Hossein Afarideh | AmirKabir University Of Technology (original) (raw)
Papers by Hossein Afarideh
Annals of Nuclear Energy
The purpose of the present work is to develop an efficient solution method for the calculation of... more The purpose of the present work is to develop an efficient solution method for the calculation of neutron importance function in fissionable assemblies for all criticality conditions, based on Monte Carlo calculations.
Journal of the Optical Society of Korea
Improved power conversion efficiency of hybrid solar cells with ITO/ZnO seed layer/ZnO NRs/ZnS QD... more Improved power conversion efficiency of hybrid solar cells with ITO/ZnO seed layer/ZnO NRs/ZnS QDs/P3HT/PCBM/Ag structure was obtained by optimizing the growth period of ZnO nanorods (NRs). ZnO NRs were grown using a hydrothermal method on ZnO seed layers, while ZnS quantum dots (QDs) (average thickness about 24 nm) were fabricated on the ZnO NRs by the successive ionic layer adsorption and reaction (SILAR) technique. Morphology, crystalline structure and optical absorption of layers were analyzed by a scanning electron microscope (SEM), X-ray diffraction (XRD) and UV-Visible absorption spectra, respectively. The XRD results implied that ZnS QDs were in the cubic phase (sphalerite). Other experimental results showed that the maximum power conversion efficiency of 4.09% was obtained for a device based on ZnO NR10 under an illumination of one Sun (AM 1.5G, 100mW/cm2100mW/cm^2100mW/cm2 ).
Optik - International Journal for Light and Electron Optics, 2015
ABSTRACT
IET Image Processing, 2015
ABSTRACT In this study, a method to enhance the accuracy of overlapped etched track analysis is p... more ABSTRACT In this study, a method to enhance the accuracy of overlapped etched track analysis is proposed. Counting tracks by eye is not an easy task and automated tracks counting systems are attractive key for this problem. This method supplements the deficiencies of the conventional track analysis method. A computer programme named KoreaTech Track Measurement System written in C++, which is the authors' previous method, has been upgraded. In the proposed track analysis method, the track images captured from solid state nuclear track detectors are geometrically analysed and the number of tracks is counted. A damaged etching track shape can be restored on the track image to improve the analysis accuracy. For track restoration, the effective points are differentiated from the damaged track image. The track image is then restored by estimating the radii (small object removal) or their axis (ellipse, circle and non-circle) using the RANdom sample consensus method. Using the restored track image, the track parameters are obtained from the ellipse and then approximated to the contour of the track image to analyse the track image. Then, the total number of tracks including the overlapped tracks is counted. To verify the proposed track analysis method, experiments using actual etching track images are conducted and the results are discussed.
Zeitschrift für Medizinische Physik, 2012
In this work, the 3D proton dose profile is calculated in a homogenous water phantom using a Mont... more In this work, the 3D proton dose profile is calculated in a homogenous water phantom using a Monte Carlo application developed with the Geant4 toolkit. The effect of the ridge filter material (for SOBP widths of 6, 9 and 12cm) on the homogeneity of the dose distribution, secondary neutron production and beam efficiency are investigated in a single ring wobbling irradiation system. The energy spectrum of secondary neutrons per primary proton at various locations around the phantom surface is calculated. The simulation revealed that most of the produced neutrons are released at slight angles which enable them to reach the patient and consequently to be hazardous. Also, the homogeneity of the dose distribution at the proximal edge of spread out Bragg peak (SOBP) field is deteriorated due to the scattering of protons in the ridge filter. It is found that for reducing the above mentioned destructive effects, usage of a PMMA ridge filter is better than Al one. For a similar value of 9cm water equivalent thickness, beam widening radius of Al at isocenter is twice of PMMA. Furthermore, for uniform irradiation of the target, the beam efficiency of the system for Al is less than of PMMA and also regarding to the secondary neutron production PMMA is a better choice.
Physica E: Low-dimensional Systems and Nanostructures, 2011
The photoresponse behavior of one-dimensional ZnO nanorods grown on ZnO-coated glass substrates v... more The photoresponse behavior of one-dimensional ZnO nanorods grown on ZnO-coated glass substrates via a wet-chemical route at low temperature of 70 1C was investigated. The morphology, structure, composition and chemical state of the prepared nanostructures were characterized by SEM, AFM, XRD and XPS measurements, respectively. The ZnO 1D nanostructures were found to have a hexagonal crystalline structure and grown along the [0 0 1] direction. The nanorods were about 1 mm in length and lower than 100 nm in diameter. The changes in photoresponse of the ZnO nanorods were investigated under different powers of UV illumination and it was also shown that the nanorods have a high sensitivity to UV light. The study suggested that the photoresponse originated from bulk and surface related processes. It is believed that the synthesized ZnO nanorods can be potentially useful in the designing of 1D ZnO-based optoelectronic devices.
IEEE Transactions on Nuclear Science, 2014
In this paper statistical error of count loss in track counting of intensely irradiated solid sta... more In this paper statistical error of count loss in track counting of intensely irradiated solid state nuclear track detectors is studied. Track counting statistics for the chemically etched solid state nuclear track detectors as one of the most commonly used passive detectors are studied in this paper for the counting errors occurred in high densities of nuclear tracks which correspond to high accumulative doses of heavy charged particles, e.g. environmental Alphas of Radon and its daughters. Co-occurrences of two or more particles in close spatial positions cause overlapping of nuclear tracks observable after the etching process and this issue influences the accuracy of counting process. In case of higher densities of nuclear tracks, the overlapping tracks in the track detector correspond to the dead time behavior of paralyzable model in active detectors which leads to miscounting of receiving pulses. However, for both models binomial distribution of Poisson statistics can be taken into account to obtain a relation between the true number of incident particles, those that have formed a nuclear track, and the measured count of detected objects which include both singular tracks and overlapped tracks. This modeling is accredited due to the randomness in the nature of irradiation. It will be shown that in high density nuclear tracks images, where there are significant numbers of overlapping tracks, using the statistical correction of a true form is mandatory. Otherwise the measurement system is not reliable.
Laser and Particle Beams, 2014
ABSTRACT Interaction of a linearly polarized Gaussian laser pulse (at relativistic intensity of 2... more ABSTRACT Interaction of a linearly polarized Gaussian laser pulse (at relativistic intensity of 2.0 × 1020 Wcm−2) with a multi-layer foam (as a near critical density target) attached to a solid layer is investigated by using two-dimensional particle-in-cell simulation. It is found that electrons with longitudinal momentum exceeding the free electrons limit of meca02/2 so-called super-hot electrons can be produced when the direct laser acceleration regime is fulfilled and benefited from self-focusing inside of the subcritical plasma. These electrons penetrate easily through the target and can enhance greatly the sheath field at the rear, resulting in a significant increase in the maximum energy of protons in target normal sheath acceleration regime. The results indicate that the maximum proton energy is enhanced by 2.7 times via using an assembled target arrangement compared to a bare solid target. Furthermore, by demonstration of this assembly, the maximum proton energy is improved beyond the optimum amount achieved by a two-layer target proposed by Sgattoni et al. (2012).
Journal of Applied Physics, 2014
ABSTRACT Propagation of a chirped laser pulse with a circular polarization through an uprising pl... more ABSTRACT Propagation of a chirped laser pulse with a circular polarization through an uprising plasma density profile is studied by using 1D-3V particle-in-cell simulation. The laser penetration depth is increased in an overdense plasma compared to an unchirped pulse. The induced transparency due to the laser frequency chirp results in an enhanced heating of hot electrons as well as increased maximum longitudinal electrostatic field at the back side of the solid target, which is very essential in target normal sheath acceleration regime of proton acceleration. For an applied chirp parameter between 0.008 and 0.01, the maximum amount of the electrostatic field is improved by a factor of 2. Furthermore, it is noticed that for a chirped laser pulse with a0 = 5, because of increasing the plasma transparency length, the laser pulse can penetrate up to about ne ≈ 6nc, where nc is plasma critical density. It shows 63% increase in the effective critical density compared to the relativistic induced transparency regime for an unchirped condition.
Radiation Protection Dosimetry, 2015
In this research, the effect of magnesium (Mg), copper (Cu) and phosphorus (P) impurities on dosi... more In this research, the effect of magnesium (Mg), copper (Cu) and phosphorus (P) impurities on dosimetry response of LiF:Mg,Cu,P phosphors is studied experimentally and by the simulation procedure. In the experimental procedure, LiF:Mg,Cu,P phosphors in the powder form were synthesised by chemical co-precipitation method. After annealing at 2508 8 8 8 8C for 10 min, known amounts of powder were exposed to gamma doses from 0.2 to 1 Gy. The activation energy of the electronic traps for the dosimetric peak at 1508 8 8 8 8C in LiF:Mg,Cu,P crystalline lattice obtained was 0.69 eV. In the simulation study, the role of stated dopants on electronic and structural properties of LiF crystalline lattice is investigated with the WIEN2 K Code. The activation energies of the electronic and hole traps for the dosimetric peak at the same temperature in LiF:Mg,Cu,P crystalline lattice obtained are 0.75 and 3.1 eV, respectively. It is shown that the experimental results are in agreement with simulation results.
2010 6th Iranian Conference on Machine Vision and Image Processing, 2010
Abstract Transmission electron microscopy (TEM) is one of the most useful methods to clarify the ... more Abstract Transmission electron microscopy (TEM) is one of the most useful methods to clarify the structure in micro and Nano materials. We developed a quantitative analysis method for structure identification of Nano materials containing Nano-space by using electron ...
18th International Conference on Nuclear Engineering: Volume 3, 2010
ABSTRACT
Physica Scripta, 2014
ABSTRACT Solid-state quantum dot sensitized solar cells (QDSSCs) were fabricated with zinc sulfid... more ABSTRACT Solid-state quantum dot sensitized solar cells (QDSSCs) were fabricated with zinc sulfide quantum dots (ZnS QDs), which served as the light absorber and the recombination blocking layer simultaneously. ZnS QDs were prepared successfully by a novel successive ionic layer adsorption and reaction technique based on dip-coating (Dip-SILAR). The dependences of the photovoltaic parameters on the number of SILAR cycles (n) were investigated. The cell with n = 6 (particle average size ~9 nm) showed an energy conversion efficiency of 2.72% under the illumination of one sun (AM 1.5, 100 mW cm−2). Here we investigate also the cohesion between ZnS QDs and ZnO film to obtain a well-covering QD layer.
Radiation Measurements, 2015
A correction factor for count losses of different tracks overlapping orders. For the cases imagin... more A correction factor for count losses of different tracks overlapping orders. For the cases imaging the whole area of the detector is not possible. Presenting a statistical generalization method for segmented areas. Giving a relation between the tracks overlapping probabilities and the total tracks.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1996
... B 109/110 (1996) 239-242 B Beam Interactions with Materials & Atoms ELSEVIER Determinatio... more ... B 109/110 (1996) 239-242 B Beam Interactions with Materials & Atoms ELSEVIER Determination of toxic ... Trace elements may be incorporated into hair from the blood circulation as well as through external ... in concentrating many metals (A1, As, Cd, Cr, Cu, Pb, Mn, Hg, Ni, Fe, Zn ...
Journal of Photonics for Energy, 2014
ABSTRACT Zinc sulfide (ZnS) quantum dots were prepared by successive ion layer adsorption and rea... more ABSTRACT Zinc sulfide (ZnS) quantum dots were prepared by successive ion layer adsorption and reaction (SILAR) technique based on spin coating (spin-SILAR). The effect of the number of SILAR cycle (n) on optical and photovoltaic properties was studied. An optimized ZnS quantum dot sensitized solar cell demonstrated maximum power conversion efficiency of 3.58% with a short-circuit current of 10.53 m/cm2 and an open-circuit voltage of 0.58 V under one sun illumination (AM1.5). The results showed that a ZnS QD layer with n = 10 (thickness ~80 nm) can be used as a highly efficient sensitizer for solar cells. The ZnS QD layer acts as a light absorber and a recombination blocking layer in the ITO/ZnO film/ZnS QD/P3HT/PCBM/Ag structure.
Radiation Protection Dosimetry, 2012
By increasing the usage of radiation in all aspects of lives, the human body is becoming more exp... more By increasing the usage of radiation in all aspects of lives, the human body is becoming more exposed to ionising radiation. The purpose of this study is to find the optimal radiation shielding materials to protect humans from the radiation hazards of radiation. Some elements and compounds such as Ag, Bi, Pb, W, BaSO(4) were chosen on the basis of their attenuation coefficients and other characteristics to produce optimised radiation shielding compounds. Multi-objective non-dominated sorting genetic algorithm-II was used to optimise the weight fraction of the elements in compounds based on the dose equivalent rate, shield weight and cost. Consequently, sets of suitable compounds were obtained depending on various applications for energy 0.06 and 0.15 MeV. In addition, optimised lead free compounds were obtained. The results presented in a series of graphs should enable radiation shield designers to choose an appropriate combination according to their requirements.
Radiation Physics and Chemistry, 2002
The bremsstrahlung yields produced by incident electrons on a tantalum converter have been calcul... more The bremsstrahlung yields produced by incident electrons on a tantalum converter have been calculated by using a Monte-Carlo computer code. The tantalum thickness as an X-ray converter was optimized for 2, 2.5, 5, 7.5, and 10 MeV electron beams. The dose distribution in scanning and conveyor direction for both 2 MeV electron and X-ray converted from 2 MeV electron beam have been calculated and compared with experimental results. The economical aspects of low energy electron conversion were discussed as well. r
Radiation Effects and Defects in Solids, 2013
ABSTRACT Track counting algorithms as one of the fundamental principles of nuclear science have b... more ABSTRACT Track counting algorithms as one of the fundamental principles of nuclear science have been emphasized in the recent years. Accurate measurement of nuclear tracks on solid-state nuclear track detectors is the aim of track counting systems. Commonly track counting systems comprise a hardware system for the task of imaging and software for analysing the track images. In this paper, a track recognition algorithm based on 12 defined textual and shape-based features and a neuro-fuzzy classifier is proposed. Features are defined so as to discern the tracks from the background and small objects. Then, according to the defined features, tracks are detected using a trained neuro-fuzzy system. Features and the classifier are finally validated via 100 Alpha track images and 40 training samples. It is shown that principle textual and shape-based features concomitantly yield a high rate of track detection compared with the single-feature based methods.
Annals of Nuclear Energy
The purpose of the present work is to develop an efficient solution method for the calculation of... more The purpose of the present work is to develop an efficient solution method for the calculation of neutron importance function in fissionable assemblies for all criticality conditions, based on Monte Carlo calculations.
Journal of the Optical Society of Korea
Improved power conversion efficiency of hybrid solar cells with ITO/ZnO seed layer/ZnO NRs/ZnS QD... more Improved power conversion efficiency of hybrid solar cells with ITO/ZnO seed layer/ZnO NRs/ZnS QDs/P3HT/PCBM/Ag structure was obtained by optimizing the growth period of ZnO nanorods (NRs). ZnO NRs were grown using a hydrothermal method on ZnO seed layers, while ZnS quantum dots (QDs) (average thickness about 24 nm) were fabricated on the ZnO NRs by the successive ionic layer adsorption and reaction (SILAR) technique. Morphology, crystalline structure and optical absorption of layers were analyzed by a scanning electron microscope (SEM), X-ray diffraction (XRD) and UV-Visible absorption spectra, respectively. The XRD results implied that ZnS QDs were in the cubic phase (sphalerite). Other experimental results showed that the maximum power conversion efficiency of 4.09% was obtained for a device based on ZnO NR10 under an illumination of one Sun (AM 1.5G, 100mW/cm2100mW/cm^2100mW/cm2 ).
Optik - International Journal for Light and Electron Optics, 2015
ABSTRACT
IET Image Processing, 2015
ABSTRACT In this study, a method to enhance the accuracy of overlapped etched track analysis is p... more ABSTRACT In this study, a method to enhance the accuracy of overlapped etched track analysis is proposed. Counting tracks by eye is not an easy task and automated tracks counting systems are attractive key for this problem. This method supplements the deficiencies of the conventional track analysis method. A computer programme named KoreaTech Track Measurement System written in C++, which is the authors' previous method, has been upgraded. In the proposed track analysis method, the track images captured from solid state nuclear track detectors are geometrically analysed and the number of tracks is counted. A damaged etching track shape can be restored on the track image to improve the analysis accuracy. For track restoration, the effective points are differentiated from the damaged track image. The track image is then restored by estimating the radii (small object removal) or their axis (ellipse, circle and non-circle) using the RANdom sample consensus method. Using the restored track image, the track parameters are obtained from the ellipse and then approximated to the contour of the track image to analyse the track image. Then, the total number of tracks including the overlapped tracks is counted. To verify the proposed track analysis method, experiments using actual etching track images are conducted and the results are discussed.
Zeitschrift für Medizinische Physik, 2012
In this work, the 3D proton dose profile is calculated in a homogenous water phantom using a Mont... more In this work, the 3D proton dose profile is calculated in a homogenous water phantom using a Monte Carlo application developed with the Geant4 toolkit. The effect of the ridge filter material (for SOBP widths of 6, 9 and 12cm) on the homogeneity of the dose distribution, secondary neutron production and beam efficiency are investigated in a single ring wobbling irradiation system. The energy spectrum of secondary neutrons per primary proton at various locations around the phantom surface is calculated. The simulation revealed that most of the produced neutrons are released at slight angles which enable them to reach the patient and consequently to be hazardous. Also, the homogeneity of the dose distribution at the proximal edge of spread out Bragg peak (SOBP) field is deteriorated due to the scattering of protons in the ridge filter. It is found that for reducing the above mentioned destructive effects, usage of a PMMA ridge filter is better than Al one. For a similar value of 9cm water equivalent thickness, beam widening radius of Al at isocenter is twice of PMMA. Furthermore, for uniform irradiation of the target, the beam efficiency of the system for Al is less than of PMMA and also regarding to the secondary neutron production PMMA is a better choice.
Physica E: Low-dimensional Systems and Nanostructures, 2011
The photoresponse behavior of one-dimensional ZnO nanorods grown on ZnO-coated glass substrates v... more The photoresponse behavior of one-dimensional ZnO nanorods grown on ZnO-coated glass substrates via a wet-chemical route at low temperature of 70 1C was investigated. The morphology, structure, composition and chemical state of the prepared nanostructures were characterized by SEM, AFM, XRD and XPS measurements, respectively. The ZnO 1D nanostructures were found to have a hexagonal crystalline structure and grown along the [0 0 1] direction. The nanorods were about 1 mm in length and lower than 100 nm in diameter. The changes in photoresponse of the ZnO nanorods were investigated under different powers of UV illumination and it was also shown that the nanorods have a high sensitivity to UV light. The study suggested that the photoresponse originated from bulk and surface related processes. It is believed that the synthesized ZnO nanorods can be potentially useful in the designing of 1D ZnO-based optoelectronic devices.
IEEE Transactions on Nuclear Science, 2014
In this paper statistical error of count loss in track counting of intensely irradiated solid sta... more In this paper statistical error of count loss in track counting of intensely irradiated solid state nuclear track detectors is studied. Track counting statistics for the chemically etched solid state nuclear track detectors as one of the most commonly used passive detectors are studied in this paper for the counting errors occurred in high densities of nuclear tracks which correspond to high accumulative doses of heavy charged particles, e.g. environmental Alphas of Radon and its daughters. Co-occurrences of two or more particles in close spatial positions cause overlapping of nuclear tracks observable after the etching process and this issue influences the accuracy of counting process. In case of higher densities of nuclear tracks, the overlapping tracks in the track detector correspond to the dead time behavior of paralyzable model in active detectors which leads to miscounting of receiving pulses. However, for both models binomial distribution of Poisson statistics can be taken into account to obtain a relation between the true number of incident particles, those that have formed a nuclear track, and the measured count of detected objects which include both singular tracks and overlapped tracks. This modeling is accredited due to the randomness in the nature of irradiation. It will be shown that in high density nuclear tracks images, where there are significant numbers of overlapping tracks, using the statistical correction of a true form is mandatory. Otherwise the measurement system is not reliable.
Laser and Particle Beams, 2014
ABSTRACT Interaction of a linearly polarized Gaussian laser pulse (at relativistic intensity of 2... more ABSTRACT Interaction of a linearly polarized Gaussian laser pulse (at relativistic intensity of 2.0 × 1020 Wcm−2) with a multi-layer foam (as a near critical density target) attached to a solid layer is investigated by using two-dimensional particle-in-cell simulation. It is found that electrons with longitudinal momentum exceeding the free electrons limit of meca02/2 so-called super-hot electrons can be produced when the direct laser acceleration regime is fulfilled and benefited from self-focusing inside of the subcritical plasma. These electrons penetrate easily through the target and can enhance greatly the sheath field at the rear, resulting in a significant increase in the maximum energy of protons in target normal sheath acceleration regime. The results indicate that the maximum proton energy is enhanced by 2.7 times via using an assembled target arrangement compared to a bare solid target. Furthermore, by demonstration of this assembly, the maximum proton energy is improved beyond the optimum amount achieved by a two-layer target proposed by Sgattoni et al. (2012).
Journal of Applied Physics, 2014
ABSTRACT Propagation of a chirped laser pulse with a circular polarization through an uprising pl... more ABSTRACT Propagation of a chirped laser pulse with a circular polarization through an uprising plasma density profile is studied by using 1D-3V particle-in-cell simulation. The laser penetration depth is increased in an overdense plasma compared to an unchirped pulse. The induced transparency due to the laser frequency chirp results in an enhanced heating of hot electrons as well as increased maximum longitudinal electrostatic field at the back side of the solid target, which is very essential in target normal sheath acceleration regime of proton acceleration. For an applied chirp parameter between 0.008 and 0.01, the maximum amount of the electrostatic field is improved by a factor of 2. Furthermore, it is noticed that for a chirped laser pulse with a0 = 5, because of increasing the plasma transparency length, the laser pulse can penetrate up to about ne ≈ 6nc, where nc is plasma critical density. It shows 63% increase in the effective critical density compared to the relativistic induced transparency regime for an unchirped condition.
Radiation Protection Dosimetry, 2015
In this research, the effect of magnesium (Mg), copper (Cu) and phosphorus (P) impurities on dosi... more In this research, the effect of magnesium (Mg), copper (Cu) and phosphorus (P) impurities on dosimetry response of LiF:Mg,Cu,P phosphors is studied experimentally and by the simulation procedure. In the experimental procedure, LiF:Mg,Cu,P phosphors in the powder form were synthesised by chemical co-precipitation method. After annealing at 2508 8 8 8 8C for 10 min, known amounts of powder were exposed to gamma doses from 0.2 to 1 Gy. The activation energy of the electronic traps for the dosimetric peak at 1508 8 8 8 8C in LiF:Mg,Cu,P crystalline lattice obtained was 0.69 eV. In the simulation study, the role of stated dopants on electronic and structural properties of LiF crystalline lattice is investigated with the WIEN2 K Code. The activation energies of the electronic and hole traps for the dosimetric peak at the same temperature in LiF:Mg,Cu,P crystalline lattice obtained are 0.75 and 3.1 eV, respectively. It is shown that the experimental results are in agreement with simulation results.
2010 6th Iranian Conference on Machine Vision and Image Processing, 2010
Abstract Transmission electron microscopy (TEM) is one of the most useful methods to clarify the ... more Abstract Transmission electron microscopy (TEM) is one of the most useful methods to clarify the structure in micro and Nano materials. We developed a quantitative analysis method for structure identification of Nano materials containing Nano-space by using electron ...
18th International Conference on Nuclear Engineering: Volume 3, 2010
ABSTRACT
Physica Scripta, 2014
ABSTRACT Solid-state quantum dot sensitized solar cells (QDSSCs) were fabricated with zinc sulfid... more ABSTRACT Solid-state quantum dot sensitized solar cells (QDSSCs) were fabricated with zinc sulfide quantum dots (ZnS QDs), which served as the light absorber and the recombination blocking layer simultaneously. ZnS QDs were prepared successfully by a novel successive ionic layer adsorption and reaction technique based on dip-coating (Dip-SILAR). The dependences of the photovoltaic parameters on the number of SILAR cycles (n) were investigated. The cell with n = 6 (particle average size ~9 nm) showed an energy conversion efficiency of 2.72% under the illumination of one sun (AM 1.5, 100 mW cm−2). Here we investigate also the cohesion between ZnS QDs and ZnO film to obtain a well-covering QD layer.
Radiation Measurements, 2015
A correction factor for count losses of different tracks overlapping orders. For the cases imagin... more A correction factor for count losses of different tracks overlapping orders. For the cases imaging the whole area of the detector is not possible. Presenting a statistical generalization method for segmented areas. Giving a relation between the tracks overlapping probabilities and the total tracks.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1996
... B 109/110 (1996) 239-242 B Beam Interactions with Materials & Atoms ELSEVIER Determinatio... more ... B 109/110 (1996) 239-242 B Beam Interactions with Materials & Atoms ELSEVIER Determination of toxic ... Trace elements may be incorporated into hair from the blood circulation as well as through external ... in concentrating many metals (A1, As, Cd, Cr, Cu, Pb, Mn, Hg, Ni, Fe, Zn ...
Journal of Photonics for Energy, 2014
ABSTRACT Zinc sulfide (ZnS) quantum dots were prepared by successive ion layer adsorption and rea... more ABSTRACT Zinc sulfide (ZnS) quantum dots were prepared by successive ion layer adsorption and reaction (SILAR) technique based on spin coating (spin-SILAR). The effect of the number of SILAR cycle (n) on optical and photovoltaic properties was studied. An optimized ZnS quantum dot sensitized solar cell demonstrated maximum power conversion efficiency of 3.58% with a short-circuit current of 10.53 m/cm2 and an open-circuit voltage of 0.58 V under one sun illumination (AM1.5). The results showed that a ZnS QD layer with n = 10 (thickness ~80 nm) can be used as a highly efficient sensitizer for solar cells. The ZnS QD layer acts as a light absorber and a recombination blocking layer in the ITO/ZnO film/ZnS QD/P3HT/PCBM/Ag structure.
Radiation Protection Dosimetry, 2012
By increasing the usage of radiation in all aspects of lives, the human body is becoming more exp... more By increasing the usage of radiation in all aspects of lives, the human body is becoming more exposed to ionising radiation. The purpose of this study is to find the optimal radiation shielding materials to protect humans from the radiation hazards of radiation. Some elements and compounds such as Ag, Bi, Pb, W, BaSO(4) were chosen on the basis of their attenuation coefficients and other characteristics to produce optimised radiation shielding compounds. Multi-objective non-dominated sorting genetic algorithm-II was used to optimise the weight fraction of the elements in compounds based on the dose equivalent rate, shield weight and cost. Consequently, sets of suitable compounds were obtained depending on various applications for energy 0.06 and 0.15 MeV. In addition, optimised lead free compounds were obtained. The results presented in a series of graphs should enable radiation shield designers to choose an appropriate combination according to their requirements.
Radiation Physics and Chemistry, 2002
The bremsstrahlung yields produced by incident electrons on a tantalum converter have been calcul... more The bremsstrahlung yields produced by incident electrons on a tantalum converter have been calculated by using a Monte-Carlo computer code. The tantalum thickness as an X-ray converter was optimized for 2, 2.5, 5, 7.5, and 10 MeV electron beams. The dose distribution in scanning and conveyor direction for both 2 MeV electron and X-ray converted from 2 MeV electron beam have been calculated and compared with experimental results. The economical aspects of low energy electron conversion were discussed as well. r
Radiation Effects and Defects in Solids, 2013
ABSTRACT Track counting algorithms as one of the fundamental principles of nuclear science have b... more ABSTRACT Track counting algorithms as one of the fundamental principles of nuclear science have been emphasized in the recent years. Accurate measurement of nuclear tracks on solid-state nuclear track detectors is the aim of track counting systems. Commonly track counting systems comprise a hardware system for the task of imaging and software for analysing the track images. In this paper, a track recognition algorithm based on 12 defined textual and shape-based features and a neuro-fuzzy classifier is proposed. Features are defined so as to discern the tracks from the background and small objects. Then, according to the defined features, tracks are detected using a trained neuro-fuzzy system. Features and the classifier are finally validated via 100 Alpha track images and 40 training samples. It is shown that principle textual and shape-based features concomitantly yield a high rate of track detection compared with the single-feature based methods.