Isfahan University of Technology, The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 3 3 2019 11 26 Calculation of electronic structure and density of state for BaTiO3 Calculation of electronic structure and density of state for BaTiO<sub>3</sub> 169 175 681 FA H. Salehi S. M. Hosseini N. Shahtahmasebi Journal Article 2019 11 26   The electronic structure, density of state (DOS) and electronic density of state inparaelectric cubic crystal Ba TiO3 are studied using full potential-linearized augmented plane wave (FP-LAPW) method in the framework of the density functional theory (DFT) with the generalized gradient approximation (GGA) by the WIEN2K package. The results show a direct band gap of 1.8 eV at the point in the Brillouin zone. The calculated band structure and density of state of BaTiO3 are in good agreement with theoretical and experimental results.   The electronic structure, density of state (DOS) and electronic density of state inparaelectric cubic crystal Ba TiO3 are studied using full potential-linearized augmented plane wave (FP-LAPW) method in the framework of the density functional theory (DFT) with the generalized gradient approximation (GGA) by the WIEN2K package. The results show a direct band gap of 1.8 eV at the point in the Brillouin zone. The calculated band structure and density of state of BaTiO3 are in good agreement with theoretical and experimental results. electronic structure BaTiO3 FP-LAPW density of state GGA DFT https://ijpr.iut.ac.ir/article_681_e9f53eec469c580a52c5f3fdf40d8421.pdf
Isfahan University of Technology, The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 3 3 2019 11 26 Cosmological solutions of Brans-Dicke equations with cosmological constant Cosmological solutions of Brans-Dicke equations with cosmological constant 177 183 682 FA I. Ahmadi-Azar Journal Article 2019 11 26   In this paper, the analytical solutions of Brans-Dicke (B-D) equations with cosmological constant are presented, in which the equation of state of the universe is P=mÙ° ρ , under the assumption φRn=c between the B-D field and the scale factor of the universe. The flat (K=0) Robertson- Walker metric has been considered for the metric of the universe. These solutions are rich in the sense that they include dust B-D theory with cosmological constant, Nariai Ù=° solutions, vacuum solutions of Ohanlen-Tupper and inflationary  Ù=° solutions.   In this paper, the analytical solutions of Brans-Dicke (B-D) equations with cosmological constant are presented, in which the equation of state of the universe is P=mÙ° ρ , under the assumption φRn=c between the B-D field and the scale factor of the universe. The flat (K=0) Robertson- Walker metric has been considered for the metric of the universe. These solutions are rich in the sense that they include dust B-D theory with cosmological constant, Nariai Ù=° solutions, vacuum solutions of Ohanlen-Tupper and inflationary  Ù=° solutions. cosmological constant Brans-Dicke-theory inflation https://ijpr.iut.ac.ir/article_682_8350c83f8bcbcdc56ba22a53e597f5c5.pdf
Isfahan University of Technology, The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 3 3 2019 11 26 parameterrization of microphysical and dynamical processes of rainfall in thunderstorm cloud model parameterrization of microphysical and dynamical processes of rainfall in thunderstorm cloud model 185 198 683 FA S. J. J. B. Journal Article 2019 11 26   In this research parameterization of the precipitation process in Ogura &amp Takahashi (O-T) thunderstorm model was improved in microphysical processes, specially in the autoconversion process to form raindrops, in the glaciation process and in the terminal velocities of rain and hail. The rainfall intensity became much heavier with Kesslers parameterization, the second peak of the rainfall intensity disappeared with Biggs freezing probability, and the rainfall intensity became much heavier and sharper with Lin et als terminal velocities of rain and hail than in the O-T original model. Finally, the derived rainfall pattern based on the improved model has much similarities to the observation data. This paper expresses the basic research for studying the physical treatment in clouds. The modified O-T model has different applications in analyzing radar observation data, estimate the potential of soil erosion, parameteriztion of shower in mesoscale numerical weather prediction and eta.   In this research parameterization of the precipitation process in Ogura &amp Takahashi (O-T) thunderstorm model was improved in microphysical processes, specially in the autoconversion process to form raindrops, in the glaciation process and in the terminal velocities of rain and hail. The rainfall intensity became much heavier with Kesslers parameterization, the second peak of the rainfall intensity disappeared with Biggs freezing probability, and the rainfall intensity became much heavier and sharper with Lin et als terminal velocities of rain and hail than in the O-T original model. Finally, the derived rainfall pattern based on the improved model has much similarities to the observation data. This paper expresses the basic research for studying the physical treatment in clouds. The modified O-T model has different applications in analyzing radar observation data, estimate the potential of soil erosion, parameteriztion of shower in mesoscale numerical weather prediction and eta. thunderstorm cloud,numerical modeling, ogura&amp Takahashi, microphysical and dynamical processes, Kessler parameterization, rainfall intensity https://ijpr.iut.ac.ir/article_683_cbcafbb64d6f7e2f4a8ddbc5e127d4e2.pdf
Isfahan University of Technology, The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 3 3 2019 11 26 Statistical Characteristics of magnetic recording particles Statistical Characteristics of magnetic recording particles 199 212 684 FA S. A. S. M. A. Journal Article 2019 11 26   In magnetic recording media, the remanent magnetization loop, Mr(H)has some parameters, which explain the prperties of the medium in view of the storage density and signal-to-noise ratio. It is necessary to find the mechanism of Mr variations from the statistical characteristics of the system. We have prepared samples of single-domain ascicolar iron particles with 0.3 length, and the oriented textures of particles formed. The easy axis distribution of particles in the samples was determind using the results of magnetic measurements. The effect of the distribution width on Mr and corecivity (Hc) have been studied. The deviation of results from the Stoner-Wohlforth model for Hc indicates a correlation in the medium due to the dipole-dipole interaction. We also present a technique for determining the switching field distribution in medium, which has been used for various samples. A narrow distribution leads to narrow transition regions in the recording media, and an increase of signal. A high switching field at the maximum of distribution indicates the ability of high recording density.   In magnetic recording media, the remanent magnetization loop, Mr(H)has some parameters, which explain the prperties of the medium in view of the storage density and signal-to-noise ratio. It is necessary to find the mechanism of Mr variations from the statistical characteristics of the system. We have prepared samples of single-domain ascicolar iron particles with 0.3 length, and the oriented textures of particles formed. The easy axis distribution of particles in the samples was determind using the results of magnetic measurements. The effect of the distribution width on Mr and corecivity (Hc) have been studied. The deviation of results from the Stoner-Wohlforth model for Hc indicates a correlation in the medium due to the dipole-dipole interaction. We also present a technique for determining the switching field distribution in medium, which has been used for various samples. A narrow distribution leads to narrow transition regions in the recording media, and an increase of signal. A high switching field at the maximum of distribution indicates the ability of high recording density. magnetic fine particles switching field distribution easy axis distribution magnetic recording media https://ijpr.iut.ac.ir/article_684_877831d02a6ff87272f14938d9115ffb.pdf
Isfahan University of Technology, The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 3 3 2019 11 26 Sea surface temperature and Ekman transport in the Persian Gulf Sea surface temperature and Ekman transport in the Persian Gulf 213 222 685 FA E. H. H. N. Journal Article 2019 11 26   The wind drift motion of the water which is produced by the stress of the wind exerted upon the surface of the ocean is described by Ekmans theory (1905). Using the mean monthly values for the wind stress and SST, seasonal Ekman transport for the Persian Gulf was computed and contoured. The geostrophic winds have combined with the SST to estimate the effect of cooling due to Ekman transport of colder northern waters and inflow from the Oman Sea. The monthly SST mainly obtained from the 10 10 grided data of Levitus atlas and Hormuz Cruis Experiment for 1997.   Analyses show a NW to SE Ekman transport due to wind stress and significant interannual variability of SST on sea surface in the Persian Gulf. The seasonal variation of SST shows a continental pattern due to severe interaction between the land and sea. But these variations somehow moderates because of Ekman transport in Persian Gulf.   The wind drift motion of the water which is produced by the stress of the wind exerted upon the surface of the ocean is described by Ekmans theory (1905). Using the mean monthly values for the wind stress and SST, seasonal Ekman transport for the Persian Gulf was computed and contoured. The geostrophic winds have combined with the SST to estimate the effect of cooling due to Ekman transport of colder northern waters and inflow from the Oman Sea. The monthly SST mainly obtained from the 10 10 grided data of Levitus atlas and Hormuz Cruis Experiment for 1997.   Analyses show a NW to SE Ekman transport due to wind stress and significant interannual variability of SST on sea surface in the Persian Gulf. The seasonal variation of SST shows a continental pattern due to severe interaction between the land and sea. But these variations somehow moderates because of Ekman transport in Persian Gulf. sea surface temperature salinity thermohaline Ekman transport Persian Gulf https://ijpr.iut.ac.ir/article_685_4c288c10695e7872cf0b122b0b6e92bb.pdf
Isfahan University of Technology, The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 3 3 2019 11 26 Study of electronic and Structural Properties of CaS Study of electronic and Structural Properties of CaS 223 232 686 FA M. Mirfenderski H. Akbarzadeh A. Mokhtari Journal Article 2019 11 26   The electronic and structural properties of CaS are calculated using full potential linearized augmented plane wave (FP-LAPW) method within the local density approximation (LDA) and generalized gradient approximation (GGA) for the exchange-correlation energy. For both structures, NaCl structure (B1) and CsCl structure (B2), the obtained values for lattice parameters, Bulk modulus and its pressure derivative and transition pressure are in reasonable agreement with the experimental values. For electronic properties, the obtained value for band gap is smaller than the experimental value as well as other calculated results based on density functional theory. Engel and Vosko calculated an exchange potential for some atoms within the so-called optimize-potential model and then used the virial relation and constructed a new exchange-correlation functional (EV-GGA). We used that functional and obtained reasonable results for band gap. Finally we investigated the possibility for a third phase (Zinc Blend structure) for this crystal.   The electronic and structural properties of CaS are calculated using full potential linearized augmented plane wave (FP-LAPW) method within the local density approximation (LDA) and generalized gradient approximation (GGA) for the exchange-correlation energy. For both structures, NaCl structure (B1) and CsCl structure (B2), the obtained values for lattice parameters, Bulk modulus and its pressure derivative and transition pressure are in reasonable agreement with the experimental values. For electronic properties, the obtained value for band gap is smaller than the experimental value as well as other calculated results based on density functional theory. Engel and Vosko calculated an exchange potential for some atoms within the so-called optimize-potential model and then used the virial relation and constructed a new exchange-correlation functional (EV-GGA). We used that functional and obtained reasonable results for band gap. Finally we investigated the possibility for a third phase (Zinc Blend structure) for this crystal. density funcational theory FP-LAW CaS https://ijpr.iut.ac.ir/article_686_2382d7bac89df7d0faa0061b52d55f6d.pdf
Isfahan University of Technology, The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 3 3 2019 11 26 Calculation of charge transfer differential cross section by Faddeev approach Calculation of charge transfer differential cross section by Faddeev approach 233 245 687 FA E. G. H. M. B. Journal Article 2019 11 26   A second-order approximation to the Faddeev-Watson-Lovelace treatment of the rearrangement channel is used in a three-body scattering cross sections. In this formalism, the Three-body wave function is expressed by three coupled integral equations, the Faddeev equations, which contian the two-body (off-shell) transition amplitudes, and proved the uniqueness of their solutions. This amplitude corresponds to the summing of infinite numbers of terms involving the electron-projectile and electron-target nuclear potentials in a Born expansion of the transition operator. It thus represents a considerable improvement over a treatment involving only the second-order Born approximation.   Application of this method is tedious because of a difficulty arising from the complicated nature of the two-body off-shell Coulomb T-matrix, which is the basic dynamical ingredient in the formalism. The difficulty arises from the fact that the Coulomb T-matrix does not have a well-defined on-shell limit.   Expressions are derived for projectile scattering angles in the extreme forward directions and for angles centered about the local maximum of the differential cross section [at (mc/Mp < /sub>) Sin600, where mc is the electron mass and Mp < /sub> is the projectile mass] known as the Thomas peak. A mixture of analytical and numerical methods have been used to calculate the transition amplitudes for state to state [H+ +H(nIm)→H (n´I´m´) + H+] reaction and therefore the corresponding cross sections.   Many numerical and analytical calculations are available within a near-the-shell limit for 1s-1s transition of electron-capture process in proton hydrogen collision, but no calculation was performed for the state (nlm) to state (n’l’m’). We have compared the calculated differential cross sections for electron capture of different states and also with the available measured cross sections in the literature.   A second-order approximation to the Faddeev-Watson-Lovelace treatment of the rearrangement channel is used in a three-body scattering cross sections. In this formalism, the Three-body wave function is expressed by three coupled integral equations, the Faddeev equations, which contian the two-body (off-shell) transition amplitudes, and proved the uniqueness of their solutions. This amplitude corresponds to the summing of infinite numbers of terms involving the electron-projectile and electron-target nuclear potentials in a Born expansion of the transition operator. It thus represents a considerable improvement over a treatment involving only the second-order Born approximation.   Application of this method is tedious because of a difficulty arising from the complicated nature of the two-body off-shell Coulomb T-matrix, which is the basic dynamical ingredient in the formalism. The difficulty arises from the fact that the Coulomb T-matrix does not have a well-defined on-shell limit.   Expressions are derived for projectile scattering angles in the extreme forward directions and for angles centered about the local maximum of the differential cross section [at (mc/Mp < /sub>) Sin600, where mc is the electron mass and Mp < /sub> is the projectile mass] known as the Thomas peak. A mixture of analytical and numerical methods have been used to calculate the transition amplitudes for state to state [H+ +H(nIm)→H (n´I´m´) + H+] reaction and therefore the corresponding cross sections.   Many numerical and analytical calculations are available within a near-the-shell limit for 1s-1s transition of electron-capture process in proton hydrogen collision, but no calculation was performed for the state (nlm) to state (n’l’m’). We have compared the calculated differential cross sections for electron capture of different states and also with the available measured cross sections in the literature. electron Capture charge transfer differential cross Section Faddeev formalism transition matrix scattering amplitude https://ijpr.iut.ac.ir/article_687_5721c38e3201e7b435b0b8ec9f0711ae.pdf
Isfahan University of Technology, The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 3 3 2019 11 26 The effects of impurities on the band gap energy of CdS photoconductors The effects of impurities on the band gap energy of CdS photoconductors 247 253 688 FA R. S. A. N. Journal Article 2019 11 26   The basic requirements of the CdS thin films on their applications are high optical transparency, low electrical resistivity, and better crystalinity (e.g.high orientation). Firstly, we prepared CdS films by thermal eveporation techniques on glass substrate and then studied their photoconductivity from room temperature to 200 . Secondly, we prepared CdS films with impurities of Cu, Ag, Au and Al. In doped films with Cu, Ag and Au, we found CdS peak shifts towards lower energies. Our aim was to uas a new and initiative method for temerature and impurities effects on CdS photoconductors.   The basic requirements of the CdS thin films on their applications are high optical transparency, low electrical resistivity, and better crystalinity (e.g.high orientation). Firstly, we prepared CdS films by thermal eveporation techniques on glass substrate and then studied their photoconductivity from room temperature to 200 . Secondly, we prepared CdS films with impurities of Cu, Ag, Au and Al. In doped films with Cu, Ag and Au, we found CdS peak shifts towards lower energies. Our aim was to uas a new and initiative method for temerature and impurities effects on CdS photoconductors. gap energy cadmium sulfide impurities photoconductivity https://ijpr.iut.ac.ir/article_688_1c9206360171caa15bb02d8784b90e4e.pdf
Isfahan University of Technology, The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 3 3 2019 11 26 Symmetry breaking in mirror nuclei55 Co and 55Ni Symmetry breaking in mirror nuclei<sup>55</sup> Co and <sup>55</sup>Ni 253 253 689 FA S. Mohammadi Journal Article 2019 11 26   Yrast states in mirror nuclei 55Co and 55Ni have been populated with a radioactive ion beam using the Isotope Separator On-Line method. A shielded array of 7 Compton suppressed germanium detectors recorded reaction gamma-rays. For channel selection, an array of 128 independent silicon detectors was used to differentiate exit channels with different number of proton and alpha particles emitted. From gamma-gamma and gamma-particle coincidences, three lines in 55Co and one line in 55Ni was obtained for the first time   Yrast states in mirror nuclei 55Co and 55Ni have been populated with a radioactive ion beam using the Isotope Separator On-Line method. A shielded array of 7 Compton suppressed germanium detectors recorded reaction gamma-rays. For channel selection, an array of 128 independent silicon detectors was used to differentiate exit channels with different number of proton and alpha particles emitted. From gamma-gamma and gamma-particle coincidences, three lines in 55Co and one line in 55Ni was obtained for the first time Mirror nuclei Radioactive Ion Beam Coulomb Displacement Energies Decay Schemes Compound Nucleus Fusion-Evaporation https://ijpr.iut.ac.ir/article_689_6b4557ebc32072f438788b72e9883f8d.pdf