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      • KCI등재

        Synthesis and Exploitation in Solar Cells of Hydrothermally Grown ZnO Nanorods Covered by ZnS Quantum Dots

        Masood Mehrabian,Hossein Afarideh,Kavoos Mirabbaszadeh,Li Lianshan,Tang Zhiyong 한국광학회 2014 Current Optics and Photonics Vol.18 No.4

        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, 100 mW/cm2).

      • KCI등재

        Comparison of nano/micro lead, bismuth and tungsten on the gamma shielding properties of the flexible composites against photon in wide energy range (40 keV – 662 keV)

        Mansour Asgari,Hossein Afarideh,Hassan Ghafoorifard,Eskandar Asadi Amirabadi 한국원자력학회 2021 Nuclear Engineering and Technology Vol.53 No.12

        In the radiation protection application, the metal-polymer composites have been developed for theirradiation shielding properties. In this research, the elastomer composites doped by 10 mm and100nm sizeof lead, bismuth and tungsten particles as filler with 30 and 60 wt percentages were prepared. To surveythe shielding properties of the polymer composites using gamma-ray emitted from 152Eu and 137Cssources, the gamma flux was measured by using NaI(Tl) detector, then the linear attenuation coefficientwas calculated. Also, the Monte Carlo simulation (MCs) method was used. The results showed a directrelationship between the linear attenuation coefficients of the absorbent and filler ratio. Also, thedecrease in the particle size of the shielding material in each weight percentage improved the radiationshielding features. When the dimension of the particles was in the order of nano-size, more attenuationwas achieved. At low energies used for medical diagnostic X-ray applications due to the predominance ofthe photoelectric effect, bismuth and lead were suitable selection as filler.

      • KCI등재

        Dosimetric and Microdosimetric Characteristics of 9.6 to 30α-MeV Proton Beams

        Mitra Ghergherehchi,채종서,Hossein Afarideh,Ahmad Mohammadzadeh 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.5

        High and intermediate energy protons are not able to directly form a track in an etch detector (TED). Such detectors can, however, be used for the detection and dosimetry of beams of these particles through the registration of secondary charged particles with sufficiently high values of linear energy transfer (LET).Intermediate energy protons (10 to 30 MeV) with low LET values ranging from 5.87 down to 2.40 keV/탆 are considered. Although the LET values are low, this energy range seems to be sufficient to create secondary particles with much higher LET values through nuclear reactions in the irradiated matter. This phenomenon can modify the characteristics of the energy transfer process due to these particles, and it should be taken into account when such particles are used for radiobiology and/or radiotherapy studies. The importance of these secondary particles was studied experimentally by means of a LET spectrometer based on a chemically etched track detector, in which the tracks of the primary protons are not revealed. These studies were performed with protons whose primary energies were in the range of about 10 to 30 MeV, which are available at the Cyclotron Accelerator Department of Nuclear Research Center for Agriculture and Medicine (NRCAM) in Karaj, Iran. The microdosimetric distributions of the secondary particles mentioned above are presented, and their contributions to the absorbed dose of the primary protons are estimated. The contribution of the secondary particle dose increases with decreasing proton energy. The importance of this phenomenon in some applications is discussed. The origin of the secondary particles in interactions with protons having high and intermediate energies due to various nuclear reactions was calculated by using the Alice computer code. There is good agreement between the experimentally obtained and theoretically calculated results.

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        Real-time 14N NQR-based sodium nitrite analysis in a noisy field

        Sharifi Mohammad Saleh,송호승,Afarideh Hossein,미트라게게르치,Simiari Mehdi 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.12

        Noise and Radio-frequency interference or RFI causes a significant restriction on the Free induction Decay or FID signal detection of the Nuclear Quadrupole Resonance procedure. Therefore, using this method in non-isolated environments such as industry and ports requires extraordinary measures. For this purpose, noise reduction algorithms and increasing signal-to-noise-and-interference ratio or SNIR have been used. In this research, sodium nitrite has been used as a sample and algorithms have been tested in a non-isolated environment. The resonant frequencies for the 150 g of test sample were measured at 303 K at about 1 MHz and 3.4 MHz. The main novelty in this study was, (1) using two types of antennas in the receiver to improve adaptive noise and interference cancellation, (2) using a separate helical antenna in the transmitter to eliminate the duplexer, (3) estimating the noise before sending the pulse to calculate the weighting factors and reduce the noise by adaptive noise cancellation, (3) reject the interference by blanking algorithm, (4) pulse integration in the frequency domain to increase the SNR, and (5) increasing the detection speed by new pulse integration technique. By interference rejection and noise cancellation, the SNIR is improved to 9.24 dB at 1 MHz and to 7.28 dB at 3.4 MHz, and by pulse integration 44.8 dB FID signal amplification is achieved, and the FID signals are detected at 1.057 MHz and 3.402 MHz at room temperature

      • KCI등재

        Artificial neural network-based sodium nitrite NQR analysis in an urban noisy environment

        Mohammad Saleh Sharifi A. M.,Hossein Afarideh,Mitra Ghergherehchi,Mehdi Simiari 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.83 No.3

        Using the nuclear quadrupole resonance procedure in non-shielded environments requires special measures. For this purpose, noise reduction and interference suppression algorithms have been used to increase signal-to-noise and interference ratio or SNIR. For this aim, two types of antennas are considered, the ferrite core coil antenna as the main antenna receives the free induction decay or FID signal, radio frequency interference or RFI, and noise, and the omnidirectional auxiliary antenna receives the RFI and noise as the algorithm reference noise. To perform the noise and interference cancelation, the weighting factors in auxiliary antenna data are so important, that an artifcial neural network or ANN model has been used to increase the SNIR. In this research, sodium nitrite has been used as a sample, then algorithms have been tested in a nonshielded environment. The resonant frequency of the 200 g sample, by the signal-to-noise ratio improvement of 18.889 dB, the signal-to-interference ratio improvement of 24.819 dB, and the FID signal amplifcation of 16.925 dB, were measured at 4.649 MHz. The main technique in this study was to use an auxiliary antenna to estimate the noise and interference and compute the learned weighting factor before sending the NQR pulse.

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