• Journal of Korean Society of Water and Wastewater
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• v.36 no.3
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• pp.167-175
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• 2022

The degradation of EBT (Eriochrome Black T) in an aqueous solution was investigated at various values of pH, Ferrate (VI) dosage, initial concentration, aqueous solution temperature. The maximum degradation efficiency was 95.42% at pH 7 and in that experimental condition, the kapp value was 872.87 M-1s-1. The degradation efficiency was proportional to the dosage of Ferrate (VI). Also, the initial rate constant of EBT degradation increased with decreasing of the EBT initial concentration. In addition, the degradation rate of EBT was increased from 74.04% to 95.42% when the temperature in the aqueous solution was increased from 10℃ to 45℃. The activation energy value was 11.9 kJ/mol for EBT degradation. Overall, the results of the degradation experiment showed that Ferrate (VI) could effectively oxidize the EBT in the aqueous phase.

• Journal of the Korean Chemical Society
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• v.17 no.4
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• pp.256-261
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• 1973

Complex formation of magnesium-Eriochrome Black T at constant ionic strength and hydrogen ion concentration have been studied spectrophotometrically in acetonitrile solution. The measured pH values were calibrated with standard buffer solutions by using a glass electrode Ag/0.1M $AgNO_3$ reference electrode couple. The results are as follows;$E_{glass}=716+59.1\;logA_{H+}[mv]$+(in mv. vs. Ag reference electrode for picric acid $-10^{-3}M$ tetramethylammonium picrate buffer), and $E_{glass}=1,193+59.1\;logA_{H+}[mv]$(in mv. vs. Ag reference electrode for 1,3-diphenylguanidine $-3{\times}10^{-3}M $ 1,3-diphenylguanidine perchlorate buffer). The acid dissociation exponent of ligand, $ pK_{H,EBT-}$was found to be 9.1. The conditional formation constants of $MgEBT^{-}$complex by log-ratio method were 3.97 (when m = 2) and 5.02 (when m = 1) as $log K_n$, respectively, for the reaction of $H_mEBT^{(3-m)-} + Mg^{2+} {\leftrightarrow}MgEBT^{-} + mH^{+}$. The present study showed that$MgEBT^{-}$ has the composition of 1:1 which agrees with the result of Schwarzenbach et al. in aqueous solution.

• The Korean Journal of Food & Health Convergence
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• v.4 no.1
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• pp.15-22
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• 2018

A radiation dosimeter is important to assess quality assurance (QA) of radiation therapy devices and to estimate the radiation dose in vivo dosimetry. Recently, optically stimulated luminescence detector (OSLD) is widely used in clinical filed. Therefore, the purpose of this study is to evaluate dose, energy, and angular dependence of OSLD and EBT3 film. The absorbed dose in clinical linear accelerator (Linac) beam is calibrated for dose per monitor unit (MU). Dose, energy, and angular dependence of OSLD and EBT3 film are estimated after the calibration procedure. The absorbed dose is measured at 50, 100, 150, and 200 cGy in an 6 MV X-ray beam for dose dependence. A dose of 150 cGy is delivered to OSLD and EBT3 film with 6 and 10 MV photon energies for energy dependence. For measurements of angular dependence, angular positions of gantry are $0^{\circ}{\pm}80^{\circ}$ with 6 MV at 150 cGy. The results of dose dependence is linear for OSLD and EBT3 film. For the results of energy dependence, errors were 0.39% and 0.03% for OSLD and EBT3 film, respectively. The results of dose for angular is decreased from $0^{\circ}$ to ${\pm}80^{\circ}$ for both OSLD and EBT3 film. When angle of $0^{\circ}$ is normalized to 1, and the dose is decreased to 60 and 66% at $80^{\circ}$ for OSLD and EBT3 film, respectively. Dose and energy dependence of OSLD and EBT3 film are measured within the recommendation of manufacturer. Angular dependence is increased from $0^{\circ}$ to ${\pm}80^{\circ}$ for OSLD and EBT3 film. The characteristics of OSLD and EBT3 film are similar and expected to useful for clinical field.

• Journal of Advanced Navigation Technology
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• v.27 no.1
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• pp.23-35
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• 2023

Evidence-based training (EBT) improves a pilot's competency and confidence based on the data(Evidence) from actual aircraft accidents, incidents, operations, and training for safe operation in the fast-paced and large-scale air transportation field. It is a training/assessment program that strengthens resilience for problem solving. As a way to apply this evidence-based training(EBT) to the educational system of ATO and to resolve the problems, I propose 3 improvement plans. They are evaluation criteria that apply the core competencies of EBT to the educational evaluation system, the way to improve the system for standardization of practical test examiners and instructors and also the ways to use Flight Simulation Training Devices(FSTD).

• Journal of Chest Surgery
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• v.33 no.1
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• pp.7-19
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• 2000

Background :To assess the accuracy of Electron-Beam Tomography(EBT) in following evaluation of the pulmonary vascular system after a shunt operation in the cyanotic con-genital heart disease with pulmonary stenosis or pulmonary atresia. Material and Method : Sixteen patients(M:F=11:5) who received Blalock-Taussig(n=8) bidirectional cavo-pulmonary shunt(n=10) and unifocalization (n=2) were ncluded in the study. We evaluated the patency of the shunt the morphology of intrapericardial and hilar pulmonary arteries(PA) peripheral pulmonary vascularity by background lung attenuation and the abundance of arterial & venous collateral. Angiography(n=12) and echocardiography(n=20) were used as the gold standard for the comparison of EBT results. Result: EBT was consistent with angiogram/ echo in 100% of the evaluation for the patency of the shunt and in 12(by angiogram 100%) and 19(by echo 95%) for the detection the hypoplasia stenosis or interruption of central PA In measuring of PA EBT and angiogram corrlated(r=0.91) better than EBT-echo(r=0.88) or echo-angiogram(r=0.72) Abundant systemic arterial collateral were noted in 4 and venous collateral in 3 cases. In evaluating the peripheral pulmonary vascularity the homogenous and normal-ranged lung attenuation(m=6) decreased but homo-genous attenuation(n=1) segment-by-sgment heterogeneous attenuation(n=3) homogenous but asymmetrical attenuation(n=3) segment-by-segment heterogeneous attenuation(n=3) homogenous but asymmetrical attenuation(n=3) and venous congestion(n=2) were observed nd 12 of them were compatible with the blood flow pattern revealed by cardiac catheterization. Conclusion: EBT was accurate in the integrated evaluation of the pulmonary vascular system after the shunt including the patency of the shunt operaion the morphology and dimension of the central and hilar PAs and the loco-regional pulmonary flow in the lung parenchyma. It suggests the useful information about the need of secondary shunt operation the proper timing time for total repair and the need of interventional procedure prior to total repair.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.2
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• pp.83-91
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• 2017

Objectives: The purpose of this study was to evaluate the error of the leaf position accuracy of the MLC due to the gravity effect according to the gantry angle by using picket fence test using EPID and GafChromic EBT3 film. Materials and Methods: A 5 cm solid phantom was placed on the table and the SAD was set to 100 cm. The EBT3 film was placed exactly over the solid phantom and covered a 1.5 cm solid phantom and the picket fence test was performed. The EPID was measured under the same conditions as the EBT3 film at SID 100 cm. The gantry angles were measured at $0^{\circ}$, $90^{\circ}$, $180^{\circ}$ and $270^{\circ}$ in order to evaluate the position of the MLC according to the gantry angle. For the geometric evaluation of the MLC, the leaf position accuracy of the MLC was analyzed using the analysis program. Results: In case of EPID, when the gantry angle was changed to $0^{\circ}$, $90^{\circ}$, $180^{\circ}$, $270^{\circ}$, the difference of the position errors of the leaves was 0.18 mm, 0.31 mm, 0.20 mm, 0.26 mm on the average and the maximum values of the errors were respectively 0.44 mm, 0.54 mm, 0.34 mm, 0.44 mm. In case of EBT3 film, when the gantry angle was changed to $0^{\circ}$, $90^{\circ}$, $180^{\circ}$, $270^{\circ}$, the difference of the position errors of the leaves was 0.19 mm, 0.21 mm, 0.19 mm, 0.31 mm on the average and the maximum values of the errors were respectively 0.35 mm, 0.45 mm, 0.36 mm, 0.48 mm. Conclusion: In this study, we analyzed the position error of the leaf of the MLC according to the gantry angle, and confirmed the position error of the leaf by gravity effect. As a result of comparing the leaf position accuracy using EPID and EBT3 film according to the variation of gantry angle, a larger error occurred in the error analysis method using EPID than that of EBT3 film. Therefore, in the case of IMRT based on MLC, as well as verification of accurate dosimetry should be conducted, it is considered that the quality control and verification for the precise operation of the MLC will be needed. and it is necessary to compare and verify the method of analysis.

• Journal of radiological science and technology
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• v.30 no.2
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• pp.139-145
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• 2007

Dose evaluation for small field such as stereotactic radiosurgery was performed using $Gafchromic^{(R)}$ EBT film. Every film which irradiated 6MV photon beam was scanned and obtained the optical density(OD) by flat bed scanner after 24 hours of irradiation. This study compared dose from diode in water and Gafchromic $EBT^{(R)}$ film in acrylic phantom to verify the reliability of the film, and to evaluate the SRS in clinical dose distributions from calculation and measurement in the region of virtual target in humanoid and cylindrical phantoms were compared. The Gafchromic $EBT^{(R)}$ film was found to be linear up to 9Gy. The $D_{max}$ for 6 MV was measured at 1.5 cm from the surface by both of diode and the film. As the depth is deeper, the error was measured within $2{\sim}3%$ at $10{\sim}20\;cm$ depth. Comparing between distribution from calculation and measurement, we found that there is 5% error at 90% isodose line. We found that given dose could be measured accurately by using the phantoms. It was feasible to use the Gafchromic $EBT^{(R)}$ film in quality assurance of SRS.

• Journal of KIISE:Software and Applications
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• v.31 no.3
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• pp.276-292
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• 2004

In this paper. we present methods that extract lung regions from chest EBT(electron beam tomography) images then segment the extracted lung region into lung lobes. We use histogram based thresholding and mathematical morphology for extracting lung regions. For detecting pulmonary fissures, we use edge detector and knowledge-based search method. We suggest this edge detector, which uses adaptive filter scale, to work very well for real edge and insensitive for edge by noise. Our experiments showed about 95% accuracy or higher in extracting lung regions and about 5 pixel distance error in detecting pulmonary fissures.

• The Journal of Korean Society for Radiation Therapy
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• v.19 no.1
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• pp.27-33
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• 2007

Purpose: We have performed SRS (stereotactic radiosurgery) for avm (arterry vein malformation) and brain cancer. In order to verify dose and localization of SRS, dose distributions from TPS ($X-Knife^{(R)}$ 3.0, Radionics, USA) and GafChromic $EBT^{(R)}$ film in a head phantom were compared. Materials and Methods: In this study, head and neck region of conventional humanoid phantom was modified by substituting one of 2.5 cm slap with five 0.5 cm acrylic plates to stack the GafChromic $EBT^{(R)}$ film slice by slice with 5 mm intervals. Four films and five acrylic plates were cut along the contour of head phantom in axial plane. The head phantom was fixed with SRS head ring and adapted SRS localizer as same as real SRS procedure. CT images of the head phantom were acquired in 5 mm slice intervals as film interval. Five arc 6 MV photon beams using the SRS cone with 2 cm diameter were delivered 300 cGy to the target in the phantom. Ten small pieces of the film were exposed to 0, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 cGy, respectively to calibrate the GafChromic $EBT^{(R)}$ film. The films in the phantom were digitized after 24 hours and its linearity was calibrated. The pixel values of the film were converted to the dose and compared with the dose distribution from the TPS calculation. Results: Calibration curve for the GafChromic $EBT^{(R)}$ film was linear up to 900 cGy. The R2 value was better than 0.992. Discrepancy between calculated from $X-Knife^{(R)}$ 3.0 and measured dose distributions with the film was less than 5% through all slices. Conclusion: It was possible to evaluate every slice of humanoid phantom by stacking the GafChromic EBT film which is suitable for 2 dimensional dosimetry, It was found that film dosimetry using the GafChromic $EBT^{(R)}$ film is feasible for routine dosimetric QA of stereotactic radiosurgery.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3811-3815
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• 2022

Ni-63 is pure beta source which emits low energy beta particles. The Ni-63 sources were fabricated to develop the beta-voltaic battery which converts decay energy into electrical energy for power generation. Activity distribution of the source was important factor of power producibility of the beta-voltaic battery. Liquid scintillation counter widely used for measurement of low energy beta emitters was not suitable to measure activity distribution. In this study, we used the peeled-off Gafchromic™ EBT3 film to measure the activity distribution of the Ni-63 source. Absorbed dose was increased proportionally to the source activity and exposure duration. The low energy beta particles could transport the energy into the active layer without the polyester protective layer. Also, Activity distribution was measured by using the peeled-off EBT3 film. Two-dimensional dosimetric distribution was suitable to measure the activity distribution. To use the peeled-off EBT3 film is user-friendly and cost-effective method for quality assurance of the Ni-63 sources for the beta-voltaic battery.