• 한국태양에너지학회:학술대회논문집
• /
• 2009.04a
• /
• pp.8-12
• /
• 2009

The Knowledge of the solar radiation components are essential for modeling many solar energy systems. This is particularly the case for applications that concentrate the incident energy to attain high thermodynamic efficiency achievable only at the higher temperatures. In order to estimate the performance of concentrating thermal systems, it is necessary to know the intensity of the beam radiation, as only this component can be concentrated. The Korea Institute of Energy Research(KIER) has began collecting solar radiation component data since August, 2002. KIER's component data will be extensively used by concentrating system users or designers as well as by research institutes. The Result of analysis shows that the annual-average daily diffuse radiation on the horizontal surface is $1,458cal/m^2$ and daily direct radiation on the horizontal surface is $1,632cal/m^2$ for all over the 16 areas in Korea.

• Radiation Oncology Journal
• /
• v.2 no.2
• /
• pp.303-309
• /
• 1984

Radiation therapy(RT) has been used in the treatment of breast cancer for over 80years. Technically, it should include a part or all of such areas as chest wall or breast, axilla, internal mammary nodes (IM) and supraclavicular nodes (SCL). Authors tried three-field technique for the treatment of breast cancer using 6-MV linear accelerator, exclusively the department of radiology. Kang-Nam St. Mary's Hospital, at Catholic Medical College. The field junction was checked by a Phantom study and radiation doses measured by film densitometry and TLD. The 3 fields we used in this study were two isocentric opposing tangential fields encompassing the breast, chest wall and occasionally IM and one single anterior field encompassing the axilla and SCL. sing appropriate beam blocks and boluses, we were able to avoid unwanted intrinsic divergency of photon beam. Blocking also enabled us to set-up precise radiation field with ease.

• Journal of the Korean Society for Heat Treatment
• /
• v.23 no.4
• /
• pp.205-209
• /
• 2010

Transparent and conductive AZO films were deposited on the glass by using radio frequency (RF) magnetron sputtering with intense electron radiation, simultaneously. After deposition, the effect of electron radiation energy on the optical and electrical properties of AZO was investigated. In XRD measurements, the films irradiated with intense electron beam show the larger grain size than that of the films prepared without electron radiation. Sheet resistance was also dependent on the electron radiation energy, while the optical transmittance in visible wavelength region was not affected seriously by electron radiation. X-.ray diffraction, UV-Vis spectrophotometer and four point probes were used to observe the crystallization, optical transmittance and sheet resistance, respectively.

• Progress in Medical Physics
• /
• v.24 no.4
• /
• pp.205-212
• /
• 2013

Recent developments of image guided radiation therapy (IGRT), especially the On Board Imaging (OBI) system and the cone beam CT (CBCT), enable the radiation treatment more accurate and reliable. IGRT is widely used in the radiation therapy as a standard of care. Use of IGRT is even expected to increase in the near future. IGRT is only beneficial to patients when it is used with proper considerations of safety and appropriateness of the techniques. Institutional procedure should be developed based on the clinical need and the deep understanding of the system before applying the new technique to the clinic. Comprehensive QA program should be established before to the clinic and imaging dose should be considered when preparing the departmental practice guidelines for IGRT.

• Journal of Korean Society on Water Environment
• /
• v.20 no.3
• /
• pp.241-244
• /
• 2004

Radiation treatment with gamma-rays and electron-beams was used to remove polyvinyl alcohol(PVA), one of the main components of dyeing wastewater. PVA was effectively decomposed by radiation treatment, thus the removal was near 100 % at an initial PVA concentration of 44 mg/L. However, total organic carbon(TOC) removal was less than 5 % due to lower transformation of PVA to $CO_2$. This directly indicates the radiation treatment alone is not appropriate for the complete decomposition of PVA. In this sense, the improvement of biodegradability($BOD_5/COD$) of PVA by radiation treatment was studied. Both gamma-ray and electron-beam treatments significantly increased the biodegradability of PVA by transforming non-biodegradable PVA to biodegradable by-products. This suggests radiation treatment, especially electron-beam treatment that showed better improvement of biodegradability, can be used as a pre-treatment of biological degradation process of PVA.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.39 no.4
• /
• pp.209-215
• /
• 2002

This paper describes beam-tilting characteristics of horizontally polarized EMCD (electromagnetically coupled dipole) array antennas. The result of one element radiator is used for array elements designs and is evaluated its characteristics. Theoretical frequency characteristics and radiation pattern of the horizontally polarized EMCD array antennas analyzed by FDTD method agree well with the measured results of the practically fabricated way antennas. The measured main beam tilt ang1e and 3 dB beam width of the fabricated 20-element array antennas are 47$^{\circ}$and about $\pm$7.5$^{\circ}$, respectively. A good radiation pattern and beam tilting characteristics are observed in experiments.

• Journal of Electrochemical Science and Technology
• /
• v.6 no.3
• /
• pp.75-80
• /
• 2015

We introduce a new synthesis method to prepare small TiO₂ nanoparticles with a narrow particle size distribution, which is achieved by electron beam (E-beam) irradiation. The effects of E-beam irradiation on the synthesis of TiO₂ nanoparticles and the electrochemical performance of TiO₂ nanoparticles as alternative anode materials for Li-ion batteries are investigated. The TiO₂ nanoparticles induced by E-beam irradiation present better cycling performance and rate capability than the TiO₂ nanoparticles synthesized by normal hydrolysis reaction. The better electrochemical performance is attributed to small particle size and narrow particle size distribution, resulting in the large surface area that provides innumerable reaction sites and short diffusion length for Li⁺ through TiO₂ nanoparticles.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2004.11a
• /
• pp.29-32
• /
• 2004

In this study, we had modelled Siemens type MLC using BEAM Monte Carlo code and tested the feasibility of the modelling. To model the Primus linac MLC, we had measured the actual dimensions of MLC and each leaves, then approximated the leaf shape. VARMLC component module was used for the modelling and leakage, tongue-and-groove effect were also considered. Simulation result showed the good agreement with the film measurement.

• Journal of the Korea Safety Management & Science
• /
• v.17 no.1
• /
• pp.119-124
• /
• 2015

According as radiation therapy technique develops, standardization of radiation therapy has been complicated by the plan QA(Quality Assurance). However, plan QA tools are two type, OADT (opposite accumulation dose tool) and 3DADT (3 dimensional accumulation dose tool). OADT is not applied to evaluation of beam path. Therefore tolerance error of beam path will establish measurement value at OADT. Plan is six beam path, five irradiation field at each beam path. And beam path error is 0 degree, 0.2 degree, 0.4 degree, 0.6 degree, 0.6 degree, 0.8 degree. Plan QA accomplishes at OADT, 3DADT. The more path error increases, the more plan QA error increases. Tolerance error of OADT path is 0.357 using tolerance error of conventional plan QA. Henceforth plan QA using OADT will include beam path error. In addition, It will increase reliability through precise and various plan technique.

• Journal of Radiation Industry
• /
• v.9 no.1
• /
• pp.15-20
• /
• 2015

Carbon fiber has received much attention owing to its properties, including a large surface-to-volume ratio, chemical and thermal stability, high thermal and electrical conductivity, and high mechanical strengths. In particular, magnetic nanopowder dispersed carbon fiber has been attractive in technological applications such as the electrochemical capacitor and electromagnetic wave shielding. In this study, the nickel-oxide-nanoparticle dispersed polyacrylonitrile (PAN) fibers were prepared through an electrospinning method. Electron beam irradiation was carried out with a 2.5 MeV beam energy to stabilize the materials. The samples were then heat-treated for stabilization and carbonization. The nanofiber surface was analyzed using a field emission scanning electron microscope (FE-SEM). The crystal structures of the carbon matrix and nickel nanopowders were analysed using X-ray diffraction (XRD). In addition, the magnetic and electrical properties were analyzed using a vibrating sample magnetometer (VSM) and 4 point probe. As the irradiation dose increases, the density of the carbon fiber was increased. In addition, the electrical properties of the carbon fiber improved through electron beam irradiation. This is because the amorphous region of the carbon fiber decreases. This electron beam effect of PAN fibers containing nickel nanoparticles confirmed their potential as a high performance carbon material for various applications.