• Food Science and Preservation
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• v.8 no.3
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• pp.291-295
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• 2001

Photostimulated luminescence (PSL) analysis was applied to determine whether some agricultural commodities of Korean and Chinese origins have been irradiated or not. Cereals (brown rice and buckwheat) and legumes (soybean, peanut, fed bean and mung bean) were exposed to gamma irradiation at 0.5 ∼4 kGy The Korean garlic was irradiated at 0.05 ∼0.5 kGy. Cereals and mung bean were tool applicable to the PSL measurement, showing the intermediate values between the lower (700 photon counts, negative) and the upper threshold values (5,000, positive), however PSL values determined for soybean, peanut, red bean and garlic were suitable for being discriminated between nonirradiated and irradiated samples. There was no significant difference in PSL properties accgrding to the sample origins.

• Preventive Nutrition and Food Science
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• v.5 no.3
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• pp.136-141
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• 2000

The properties of pulsed photostimulated luminescence (PPSL) were measured to use as basis data for the detection of irradiated foodstuffs (34 different foods). Samples were packed in polyethylene bags and irradiated at 1, 5, and 10 kGy with a dose rate of 10 kGy/h. The samples irradiated were introduced in the sample chamber without other preparation and measured PPSL photon counts for 60 and 120 s. The PPSL photo counts of the irradiated samples were higher than the unirradiated, increased with increasing irradiation dose, and showed a good relationship between irradiation doses and photon counts in a multinomial expression. These results suggest that the detection of irradiated foodstuffs was possible by PPSL. Therefore, PPSL can be proposed as the method for the detection of irradiated foodstuffs.

• Preventive Nutrition and Food Science
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• v.5 no.3
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• pp.142-147
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• 2000

To establish a detection method of irradiated perilla and sesame seeds, studies were performed with pulsed photostimulated luminescence (PPSL) and thermoluminescence (TL). The PPSL photon counts of the mineral separated from irradiated sesame and perilla seeds were higher than unirradiated one and exhibited an increase with increasing irradiation dose and mineral content. Also TL intensities of minerals separated from irradiated sesame and perilla seeds increased with increasing irradiation dose. In all samples, detection was possible with shapes and maximum TL temperatures of the second glow curves showing lower regions than those of the first glow curves and correctly classified as irradiated samples. Glow curve ratios of irradiated samples were higher than 0.5. These results suggest that PPSL and TL are applicable methods for the detection of irradiated perilla and sesame seeds.

• Preventive Nutrition and Food Science
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• v.10 no.2
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• pp.145-150
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• 2005

This study was carried out to examine the properties of sample amount and storage conditions on the accumulated pulsed photostimulated luminescence (PPSL) signals of soybean paste powder. Difference amounts (0.1, 0.5 and 1 g) of soybean paste powder samples stored in normal room and darkroom conditions were measured. The PPSL signals of the soybean paste powders significantly increased with irradiation dose up to 10 kGy. The PPSL signals of irradiated soybean paste powder samples decreased with increasing storage periods. The decay rates were similar to regardless of storage conditions and sample amount. The PPSL signals of the irradiated soybean paste powder measured for 120 s were higher than those measured for 60 s. These results indicated that although the PPSL signal of all soybean paste powder samples decreased with increasing storage time, detection of irradiated samples was still possible after 12 months of storage regardless of sample amount and measurement times in both normal room and darkroom conditions.

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.79-84
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• 2003

This study was carried out to establish a method for determining if granule-type Ramen soup powder has been irradiated. Thermoluminescence (TL) and pulled photostimulated luminescence (PPSL) were used as the detection methods through observed changes of TL and PPSL intensities after storage under differing conditions. PPSL intensities increased with increases in irradiation doses. The threshold level of PPSL was below 412$\pm$58 photon counts regardless of storage conditions (room and darkroom) after 10 months. TL intensities also increased with increasing irradiation doses. The coefficients ($R^2$) of PPSL (0.74~0.94) and TL intensities (0.92~0.58) were very highly correlated with irradiation dose. The PPSL and TL intensities were decreased after 10 months of storage. These results indicate that discrimination of irradiated from non-irradiated granule-type Ramen soup powder is possible using TL and PPSL methods despite the decrease in intensities of TL and PPSL with increasing storage times.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.232-235
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• 2010

This study examined the photostimulated luminescence (PSL) detection method suggested by the Korean Food and Drug Administration to assess whether the method can be used to identify irradiated spices in restructured pork patties, which served as a model system for processed meat products. Red and black pepper powders were irradiated at 0, 5.0, 7.5, and 10 kGy, and pork patties were formulated with the spice at irradiated pepper concentrations of 0.1% and 0.5%. PSL was then used to estimate amounts of light derived from the spice itself and pork patties. The results of PSL analysis showed that red and black pepper powders were determined as positive and presumptive positive, respectively, when irradiated at more than 7.5 kGy. However, when used in pork patties, all samples were negative for irradiation. Thus, PSL may not be useful in detecting irradiated ingredients used in processed meat products.

• International Journal of Korean Welding Society
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• v.3 no.2
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• pp.29-39
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• 2003

The durability and reliability of thermal barrier coatings (TBCs) play an important role in the service reliability, availability and maintainability (RAM) of hot­section components in advanced turbine engines for aero and utility applications. Photostimulated luminescence spectroscopy (PSLS) and electrochemical impedance spectroscopy (EIS) are being concurrently developed as complimentary non­destructive evaluation (NDE) techniques for quality control and life­remain assessment of TBCs. This paper overviews the governing principles and applications of the luminescence and the impedance examined in the light of residual stress, phase constituents and resistance (or capacitance) in TBC constituents including the thermally grown oxide (TGO) scale. Results from NDE by PSLS and EIS are discussed and related to the microstructural development during high temperature thermal cycling, examined by using a variety of microscopic techniques including focused ion beam (FIB) in­situ lift­out (INLO), transmission and scanning transmission electron microscopy (TEM and STEM).

• Preventive Nutrition and Food Science
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• v.10 no.2
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• pp.140-144
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• 2005

This study was carried out to establish methods for irradiation detection of irradiation in Korean wheat flour by pulsed photostimulated luminescence (PPSL) and viscometric methods. The photon counts of the irradiated Korean wheat flour measured by PPSL immediately after irradiation increased with increasing irradiation dose. The photon counts in the irradiated Korean wheat flour almost disappeared with lapse of time after storage in normal room conditions, but irradiation detection was still possible after 6 months in darkroom conditions. All irradiated samples indicated a decrease in viscosity with increasing stirring speeds (rpm) and irradiation doses. Irradiation at 1 kGy significantly decreased the viscosity. Consequently, these results suggest that the detection of irradiated Korean wheat powder is possible by both viscometric and PPSL methods.

• Proceedings of the Korean Nuclear Society Conference
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• 2003.05a
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• pp.365.2-365.2
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• 2003

• Proceedings of the Korean Nutrition Society Conference
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• 2001.05a
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• pp.202.2-202
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• 2001