Hamid R DehghanpourTafresh University · Physics Department
Hamid R Dehghanpour
Assistant Professor
About
45
Publications
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163
Citations
Citations since 2017
Introduction
Additional affiliations
March 2013 - present
March 2013 - present
March 2007 - present
Publications
Publications (45)
Silicon, as the most abundant element in the earth's crust and the most common material used in electronic and optical equipment, has attracted the attention of many individuals to change the properties of this material, improving its electronic and optical properties. One of these efforts relies on the reduction of surface reflection by making use...
A TEA-CO2 laser based DIAL is employed to determine the range resolved hexafluoride (SF6) concentration. An algorithm is developed here in favor of the lidar signal processing to improve the data assessment against the undesired ringing effect. The latter is known as a lidar waveform defect that arises from multiple reflections of transmission line...
Electromagnetic radiation on the suspension of silver-water nanoparticles was simulated using Maxwell equations and the phenomenological equation of extinction crosssection and application of appropriate boundary conditions for nanoparticles with spherical geometry. The outputs of this simulation (extinction coefficient in different conditions) wer...
In this paper the Fourier transform combined with Adomian decomposition method (FTADM) is applied for solving the squeezed unsteady flow between parallel plates influenced by an inclined magnetic field. By moving these plates toward each other, the squeezing flow which is perpendicular to the plates is appeared. We assume that inclination varies fr...
Selective dissociation of sulfur hexafluoride molecules was simulated using single-mode and multi-mode carbon dioxide lasers using a two-layer feedforward neural network with 4 and 2nodes in the first and second layers, respectively. Existing experimental results [1] were used to train and verify neural networks. Simulation was performed using MATL...
In many modern sciences, electron transfer is required, such as electron microscopes, microwaves, and screens. There have been numerous reports of the formation of microstructures on silicon surfaces using lasers in halogen-containing media and their optical, electrical and other physical properties. A silicon microstructured field emitter is model...
In this study, a laboratory pilot of an OSL dosimetry system was designed and built for use in remote radiotherapy dosimetry. In the design and construction of this dosimeter, optical and electronic noise removal considerations have been considered. Due to the fact that each dosimetry system needs calibration steps in order to have the ability to d...
In this paper the Fourier transform combined with Adomian decomposition method (FTADM) is applied for solving the squeezed unsteady flow between parallel plates influenced by an inclined magnetic field. By moving these plates toward each other, the squeezing flow which is perpendicular to the plates is appeared. We assume that inclination varies fr...
In this work, the growth and characterization of potassium chloride crystals containing diamond nanoparticles has been performed. The crystals were grown by the Czochralski method and the doped samples contained 0.5, 1 and 1.5% impurities of diamond nanoparticles. The crystals were characterized by X ray diffraction (XRD), Fourier transform infra-r...
In this work, the generation of Al-Cu content nanocomposites were done by using Pulsed Nd:YAG laser (1064 nm) ablation in water confined plasma. At first, the Al content nanoparticles were fabricated and characterized. Then, copper target was merged into the Al content suspension and the laser irradiation on the target was done. On the other hand,...
Iron oxide (Fe3O4) nanoparticles are synthesized using the chemical co-precipitation method. Changing factors such as surfactant, pH, and molar ratio of ferrous to ferric ions effects the size and magnetic properties of the nanoparticles significantly. The synthesized nanoparticles are characterized using scanning electron microscopy (SEM), X-ray d...
Plasmonic production of the nanoparticles is an attractive matter for the research. A significant part of the plasmonic nanoparticle generation methods is based on the created of the nanobubbles by pulsed laser irradiation in the liquid medium. Here, the generation of Ag nanoparticles produced in vicinity of the nanobubbles created by pulsed femtos...
Fe3O4 magnetic nanoparticles have been synthesized successfully in chemical co-precipitation method and coated with oleic and citric acids, separately. The crystalline sizes are determined by the Debye-
Scherer equation with X-ray powder diffraction data. As a result, the mean crystalline size and lattice constant of Fe3O4 nanoparticles respectivel...
Anew approach based on the Adomian decomposition and the Fourier transform is introduced. The method suggests a solution for the well-known magneto-hydrodynamic (MHD) Jeffery-Hamel equation. Results of Adomian decomposition method combined with Fourier transform are compared with exact and numerical methods. TheFTADMas an exclusive and new method s...
This work reports a study of the structure and magnetic behavior of NiFe2O4 ferromagnetic oxide nanoparticles synthesized by the combustion method. The structural and magnetic properties of nanoparticles after mechanical milling are investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, transmission electron microscope. T...
Silicon is one of the most important semiconductor materials which there are many researches about it and there are many researches works under operation on it now. One of the interesting matters of those researches is changing the surface properties of the silicon in order to obtain different applications of it. In this way, creating self-organize...
In this work growth and characterization of potassium chloride with nanodiamond is studied. Crystals were grown using Czochralski crystal growth method. KCl crystals are doped with 0.5, 1 and 1.5 percent nanodiamond (ND) impurities. Breaking cross sections of the pure and doped crystals were characterized by scanning electron microscopy (SEM). As a...
The nano core-shell can be generated in a proper liquid medium under controlled laser ablation condition. In this work, the formation of core-shell structure by laser ablation of two different targets was modeled based on the Smoluchowski approach. In this model, the movement and aggregation of the ablated fragments ejected from the targets were in...
The combustion method has been utilized to generate nickel spinel ferrite nanoparticles. The nanoparticles were generated on two different molarities of Fe (NO3)3. 9 H2O and Ni (NO3 )2. 6 H2 O. The generated nanoparticles were ball milled for 3 h. Physical and chemical properties of the nanoparticles were characterized by X-ray diffraction (XRD), F...
Creation a self-organized microstructure on the
silicon content surface by laser irradiation in halide ambient
atmosphere is a well-known phenomenon. One of the most
significant parameters on the process is the pressure of the
ambient gas. Although there are many works about
experimental validation of the pressure dependence of the
process but theo...
In this work, Al nanoparticles are generated using Q switched pulsed Nd:yttrium aluminum garnet laser (1064 and 532 nm) ablation in a water confined plasma at 3, 5, and 10 min exposure times. The aim is to investigate the wavelength and exposure time dependence of nanoparticle formation mechanisms. Nanoparticles fabricated by both wavelengths show...
The combustion method has been utilized to generate cobalt spinel ferrite nanoparticles. The generated nanoparticles were ball milled for different times. Physical and chemical properties of the nanoparticles were characterized by X- ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), and v...
In this work, Al nanoparticles were generated using second harmonic of pulsed Nd:YAG laser (532 nm) ablation in water confined plasma at 5 min exposure time. Nanoparticles were characterized by transmission electron microscopy (TEM), selected area electron diffraction (SAED) and the dynamic light scattering (DLS). Nanoparticles had spherical shape...
The combustion and ultrasonic bath methods have been utilized to generate nickel spinel ferrite nanoparticles. Physical and chemical properties of generated nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and vibrating sample magnetometer (VSM). Between the nanoparticles generated by ment...
In this work, Al nanoparticles were generated using Pulsed Nd: YAG laser (1064 nm) ablation in water confined plasma. Productions were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and selected area electron diffraction (SAED). Laser ablation of the Al target in deionized water leads to fabrication core-shell type...
Glass surface modification is one of the processes which changes its physical properties. Changing optical
property is a significant effect of surface modification. Among the surface modification methods, laser surface modification is attractive for researchers. Here, SiO2 glass target was irradiated by Q-switched Nd:YAG laser (1064 nm) in SF6 atmo...
Photonic crystals containing defects produce enhanced Faraday rotation. They have opened up the possibility of fabricating very compact magneto-optics structures. In this work, we have designed a two-dimensional photonic crystal waveguide for use in optical packaging and integrated optical circuits. For design purposes, a temporal coupled mode theo...
In this work, the authors have generated Mn ferrite nanoparticles by Nd:YAG (1064 nm) laser irradiation in distilled water. Then, they have investigated shape and size of nanoparticles by transmission electron microscopy and atomic force microscope. Chemical composition of nanoparticle was characterized using dispersive x-ray energy, and the magnet...
We have generated Nd-Fe-B-C nanoparticles by Nd:YAG (1064 nm) laser irradiation in distilled water. Exposure times were 1, 5, and 10 min. Characterization of such nanoparticles in terms of their size distribution, shape, and chemical composition was carried out by transmission electron microscopy, energy-dispersive X-rays, and Fourier transform inf...
We generate Mn–ferrite nanoparticles (NPs) by Nd:YAG (1064 nm) laser irradiation in distilled water. We characterize such NPs in terms of the size distribution, shape and chemical composition using transmission electron microscopy (TEM), energy-dispersive X rays (EDS), and Fourier-transform infrared spectroscopy (FTIR). Using a magnetic force micro...
CO2 laser (10.6 µm) is a well�known infrared coherent light source as a tool in surgery. At this wavelength there is a high absorbance coefficient (860 cm–1 ), because of vibration mode resonance of H2O molecules. Therefore, the majority of the irradiation energy is absorbed in the tissue and the temperature of the tissue rises as a function of pow...
CO2 laser (10.6 µm) is a well�known infrared coherent light source as a tool in surgery. At this wavelength there is a high absorbance coefficient (860 cm–1 ), because of vibration mode resonance of H2O molecules. Therefore, the majority of the irradiation energy is absorbed in the tissue and the temperature of the tissue rises as a function of pow...
In this work, (Nd–Fe–B–C) magnetic nanoparticles are generated by pulses of Nd:YAG laser irradiation on the (Nd–Fe–B–C) magnetic target in distilled water. Exposure times were 1, 5, and 10 min. Percentages of elements in a bulk sample and nanoparticles are investigated by energy-dispersive X rays (EDX). Mean particle sizes of the nanosamples are an...
In this work, Nd -Fe- B-C magnetic nanoparticles were generated by pulse of Nd:YAG Laser irradiation on the Nd -Fe- B-C magnetic target in Distilled water. Percentages of Element in bulk and nano-particles were investigated by energy- dispersive X-ray (EDAX) .mean particle sizes of the samples were analyzed by transmission electron microscope (TEM)...
In this work, we have generated Mn Ferrite nanoparticles by Nd:YAG(1064 nm)laser irradiation in distilled water. Then, we have investigated shape and size of nanoparticles by TEM(Transmission electron microscopy).Chemical composition of nanoparticle was characterized using EDX(Dispersive x-ray energy)and the magnetic properties of them have studied...
In this work, the evidence of SF6 gas decomposition at the vicinity of SiO2 glass has been investigated using various laser wavelengths: at 193, 248, 532 and 1064nm. It was shown that SiF4 gas and S2F10 clusters were simultaneously created during ArF excimer laser irradiation, while no by-products were seen in the irradiation cell using Q-switched...
At low pressures up to 0.1 mbar, the evidence of simultaneous SF 6 gas decomposition and the morphology alteration on amorphous SiO2 glass have been investigated using various laser irradiations at typical wavelengths, i.e., ultraviolet (UV; 193 nm), visible (532 nm), and near infrared (NIR; 1064 nm). The instrumental micro-analysis of the surface...
The nano core-shell can be generated in the water under controlled exposure
conditions using Q-SW Nd:YAG laser shots at 1064 nm. At first, the gold target was irradiated in water to generate nano gold particles. Then the silver target was immersed into water-gold suspension to be irradiated by laser shots too. The nano core-shells Ag (core)-Gold (...
Here, the excimer laser irradiation on the glass surface in SF6 ambient gas has been investigated. In spite of the glass UV- ablation in air the self-organized micro-structuring takes place. In fact it is due to surface ablation leading to oxygen and electron ejection from the surface and because of large collisional cross section those make SF6 de...
ArF excimer laser radiation on Si surface at controlled SF6 atmosphere creates a microstructure whose alteration at various UV doses and SF6 pressures are investigated in this work. Moreover, a rigorous model has been presented here regarding the experiments based on the micro-fluid mechanical properties of molten silicon layer and the subsequent m...
In this work, the photon distribution of He:Ne laser within dermis tissue is studied. The dermis as a highly scattering media
was irradiated by a low power laser. The photon densities as well as the corresponding isothermal contours were obtained by
two different numerical methods, i.e., Lambert-Beer and Welch. The results were compared to that of...
An axially symmetric compressible flow past a flat-nosed cylinder at high velocity and low pressure with shock wave is simulated using the Navier-Stokes equation and the Boltzmann equation. The results of the two simulations (Navier-Stokes and Boltzmann) are compared in terms of different Knudsen numbers. In the region close to the shock wave the d...
Questions
Question (1)
We have generated Al nanoparticles by Nd:YAG laser in water after that we have irradiated a Cu target by that laser in the water+ Al nanoparticles suspension, the TEM pictures of the resulting material is an uniform region with unregular boundary. what is the resulting material
Projects
Projects (2)
Electrogravity is a promising phenomenon in flight instrument such as airplane and so on. Better investigation of it needs a good simulation of some kind of electrogravity vehicles based on electromagnetic and gravity equations. In this project the main goal is characterization of the best differential equations and simultaneous solution of them by COMSOL.
