• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.5
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• pp.483-489
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• 2002

The computer simulation has been done for non-insulated and insulated pipes which are vacant or half filled with liquid. The simulation results showed that the density profile on the radiography is continuous and symmetrical around the center of pipe in the case of vacant pipe. On the other hand the density profiles are not symmetrical and depend on geometrical setting for radiography in the case of half filled pipes. Finally, experimental testing on a non-insulated carbon steel pipe with artificial notches of different depth is carried out using Ir-192 and industrial film. Comparing the measured density profile on the radiograph to the calculated one, it has been shown that it is possible to evaluate thickness variation by measuring density profile on a radiograph.

• Journal of the Korean Society of Radiology
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• v.12 no.2
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• pp.167-172
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• 2018

This study evaluated absorbed dose of brachytherapy according to the nanoparticle in prostate cancer which many occurred in Korean man and provided basic data. Absorbed dose evaluation was using MCNPX program which was applied Monte Carlo simulation. Source was applied $^{192}Ir$ which was many using in Korean HDR machine and gold, ferric oxide, gadolinium and iodine nanoparticle were applied. Prostate absorbed dose result was increased when using nanoparticle, in particular gold nanoparticle was the highest result as $3.13E-03J/kg{\cdot}e$. Absorbed dose of surrounding organs and distance was similar between using nanoparticle and non-using nanoparticle. Therefore, brachytherapy was used nanoparticle was increased therapeutic ratio and efficiency of radiation therapy.

• Journal of Radiation Protection and Research
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• v.26 no.1
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• pp.35-43
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• 2001

All of sealing capsules to transport a special form radioactive material should be designed and fabricated in accordance with the design criteria prescribed in IAEA standards and domestic regulations. The objective of this study is to demonstrate the safety of a shipping capsule for $^{192}Ir$ special form radioisotope which produced in the HANARO. The safety tests were carried out for the impact, percussion, bending and heat test conditions. And leakage tests were carried out before and after the each test. Also, the safety analyses wert performed using computer codes in order to verify the test results. The capsule showed slight scratches and deformation, and maintained its structural and thermal integrities in all tests without any severe damage or melting. It also met the allowable limits of leakage rate after each test. Therefore, it has been verified that the capsule was designed and fabricated to meet all requirements for the special form.

• Radiation Oncology Journal
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• v.9 no.2
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• pp.227-232
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• 1991

Authors described the remote afterloading endobronchial brachytherapy (EBBT technique using the microSelectron HDR Ir-192 and the Asan Medical Center experience. Total 28 EBBT in 9 patients were performed since November 1989 and 24 EBBT in 8 patients were emploiyed for palliation and 3 EBBT in 1 patient was treated curatively. Authors observed a significant relief of obstructive symptom with tumor regression in 7 patients out of 8 who were treated palliatively but one of them died of pulmonary congestion in 3 weeks after EBBT One patient with prior therapy of extensive electrocautery expired within 1 day after 2nd EBBT procedure with massive hemorrhage from the lesion. EBBT procedure has been tolerable and can be performed as an outpatient.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.565-572
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• 2019

In this study, shielding analysis of material and thickness of 3D printer filaments was performed for the manufacture of custom shielding by radiation workers during outdoor radiographic test. The shielding was attached to the ICRU Slab Phantom after selecting the voxel source $^{192}Ir$ and $^{75}Se$ through simulation using MCNPX, and the distance between the source and the slab Phantom was set at 100 cm. The 12 shielding materials were divided into 5 mm units up to 200 mm from the absence of shielding materials to evaluate the energy absorbed per unit mass of each shielding material. The results showed that the shielding effect was high in the order of ABS + Tungsten, ABS + Bismuth, PLA + Copper, PLA + Iron from all sources of radiographic test. However, compared to lead, the shielding effect was somewhat lower. Based on this study in the future, further study of the atomic number and the high density filament material is necessary.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2599-2605
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• 2022

The Korea Retrospective Dosimetry network (KREDOS) performed an inter-laboratory comparison to confirm the harmonization and reliability of the results of retrospective dosimetry using mobile phone. The mobile phones were exposed to ¹⁹²Ir while attached to the human phantoms in the field experiment, and the exposure doses read by each laboratory were compared. This paper describes the reference dosimetry performed to present the reference values for inter-comparison and to obtain additional information about the dose distribution. Reference dosimetry included both measurement using LiF:Mg,Cu,Si and calculation via MCNP simulation to allow a comparison of doses obtained with the two different methodologies. When irradiating the phones, LiF elements were attached to the phones and phantoms and irradiated at the same time. The comparison results for the front of the phantoms were in good agreement, with an average relative difference of about 10%, while an average of about 16% relative difference occurred for the back and side of the phantom. The differences were attributed to the different characteristics of the physical and simulated phantoms, such as anatomical structure and constituent materials. Nevertheless, there was about 4% of under-estimation compared to measurements in the overall linear fitting, indicating the calculations were well matched to the measurements.

• Journal of Radiation Protection and Research
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• v.47 no.2
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• pp.93-98
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• 2022

Background: This study aims to derive the characteristics of each work type for industrial radiography based on empirical evidence through expert advice and a survey of radiation workers of various types of industrial radiography. Materials and Methods: According to a Korean report, work types of industrial radiography are classified into indoor tests, underground pipe tests, tests in a shielded room (radiographic testing [RT] room test), outdoor field tests, and outdoor large structure tests. For each work type, exposure geometry and radiation sources were mainly identified through the expert advice and workers' survey as reliable empirical evidence. Results and Discussion: The expert advice and survey results were consistent as the proportion of the work types were high in the order of RT room test, outdoor large structure test, underground pipe test, outdoor field test, and indoor test. The outdoor large structure test is the highest exposure risk work type in the industrial radiography. In most types of industrial radiography, radiation workers generally used ¹⁹²Ir as the main source. In the results of the survey, the portion of sources was high in the order of ¹⁹²Ir, X-ray generator, ⁶⁰Co, and ⁷⁵Se. As the exposure geometry, the antero-posterior geometry is dominant, and the rotational and isotropic geometry should be also considered with the work type. Conclusion: In this study, through expert advice and a survey, the external exposure characteristics for each work type of industrial radiography workers were derived. This information will be used in the reconstruction of organ dose for health effects assessment of Korean radiation workers.

• The Research Journal of the Costume Culture
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• v.31 no.1
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• pp.107-123
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• 2023

This research studied the electrical characteristics, IR transmission characteristics, stealth functions, and thermal characteristics of infrared thermal-imaging cameras of copper-sputtered samples. Nylon samples were prepared for each density as a base material for copper-sputtering treatment. Copper-sputtered NFi, NM1, NM2, NM3, NM4, and NM5, showed electrical resistance of 0.8, 445.7, 80.7, 29.7, 0.3, and 2.2 Ω, respectively, all of which are very low values; for the mesh sample, the lower the density, the lower the electrical resistance. Measuring the IR transmittance showed that the infrared transmittance of the copper-sputtered samples was significantly reduced compared to the untreated sample. Compared to the untreated samples, the transmittance went from 92.0-64.1%. When copper sputtered surface was directed to the IR irradiator, the IR transmittance went from 73.5 to 43.8%. As the density of the sample increased, the transmittance tended to decreased. After the infrared thermal imaging, the absolute values of △R, △G, and △B of the copper phase increased from 2 to 167, 98 to 192, and 7 to 118, respectively, and the closer the density of the sample (NM5→NFi), the larger the absolute value. This proves that the dense copper phase-up sample has a stealth effect on the infrared thermal imaging camera. It is believed that the copper-sputtered nylon samples produced in this study have applications in multifunctional uniforms, bio-signal detection sensors, stage costumes, etc.

• Journal of the Korean Magnetics Society
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• v.13 no.5
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• pp.187-192
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• 2003

The magnetic and thermal properties of NiFe/[IrMn-Mn]/CoFe with Mn additions have been studied. As-deposited CoFe pinned layers with [IrMn-Mn]layer had dominantly larger exchange biasing field ( $H_{ex}$) and blocking temperature ( $T_{b}$) than those with pure I $r_{22}$M $n_{78}$ used. The $H_{ex}$ and $T_{b}$ improved with 76.8-78.1 vol% Mn, but those of the NiFe/IrMn/CoFe dropped considerably with more addition of 0.6 vol % Mn. The average x-ray diffraction peak ratios of fcc [(111)CoFe, NiFe]/(111)IrM $n_3$ textures for the Mn inserted total vol of 75.5, 77.5, and 79.3% were about 1.4, 0.8, and 0.6, respectively. For the sample without Mn inserted layer, the $H_{ex}$ between IrMn and CoFe layers was almost zero, but it increased to 100 Oe after annealing of 250 $^{\circ}C$. For as-grown two multilayers samples with ultra-thin Mn layers of 77.5 and 78.7 vol %, the $H_{ex}$s were 259 and 150 Oe, respectively. In case of IrMn with 77.5 vol% Mn, the $H_{ex}$ was increased up to 475 Oe at 350 $^{\circ}C$ but decreased to 200 Oe at 450 $^{\circ}C$, respectively. The magnetic properties and thermal stabilities of NiFe/[IrMn-Mn]/CoFe multilayer were enhanced with Mn additions. In applications where higher $H_{ex}$ and $T_{b}$ are required, proper contents of Mn can be used. be used. used.

• Journal of the Korean Chemical Society
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• v.19 no.5
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• pp.343-350
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• 1975

About 20${\sim}$100${\mu}g$ iridium have been extracted quantitatively as stannous-chloro Complex from aqueous solution by Alamine-336, a high molecular weight tertiary amine, dissolved in benzene. The extractability was confirmed by radioactive tracer of iridium-192. The spectrophotometric measurements of the extracted species at 322.5 nm indicate the feasibility of this method to be used as an analytical procedure for the determination of micro amount of iridium. An anion model of stannous-chloro complex of iridium has been postulated to account for the extraction mechanism.