• Journal of the Korean Applied Science and Technology
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• v.29 no.2
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• pp.330-338
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• 2012

During 10 days germination of perilla seeds for sprouts preparation, the changes of proximate composition and antioxidant activities were monitored, and the inhibitory effect of sprouts extracts on perilla oil oxidation was also studied. The moisture content in seeds(2.9%) was increased to 9.2% in sprouts at 10 days while crude ash content wasn't significantly. The crude fat and protein contents were reduced from 46.8% and 20.7% in seeds to 18.2% and 18.3% in sprouts, respectively, but reducing sugar and fiber contents increased from 2.2% and 14.8% to 12.8% and 22.4%, respectively. Compared with perilla leaf, sprouts at 10 days contained more fat, carbohydrate, reducing sugar, and fiber while less moisture, ash, and protein. Antioxidant activities during germination were increased and reached to maximum at 8 days in which Trolox equivalent antioxidant capacity(TEAC) based on DPPH and ABTS radical scavenging were 133.1 and 136.8 Trolox eq. mmol/kg, respectively, and ferric ion reducing power(FRAP) was 399.3 Fe(II) eq. mmol/kg. Polyphenol content(19.2 g/kg) was maximum at this stage, too. Perilla leaf showed similar TEAC but higher FRAP than the sprouts. When methanol extract of sprouts at 8 days was added to perilla oil, the oil oxidation was delayed in dose dependent manner. The induction time for oxidation was extended about 2.8 times by adding 2.5%(w/w) extract, that is, from 1.67 hr(control) to 4.62 hr. This induction time corresponded to 38% level of that of perilla oil containing 2.5% BHT.

• Korean Journal of Materials Research
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• v.7 no.9
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• pp.781-788
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• 1997

Cu/EMC 계면 접착력에 미치는 산화의 규명하기 위해 리드프레임의 저온 산화에 대하여 조사하였다. 이전의 보고와 달리, 저온에서도 Cu$_{2}$O위에 CuO산화물이 형성되어 Cu/Cu$_{2}$O(NiO)/Cu(NiO)/air의 산화층 구조를 나타내었다. Cu/EMC 계면 접착력은 산화가 진행됨에 따라 산화 초기에 급격히 증가하다 최대값에 이르고, 이후의 계속적인 산화로 감소하는 양상을 보였다. 접착력은 산화 온도나 리드프레임의 종류보다 산화막의 두께에 밀접한 상관 관계를 나타내었다. 최대 계면 접착력이 얻어지는 산화막의 두께는 리드프레임의 종류보다 산화막의 두께에 밀접한 상관 관계를 나타내었다. 최대 계면 접착력이 얻어지는 산화막의 두께는 리드프레임의 종류와 무관하게 대략 20nm 와 30nm 사이에 존재하였다. 산화 초기의 접착력 증가는 산화로 인한 EMC에 대한 젖음성의 증가와 기계적 고착 효과의 증가에 기인하였다. 리드프레임과 EMC의 파괴 표면에 대한 AES, XPS 분석으로 부터, 산화막의 두께가 얇을 때에는 Cu$_{2}$O//CuO의 계면 파괴 + EMC 자체 파괴가 복합적으로 발생함을 알 수 있었다. 반면에 과도한 산화로 낮을 접착력을 나타내는 시편은 Cu/Cu$_{2}$/O 계면의 파괴를 나타냈다.

• Food Science and Preservation
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• v.14 no.4
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• pp.400-407
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• 2007

This study compared lipid oxidation and color stability of M. longissimus from five Korean native black barrows (66 kg average weight; KNP) and modern genotype barrows ($Landrace{\times}Yorkshire{\times}Duroc$, 112 kg average weight, MGP) during light exposure in a refrigerated shop display. The meat samples were aged at $1^{\circ}C$ for 5 days and either kept in the dark, or under light of flux 3,000 lux, at $4^{\circ}C$ for 7 days. The KNPs contained larger amounts of fat than did MGPs (p<0.05), but KNPs had lower $C_{14:0},\;Cl_{8:3},\;and\;C_{20:5}$ contents than did MGPs (p<0.05). The pH of KNP was lower than that of MGP, and increased more rapidly upon exposure to light. The TBARS assay showed that oxidized lipid levels increased more rapidly in KNP than in MGP, and this accumulation was accelerated by exposure to light. The KNP was always a darker red in color than was MGP, and the color deteriorated more rapidly in the light than in the dark. The sensory attributes of raw pork were reduced by exposure to light, but KNP showed higher sensory attributes than did MGP. Compared to the MGP, the KNP showed greater color stability under light, retained desired sensory attributes under light longer, but showed a lower lipid oxidation stability under light. Overall, light exposure accelerated lipid oxidation in and discoloration of pork.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2001.11a
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• pp.101-101
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• 2001

• Proceedings of the Materials Research Society of Korea Conference
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• 2008.05a
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• pp.39.2-39.2
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• 2008

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.241.1-241.1
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• 2013

최근 고집적화된 금속-산화막 반도체 metal oxide semiconductor (MOS) 소자는 크기가 점점 작아짐에 따라 얇은 산화막과 다양한 High-K 물질과 전극에 대하여 연구되고 있다. 이러한 소자의 열적 안정성과 균일성을 얻기 위해 다양한 열처리 방법이 사용되고 있으며, 일반적인 열처리 방법으로는 conventional thermal annealing (CTA)과 rapid thermal annealing (RTA)이 많이 이용되고 있다. 본 실험에서는 microwave radiation에 의한 열처리로 소자의 특성을 개선시킬 수 있다는 사실을 확인하였고, 상대적으로 $100^{\circ}C$ 이하의 저온에서도 공정이 이루어지기 때문에 열에 의한 소자 특성의 열화를 억제할 수 있으며, 또한 짧은 처리 시간 및 공정의 단순화로 비용을 효과적으로 절감할 수 있다. 본 실험에서는 metal-oxide-silicon (MOS) 구조의 capacitor를 제작한 다음, 기존의 CTA나 RTA 처리가 아닌 microwave radiation을 실시하여 MOS capacitor의 전기적인 특성에 미치는 microwave radiation 효과를 평가하였다. 본 실험은 p-type Si 기판에 wet oxidation으로 300 nm 성장된 SiO2 산화막 위에 titanium/aluminium (Ti/Al) 금속 전극을 E-beam evaporator로 형성하여 capacitance-voltage (C-V) 특성 및 current-voltage (I-V) 특성을 평가하였다. 그 결과, microwave 처리를 통해 flat band voltage와 hysteresis 등이 개선되는 것을 확인하였고, microwave radiation 파워와 처리 시간을 최적화하였다. 또한 일반적인 CTA 열처리 소자와 비교하여 유사한 전기적 특성을 확인하였다. 이와 같은 microwave radiation 처리는 매우 낮은 온도에서 공정이 이루어짐에도 불구하고 시료 내에서의 microwave 에너지의 흡수가 CTA나 RTA 공정에서의 열에너지 흡수보다 훨씬 효율적으로 이루어지며, 결과적으로 산화막과 실리콘 기판의 계면 특성 개선에 매우 효과적이라는 것을 나타낸다. 따라서, microwave radiation 처리는 향후 저온공정을 요구하는 nano-scale MOSFET의 제작 및 저온 공정이 필수적인 display 소자 제작의 해결책으로 기대한다.

• Clean Technology
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• v.16 no.4
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• pp.265-271
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• 2010

The deactivated diesel oxidation catalyst(DOC) was remanufactured by ultrasonic wave treatment with various solutions, followed by active component re-impregnation. The catalytic performance and surface properties of remanufactured DOC were studied at various remanufacturing conditions. The proper ultrasonic-wave cleaning time at various solutions and optimal re-impregnation amounts of active component for the best catalytic performance were investigated. The catalytic performance tests on the conversions of CO and THC(total hydrocarbon) were also carried out at various temperatures by catalytic reaction test unit using bypass gas from the diesel engine dynamo system. It was found that the catalytic performance of DOC remanufactured with the high-temperature air washing, ultrasonic wave cleaning at acidic/basic solutions and active component re-impregnation method was recovered to 90% level of its activity compared to that of the fresh DOC, which was caused by removing the deactivating materials from the surface of the DOC through the analyses of catalyst performance test and their characterization by Optical microscope, EDX, ICP, TGA, and porosimeter.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.241-249
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• 2000

In this study, UV-catalyzed $H_2O_2$ oxidation and $H_2O_2$ oxidation to remove contaminants from photo processing chemicals were investigated at various conditions. Photo processing chemicals contains high concentrations of organic compounds and has very low biodegradability. Hydrogen peroxide is subjected to gradual decomposition as metastable substance. In the process, short-lived and highly reactive hydroxyl radicals are formed. The decomposition can be significantly accelerated by use of appropriate catalyst, such as ultraviolet radiation. The experiments were conducted in a UV-free reflecting reactor in batch and a high-pressure mercury lamp was used as UV source. Mixing, cooling and ventilation of the reactor were operated during experiments. In $UV/H_2O_2$ oxidation and $H_2O_2$ oxidation, the removal efficiencies of $COD_{Cr}$, TOC and chromaticity increased with the increase of $H_2O_2$ dosage and were higher in the controlled pH condition of 3 than in original pH condition of 8. In $UV/H_2O_2$ oxidation under the optimum condition of pH 8 and 1.3 stoichiometric $H_2O_2$ dosage, the removal efficiencies of $COD_{Cr}$, TOC and chromaticity were 47.5%, 75.0% and 91.5% respectively and $BOD/COD_{Cr}$ ratio was significantly increased from 0.04 to 0.21.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.1
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• pp.57-63
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• 2013

A combined process consisted of a biofilm reactor and a continuously stirred-tank reactor (CSTR) was investigated for highly loaded ammonium wastewater treatment via nitrite accumulation. To enhance ammonium oxidizing bacteria over nitrite oxidizing bacteria on the surface of carriers, the biofilm reactor was operated at temperature of $35^{\circ}C$ for more than three months but the influent ammonium (500 mg-N/L) was partially oxidized to nitrite (240 mg-N/L). As pH was increased from 7.5 to 8.0, nitrite accumulation was fully achieved due to the inhibition of nitrite oxidizing bacteria under high free ammonia concentration. The biofilm reactor performance was severely deteriorated at the hydraulic retention time of 12 hr, at which incomplete nitrification of ammonia was observed. Various solubilization methods were applied to sewage sludge for enhancing its biodegradability and the combined method, alkaline followed by ultrasonic, gave the highest solubilization efficiency (58%); the solubilized solution was used as the external carbon source for denitrification reaction in CSTR. FISH analysis showed that the dominant microorganisms on the carriers were ammonium oxidizing bacteria such as Nitrosomonas spp. and Nitrospirar spp. but low amounts of nitrite oxidizing bacteria as Nitrobacter spp. was also detected.

• Applied Chemistry for Engineering
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• v.3 no.1
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• pp.88-99
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• 1992

For the development of semiconducting photoelectrode to be more stable and efficient in the process of photoelectrolysis of the water, pure titanium rods were oxidized by anodic oxidation, furance oxidation and flame oxidation and used as electrodes. The Indium islands were formed by electrodeposition of "In" thin film on $TiO_2$ and Ti by electrodeposition. Also $A1_2O_3$ and NiO islands were coated on Ti by the electron-beam evaporation technique. The maximum photoelectrochemical conversion efficiency(${\eta}$) was 0.98% for flame oxidized electrode($1200^{\circ}C$ for 2min in air). Anodically oxidized electrodes have photoelectrochemical conversion efficiency of 0.14%. Furnace oxidized electrode($800^{\circ}C$ for 10min in air) has 0.57% of photoelectrochemical efficiency and shows a band-gap energy of about 2.9eV. The $In_2O_3$ coated $TiO_2$ exhibits 0.8% of photoelectrochemical efficiency but much higher value of ${\eta}$ was obtained with the Increase of applied blas voltage. However, $Al_2O_3$ or NiO coated $TiO_2$ shows much low value of ${\eta}$. The efficiency was dependent on the presence of the metallic interstitial compound $TiO_{0+x}$(x<0.33) at the metal-semiconductor interface and the thickness of the suboxide layer and the external rutile scale.