• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1569-1574
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• 2011

In this study, the identification of the irradiated seafood cooking drips from Hizikia fusiformis, Enteroctopus dofleini and Thunnus thynnus was conducted. The physical detection methods used included photo-stimulated luminescence (PSL) and thermoluminescence (TL), and the chemical detection methods were hydrocarbons analysis. In the PSL study, all seafood cooking drip samples showed 260~510 photon counts; thus, the PSL method could not be used for the detection of irradiated seafood cooking drips. The TL method could be used for the detection of irradiated H. fusiformis and E. dofleini cooking drips. In both cooking drips, the shapes of the glow curves indicated a specific peak at 150$^{\circ}C$~250$^{\circ}C$, which made it possible to identify the irradiated samples. The hydrocarbons derived by gamma irradiation of T. thynnus cooking drip were not detected due to low concentration and inconsistent content of fatty acids in the untreated T. thynnus cooking drip.

• Journal of Food Hygiene and Safety
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• v.16 no.1
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• pp.82-87
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• 2001

A study was performed to establish detection methods by viscometric and pulsed photostimulated luminescence (PPSL) methods for irradiated com powder. Viscosity was determined using a Brookfield DV-rotation viscometer at 3$0^{\circ}C$ and operated at 30, 60, 90, 120, 150, 180, and 210 rpm. All irradiated samples showed a decrease in Viscosity with increasing stirring speeds (rpm) and irradiation doses. Treatments at 1~3 kGy significantly decreased the viscosity. The photon counts of irradiated corn powder were measured by PPSL immediately after irradiation and exhibited an increase with increasing irradiation dose. The photon counts of irradiated com powder almost disappeared with lapse of time in room conditions, but detection of irradiation was still possible after one month at darkroom conditions. Consequently, these results suggest that the detection of irradiated com powder is possible by both viscometric and PPSL methods.

• Journal of Radiation Industry
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• v.6 no.2
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• pp.119-123
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• 2012

The detection properties of gamma-irradiated (0~10 kGy) dried seaweed, dried shrimp, and seasoned dried filefish were investigated by photo-stimulated luminescence (PSL) and electron spin resonance (ESR). PSL could be used as a detection method on irradiated dried seaweed and dried shrimp as they showed photon counts greater than 5,000 counts/60 s (positive) in the irradiated samples with doses above l kGy. However, PSL could not be applied to detect irradiated seasoned dried filefish, because gamma-irradiated sample at 10 kGy even yielded photon counts less than 700 counts/60 s (negative). The ESR spectroscopy for only dried shrimp revealed specific signals derived from free radicals captured in the shell of shrimp. As a result, it is considered that PSL or ESR methods for detection of gamma-irradiated dried shrimp and only PSL can be used to detect gamma-irradiated seaweed. Furthermore, it is considered that hydrocarbon analysis of seasoned dried filefish containing fat by GC/MS and Thermo Luminance (TL) analysis of dried seaweed should be studied for detection of irradiation.

• 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.

• Journal of Radiation Industry
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• v.2 no.1
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• pp.27-34
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• 2008

Photostimulated luminescence (PSL), electron spin resonance (ESR) and thermoluminescence (TL) analyses were conducted to detect whether 258 kinds of extracted and powdered forms food additives were irradiated or not. In a view of the PSL results, 9 kinds of the extracted and powdered samples (3.2%) showed over 5,000 photon counts $(60sec)^{-1}$ and these samples were judged to be irradiation-positive. Thirty nine kinds of the samples (15.6%) yielded 700~5,000 photon counts $(60sec)^{-1}$ and these samples were grouped into irradiation-potential, while the samples showed below 700 photon counts $(60sec)^{-1}$ sec were judged to be irradiation-negative. TL glow curves for minerals separated from 5 samples were detected at $150^{\circ}C$ with high intensity. However, TL analysis did not apply to other irradiation-positive and irradiation-potential samples because the minerals for TL detection were not separated from the samples. ESR measurements for irradiation-positive and irradiation-potential samples, judged by PSL detection, showed no specific signals to irradiation. The results indicated that PSL could be applied to identify irradiation treatment of extracted and powdered food additives, while TL was optional and ESR was not suitable for detection extracted and powdered food additives.

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.51-52
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• 2006

• Journal of the Korean Chemical Society
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• v.36 no.6
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• pp.832-839
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• 1992

Lead has been determined by Resonance Ionization Mass Spectrometry (RIMS) through one-color-two-photon ionization, two-color-two-photon ionization and three-color-three-photon ionization in a vacuum chamber equipped with Time-of-Flight(TOF) mass spectrometer. In all cases, the first excited state chosen was 6p7s($^3P_1$) state and the transition was at 283.3 nm in wavelength from the ground state. By using various concentrations of lead standard solutions, the calibration curve is obtained in the range of 0.1 ${\mu}g$ to 1.0 pg in both ionization schemes. The detection limit was estimated as 20 pg for the two-color ionization, while 10 pg for the three-color ionization experiment.

• Current Optics and Photonics
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• v.6 no.2
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• pp.171-182
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• 2022

A single-photon laser and mid-wave infrared (MWIR) common aperture optical system was designed and developed to detect and range a long-distance civil aviation aircraft. The secondary mirror of the Ritchey-Chretien (R-C) optical system was chosen as a dichroic lens to realize the design of a common aperture system for the laser and MWIR. Point spread function (PSF) ellipticity was introduced to evaluate the coupling efficiency of the laser receiving system. A small aperture stop and narrow filter were set in the secondary image plane and an afocal light path of the laser system, respectively, and the stray light suppression ability of the small aperture stop was verified by modeling and simulation. With high-precision manufacturing technology by single point diamond turning (SPDT) and a high-efficiency dichroic coating, the laser/MWIR common aperture optical system with a 𝜑300 mm aluminum alloy mirror obtained images of buildings at a distance of 5 km with great quality. A civil aviation aircraft detection experiment was conducted. The results show that the common aperture system could detect and track long-distance civil aviation aircraft effectively, and the coverage was more than 450 km (signal-to-noise ratio = 6.3). It satisfied the application requirements for earlier warning and ranging of long-range targets in the area of aviation, aerospace and ground detection systems.

• Preventive Nutrition and Food Science
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• v.7 no.2
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• pp.195-200
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• 2002

Changes in accumulated pulsed photostimulated luminescene (PPSL) signals were observed after storage, which affected the ability to detect irradiation in black and white peppers. The PPSL curves were accumulated linearly during the 120 s measurement times, and PPSL signals increased according to irradiation doses. Threshold levels of black and white peppers were below 557$\pm$220 and 503$\pm$92 photon counts in 60 s, and below 679$\pm$351 and 812 $\pm$ 648 photon counts in 120 s, respectively. The PPSL signals of black and white peppers linearly increased with irradiation dose up to 5 kGy, but very little from 5~10 kCy. The accumulated PPSL signals of irradiated black and white peppers had higher decay rates when stored in normal room conditions than in a darkroom Detection of irradiation was possible for up to 12 months after irradiation, if the samples were stored in a darkroom.

• Nuclear Engineering and Technology
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• v.32 no.5
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• pp.446-456
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• 2000

Laser induced photoacoustic, fluorescence, and photon correlation spectroscopies were applied to the chemical characterization of radionuclides in connection with the radiowaste treatment and disposal. Their measuring principles and systems were briefly described together with their advantages over conventional spectroscopies. Also, other applications of lasers are introduced. Laser induced photoacoustic spectra were measured for a P $r^{3+}$ solution with a very low molar absorptivity. The detection sensitivity was 4.3 $\times$10$^{-5}$ c $m^{1}$ and was 100 times better than that of a UV/VIS spectrophotometer. The Eu(III) excitation spectra($^{7}$ $F_{0}$ longrightarrow $^{5}$ $D_{0}$ transition) were measured for Eu(III)-phthalate complexes using laser fluorescence spectroscopy, showing that only two species, 1:1 and 1:2 complexes, are present in the Eu(III)-phthalic acid system. The size and size distribution for colloidal humic acids and Eu(III)-humate colloids was determined using photon correlation spectroscopy. The presence of Eu(III) enhanced the aggregation of humic acids.s.