• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.498-505
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• 2008

The selective catalytic oxidation of ammonia was carried out in the presence of natural manganese ore (NMO) and manganese as catalysts using a homemade 1/4" reactor at $10,000hr^{-1}$ of space velocity. The inlet ammonia concentration was maintained at 2,000 ppm, with an air balance. The manganese catalyst resulted in a substantial ammonia conversion, with adsorption activation energies of oxygen and ammonia of 10.5 and 22.7 kcal/mol, respectively. Both $T_{50}$ and $T_{90}$, defined as the temperatures where 50% and 90% of ammonia, respectively, are converted, decreased significantly when alumina-supported manganese catalyst was applied. Increasing the manganese weight percent by 15 wt% increased the lower temperature activity, but 20 wt% of manganese had an adverse effect on the reaction results. An important finding of the study was that the manganese catalyst benefits from a strong sulfur tolerance in the conversion of ammonia to nitrogen.

• Applied Chemistry for Engineering
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• v.17 no.1
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• pp.1-11
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• 2006

Non-thermal plasma technology for air pollution control, which are NOx, SOx, VOCs, soot, etc., is reviewed. In the early parts of the paper, generation of non-thermal plasma and plasma chemical process are introduced to provide an appropriate plasma condition (electron energy density) for treating air pollutions. Recent results on numerical simulation, optical diagnostics, and gas treatment are provided to characterize an optimal design of plasma generation and plasma chemical process. These data are also helpful to understand unique features of non-thermal plasma process that is achieved with relatively low temperature conditions, i.e. low enthalpy conditions of the treated gas molecules. In the later parts of the paper, several examples of recently developed non-thermal plasma techniques are illustrated, in which technical and economical assessments of the present techniques are provided.

• Journal of the Korean Chemical Society
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• v.47 no.1
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• pp.59-66
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• 2003

The comb-type grafted polymer hydrogels, which composed of N-isopropylacrylamide monomer and oligo(N-isopropylacrylamide-co-tert-butylacrylamide) [oligo(NIPAAm-co-t-BAM)], were synthesized by redox polymerization in 5~10% methanol aqueous solution using ammonium peroxodisulfate (APS) at 4 oC for 24h. The lower critical solution temperatures (LCSTs) of the comb-type grafted hydrogels were decreased with increase of t-BAM content in the grafted copolymer. We observed the effect of crosslinker and concentration of oligo(NIPAAm-co-t-BAM) on the shrinking/swelling ratio of hydrogels. Changes of shrinking/swelling ratio were decreased with increase of concentration of crosslinker. The increase of grafted oligo(NIPAAm-co-t-BAM) in the hydrogel shows an fast changes of shrinking/ swelling rate. The comb-type grafted hydrogels are expected to be valuable for the sensing materials of time-temperature labels(TTLs).

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.1-8
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• 2004

Effects of temperature, discoloration, and conditioning on garlic compositions before and after storage were examined. Proximate composition, soluble solids, pH, organic acids, and total sugars of all samples were not significantly different. Sugar contents were sucrose > fructose > glucose, and included such fructooligosaccharide as 1-kestose, 1-nystose, and 1-F-fructosyl nystose. Allicin contents in control, green discolored, and conditioned garlics were 647,9, 613.8, and 648.0 mg%, respectively. Thirty-two flavor compounds were identified by GC/MSD, including 11 sulfide compounds, 5 acids, and 3 aldehydes. Contents of sulfur compounds, including disulfide(di-propenyl), 2-thiophene methanethiol, thiophene, 3,4 dihydro-3-vinyl-1,2-dithiin, and 2-vinyl-4H-1,3-dithin, and water-soluble pectins in low temperature-stored garlic were higher than those in control, and decreased by conditioning or inducing green discoloration. These results show sulfur compounds and water-soluble pectins accumulated in low temperature stored-garlic, and are then converted into green pigments by alliinase in disintegrated garlic tissues.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.109-114
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• 2006

Yam has been recognized as healthy food due to its various biological activities, such as anti-obesity, antimicrobial, anticancer and immuno-stimulation activities, and its consumption has been increased during last decades. In this study, to investigate low-temperature, long-term storage of yam and to develop processed yam products, yam-putrefactive psychrotrophic bacteria were isolated from rotted yam and identified based on BBL identification system, fatty acid analysis in cell membrane and 16S rDNA sequence analysis. The putrefaction activity of isolated thirteen bacteria was evaluated using yam-slices (NaOCl-treated, autoclaved yam and without treatment), and YAM-10 and YAM-12 were identified as major psychrotrophic putrefactive bacteria. Both YAM-10 (Pseudomonas cepacia) and YAM-12 (Pseudomonas rhodesiae) bacteria grew well at 4$\sim$12$^{\circ}C$ and showed strong activity of polymer degrading enzymes, especially amylase, carboxy methyl cellulase and xylanase, at 20$^{\circ}C$. But they failed to grow at acidic pH (<5) or alkaline pH (>10). Our results suggested that the control of psychrotrophic Pseudomonas sp. by pH change and inhibition of polymer degrading enzymes, such as amy-lase, are necessary to long-term storage of yam.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.732-739
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• 2013

'Akihime' plums picked at mature stage (50-70% red coloration of the fruit skin) were stored at $1^{\circ}C$ under air or controlled atmosphere (CA) storage regime as following 3% $O_2$ + 1, 3, 5, and 7% $CO_2$ for 50 days for the purpose of assessing the effect of CA storage on the maintenance of fruit quality and the reduction of chilling injury. Fruits stored under CA storage regime showed reduced respiration as well as ethylene production rates compared to the fruits stored in air. Quality attributes including weight loss, Hunter 'a' values, soluble solids content, titratable acidity, and firmness showed smallest changes in fruits stored under CA conditions except for 3% $O_2$ + 7% $CO_2$. High incidence of physiological disorders including chilling injury, flesh browning, and decay were found in fruits stored under both air and CA of 3% $O_2$ + 7% $CO_2$. In our study, the CA storage regime of 3% $O_2$ + 5% $CO_2$ was found the most effective for maintaining overall fruit qualities of 'Akihime' plums produced in Korea, also delayed the development of chilling injury including lack of juiciness and flesh browning. From the results, storage at 3% $O_2$ + 5% $CO_2$ was selected as an optimal condition of 'Akihime' plum for extending storage life up to 50 days at $1^{\circ}C$.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.8 no.4
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• pp.101-109
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• 1987

포도나무에 발생하는 병(病)은 현재 19종(1986)이 알려져 있으며, 병 발생의 중요도가 여러 가지 요인의 변화에 따라서 바뀌고 있다. 그 요인을 우선 약제사용면에서 보면 약제종류의 변화, 살포방법의 변화, 살포회수의 변화 및 포장위생의 불철저 등을 들 수 있고 재배적인 면에서 보면 품종의 변천, 재배형의 변화, 시비방법의 변화 등을 들 수 있다. 또 해와 지역에 따라서는 이상저온, 다우다습(多雨多濕), 건조 등 기상 조건이 변함에 따라서도 병의 발생은 크게 달라 진다.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.7 no.6
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• pp.73-79
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• 1986

과실을 수확한 후 판매하거나 저장고에 넣고나면 한해의 과수원 관리는 끝났다고 생각하여 겨울철의 과수원 관리를 게을리하는 경우가 있으나, 내년도의 과수원 관리를 보다 성공적으로 하기 위해서는 과수가 생육을 정지하고 겨울잠을 자는 겨울철의 과수원 관리가 매우 중요하다. 월동병해충의 구제등 겨울철의 과수원 관리를 보다 적극적으로 함으로써 생육기간중의 병해충의 발생밀도를 감소시킬 수 있을 뿐만 아니라 이상저온에 따른 동해의 피해를 경감시킬 수 있어 과실의 수량과 품질을 향상시킬 수 있다.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2004.07a
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• pp.50-50
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• 2004

소비자의 수요 변화에 부응한 고품질, 안전 농산물의 생산에 대한 요구가 증대되고 있는 현실에서, 생산자와 소비자가 신뢰할 수 있도록 미생물 안전성이 확보된 안전 농산물 생산을 위한 기술 개발 및 연구가 필요한 실정이다. 본 연구에서는 주로 생식으로 섭취되는 엽채류 중 상추를 대상으로 하여 살균액 처리 방법에 의한 미생물 경감을 조사하였다. 그램 양성균인 Becillus subfilis와 그램 음성균인 Escherichia coli, 저온 식중독균인 Listeria monocytogenes를 대상으로 하여 과산화수소수, 차아염소산나트륨 수용액, 초산수용액의 미생물 감소 효과를 측정한 결과 3% 과산화수소수 용액에 1분 이상 침지하는 방법이 90% 이상 (1/10 수준)의 경감 효과를 보였다. (중략)

• Elastomers and Composites
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• v.31 no.4
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• pp.247-255
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• 1996

금속이나 고분자 재료에 비하여 세라믹스는 우수한 내열성과 고온 물성을 가지고 있음에도 불구하고, 잘 깨지는 특성과 제조시 많은 열량을 필요로 하는 단점 때문에 그 동안 고온 구조용 부품으로서 광범위하게 사용되지 못하였다. 본 연구에서는 polycarbosilane을 이용하여 C/C 복합체를 포함한 산화물 및 비산화물 세라믹 복합체의 저온 치밀화 제조 공정을 확립하였다. polympr precursor를 열처리하여 얻은 $Al_2O_3$와 SiC 장섬유를 대표적인 산화물, 비산화물 세라믹스인 알루미나와 탄화규소에 각각 보강하여 파괴에너지가 기존의 단체 세라믹스에 비하여 10배 이상 향상된 세라믹 복합체를 제조하였다. 복합체 제조시 polycarbosilane을 결합제로 첨가하였으며 polycarbosilane이 SiC로 전이되는 $1150^{\circ}C$에서 열처리하여 이론 밀도의 73% 이상을 얻었다.