1.The Comparison of the KAPM Dosimetric Protocol (1990) with the TG-21 and Clambda/C(E) Method.
Byong Yong YI ; Eun Kyung CHOI ; Hyesook CHANG
Journal of the Korean Society for Therapeutic Radiology 1991;9(2):337-342
The Comparison of the KAPM Dosimetric Protocol (1990) with the TG-21 and Clambda/C(E) (ICRU-21 and SCRAD protocol) method is studied. The therapetutic range of radiation (photon 4MV-15MV and electron 6MeV-20MeV)and three kinds of the chambers were used in the water phantom. The Results from TG-21 and KAPM Protocol did not show much differences (less than 1%) throughout the whole energy range; N(D) from KAPM protocol and Ngas from TG-21 showed 0.2% deviation mainly from W/e difference between two protocols. But the results from KAPM protocol (1990) and those from Clambda/C(E) Method showed -1.9+/-0.6%(KAPM protocol is higher) deviation for photom beam and +3.3+/-1% (KAPM protocol is lower) deviation for electron beams.
Water
2.Accuracy Evaluation of Treatment Planning System Using Irregular-surface Water Phantom.
Dong Hyeok JEONG ; Ki Hwan KIM ; Kang Kyoo LEE ; Sun Rock MOON ; Jhin Kee KIM ; Kyo Chul SHIN ; Young Kee OH ; Jeung Kee KIM ; Moon June CHO ; Jun Sang KIM
Korean Journal of Medical Physics 2008;19(2):131-138
We evaluated on the calculation accuracy of treatment planning system (TPS) with phantom having convex and concave surface. The TPS is Eclipse (Varian, USA) using both algorithms AAA and PBC for photon dose calculations. PBC algorithms have three corrections of Batho, modified Batho (M-Batho), and equivalent TAR (E-TAR). The field sizes were 10x10 cm2 and 20x20 cm2, and MLC-shaped fields for these fields. We measured doses at three depths 5, 10 and 15 cm in phantom of SSD=90 cm in the condition of inserted farmer chamber. For given conditions, we have calculated dose with these algorithms and compared them with measured doses. In AAA the calculated doses (dose/MU) were agreed to measured doses within +/-1% in flat and convex surface and were under estimated with -1.9% maximum in concave surface. In PBC the calculated doses were over estimated with +1.7% and +4.1% respectively in flat and convex surface and the differences were from -3.1% to +2.1% in concave surface. In comparison of criteria from AAPM and IAEA reports, and statistical analysis for these results, it is found that the AAA's results are in good agreement with measured values and the M-Batho's results are generally good agreed with measured values among PBC algorithms.
Water
3.Characteristics of Detectors for Measurements of Photon Depth Doses in Build-Up Region.
Sei Kwon KANG ; Byung Chul CHO ; Suk Won PARK ; Do Hoon OH ; Hee Chul PARK ; Su Ssan KIM ; Hoonsik BAE
Korean Journal of Medical Physics 2005;16(2):77-81
To determine the appropriate method out of various available methods to measure build-up doses, the measurements and comparisons of depth doses of build-up region including the surface dose were executed using the Attix parallel-plate ionization chamber, the Markus chamber, a cylindrical ionization chamber, and a diode detector. Based on the measurements using the Attix chamber, discrepancies of the Markus chamber were within 2% for the open field and increased up to 3.9% in the case of photon beam containing the contaminant electrons. The measurements of an cylindrical ionization chamber and a diode detector accord with those of the Attix chamber within 1.5% and 1.0% after those detectors were completely immersed in the water phantom. The results suggest that the parallel-plate chamber is the best choice to measure depth doses in the build-up region containing the surface, however, using cylindrical ionization chamber or diode detector would be a reasonable choice if no special care is necessary for the exact surface dose.
Water
4.Hereditary Papulotranslucent Acrokeratoderma: Prominent Clinical Presentation after Water Exposure
Beom Jun KIM ; Jihee KIM ; Sang Ho OH
Annals of Dermatology 2019;31(Suppl):S52-S53
No abstract available.
Water
5.Situation of water supply and some factors of water pollution
Journal of Practical Medicine 2002;435(11):2-5
This study introduced the main water resources for daily accommodation in 3 districts of ¢n Biªn, Hßn §Êt, and T©n HiÖp, including pond and lake water (52.72%), rainy water (42.74%) and drilling well water (4.08%). Some risks of pollution of the water resources such as no filtration and polluted drainage for rainy water, sewage surrounding the drilling well and pollution resources far from the drilling well less than 10 m.
Water Pollution
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water
6.Mutagenic Activity of Organic Pollutans in Drinking Water in Seoul.
Dong Chun SHIN ; Jae Yeon JANG ; Seong Joon JO ; Yong CHUN
Korean Journal of Preventive Medicine 1988;21(2):284-294
To measure the mutagenic activity of micro-organic pollutants in drinking water, mutagenic test was conducted using Salmnella typhimurium TA 98 strain on the water sample taken from three water supply station and six tap water in Seoul in July and November 1987. The results were as follows : 1. The average amounts of organic matters in raw, treated, and tap water sampled in July were 0.38mg/l, 0.28mg/l, and 0.45mg/l, respectively, and sampled in November were 0.34mg/l, 0.24mg/l, and 0.22mg/l, respectively. The amount of organic matters of tap water sampled in November did not increase while that of tap water sampled in July increased compare to those of raw or treated water. 2. The amount of organic matters is the highest in neutral fraction compare to acidic and basic fractions. 3. In the five out of six tap water and raw water of Paldang and Kuui station sampled in July, the mutagenic ratios were greater than two (both direct and indirect mutagenicity). 4. In the three out six tap water and raw and treated water of Kuui station sampled in November, the mutagenic ratios were greater than two. 5. While mutagenic were low in acidic and basic fraction, they were high in neutral fraction. The samples which had high mutagenic activity in the total amount also showed high mutagenic activity in neutral fraction. 6. While mutagenic activity was decreased after the treatment of water, it was increased in tap water as the distance from the water supply station increases.
Drinking Water*
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Drinking*
;
Seoul*
;
Water
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Water Supply
7.Characterization and Detection of Enteric Viruses in Surface Water, Finished Water, Tap Water by Total Culturable Virus Assay (TCVA) Method.
Eun mi KO ; Seok Jea JANG ; Hee Jung KIM ; Eun suk HONG ; Yung Oh SHIN ; Sang Hyun KIM
Journal of Bacteriology and Virology 2004;34(2):137-145
The information of species and quantity of enteric viruses in surface water, finished water, and tap water is important in helping understand the pathogenesis of viruses, providing information about health and hygiene, improving handling technique of drinking water, and establishing the standards of water quality. Using standard total culturable virus assay-most probable number (TCVA-MPN) method, we tried to detect infectious enteric viruses in surface water, finished water, and tap water samples that were collected and evaluated according to the information collection rule (ICR). The results obtained with TCVA method were compared to the results from both reverse transcription-polymerase chain reaction (RT-PCR) and integrated cell culture-RT-PCR (ICC-RT-PCR) method. Five of 86 samples (5.8%) were positive as determined by the TCVA-MPN method. Two of 86 samples (2.3%) were positive for reovirus as determined by the RT-PCR and ICC-RT-PCR, and contained infectious reovirus. One of 86 samples (1.7%) was positive for coxsackievirus type B3 as determined by the RT-PCR and ICC-RT-PCR.
Drinking Water
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Hygiene
;
Water Quality
;
Water*
8.Study on Absorbed Dose Determination of Electron Beam Quality for Cross-calibration with Plane-parallel Ionization Chamber.
Jeong Eun RAH ; Dong Oh SHIN ; So Hyun PARK ; Hojin JEONG ; Ui Jung HWANG ; Sung Hwan AHN ; Young Kyung LIM ; Dong Wook KIM ; Myonggeun YOON ; Dong Ho SHIN ; Se Byeong LEE ; Tae Suk SUH ; Sung Yong PARK
Korean Journal of Medical Physics 2009;20(2):97-105
Absorbed dose to water based protocols recommended that plane-parallel chambers be calibrated against calibrated cylindrical chambers in a high energy electron beam with R50>7 g/cm2 (E> or =16 MeV). However, such high-energy electron beams are not available at all radiotherapy centers. In this study, we are compared the absorbed dose to water determined according to cross-calibration method in a high energy electron beam of 16 MeV and in electron beam energies of 12 MeV below the cross-calibration quality remark. Absorbed dose were performed for PTW 30013, Wellhofer FC65G Farmer type cylindrical chamber and for PTW 34001, Wellhofer PPC40 Roos type plane-parallel chamber. The cylindrical and the plane-parallel chamber to be calibrated are compared by alternately positioning each at reference depth, zref=0.6R50-0.1 in water phantom. The DW of plane-parallel chamber are derived using across-calibration method at high-energy electron beams of 16, 20 MeV. Then a good agreement is obtained the DW of plane-parallel chamber in 12 MeV. The agreement between 20 MeV and 12 MeV are within 0.2% for IAEA TRS-398.
Electrons
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Water
9.Disorders of Water Metabolism.
Korean Journal of Pediatrics 2004;47(Suppl 4):S761-S771
No abstract available.
Metabolism*
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Water*
10.Verification of the PMCEPT Monte Carlo dose Calculation Code for Simulations in Medical Physics.
Korean Journal of Medical Physics 2008;19(1):21-34
The parallel Monte Carlo electron and photon transport (PMCEPT) code [Kum and Lee, J. Korean Phys. Soc. 47, 716 (2006)] for calculating electron and photon beam doses has been developed based on the three dimensional geometry defined by computed tomography (CT) images and implemented on the Beowulf PC cluster. Understanding the limitations of Monte Carlo codes is useful in order to avoid systematic errors in simulations and to suggest further improvement of the codes. We evaluated the PMCEPT code by comparing its normalized depth doses for electron and photon beams with those of MCNP5, EGS4, DPM, and GEANT4 codes, and with measurements. The PMCEPT results agreed well with others in homogeneous and heterogeneous media within an error of 1~3% of the dose maximum. The computing time benchmark has also been performed for two cases, showing that the PMCEPT code was approximately twenty times faster than the MCNP5 for 20-MeV electron beams irradiated on the water phantom. For the 18-MV photon beams irradiated on the water phantom, the PMCEPT was three times faster than the GEANT4. Thus, the results suggest that the PMCEPT code is indeed appropriate for both fast and accurate simulations.
Electrons
;
Water