• 한국육종학회지
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• 제40권2호
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• pp.113-118
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• 2008

This study was carried out to investigate the chemical composition of peanut mutants induced by gamma radiation (Co-60) at 300 Gy in seeds of the cultivar Shinnamkwang. The protein contents of twenty-eight peanut mutants ranged from 23.3% to 31.7% and were increased by from 0.5% to 8.4% in fifteen mutants lines from the 26.8% of the original variety, cv. Shinnamkwang. Lipid contents of in mutants ranged from 43.2% to 53.5%, an increase of 0.2% to 5.7% from the 47.8% of the original variety. The range of unsaturated oleic acid in 28 mutants was from 38.9% to 56.9% an increase of from 1.3% to 14.0% from the 50.6% in the original variety. Linoleic acid, the highest unsaturated fatty acid, constituted 32.6% meanly of mutants, it was 17.4% lesser than oleic acid, ranging from 25.9% to 42.0%. Palmitic acid (16:0) contents ranged from 8.6% to 11.1%, and the mutant line-9 had the highest content. The ratio of oleic to linoleic acid was 0.9 to 2.2. A negative coefficient (r=-0.98**) was obtained between oleic and linoleic acid, but for other fatty acids, no significant relation was observed. Similarly, a negative coefficient of r=-0.68**was observed between saturated and unsaturated acids. The sucrose compositions of mutants ranged from 2.6% to 6.2%.

• Journal of Radiation Protection and Research
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• 제39권3호
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• pp.150-158
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• 2014

각 의료기관 내 방사선 관련 종사자나 방사선 치료환자들은 진단 및 치료 시 필연적으로 의료상 피폭을 수반하게 된다. 국제방사선방호위원회(ICRP) 권고나 국제원자력기구(IAEA)의 기준에 따라 기준선량 제약치를 적용 및 권고 받고 있지만 1차 피폭대상자인 종사자나 환자들의 피폭최적관리를 위해서는 잠재적인 피폭대상자들에게 기존의 피폭관리 시스템보다 직접적이고 가용성이 높은 측정 및 분석 방법이 필요하다. 따라서 본 연구에서는 기존에 구비된 휴대용 단말과 연동하여 원거리에서 실시간으로 방사선 모니터링이 가능한 시스템을 개발하였다. 모니터링 시스템은 검출부, 영상부, 통신부 세 부분으로 구성되었다. 검출부는 시스템의 소형화를 위해 실리콘 광증배소자(silicon photomultiplier) 기반 섬광검출기를 설계하였으며, 영상부는 무선 CCD (charge-coupled device)카메라 모듈을 사용하여 검출부와 함께 Bluetooth 통신모듈을 통해 휴대용 단말로 측정된 방사선 정보와 영상이 전송된다. 제작된 시스템은 성능 평가를 위해 진단용 X-ray 발생장치와 $^{137}Cs$, $^{22}Na$, $^{60}Co$, $^{204}Tl$, $^{90}Sr$ 선원을 사용하였다. 측정결과를 통해 개발된 시스템은 gamma, beta, X-ray에 대해서 검출 반응성을 확인하였고, 방사선 세기에 따른 응답 선형성과 MCNPX 전산코드를 이용한 측정 거리에 따른 시스템의 검출 정확도 평가 시 3% 내외의 오차범위를 확인하였다. 본 연구의 결과는 방사선 검출 시스템 구성의 비용절감 효과와 개인피폭정도관리에 기여할 것으로 기대한다.

• Nuclear Engineering and Technology
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• 제51권8호
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• pp.1991-1997
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• 2019

In this manuscript, we present a method for the direct calculation of an ambient dose equivalent (H^* (10)) for the external gamma-ray exposure with an energy range of 40 keV to 2 MeV in an electronic personal dosimeter (EPD). The designed EPD consists of a 3 × 3 ㎟ PIN diode coupled to a 3 × 3 × 3 ㎣ CsI (Tl) scintillator block. The spectrum-to-dose conversion function (G(E)) for estimating H^* (10) was calculated by applying the gradient-descent method based on the Monte-Carlo simulation. The optimal parameters for the G(E) were found and this conversion of the H^* (10) from the gamma spectra was verified by using ²⁴¹Am, ¹³⁷Cs, ²²Na, ⁵⁴Mn, and ⁶⁰Co radioisotopes. Furthermore, gamma spectra and H^* (10) were obtained for an arbitrarily mixed multiple isotope case through Monte-Carlo simulation in order to expand the verification to more general cases. The H^* (10) based on the G(E) function for the gamma spectra was then compared with H^* (10) calculated by simulation. The relative difference of H^* (10) from various single-source spectra was in the range of ±2.89%, and the relative difference of H^* (10) for a multiple isotope case was in the range of ±5.56%.

• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3913-3923
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• 2023

Todays, medium energy resolution detectors are preferably used in radioisotope identification devices(RID) in nuclear and radioactive material categorization. However, there is still a need to develop or enhance « automated identifiers » for the useful RID algorithms. To decide whether any material is SNM or NORM, a key parameter is the better energy resolution of the detector. Although masking, shielding and gain shift/stabilization and other affecting parameters on site are also important for successful operations, the suitability of the RID algorithm is also a critical point to enhance the identification reliability while extracting the features from the spectral analysis. In this study, a RID algorithm based on Bayesian statistical method has been modified for medium energy resolution detectors and applied to the uranium gamma-ray spectra taken by a LaBr3:Ce detector. The present Bayesian RID algorithm covers up to 2000 keV energy range. It uses the peak centroids, the peak areas from the measured gamma-ray spectra. The extraction features are derived from the peak-based Bayesian classifiers to estimate a posterior probability for each isotope in the ANSI library. The program operations were tested under a MATLAB platform. The present peak based Bayesian RID algorithm was validated by using single isotopes(²⁴¹Am, ⁵⁷Co, ¹³⁷Cs, ⁵⁴Mn, ⁶⁰Co), and then applied to five standard nuclear materials(0.32-4.51% at.²³⁵U), as well as natural U- and Th-ores. The ID performance of the RID algorithm was quantified in terms of F-score for each isotope. The posterior probability is calculated to be 54.5-74.4% for ²³⁸U and 4.7-10.5% for ²³⁵U in EC-NRM171 uranium materials. For the case of the more complex gamma-ray spectra from CRMs, the total scoring (ST) method was preferred for its ID performance evaluation. It was shown that the present peak based Bayesian RID algorithm can be applied to identify ²³⁵U and ²³⁸U isotopes in LEU or natural U-Th samples if a medium energy resolution detector is was in the measurements.

• 공업화학
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• 제10권6호
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• pp.838-842
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• 1999

하수종말처리장에서 배출되는 유출수를 공업용수로 재이용하고자 방사선 조사방법을 이용하였다. 시료는 유출수를 모래여과한 후 사용하였다. 방사선원으로는 Co-60가 사용되었으며 조사량은 1 kGy부터 15 kGy로 변화시켰다. 하수처리수를 공업용수로 재활용하고자 할 때 가장 제거하기 어려운 색도의 주 원인물질은 휴민물질이었다. 이들은 방사선 조사선량 5 kGy에서 잘 제거되었다. 박테리아 역시 낮은 조사선량에서 살균이 이루어졌다. 그렇지만 방사선처리 후에도 여전히 미량의 유기물은 제거되지 않음을 알 수 있었다. 따라서 좀더 높은 질의 공업용수를 요구하는 곳에 이들을 재활용하고자 할 경우에는 추가적인 처리공정이 필요할 것이다.

• Journal of Radiation Protection and Research
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• 제34권1호
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• pp.9-14
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• 2009

High density polyethylene (HDPE) is degraded due to a radiation-induced oxidation when it is used as a neutron moderator in a neutron counter for a nuclear material accounting of spent fuels. The HDPE exposed to the gamma-ray emitted from the fission products in a spent nuclear fuel results in a radiation-induced degradation which changes its original molecular structure to others. So a neutron moderating power variation of HDPE, irradiated by a gamma radiation, was investigated in this work. Five HDPE moderator structures were exposed to the gamma radiation emitted from a $^{60}Co$ source to a level of $10^5-10^9$ rad to compare their post-irradiation properties. As a result of the neutron measurement test with 5 irradiated HDPE structures and a neutron measuring system, it was confirmed that the neutron moderating power for the $10^5$ rad irradiated HDPE moderator revealed the largest decrease when the un-irradiated pure one was used as a reference. It implies that a neutron moderating power variation of HDPE is not directly proportional to the integrated gamma dose rate. To clarify the cause of these changes, some techniques such as a FTIR, an element analysis and a densitometry were employed. As a result of these analyses, it was confirmed that the molecular structure of the gamma irradiated HDPEs had partially changed to others, and the contents of hydrogen and oxygen had varied during the process of a radiation-induced degradation. The mechanism of these changes cannot be explained in detail at present, and thus need further study.

• Journal of Ginseng Research
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• 제15권3호
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• pp.171-178
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• 1991

The results ok feeding experiments to the mice with ginseng extract, ginseng Powder, and ADAPTAGEN, for 30 days before X-ray irradiation and for 40 days after the X-ray irradiation at 750 rads were as follow: 1. The 50% lethals days (LD50, ) by the X-ray irradiation were 9 days at 1, 000 rads. 10 days at 900 rads, 11 days at 800 rads, 14 days at 760 rads, and 19 darts at 750 rads. Therefore, the standard radiation dose was set at 750 radb/8 min. 2. The 80% of the control group mice exposed to the X-ray radiation without ginseng feeding died in periods ranging from 14 to 24 days and the 20~30% of the ginseng extract and ginseng powder feeding groups died. But the 100% of the mice fed with ADAPTAGEN survived. 3. Testicles of the control group became smaller in weight than the nomad group by 26.5 to 29.0% and those of the ginseng extract and ginseng powder feeding group reduced by 44.6 to 60.4%. However, testicles of the ADAPTiIGEN feeding group increased in size by 77.4% to 87.1% and in weight by 61%, showing a recovery phenomenon approarhing to those of the ordinary mice. The ADAPTAGEN feeding group mice were also as active in color as the ordinary ones. 4. An electron micrograph(X8, 000X2.2) of the liver cells of the mice which had been 40 days after X-ray irradiation showed as follows; The control group appeared that is physiological action stopped due to the frequent occurrence of morphological change of the nucleus and diffusion of chromosome, reduction in microspores and expansion of microsomts, and endoplasmic change of mitochondria. The liver cells or the ADAPTAGEN feeding group were in a state similar to those of the ordinary mice restoring to normalcy In contrast, the liver cells of the ginseng extract and ginseng powder feeding groups were still far from being normal. 5. A serological analysis showed that the control group sharply decreased in albumin, Y-g1obu1in, and IgG so far as to cause dystrophy and to weaken antibody resistance but that ginseng extract and ginseng powder feeding groups, though in a little more restoring state than the control group, were still far from the normal group. The ADAPTAGEN feeding group restored to a state as comparable to the normal group in the contents of albumin ${\gamma}$-globulin, IgG and serum protein. In order words, it is noteworthy that ADAPTAGEN feeding was effective in revitalizing the destroyed cells of a living body and that it has the function of normalizing antibody components.

• Nuclear Engineering and Technology
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• 제34권6호
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• pp.545-552
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• 2002

We developed an ultra low background gamma ray spectrometer particularly suitable for experiment which require lower detection limit. The background of a germanium spectrometer is suppressed by applying active and passive shielding technique at the same time. The active shielding devices consist of plastic scintillating plates of 50 mm thick and anti-coincidence electronic system. The shielding is made of 150 mm thick walls of very low activity lead,20 mm with activity of <10 Bq/kg and 130 mm with activity of <50 Bq/kg. The observed background count rates are 1.2 $s^{-1}$ and 0.36 $s^{-1}$ without and with the active shielding, respectively, overall the energy regions from 30 keV to 3 MeV The cosmic ray induced background is suppressed by a rate of 0.8 $s^{-1}$ at the present work. The detection efficiency curve necessary to obtain the radioactivity of environmental samples has been precisely determined on the energy regions from 80 to 2000 keV with a 10$^3$ ml marinelli beaker sample, consisting of the calibrated radionuclides $^{109}$ Cd, $^{57}$ CO, $^{139}$ Ce, $^{203}$ Hg, $^{113}$ Sn, $^{85}$Sr, $^{137}$ Cs, $^{60}$ Co and $^{88}$ Y. Virtues Of the method are demonstrated by measuring the activity of $^{137}$ Cs contained in the powdered milk.

• 대한방사선기술학회지:방사선기술과학
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• 제44권2호
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• pp.117-122
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• 2021

This study is desinged to examine for radiation protection effect of Protaetia Brevitarsis Larvae extracts on the blood and prostate of male rat as a natural radiation protection agent. 5 groups were classified using 90 male rat as experimental animals. Each group was clssified as normal control group (NC Group), the group administered protaetia brevitarsis larvae extracts (PBE Group), irradiated group (IR Group), irradiated group after administration of protaetia brevitarsis larvae extracts (PBE+IR Group), the group administered protaetia brevitarsis larvae extracts after irradiaton (IR+PBE Group). In IR Group, 7 Gy/h of Co-60 gamma ray was irradiated to SD rats. In PBE+IR Group, protaetia brevitarsis larvae extacts wewe injected at 200 mg/kg/day for 14 days before irradiation, In IR+PBE Group, protaetia brevitarsis larvae extract was injeted after irradiation. On the 1, 7 and 21 days after irradiation, the experimental animals were sacrificed to evaluate the changes in blood cell component, superoxide dismutase (SOD) activity, histopathological evaluation of the liver and prostate gland. As a result, the PBE+IR Group and IR+PBE Group showed a significantly recovery of white blood cell (p<0.01, p<0.01), platelet (p<0.01, p<0.01) than the IR Group. It was also confirmed that SOD activity of PBE+IR Group (p<0.01) and IR+PBE Group (p<0.01) was significantly increased than the IR Group. Also PBE+IR Group and IR+PBE Group showed less inflammatory reactions of cystoplasm in the prostate gland than the IR Group. In conclusion, the protaetia brevitarsis larvae have radioprotection effect against blood and prostate gland. It is expected to be useful for research of radiation protection agent.

• Journal of Pharmaceutical Investigation
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• 제23권3호
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• pp.145-153
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• 1993

Retaining a drug in the stomach by some means is sometimes necessary to extend the G1 absorption time of the drug more than 6-8 hrs. Hydrogel has often been examined for its feasibility as a dosage form, so called platform, that could be retained in the stomach due to its excellent swelling properties in the gastric fluid. In this study, polyvinylpyrrolidone (PVP) hydrogel crosslinked by albumin or acrylated albumin was synthesized in a tablet form and evaluated for its possibility as the platform. The synthesis of the hydrogel was performed by $^{60}Co\;{\gamma}-ray$ irradiation of N-vinyl-2-pyrrolidone (monomer) in the presence of a crosslinking agent: aqueous solution of albumin or acrylated albumin. Synthetic conditions such as radiation dose, dose rate and concentration of crosslinking agent were varied in order to optimize the swelling and mechanical properties of the hydrogels. Degree of swelling of albumin-crosslinked PVP (Al-PVP) was highly dependent on radiation dose, dose rate and albumin concentration: it was decreased as they increased. On the other hand, that of acrylated albumin-crosslinked PVP (Acryl-PVP) was almost independent on them except dose rate: it was decreased as the radiation dose rate increased. The compressive strength of the two hydrogels was decreased as the dose rate increased. Digestion of both PVP in artificial gastric fluid containing pepsin was delayed by the ${\gamma}-ray$ irradiation. In conclusion, Al-PVP and Acry-PVP with diverse swelling and mechanical properties could be obtained by controlling synthetic conditions, mainly the irradiation dose rate.