• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1114-1117
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• 2005

The effects of far-infrared (FIR) irradiation and heat treatment on the antioxidant activity of extracts from peanut shells was evaluated. Peanut shells were placed in pyrex petri dishes (8.0cm diameter) and irradiated at $150^{\circ}C$ for 5, 10, 15, 20, 40 or 60min with a FIR heater. After FIR irradiation or simple heat treatment at same conditions, methanol extracts of peanut shells were prepared and total phenol contents (TPC), radical scavenging activities (RSA) and reducing powers of the extracts were determined. The antioxidant activities of the extracts increased as the time of heating or FIR-irradiation increased. When peanut shells were FIR­irradiated at $150^{\circ}C$ for 5 min, the values of TPC, RSA, and reducing power of the extracts increased from 40.17mg/mL to 42.30mg/mL, $67.7\%\;to\;76.3\%$, and 0.569 to 0.639, respectively, compared to the untreated controls. Simple heat treatment of peanut shell under the same conditions $(150^{\circ}C\;for\;5min)$ also increased the TPC, RSA, and reducing power of the extracts from 40.17mg/mL to 43.52mg/mL, 67.7\%\;to\;79.3\%$ and from 0.569 to 0.623, respectively. The results indicate that appropriate FIR-irradiation or heat treatment on peanut shells could increase the antioxidant activities of methanolic extracts.

• Korean Journal of Materials Research
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• v.13 no.7
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• pp.409-414
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• 2003

The room-temperature operating semiconductor GaMnN is known to be improved in its magnetic property when a highly conductive precipitate $Mn_3$GaN exists. Therefore, it is useful to investigate the behavior of the precipitate through heat treatments for further improvement of its magnetic property. Furthermore, neutron irradiation may further influence the behavior of the precipitates, and consequently, their effects on the magnetization. With the heat treatment, $Mn_3$GaN decomposed and a new phase of $Mn_3$Ga has generated. The kinetics was accelerated by neutron irradiation, which might generate defects that can help the decomposition of N and/or the formation of $Mn_3$Ga. The increase and decrease of the magnetization of the heat-treated GaMnN thin films were explained consistently by the behavior of the precipitates.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.400-403
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• 2005

The effect of far-infrared (FIR) irradiation and heat treatment on the antioxidant activity of extracts from defatted soybean meal (DSM) was evaluated. DSM were placed in pyrex petri dishes (8.0 cm diameter) and irradiated at $150^{\circ}C$ for 5, 10, 15, 20, 40 or 60 min with a FIR heater or simple heater. After FIR irradiation or simple heat treatment at same conditions, methanol extracts of DSM were prepared and total phenol contents (TPC), radical scavenging activity (RSA) and reducing power of the extracts were determined. The antioxidant activities of the extracts increased as the time of heating or FIR-irradiation increased. When DSM were FIR-irradiated at $150^{\circ}C$ for 15 min, the values of TPC, RSA, and reducing power of the extracts increased from 31.62 mg/ml to 57.51 mg/ml, 11.6% to 53.1%, and 0.068 to 0.147, respectively, compared to the untreated controls. Simple heat treatment of DSM under the same conditions ($150^{\circ}C$ for 15 min) also increased the TPC, RSA, and reducing power of the extracts from to 58.04 mg/ml, 65.2% and 0.160, respectively. The results indicated that appropriate FIR-irradiation or heat treatment on DSM increased the antioxidant activities of methanolic extracts.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.80-99
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• 2023

This paper presents the results of investigating the change in welding residual stresses of the core shroud, which is one of subcomponents in reactor vessel internals, performing finite element analysis. First, the welding residual stresses of the core shroud were calculated by applying the heat conduction based lumped pass technique and finite element elastic-plastic stress analysis. Second, the temperature distribution of the core shroud during the normal operation was calculated by performing finite element temperature analysis considering gamma heating. Third, through the finite element viscoelastic-plastic stress analysis using the calculated temperature distribution and setting the calculated residual stresses as the initial stress state, the variation of the welding residual stresses was derived according to repeating the normal operation. In the viscoelastic-plastic stress analysis, the effects of neutron irradiation on mechanical properties during the cyclic normal operations were considered by using the previously developed user subroutines for the irradiation agings such as irradiation hardening/embrittlement, irradiation-induced creep, and void swelling. Finally, the effect of neutron irradiation on the welding residual stresses was analysed for each irradiation aging. As a result, it is found that as the normal operation is repeated, the welding residual stresses decrease and show insignificant magnitudes after the 10^th refueling cycle. In addition, the irradiation-induced creep/void swelling has significant mitigation effect on the residual stresses whereas the irradiation hardening/embrittlement has no effect on those.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.2
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• pp.43-46
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• 2000

Nd:YAG laser of 355 nm wavelength, which amounts to 3.5 eV, produced by a harmonic generator was used to create Ag metallic particles as seeds for nucleation in photosensitive glass containing $Ag^+$ and $Ce^{3+}$ . The pulse widths and frequency of the laser were 8ns and 10 Hz, respectively. For crystalline growth, heat-treatment following laser irradiation was carried out at $570^{\circ}C$ for 1h. Then, the $LiAlSi_3O^8$ crystal phase appeared in the laser irradiated lithium aluminum silicate glass. We present the effect of laser-induced nucleation compared with spontaneous nucleation by heat treatment fur crystallization in the glass.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2000.04a
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• pp.112-117
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• 2000

Nd:YAG laser of 355nm wavelength, which amounts to 3.5eV, produced by a harmonic generator was used to create Ag metallic particles as seeds for nucleation in photosensitive glass containing Ag+ and Ce3+. The pulse widths and frequency of the laser were 8ns and 10Hz, respectively. For crystalline growth, heat-treatment following laser irradiation was carried out at $570^{\circ}C$ fur 1h. Then, the LiAlSi3O8. crystal phase appeared in the laser irradiated lithium aluminum silicate glass. We present the effect of laser-induced nucleation compared with spontaneous nucleation by heat treatment for crystallization in the glass.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.4
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• pp.405-412
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• 2004

During the irradiation tests of material and fuel rod, all components of the cylindrical structure with multiple holes act like heat sources due to high gamma heat and fission heat. The objective of this study is to formulate the general solution for the temperature distribution to estimate the thermal integrity of structure during irradiation tests. For the temperature distribution analysis, the two-dimensional heat conduction theory is used. The unmerical analysis is performed by the commercial finite element analysis code, ANSYS 6.1. If the cylindrical structure with hole number would not exceed three holes, the analysis results and finite element results are good agreement together. For the structure with four holes, the discrepancy between FE results and analysis results of the structural temperature distribution is increased.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.1
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• pp.54-58
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• 2017

The effect of low temperature ($250^{\circ}C$) heat treatment after electron irradiation (irradiation time = 30, 180, 300s) on the chemical bonding and electrical properties of ZnO thin films prepared using a sol-gel process were examined. XPS (X-ray photoelectron spectroscopy) analysis showed that the electron beam irradiation decreased the concentration of M-O bonding and increased the OH bonding. As a result of the electron beam irradiation, the carrier concentration of ZnO films increased. The on/off ratio was maintained at ${\sim}10^5$ and the $V_{TH}$ values shifted negatively from 11 to 1 V. As the irradiation time increased from 0 to 300s, the calculated S. S. (subthreshold swing) of ZnO TFTs increased from 1.03 to 3.69 V/decade. These values are superior when compared the sample heat-treated at $400^{\circ}C$ representing on/off ratio of ${\sim}10^2$ and S. S. value of 10.40 V/decade.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.90-90
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• 2010

We investigated the modification of optical response properties of titanium dioxide (TiO2) coatings on the ceramic water-purification filters by using ultraviolet-visible absorption spectroscopy and X-ray diffraction. The TiO2 coatings were prepared on ceramic substrate by e-beam evaporation method. These amorphous TiO2 were turned into anatase phase by heat treatment at $700^{\circ}C$ for 2 hours. The doping of N atoms into the TiO2 coatings was done by using 70KeV of N＋ ion implantation with the dose of $1.0{\times}1017$ ions/cm2, followed by post-irradiation heat treatment at $550^{\circ}C$ for 2 hours. Methylene blue test of TiO2 coatings to solar irradiation showed that the post-evaporation heated TiO2 was photocatalytic and N-doped TiO2 reacted to the visible part of solar irradiation.

• Journal of Welding and Joining
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• v.33 no.6
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• pp.60-66
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• 2015

Molten zone shape of pulse laser welding is affected by welding conditions such as beam power, beam speed, irradiation time, pulse frequency, etc. and is divided into conduction type and keyhole type. It is necessary to design heat source model for irradiation of laser beam in the pulse laser welding. Shape variables and the maximum energy density value of the heat source model are different depending on the molten zone shape. In this paper, pulse laser welding simulation for joining of cylindrical part and circular cover was carried out. The heat source model for pulse laser beam with circular path was applied to the heat input boundary condition, radiative and conductive heat transfer were considered for the thermal boundary condition. For each phase, thermal and mechanical properties according to temperature were also applied to analysis. Analytical results were in good agreement with the molten zone size of specimen under the same welding conditions. So, the reliability of the welding simulation was verified. Finally, the improvements for reducing residual deformation after cover welding could be reviewed analytically.