• Korean Chemical Engineering Research
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• 제47권5호
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• pp.546-552
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• 2009

이번 연구에서는 밀배아유의 기능성 향상을 위해 고정화 효소를 이용한 밀배아유의 효소적 에탄올 반응을 수행했고, 효소적 에탄올 반응의 비가압조건과 가압조건을 중점적으로 비교 분석했다. 비가압조건 효소적 에탄올 반응 수행은 밀배아유와 99.9% 에탄올 혼합물에 두 가지 고정화 효소인 Lipozyme TL-IM과 Lipozyme RM-IM를 1~5 w%(밀배아 기준 무게비)로 25 ml 플라스크에 shaking machine 상에서 $40{\sim}70^{\circ}C$, 120 rpm 조건으로 실험을 수행했다. 가압조건상에서의 효소적 에탄올 반응 조건은 고정화 효소 2 w%, 반응 시간 24시간, 반응 온도 $40{\sim}60^{\circ}C$ 및 반응 압력 75, 100, 150, 200 bar으로 수행했다. 실험으로부터 회수된 sample은 트리글리세라이드의 분해 정도를 살펴보기 위해 모노-, 디-, 트리글리세라이드를 HPLC를 이용하여 분석했다. 밀배아유의 전반적인 전환율은 반응온도와 고정화 효소의 농도에 따라 증가했고, 최적 반응 조건은 가압조건 $50^{\circ}C$, 100 bar이었다.

• 한국환경농학회지
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• 제32권4호
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• pp.343-347
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• 2013

BACKGROUND: Control of alternate bearing satsuma mandarin in Jeju is very important to maintain the optimum price of fruit and get the sustainable income of farmers. Unlike orange, Satsuma mandarin is well known to sensitive on alternate bearing. We carried out the experiment to know the effect of foliar application of $GA_3$ on the flowering and fruit quality of satsuma mandarin (C. unshiu Marc. cv. Miyagawa). METHODS AND RESULTS: To experiment, the treatments consist of control, different concentration of $GA_3$ (25, 50 and 100 mg/L), machine oil emulsion 100 times and mixture of various concentration of $GA_3$ (25 and 50 mg/L) with machine oil emulsion 100 times which it was applied on 15 year-old Miyagawa satsuma mandarin at December 29, 2011. Foliar application of $GA_3$ in winter reduced the flowering of satsuma mandarin. Flower-leaf ratio was significantly reduced at 100 mg/L $GA_3$, while no differences observed in low concentration of $GA_3$ (25 and 50 mg/L). However, it was significantly decreased to 0.19 in application of $GA_3$ 25 and 50 mg/L with machine oil emulsion 100 times mixture. Number of leaves per fruit was significantly increased as foliar application of $GA_3$ also it reduced the fruits remarkably. Soluble solid contents and Hunter's a of peel color ratio showed no difference among $GA_3$ single treatments, but it was reduced in $GA_3$ 25 and 50 mg/L with machine oil emulsion 100 times mixtures significantly. From the results, it has been found that higher $GA_3$ concentration can reduce the number of flowers on the alternate bearing of satsuma mandarin. However, it was found that lower concentration of $GA_3$ with machine oil emulsion mixture 100 times can reduce flowering. CONCLUSION(S): The foliar application of $GA_3$ (100 mg/L) can alleviate alternate beraring. Also, mixture of lower concentration of $GA_3$ with machine oil emulsion 100 times can retard flowering more significantly while it needs further confirmation.

• 공업화학
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• 제10권3호
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• pp.438-444
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• 1999

국내에서 생산되는 현미겨는 약 8.4~14.7 wt %의 지질을 포함하고 있으나 지방산의 양이나 조성은 현미겨의 형태, 토질 상태, 도정과 같은 전처리나 정미도에 영향을 받는다. 현미겨에 포함되어 있는 지질은 보통 palmitic acid, linolenic acid, linoleic acid, oleic acid, stearic acid, tocopherol, squalene 등과 같은 지방산으로 나눌 수 있다. 본 연구에서는 초임계유체를 이용하여 현미겨에서 squalene을 함유한 지방산을 추출하였으며, 각각의 공정에 ethanol을 첨가하여 초임계유체 추출을 시행하였다. 추출물은 GC-MSD로 분석을 하였고, 추출된 현미유의 양은 공정 온도, 압력에 따라 달랐으며, 조성은 초임계 이산화탄소의 환산밀도 (${\rho}_{\gamma}$ reduced density)에 영향을 받았다. 4시간의 공정시간에 약 70~80%의 현미유가 추출되었으며, ethanol을 첨가한 초임계유체 추출은 일반 초임계유체 추출에 비해 추출시간이 단축되며 동시에 추출량이 증가됨을 알 수 있었다. 또한 용매추출 공정에서 검출되지 않았던 squalene이 초임계유체 추출과 ethanol올 첨가한 초임계유체 추출에서 추출됨이 확인되었다.

• Journal of Advanced Research in Ocean Engineering
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• 제4권1호
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• pp.1-6
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• 2018

Subsea pipelines are designed to transport mixtures of oil, gas, and their associated impurities from the wellhead that can have temperatures as high as $100^{\circ}C$, while the external temperature can be as low as $5^{\circ}C$. Heat can be lost from the subsea pipeline containing high-temperature fluid to the surrounding environment. It is important that the pipeline is designed to ensure that the heat loss is small enough to maintain flow and avoid the unwanted deposition of hydrate and wax, which occurs at a critical temperature of approximately $40^{\circ}C$. Therefore, it is essential to know the heat loss of subsea pipelines under various circumstances. This paper presents a comparison between numerical analyses and existing theoretical formulas for different backfills and burial depth.

• 자연과학논문집
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• 제5권2호
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• pp.63-73
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• 1992

There are many methods of obtaining butadiene described in the literature. In the america it is produced largely from petroleum gases, i.e., by catalytic dehydrogenation of butene of butene-butane mixtures. Butadiene can be recovered from the $C_4$ residue of an olefin plant by distilling off a fraction containing most of the butadiene, catalytically hydrogenating the higher acetylenes to olefins and separating the product from other olefins and isobutane by extraction. Also it can be obtained by cracking naphtha and light oil. Among the individual dienes of commercial importance, 1, 3-butadiene is of first importance. It is used primarily for the production of polymers.In the present paper, it was investigated for a effect of the formation and the growth inhibition of popped corn polymer in butadiene extraction unit. As a result of study, inhibitors, $NaNO_2$ and TBC were good effective for inhibition of the formation and growth in popcorn polymer. The rational formula of popcorn polymer obtained was $(C_4H_6)_x$.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.749-752
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• 2014

New software was developed for the assignment of elemental formulae based on high-resolution mass spectra and subsequent hydrogen/deuterium exchange data. Entire peaks in high-resolution mass spectra were grouped by their Kendrick mass defect values, and the weighted RMS deviations between theoretical and experimental values were used to determine elemental formulae. After this initial assignment, formulae containing deuterium atoms were sorted in order to interpret hydrogen/deuterium exchange spectra. The software was successfully applied to hydrogen/deuterium exchange spectra of resins and aromatic fractions from heavy crude oil.

• 한국자동차공학회논문집
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• 제8권2호
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• pp.57-63
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• 2000

This paper deals with a study on combustion and emission characteristics of a direct injection diesel engine dual fueled with natural gas. Dual fuelling systems tend to emit high unburned fuel especially at low load, resulting in a decreased thermal efficiency. This is because natural gas-air mixtures are too lean for flame to propagate under low load conditions. Suction air quantity and injection timing controls are very useful to improve emissions and thermal efficiency at low load.

• 한국미생물·생명공학회지
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• 제36권4호
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• pp.343-352
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• 2008

프랑킨센스는 감람나무 종에서 얻어지는 gum resin으로, 성분은 5-9% 방향정 에센셜 오일, 알코올-용해성인 65-85% resin과 수용성인 gum 잔여물로 구성된 복합물이다. 프랑킨센스의 알코올 용해성인 resin 성분들의 항염증 작용은 잘 알려져 있으나, 방향성 에센셜 오일 성분이 알러지성 천식에 작용을 하는지의 여부는 보고되지 않았다. 실험은 프랑킨센스 에센설 오일(BSEO)이 ovalbumin(OVA)으로 유발된 알러지성 천식 생쥐 모델에 미치는 영향을 조사하기 위해 수행하였다. BALB/c 생쥐는 OVA로 복강감작 후 OVA 기도 투여로 면역반응을 유발시켰다. 실험그룹은 0.3% BSEO를 8주간 흡입시켰다. OVA로 감작, 유발시킨 BALB/c 생쥐에서 기도내 호산구 침윤증가, 점액분비 증가와 기도과민성이 나타났다. 이에 비하여, BSEO 처치군에서 BALF내 호산구수, 술잔세포의 과증식, 기도과민성이 감소되었다. BALF내 사이토카인 분석 결과, BSEO는 Th1 사이토카인인 IFN-$\gamma$를 증가시켰으며 Th2 사이토카인인 IL-4, IL-5와 IL-13을 감소시켰다. 또한, OVA-specific IgE와 eoxtain 분비를 억제시켰다. BSEO 흡입 군에서 종격동 림프절의 $CD4^+$, $CD3^+/CCR3^+$, 및 $B220^+/CD23^+$ 세포들 또한 감소되었다. 이상의 결과에서 BSEO는 Th1/Th2 관여 면역조절인자로 판단되며, BSEO 흡입으로 간단하고 경제적인 방법으로 알러지성 기도 염증 치료가 가능할 것으로 사료되었다.

• 한국주조공학회지
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• 제7권4호
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• pp.366-379
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• 1987

The influences of some factors on the variation of compression strength of $CO_2$ process were investigated with an attention given to use of high $SiO_2\;/Na_2O$ silicate, addition of organics and gassing operation. 1) Higher ratio binder offers faster rates of hardening with lower $CO_2$ consumption requiring more concentration for a good strength development. A mixture containing 4 percent of 2.7:1 ratio silicate produces the strength above $8kg\;/\;cm^2$ after 80 seconds gassing, but 5% and 6% respectively of 3.0:1 and3.3:1 ratio silicate are necessary to achieve equivalent levels of strength. 2) The correct water content in sand mixtures containing higher ratio silicates is necessary for the better strength properties to be obtained. The addition of 1% water to the sand mixtures bonded with 5%,3:1 ratio and 6%,3.3:1 ratio silicates maintains near-maximum strength on extended gassing. 3) When higher ratio silicates with 3:1 and 3.3:1 ratios are used,the addition of organic additives such as oil, sucrose and polyol results in considerable changes in strength. The presence of 1.0 to 1.5 percent of polyol produces a noticiable improvement 4) Gas diluted with air raises the efficiency of gas utilization. When gas contains 50 percent $CO_2$, the efficience is significantly increased with the best strength in the silicates having high ratios of 3:1 and 3.3:1. 5) The strength of molds is liable to change on storage with the reduction in water content. The magnitude of the strength change is determinded with the mole ratio. The presence of polyol in the mixture with 3.3:1 ratio silicate has a pronounced effect on maintaining the gassed strength.

• 대한기계학회논문집
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• 제10권1호
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• pp.121-130
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• 1986

Using the sbsorption coefficients and the weighting factors of the gray gas, the total emissivities of C $O_{2}$- $H_{2}$O and C $O_{2}$- $H_{2}$O- transient species-soot gas mixtures can be expressed by the following equation, [a numerical formula] Where, $a_{i}$ and $K_{i}$ represent the weighting factor and the absorption coeffient of i-gray gas respectively; L is the pathlength of the gas. This equation is widely used for the analyses of the radiation heat transfer in the combustors of internal combustion engines and in the furnace of external combustion engines. In this work, a simple calculation model of the weighting factor and the absorption coeffient of the above equation was developed. The weighting factors and the absorption coefficients of combustion products were calculated by applying the model to various kinds of fossil fuels such as coal and heavy oil. Then, the computed total emissivities for each fuel and pathlength were compared with measured and calculated values which have been already published in the literatures. The followings were the results obtained through the comparisons between the calculated emissivites and the published values; the developed model for the calculations of the weighting factor and the absorption coefficient of C $O_{2}$- $H_{2}$O and C $O_{2}$- $H_{2}$O- transient species-soot gas mixtures could be applied over the wide ranges of the temperature and the pathlength; the errors between the total emissivities calculted and the values published were maximum 10%, and average 1%, respectively.