• Journal of Radiation Protection and Research
• /
• v.10 no.2
• /
• pp.130-136
• /
• 1985

The activity measurement of a solution of $^{133}Ba$ which is an electron capture nuclide was carried out by the ${\beta}-{\gamma}$ coincidence method. The counting rates at the ${\beta}-,\;{\gamma}-$, and coincidence-channels were measured using a $4{\pi}$ proportional counter and two NaI(Tl) scintillation detectors. The specific activity of the solution calculated by the efficiency extrapolation was $(1151.01{\pm}2.99)kBqg^{-1}$ at the reference time(00h UT, 03-15-84). According to an international comparison of activity measurements organized by the Bureau International des Poids et Mesures, this result showed the difference of 0.94% to the mean value derived from the comparison.

• Proceedings of the KIEE Conference
• /
• 2003.11c
• /
• pp.612-615
• /
• 2003

In this paper, a design of radiation detector for gamma column scanner is introduced. Distillation column is important unit in Petro-chemical industries, and its on-line diagnose is very important. To get density profile measured by the radiation transmitted through column is well method for on-line diagnose as gamma scanning. For this purpose radiation detection circuit, radiation source and mechanical system for moving source and detector are required. Conventional radiation detection circuit for this application is sensitive to electric noise because of interface between the radiation circuit and the controller for mechanical system. The radiation detection system introduced here is using loop coil instead of slip ring to remove contact noise. Radiation detection system designed here for gamma scanning consist of BGO detector, high voltage circuit, PHA circuit and FSK modem. The BGO detector is used as radiation sensor, high voltage circuit and peak height analysis circuit is essential to process the signal generated from BGO detector. Micro controller convert measured data into ASCII data. FSK modem transmit ASCII data. Transmitted ASCH data is picked up in antenna coil and processed for combined function with mechanical system. This method gives good result by isolating the controlling circuit of mechanical system from radiation detecting circuit which is sensitive to noise.

• Radiation Oncology Journal
• /
• v.7 no.2
• /
• pp.293-297
• /
• 1989

Electron contamination due to the interaction between radiation beam and material was analyzed for the factors such as source-skin distance (SSD), field size, tray characteristics and position of filter, which can affect the surface dose in Cobalt teletherapy. Surface dose in open beam was more influenced by SSD with increasing field size. Relative surface charge (RSC) increased with the use of tray (solid, circular hole, slotted), compared with open beam, which is thought to be due to increased electron contamination of the tray. To reduce the surface dose, 0.4mm thick Lipowitz metal filter was used. Compared with open beam, RSC decreased by 8.8%, 11.3%, 13.3%, 16.6%, 19.3% and 21.7% for the field size of $5{\times}5$, $10{\times}10$, $15{\times}15$, $20{\times}20$, $25{\times}25$ and $30{\times}30cm^2$, respectively. On the contrary, use of Lipowitz metal filter increased RSC at 60cm or less SSD. Surface dose was effectively reduced with Lpowitz metal filter placed right below solid tray in Cobalt teletherapy.

• Korean Journal of Food Science and Technology
• /
• v.4 no.2
• /
• pp.95-99
• /
• 1972

Studies were made to investigate the influence of vacuum packing after irradiating mean doses of gamma ray at freezing temperature $(-20^{\circ}C)$ on the keeping quality and color of raw beef. Fresh round steaks were packaged anaerobically in aluminum foil, and irradiated with 0.25 and 0.5 Mrad followed by storage at $5^{\circ}C$. The shelf life of beef irradiated with 0.5 Mrad could be extended about 10 days longer than unirradiated, and the off-odors was not developed. The discoloration by irradiation was shown, but soon reverted to about 90 percentage myoglobin in 20 hours.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2013.05a
• /
• pp.311-314
• /
• 2013

본 논문에서는 일본의 (주) 동경전력이 공개한 후쿠시마 제 1 원자력발전소 2 호기 원자로건물 지하에 위치한 S/C (Suppression Chamber) 주변의 Vent 관 조사 동영상들을 분석하였다. S/C 는 donut (환형) 모양의 구조물로 PCV (격납용기) 와 연결된 8 개의 Vent 관을 통해 원자로의 압력을 억제한다. 후쿠시마 사고 원자로의 용융 핵연료를 인출하기 위해서는 원자로 압력용기 및 PCV에 물을 채워서 방사선 선량율을 떨어뜨려야 한다. 물을 채운 후에 누설이 되면 안되기 때문에, PCV 와 S/C 사이에 연결된 Vent 관에 대한 방사능 오염수의 누설지점을 찾는 것이 중요하다. 이를 위한 사전공정으로 (주) 도시바의 4 족보행 로봇 탑재 카메라를 이용하여 8 개 Vent 관 모두를 육안 검사하였다. (주) 동경전력이 공개한 영상을 분석한 결과 고선량 감마선에 의한 Speckle 들이 관측되었다. 본 논문에서는 이러한 Speckle 분포의 특성을 분석하여 S/C 와 PCV 를 연결하는 8개 Vent 관중 방사능 오염물질이 많은 곳을 특정하고자 하였다.

• Progress in Medical Physics
• /
• v.25 no.1
• /
• pp.31-36
• /
• 2014

We aimed to evaluate the dosimetric characteristics of reproducibility, linearity and dose dependence of optical stimulated luminance dosimeter (OSLD) in the Co-60 Gamma-rays and to analyze with a precedent study in field of the diagnostic radiography and radiotherapy. The reproducibility was 0.76% of the coefficient of variation, the homogeneity was within 1.5% of the coefficient of variation and OSLD had supra-linear response more than 3 Gy. So the correlation between dose and count was fitted by quadratic function. The count depletion by repeated reading was 0.04% per reading regardless of the irradiated dose. And the half time of decay curve according to the irradiated dose was 0.68 min. with 1 Gy, 1.04 min. with 5 Gy, and 1.10 min. with 10 Gy, respectively. In case of annealing for 30 min, the removal rate was 88% with 1 Gy, 90% with 5 Gy, and 92% with 10 Gy, respectively and 99% in case of annealing time for 4 hour. It is feasible to use OSLDs for dose evaluation in Co-60 Gamma-rays when considering the uncertainty on the procedure according to the irradiated dose.

• Journal of the Korean Society of Radiology
• /
• v.12 no.1
• /
• pp.9-16
• /
• 2018

Hangover after drinking is different from person to person symptoms and degree, but usually thirst, fatigue, headache, general boredom, gastrointestinal disorder, vomiting, diarrhea, deficiency of vitamin appears. This hanging phenomenon is caused by the action of precursors such as ethyl acetate and acetaldehyde, which are the by products of fermentation contained in alcohol and alcohol accumulated in hepatocytes and body. In order to solve the hangover phenomenon, the same Origin as polysaccharide Polydeoxyribonucleotide, which is a nucleic acid-sugar-phosphate complex, which is a semen or testicular extract in salmon extract, and a water soluble salmon extract powder having the same structure and lower price than Polydeoxyribonucleotide And D-Glucuronic acid and N-Acetyl glucosamine. It has excellent biocompatibility, viscoelasticity and moisturizing power. It has effect on reduction of body water loss and skin moisture content in hangover phenomenon. It is antioxidant and skin moisturizing effect Hyaluronic acid was irradiated with gamma rays, and the composition was prepared by using the salmon extract powder and the main raw material. The ethanol degradation, the acetaldehyde reduction amount, the blood acetaldehyde concentration and the acetic acid concentration were measured to evaluate the alcoholysis effect, Skin moisture evaporation rate To examine the evaluation unit water content of the skin was improved determine whether the antioxidant and provide skin moisturizing effect. The addition of ethanol extracts of salmon extracts showed a decrease of 5 to 7 times compared with no addition, and a decrease of 3 to 5 times of acetaldehyde. In addition, the change of acetaldehyde concentration and acetic acid concentration in blood showed a rapid decrease compared to the no - added control group. In addition, when the raw material of hyaluronic acid was used, skin moisture content was high and skin moisture evaporation amount was decreased. Therefore, hyaluronic acid, which is a polysaccharide polymer, has excellent viscoelasticity and moisturizing ability, It is considered to provide antioxidant and skin moisturizing effect. Therefore, it can be said that the composition containing salmon extract powder and hyaluronic acid as a main ingredient is effective for the hangover phenomenon which occurs after drinking.

• Journal of radiological science and technology
• /
• v.39 no.2
• /
• pp.237-246
• /
• 2016

This study is therefore aimed at measuring the surface dose rate and the spatial dose rate in and outside the radionuclide facility in order to ensure safety of the patients, radiation workers and family care-givers in their use of such equipment and to provide a basic framework for further research on radiation protection. The study was conducted at 4 restrooms in and outside the radionuclide facility of a general hospital in Incheon between May 1 and July 31, 2014. During the study period, the spatial contamination dose rate and the surface contamination dose rate before and after radiation use were measured at the 4 places-thyroid therapy room, PET center, gamma camera room, and outpatient department. According to the restroom use survey by hospitals, restrooms in the radionuclide facility were used not only by patients but also by family care-givers and some of radiation workers. The highest cumulative spatial radiation dose rate was 8.86 mSv/hr at camera room restroom, followed by 7.31 mSv/hr at radioactive iodine therapy room restroom, 2.29 mSv/hr at PET center restroom, and 0.26 mSv/hr at outpatient department restroom, respectively. The surface radiation dose rate measured before and after radiation use was the highest at toilets, which are in direct contact with patient's excretion, followed by the center and the entrance of restrooms. Unsealed radioactive sources used in nuclear medicine are relatively safe due to short half lives and low energy. A patient who received those radioactive sources, however, may become a mobile radioactive source and contaminate areas the patient contacts-camera room, sedation room, and restroom-through secretion and excretion. Therefore, patients administered radionuclides should be advised to drink sufficient amounts of water to efficiently minimize radiation exposure to others by reducing the biological half-life, and members of the public-family care-givers, pregnant women, and children-be as far away from the patients until the dose remains below the permitted dose limit.

• Progress in Medical Physics
• /
• v.23 no.1
• /
• pp.33-41
• /
• 2012

For applying the quality assurance (QA) of volumetric modulated arc therapy (VMAT) introduced in Eulji Hospital, we classify it into three different QA steps, treatment planning QA, pretreatment delivering QA, and treatment verifying QA. These steps are based on the existing intensity modulated radiation therapy (IMRT) QA that is currently used in our hospital. In each QA step, the evaluated items that are from QA program are configured and documented. In this study, QA program is not only applied to actual patient treatment, but also evaluated to establish a reference of clinical acceptance in pretreatment delivering QA. As a result, the confidence limits (CLs) in the measurements for the high-dose and low-dose regions are similar to the conventional IMRT level, and the clinical acceptance references in our hospital are determined to be 3 to 5% for the high-dose and the low-dose regions, respectively. Due to the characteristics of VMAT, evaluation of the intensity map was carried out using an ArcCheck device that was able to measure the intensity map in all directions, $360^{\circ}$. With a couple of dosimetric devices, the gamma index was evaluated and analyzed. The results were similar to the result of individual intensity maps in IMRT. Mapcheck, which is a 2-dimensional (2D) array device, was used to display the isodose distributions and gave very excellent local CL results. Thus, in our hospital, the acceptance references used in practical clinical application for the intensity maps of $360^{\circ}$ directions and the coronal isodose distributions were determined to be 93% and 95%, respectively. To reduce arbitrary uncertainties and system errors, we had to evaluate the local CLs by using a phantom and to cooperate with multiple organizations to participate in this evaluation. In addition, we had to evaluate the local CLs by dividing them into different sections about the patient treatment points in practical clinics.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.6
• /
• pp.805-813
• /
• 2005

In our previous study, a novel herb mixture (HIM-I) of Angelim gigas radix, Cnidium officinale rhizoma, and Paeonia japonica radix was developed to protect the intestinal and immune systems and promote its recovery against radiation damage. In this study, a new herbal preparation (HemoHIM) with the high immune modulating activity was developed from HIM-I. HIM-I was fractionated into ethanol fraction (HIM-I-E) and polysaccharide fraction (HIM-I-P). And HemoHIM was prepared by adding HIM-I-P to HIM-I. The protective activities against $\gamma$ -irradiation were compared among HemoHIM, HIM-I and the fractions. HemoHIM and HIM-I significantly decreased the radiation-induced DNA damage in vitro, and scavenged hydroxyl radicals in a dose-dependent manner. HemoHIM showed similar activity to HIM-I. In vitro proliferation assay with mouse lymphocytes and bone marrow cells showed that HIM-I-P was remarkably higher than HIM-I and HIM-I-E in cell proliferating activity. HemoHIM showed higher activity than HIM-I and this might be associated with the higher polysaccharide content. The in vivo protective effects of HemoHIM and HIM-I were investigated in $\gamma$-irradiated mice. HemoHIM increased the surviving intestinal crypts to a similar extent compared with HIM-I. In contrast, HemoHIM appeared to be more effective than HIM-I in endogenous spleen colony formation assay. The recovery of white blood cells and lymphocytes in irradiated mice were significantly enhanced by the administration of HemoHIM. Also HemoHIM administration prolonged the survival of irradiated mice. These results showed that the novel herbal preparation, HemoHIM, effectively protected the self-renewal tissues and immune system, and promoted the survival of irradiated mice. Moreover, in comparison with HIM-I, HemoHIM maintained similar activity in the reduction of oxidative damage of self-renewal tissue but exhibited the higher activity in protection and proliferation of immune and hematopoietic cells. These results suggested that HemoHIM might be more effective than HIM-I in immune modulation as well as radioprotection.