• 한국산학기술학회논문지
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• 제4권3호
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• pp.223-229
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• 2003

ICRP-60 신권고에 맞게 수정된 방사선피폭선량 계산프로그램인 K-DOSE 60을 4개 발전소 (고리, 월성, 울진, 영광)에 적용하여 주변주민 최대개인피폭선량을 평가하였다 핵종, 장기, 경로별로 결정변수값들을 도출한 결과, 경로는 성인의 경우 농작물, 유아의 경우 우유가, 핵종은 ³H, /sup 133/Xe, /sup 60/Co (고리 1,2발전소), /sup 14/C, /sup 41/Ar(월성 1,2발전소)로 나타났으며, 모든 장기에 대한 피폭선량차이가 매우 작았다. "출력 대 입력" 변동에 근거한 민감도 분석결과, 핵종의 화학적 형태가 타 입력변수들보다 10² factor만큼 높은 민감도를 보였으며, 전이/농축계수에 의한 민감도는 섭취량이나 방출량의 그것에 비하여 상대적으로 매우 낮았다. PCC를 이용한 상관성 민감도의 경우는 4가지 입력변수 모두 0.97 이상의 높은 상관성을 보였다.

• Journal of Radiation Protection and Research
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• 제41권4호
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• pp.378-383
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• 2016

Background: Radiation dose rates in PRIDE facility is evaluated quantitatively for assessing radiation safety of workers because of large amounts of depleted uranium being handled in PRIDE facility. Even if direct radiation from depleted uranium is very low and will not expose a worker to significant amounts of external radiation. Materials and Methods: ORIGEN-ARP code was used for calculating the neutron and gamma source term being generated from depleted uranium (DU), and the MCNP5 code was used for calculating the neutron and gamma fluxes and dose rates. Results and Discussion: The neutron and gamma fluxes and dose rates due to DU on spherical surface of 30 cm radius were calculated with the variation of DU mass and density. In this calculation, an imaginary case in which DU density is zero was added to check the self-shielding effect of DU. In this case, the DU sphere was modeled as a point. In case of DU mixed with molten salt of 50-250 g, the neutron and gamma fluxes were calculated respectively. It was found that the molten salt contents in DU had little effect on the neutron and the gamma fluxes. The neutron and the gamma fluxes, under the respective conditions of 1 and 5 kg mass of DU, and 5 and $19.1g{\cdot}cm^{-3}$ density of DU, were calculated with the molten salt (LiCl+KCl) of 50 g fixed, and compared with the source term. As the results, similar tendency was found in neutron and gamma fluxes with the variation of DU mass and density when compared with source spectra, except their magnitudes. Conclusion: In the case of the DU mass over 5 kg, the dose rate was shown to be higher than the environmental dose rate. From these results, it is concluded that if a worker would do an experiment with DU having over 5 kg of mass, the worker should be careful in order not to be exposed to the radiation.

• Journal of Radiation Protection and Research
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• 제40권1호
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• pp.25-35
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• 2015

We analyzed the differential effects of histopathology, apoptosis and expression of radiation response genes after chronic low dose rate (LDR) and acute high dose rate (HDR) radiation exposure in spleen, lung and liver of rats. Female 6-week-old Sprague-Dawley rats were used. For chronic low-dose whole body irradiation, rats were maintained for 14 days in a $^{60}Co$ gamma ray irradiated room and received a cumulative dose of 2 Gy or 5 Gy. Rats in the acute whole body exposure group were exposed to an equal dose of radiation delivered as a single pulse ($^{137}Cs$-gamma). At 24 hours after exposure, spleen, lung and liver tissues were extracted for histopathologic examination, western blotting and RT-PCR analysis. 1. The spleen showed the most dramatic differential response to acute and chronic exposure, with the induction of substantial tissue damage by HDR but not by LDR radiation. Effects of LDR radiation on the lung were only apparent at the higher dose (5 Gy), but not at lower dose (2 Gy). In the liver, HDR and LDR exposure induced a similar damage response at both doses. RT-PCR analysis identified cyclin G1 as a LDR-responsive gene in the spleen of rats exposed to 2 Gy and 5 Gy gamma radiation and in the lung of animals irradiated with 5 Gy. 2. The effects of LDR radiation differed among lung, liver, and spleen tissues. The spleen showed the greatest differential effect between HDR and LDR. The response to LDR radiation may involve expression of cyclin G1.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 요약집 춘계학술발표대회
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• pp.396-396
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• 2004

• 방사선산업학회지
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• 제5권4호
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• pp.359-364
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• 2011

This study was aimed to investigate the effect of oxidants on biodegradability and decomposition of acetaminophen (ACT) by gamma ray. Three kinds of chemical, potassium persulfate, hydrogen peroxide and ferrous sulfate were selected as an oxidant. The absorbed dose was ranged from 0.2 to 10 kGy and the concentration of oxidants was from 0.1 to 10 mM and the initial concentration of acetaminophen was $30mg\;l^{-1}$ in this study. The concentration of ACT was gradually decreased corresponding to the increase of the absorbed dose. However, mineralization of ACT was not occurred by the increased of the absorbed dose. When the 10 mM of oxidants applied to the ACT aqueous solution, the concentration of ACT was rapidly decreased according to absorbed dose and the mineralization was observed in potassium persulfate. Biodegradability of ACT with potassium persulfate was higher than that of ACT without potassium persulfate in lower absorbed dose and decreased according to higher absorbed dose.

• Journal of Astronomy and Space Sciences
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• 제18권2호
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• pp.153-162
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• 2001

본 논문에서는 아리랑 2호가 운용될 궤도의 우주방사능 환경 및 total ionizing dose(TID) 영향에 대하여 분석하였다. 포획된 양자의 경우 SAA(South Atlantic Anomaly) 지역에 집중되어 있음을 알 수 있었으며, TID에 영향을 미치는 우주 방사능은 포획된 양자 및 전자와 태양양자임을 알 수 있었다. 저 에너지 입자는 알루미늄 차단 구조물을 이용하여 방사능 영향을 효과적으로 차단할 수 있음을 알 수 있었으나, 고 에너지 입자의 경우 구조물의 두께를 증가하여도 방사능 영향을 효과적으로 차단할 수 없음을 알 수 있었다. 아리랑 2호의 임무수명기간 동안 전자부품에 계속적으로 피폭되는 전체 방사량을 알루미늄 차단두께의 함수로 나타내었으며, 이 값들은 아리랑 2호의 전자부품의 선택기준 및 위성체 또는 구성품의 구조물 두께를 설정할 수 있는 기준으로 제시하였다.

• 대한방사선치료학회:학술대회논문집
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• 대한방사선치료학회 1996년도 16차 학술대회
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• pp.7-7
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• 1996

• 한국환경농학회지
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• 제19권4호
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• pp.324-327
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• 2000

저선량 조사한 대두종자의 초기생육과 대두 유식물체의 후속고선량에 대한 방사선 감수성 변화를 알아보고자 저선량 0, 4, 8, 12, 20 Gy를 조사하여 재배한 대두 유식물체에 ${\gamma}$선 50, 100, 200 Gy를 조사한 후 생육상황을 관찰하였다. 저선량 조사에 의해 대두 신규종자의 발아율 증가효과는 없었으나 작물 생장 증대효과는 있었으며 저선량 8 Gy 조사구가 가장 효과적이었다. 대두유식물체의 고선량 방사선에 의한 생육장해는 사전 저선량조사에 의해 크게 감소되었으며 저선량 조사에 의한 고선량 방사선 저항성 증가는 8 Gy와 20 Gy조사에서 가장 효과적이었다.

• Journal of Semiconductor Engineering
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• 제1권3호
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• pp.81-87
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• 2020

An instrumentation amplifier (IA) and an analog-to-digital converter (ADC) are essential circuit blocks for accurate and robust sensor readout systems. This paper introduces recent advances in radiation-hardening by design (RHBD) techniques applied for the sensor readout integrated circuits (IC), e.g., the three-op-amp IA and the successive-approximation register (SAR) ADC, operating against total ionizing dose (TID) and singe event effect (SEE) in harsh radiation environments. The radiation-hardened IA utilized TID monitoring and adaptive reference control to compensate for transistor parameter variations due to radiation effects. The radiation-hardened SAR ADC adopts delay-based double-feedback flip-flops to prevent soft errors which flips the data bits. Radiation-hardened IA and ADC were verified through compact model simulation, and fabricated CMOS chips were measured in radiation facilities to confirm their radiation tolerance.

• 전기전자학회논문지
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• 제15권2호
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• pp.143-148
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• 2011

MOS (Metal-Oxide Semconductor) devices among the most sensistive of all semiconductors to radiation, in particular ionizing radiation, showing much change even after a relatively low dose. The necessity of a radiation dosimeter robust enough for the working environment has increased in the fields of aerospace, radio-therapy, atomic power plant facilities, and other places where radiation exists. The power MOSFET (Metal-Oxide Semiconductor Field-Effect Transistor) has been tested for use as a gamma radiation dosimeter by measuring the variation of threshold voltage based on the quantity of dose, and a maximum total dose of 30 krad exposed to a $^{60}Co$ ${\gamma}$-radiation source, which is sensitive to environment parameters such as temperature. The gate oxide structures give the main influence on the changes in the electrical characteristics affected by irradiation. The variation of threshold voltage on the operating temperature has caused errors, and needs calibration. These effects can be overcome by adjusting gate oxide thickness and implanting impurity at the surface of well region in MOSFET.