• Current Research on Agriculture and Life Sciences
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• v.8
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• pp.83-88
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• 1990

This experiment was conducted to investigate the effect of $CO_2$ treatment on quality of strawberry during storage. Gas composition in polyethylene(P.E.) film bag during storage was changed markedly at early stage of storage and then kept at the level of 8-9% $CO_2$and 1-2% $O_2$. Weight loss and decay were restricted by $CO_2$ pretreatment and P.E. film packaging. Titratable acidity, PH and soluble solids were not changed greatly during storage. Firmness of flesh was increased by $CO_2$ treatment till 14 days of storage and decrease of a value reduced by $CO_2$ treatment and P.E.film packaging, too. Ascorbic acid contents were more high in not packed samples than packed untill 14 days of storage but after that those were more high in P.E.film packed and $CO_2$ treated samples.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.4
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• pp.263-270
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• 2012

Ascorbic acid (Vitamin C) becomes unstable in the aqueous phase by oxygen, light and alkali, etc. The properties are limited in application to cosmetics. The most important factor that determines the destabilization of ascorbic acid in the aqueous phase was tried to understand considering its molecular deformation and degradation. In this study, we changed the polyols and emulsification technique for the stability of ascorbic acid. Then we observed the color and concentration change of ascorbic acid at room temperature and high temperature ($42^{\circ}C$) for 6 weeks and identified the stability using HPLC regularly. As a result, we found that glycerin was the most appropriate polyol for stability of the ascorbic acid. Also the technique of nonaqueous emulsification stabilized ascorbic acid than P/S emulsification. Also, P/S emulsification, glycerin was more stable than propylene glycol. By the results we suggest that ascorbic acid could be stabilized by nonaqueous emulsification method and this data could be applied to stabilization methods for cosmetic products.

• Polymer(Korea)
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• v.38 no.4
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• pp.491-495
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• 2014

Pressure sensitive adhesive (PSA) based on 2-ethylhexyl acrylate (2-EHA)/acrylic acid (AA) copolymer was synthesized using different photoinitiators. Results showed that PSA with Irgacure$^{(R)}$651 (benzyldimethylketal) and Irgacure$^{(R)}$184(1-hydroxy-cyclohexylphenyl ketone) proved to be good for adhesion properties. This may be attributed to strong absorption near 350 nm wavelength and also high solubility in monomer mixtures. The addition of Irgacure$^{(R)}$819, bisacylphosphine oxides as a photoinitiator caused cohesive failure with high loading in a peel test owing to the additional radical formation. It is assumed that the insoluble photoinitiator reacts with oxygene, which may act as a hydrogen donor.

• Food Science and Preservation
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• v.19 no.1
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• pp.26-30
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• 2012

The effect of browning inhibitors on quality properties of fresh-cut strawberries was investigated. Half-cut strawberries were treated with dipping solutions alone and with combinations of 1% ascorbic acid, 1% citric acid, 1% sodium chloride, and 1% magnesium chloride, were packaged with low density polyethylene bags, and were kept for 24 hours at $4^{\circ}C$. The levels of oxygen and carbon dioxide in the packages of the samples treated with the combined solutions were the highest and the lowest, respectively. The loss of L value and flesh firmness of fresh-cut strawberries was retarded by the combined solutions than by the dipping solutions alone. The soluble solids and pH were not affected by the browning inhibitor. These results suggest that mixture of ascorbic acid, citric acid, sodium chloride, magnesium chloride may prevent browning and softening of fresh-cut strawberries.

• Composites Research
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• v.26 no.5
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• pp.309-314
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• 2013

Highly ablation resistant carbon nanotube (CNT)-phenolic composites were fabricated by the addition of low concentrations of CNT nanofiller. Tensile and compressive properties as well as ablative resistance were significantly improved by the addition of only 0.1 and 0.3 wt% of uniformly dispersed CNTs. An oxygen-kerosene-flame torch and a field emission scanning electron microscope (FE-SEM) were used to evaluate the ablative properties and microstructures of these CNT-phenolic composites. Thermal gravimetric analysis (TGA) revealed that the ablation rate was lower for the 0.3 wt% CNT-phenolic composites than for neat phenolic or the composite with 0.1 wt% CNT. Ablative mechanisms for all three materials were investigated using this TGA in conjunction with microstructural studies using a FE-SEM. The microstructural studies revealed that CNT acted as an ablation resistant phase at high temperatures, and that the uniformity of dispersion of the CNT played an important role in this resistance to ablation.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2007.05a
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• pp.375-379
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• 2007

폐비닐 여재(Synthetic Waste Polyethylene Media)를 적용한 부착성장식 공정의 유기물 및 질소${\cdot}$인 제거특성에 관한 Pilot Plant 실험 결과 다음과 같은 결론을 얻을 수 있었다. 1) 제거효율은 $RUNI1{\sim}3$에서 $COD_{cr}$ 91.4, 92.4, 93.9%, T-N 56.9, 61.4, 65.1%, T-P는 모든 단계에서 약 45%이상 제거되어 부하변동시에 강한 대처능력을 나타내었다. 2) BOD용적부하 $0.18{\sim}0.40kg/m^3{\cdot}d$, COD용적부하 $0.28{\sim}0.53kg/m^3{\cdot}d$, ${NH_4}^{+}-N$용적부하 $0.12kg/m^3{\cdot}d$을 나타내었다. 3) 도시하수 처리를 위한 생물학적 질소 및 인 제거공법을 본 여재를 이용하여 공정설계시 고려할 사항들과 적절한 대처방법을 다음과 같이 제시할 수 있다. - 1차 침전지에서 유기질소 및 유기인 농도가 높다면 유기질소 및 인 부하량을 감소시키기 위하여 1차 침전지를 설치하되 질소 및 인제거에 유리한 $BOD_5/T-N$, $BOD_5/T-P$를 유지할 수 있도록 체류시간을 1시간미만으로 설계하는 것이 경제적이라고 판단된다. 만일 유기질소와 유기인의 함량이 낮다면 1차 침전지는 제외하는 것이 유리할 것이다. - 여재의 배치는 폭기조에서 용존산소의 균일분포와 슬러지의 적정탈리를 위해 여재를 상하로 배치하거나 또는 여재끼리 일정 간격을 두어 배치하는 것이 바람직하다. 농촌에서의 처분이 문제시 되고 있는 폐비닐을 적용한 본 연구에서의 수처리특성은 기존 하수처리공정에서의 제거효율에 상응하는 처리특성을 나타내었다. 또한 폐비닐 처분의 문제를 해결할 수 있을뿐만 아니라 하수처리시에도 부하변동 등에 강한 대처능력을 나타내어 기존의 하수처리공정에 대체가능성을 나타내었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1747-1752
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• 2012

The SiOC film of carbon centered system was prepared using bistrimethylsilylmethane (BTMSM) and oxygen mixed precursor by the chemical vapor deposition. The dielectric constant is measured by MIS(metal/insulator/Si) structure, but it could decrease the reliability because the uniformity is not assured. To research the dielectric constant of SiOC film, the range of low polarization was researched in SiOC film using the optical analysis and hardness, and then calculated the dielectric constant of SiOC film with amorphous structure of high degree. After annealing, the dielectric constant of SiOC film was decreased owing to the lowering of polarization, and FTIR spectra of the main bond was shifted to higher wave number. The main bond of 950~1200 cm-1 was composed of the Si-C and Si-O bonds. The intensity increases in Si-O bond infers the bonding strength became stronger than that of deposited film. Annealed SiOC film showed 2.06 in dielectric constant.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.22 no.2
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• pp.27-32
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• 2016

In this experiment, alcohol and blanching treatments were used for food packaging materials, quality of powder yam and sliced yams (5 mm size) were compared by alcohol concentration and time for measuring change of color, weight, moisture content saccharinity and decomposition. 5% and 10% alcohol were used to alcohol treatment for 5, 10 seconds each. Packaging materials were used OPP($30{\mu}m$), PET($25{\mu}m$), ON($25{\mu}m$) and all materials heat sealable were coated. Quality of powder yam were not changed during storage at low temperature however were changed during storage at room temperature after 5 days. In conclusion, powder yam were needed packaging materials with high water barrier property from moisture, sliced yams were high quality when packaged by ON and stored at low temperature. Therefore, using packaging materials with low oxygen permeability were expected to reduced quality degradation about browning of powder yam and sliced yams.

• Journal of Life Science
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• v.17 no.8 s.88
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• pp.1172-1175
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• 2007

We observed that exogenously applied ethanol changed the activities of aldehyde oxidases (AO) in the primary roots of maize (Zea mays). The stimulatory effect of ethanol on the aldehyde oxidase activities was concentration dependent; the AO activities were slightly weaker with 0.2 - 0.4% ethanol and stronger with 0.8 - 1.0% ethanol than the level of control. The promotion of AO activities was not explained by the increased transcription of two AO genes in maize. In contrast, ethanol strongly increased the amount of AO proteins, indicating that ethanol enhanced AO activities by promoting the translation. Among three alcohols including ethanol, methanol and isopropanol, only ethanol promoted AO activities. These results suggested that enhancement of AO activities was specific to ethanol, whose level could be naturally increased when the plant roots drove fermentation to overcome low oxygen stresses.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.974-980
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• 1996

A biosensor was prepared with dual cathode electrode and immobilized enzyme membrane. A nylon net was used for the immobilization of glucose oxidase and alcohol oxidase. The immobilized enzymes were placed on the surface of the electrode which was prepared with one anode and two cathodes as an oxygen electrode. The determination of components by the biosensor was based on the consumption of dissolved oxygen. The optimum condition of this system was 0.1 M potassium phosphate buffer solution, pH 7.5 at $35^{\circ}C$. Glucose and ethanol in takju were simultaneously determined by the biosensor. Comparing with UV-spectrophotometer and gas chromatograph for cross checking, there was a good correlation between the biosensor and the conventional methods. Biosensor with dual cathode electrode required no clarification or pretreatments. It was used for simultaneous determination of glucose and ethanol during the fermentation of takju.