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Evaluation of dose distribution from 12C ion in radiation therapy by FLUKA code
Jamshid Soltani-Nabipour,Abdollah Khorshidi,Faezeh Shojai,Khazar Khorami 한국원자력학회 2020 Nuclear Engineering and Technology Vol.52 No.10
Heavy ions have a high potential for destroying deep tumors that carry the highest dose at the peak of Bragg. The peak caused by a single-energy carbon beam is too narrow, which requires special measures for improvement. Here, carbon-12 (12C) ion with different energies has been used as a source for calculating the dose distribution in the water phantom, soft tissue and bone by the code of Monte Carlo-based FLUKA code. By increasing the energy of the initial beam, the amount of absorbed dose at Bragg peak in all three targets decreased, but the trend for this reduction was less severe in bone. While the maximum absorbed dose per bone-mass unit in energy of 200 MeV/u was about 30% less than the maximum absorbed dose per unit mass of water or soft tissue, it was merely 2.4% less than soft tissue in 400 MeV/u. The simulation result showed a good agreement with experimental data at GSI Darmstadt facility of biophysics group by 0.15 cm average accuracy in Bragg peak positioning. From 200 to 400 MeV/u incident energy, the Bragg peak location increased about 18 cm in soft tissue. Correspondingly, the bone and soft tissue revealed a reduction dose ratio by 2.9 and 1.9. Induced neutrons did not contribute more than 1.8% to the total energy deposited in the water phantom. Also during 12C ion bombardment, secondary fragments showed 76% and 24% of primary 200 and 400 MeV/u, respectively, were present at the Bragg-peak position. The combined treatment of carbon ions with neutron or electron beams may be more effective in local dose delivery and also treating malignant tumors.
Lung tumor segmentation using improved region growing algorithm
Jamshid Soltani-Nabipour,Abdollah Khorshidi,Behrooz Noorian 한국원자력학회 2020 Nuclear Engineering and Technology Vol.52 No.10
The goal of this project is to achieve an accurate segmentation of the pulmonary tumors besides shortening the time and increasing the accuracy. Here, improved region growing (IRG) algorithm is introduced in order to segment the lung tumor with a sufficient accuracy in a shorter time compared to the other basics methods. This comprehensive algorithm was applied on 4 patients CT images and the results of the various steps on segmentation improvement shown 98% accuracy as compared to the basic algorithm. The combination of “multipoint growth start” produced a desirable outcome in accurately bounding the tumor. The proposed algorithm improved tumor identification by less than 13% along with a sufficient percentage of compliance accuracy.
Jamshid Esmaeili,Neyram Ahooghalandary 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.23 No.3
Precast reinforced concrete structure (PRCS) consists of prefabricated members assembled at worksites and has more connections limitations in comparison with the equivalent in-situ reinforced concrete structure (IRCS). As a result of these limitations, PRCSs have less ductility in comparison with IRCSs. Recent studies indicate that the most noticeable failure in PRCSs have occurred in their connection zone. The objective of this study is introducing a type of precast beam-to-column connection (PBC) which in spite of being simple is of the same efficiency and performance as in-situ beam-to-column connection (IBC). To achieve this, the performance of proposed new PBC at exterior joint of a four story PRCS was analyzed by pseudo dynamic analysis and compared with that of IBC in equivalent IRCS. Results indicated that the proposed connection has even better performance in terms of strength, energy dissipation and stiffness, than that of IBC.
Jamshid Sangirov,Ikechi Augustine Ukaegbu,Tae-Woo Lee,Mu Hee Cho,박효훈 한국전자통신연구원 2012 ETRI Journal Vol.34 No.1
A video signal through a high-density optical link has been demonstrated to show the reliability of optical link for high- data-rate transmission. To reduce optical point-to-point links, an electrical link has been utilized for control and clock signaling. The latency and flicker with background noise occurred during the transferring of data across the optical link due to electrical-to-optical with optical-to-electrical conversions. The proposed synchronization technology combined with a flicker and denoising algorithm has given good results and can be applied in high-definition serial data interface (HD-SDI), ultra-HD-SDI, and HD multimedia interface transmission system applications.
Compressive quasistatic and dynamic behavior of SiC/ZrO2 aluminum-based nanocomposite
Jamshid Nemati,Meysam Toosian,Seyed Shahin Banisdar,Seyed Mahdi Ahmadpour 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.8
This research investigated the mechanical properties of aluminum-based nanocomposite. The spark plasma sintering method was adopted to fabricate the samples. The nanoparticles and the base metal powder were mechanically mixed in four volumetric ratios under an argon-gas-neutral atmosphere using a planetary ball milling machine. The dynamic and static compressive behaviors of the samples were studied under three different loading rates, and the microhardness of the specimens was measured. Results revealed significant improvements in microhardness, quasistatic, and the dynamic compressive strength, which can be attributed to several mechanisms, including the load transfer effect, Hall-Patch strengthening, Orowan strengthening, coefficient of thermal expansion, and elastic modulus mismatch effects. The most effective mixture was found to be 92 vol% of Al, 4 vol% of SiC, and 4 vol% of ZrO 2 . This combination of raw materials led to ultimate strengths of 204.517, 396.825, and 572.624 MPa at strain rates of 0.33, 13.33, and 2000 s -1 , respectively.
10 Gbps Transimpedance Amplifier-Receiver for Optical Interconnects
Jamshid Sangirov,이태우,박효훈,Ikechi Augustine Ukaegbu,조무희 한국광학회 2013 Current Optics and Photonics Vol.17 No.1
A transimpedance amplifier (TIA)-optical receiver (Rx) using two intersecting active feedback system with regulated-cascode (RGC) input stage has been designed and implemented for optical interconnects. The optical TIA-Rx chip is designed in a 0.13 μm CMOS technology and works up to 10 Gbps data rate. The TIA-Rx chip core occupies an area of 0.051 mm2 with power consumption of 16.9 mW at 1.3V. The measured input-referred noise of optical TIA-Rx is 20 pA/√Hz with a 3-dB bandwidth of 6.9 GHz. The proposed TIA-Rx achieved a high gain-bandwidth product per DC power figure of merit of 408 GHzΩ/mW.