• 한국작물학회지
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• 제7권1호
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• pp.129-132
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• 1969

The polygenic variation in flowering time of soybean irradiated with Co$^{60}$ gamma ray evaluated in the R$_2$ generation. The genetic variance in the irradiation treatment was about four times that of the control. The basic possibility of selection for the early and the late in flowering time of soybean after irradiated with Co$^{60}$ was suggested in this paper.

• 대한방사선기술학회지:방사선기술과학
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• 제13권1호
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• pp.29-35
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• 1990

In a attempt to find out the effects of the irradiation on the lymphatic organs of birds, a total of 40 chickens(4 week old) were selected at random and alloted to control and experimental groups. The experiments were irradiated Co-60 ${\gamma}-ray/400$ rads, and then the enzyme histochemical activity of Bursa Fabricious(BF), thymus and spleen and hematological changes were compared with those of controls for 30 days(24 hrs., 5, 10, 20 and 30 days). The results obtained were summarized as follows: 1. The activity of acid phosphatase(ACP) of the reticuloendothelial cells of BF, thymus and spleen and the epithelia of BF of the experiments were increased significantly from the early experimental terms and then returned to the same level of controls through the late experimental terms. 2. The activity of nonspecific esterase(NSE) of the constituent cells with exception of the lymphocytes in BF, thymus and spleen of experiments were increased significantly from the early experimental terms and then returned to the same level of control through the late experimental terms. 3. The lymphocyte percentage, total erythrocytes and homoglobin of the experiments were severely decreased from early experimental terms and then increased to the normal levels of them incontrols.

• Nuclear Engineering and Technology
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• 제31권3호
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• pp.287-293
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• 1999

To assess the effects of gamma-ray (Co-60) on radiation sensitivity and genetic similarity of the basidiospore and mycelium in oyster mushroom, Pleurotus ostreatus, the D$_{10}$ values and RAPD patterns were analysed. Three strains were isolated from basidiospores (PO-Bl, -B2, and - B3 from 2 kGy irradiation group) and five strains from mycelia (PO-Ml, -M2 from 1 key, PO-M3 from 2 kGy, and PO-M4 and -M5 from 2+1 key irradiation group). The D$_{10}$ values of basidiospore and mycelium of P. Preurotus ostreatus were 1,250 Gy and 500 Gy, respectively. The growth rates of the eight strains on the five media were various and the activities of extracellular chitinases of them were generally higher than those of the control. By the gamma-ray radiation, 22-25% of genetic similarities were changed in the basidiospore strains and 23-36% of them in the mycelium strains. From these results, it seems that the basidiospore could be more radio-resistant than the mycelium of P. ostreatus and that the genetic similarity of the mycelium of P ostrentus could be changed easier than that of the basidiospore by the gamma-ray radiation.ion.

• Journal of Plant Biotechnology
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• 제30권2호
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• pp.201-206
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• 2003

Differential responses of red pepper plant and cultured cells to enhanced ${\gamma}$-ray($^{60}$ Co) and ultraviolet(UV) stress were investigated. In seed treatment, 1 Gy of ${\gamma}$-ray increased seedling dry weight up to 19.1%, but 50 Gy treatment markedly ingibited seed germination and subsequent growth of seedling. UV treatment to seed did not change the germination ability of seeds and the growth of seedlings regardless of duration of UV treatment until 24 hrs. In case of UV treatment to seedlings, plant injury was seriously progressed even after the seedlings were returned to no UV condition, and eventually all the leaves showed chlorosis by the stress. However, progress of plant injury by ${\gamma}$-ray stress slower than that caused by UV stress, and even at the high dose of ${\gamma}$-ray 50 Gy, did not caused the cholrosis of stressed plant leaf. Amount of electrolytes leakage from plant leaf by UV treatment for 24hrs was increased up to 28.8 folds in comparison with untreated control, whereas that of 50 Gy of ${\gamma}$-ray was increased only 1.2 folds. UV stress induced the production of capsidiol, antimicrobial phytoalexin, by activation of gene expression involved in capsidiol biosynthesis, such as sesquiterpene cyclase and cyclase and cytochrome P450 hydroxylase in the leaf and cultured cell, but ${\gamma}$-ray stress induced neither the production of capsidiol nor expression of the genes.

• 자원환경지질
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• 제9권3호
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• pp.135-141
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• 1976

The gamma-gamma logging method appplying in geophysical research are presented in this paper_ The logging probe assembly was designed which permits changing the source-to-detector spacing while conditions of proceeding ${\gamma}-{\gamma}$ logging, which a collimated gamma ray source ($^{60}Co$, 0.5mCi and/or 2 mCi) is separated from the scintillation detector as shown in Fig. 2 and 3, size is 6.0 cm in diameter and 120.0 cm in long and the exposed parts are made of stainless steel pipe. The results is confirmed by the experiment performed mainly in granite rock where a slightly constant shape was obtained but sometimes was shown sharpness shape for the measured scattered gamma-ray intensity. Consequently, the experimental results are obtained an adequate intensity of scattered gamma-rays and favourable response to density change, and also very closely correspond to between core samples of the test boring and to used this method of ${\gamma}-{\gamma}$ logging in the test bore-hole of the strata.

• Radiation Oncology Journal
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• 제3권2호
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• pp.145-151
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• 1985

Wedge filter를 사용할 때 $^{60}Co\;\gamma$선과 10MV X-선의 주변선량분포를 반자동식 물팬톰장치에 의해 제어되는 고체 방사선검출기로 측정하였다. wedge filter의 날과 등의 방향을 잇는 주단면상에서 주변선량을 측정하였다. 방사선의 투과력과 wedge 각, wedge에 대한 방향, 조사면의 변화에 대하여 주변선량의 면화를 고찰하였다. 선축에 수직인 방향의 측정은 깊이 dm, 5cm, 10cm, 15cm에서 선측과 평행인 방향에서는 조사면 경계에서 3cm, 5cm, 10cm 떨어진 위치에서 측정이 이루어졌다. 측정으로부터 wedge가 사용되는 조사면에 대한 주변선량분포가 아래와 같음을 볼 수 있었다. 1. wedge filter의 날의 방향의 주변선량이 등의 방향의 주변선량보다 높았다. 2. 표면근처에서는 깊이가 깊어짐에 따라 선량이 감소하였다. 3. $^{60}Co\;\gamma$선의 경우 어떤 깊이에서는 조사면의 경계로부터 거리가 떨어짐에 따라 주변선량이 단조감소하지 않고 다시 증가하는 영역이 있었다. 4. wedge를 사용하는 경우 주변선량은 방사선의 투과력이나 조사면의 크기뿐만 아니라 wedge의 각과 방향에도 영향을 받는다.

• Journal of Astronomy and Space Sciences
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• 제18권1호
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• pp.71-80
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• 2001

KITSAT-1에 탑재된 Total Dose Experiment (TDE)로 부터 관측된 RADFET의 문턱전압 변화를 원자력 연구소 조사실의 Co-60 감마선 조사 장치를 이용한 보정 실험을 통해 총 방사능양으로 환산하였다. 위성 내 센서의 위치에 따라 측정되는 총 방사능양이 다르게 나타났으며, 지구 자기권에서의 NASA 방사선 모델을 이용한 시뮬레이션을 통해 이러한 차이가 센서 위치에 따라 위성체에 의한 차폐 효과가 다르기 때문에 나타나는 현상임을 확인하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.275.1-275.1
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• 2014

The effects of the interfacial buffer layer and temperature on the organic bulk heterojunction (BHJ) nanostructures of copper phthalocyanine (CuPc) and fullerene (C60) systems were investigated using real time in-situ x-ray scattering. In the CuPc:C60 BHJ structures, standing-on configured ${\gamma}$-CuPc phase was formed by co-deposition of CuPc and C60. Once formed ${\gamma}$-phase was thermally stable during the annealing upon $180^{\circ}C$. Meanwhile, the insertion of CuI buffer layer prior to deposition of the CuPc:C60 BHJ layer induced lying-down configured CuPc crystals in the BHJ layer. The lying CuPc peak intensity and the lattice parameter were increased by the thermal annealing. This increment of the intensity seemed to be related to the strain at the interface between CuPc:C60 and CuI, which was proportional to the enhancement of the power conversion efficiency of the device.

• Journal of Radiation Protection and Research
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• 제40권2호
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• pp.73-78
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• 2015

본 연구에서는 실리콘 광 증배소자(Silicon photomultiplier)와 Ce:GAGG 섬광체 단결정을 이용한 섬광검출기를 제작하고, 감마선 분광특성 분석을 통해 기존에 상용화된 LYSO, CsI:Tl 섬광체와의 분광특성을 비교하였다. 섬광체 단결정의 크기는 $3{\times}3{\times}20mm^3$ 이며 $3{\times}3mm^2$ 실리콘 광 증배소자를 이용하여 섬광검출기를 제작한 후, 표준 감마선원인 $^{133}Ba$, $^{22}Na$, $^{137}Cs$, $^{60}Co$에 대한 에너지 분해능을 각각 측정하고 비교하였다. 그 결과 Ce:GAGG 섬광검출기의 감마선에 대한 에너지 분해능은 $^{133}Ba$ 0.356 MeV에서 13.5%, $^{22}Na$ 0.511 MeV에서 6.9%, $^{137}Cs$ 0.662 MeV에서 5.8% 그리고 $^{60}Co$ 1.33 MeV에서 2.3%의 분광 특성을 확인 할 수 있었다.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1754-1759
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• 2022

The activity of gamma-ray emitting nuclides is calculated assuming that each gamma-ray is detected individually; thus, the magnitude of the coincidence summing signal must be considered during activity calculations. Here, the correction factor for the coincidence summing effect was calculated, and the detection efficiencies of two HPGe detectors were compared. The CANBERRA Inc. GC4018 high-purity Ge detector provided an estimate for the peak-to-total ratio using a point source to determine the coincidence summing correction factor. The ORTEC Inc. GEM60 high-purity Ge detector uses EFFTRAN in LVis to obtain the parameters of the detector and source model and the gamma-gamma and gamma-X match estimates, in order to determine the coincidence summing correction factor. Nuclide analyses, radioactivity comparisons, and analyses of reference material samples were performed utilizing certified reference materials to accurately determine the detection efficiencies. For both Co-60 and Y-88, the detection efficiency for a point source increased by an average of at least 12-13%, whereas the detection efficiency determined using LVis increased by an average of at least 13-15%. The calculated radioactivity values of the certified reference material and reference material samples were accurate to within 3% and 6% of the measured values, respectively.