Asghar Ghaderi; arash boochani; Alireza Hojabri; Fatemeh Hajakbari
Abstract
Based on density functional theory calculations, the electronic, optical and thermoelectric properties of WSe2(8,0) and WSeS(8,0) nanotubes have been investigated. The WSe2(8,0) nanotube has 0.2eV energy gap, and this gap is reduced by adding a Se atom to it. The band structure shows that the WSe2(8,0) ...
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Based on density functional theory calculations, the electronic, optical and thermoelectric properties of WSe2(8,0) and WSeS(8,0) nanotubes have been investigated. The WSe2(8,0) nanotube has 0.2eV energy gap, and this gap is reduced by adding a Se atom to it. The band structure shows that the WSe2(8,0) nanotube is p-type semiconductor and WSeS(8,0) compound is n-type. The imaginary part of the dielectric function shows that these two structures have main response to the light in the infrared region and have small optical gaps, while the optical energy loss functions have the lowest values in this energy region. At a temperature of 200 K, the figure of merit coefficient of the WSeS(8,0) nanotube is larger than WSe2(8,0) one, but at high temperatures, the power factor coefficient of the WSe2(8,0) nanotube is higher, which shows that this case is suitable for power generators.
Amirmohammad Beigzadeh; MohammadReza BaSaadat
Abstract
One of the most important methods for dosimetry of ionizing radiation is the use of laser holographic interferometry calorimeters. The temperature increase caused by ionizing radiation depends on the delivered energy, the specific heat capacity of the material, and the mass used as the phantom material ...
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One of the most important methods for dosimetry of ionizing radiation is the use of laser holographic interferometry calorimeters. The temperature increase caused by ionizing radiation depends on the delivered energy, the specific heat capacity of the material, and the mass used as the phantom material in the calorimeter. Among the factors that significantly impact the accuracy of various nuclear radiation calorimeters is the phenomenon of heat transfer in the absorbing material, which forms the core of ionizing radiation interferometry calorimeters. This phenomenon directly affects the measurement of the absorbed dose. In this study, a model has been developed for post-processing the images captured by the camera system of the holographic interferometry calorimeter with a water core exposed to vertical and horizontal irradiation by electron and proton beams.
Elham Emadi; Neda Pourjafari
Abstract
In this article, using quantum hydrodynamic (QHD) model, dust acoustic (DA) shock waves are studied in a quantum dusty plasma containing degenerate electrons, ions and negatively charged dust grains. By employing the reductive perturbation technique, a Kortweg-de Vries-Burgers (KdVB) equation is derived ...
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In this article, using quantum hydrodynamic (QHD) model, dust acoustic (DA) shock waves are studied in a quantum dusty plasma containing degenerate electrons, ions and negatively charged dust grains. By employing the reductive perturbation technique, a Kortweg-de Vries-Burgers (KdVB) equation is derived and solved theoretically and numerically. The hyperbolic tangent (tanh) method is used for theoretical solution. This method is one of the most convenient approaches for solving the nonlinear partial differential equation in dispersive and dissipative systems. The KdVB equation is solved numerically using the fourth-order Runge – Kutta method. It found that when dissipation dominates over dispersion, monotonic shock structure is formed, while in the case of small dissipation, oscillatory shock profile created. The influence of viscosity on DA shock waves shows that shock thickness enhanced with the increase in viscosity. Additionally, the number and height of oscillatory shocks increase as viscosity decreases. The solutions of the KdVB equation studied in a frame moving with the phase velocity of the wave. Considering the boundary conditions, the nonlinear obtained equation rewrite in the form of a dynamical system. In the plane, this system has two fixed points. Investigating the eigen values corresponding to these fixed points indicate that one point is always a saddle, while the other is either a stable focus or a stable node. The phase plane analysis shows that the decrease in the number of spirals shows increase in dissipation.
Behnam Kazempour; Fatemeh Moslemi
Abstract
In this paper, the tunability of a multichannel filter containing magnetized plasma and anisotropic metamaterial in 1D ternary photonic crystal is theoretically investigated and designed in the GHz frequency range. The results show that resonance modes in transmission spectrum of the proposed structure ...
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In this paper, the tunability of a multichannel filter containing magnetized plasma and anisotropic metamaterial in 1D ternary photonic crystal is theoretically investigated and designed in the GHz frequency range. The results show that resonance modes in transmission spectrum of the proposed structure without defining defect layer are created and the structure with a ternary periodicity can act as the multichannel filter. The tunability of the transmission spectrum of the proposed structure by applying an external magnetic field is investigated and shown that channels frequency can be red or blue shifted depending on the orientation of external magnetic field. In addition, the effect of the number of periodicities, the optical axis angle of the anisotropic metamaterial and the incident angle on the filter properties of the channels for both TE and TM polarization is investigated
noushin dadashzadeh
Abstract
Plasma technology is widely applied in various domains, including ozone generation, surface treatment, surface modification, medicine and more. Microwave-induced plasma is a promising and interesting technology due to its unique and versatile properties. These features of microwave plasma is a ...
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Plasma technology is widely applied in various domains, including ozone generation, surface treatment, surface modification, medicine and more. Microwave-induced plasma is a promising and interesting technology due to its unique and versatile properties. These features of microwave plasma is a potential alternative to conventional thermal chemical reactors, provided that specific technical challenges are addressed.
This numerical study investigated the characteristics of a 2.45 GHz microwave plasma generated in argon gas under atmospheric conditions. By varying the input power of the device from 10 to 20 watts within a magnetically confined TM mode, comparative profiles of electron density, electron temperature, and electric field were analyzed. The simulation results demonstrate the production of chemical species within the microwave plasma. High-energy electrons and electron density were identified as primary factors influencing the microwave plasma's properties
Parisa Mahmoudi
Abstract
The field of brain mapping reveals that each region within the nervous system performs specific functions, with neurons in neural networks communicating through complex spatiotemporal patterns. Implementing these neuronal activity patterns is crucial for neuroscience to control neural activity and treat ...
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The field of brain mapping reveals that each region within the nervous system performs specific functions, with neurons in neural networks communicating through complex spatiotemporal patterns. Implementing these neuronal activity patterns is crucial for neuroscience to control neural activity and treat diseases. Researchers use these patterns for targeted neural stimulation of neurons to uncover the secrets of information processing in the brain's intricate networks. Optical neural stimulation, as a powerful tool for manipulating neurons, employs optical modulation techniques to achieve patterned light illumination on neural tissue surfaces. On the other hand, the design of implants that deliver effective, patterned light pulses to target neurons deep within brain tissue is significantly evolving. These tools enable the reconstruction of neuronal activity patterns in both two and three dimensions. This study highlights the necessity of achieving patterned light delivery techniques to neural tissue by introducing various optical stimulation techniques. Subsequently, patterned light implementation through advanced technologies, including scanning lasers, liquid crystal modulators, and digital micromirror modulators, is examined with their unique advantages and challenges. Finally, the notable advancements in fiber optic arrays, waveguides, and micro light-emitting diodes, which collectively pave the way toward more complex and less invasive neural stimulation techniques, are reviewed.