• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.128-136
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• 2015

This study investigated the effects of low-dose electron beam irradiation treatment on physicochemical and sensorial properties of imported navel oranges during storage at $3^{\circ}C$ for 45 days. The samples were irradiated at doses of 0.2, 0.4, 0.6, 0.8, and 1.0 kGy, and changes in their color values, hardness, Brix/acid ratio, total sugar contents, reducing sugar contents, vitamin C contents, and sensory evaluation were investigated. There were no significant differences between non-irradiated and irradiated samples in terms of color values, Brix/acid ratio, total sugar contents, total reducing sugar contents, and vitamin C contents. Hardness of irradiated sample at 1 kGy decreased significantly in the early storage period, but the difference between non-irradiated and irradiated samples decreased again at the end of storage. For the sensory evaluation, scores of color, sweetness, flavor, and overall acceptability decreased as irradiation dose and storage period increased. Samples irradiated at over 0.8 kGy showed low preference in all scores except color. These results suggest that electron beam irradiation below 0.6 kGy does not affect physicochemical and sensory properties; thus, electron beam irradiation up to 0.6 kGy in imported navel oranges is optimum for minimizing quality changes and disinfestation treatment simultaneously.

• Journal of Korean Philosophical Society
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• v.117
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• pp.85-111
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• 2011

Topics with which chis paper deals are as following; (1)Zizek's interpretation of Rothko's painting, (2)Lacan's gaze and picture, (3)the real as object a, (4)primal jouissance and death-drive, (5)a new identity of man-emptiness in Zizek, (6) existential level and existential conflict, (7)a variety of meanings of emptiness, (8)transpecsonal drive and meditation, (9) the different Real-Emptiness, (10)Rochko's painting and transpersonal drive.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.111-114
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• 2005

This study is about the cosmeceutical products using enzyme induced bio-conversion system. In general, ascorbic acid (AA) has the higher reducing activity and can be used for various purpose in the cosmetics. But it is very unstable in the aqueous system and difficult to maintain its stability in the cosmetics product. 2-O-$\alpha$-D-Glucopyranosyl-L-ascorbic acid (AA2G) is the stabilized form of AA and showed the less whitening activity than AA. In this study, we developed bio-conversion system improving the stability and efficacy of AA2G and AA, respectively. In this system, AA2G (over $80\%$) can be converted to AA and glucose within 30 min. The converted product showed higher anti-tyrosinase activity like AA (AA2G showed no anti tyrosinase activity) and depigmenting activity in the artificial tanning test. From these results, we could conclude this system is a brand new method to increase the activity of AA and maintain its stability.

• Food Science and Preservation
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• v.24 no.3
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• pp.421-430
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• 2017

This study was conducted to investigate the effect of Lentinus edodes powder on the quality characteristics and antioxidant of rice cookies. The cookies for this experiment was made by 3 main ingredients including rice powder, flour, Lentinus edodes powder. The proportion of rice powder was fixed to 50% for the total amount of ingredients. The amount of reminded 2 ingredients (flour and Lentinus edodes powder) were varied. The amount of flour was decreased up to 38%, and the addition of Lentinus edodes powder was increased to 4%, 8% and 12%. Density of the dough, hardness, total polyphenol content, DPPH free radical scavenging activity, and reducing power increased with increasing Lentinus edodes powder content. Moisture content, pH of the dough, spread factor, loss rate, leavening rate, and L values of the cookies were decreased with increasing Lentinus edodes powder content. The result of consumer acceptance test revealed that there were no significant differences in smell, taste and overall acceptability, while the preference of color decreased as the amount of Lentinus edodes powder increased. To sum up, the cookies with 12% Lentinus edodes powder can produced the best results in terms of quality and antioxidant potential.

• Korean Chemical Engineering Research
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• v.56 no.6
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• pp.819-825
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• 2018

Porous nanofibers comprising hollow ${\alpha}-Fe_2O_3$ nanospheres were prepared by applying both template method and Kirkendall diffusion effect to electrospinning process. During heat-treatment processes, the solid Fe nano-metals formed by initial heat-treatment in the carbon matrix were converted into the hollow structured ${\alpha}-Fe_2O_3$ nanospheres. In particular, PS nanobeads added in the spinning solution were decomposed and formed numerous channels in the composite, which served as a good pathway for Kirkendall diffusion gas. The resulting porous nanofibers comprising hollow ${\alpha}-Fe_2O_3$ nanospheres were applied as an anode material for lithium-ion batteries. The discharge capacities of the nanofibers for the 30th cycle at a high current density of $1.0A\;g^{-1}$ was $776mA\;h\;g^{-1}$. The good lithium ion storage property was attributed to the synergetic effects of the hollow ${\alpha}-Fe_2O_3$ nanospheres and the interstitial nanovoids between the nanospheres. The synthetic method proposed in this study could be applied to the preparation of porous nanofibers comprising hollow nanospheres with various composition for various applications, including energy storage.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.3
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• pp.279-298
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• 2019

This study comprehensively addresses recent progress at KAERI in waste treatment technology to cope with waste produced by pyroprocessing, which is used to effectively manage spent fuel. The goal of pyroprocessing waste treatment is to reduce final waste volume, fabricate durable waste forms suitable for disposal, and ensure safe packaging and storage. KAERI employs grouping of fission products recovered from process streams and immobilizes them in separate waste forms, resulting in product recycling and waste volume minimization. Novel aspects of KAERI approach include high temperature treatment of spent oxide fuel for the fabrication of feed materials for the oxide reduction process, and fission product concentration or separation from LiCl or LiCl-KCl salt streams for salt recycling and higher fission-product loading in the final waste form. Based on laboratory-scale tests, an engineering-scale process test is in progress to obtain information on the performance of scale-up processes at KAERI.

• Clean Technology
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• v.27 no.1
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• pp.61-68
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• 2021

Selective catalytic reduction (SCR) is widely used as a method of removing nitrogen oxide in large-capacity thermal power generation systems. Uniform mixing of the injected ammonia and the inlet flue gas is very important to the performance of the denitrification reduction process in the catalyst bed. In the present study, a computational analysis technique was applied to the ammonia injection system design process of a denitrification facility. The applied model is the denitrification facility of an 800 MW class coal-fired power plant currently in operation. The flow field to be solved ranges from the inlet of the ammonia injection system to the end of the catalyst bed. The flow was analyzed in the two-dimensional domain assuming incompressible. The steady-state turbulent flow was solved with the commercial software named ANSYS-Fluent. The nozzle arrangement gap and injection flow rate in the ammonia injection system were chosen as the design parameters. A total of four (4) cases were simulated and compared. The root mean square of the NH3/NO molar ratio at the inlet of the catalyst layer was chosen as the optimization parameter and the design of the experiment was used as the base of the optimization algorithm. The case where the nozzle pitch and flow rate were adjusted at the same time was the best in terms of flow uniformity.

• Analytical Science and Technology
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• v.35 no.6
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• pp.256-266
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• 2022

It is important to determine the concentration of long-lived radionuclides (e.g., ¹²⁹I) in nuclear waste to ensure safety when handling it. To analyze nuclides in a solid sample (e.g., concrete and soil), it is essential to effectively separate and purify the nuclides of interest in the sample. This study reports the comprehensive efforts made to validate the analytical procedure for ¹²⁹I detection in solid samples, using a high-temperature combustion furnace. ¹²⁹I volatilized from the sample collected in 0.01 M HNO₃ solution with a reducing agent (e.g., NaHSO₃) and was rapidly measured by ICP-MS. Analytical conditions, such as pyrolysis temperature and types of mobile phase gas, catalyst, and trapping solution, were optimized to obtain a high recovery rate of spiked ¹²⁹I. Finally, the optimized method was applied for the simultaneous analysis of other volatile radionuclides, such as ³H and ¹⁴C. The performance test results for the optimized method confirmed that the LSC (for ³H and ¹⁴C) and ICP-MS (for ¹²⁹I) measurements, with the separation of volatile nuclides using a high-temperature combustion furnace, were reliable.

• Food Science and Preservation
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• v.30 no.2
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• pp.300-310
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• 2023

This study was carried out to investigate the effect of the extraction conditions for persimmon (Diospyros kaki Thunb.) leaf tea (PLT) on its color quality and antioxidant properties. The amount of persimmon leaf (PL) powder and pH influenced the PLT's color and antioxidant capacity. As the amount of PL powder in tea increased, lightness decreased while yellowness increased. The PLT with the highest amount of PL (10 mg/mL) exhibited the highest 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity and ferric reducing antioxidant power (FRAP). In addition, the PLT with the highest PL showed the highest total polyphenol and flavonoid contents. Subsequently, PLT was prepared using 10 mg/mL PL powder under varying pH conditions. As pH increased from 4 to 7, lightness decreased while redness and yellowness increased. Antioxidant capacity was determined using 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and FRAP assay showed that lower pH exhibited higher antioxidant capacity. The PLT extracted under the lowest pH of 4 showed higher polyphenol and flavonoid contents than that extracted under higher pH conditions. Overall, PLT extraction using a solvent with pH 4.0 showed better antioxidant activities and higher amounts of polyphenolic compounds. Simultaneously, lesser lightness, redness, and yellowness were detected in PLT extracted under pH 4 conditions. In conclusion, to acquire a better functional health benefit in terms of antioxidant capacity, preparing PLT under pH 4 conditions is suggested.

• Journal of the Korea Organic Resources Recycling Association
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• v.32 no.1
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• pp.39-47
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• 2024

In this study, LiDAR-detective black material is synthesized by recycling silicon sludge (SS) that is generated from semiconductor manufacturing process, and its recognition is confirmed using two types of LiDAR sensors (MEMS and Rotating LiDAR). In detail, metal impurities on the surface of SS is removed, followed by coating of titanium dioxide (TiO₂) and subsequent chemical reduction to obtain SS-derived black TiO₂ (SS/bTiO₂) material. As-prepared SS/bTiO₂ is mixed with transparent paint to prepare hydrophilic black paints and applied to a glass substrate using a spray gun. SS/bTiO₂-based paint shows similar blackness (L^*=15.7) compared to commercial carbon black-based paint, and remarkable NIR reflectance (26.5R%, 905nm). Furthermore, MEMS and Rotating LiDAR have successfully detected the SS/bTiO₂-based paint. This is attributed to the occurrence of high reflection of light at the interface between the black TiO₂ and the silicon sludge according to the Fresnel's reflection principle. Hence, the new application field to effectively recycle silicon sludge generated in the semiconductor manufacturing process has been presented.