The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Spin transfer torque in graphene-based domain walls Spin transfer torque in graphene-based domain walls 47 52 3432 10.47176/ijpr.22.3.11599 FA Zeinab Rashidian Faculty of Science, Department of Physics, Lorestan University, Khoramabad 68151-44316, Iran Khadije Jahanbani Department of Materials Science and Engineering, School of Engineering, Meybod University, P.O.Box 89616-99557, Yazd, Iran Journal Article 2022 11 09 Scattering matrix formalism is employed to calculate the spin transfer torque in a graphene-based domain wall (DW) in the ballistic regime. We have suggested a new method for manipulating the direction of domain wall motion by both the length of the DW and magnetic barrier that is the ratio of induced exchange field to Fermi energy. It has also shown that spin current density gives us more insight into the transmission of spin-polarized electrons. Scattering matrix formalism is employed to calculate the spin transfer torque in a graphene-based domain wall (DW) in the ballistic regime. We have suggested a new method for manipulating the direction of domain wall motion by both the length of the DW and magnetic barrier that is the ratio of induced exchange field to Fermi energy. It has also shown that spin current density gives us more insight into the transmission of spin-polarized electrons. https://ijpr.iut.ac.ir/article_3432_72007983849f4fcb0ad565439834756b.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Formation of self-organized TiO2 nanotube arrays and its photoelectrochemical response Formation of self-organized TiO2 nanotube arrays and its photoelectrochemical response 53 57 3429 10.47176/ijpr.23.3.61475 FA Hawraa Sabah Hreo Department of Physics, College of Education, University of Al-Qadisiyah, Al-Diwaniyah, Al-Qadisiyah 58002, Iraq Araa Mebdir Holi Department of Physics, College of Education, University of Al-Qadisiyah, Al-Diwaniyah, Al-Qadisiyah 58002, Iraq Asma Kadim Ayal Department of Chemistry, College of Science for Women, University of Baghdad, Baghdad, Iraq Journal Article 2022 06 23 In this study, TiO₂ nanotube arrays (TNTAs) are produced using an efficient, low-cost, and ecofriendly environmental anodization process in an electrolyte containing Glycerin. The TNTAs were annealed for 2 hours at 500 °C. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), UV-Vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL), and photoelectrochemical properties (PEC) were used to analyze the sample. According to the obtained findings, the photoelectrochemical response of the TiO₂ film was accomplished with a current density (J_ph) of 0.196 mAcm^-2 and photoconversion efficiency of 0.14 %. In this study, TiO₂ nanotube arrays (TNTAs) are produced using an efficient, low-cost, and ecofriendly environmental anodization process in an electrolyte containing Glycerin. The TNTAs were annealed for 2 hours at 500 °C. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), UV-Vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL), and photoelectrochemical properties (PEC) were used to analyze the sample. According to the obtained findings, the photoelectrochemical response of the TiO₂ film was accomplished with a current density (J_ph) of 0.196 mAcm^-2 and photoconversion efficiency of 0.14 %. https://ijpr.iut.ac.ir/article_3429_caa202034f268232c26fac9435f54e15.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Enhance hydrogen sulfide (H2S) gas sensor based on metal oxide semiconductor (NiO) thin films Enhance hydrogen sulfide (H2S) gas sensor based on metal oxide semiconductor (NiO) thin films 59 65 3433 10.47176/ijpr.23.3.71530 FA Radhiyah M Aljarrah Department of Physics, Faculty of Science, Kufa University, Najaf, Iraq 0000-0003-3431-4238 Nawar Rahim Department of Physics, Faculty of Science, Kufa University, Najaf, Iraq Journal Article 2022 07 18 The morphological and structural properties of NiO films have been studied to find out the possibility of exploit (exploiting) it as a gas sensor. The thin film of the nickel oxide has been obtained by a chemical spray pyrolysis technique on glass substrates using various concentrations of nickel nitrate hexahydrate [Ni(NO₃)₂:6H₂O] aqueous solution. The produced films were characterized using X-Ray diffraction and atomic force microscopy. The investigations revealed that the crystal structure are a cubic polycrystalline with preferential orientation along the (111) plane. The topographical analyse (AFM) shows that the values of the grain size increasing with increase the concentration, where average of the grain diameter raised from 42.04-110.058 nm of 0.01 M  and  0.1M concentrations respectively. The gas sensing results demonstrate that sensitivity of nickel  oxide semiconductor films to the hydrogen sulfide gas are affected by the size of the growing crystallites and the operating temperature. The morphological and structural properties of NiO films have been studied to find out the possibility of exploit (exploiting) it as a gas sensor. The thin film of the nickel oxide has been obtained by a chemical spray pyrolysis technique on glass substrates using various concentrations of nickel nitrate hexahydrate [Ni(NO₃)₂:6H₂O] aqueous solution. The produced films were characterized using X-Ray diffraction and atomic force microscopy. The investigations revealed that the crystal structure are a cubic polycrystalline with preferential orientation along the (111) plane. The topographical analyse (AFM) shows that the values of the grain size increasing with increase the concentration, where average of the grain diameter raised from 42.04-110.058 nm of 0.01 M  and  0.1M concentrations respectively. The gas sensing results demonstrate that sensitivity of nickel  oxide semiconductor films to the hydrogen sulfide gas are affected by the size of the growing crystallites and the operating temperature. https://ijpr.iut.ac.ir/article_3433_a91af177d3016ca20e5fc949836a894a.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Optical and thermochromic properties of yttrium iron garnet paint Optical and thermochromic properties of yttrium iron garnet paint 67 73 3434 10.47176/ijpr.23.3.81544 FA Ali Rostamnejadi Faulty of Electromagnetics, Malek Ashtar University of Technology, Iran Mohammad Madahi Harandi Faulty of Electromagnetics, Malek Ashtar University of Technology, Iran Mohammad Jazirehpour Faulty of Electromagnetics, Malek Ashtar University of Technology, Iran Journal Article 2022 08 04 In this study, we have investigated the optical and high-temperature thermochromic properties of yttrium iron garnet powder and paint. The powders were produced using the solid-state reaction technique, and the thermochromic paint was sprayed over an Al alloy substrate. X-ray diffraction patterns, optical and field emission scanning electron microscopes, and UV-Vis and FTIR spectrophotometers were used to assess the structural, surface morphology and optical characteristics of the materials. The thermochromic characteristics of the samples were investigated by extracting the chromatic coordinates L*b*a* from digital pictures taken at temperatures ranging from 25 to 210 °C. The results reveal that when the temperature rises, the color of the paint changes from dark green to dark brown. The charge transfer between oxygen and iron ions, as well as the electron transition across the orbitals of the d layer, could be responsible for the observed reversible color change. The paint has strong thermal stability up to 350 °C which is suitable for high-temperature thermochromic applications. In this study, we have investigated the optical and high-temperature thermochromic properties of yttrium iron garnet powder and paint. The powders were produced using the solid-state reaction technique, and the thermochromic paint was sprayed over an Al alloy substrate. X-ray diffraction patterns, optical and field emission scanning electron microscopes, and UV-Vis and FTIR spectrophotometers were used to assess the structural, surface morphology and optical characteristics of the materials. The thermochromic characteristics of the samples were investigated by extracting the chromatic coordinates L*b*a* from digital pictures taken at temperatures ranging from 25 to 210 °C. The results reveal that when the temperature rises, the color of the paint changes from dark green to dark brown. The charge transfer between oxygen and iron ions, as well as the electron transition across the orbitals of the d layer, could be responsible for the observed reversible color change. The paint has strong thermal stability up to 350 °C which is suitable for high-temperature thermochromic applications. https://ijpr.iut.ac.ir/article_3434_14c879f3f5d8ed93a09f6090d77c2cc3.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Entanglement amplification by three-level laser coupled to vacuum reservoir Entanglement amplification by three-level laser coupled to vacuum reservoir 75 84 3421 10.47176/ijpr.23.3.31660 FA Menisha Alemu Department of Physics, Wolkite University, Ethiopia 0000-0003-2419-0294 Fekadu Tolessa Adama Science and Technology University, P. O. Box 07, Wolkite, Ethiopia Birke Alemu Adama Science and Technology University, P. O. Box 07, Wolkite, Ethiopia Journal Article 2023 03 17 In this paper we have studied the squeezing and entanglement properties of the cavity light generated by a three-level laser. In this quantum optical system, N three-level atoms available in an open cavity, coupled to a two-mode vacuum reservoir, are pumped to the top level by means of electron bombardment at constant rate. Applying the solutions of the equations of evolution for the expectation values of the atomic operators and the quantum Langevin equations for the cavity mode operators, we have calculated the mean, variance of the photon number, the quadrature squeezing, entanglement amplification as well as the normalized second-order correlation function for the cavity light. In addition, we have shown that the presence of the spontaneous emission process leads to a decrease in the mean and variance of the photon number. We have observed that the two-mode cavity light is in a squeezed state and the squeezing occurs in the minus quadrature. In addition, we have found that the effect of the vacuum reservoir noise is to increase the photon-number variance and to decrease the quadrature squeezing of the cavity light. However, the vacuum reservoir noise does not have any effect on the mean photon number. Moreover, the maximum quadrature squeezing of the light generated by the laser, operating far below threshold, is found to be  below the vacuum-state level. In addition, our result indicates that the quadrature squeezing is greater for  than that for  for 0.01 <   < 0.35 and is smaller for  than that for  for 0.35 <  < 1. We have also noted that the squeezing and entanglement in the two-mode light are directly related. As a result, an increase in the degree of squeezing directly leads to an increase in the degree of entanglement and vice versa. This shows that, whenever there is squeezing in the two-mode light, there exists an entanglement in the system. In this paper we have studied the squeezing and entanglement properties of the cavity light generated by a three-level laser. In this quantum optical system, N three-level atoms available in an open cavity, coupled to a two-mode vacuum reservoir, are pumped to the top level by means of electron bombardment at constant rate. Applying the solutions of the equations of evolution for the expectation values of the atomic operators and the quantum Langevin equations for the cavity mode operators, we have calculated the mean, variance of the photon number, the quadrature squeezing, entanglement amplification as well as the normalized second-order correlation function for the cavity light. In addition, we have shown that the presence of the spontaneous emission process leads to a decrease in the mean and variance of the photon number. We have observed that the two-mode cavity light is in a squeezed state and the squeezing occurs in the minus quadrature. In addition, we have found that the effect of the vacuum reservoir noise is to increase the photon-number variance and to decrease the quadrature squeezing of the cavity light. However, the vacuum reservoir noise does not have any effect on the mean photon number. Moreover, the maximum quadrature squeezing of the light generated by the laser, operating far below threshold, is found to be  below the vacuum-state level. In addition, our result indicates that the quadrature squeezing is greater for  than that for  for 0.01 <   < 0.35 and is smaller for  than that for  for 0.35 <  < 1. We have also noted that the squeezing and entanglement in the two-mode light are directly related. As a result, an increase in the degree of squeezing directly leads to an increase in the degree of entanglement and vice versa. This shows that, whenever there is squeezing in the two-mode light, there exists an entanglement in the system. https://ijpr.iut.ac.ir/article_3421_e846fb8a4f365ca8e84393d4f34e1b07.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Ni doped ZnO nanorod/glass prepared by chemical bath deposition Ni doped ZnO nanorod/glass prepared by chemical bath deposition 85 88 3426 10.47176/ijpr.23.3.61487 FA Hadeel Abdulrahman Department of Physics,College of Science, University of Kufa Hussein Alshemirti Department of Physics,College of Science, University of Kufa Journal Article 2022 06 24 In this paper, Ni-doped ZnO nanorods (NRs) with concentrations of (0%, 1%, 2%, and 4%) were successfully grown on glass slides by Chemical bath deposition CBD at (85-90) °C. X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), and UV- Vis spectrum were performed to characterize the prepared films. The results of the X-ray diffraction measurements of the samples showed that all the prepared films were of a crystalline structure of the hexagonal type with the dominance of growth in the (002) direction and a decrease in the intensity of the peak characteristic with increased Ni-doped. The FESEM images show the average diameters of ZnO NRs, Ni (1%) NRs, Ni (2%) NRs and Ni (4%) NRs, there is a clear increase in the rate of the average diameters by increasing the percentage of doping. The band gap of seed layers ZnO and undoped ZnO nanorods /glass was found to be 3.25 eV and 3.2 eV respectively. The values of the optical energy gap of Ni-doped ZnO are about (3.12, 3.09, 3) eV with an increase in the rate of doping. The results of the optical and structure measurements also included calculating parameters micro strain (ε), about the Ni doped ZnO (0%, 1%, 2%, and 4%) films for (100), (002), and (101). In this paper, Ni-doped ZnO nanorods (NRs) with concentrations of (0%, 1%, 2%, and 4%) were successfully grown on glass slides by Chemical bath deposition CBD at (85-90) °C. X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), and UV- Vis spectrum were performed to characterize the prepared films. The results of the X-ray diffraction measurements of the samples showed that all the prepared films were of a crystalline structure of the hexagonal type with the dominance of growth in the (002) direction and a decrease in the intensity of the peak characteristic with increased Ni-doped. The FESEM images show the average diameters of ZnO NRs, Ni (1%) NRs, Ni (2%) NRs and Ni (4%) NRs, there is a clear increase in the rate of the average diameters by increasing the percentage of doping. The band gap of seed layers ZnO and undoped ZnO nanorods /glass was found to be 3.25 eV and 3.2 eV respectively. The values of the optical energy gap of Ni-doped ZnO are about (3.12, 3.09, 3) eV with an increase in the rate of doping. The results of the optical and structure measurements also included calculating parameters micro strain (ε), about the Ni doped ZnO (0%, 1%, 2%, and 4%) films for (100), (002), and (101). https://ijpr.iut.ac.ir/article_3426_5d2c2cee8ab0b9a36bd1ed7196bd6c4a.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Enhancement of spontaneous emission and material gain from CdSe/CdS quantum dot Enhancement of spontaneous emission and material gain from CdSe/CdS quantum dot 89 93 3427 10.47176/ijpr.22.3.61501 FA Jamal Jabir Physics Department ,College of Education , University of Al-Qadisiyah , Diwaniyah , Iraq Ghadeer Kadhim Physics Department ,College of Education , University of Al-Qadisiyah , Diwaniyah , Iraq Journal Article 2022 06 27 This study looks at the material gain and enhanced spontaneous emission of CdSe(1-x)S(x)/ZnS and CdSe(1-x)S(x)/ZnO quantum dot (QD) structures. (remove dot) cadmium selenide (CdSe) QDs, cadmium sulfide (CdS) wetting layer (WL), zinc oxide (ZnO) and zinc sulfide (ZnS) as a barrier layers were investigated to achieve QDs semiconductor with active region (B). The energy levels and band alignment between layers are predicted using the quantum disk model. Gain is an estimation for the transverse electric (TE) and magnetic (TM) modes in QDs structures, taking into consideration the momentum matrix element. The mole-fraction (x) and contributions of the barriers (ZnO and ZnS) material in enhanced gain and spontaneous emission were investigated in this manuscript. When ZnS is used as a barrier material, the spontaneous emission is found to be 11.75×10^19 (eV.sec.cm^3 )^(-1) at x~0.69 and wavelength 324 nm, and the material gain has maximum values of order 5.671×10^4 cm^(-2) for TM and 3.743×10^7for TE modes, respectively. Whenever the barrier is changed to ZnO, the results are different; at x~0.438 and wavelength 365 nm, the spontaneous emission becomes 2.965×10^19 (eV.sec.cm^3 )^(-1) and the gain has maximum values of order 2.118×10^4 cm^(-2) for TM and 1.242×10^5 cm^(-2)for TE mode. This study looks at the material gain and enhanced spontaneous emission of CdSe(1-x)S(x)/ZnS and CdSe(1-x)S(x)/ZnO quantum dot (QD) structures. (remove dot) cadmium selenide (CdSe) QDs, cadmium sulfide (CdS) wetting layer (WL), zinc oxide (ZnO) and zinc sulfide (ZnS) as a barrier layers were investigated to achieve QDs semiconductor with active region (B). The energy levels and band alignment between layers are predicted using the quantum disk model. Gain is an estimation for the transverse electric (TE) and magnetic (TM) modes in QDs structures, taking into consideration the momentum matrix element. The mole-fraction (x) and contributions of the barriers (ZnO and ZnS) material in enhanced gain and spontaneous emission were investigated in this manuscript. When ZnS is used as a barrier material, the spontaneous emission is found to be 11.75×10^19 (eV.sec.cm^3 )^(-1) at x~0.69 and wavelength 324 nm, and the material gain has maximum values of order 5.671×10^4 cm^(-2) for TM and 3.743×10^7for TE modes, respectively. Whenever the barrier is changed to ZnO, the results are different; at x~0.438 and wavelength 365 nm, the spontaneous emission becomes 2.965×10^19 (eV.sec.cm^3 )^(-1) and the gain has maximum values of order 2.118×10^4 cm^(-2) for TM and 1.242×10^5 cm^(-2)for TE mode. https://ijpr.iut.ac.ir/article_3427_5421e013565f7f1afa0cfe8ad87a99ab.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Pressure induced structural phase transition and influence of pressure on the electronic and mechanical properties of TiPdSn: an ab initio study Pressure induced structural phase transition and influence of pressure on the electronic and mechanical properties of TiPdSn: an ab initio study 95 100 3422 10.47176/ijpr.23.3.41671 FA Omamoke O E Enaroseha Department of Physics, Delta State University Abraka, Nigeria 0000-0002-5387-2908 Michael Babalola Department of Physics, University of Benin, Nigeria Journal Article 2023 04 06 Structural, electronic, mechanical and optical properties of half-Heusler alloy TiPdSn were investigated from first-principles calculation as well as the structural phase transition under pressure.  The projected augmented wave (PAW) type of pseudopotential within the generalized gradient approximation (GGA) was used during the calculation. The obtained results revealed that TiPdSn is a semiconductor with an indirect band gap.  Also the results from the mechanical property showed that TiPdSn is ductile and mechanically stable. TiPdSn is seen to undergo structural phase transition from cubic to two different structures namely type1 and type2 which crystallize in  hexagonal structure and the transition pressures recorded were 4.53GPa for type 1 and 25.3 GPa for type 2. Optical properties revealed that TiPdSn has a static dielectric function of 21.47 and a refractive index of 4.63. The band gap of the alloy decreases and later increases as pressure increases. Structural, electronic, mechanical and optical properties of half-Heusler alloy TiPdSn were investigated from first-principles calculation as well as the structural phase transition under pressure.  The projected augmented wave (PAW) type of pseudopotential within the generalized gradient approximation (GGA) was used during the calculation. The obtained results revealed that TiPdSn is a semiconductor with an indirect band gap.  Also the results from the mechanical property showed that TiPdSn is ductile and mechanically stable. TiPdSn is seen to undergo structural phase transition from cubic to two different structures namely type1 and type2 which crystallize in  hexagonal structure and the transition pressures recorded were 4.53GPa for type 1 and 25.3 GPa for type 2. Optical properties revealed that TiPdSn has a static dielectric function of 21.47 and a refractive index of 4.63. The band gap of the alloy decreases and later increases as pressure increases. https://ijpr.iut.ac.ir/article_3422_73640de25b7d656733ce2f808a330f18.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Gravitational collapse of the galactic dark matter Gravitational collapse of the galactic dark matter 101 106 3435 10.47176/ijpr.23.3.11596 FA Elham Farhadi Faculty of Physics, Department of Fundamental Physics, University of Alzahra, Tehran, Iran Ahmad Shariati Faculty of Physics, Department of Fundamental Physics, University of Alzahra, Tehran, Iran 0000-0002-8090-9905 Journal Article 2022 11 09 A spherically symmetric matter collapses under its own gravity. For the Milky Way, the time scale of collapse for a spherical halo with NFW density is ∼ 26 My which is very small compared to the age of the Milky Way. The effect of a pressure, obeying a polytrope equation of state is investigated. It is shown that for p ∝ ρ^9/8,  the time scale would be of the order of 1 Gy. It is also argued that such a polytrope, if considered to be in equilibrium, could explain the rotation curve of the milky way. A spherically symmetric matter collapses under its own gravity. For the Milky Way, the time scale of collapse for a spherical halo with NFW density is ∼ 26 My which is very small compared to the age of the Milky Way. The effect of a pressure, obeying a polytrope equation of state is investigated. It is shown that for p ∝ ρ^9/8,  the time scale would be of the order of 1 Gy. It is also argued that such a polytrope, if considered to be in equilibrium, could explain the rotation curve of the milky way. https://ijpr.iut.ac.ir/article_3435_5b970a1d9be0fd100063fd6cd688b73e.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Graphitic carbon nitride/MIL-88B(Fe) nanocomposite for methylene blue dye removal from aqueous solution by UV-visible light active photo-Fenton Reaction Graphitic carbon nitride/MIL-88B(Fe) nanocomposite for methylene blue dye removal from aqueous solution by UV-visible light active photo-Fenton Reaction 107 114 3430 10.47176/ijpr.23.3.11632 FA Sediqa Alijani College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran Amene Naseri Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education, and Extension Organization (AREEO), Karaj, 3135933151, Iran 0000-0003-3102-8906 Amir Hossein Hamidian College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran Journal Article 2023 01 16 In the present research, g-C₃N₄/MIL-88B(Fe) nanocomposite photocatalyst was successfully synthesized by the solvothermal method. The morphology, crystal structure, chemical functionalities, and optical properties of the obtained nanocomposite were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and UV-Vis diffuse reflectance spectroscopy (DRS), respectively. According to the SEM and TEM images, spindle-shaped MIL-88B(Fe) nanostructures were synthesized with an average length and width of 2 and 1 μm, respectively. Furthermore, g-C₃N₄ nanoparticles with an average diameter of 30 nm were observed on the surface of the MIL-88B(Fe). Based on the XRD results, the presence of both g-C₃N₄ and MIL-88B(Fe) nanostructures in the prepared composite was confirmed. Also, the presence of functional groups of the MIL-88B(Fe) and g-C₃N₄ was determined by FTIR. Based on DRS analysis and Tauc's plot, the band gap energy of the prepared composite was measured as 2.1 eV, which indicated that the prepared composite could absorb light in the visible region. The degradation of organic pollutant methylene blue (MB) in the g-C₃N₄/MIL- 88B(Fe)+light+H₂O₂ system was investigated to evaluate the photo-Fenton activity of the prepared composite in comparison with light and light+H₂O₂ systems. The results showed that the presence of g-C₃N₄/MIL-88B(Fe) composite increased the degradation rate of MB pollutant under the photo-Fenton process by 8.1 and 2.8 times higher than the mentioned systems, respectively. Thus, MB removal efficiency reached 100% within 20 min of illumination. The superiority of the g-C₃N₄/MIL-88B(Fe)+light+H₂O₂ system can be attributed to the retardation of electron-hole recombination due to the presence of two nanostructures of g-C₃N₄ and MIL-88B(Fe) in heterojunction, which has led to an increase in the efficiency of the photo-Fenton reaction. In the present research, g-C₃N₄/MIL-88B(Fe) nanocomposite photocatalyst was successfully synthesized by the solvothermal method. The morphology, crystal structure, chemical functionalities, and optical properties of the obtained nanocomposite were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and UV-Vis diffuse reflectance spectroscopy (DRS), respectively. According to the SEM and TEM images, spindle-shaped MIL-88B(Fe) nanostructures were synthesized with an average length and width of 2 and 1 μm, respectively. Furthermore, g-C₃N₄ nanoparticles with an average diameter of 30 nm were observed on the surface of the MIL-88B(Fe). Based on the XRD results, the presence of both g-C₃N₄ and MIL-88B(Fe) nanostructures in the prepared composite was confirmed. Also, the presence of functional groups of the MIL-88B(Fe) and g-C₃N₄ was determined by FTIR. Based on DRS analysis and Tauc's plot, the band gap energy of the prepared composite was measured as 2.1 eV, which indicated that the prepared composite could absorb light in the visible region. The degradation of organic pollutant methylene blue (MB) in the g-C₃N₄/MIL- 88B(Fe)+light+H₂O₂ system was investigated to evaluate the photo-Fenton activity of the prepared composite in comparison with light and light+H₂O₂ systems. The results showed that the presence of g-C₃N₄/MIL-88B(Fe) composite increased the degradation rate of MB pollutant under the photo-Fenton process by 8.1 and 2.8 times higher than the mentioned systems, respectively. Thus, MB removal efficiency reached 100% within 20 min of illumination. The superiority of the g-C₃N₄/MIL-88B(Fe)+light+H₂O₂ system can be attributed to the retardation of electron-hole recombination due to the presence of two nanostructures of g-C₃N₄ and MIL-88B(Fe) in heterojunction, which has led to an increase in the efficiency of the photo-Fenton reaction. https://ijpr.iut.ac.ir/article_3430_2d2c8394e31101a261abf1784302bf75.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Quantum key distribution in computer networks Quantum key distribution in computer networks 115 121 3420 10.47176/ijpr.23.3.51684 FA Maedeh Abbasi Faculty of Physics, Alzahra University, Tehran, Iran Ahmad Shariati Faculty of Physics, Alzahra University, Tehran, Iran 0000-0002-8090-9905 Reza Mohammadi Department of Computer Engineering, Bu-Ali Sina University, Hamedan, Iran Journal Article 2023 05 14 The secure transfer of keys between two parties, is one of the primary problems in cryptography. The possibility that the key can be manipulated or intercepted by way of an eavesdropper is the cause for the concern. A promising way to this problem is Quantum Key Distribution (QKD). The secure distribution of keys that may be used to encrypt and decrypt messages is made feasible by this approach, which makes use of the idea of quantum mechanics. QKD offers a degree of protection that can not be done by means of classical cryptography techniques, and has remarkable capability for application in a scope of fields in which secure correspondence is crucial. QKD is a field of study that has brought various conventions pointed toward empowering the safe alternate of cryptographic keys between two parties, Alice and Bob. Two key protocols within this field are the BB84 which was designed by Bennett and Brassard and E91 which was proposed by Ekert. While other protocols have been developed, many draw inspiration from these two foundational approaches. We focused specifically on the E91 protocol and explored its potential for the safe transfer of entangled pairs within computer networks. This protocol utilizes entanglement between particles as a means of verifying the security of the key exchange. Our investigation centered around testing the entanglement swapping for two particles using the E91 protocol, with the aim of developing a novel method for the secure transmission of entangled pairs via computer networks. Our findings suggest promising avenues for future work in implementing secure entanglement swapping in practical applications. The secure transfer of keys between two parties, is one of the primary problems in cryptography. The possibility that the key can be manipulated or intercepted by way of an eavesdropper is the cause for the concern. A promising way to this problem is Quantum Key Distribution (QKD). The secure distribution of keys that may be used to encrypt and decrypt messages is made feasible by this approach, which makes use of the idea of quantum mechanics. QKD offers a degree of protection that can not be done by means of classical cryptography techniques, and has remarkable capability for application in a scope of fields in which secure correspondence is crucial. QKD is a field of study that has brought various conventions pointed toward empowering the safe alternate of cryptographic keys between two parties, Alice and Bob. Two key protocols within this field are the BB84 which was designed by Bennett and Brassard and E91 which was proposed by Ekert. While other protocols have been developed, many draw inspiration from these two foundational approaches. We focused specifically on the E91 protocol and explored its potential for the safe transfer of entangled pairs within computer networks. This protocol utilizes entanglement between particles as a means of verifying the security of the key exchange. Our investigation centered around testing the entanglement swapping for two particles using the E91 protocol, with the aim of developing a novel method for the secure transmission of entangled pairs via computer networks. Our findings suggest promising avenues for future work in implementing secure entanglement swapping in practical applications. https://ijpr.iut.ac.ir/article_3420_643de7cf7ba769c7466ccbc4adfd7fac.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Investigation of ultra-high energy cosmic ray mass composition by the ground based detectors Investigation of ultra-high energy cosmic ray mass composition by the ground based detectors 123 127 3424 10.47176/ijpr.23.3.71726 FA Saeed Doostmohammadi Faculty of Physics, Shahid Bahonar University of Kerman, Kerman, Iran 0000-0001-9616-0428 Journal Article 2023 07 16 Mass composition of cosmic rays and thus determining their sources, especially at high energies, is one of the most important parts of astroparticle physics and cosmic ray science which also can help to know the universe better. Many different methods have been used to estimate the mass composition so far, which the most important of them has been done by Pierre Auger observatory group. In present work, in order to estimate the mass composition of cosmic rays, two different ways (first using from muonic component and second, maximum atmospheric depth) are used which they have been done by comparing experimental data and simulated ones. An increase in the mass composition and low flux of photons is observed at high energies. The diagram of maximum atmospheric depth in terms of energy, which is produced by extrapolation and interpolation statistical method, raises and falls meaningfully that is compatible to the results of Pierre Auger observatory. At higher energies, the percentage of primary particles have a tendency to heavier particles and in low energies the primary particles are lighter. Also, the most important breaks in the energy spectrum of cosmic rays are seen. Mass composition of cosmic rays and thus determining their sources, especially at high energies, is one of the most important parts of astroparticle physics and cosmic ray science which also can help to know the universe better. Many different methods have been used to estimate the mass composition so far, which the most important of them has been done by Pierre Auger observatory group. In present work, in order to estimate the mass composition of cosmic rays, two different ways (first using from muonic component and second, maximum atmospheric depth) are used which they have been done by comparing experimental data and simulated ones. An increase in the mass composition and low flux of photons is observed at high energies. The diagram of maximum atmospheric depth in terms of energy, which is produced by extrapolation and interpolation statistical method, raises and falls meaningfully that is compatible to the results of Pierre Auger observatory. At higher energies, the percentage of primary particles have a tendency to heavier particles and in low energies the primary particles are lighter. Also, the most important breaks in the energy spectrum of cosmic rays are seen. https://ijpr.iut.ac.ir/article_3424_71a5c0514ab83382d98154e5a5f9d813.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 String Cosmological Model in 5-Dimensional Space-Time: Interacting with viscous Fluid String Cosmological Model in 5-Dimensional Space-Time: Interacting with viscous Fluid 129 133 3423 10.47176/ijpr.23.3.81736 FA Jiten Baro Kamrup College, Chamata, Nalbari, India Kangujam Priyokumar Singh 2. Department of Mathematics, Manipur University, Imphal-795003, Manipur, India Journal Article 2023 08 10 Considering bulk viscosity as (i) constant quantity and (ii) functions of cosmic time, the field equations in 5-dimensional Bianchi type-I model in the context of general theory of relativity, has been obtained and solved in this paper by the use of certain physical assumptions, which are agreeing with the present observational findings. In both cases, the model represents an exponentially expanding and accelerating Universe that starts with volume 0 and stops with infinite volume. The model has an initial singularity and will eventually approach the de-Sitter phase ( ). It also satisfies the energy conditions  and . This model represents a matter-dominated Universe that agrees with current observational data. The model is anisotropic one and shearing throughout its evolution for .<br />Considering bulk viscosity as (i) constant quantity and (ii) functions of cosmic time, the field equations in 5-dimensional Bianchi type-I model in the context of general theory of relativity, has been obtained and solved in this paper by the use of certain physical assumptions, which are agreeing with the present observational findings. In both cases, the model represents an exponentially expanding and accelerating Universe that starts with volume 0 and stops with infinite volume. The model has an initial singularity and will eventually approach the de-Sitter phase ( ). It also satisfies the energy conditions  and . This model represents a matter-dominated Universe that agrees with current observational data. The model is anisotropic one and shearing throughout its evolution for . Considering bulk viscosity as (i) constant quantity and (ii) functions of cosmic time, the field equations in 5-dimensional Bianchi type-I model in the context of general theory of relativity, has been obtained and solved in this paper by the use of certain physical assumptions, which are agreeing with the present observational findings. In both cases, the model represents an exponentially expanding and accelerating Universe that starts with volume 0 and stops with infinite volume. The model has an initial singularity and will eventually approach the de-Sitter phase ( ). It also satisfies the energy conditions  and . This model represents a matter-dominated Universe that agrees with current observational data. The model is anisotropic one and shearing throughout its evolution for .<br />Considering bulk viscosity as (i) constant quantity and (ii) functions of cosmic time, the field equations in 5-dimensional Bianchi type-I model in the context of general theory of relativity, has been obtained and solved in this paper by the use of certain physical assumptions, which are agreeing with the present observational findings. In both cases, the model represents an exponentially expanding and accelerating Universe that starts with volume 0 and stops with infinite volume. The model has an initial singularity and will eventually approach the de-Sitter phase ( ). It also satisfies the energy conditions  and . This model represents a matter-dominated Universe that agrees with current observational data. The model is anisotropic one and shearing throughout its evolution for . https://ijpr.iut.ac.ir/article_3423_3d324c2883882b15fa8fbe8f025a3a99.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Synthesis and examination of new PVA-Fe2O3-Au hybrid composite Synthesis and examination of new PVA-Fe2O3-Au hybrid composite 135 139 3425 10.47176/ijpr.23.3.41674 FA Kahtan A. Mohammed Department of Medical Physics,Faculty of Medical Sciences, Jabir Ibn Hayyan Medical University, Najaf, 54001, Iraq Alyaa Abdul Hasan Abdul Kareem Department of chemistry and polymer research, polymer research center, University of Basrah, Basrah, Iraq Hawraa K. Judi 3. Department of medical physics, Hilla University College, Babylon, Iraq Athota Rathan Department of Aeronautical engineering, Institute of Aeronautical, Hyderabad, Telangana, India Sameer Algburi Computer Engineering Techniques Department, College of Engineering Techniques, Al-Kitab University, Altun Kupri, Kirkuk, Iraq Mohammed Ayad Alkhafaji National University of Science and Technology, Dhi Qar, Iraq Rahman S. Zabibah Medical Laboratory Technology Department, College of Medical Technology, the Islamic University, Najaf, Iraq Journal Article 2023 04 20 In current work, new hybrid composite have been prepared by mixing gold nanocolloid physically with PVA-Fe₂O₃. Morphological, compositional,  structure and optical properties of hybrid composites were studied by transmission electron microscope (TEM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD)  and UV-visible spectroscopy (UV-VIS). XRD results showed that both Au and Fe2O3 have peaks in the structure and that confirmed by EDS and FTIR results. Microscopes results indicated the nanosized nature of prepared materials. UV–vis spectrum show absorption edge at 440 nm which relates to PVA-Fe2O3 mixed with Au which means there is a red shift after incorporation of Au in the composites. And the energy gap of composite became equal to 2.48 eV after adding Au solution. In current work, new hybrid composite have been prepared by mixing gold nanocolloid physically with PVA-Fe₂O₃. Morphological, compositional,  structure and optical properties of hybrid composites were studied by transmission electron microscope (TEM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD)  and UV-visible spectroscopy (UV-VIS). XRD results showed that both Au and Fe2O3 have peaks in the structure and that confirmed by EDS and FTIR results. Microscopes results indicated the nanosized nature of prepared materials. UV–vis spectrum show absorption edge at 440 nm which relates to PVA-Fe2O3 mixed with Au which means there is a red shift after incorporation of Au in the composites. And the energy gap of composite became equal to 2.48 eV after adding Au solution. https://ijpr.iut.ac.ir/article_3425_07211688a0869d995947a8fb11b215d6.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Relativistic effects in the study of structure and electronic properties of UO2 within DFT+U method Relativistic effects in the study of structure and electronic properties of UO2 within DFT+U method 141 146 3431 10.47176/ijpr.23.3.11777 FA Mahmoud Payami Shabestar School of Physics and Accelerators, Nuclear Science and Technology Research Institute, AEOI, P.O. Box 14395-836, Tehran, Iran 0000-0001-9670-8457 Samira Sheykhi School of Physics and Accelerators, Nuclear Science and Technology Research Institute, AEOI, P.O. Box 14395-836, Tehran, Iran Journal Article 2023 11 01 Electrons of orbitals near to nuclei of heavy atoms acquire speeds comparable to the speed of light in vacuum. Therefore, to study the properties of crystals containing heavy atoms, it is necessary to take into account the relativistic effects. In this work, using the first-principles DFT+U method, we have calculated the electronic structure and geometric properties of uranium dioxide UO₂ within full-relativistic, scalar-relativistic, and non-relativistic formulations, and compared the results. It is shown that: (i) the non-relativistic scheme gives results very far form experimental values for both lattice constant and bang gap; (ii) in full-relativistic case which the spin-orbit effects are included, the Kohn-Sham band-gap is increased by 6.2% and the lattice constant decreases by 0.05% compared to scalar-relativistic one. Therefore, in the study of geometric properties of UO_2, using the scalar-relativistic regime is quite accurate and one does not need to perform much more expensive full-relativistic calculations whenever one does not study the electronic excitation properties. Electrons of orbitals near to nuclei of heavy atoms acquire speeds comparable to the speed of light in vacuum. Therefore, to study the properties of crystals containing heavy atoms, it is necessary to take into account the relativistic effects. In this work, using the first-principles DFT+U method, we have calculated the electronic structure and geometric properties of uranium dioxide UO₂ within full-relativistic, scalar-relativistic, and non-relativistic formulations, and compared the results. It is shown that: (i) the non-relativistic scheme gives results very far form experimental values for both lattice constant and bang gap; (ii) in full-relativistic case which the spin-orbit effects are included, the Kohn-Sham band-gap is increased by 6.2% and the lattice constant decreases by 0.05% compared to scalar-relativistic one. Therefore, in the study of geometric properties of UO_2, using the scalar-relativistic regime is quite accurate and one does not need to perform much more expensive full-relativistic calculations whenever one does not study the electronic excitation properties. https://ijpr.iut.ac.ir/article_3431_84c2d4860a0fc27bcf854c444fb8b400.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 The role of the temperature anisotropy in the deuterium-tritium fuel ignition under the effect of relativistic shock waves The role of the temperature anisotropy in the deuterium-tritium fuel ignition under the effect of relativistic shock waves 147 156 3428 10.47176/ijpr.23.3.81746 FA Fatemeh Khodadadi Azadboni Department of Physics Education, Farhangian University, P.O. Box 14665-889, Tehran, Iran 0000-0003-0896-7358 Elham Khademloo Department of Nuclear Physics, Faculty of Basic Sciences, University of Mazandaran, P.O. Box 47415-416, Babolsar, Iran Mohammad Mahdavi Department of Nuclear Physics, Faculty of Basic Sciences, University of Mazandaran, P.O. Box 47415-416, Babolsar, Iran Journal Article 2023 08 31 This paper investigates the influence of temperature anisotropy on the ignition criterion of deuterium-tritium fuel in fast ignition fusion schemes that rely on short-pulse lasers-generated shock waves. The results show that increasing the temperature anisotropy parameter, β = T_⊥/T_∥, unexpectedly increases the fraction of alpha particles created and deposited into the ignition domain. For β < 1, the maximum confinement parameter remains below 4 g/cm², whereas for β > 1, it exceeds 4 g/cm². The fusion energy fraction, f_α, decreases throughout the laser pulse irradiation of the fuel (1 picosecond). A 100-fold increase in the temperature anisotropy parameter, β, leads to a 38% increase in the required plasma density times the hot spot dimension for fuel ignition. However, for β less than 1, the fusion energy fraction deposited decreases with time and reaches its minimum value of about 0.1 at the end of the laser pulse. This paper investigates the influence of temperature anisotropy on the ignition criterion of deuterium-tritium fuel in fast ignition fusion schemes that rely on short-pulse lasers-generated shock waves. The results show that increasing the temperature anisotropy parameter, β = T_⊥/T_∥, unexpectedly increases the fraction of alpha particles created and deposited into the ignition domain. For β < 1, the maximum confinement parameter remains below 4 g/cm², whereas for β > 1, it exceeds 4 g/cm². The fusion energy fraction, f_α, decreases throughout the laser pulse irradiation of the fuel (1 picosecond). A 100-fold increase in the temperature anisotropy parameter, β, leads to a 38% increase in the required plasma density times the hot spot dimension for fuel ignition. However, for β less than 1, the fusion energy fraction deposited decreases with time and reaches its minimum value of about 0.1 at the end of the laser pulse. https://ijpr.iut.ac.ir/article_3428_4500e4037738e13c0c18db508e18d483.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Electromagnetic medium analogous to Rindler space-time and Poincaré space Electromagnetic medium analogous to Rindler space-time and Poincaré space 157 161 3457 10.47176/ijpr.23.3.01769 FA Zahra Hassani Department of Fundamental Physics, Faculty of Physics, Alzahra University, Tehran, Iran Ahmad Shariati Department of Fundamental Physics, Faculty of Physics, Alzahra University, Tehran, Iran 0000-0002-8090-9905 Mohammad Khorrami Department of Fundamental Physics, Faculty of Physics, Alzahra University, Tehran, Iran Journal Article 2023 10 23 By specifying the electric susceptibility tensor and the magnetic permeability tensor , we introduce two isotropic but inhomogeneous media which are analogous to the Rindler space-time and the Poincaré ‎half-space‎. The propagation of electromagnetic waves in these media is investigated By specifying the electric susceptibility tensor and the magnetic permeability tensor , we introduce two isotropic but inhomogeneous media which are analogous to the Rindler space-time and the Poincaré ‎half-space‎. The propagation of electromagnetic waves in these media is investigated https://ijpr.iut.ac.ir/article_3457_e1fc9c082df6cfff8cbcfff2b5a722ef.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Synthesis of high transparency of F doped NiO monocrystalline thin films by spray deposition Synthesis of high transparency of F doped NiO monocrystalline thin films by spray deposition 163 168 3436 10.47176/ijpr.23.3.11780 FA Said Benramache Laboratoire des Matériaux, des Énergies et de l’Environnement, University of Biskra 07000, Algeria Mounira MAMMI Department of Physics, University of El-Oued, 39000, Algeria Yacine AOUN Mechanical Department, Faculty of Technology, University of El-Oued, El-Oued 39000, Algeria Amira SBAIHI Laboratoire des Matériaux, des Énergies et de l’Environnement, University of Biskra 07000, Algeria Journal Article 2023 11 04 The main objective of this work is to investigate a new material based on fluorine doped NiO thin films by spray deposition technique. Nickel nitrate hexahydrate Ni(NO₃)₂.6H₂O and ammonium fluoride (NHF4) with a ratio of F/Ni = 0.04 were used to prepare F doped NiO. The structural, optical and electrical properties of F doped NiO thin films were investigated with different NiO:F solution volumes of 5, 10, 15 and 20 ml using the spray technique. The prepared F doped NiO thin films have a monocrystalline nature with a cubic structure; the (111) diffraction peak is the preferred orientation; the maximum crystallite size is 19.21 nm obtained for 20 ml. The optical property shows that the all the prepared F doped NiO thin films have a good transmittance of about 80 % in the visible region. The F doped NiO thin films deposited with 20 ml have a minimum optical gap energy of 3.51 eV and the highest value of Urbach energy of 0,689 meV. However, the thin film prepared with 5 ml has a minimum electrical resistivity of 231 Ω.cm, which can be used as a gas sensing. The main objective of this work is to investigate a new material based on fluorine doped NiO thin films by spray deposition technique. Nickel nitrate hexahydrate Ni(NO₃)₂.6H₂O and ammonium fluoride (NHF4) with a ratio of F/Ni = 0.04 were used to prepare F doped NiO. The structural, optical and electrical properties of F doped NiO thin films were investigated with different NiO:F solution volumes of 5, 10, 15 and 20 ml using the spray technique. The prepared F doped NiO thin films have a monocrystalline nature with a cubic structure; the (111) diffraction peak is the preferred orientation; the maximum crystallite size is 19.21 nm obtained for 20 ml. The optical property shows that the all the prepared F doped NiO thin films have a good transmittance of about 80 % in the visible region. The F doped NiO thin films deposited with 20 ml have a minimum optical gap energy of 3.51 eV and the highest value of Urbach energy of 0,689 meV. However, the thin film prepared with 5 ml has a minimum electrical resistivity of 231 Ω.cm, which can be used as a gas sensing. https://ijpr.iut.ac.ir/article_3436_61f2585b0ebcf1f532c4d1ec9a7d51aa.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 The impact of random memory resetting on a non-Markovian random walk The impact of random memory resetting on a non-Markovian random walk 169 175 3459 10.47176/ijpr.23.3.21799 FA Hamid Vazini Hekmat Department of Physics, Faculty of Science, Bu-Ali Sina University, Hamedan, Iran Farhad Jafarpour Hamadani Department of Physics, Faculty of Science, Bu-Ali Sina University, Hamedan, Iran 0000-0003-0477-9990 Journal Article 2023 12 09 In this study, we present a discrete-time non-Markov process, referred to as an Elephant Random Walk, implemented on an infinite one-dimensional lattice, with the inclusion of random memory resetting. Upon each random resetting event, the walker completely loses its memory. Through analytical calculations, we determine the moments of displacement in the presence of random resetting. Our findings demonstrate that the process does not attain a steady state. However, the long-time behavior of the moments reveals that, under specific conditions, the displacement distribution follows a Gaussian distribution. By manipulating the resetting mechanism, the transition from diffusive to superdiffusive behavior, or vice versa, can be induced in the process. In this study, we present a discrete-time non-Markov process, referred to as an Elephant Random Walk, implemented on an infinite one-dimensional lattice, with the inclusion of random memory resetting. Upon each random resetting event, the walker completely loses its memory. Through analytical calculations, we determine the moments of displacement in the presence of random resetting. Our findings demonstrate that the process does not attain a steady state. However, the long-time behavior of the moments reveals that, under specific conditions, the displacement distribution follows a Gaussian distribution. By manipulating the resetting mechanism, the transition from diffusive to superdiffusive behavior, or vice versa, can be induced in the process. https://ijpr.iut.ac.ir/article_3459_13d63838ef1fb6f34ca2dc6821c60e49.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Integrated plasma control system for IR-T1 tokamak with disruption mitigation Integrated plasma control system for IR-T1 tokamak with disruption mitigation 177 187 3473 10.47176/ijpr.23.3.21798 FA Ahmad Naghidokht School of Physics, Damghan University, Damghan, Semnan 0000-0001-8705-4885 Morteza Janfaza School of Physics, Damghan University Mahmood Ghorannevis Plasma Physics Research Center, Islamic Azad University, Science and Research Branch, Tehran, Iran Journal Article 2023 12 07 Controlling tokamak plasmas is a complex process that is affected by structured uncertainties and unmodeled dynamics. To overcome these challenges and achieve a well-defined robust behavioral outcome, it is crucial to develop standard controllers. The decoupling control theory for Multiple-Input Multiple-Output (MIMO) processes is a powerful technique that allows the mitigation or elimination of undesirable cross-coupling terms in tokamaks, making it superior to the Single-Input Single-Output (SISO) control scheme. Our study proposes two types of controllers, PID-tuned and cascaded-robust controllers, that exploit decoupling and robustness for horizontal position and current control of plasma in IR-T1 tokamak. We compare the controllers through simulations and study the impact of changing the vertical field coil voltage on the cross-coupling of these two plasma parameters. The results demonstrate that the PID-tuned controller outperforms the robust controller in terms of meeting control requirements, disturbance rejection, reference value tracking, and disruption mitigation, especially in cross-coupling controls. Of course, the definitive confirmation requires experimental studies with more diverse conditions and, finally construction and operation of these controllers in tokamaks. Controlling tokamak plasmas is a complex process that is affected by structured uncertainties and unmodeled dynamics. To overcome these challenges and achieve a well-defined robust behavioral outcome, it is crucial to develop standard controllers. The decoupling control theory for Multiple-Input Multiple-Output (MIMO) processes is a powerful technique that allows the mitigation or elimination of undesirable cross-coupling terms in tokamaks, making it superior to the Single-Input Single-Output (SISO) control scheme. Our study proposes two types of controllers, PID-tuned and cascaded-robust controllers, that exploit decoupling and robustness for horizontal position and current control of plasma in IR-T1 tokamak. We compare the controllers through simulations and study the impact of changing the vertical field coil voltage on the cross-coupling of these two plasma parameters. The results demonstrate that the PID-tuned controller outperforms the robust controller in terms of meeting control requirements, disturbance rejection, reference value tracking, and disruption mitigation, especially in cross-coupling controls. Of course, the definitive confirmation requires experimental studies with more diverse conditions and, finally construction and operation of these controllers in tokamaks. https://ijpr.iut.ac.ir/article_3473_99be9f83741d1275639df2c1e4d0072f.pdf

The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Comparison of SMC and OMC results in determining the ground-state and meta-stable states solutions for UO2 in the DFT+U method Comparison of SMC and OMC results in determining the ground-state and meta-stable states solutions for UO2 in the DFT+U method 189 195 3474 10.47176/ijpr.23.3.11820 FA Mahmoud Payami School of Physics & Accelerators, Nuclear Science and Technology Research Institute, AEOI, P. O. Box 14395-836, Tehran, Iran 0000-0001-9670-8457 Journal Article 2024 01 12 Correct prediction of the behavior of UO2 crystal, which is an anti-ferromagnetic system with strongly correlated electrons, is possible by using a modified density functional theory, the DFT+U method. In the context of DFT+U, the energy of the crystal turns out to be a function with several local minima, the so-called meta-stable states, and the lowest energy state amongst them is identified as the ground state. OMC was a method that was used in DFT+U to determine the ground state. The SMC method, by leveraging only the oxygen electronic spin-polarization degrees of freedom, has indeed uncovered the multi-minima energy structure within  the DFT+U approach and produced results consistent  with the experimental data. In this work, we compare the SMC and OMC results and show that although the ground states of the two methods have similar energies and geometries, the electronic structures have significant differences. Moreover, we show that the GS obtained from SMC is by 0.0022 Ry/(formula unit) above that of OMC. The discrepancy in  GS results between the two methods suggests that they explore minimum-energy states across different electron densities subspaces. Neither method alone is sufficient to identify the global minimum energy state. Therefore, to obtain the global-minimum state of energy one has to search over larger subspaces that involve both occupation matrices of U atoms and starting magnetization of O atoms. Correct prediction of the behavior of UO2 crystal, which is an anti-ferromagnetic system with strongly correlated electrons, is possible by using a modified density functional theory, the DFT+U method. In the context of DFT+U, the energy of the crystal turns out to be a function with several local minima, the so-called meta-stable states, and the lowest energy state amongst them is identified as the ground state. OMC was a method that was used in DFT+U to determine the ground state. The SMC method, by leveraging only the oxygen electronic spin-polarization degrees of freedom, has indeed uncovered the multi-minima energy structure within  the DFT+U approach and produced results consistent  with the experimental data. In this work, we compare the SMC and OMC results and show that although the ground states of the two methods have similar energies and geometries, the electronic structures have significant differences. Moreover, we show that the GS obtained from SMC is by 0.0022 Ry/(formula unit) above that of OMC. The discrepancy in  GS results between the two methods suggests that they explore minimum-energy states across different electron densities subspaces. Neither method alone is sufficient to identify the global minimum energy state. Therefore, to obtain the global-minimum state of energy one has to search over larger subspaces that involve both occupation matrices of U atoms and starting magnetization of O atoms. https://ijpr.iut.ac.ir/article_3474_e91068fff3d7fa1594dfdf3b4308433a.pdf