Calculation of thermodynamic corrections from electronic exchange effects in ThomasâFermi model employed for hot dense plasma
H
Hosseinkhani
پژوهشکده پلاسما و گداخت هستهای، پژوهشگاه علوم و فنون هستهای، تهران
author
A H
Esmailian Araghi
گروه فیزیک، دانشگاه آزاد اسلامی، واحد قم
author
text
article
2019
per
In this paper, considering the plasma electronic exchange intraction effects, first, Thomas–Fermi equation has been solved numerically. Then, employing the results of these equations, the amount of exchange corrections for pressure and internal energy of the plasma (electron gas with specific atomic number) has been calculated based on variation of plasma density and temperature. The results of the calculations can be used in both quantitative and qualitative description of changing the phase of matter in high temperature and density, encountered with in theoretical and experimental studies of inertial fusion and astro physical phenomena as well.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
127
132
http://ijpr.iut.ac.ir/article_1185_6d66dcb81186f11cd6b91bca22cc8ade.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.127
Design of surface plasmon resonance biosensor with one dimensional photonic crystal for detection of cancer
M
Sharifi
دانشکده علوم و فناوریهای نوین، دانشگاه تحصیلات تکمیلی صنعتی و فناوری پیشرفته کرمان، کرمان
author
H
Pashaei Adl
دانشکده فیزیک، دانشگاه تبریز، تبریز
author
H
Tajalli
دانشکده فیزیک، دانشگاه تبریز، تبریز قطب علمی فوتونیک، پژوهشکده فیزیک کاربردی و ستاره شناسی، دانشگاه تبریز، تبریز
author
A
Bahrampour
دانشکده فیزیک، دانشگاه صنعتی شریف، تهران
author
text
article
2019
per
In recent years, development of highly sensitive biosensors is the main purpose of researchers to diagnose and prevent diseases. Accordingly, in this paper, surface plasmon resonance (SPR) biosensor has been designed based on one dimensional layered structures. With regard to the fact that the quality of SPR sensors strongly depends on the reflectance amplitude and full width at half maximum (FWHM) of the SPR curves, a novel structure, , is presented using transfer matrix method (TMM), to satisfy these two condition. Besides, the sensitivity of this biosensor has been calculated and it has been employed to diagnose leukemia for Jurkat cells.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
133
138
http://ijpr.iut.ac.ir/article_1186_d5afbb17a6c1dda5a639cc18e19d8d21.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.133
Algebraic dynamics of Bloch oscillations of ultra - cold atoms in optical lattice
H
Pahlavani
گروه فیزیک، دانشگاه قم، قم
author
A
Zamani
گروه فیزیک، دانشگاه قم، قم
author
text
article
2019
per
The dynamic of a charged quantum particle in a system of arrays of quantum well in tight-binding model, under the effect an external field, in one and two dimension, is studied by algebraic approach. The persistent (quantum confinement) and transmission (quantum teleportaion) probabilities of this quantum particle in terms of infinite-variable Bessel functions is calculated and the results is discussed by numerical method.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
139
145
http://ijpr.iut.ac.ir/article_1187_66efc28b766d52147e8de3170cddd45d.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.139
On the effect of moisture content on drying rate in porous media
R
Torabi
دانشکده فیزیک، دانشگاه تفرش، تفرش
author
S
Vasheghani Farahani
دانشکده فیزیک، دانشگاه تفرش، تفرش
author
G R
Jafari
دانشکده فیزیک، دانشگاه شهید بهشتی، تهران
author
text
article
2019
per
In this study, drying process is modeled in porous media using random walk theory. In this line, first the effect of microscopic quantities derived from random walk theory has been studied on drying rate. Then, the relationship between drying rate and moisture content is obtained taking convection into account. The results obtained in this study indicates the effect of convection on the process of drying in porous media.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
147
152
http://ijpr.iut.ac.ir/article_1188_5b10a0041296681c23a566c56a48c384.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.147
Self-similar expansion of plasma into vacuum including thermal ions
R
Shokoohi
گروه فیزیک، دانشکده علوم پایه، دانشگاه بجنورد، بجنورد
author
L
Yazdani
گروه فیزیک، دانشکده علوم پایه، دانشگاه شهرکرد، شهرکرد
author
text
article
2019
per
Expansion of one dimensional collisionless plasma into vacuum is studied under different initial ions temperature. In this study, a simulation code is used, in which the electrons dynamic is determined by Vlasov equation and the ions dynamic is determined by fluids equations. Finally, the effect of initial ions temperature on the expansion of plasma into vacuum is investigated and the obtained results are compared with self-similar solutions associated with plasma expansion including thermal ions. It is shown that in the area behind the ion front, in which quasi-neutrality conditions exists, the self-similar solutions coincide with the simulation results.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
153
158
http://ijpr.iut.ac.ir/article_1189_696ca6348a4c56d762ab49da2842a40f.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.153
Spin-dependent electrical transport in Fe-MgO-Fe heterostructures
A A
Shokri
گروه فیزیک، دانشکده علوم پایه، دانشگاه پیام نور، تهران
author
S
Khabbaz
گروه فیزیک، دانشکده علوم پایه، دانشگاه پیام نور، تهران
author
text
article
2019
per
In this paper, spin-dependent electrical transport properties are investigated in a single-crystal magnetic tunnel junction (MTJ) which consists of two ferromagnetic Fe electrodes separated by an MgO insulating barrier. These properties contain electric current, spin polarization and tunnel magnetoresistance (TMR). For this purpose, spin-dependent Hamiltonian is described for Δ1 and Δ5 bands in the transport direction. The transmission is calculated by Green's function formalism based on a single-band tight-binding approximation. The transport properties are investigated as a function of the barrier thickness in the limit of coherent tunneling. We have demonstrated that dependence of the TMR on the applied voltage and barrier thickness. Our numerical results may be useful for designing of spintronic devices. The numerical results may be useful in designing of spintronic devices.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
159
164
http://ijpr.iut.ac.ir/article_1190_114b08a4e87b2df1ffe992ba2b66b936.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.159
Thermodynamic properties of and Nuclei using modified Ginzburg-Landau theory
V
Dehghani
گروه فیزیک، دانشکده علوم، دانشگاه سیستان و بلوچستان، زاهدان
author
A A
Mehmandoost-Khajeh-Dad
گروه فیزیک، دانشکده علوم، دانشگاه سیستان و بلوچستان، زاهدان
author
P
Mohammadi
گروه فیزیک، دانشکده علوم، دانشگاه سیستان و بلوچستان، زاهدان
author
text
article
2019
per
In this paper, formulation of Modified Ginsberg – Landau theory of second grade phase transitions has been expressed. Using this theory, termodynamic properties, such as heat capacity, energy, entropy and order parameters ofandnuclei has been investigated. In the heat capacity curve, calculated according to tempreture, a smooth peak is observed which is assumed to be a signature of transition from the paired phase to the normal phase of the nuclei. The same pattern is also observed in the experimental data of the heat capacity of the studied nuclei. Calculations of this model shows that, by increasing tempreture, expectation value of the order parameter tends to zero with smoother slip, comparing with Ginsberg – Landau theory. This indicates that the pairing effect exists between nucleons even at high temperatures. The experimental data obtained confirms the results of the model qualitatively.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
165
172
http://ijpr.iut.ac.ir/article_1191_5520b3f42845527c43ede15086d6cfa0.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.165
Sol-gel growth of TiO2 nanocrystals in n-heptan and their deposition for application in dye sensitized solar cells
Z
Anajafi
گروه فیزیک، دانشکده علوم، دانشگاه اراک، اراک
author
M
Marandi
گروه فیزیک، دانشکده علوم، دانشگاه اراک، اراک
author
text
article
2019
per
In this study, TiO2 nanocrystals were prepared by sol-gel method through the hydrolysis of the titanium tetraisopropoxide in n-heptan solution. The beneficial role of n-heptan solvent was the dilution of the reacting precursors. This could consequently create smaller TiO2 nanocrystals and a better powder effective area. The anatase phase TiO2 nanopowder was achieved by performing an annealing process at 450 ˚C for 1h. Then, the TiO2 nanocrystals were added to an aqueous solution of polyethylene glycol with suitable concentration, as a pastiness factor, to form a viscous TiO2 paste . Finally the prepared paste was deposited on glass FTO substrates by standard doctor blade method and the photoanode of the dye sensitized solar cells was prepared.Then other steps, consisting of dye adsorption, preparation of platinum counter electrode and injection of electrolyte were performed. The results demonstrated that the energy conversion efficiency was maximum for the cell with 15 μm photoanode thickness. The photovoltaic parameters of this cell were measured as 12.44 mA/cm2 , 655 mV, 0.55 and 4.4 % for the Jsc, Voc, FF and efficiency, respectively.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
173
177
http://ijpr.iut.ac.ir/article_1192_d13bfdbbf4cfa36c5ab13cdc0fa185ae.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.173
On the energy gain enhancement of DT+D3He fuel configuration in nuclear fusion reactor driven by heavy ion beams
S
Khoshbinfar
1. گروه فیزیک، دانشکده علوم پایه، دانشگاه گیلان، رشت
author
S A
Taghavi
2. دانشکده فیزیک، دانشگاه دامغان، دامغان
author
text
article
2019
per
It is expected that advanced fuels be employed in the second generation of nuclear fusion reactors. Theoretical calculations show that in such a fuel, a high plasma temperature about 100 keV is a requisite for reaction rate improvement of nuclear fusion. However, creating such a temporal condition requires a more powerful driver than we have today. Here, introducing an optimal fuel configuration consisting of DT and D-3He layers, suitable for inertial fusion reactors and driven by heavy ion beams, the optimal energy gain conditions have been simulated and derived for 1.3 MJ system. It was found that, in this new fuel configuration, the ideal energy gain, is 22 percent more comparing with energy gain in corresponding single DT fuel layer. Moreover, the inner DT fuel layer contributed as an ignition trigger, while the outer D3He fuel acts as particle and radiation shielding as well as fuel layer.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
179
193
http://ijpr.iut.ac.ir/article_1193_cb9f409eaf919866fe8ee8a50206d0ca.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.179
Relativistic Cherenkov radiation in a magneto-dielectric media
مریم
محمدی خشوئی
گروه فیزیک، دانشکده علوم، دانشگاه زنجان، زنجان
author
text
article
2019
per
In this paper, relativistic Cherenkov radiation was studied in a 3-D magneto-dielectric medium. Electric permittivity and magnetic permeability of the medium as functions of frequency, are assumed to satisfy Kramers- Kronig equations. A new interaction Hamiltonian, which is different from Hamiltonian term in non-relativistic state, was introduced by the quantized vector potential field and particle field operator obtained from the second quantization method. The rate of electron energy dissipation was calculated using Fermi’s golden rule.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
195
198
http://ijpr.iut.ac.ir/article_1194_7c0f36ab308e4856df0451bc9ac616be.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.195
Corrections of the spectra with de sitter background in Krein space
M
Mohsenzadeh
1. گروه فیزیک، دانشگاه آزاد اسلامی واحد قم، قم
author
E
Yusofi
2. گروه فیزیک، واحد آیت الله آملی، دانشگاه آزاد اسلامی، آمل
author
text
article
2019
per
Gravitational waves are the last unconfirmed prediction of the general relativity. These waves are tiny fluctuations in world frame that dessipate energy throghout space. The gravitatinal waves spectra of fluctuations can be originated from the non-linear effects during different cosmic evolution periods, especially from initially non-linear and excited vacuum state in the very early universe. Based on this fact, in this paper introducing "excited-de Sitter vacuum" as a fundamental mode, the obtained power spectrum has been investigated. Corrected spectra obtained from Hilbert and Krein spaces are compared.The renormalization approach presented in this work, preserves the curved space-time symmetry and stimulates us to use excited de Sitter mode. Also, the corrections obtained from the non-linear mode includes the second-order corrections and in the linear limit accords with the results from conventional methods.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
199
205
http://ijpr.iut.ac.ir/article_1195_ef32f89341b2a3fb90590f3fdcb469e2.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.199
Thomas-Fermi calculations for determination of critical properties of symmetric nuclear matter on the basis of extended effective mass approach
M
Ghazanfari Mojarrad
دانشکده فیزیک، دانشگاه کاشان، کاشان
author
S K
Mousavi Khoreshtami
دانشکده فیزیک، دانشگاه کاشان، کاشان
author
A
Mostajeran Gurtani
دانشکده فیزیک، دانشگاه کاشان، کاشان
author
text
article
2019
per
Using mean-field and semi-classical approximation of Thomas-Fermi, within a statistical model, equation of state and critical properties of symmetric nuclear matter is studied. In this model, two body and phenomenological interaction of Myers and Swiatecki is used in phase space. By performing a functional variation of the total Helmholtz free energy of system with respect to the nucleonic distribution function in phase space to reach an equilibrium state according to the second low of thermodynamics, we obtain expressions for the effective mass which is only density dependent and the effective one-body potential whereby the key quantity of the extended effective mass with both density and temperature dependency is determined. Accordingly, we reach to the explicit form of distribution function. In this mode, extensive thermodynamic quantities such as, inner energy, entropy and Helmholtz free energy are determined as the functionals of the distribution function for given temperature and density. In this research special attentions has been paid to the critical behavior and stability of symmetric nuclear matter. Our findings about the quantities which describe critical behavior of symmetric nuclear matter are in good agreement with other proposed models.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
207
216
http://ijpr.iut.ac.ir/article_1196_d4cf09b73d2a0d8b8f03646b3d01ef43.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.207
Classification of mini-dimmings associated with extreme ultraviolet eruptions by using graph theory
S
Bazargan
دانشکده فیزیک، دانشگاه زنجان، زنجان
author
H
Safari
دانشکده فیزیک، دانشگاه زنجان، زنجان
author
H
Kaashisaaz
دانشکده فیزیک، دانشگاه زنجان، زنجان
author
text
article
2019
per
Coronal dimmings in both micro and macro scales, can be observed by extreme ultraviolet images, recorded from Solar Dynamics Observatory or Atmospheric Imaging Assembly (SDO/AIA). Mini-dimmings are sometimes associated with wave-like brightening, called coronal mass ejections. Here, the sun full disk images with 171 Å wavelenght, cadence of 2.5, and 0.6 arcsec cell size, were taken on 3 March 2012, then the obtained data were analyzed. Using Zernike Moment and Support Vector Machine (SVM), mini dimmings are detected. 538 active region events, 680 coronal hole events and 723 quiet sun events have been recognized using algorithm. The position, time duration and spatial expansion of these events were computed .The eruptive dimmings have a more spatial development than thermal dimmings after eruptions. This is evident in their graph characteristics length. Then, using graph theory, eruptive and thermal mini-dimmings were classified, with 13% error, for 200 dimmings. 68 dimmings were classified as thermal, and 132 as eruptive. To do this, evolution of graph characteristic length were used.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
217
223
http://ijpr.iut.ac.ir/article_1197_d81f6c477dbce1b521ebbe92934c9ae2.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.217
The effect of bond defect movement on the electronic conductance of linear and cyclic nanostructures
H
Rabani
1. گروه فیزیک، دانشکده علوم پایه، دانشگاه شهرکرد، شهرکرد2. مرکز پژوهشی فناوری نانو، دانشگاه شهرکرد، شهرکرد
author
M
Mardaani
1. گروه فیزیک، دانشکده علوم پایه، دانشگاه شهرکرد، شهرکرد2. مرکز پژوهشی فناوری نانو، دانشگاه شهرکرد، شهرکرد
author
M
Mardaani
1. گروه فیزیک، دانشکده علوم پایه، دانشگاه شهرکرد، شهرکرد2. مرکز پژوهشی فناوری نانو، دانشگاه شهرکرد، شهرکرد
author
S
Moghbel
1. گروه فیزیک، دانشکده علوم پایه، دانشگاه شهرکرد، شهرکرد
author
text
article
2019
per
In this paper, the electronic transport of a graphene nanoribbon including a bond defect as well as a polyacetylene nanowire, including an extra bond, has been studied based on Green's function technique at the tight-binding approach. The results show that the behavior of electronic conductance is different in resonance and nonresonance cases with respect to variation of bond defect position. The conductance value at the zero energy tunes by variation of defect position, only for the cases which includes double bonds. These changes is more observable especially at the polyacetylene nanowires. The amount of antiresonance shift with respect to bond defect position, in conductance spectrum, strongly depends on type and shape of center wire structure.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
225
230
http://ijpr.iut.ac.ir/article_1198_bdb75cb468606da5b4f3ca263d6c6b91.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.225
Investigation of induced chirp type and its effect on wake field amplitude in propagation of laser pulse through a plasma channel
H
Akou
گروه فیزیک، دانشکده علوم پایه، دانشگاه صنعتی نوشیروانی بابل، بابل
author
text
article
2019
per
In this paper, the propagation of a Gaussian and femtosecond laser pulse through a plasma channel is considered and the amount of induced chirp, as well as it’s type, on laser pulse frequency has been investigated. The group velocity dispersion (GVD) and relativistic effects has been taken into account in propagation equations. It is concluded that the relativistic effect induces positive chirp on laser pulse propagating into plasma channel for every initial chirp, while the GVD effect can induce a negative or positive chirp on laser pulse depending on initial chirp. As the relativistic effect overcomes on GVD in nonlinear region, the induced chirp would be positive. Comparing the results, it is concluded that propagating a laser pulse with initial positive chirp is more effective than a negative and un-chirped pulse for generating a higher wake field.
Iranian Journal of Physics Research
https://www.psi.ir/physics_society_iran_1_home
1682-6957
16
v.
2
no.
2019
231
238
http://ijpr.iut.ac.ir/article_1199_b166e3cd09175b04a41ee8af5308244d.pdf
dx.doi.org/10.18869/acadpub.ijpr.16.2.231