• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.948-949
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• 2016

In this study, we perform the structure change of the shielding this is applied for gamma-ray detectors for imaging of gamma-ray source. Through previous studies, we implemented the commercially available gamma-ray imaging apparatus similar to the shielding body but weight reduction, center of gravity moving of shield. In this paper, we changed a shield for motion control detectors efficient movement. We performed the MCNP simulation of shield design and then we obtained the results of reducing the weight of the 17% and moving of center of gravity the shield center.

• Journal of Sensor Science and Technology
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• v.4 no.4
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• pp.1-9
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• 1995

The ${\gamma}$-ray deposition spectra were calculated by Monte Calro method to obtain the scintillation characteristics of the ${\gamma}$-ray for BGO scintillation detector with the spherical shape of 1.25 cm radius. The code used in calculating the ${\gamma}$-ray deposition spectra was made for personal computer with qbasic language. Also the ${\gamma}$-ray energy spectra of $^{22}Na$, $^{137}Cs$ and $^{207}Bi$ were measured with the detector. The energy dependent resolution below 2000 keV for the detector was determined by estimating the standard deviation of the photopeak fitted with gaussian function, and $X^{2}$ fitting using Nardi's empirical formula. The measured spectra of $^{22}Na$ and $^{137}Cs$ were compared with the broadened spectra which were obtained by broadening the calculated ${\gamma}$-ray deposition spectra with the energy dependent resolution. The absolute efficiency and the intrinsic peak efficiency of the detector were obtained by calculating the ${\gamma}$-ray deposition spectrum with the code.

• Research in Plant Disease
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• v.22 no.2
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• pp.94-99
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• 2016

For the purpose of practical application of gamma irradiation for export lily without the ionic energy damage, 150 Gy gamma ray was suggested as the safe level on cut lilies, the oriental cultivar Siberia (white) and Sorbonne (pink). The combined treatments of 150 Gy gamma ray and sodium dichloroisocyanurate (NaDCC) at 0, 40, 100, and $200{\mu}g/l$, were tried to control lily leaf blight caused by Botrytis elliptica. Incidences of petal blight on the two oriental lilies at control were 93%-95%, whereas those at the combined treatments of 150 Gy and $100{\mu}g/l$ or higher of NaDCC were 76%-83%. However, severity of petal blight was not reduced by the combined treatments. Gamma irradiation at 150 Gy did not change the cut lily quality such as improve cut lily longevity of vase-life compare with the control. In addition, fresh weight, chlorophyll contents, and the color of pink petals of Sorbonne were not changed by 150 Gy of gamma irradiation. Therefore, we recommend the combined treatment of 150 Gy gamma irradiation and $100{\mu}g/l$ NaDCC for the standard operating procedure on cut lily for export quarantine to control leaf blight.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.673-678
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• 2003

Changran Jeotgal (aged and seasoned intestine of Alaska pollack) was prepared as the same method as commercial one and irradiated at 0, 2.5, 5.0 and 10 k㏉ by gamma ray for industrial application. Changran Jeotgal using 10 k㏉-irradiated red pepper powder was also prepared to compare with control (0 k㏉). Commercial red pepper powder was already contaminated at 3.8$\times$10$^{6}$ CFU/$m\ell$ level by total plate count and 10k㏉ of irradiation reduced the number about 4 log cycles. Gamma irradiated Changran Jeotgal at 2.5,5.0, and 10k㏉ showed 3 6, and 7 log cycles of reduction compared to the non-irradiated control in the total plate count after 12 weeks of storage at 1$0^{\circ}C$. Using irradiated (10k㏉) red pepper powder reduced the microbial contamination significantly by 2 log cycles compared to the control. Sensory evaluation showed that the sample irradiated at 2.5 k㏉ was the most acceptable, followed by the sample using irradiated red pepper powder and non-irradiated control. Thus, 2.5 k㏉ of irradiation of Changran Jeotgal was effective to improve safety during distribution and storage without change of sensory quality. Furthermore, using the irradiated red pepper powder is also recommended for safety enhancement of the products.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.822-827
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• 2000

Gamma irradiation was applied to reduce shrimp allergy. Shrimp heat-stable protein(HSP) and shrimp protein extract were gamma-irradiated at 1, 3, 5, 7 or 10 kGy in an aqueous state (1.0 mg/mL). The changes in allergenic and antigenic properties of protein extract and HSP resulted from gamma irradiation were monitored by ELISA with mouse mAb or human patients sera and immunoblotting. Conformational changes in irradiated HSP were measured by both GPC-HPLC and SDS-PAGE. The binding ability of shrimp allergic patients IgE to irradiated protein extract or irradiated heat-stable protein was dose-dependently reduced. When measured by gel permeation chromatography and sandwich ELISA, the amount of intact heat-stable protein in the irradiated solution was reduced by gamma irradiation depending upon the applied dose. SDS-PAGE showed that the main band disappeared and new bands appeared in a higher molecular weight zone. The results provide a new possibility to use irradiation process for reducing the allergenicity of shrimp.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.2
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• pp.97-104
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• 2004

Neutron induced prompt gamma-ray spectroscopy(NIPS) system measures the prompt gamma-ray emitting by the interaction of a neutron with various materials. This system will be of great benefit to scientists worldwide, since it provides the non-destructive measurement of many element in either solid or liquid wastes. In this study, the full-energy-peak (FEP) efficiency calibration for a HPGe detector was constructed in the ${\gamma}$-ray energy range from 80 keV to 8 MeV, using $^{l33}$Ba and >TEX>$^{152}Eu$ RI sources and $ ^{35}Cl(n, ${\gamma}$)^{36}Cl$ thermal neutron captured reaction. The FEP efficiency curve for the higher energies using the $^{35}Cl(n, ${\gamma}$)^{36}Cl$ reaction was normalized with the curve obtained from the RI sources, since the accurate activity of its prompt ${\gamma}$-ray is unknown. The average thermal neutron flux was theoretically calculated using the FEP efficiency curve for the KCl standard solutions. The NIPS system equipped with a ${\gamma}$-${\gamma}$ coincidence setup with two n-type coaxial HPGe detectors was considered in order to reduce the interfering ${\gamma}$-ray background. The FEP efficiency curve for the ${\gamma}$-${\gamma}$ coincidence system was also obtained for full energy range. The performance of the normal and coincidence NIPS system was tested by comparing signal-to-noise ratio in each mode using the reference sample.e.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.640-645
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• 2000

The effect of gamma-irradiation on the quality changes of the grain shape improved Meju was studied. Meju was prepared, irradiated at 0, 5, 10 and 20 kGy, and then stored at $25^{\circ}C$ for six months. The results showed that the fungi and acid producing bacteria were completely eliminated by gamma-irradiation with dose of 10 kGy or higher and the Bacillus was decreased by 5 log cycles with dose of 10 kGy. The $D_{10}$ values of the fungi, Bacillus and acid producing bacteria were 0.79, 2.28 and 1.17 kGy, respectively. Also, the microorganisms that survived irradiation was decreased significantly with the duration of storage period. The $NH_3-nitrogen$, negative factors of quality of Meju, and browning were repressed and the protease activity and pH were not affected by gamma-irradiation. Therefore, it was considered that the Meju treated with gamma-irradiation maintained better quality than that of the control with storage.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.1
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• pp.49-57
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• 2008

In order to control or kill insects and pests, control ripening, and delay spoilage, kiwifruits were irradiated with gamma rays at 0.1, 0.3, and 0.5 kGy. Vitamin C, hydrogen donating activity, sugar content, organic acid content, texture, chromaticity, and sensory qualities were examined in the fruits over 2 weeks of storage at 20$^{\circ}C$. Vitamin C content and hydrogen donating activity decreased during the storage period, but they were not reduced by the irradiation process. Total sugar and reducing sugar contents increased as the storage period increased; however, these were also unaffected by irradiation. Organic acid content significantly decreased as a result of irradiation, and all samples had decreases in organic acids over the storage period. Hardness decreased with the storage period as well as with increasing doses of irradiation. In terms of Hunter's color values, irradiation increased the $L^*-\;and\;a^*-$ values in the initial storage period, but it did not have any significant effect on these values during the 2 weeks of storage. When compared with control samples, the irradiated samples had lower color and overall acceptability scores just after irradiation (week 0). However, during the storage period, the irradiated samples had higher scores for smell, taste, texture, and overall acceptability than the control. In conclusion, based on the results, gamma irradiation up to 0.5 kGy is the recommended treatment to maintain the overall quality attributes kiwifruit.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.6
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• pp.989-996
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• 2008

In this study we assessed the effects of gamma irradiation ($0.5{\sim}3\;kGy$) on the microbial and physico-chemical characteristics of maesil (Prunus mume) stored for 9 days at $20^{\circ}C$. Total aerobic bacteria, yeasts and molds were significantly decreased with increases in the irradiation dosage. In terms of the Hunter's color value, irradiated samples evidenced a higher b-value, but a lower a-value than the non-irradiated samples. Hardness was reduced with increment in the irradiation dose level. The contents of total sugar, hydrogen donating activity and organic acids were not affected by irradiation. The reducing sugar contents of the irradiated samples were superior to those of the non-irradiated samples. Vitamin C contents were reduced with the progression of storage periods and increases in the dosage level. These results demonstrated that gamma irradiation of 0.5 to 3 kGy affected the microbiological safety of maesil, but did not affect the physico-chemical characteristics(total sugar, hydrogen donating activity and organic acid) but the Hunter's color value, hardness, and vitamin C contents of the maesil deteriorated with gamma irradiation.

• Food Science and Preservation
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• v.15 no.4
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• pp.606-611
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• 2008

Myungran Jeotkal, Korean fermented seafood, and its ingredients(hot red pepper powder, ginger, garlic, and seasoning mix) were irradiated with 0, 0.5, 1.0, 2.0, and 5.0 kGy of gamma rays and stored at 4C for 4 weeks to determine changes in microbiological and sensory characteristics. Water activities of Myungran Jeotkal, hot red pepper powder, ginger, garlic, and seasoning mix were 0.89 0.56, 0.98, 0.99, and 0.07, respectively. Myungran Jeotkal was observed to be initially contaminated. Total aerobic bacteria, yeast and mold, and coliform levels were 6.7, 4.3, and 3.6 log CFU/g, respectively. Irradiation at 2 kGy afforded approximately a 4 log reduction in total aerobic bacteria, and a 3 log drop in both yeast and mold levels and coliform bacteria(P<0.05). No viable microbial cells were detected in Myungran Jeotkal after 5 kGy of irradiation(at a detection limit of 101 CFU/g). The total aerobic bacterial level in red pepper powder was 6.3 log CFU/g and this component, of the tested ingredients, contributed most to the microbial contamination of Myungran Jeotkal. The initial count of total aerobic bacteria, 6.3 log CFU/g, was significantly reduced to 4.5 log CFU/g after irradiation(P<0.05). Sensory evaluation showed that gamma irradiation of up to 5.0 kGy did not adversely affect overall acceptability of Myungran Jeotkal or its ingredients during cold storage. Therefore, gamma irradiationwas effective to extend the shelf-life of Myungran Jeotkal.