Abdolrasoul Gharaati | Payame Noor University (PNU) (original) (raw)

Papers by Abdolrasoul Gharaati

As a promising quantum material, carbon quantum dots (CQDs) have been widely applied in almost ev... more As a promising quantum material, carbon quantum dots (CQDs) have been widely applied in almost every optoelectronics device and application but the conventional synthesis methods were not eco-friendly due to the use of toxic and heavy metals. We explored an entirely novel approach, utilizing citrus aurantium (bitter orange) as the carbon source and produced CQDs with 4–6 nanometers in diameter and blue, green, and orange emissions. For the purpose of bandgap tuning, we were able to increase the bandgap energy of CQDs by adding a certain amount of urea and polyethylene glycol to the precursor solution in the synthesis procedure. The bandgap energy of CQDs increased from 2.5 to roughly 3.8 eV. Our approach is thoroughly new which brings about a facile, eco-friendly, and low-cost synthesis method.

Acta Physica Polonica A, Nov 1, 2021

In this work, the optical properties of one-dimensional photonic crystal structures which contain... more In this work, the optical properties of one-dimensional photonic crystal structures which contain two dielectrics combined with graphene layers, and Poly (3,4-ethylenedioxythiophene):poly (4styrenesulfonate) (PEDOT:PSS), are reported by using the transfer matrix method. For this purpose, an ideal crystal composed of an alternating layer of SiO2 and Si is considered. The permittivity of the conductive polymer PEDOT:PSS is calculated as a function of the frequency from the Drude-Smith model. When PEDOT:PSS inserts as a defect layer in the two proposed structures with and without graphene layers, the resonant defect mode appears in prohibited region. Results show that the arrangement of graphene layers in the structures tunes the position and height of the resonance mode. The graphene chemical potential and the incident angle of the transverse electric wave also affects the tuning of the PBGs and resonant modes. Therefore, the proposed structures can be beneficial in the fabrication of the tunable low terahertz filters.

Journal of Fusion Energy, Oct 30, 2015

To determine effect of relativistic corrections on the ignition requirements for P11B Fuel, the r... more To determine effect of relativistic corrections on the ignition requirements for P11B Fuel, the rate of energy transfer between ions and electrons and bremsstrahlung loss power are investigated. This research indicates that for overcoming the bremsstrahlung radiation, the electrons temperature must be lower than the ions temperature (less than 100 keV). The bremsstrahlung power is minimized with selecting ratio number of boron ions to number of proton ions in pre-compressed fuel equal 0.2. It determined that the performance of P11B in equilibrium plasma is optimized for temperature of ions in range 300–400 keV depending on the exact value of the Coulomb logarithm in P11B reaction. Reducing the coulomb logarithm all the way to \ln\Lambda = 5$$lnΛ=5 improves the performance of P11B fuel somewhat.

Optics and Photonics Society of Iran, Mar 15, 2015

In this current research, thermoplasmonic properties of gold nanoparticles with different shapes ... more In this current research, thermoplasmonic properties of gold nanoparticles with different shapes such as sphere, core-shell and rod are studied. Here, the interaction of light with gold nanoparticles are modeled using 3D finite element method simulations. First, absorption and extinction cross sections are calculated. Then, the corresponding temperature rise as a result of the absorption of light in gold nanoparticles is calculated by solving the thermal equation simultaneously. The results show that gold nanorods are more appropriate candidates for the potential optothermal applications.

International Journal of Biological Macromolecules, Sep 1, 2023

International Journal of Biological Macromolecules, Jul 1, 2023

Journal of Superconductivity and Novel Magnetism, Dec 13, 2017

In this study, Sendust alloy (Fe85Si9.6Al5.4) was fabricated by mechanical alloying process, and ... more In this study, Sendust alloy (Fe85Si9.6Al5.4) was fabricated by mechanical alloying process, and its crystal structure and magnetic properties were investigated. Sendust alloy has excellent soft magnetic properties and is widely used in different applications. Raw materials (Fe, Si, and Al) were milled by a planetary ball mill at different milling times, from 5 to 20 h. The resulted alloys were annealed at 1373 and 1473 K for 2 h, and the effect of annealing temperature was investigated on the magnetic properties. Crystal structure of the samples was investigated by X-ray diffractometery method. The results indicated that saturation magnetization of 10-h milled sample was at maximum, and it decreased both by increasing milling time and by annealing. These variations were discussed based on phase transformation from ordered to disordered phases and/or vice versa. The maximum saturation magnetization obtained, 156 emu/g, was comparable by those reported for Sendust alloy, which was prepared by other methods. Magnetization–temperature curves of the alloys and annealed ones were recorded by a Faraday balance. Two clear drops were observed on each M-T curve of the as-milled samples that displayed the existence of two different magnetic phases. On the other hand, there is just one drop on the M-T curves of the annealed samples, indicating that these samples were in a less disordered phase.

Current Nanoscience, Dec 14, 2018

The magnetic insulator Fe 3 O 4-modified flaky Fe 85 Si 9.5 Al 5.5 (FeSiAl) powders with signific... more The magnetic insulator Fe 3 O 4-modified flaky Fe 85 Si 9.5 Al 5.5 (FeSiAl) powders with significantly enhanced electromagnetic wave absorption properties in the frequency range of 2-8 GHz were prepared by chemical co-precipitation. X-ray diffraction (XRD) and scanning electron microscopy (SEM) have confirmed the formation of nanoparticles Fe 3 O 4 precipitated on the flake-shaped FeSiAl. The electromagnetic measurements of the modified flakes presents a nearly invariable complex permeability and decreased complex permittivity in the 2-8 GHz, as well as improved impedance matching performance. More importantly, an excellent microwave absorbing performance with the bandwidth (RL<-10 dB) of 5.36 GHz is achieved in modified sample with the thickness of 1.5 mm, which is a promising microwave absorbing material in 2-8 GHz.

European Physical Journal B, Sep 1, 2022

Recent Patents on Nanotechnology

Background: In recent years, severe electromagnetic interference among electronic devices has bee... more Background: In recent years, severe electromagnetic interference among electronic devices has been caused by the unprecedented growth of communication systems. Therefore, microwave absorbing materials are required to relieve these problems by absorbing the unwanted microwave. In the design of microwave absorbers, magnetic nanomaterials have to be used as fine particles dispersed in an insulating matrix. Besides the intrinsic properties of these materials, the structure and morphology are also crucial to the microwave absorption performance of the composite. In this study, Ni-Co- MWCNT composites were synthesized, and the changes in electric permittivity, magnetic permeability, and reflectance loss of the samples were evaluated at frequencies of 2 to 18 GHz. Methods: Nickel-Cobalt-Multi Wall Carbon Nanotubes (MWCNT) composites were successfully synthesized by the co-precipitation chemical method. The structural, morphological, and magnetic properties of the samples were characterized...

Annals of Physics, 2018

The standard Weyl gravity model is investigated.  The stability conditions of the standard Weyl ... more The standard Weyl gravity model is investigated.  The stability conditions of the standard Weyl gravity model are considered.  In the spatially flat Friedmann-Robertson-Walker (FRW) universe, according to the Holographic Dark Energy (HDE) model, the accelerated expansion of the universe is considered.  The suitable conditions of a successful bounce are obtained.

Journal of Fusion Energy, 2015

To determine effect of relativistic corrections on the ignition requirements for P11B Fuel, the r... more To determine effect of relativistic corrections on the ignition requirements for P11B Fuel, the rate of energy transfer between ions and electrons and bremsstrahlung loss power are investigated. This research indicates that for overcoming the bremsstrahlung radiation, the electrons temperature must be lower than the ions temperature (less than 100 keV). The bremsstrahlung power is minimized with selecting ratio number of boron ions to number of proton ions in pre-compressed fuel equal 0.2. It determined that the performance of P11B in equilibrium plasma is optimized for temperature of ions in range 300–400 keV depending on the exact value of the Coulomb logarithm in P11B reaction. Reducing the coulomb logarithm all the way to \ln\Lambda = 5$$lnΛ=5 improves the performance of P11B fuel somewhat.

Physics of Wave Phenomena, 2018

We study the conditions for the anomalous transmission of electromagnetic waves through quantum o... more We study the conditions for the anomalous transmission of electromagnetic waves through quantum overdense plasma. We show that this anomalous transmission is triggered due to the excitation of surface waves, as was observed in the classical overdense plasma. The conditions for the excitation of surface waves are obtained by studying the dispersion relation within the framework of quantum hydrodynamics. The corresponding consequences at the classical limits are consistent with the previous studies. In comparison with the classical regimes, the quantum dispersion curve exhibits an asymptotic behavior which indicates significant effects, in particular, at large wavelengths. Herein, to create the required evanescent waves, we consider the quantum plasma to be placed between two ordinary prisms and dielectrics. The effects of the main parameters, such as the permittivity of the prisms and dielectrics and the Fermi velocity, on the rate of the transmission and the magnetic field propagation are also evaluated.

Physics of Wave Phenomena, 2019

Here, we study the influence of the quantum effects on the Faraday rotation of the electromagneti... more Here, we study the influence of the quantum effects on the Faraday rotation of the electromagnetic waves passed through a magnetized plasma layer. The phenomena of the Faraday rotation consists in the changing of the direction of the wave polarization plane occurred due to the interaction of the magnetic field with the electromagnetic waves. The Faraday rotation also takes place for the waves anomalously transmitted through the magnetized overdense plasma. The anomalous transmission can be described by the mechanism of the surface wave excitations. In the presence of the magnetic field, the dielectric tensor of the magnetized plasma obtains imaginary elements which lead to the rotation of the components of the electric field. However, specifically for the overdense plasma, the quantum effects can be significant and therefore should not be ignored. Here, we are interested in studying the influence of the quantum effects on the Faraday rotation for the overdense plasma. In this regard, we also study the dispersion relation and obtain quantum corrections affecting the conditions for the anomalous transmission of the waves. We show that the results are reduced to the ordinary ones at the classical limit.

International Journal of Fundamental Physical Sciences, 2014

Stau fusion catalyzed fusion proceeds inside the fuel mixture with a wide range of temperature co... more Stau fusion catalyzed fusion proceeds inside the fuel mixture with a wide range of temperature considered. The purpose of this paper is to present a detailed calculation of Stau-atoms and molecules formation rates for different common fusion reactions and the obtained results are compared with each other. Because these formation rates are the most important parameters in the Stau catalyzed fusion method and values of them are directly related to energy production. Our obtained results show that, selection of fusion fuel in determination of formation rate parameter plays an important role. Also, the atom formation rate for , , are is nearly 100 times greater than 3 .

Optik, Apr 1, 2021

Abstract In this paper, the transmission spectrum of a thermal tunable disordered one dimensional... more Abstract In this paper, the transmission spectrum of a thermal tunable disordered one dimensional metallic photonic crystal is examined in both TE and TM polarizations. The structure of this disordered photonic crystal contains of SiO2, Si and Ag layers. The complex refractive index of silver is a function of temperature and wavelength simultaneously. The refractive index of the silicon is also considered as a function of wavelength. Three cases of disorder are considered, single disorder of SiO2 and Si separately and double disorder (SiO2 and Si simultaneously). It has been found that at a constant degree of disorder and incident angle the transmission mode shifts toward the larger wavelength as the temperature gets increased. Furthermore, by increasing the degree of disorder at a given temperature and incident angle, the defect mode shift towards the shorter wavelength when the disorder of SiO2 is considered, however, the wavelength shift has no definite order in two cases Si layer and double disorder.

Optik, Apr 1, 2021

Abstract In this paper, the transmission spectrum of a thermal tunable disordered one dimensional... more Abstract In this paper, the transmission spectrum of a thermal tunable disordered one dimensional metallic photonic crystal is examined in both TE and TM polarizations. The structure of this disordered photonic crystal contains of SiO2, Si and Ag layers. The complex refractive index of silver is a function of temperature and wavelength simultaneously. The refractive index of the silicon is also considered as a function of wavelength. Three cases of disorder are considered, single disorder of SiO2 and Si separately and double disorder (SiO2 and Si simultaneously). It has been found that at a constant degree of disorder and incident angle the transmission mode shifts toward the larger wavelength as the temperature gets increased. Furthermore, by increasing the degree of disorder at a given temperature and incident angle, the defect mode shift towards the shorter wavelength when the disorder of SiO2 is considered, however, the wavelength shift has no definite order in two cases Si layer and double disorder.

As a promising quantum material, carbon quantum dots (CQDs) have been widely applied in almost ev... more As a promising quantum material, carbon quantum dots (CQDs) have been widely applied in almost every optoelectronics device and application but the conventional synthesis methods were not eco-friendly due to the use of toxic and heavy metals. We explored an entirely novel approach, utilizing citrus aurantium (bitter orange) as the carbon source and produced CQDs with 4–6 nanometers in diameter and blue, green, and orange emissions. For the purpose of bandgap tuning, we were able to increase the bandgap energy of CQDs by adding a certain amount of urea and polyethylene glycol to the precursor solution in the synthesis procedure. The bandgap energy of CQDs increased from 2.5 to roughly 3.8 eV. Our approach is thoroughly new which brings about a facile, eco-friendly, and low-cost synthesis method.

Acta Physica Polonica A, Nov 1, 2021

In this work, the optical properties of one-dimensional photonic crystal structures which contain... more In this work, the optical properties of one-dimensional photonic crystal structures which contain two dielectrics combined with graphene layers, and Poly (3,4-ethylenedioxythiophene):poly (4styrenesulfonate) (PEDOT:PSS), are reported by using the transfer matrix method. For this purpose, an ideal crystal composed of an alternating layer of SiO2 and Si is considered. The permittivity of the conductive polymer PEDOT:PSS is calculated as a function of the frequency from the Drude-Smith model. When PEDOT:PSS inserts as a defect layer in the two proposed structures with and without graphene layers, the resonant defect mode appears in prohibited region. Results show that the arrangement of graphene layers in the structures tunes the position and height of the resonance mode. The graphene chemical potential and the incident angle of the transverse electric wave also affects the tuning of the PBGs and resonant modes. Therefore, the proposed structures can be beneficial in the fabrication of the tunable low terahertz filters.

Journal of Fusion Energy, Oct 30, 2015

To determine effect of relativistic corrections on the ignition requirements for P11B Fuel, the r... more To determine effect of relativistic corrections on the ignition requirements for P11B Fuel, the rate of energy transfer between ions and electrons and bremsstrahlung loss power are investigated. This research indicates that for overcoming the bremsstrahlung radiation, the electrons temperature must be lower than the ions temperature (less than 100 keV). The bremsstrahlung power is minimized with selecting ratio number of boron ions to number of proton ions in pre-compressed fuel equal 0.2. It determined that the performance of P11B in equilibrium plasma is optimized for temperature of ions in range 300–400 keV depending on the exact value of the Coulomb logarithm in P11B reaction. Reducing the coulomb logarithm all the way to \ln\Lambda = 5$$lnΛ=5 improves the performance of P11B fuel somewhat.

Optics and Photonics Society of Iran, Mar 15, 2015

In this current research, thermoplasmonic properties of gold nanoparticles with different shapes ... more In this current research, thermoplasmonic properties of gold nanoparticles with different shapes such as sphere, core-shell and rod are studied. Here, the interaction of light with gold nanoparticles are modeled using 3D finite element method simulations. First, absorption and extinction cross sections are calculated. Then, the corresponding temperature rise as a result of the absorption of light in gold nanoparticles is calculated by solving the thermal equation simultaneously. The results show that gold nanorods are more appropriate candidates for the potential optothermal applications.

International Journal of Biological Macromolecules, Sep 1, 2023

International Journal of Biological Macromolecules, Jul 1, 2023

Journal of Superconductivity and Novel Magnetism, Dec 13, 2017

In this study, Sendust alloy (Fe85Si9.6Al5.4) was fabricated by mechanical alloying process, and ... more In this study, Sendust alloy (Fe85Si9.6Al5.4) was fabricated by mechanical alloying process, and its crystal structure and magnetic properties were investigated. Sendust alloy has excellent soft magnetic properties and is widely used in different applications. Raw materials (Fe, Si, and Al) were milled by a planetary ball mill at different milling times, from 5 to 20 h. The resulted alloys were annealed at 1373 and 1473 K for 2 h, and the effect of annealing temperature was investigated on the magnetic properties. Crystal structure of the samples was investigated by X-ray diffractometery method. The results indicated that saturation magnetization of 10-h milled sample was at maximum, and it decreased both by increasing milling time and by annealing. These variations were discussed based on phase transformation from ordered to disordered phases and/or vice versa. The maximum saturation magnetization obtained, 156 emu/g, was comparable by those reported for Sendust alloy, which was prepared by other methods. Magnetization–temperature curves of the alloys and annealed ones were recorded by a Faraday balance. Two clear drops were observed on each M-T curve of the as-milled samples that displayed the existence of two different magnetic phases. On the other hand, there is just one drop on the M-T curves of the annealed samples, indicating that these samples were in a less disordered phase.

Current Nanoscience, Dec 14, 2018

The magnetic insulator Fe 3 O 4-modified flaky Fe 85 Si 9.5 Al 5.5 (FeSiAl) powders with signific... more The magnetic insulator Fe 3 O 4-modified flaky Fe 85 Si 9.5 Al 5.5 (FeSiAl) powders with significantly enhanced electromagnetic wave absorption properties in the frequency range of 2-8 GHz were prepared by chemical co-precipitation. X-ray diffraction (XRD) and scanning electron microscopy (SEM) have confirmed the formation of nanoparticles Fe 3 O 4 precipitated on the flake-shaped FeSiAl. The electromagnetic measurements of the modified flakes presents a nearly invariable complex permeability and decreased complex permittivity in the 2-8 GHz, as well as improved impedance matching performance. More importantly, an excellent microwave absorbing performance with the bandwidth (RL<-10 dB) of 5.36 GHz is achieved in modified sample with the thickness of 1.5 mm, which is a promising microwave absorbing material in 2-8 GHz.

European Physical Journal B, Sep 1, 2022

Recent Patents on Nanotechnology

Background: In recent years, severe electromagnetic interference among electronic devices has bee... more Background: In recent years, severe electromagnetic interference among electronic devices has been caused by the unprecedented growth of communication systems. Therefore, microwave absorbing materials are required to relieve these problems by absorbing the unwanted microwave. In the design of microwave absorbers, magnetic nanomaterials have to be used as fine particles dispersed in an insulating matrix. Besides the intrinsic properties of these materials, the structure and morphology are also crucial to the microwave absorption performance of the composite. In this study, Ni-Co- MWCNT composites were synthesized, and the changes in electric permittivity, magnetic permeability, and reflectance loss of the samples were evaluated at frequencies of 2 to 18 GHz. Methods: Nickel-Cobalt-Multi Wall Carbon Nanotubes (MWCNT) composites were successfully synthesized by the co-precipitation chemical method. The structural, morphological, and magnetic properties of the samples were characterized...

Annals of Physics, 2018

The standard Weyl gravity model is investigated.  The stability conditions of the standard Weyl ... more The standard Weyl gravity model is investigated.  The stability conditions of the standard Weyl gravity model are considered.  In the spatially flat Friedmann-Robertson-Walker (FRW) universe, according to the Holographic Dark Energy (HDE) model, the accelerated expansion of the universe is considered.  The suitable conditions of a successful bounce are obtained.

Journal of Fusion Energy, 2015

To determine effect of relativistic corrections on the ignition requirements for P11B Fuel, the r... more To determine effect of relativistic corrections on the ignition requirements for P11B Fuel, the rate of energy transfer between ions and electrons and bremsstrahlung loss power are investigated. This research indicates that for overcoming the bremsstrahlung radiation, the electrons temperature must be lower than the ions temperature (less than 100 keV). The bremsstrahlung power is minimized with selecting ratio number of boron ions to number of proton ions in pre-compressed fuel equal 0.2. It determined that the performance of P11B in equilibrium plasma is optimized for temperature of ions in range 300–400 keV depending on the exact value of the Coulomb logarithm in P11B reaction. Reducing the coulomb logarithm all the way to \ln\Lambda = 5$$lnΛ=5 improves the performance of P11B fuel somewhat.

Physics of Wave Phenomena, 2018

We study the conditions for the anomalous transmission of electromagnetic waves through quantum o... more We study the conditions for the anomalous transmission of electromagnetic waves through quantum overdense plasma. We show that this anomalous transmission is triggered due to the excitation of surface waves, as was observed in the classical overdense plasma. The conditions for the excitation of surface waves are obtained by studying the dispersion relation within the framework of quantum hydrodynamics. The corresponding consequences at the classical limits are consistent with the previous studies. In comparison with the classical regimes, the quantum dispersion curve exhibits an asymptotic behavior which indicates significant effects, in particular, at large wavelengths. Herein, to create the required evanescent waves, we consider the quantum plasma to be placed between two ordinary prisms and dielectrics. The effects of the main parameters, such as the permittivity of the prisms and dielectrics and the Fermi velocity, on the rate of the transmission and the magnetic field propagation are also evaluated.

Physics of Wave Phenomena, 2019

Here, we study the influence of the quantum effects on the Faraday rotation of the electromagneti... more Here, we study the influence of the quantum effects on the Faraday rotation of the electromagnetic waves passed through a magnetized plasma layer. The phenomena of the Faraday rotation consists in the changing of the direction of the wave polarization plane occurred due to the interaction of the magnetic field with the electromagnetic waves. The Faraday rotation also takes place for the waves anomalously transmitted through the magnetized overdense plasma. The anomalous transmission can be described by the mechanism of the surface wave excitations. In the presence of the magnetic field, the dielectric tensor of the magnetized plasma obtains imaginary elements which lead to the rotation of the components of the electric field. However, specifically for the overdense plasma, the quantum effects can be significant and therefore should not be ignored. Here, we are interested in studying the influence of the quantum effects on the Faraday rotation for the overdense plasma. In this regard, we also study the dispersion relation and obtain quantum corrections affecting the conditions for the anomalous transmission of the waves. We show that the results are reduced to the ordinary ones at the classical limit.

International Journal of Fundamental Physical Sciences, 2014

Stau fusion catalyzed fusion proceeds inside the fuel mixture with a wide range of temperature co... more Stau fusion catalyzed fusion proceeds inside the fuel mixture with a wide range of temperature considered. The purpose of this paper is to present a detailed calculation of Stau-atoms and molecules formation rates for different common fusion reactions and the obtained results are compared with each other. Because these formation rates are the most important parameters in the Stau catalyzed fusion method and values of them are directly related to energy production. Our obtained results show that, selection of fusion fuel in determination of formation rate parameter plays an important role. Also, the atom formation rate for , , are is nearly 100 times greater than 3 .

Optik, Apr 1, 2021

Abstract In this paper, the transmission spectrum of a thermal tunable disordered one dimensional... more Abstract In this paper, the transmission spectrum of a thermal tunable disordered one dimensional metallic photonic crystal is examined in both TE and TM polarizations. The structure of this disordered photonic crystal contains of SiO2, Si and Ag layers. The complex refractive index of silver is a function of temperature and wavelength simultaneously. The refractive index of the silicon is also considered as a function of wavelength. Three cases of disorder are considered, single disorder of SiO2 and Si separately and double disorder (SiO2 and Si simultaneously). It has been found that at a constant degree of disorder and incident angle the transmission mode shifts toward the larger wavelength as the temperature gets increased. Furthermore, by increasing the degree of disorder at a given temperature and incident angle, the defect mode shift towards the shorter wavelength when the disorder of SiO2 is considered, however, the wavelength shift has no definite order in two cases Si layer and double disorder.

Optik, Apr 1, 2021

Abstract In this paper, the transmission spectrum of a thermal tunable disordered one dimensional... more Abstract In this paper, the transmission spectrum of a thermal tunable disordered one dimensional metallic photonic crystal is examined in both TE and TM polarizations. The structure of this disordered photonic crystal contains of SiO2, Si and Ag layers. The complex refractive index of silver is a function of temperature and wavelength simultaneously. The refractive index of the silicon is also considered as a function of wavelength. Three cases of disorder are considered, single disorder of SiO2 and Si separately and double disorder (SiO2 and Si simultaneously). It has been found that at a constant degree of disorder and incident angle the transmission mode shifts toward the larger wavelength as the temperature gets increased. Furthermore, by increasing the degree of disorder at a given temperature and incident angle, the defect mode shift towards the shorter wavelength when the disorder of SiO2 is considered, however, the wavelength shift has no definite order in two cases Si layer and double disorder.