials, there is a hyperfine potential which is related to isospin – isospin and spin –isopin interactions. These potentials were considered as perturbation potentials and their energy shift was calculated.https://ijpr.iut.ac.ir/article_575_ec2d225dce37c263f3b5ababc1622067.pdfIsfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-69577220191126Quantum averaging and resonances: two-level atom in a one-mode classical laser fieldQuantum averaging and resonances: two-level atom in a one-mode classical laser field128128576FAM. Amniat-TalabH. SedghiR. Khoda-BakhshJournal Article20191126 We use a nonperturbative method based on quantum averaging and an adapted from of resonant transformations to treat the resonances of the Hamiltonian of a two-level atom interacting with a one-mode classical field in Floquet formalism. We illustrate this method by extraction of effective Hamiltonians of the system in two regimes of weak and strong coupling. The results obtained in the strong-coupling regime, are valid in the whole range of the coupling constant for the one-photon zero-field resonance. We use a nonperturbative method based on quantum averaging and an adapted from of resonant transformations to treat the resonances of the Hamiltonian of a two-level atom interacting with a one-mode classical field in Floquet formalism. We illustrate this method by extraction of effective Hamiltonians of the system in two regimes of weak and strong coupling. The results obtained in the strong-coupling regime, are valid in the whole range of the coupling constant for the one-photon zero-field resonance.https://ijpr.iut.ac.ir/article_576_02437fd2f212489efe173a272e1230fe.pdf