• Journal of Radiation Industry
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• v.8 no.2
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• pp.71-76
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• 2014

Endocrine disrupting chemicals (EDCs) and potential EDCs are mostly man-made, found in various materials such as pesticides, additives or contaminants in food, and personal care products. The high energy ionizing radiation has the ability to remove the EDCs with a very high degree of reliability and in a clean and efficient manner. The ionizing radiation interacts with EDCs both directly and indirectly. Direct interaction takes place with EDCs and the structure of EDCs is destroyed or changed. During indirect interaction, radiolysis products of water result in the formation of highly reactive intermediates which then react with the target molecules, culminating in structural changes. To confirm the radiation reduction of EDCs in industrial sludge, a pilot scale experiment up to 50 kGy of electron beam (EB) was conducted with samples from the textile dyeing industries. The experimental result showed the over 90% of reduction of Nonylphenol (NP) and Di(2-ethylhexyl) phthalate (DEHP) at around 10 kGy of absorbed doses.

• Structural Engineering and Mechanics
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• v.89 no.3
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• pp.265-281
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• 2024

The sound radiation responses of multi-layer composite plates subjected to harmonic mechanical excitation in hygrothermal environment is numerically investigated. A homogenized micromechanical finite element (FE) based on the higher-order mid-plane kinematics replicating quadratic function as well as the through the thickness stretching effect together with the indirect boundary element (IBE) scheme has been first time employed. The isoparametric Lagrangian element (ten degrees of freedom per node) is used for discretization to attain the hygro-thermo-elastic natural frequencies and the modes of the plate via Hamilton's principle. The effective material properties under combined hygrothermal loading are considered via a micromechanical model. An IBE method is then implemented to attain structure-surrounding coupling and the Helmholtz wave equation is solved to compute the sound radiation responses. The effectiveness of the model is tested by converging it with the similar analytical/numerical results as well as the experimentally acquired data. The present scheme is further hold out for solving diverse numerical illustrations. The results revealed the relevance of the current higher-order FE-IBE micromechanical model in realistic estimation of hygro-thermo-acoustic responses. The geometrical parameters, volume fraction of fiber, layup, and support conditions alongside the hygrothermal load is found to have significant influence on the vibroacoustic characteristics.

• Imaging Science in Dentistry
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• v.43 no.2
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• pp.77-84
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• 2013

Purpose: This study aimed to provide comparative measurements of the effective dose from direct and indirect digital panoramic units according to phantoms and exposure parameters. Materials and Methods: Dose measurements were carried out using a head phantom representing an average man (175 cm tall, 73.5 kg male) and a limbless whole body phantom representing an average woman (155 cm tall, 50 kg female). Lithium fluoride thermoluminescent dosimeter (TLD) chips were used for the dosimeter. Two direct and 2 indirect digital panoramic units were evaluated in this study. Effective doses were derived using 2007 International Commission on Radiological Protection (ICRP) recommendations. Results: The effective doses of the 4 digital panoramic units ranged between $8.9{\mu}Sv$ and $37.8{\mu}Sv$. By using the head phantom, the effective doses from the direct digital panoramic units ($37.8{\mu}Sv$, $27.6{\mu}Sv$) were higher than those from the indirect units ($8.9{\mu}Sv$, $15.9{\mu}Sv$). The same panoramic unit showed the difference in effective doses according to the gender of the phantom, numbers and locations of TLDs, and kVp. Conclusion: To reasonably assess the radiation risk from various dental radiographic units, the effective doses should be obtained with the same numbers and locations of TLDs, and with standard hospital exposure. After that, it is necessary to survey the effective doses from various dental radiographic units according to the gender with the corresponding phantom.

• Journal of radiological science and technology
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• v.26 no.4
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• pp.11-19
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• 2003

chest Indirect radiography were taken at 44 medical facilities in Seoul area. The results were as follows: 1. The average tube voltage was 98.2 kVp in case of 100 mm film and 91.3 kVp in case of 70 mm film. 2. The average tube current was 18.1 mAs in case of 100 mm film and 42.5 mAs in case of 70 mm film. 3. In the physical evaluation of chest Indirect radiographs, the density in case of 100 mm film was similar to that in case of 70 mm film. 4. In the visual evaluation of chest Indirect radiographs, the score of identification in case of 100 mm film was higher than that in case of 70 mm film. 5. The average dose of radiation into the skin was 1.38 mGy in case of 100mm film and 4.59 mGy in case of 70 mm film. In conclusion, the image quality of chests was excellent and the dose of radiation into the skin decreased in case of 100 mm film.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.90-93
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• 2005

Power Flow Boundary Element Method(PFBEM) has been used as a promising tool for radiation problems in the midium-to-high frequency. PFBEM is the numerical method that applies boundary element technique to Power Flow Analysis (PFA). Indirect PFBEM is developed for acoustic scattering problems in the open field and in various frequency. To verify the analytic results of indirect PFBEM for acoustic scattering problems are compared with those of SYSNOISE, and the results using two analytic methods show a good agreement.

• Journal of Korean Academy of Nursing
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• v.53 no.2
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• pp.222-235
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• 2023

Purpose: The aim of this study was to identify the factors explaining protective behaviors against radiation exposure in perioperative nurses based on the theory of planned behavior. Methods: This was a cross-sectional study. A total of 229 perioperative nurses participated between October 3 and October 20, 2021. Data were analyzed using SPSS/WIN 23.0 and AMOS 23.0 software. The three exogenous variables (attitude toward radiation protective behaviors, subjective norm, and perceived behavioral control) and two endogenous variables (radiation protective intention and radiation protective behaviors) were surveyed. Results: The hypothetical model fit the data (χ²/df = 1.18, SRMR = .02, TLI = .98, CFI = .99, RMSEA = .03). Radiation protective intention (β = .24, p = .001) and attitude toward radiation protective behaviors (β = .32, p = .002) had direct effects on radiation protective behaviors. Subjective norm (β = .43, p = .002) and perceived behavior control (β = .24, p = .003) had direct effects on radiation protective intention, which explained 38.0% of the variance. Subjective norm (β = .10, p = .001) and perceived behavior control (β = .06, p = .002) had indirect effects via radiation protective intention on radiation protective behaviors. Attitude toward radiation protective behaviors, subjective norm, and perceived behavioral control were the significant factors explaining 49.0% of the variance in radiation protective behaviors. Conclusion: This study shows that the theory of planned behavior can be used to effectively predict radiation protective behaviors in perioperative nurses. Radiation safety guidelines or education programs to enhance perioperative nurses' protective behaviors should focus on radiation protective intention, attitude toward radiation protective behaviors, subjective norm, and perceived behavioral control.

• International Journal of Contents
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• v.16 no.2
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• pp.102-108
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• 2020

The purpose of this study was to estimate and analyze the potential radiation dose that the future visitors and the cleaning staff will be exposed to when the KRR-1 reactor is converted into a memorial hall. The radiation doses were estimated using the RESRAD-BUILD software, where case, building, receptor, shielding, and source parameters were applied as the input data. Also, the basic data for the assessment of the radiation doses were determined in an indirect manner using the data on the waste generated during the decommissioning process of the reactor. The assessment results indicate that the potential radiation dose to the visitors and the cleaning staff will be less than 1 mSv, the annual dose limit for the general public. However, if anyone for a significant period of time is close to the reactor, the overall dose will increase. The radiation dose for the future visitors and the cleaning staff was determined to be lower than the annual dose limit for the general public. Given such a risk, systematic measures, such as periodic monitoring or limiting hours, are imperative.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.247-253
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• 2013

The purpose is a comparative evaluation in the DR System according to the dosimetry and image quality of the quantitative and objective via Direct digital radiography, Indirect digital radiography, Image intensifier (Charge Coupled Device type) digital radiography. The experimental method used rando phantom and measured the entrance surface dose. And through using the measured entrance surface dose and then using the PCXMC program were evaluated risk due to irradiation and the effective dose. SNR and NPS and CNR were measured and analyzed by using 21cm acryl phantom. Significance of measured value was evaluated by statistics method. Entrance surface dose, major organ dose, effective dose all of them were measured the lowest rated in direct DR when it is on the basis of direct DR dose, high-dose ratio were measured in I.I DR approximately 1.3 times, indirect DR approximately 2.4 times. Risk in accordance with radiation also was measured same as dose ratio. On the conclusion that SNR measurement result based on direct DR SNR measurements, low-SNR ratio were measured in I.I DR approximately 7.25 times, indirect DR approximately 1.48 times. On the conclusion that CNR measurement result based on direct DR CNR measurements, high-dose ratio were measured in I.I type DR approximately 1.16 tims and low-dose ratio were measured in indirect DR approximately 0.87 times. Therefore Direct DR system using a-selenium sensing element to detect x-ray photon is thought effectively at the examination such as infant to sensitive irradiation and the genital gland. Because quality image is built by low dose. Also when it is necessary that image test requiring many diagnosis information, indirect DR system is thought effectively.

• Magazine of the Korean Society of Agricultural Engineers
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• v.19 no.4
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• pp.4544-4554
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• 1977

The objective of this study was to measure and compare the radiation heat load generated through a few chosen shade-materials that would protect animals from the direct solar radiation heat in summer condition. The results obtained from this study are as follows; 1. when the materials were used in original state, the most effective material for radiation heat reduction was slate, followed by aluminum and galvanized steel successively. 2. The radiation heat load under the white top and black underside aluminum was 2.5 Cal. per hour per square cm less than that under the bare aluminum of their diurnal peak. 3. When the modified galvanized steel was used, the radiation heat load was reduced as much as 2.4 cal per hour per square cm by attaching plywood under the galvanized steel, 3.9 cal per hour per square cm by attaching plywood and coating white paint on the top of the galvanized steel. The galvanized steel covered by hay material showes similar result as that of the galvanized steel lined with plywood. 4. In case of slate, the radiation heat reduction value was increased by using bare slate, white top slate and white-top-black-underside slate in the descending order. 5. The calculated value of radiosity of inside surface of aluminum was about 20 percent of the radiation heat load, the reduced value of radiosity by coating paint was considered to be indirect indication of the effect of total radiation heat load reduction of painted surface. 6. About an hour of the time lag of radiation heat load peak on sept. 10 for slate materials should be investigated more comprehensively in future.

• Korean Journal of Environmental Biology
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• v.22 no.3
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• pp.472-477
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• 2004

To study the radiation related gene expression in mutants of Bacillus lentimorbus WJ5 induced by gamm radiation, the simultaneous gene expression was analyzed by DNA micro array. We constructed DNA chips including two thousand randomly digested genome spots of B. lentimorbus WJ5 and compared its quantitative aspect with seven mutants induced by gamma radiation $(^{60}/Co)$. From the cluster analysis of gene expression pattern, totally 408 genes were expressed and 27 genes were significantly upregulated by the gamma radiation in all mutants. Especially, genes involved in repair (mutL, mutM), energy metabolism (acsA, sdhB, pgk, yhjB, citB), protease (npr), and reduction response to oxidative stress (HMM) were simultaneously upregulated. It seems that the induction of the direct and/or indirect repair related genes in mutants induced by gamma radiation could be remarkably different from the adaptive responses against acute exposure to radiation.