• Korean Journal of Food Science and Technology
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• v.44 no.6
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• pp.673-679
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• 2012

Ten commercially available red pepper powders were investigated using photostimulated-luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) analyses to confirm their irradiation status. The application of PSL, TL, and ESR analyses was also confirmed by in-house irradiation. In PSL-based screening, all samples gave negative photon counts (<700 PCs). The PSL calibration dose (1 kGy) showed a low sensitivity of 4 samples, while the others provided reliable screening results. TL glow curves demonstrated maximum peaks after $250^{\circ}C$ for the 6 samples; however 4 samples gave complex TL glow curves with maximum peaks in the range of $185-260^{\circ}C$ (radiation-specific), which could be the effect of an irradiated component in low concentration as the TL ratios of all samples were <0.1. Radiation-specific ESR features were absent in the all commercial samples. Variable irradiation detection properties were found; where the TL analysis showed the possible presence of an irradiated component in 4 samples requiring further monitoring and investigation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.3
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• pp.123-128
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• 2004

Both photoluminescence and the long-phosphorescent properties for $SrAl_2O_4$ : Eu$^{+2}$, $Dy^{+3}$ phosphor powder synthesized by the solid phase reaction were investigated as a function of $B_2O_3$ composition (0-10 wt%). The highest emission wavelength (520nm) of photoluminescence spectra was not affected by $B_2O_3$concentration. The highest emission intensity was obtained by the concentration of 3 wt% $B_2O_3$.After the removal of the Xenon lamp excitation (360nm), also, the excellent long-phosphorescent property of the phosphors was obtained by the concentration of 3 wt% $B_2O_3$ although the decay times for all phosphors decreased exponentially.

• Journal of the Korean Vacuum Society
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• v.20 no.2
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• pp.114-126
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• 2011

The light propagation along a long positive column has been observed in a cold cathode fluorescent lamp. The optical signals are observed with the DC and AC voltage power during lamp operation. The light propagating is observed in the operation with the DC-rippled voltage as well as the AC-voltage. The optical signals propagate from the high voltage side to the ground. These signals show two kinds of features according to the before and after Townsend breakdown. At the dark current before Townsend breakdown, the optical intensity is damped and the propagation velocity is $10^4{\sim}10^5m/s$. At the high current of normal glow after Townsend breakdown, the propagation velocity is 1$10^5{\sim}10^6m/s$ without damping.

• Journal of the Korean institute of surface engineering
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• v.56 no.2
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• pp.152-159
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• 2023

The night visibility of pavement is being considered as a global issue in the field of traffic safety. Although the spreading glass beads on the lane paints has been mainly used to secure night-visibility by utilizing the effect of retroreflection, obvious shortcoming of this method is that retroflection does not occur in the range where the headlights do not reach the glass beads. The use of functional paints including phosphorescent constituents could be a solution for overcoming fore-mentioned problem. SrAl₂O₄ based chemicals have not only good phosphorescent property, but also are chemically stable compared to existing ZnS based materials. However, this chemicals also need the improvement due to slightly reduced luminous effect in time. Herein, we developed novel paints showing enhanced phosphorescent properties by putting rare earth elements such as Eu, Dy and Y into SrAl₂O₄. These prepared phosphorescent pigments have displayed improved properties in terms of durability and long afterglow. For instance, the property of afterglow has been persisted after 5 hours with luminace of 20.6 mcd/m².

• Food Science and Preservation
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• v.18 no.3
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• pp.294-301
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• 2011

The aim of this study was to investigate the changes in identification markers of irradiated foods after treatment of the full-overlapped gravitational field energy (FGFE). Wheat and soybean samples were irradiated at 0-5 kGy of Co-60 gamma energy, and analyzed for photostimulated and thermo luminescence characteristics (PSL and TL) and sprouting rate at 0 and 6th month after FGFE treatment. As a screening method for irradiated samples, PSL photon counts (PCs) for the non-irradiated samples appeared negative (<700 PCs), while irradiated samples gave positive (>5,000 PCs). But FGFE-treated irradiated samples appeared intermediate (700-5,000 PCs), showing decreased PCs during storage. The TL analysis on irradiated samples exhibited glow curve peaks in range of $150-200^{\circ}C$ and TL ratio ($TL_1/TL_2$) was also >0.1. Therefore, identification of irradiated samples was possible using thermoluminescence. But the glow curve range of FGFE-treated irradiated samples shifted from $150-200^{\circ}C$ to $180-230^{\circ}C$ and TL intensity was decreased 37-60% resulting from FGFE treatment. After 6 months of storage, all the samples showed a decrease in TL intensity, but identification was still possible. The sprouting rate of irradiated samples decreased by about 72%, whereas that of FGFE-treated irradiated samples showed by about 85%, as compared to non-irradiated samples. More detailed study is required to investigate sprouting phenomena for FGFE-treated samples.

• Journal of Nutrition and Health
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• v.9 no.3
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• pp.18-25
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• 1976

To explain the change of the pungent principles of red pepper, capsaicin, during storage, the relation between infecting mold and capsaicin was studied. Results obtained were summarized as follows; 1. Superior strains which showed good growth and high decomposition activity in their culture broths, Aspergillus oryzae and Aspergillus sp. KF-7 were obtained from the contaminated red pepper fruits. 2. The weight of dry matter was increased at low concentration of capsaicin $(2{\sim}3{\mu}g/ml)$ but it was decreased at high concentration. 3. The residual capsaicin in the culture medium was reduced as half as such after 1 week, and almost disappeared after 2 weeks. At $30^{\circ}C$ and $pH\;7{\sim}9$ of culturing condition, the amounts of reducing capsaicin reached to the maximum. 4. At ground red pepper fruits as culture medium, Aspergillus sp. KF-7 could not glow at all, but Aspergillus oryzae showed good growth at 13% of moisture contents and the residual of capsaicin of red pepper fruits after 40days of cultivation time was 45%. 5. At ground red pepper fruits seed as culture medium, Aspergillus oryzae and Aspergillus sp. KF-7 showed good growth, and the residual of capsaicin after 4 weeks of cultivation time was 55% and 38% respectively.

• Journal of Energy Engineering
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• v.25 no.1
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• pp.76-85
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• 2016

This study introduces the system layout and control strategy necessary to start and operate a fuel processor in a wide range of temperatures where a gasoline was selected as the fuel of fuel processor considering logistic support of Korea Army. The autothermal reformig(ATR) catalyst is heated to light-off temperature by combustion method in the initial stage. In order to ignite the gasoline and air mixture stably, the glow plug is installed after ATR catalyst. When the catalyst is increased to light-off temperature, the reformer is operated from initiation to steady state conditions as follows: Partial oxidation(POX) mode, partial ATR mode, full ATR mode. Finally the start-up and control strategy is validated by the operational test of gasoline fuel processor at low and room temperature. As a result the gasoline fuel processor is able to start-up within 40 min and to produce the reformate gas which has 37 ~ 42 vol.%(dry basis) of $H_2$ and 0.3 vol.% of CO.

• Journal of the Korean Ceramic Society
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• v.42 no.9 s.280
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• pp.624-630
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• 2005

To investigate the possibility of the $ZrO_2$ buffer layer as the insulator for the Metal-Ferroelectric-Insulator-semiconductor (MFIS) structure, $ZrO_2$ and $SrBi_2Ta_2O_9$ (SBT) thin films were deposited on the P-type Si(111) wafer by the R.F. magnetron-sputtering method. According to the process with and without the post-annealing of the $ZrO_2$ buffer layer and SBT thin film, the diffusion amount of Sr, Bi, Ta elements show slight difference through the Glow Discharge Spectrometer (GDS) analysis. From X-ray Photoelectron Spectroscopy (XPS) results, we could confirm that the post-annealing process affects the chemical binding condition of the interface between the $ZrO_2$ thin film and the Si substrate. Compared to the MFIS structure without the post-annealing of the $ZrO_2$ buffer layer, memory window value of MFlS structure with post-annealing of the $ZrO_2$ buffer layer were considerably improved. The window memory of the Pt/SBT (260 nm, $800^{\circ}C)/ZrO_2$ (20 nm) structure increases from 0.75 to 2.2 V under the applied voltage of 9 V after post-annealing.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.2
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• pp.81-89
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• 2006

The purpose of this study was to evaluate the applicability of small RC(radio controlled) helicopter and single lens reflect camera as SFAP(Small Format Aerial Photography) aquisition system to monitor the vegetation coverage of wetland. The system used to take pictures of small artificial wetland were a common optical camera(Nikon F80 with manual lens whose focal length was 28mm) attached to the bottom of a RC helicopter with a 50 cubic inch size glow engine. Three hundreds pictures were taken at the altitude of 50m above the ground, from 23rd June to 7th September 2005. Four from the images were selected and scanned to digital images whose dimension were 2048${\times}$1357 pixels. Those images were processed and rectified with GCP(Ground Control Poins) and digital map, and then classified by the supervised- classification module of image processing program PG-steamer Version 2.2. The major findings were as follows ; 1. The final images processed had very high spatial resolution so that the objects bigger than 30mm like lotus(Nelumbo nucifera), rock and deck were easily identified. 2. The dominant plants of the monitoring site were Monochoria ragianlis, Typha latifolia, Beckmannia syzigachne etc. Because those species have narrow and long leaves and form irregular biomass, the individuals were hardly identifiable, but the distribution of population were easily identifiable depending on the color difference. 3. The area covered by vegetation was rapidly increased during the first month of monitoring. At the beginning of the monitoring 23th June 2005, The rate of area covered by vegetation were only 34%, but after 27 and 60 days it increased to 74%, and the 86% respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.11
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• pp.1559-1564
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• 2012

Raisins (Thailand), dried mangos (Philippines), and dried figs (Iran) were gamma-irradiated (0~5 kGy), and their quality and detection characteristics were investigated. Microbiological characteristics were at safe levels when samples were irradiated at higher than 3 kGy. In color change after irradiation, dried mangoes were the most sensitive. Photostimulated luminescence (PSL) measurement was not applicable to dried fruits, showing negative or intermediate values for the irradiated samples. Thermoluminescence (TL) measurement was good for dried figs, exhibiting a glow curve in range of $150{\sim}200^{\circ}C$, where the signal intensity was dependent on the irradiation dose. Electron spin resonance (ESR) measurement was suitable for raisins and dried mangos, resulting in dose-dependent radiation-induced sugar radical signals.