• Journal of Photoscience
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• 제5권1호
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• pp.17-22
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• 1998

Changes of chlorophyll fluorescence and xanthophyll cycle pigment contents in maize leaves were investigated dunng desiccation in darkness or in the light. In darkness, a drastic dehydration of detached maize leaves down to 50% relative water content (RWC) affected photochemical efficiency of photosystem II (Fv/Fm) and pht)tochemical quenching (qP) only slightly. In contrast, desiccation in the light with a moderate intensity led to a pronounced reduction in Fv/Fm with a Fo quenching when RWC was greater than 70%. This reduction in Fv/Fm could be recovered in darkness under hutrod condition. In leaves with RWC below 70%, significant reduction in Fv/Fm was accompanied by an increase of Fo, which could not be reversed within 5 h in darkness under humid condition. The nonphotochemical quenching increased during desiccation in the light with a concomitant rise in zeaxanthin at the expense of violaxanthin. Pretreatment with dithiothreitol (DTT), an inhibitor of zeaxanthin synthesis, inhibited the development of nonphotochemical quenching and prevented the xanthophyll interconversion during desiccation in the light. These results suggest that even light with a moderate intensity becomes excessive under dehydration and zeaxanthin-associated photoprotection of photosynthetic apparatus against photodamage is involved, but the protection is not complete against severe desiccation.

• 한국식품과학회지
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• 제11권4호
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• pp.258-263
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• 1979

알루미늄-아크릴 필름을 사용하여 제작(製作)한 곡면(曲面) 집광장치(集光裝置)에 의(依)한 공기(空氣)의 가열(加熱)과 가열(加熱)된 공기(空氣)를 이용하여 농산물(農産物)의 건조(乾燥)에 이용(利用)하는 실험(實驗)을 통하여 다음과 같은 결과를 얻었다. 1. 공기(空氣)를 열(熱) 교환(交換) 매체(媒體)로 하고 $1{\;}m^2$의 곡면(曲面) 집광식(集光式) 반사판(反射板)에 의(依)하여 가열(加熱)된 흡광관(吸光管)에 송입(送入)할때의 열(熱) 교환(交換) 효율은 1.39 %이었다. 2. 흡광관(吸光管) 내부(內部)에 baffle을 설치할 경우 baffle의 수(數)에 따라 열(熱) 교환(交換) 효율이 증가(增加) 하였으며 74 cm의 흡광관(吸光管)에 17매(枚)을 설치할 경우 33 %의 효율 증대(增大)를 가져왔다. 3. 본(本) 태양(太陽) 열(熱) 이용(利用) 장치(裝置)에 의(依)하여 가열(加熱)된 공기로 무우를 $70^{\circ}C$에서 열풍 건조(乾燥) 하였을 경우 건조에 필요한 열량중 58 %를 절약(節約)할 수 있었다. 4. 반사판(反射板)을 scale-up할 경우의 가득(可得) 열량(熱量) 및 열(熱) 이용(利用) 효율과의 관계는 대수(對數)-대수(對數) 좌표(座標0에서 직선적(直線的) 관계(關係)를 보였다.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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• pp.60-72
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• 2003

To investigate the effect of cholesterol in liposome on the stability of incorporated retinol, the physico-chemical experiments for various amounts of cholesterol-containing liposomes were performed. Liposome with retinol containing cholesterol was prepared as multilamella vesicles(MLVs) by dehydration/rehydration method. The incorporation efficiency of retinol into liposome was maximized as 99.31 % at 50:50 (phosphatidylcholine/cholesterol) at pH 9. The stability of incorporated retinol at low storage temperature was enhanced with increasing cholesterol content than at high storage temperature. For example, incorporated retinol in liposome at glycine buffer(pH 9} was degraded slowly during storage at 4. The degradation of retinol in liposomes was slower at pH 9 than at pH 7. These results supported that cholesterol in liposome increased largely the stability of incorporated retinol.

• 한국물환경학회지
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• 제32권5호
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• pp.458-464
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• 2016

This study evaluated the dewatering efficiency of inorganic dehydrating agents that contain oyster shells. A filter press dehydrator was used for this study. The experiments were performed by the single injection of calcium-based chemicals, the single injection of oyster shells, and the mixed injection of oyster shells and calcium-based chemicals. The moisture content of the dewatered cake generated after dehydration confirmed that the best dewatering efficiency was found at the mixing ratios of CaCO₃ to sludge, oyster shell to sludge, and inorganic dehydrating agent to sludge of 3:1, 10:1, and 1.5:2.5:1, respectively. The moisture contents exhibited less than 58% when the injection mixing ratio of inorganic dehydrating agent to sludge was 1.5:2.5:1. From EPS, SEM, and EDX analysis, it was found that the calcium adsorbed on the sludge surface could reduce extracellular polymeric substances (EPSs) and enhanced the dewaterbility. Based on the above results, it is considered possible to apply inorganic dehydrating agents containing recycled oyster shells in sludge dewatering in order to reduce sludge.

• Korean Membrane Journal
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• 제6권1호
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• pp.10-15
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• 2004

We developed a water-selective ceramic composite membrane for use as a dehydration membrane reactor for dimethylether (DME) synthesis from methanol. The membranes were modified on the porous stainless steel support by the sol-gel method accompanied by a suction process. The improved membrane modification process was effective in increasing the vapour permselectivity by removal of defects and pinholes. The optimized alumina/silica composite membrane exhibited a water permeance of 1.14${\times}$10$^{-7}$ mol/$m^2$.sec.Pa and a water/methanol selectivity of 8.4 at permeation temperature of 25$0^{\circ}C$. The catalytic reaction for DME synthesis from methanol using the membrane was performed at 23$0^{\circ}C$, and the reaction conversion was compared with that of the conventional fixed-bed reactor. The reaction conversion of the membrane reactor was much higher than that of the conventional fixed-bed reactor. The reaction conversion of the membrane reactor and the conventional fixed-bed reactor was 82.5 and 68.0%, respectively. This improvement of reaction efficiency can last if the water vapour produced in the reaction zone is removed continuously.

• 한국식품영양학회지
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• 제35권6호
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• pp.426-434
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• 2022

In this study, the effect of osmotic drying conditions of mangoes on hot air drying was investigated. Four different osmotic agents of 60 Brix, such as S60, SM10, HF80, and SG25, were prepared. Mango slabs were osmotically dried with the agents at a ratio of 1:4 (w/w) for up to 8 hours. SG25 showed the lowest weight reduction and moisture loss during the process. As a result of hot-air drying, all samples showed a high correlation with the Page model (0.9761~0.9997), and the required drying time of all samples that were osmotically dried was reduced compared to the non-osmotically dried group. After hot-air drying, the pH value increased according to the drying temperature. The L, a, and b values and the total polyphenol content also decreased. Through this study, the possibility of osmotic drying was confirmed to increase the efficiency of hot air drying of mangoes, which is expected to contribute to the industrial use of domestic mangoes.

• Food Science and Biotechnology
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• 제14권5호
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• pp.604-607
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• 2005

In this study, the effect of ${\beta}$-sitosterol (SS) in the liposome bilayer on the stability of incorporated retinol was evaluated. Retinol was incorporated into liposomes consisting of various ratios of soybean phoaphatidylcholine (PC) to SS, while liposomes were prepared as multilamellar vesicles by the dehydration/rehydration method. Retinol was readily incorporated into liposomes with various SS contents, with incorporation efficiencies higher than 98% for all conditions. The incorporation efficiency of retinol increased slightly as the SS content in liposomes increased. Its average particle size also increased as the SS content increased. Mean particle size at PC to SS ratios of 100:0, 90:10, 80:20, 70:30, 60:40, and 50:50 were 12.16, 17.57, 35.00, 40.62, 83.45, and $88.94\;{\mu}m$, respectively. Liposomal retinol degradation in aqueous solution was measured with respect to SS content at various periods of time at four different temperatures of 4, 25, 37, and $50^{\circ}C$, and the stability of the incorporated retinol enhanced as the SS content increased. At $4^{\circ}C$, for example, retinol in the liposomes of 50:50 (PC:SS) remained at 84.42% after storage for 10 days, while in 100:0 (PC/SS) it remained at 42.62%. These results indicate that SS content in liposomes played an important role in the incorporation efficiency of retinol and its stability.

• 한국식품과학회지
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• 제29권2호
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• pp.292-301
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• 1997

건조채소류의 제조시 품질손상을 줄이고자 삼투건조와 steam 및 boiling water, microwave를 이용하여 전처리를 행한 후 열풍건조하여 적절한 전처리 방법을 알아보고자 건조와 재수화 공정을 행하여 각 공정의 물리적인 특성을 조사하였으며, 기존의 건조 모델을 적용하여 수분이동 메카니즘을 설명하고, 건조당근의 관능적 특성을 조사하였다. 전처리는 처리시간이 길수록 수분과 carotene 함량이 낮아졌으나 물리적인 특성을 고려하여 최적 처리 시간을 STEAM과 WATER 는 각 10분, MICRO는 1분으로 결정하였다. 최적 조건에서 전처리를 행한 후 $69^{\circ}C$, 상대습도 33%의 열풍건조 조건에서 건조를 행한 후 열탕에서 10분간 재수화 하여 carotene 및 수분함량, 색도와 복원율 등을 알아본 결과, 건조 효율은 타처리구가 삼투처리보다 우수하였으나 carotene 함량은 삼투건조가 높은 값을 보였고 그 효과는 재수화 후에도 지속하였다. 전처리를 각기 달리한 당근의 품질에 대하여 관능검사를 실시한 결과, 외관과 색도 그리고 종합적인 기호면에서 건조 후의 품질은 삼투처리한 열풍건조의 경우가 전처리 하지 않은 동결건조 처리구 보다 건조 및 재수화 후 높은 점수를 나타내었다. 건조공정을 기존의 건조모델로 표현하고자 적합성 여부를 조사해 본 결과 전처리방법에 관계없이 quadratic 모델이 가장 높은 적합도를 보여 수분의 이동을 시간의 함수로 나타낼 수 있었다. 재수화 공정에의 적용성은 기존의 건조 및 흡습모델로 표현하기는 미흡한 것으로 나타났다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.283-283
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• 1996

The hydrolyzed-lactose milk for the lactase-deficient subject is sweeter than whole milk, and some subjects dislike its taste. To overcome this shortcoming the dried liposomes containing ${\beta}$-galactosidase to digest lactose in milk after drinking were prepared and examined the possible application of this dried liposomes to the lactase-deficient subjects. To improve the stability of conventional liposome suspension, the dried liposomes in the presence of trehalose were prepared by the dehydration-rehydration vesicles method. Small unilamellar vesicles, prepared with egg phosphatidyl cholesterol, and cholesterol, were mixed with ${\beta}$-galactosidase solution and then ;up[jo;ozed. The freeze-dried liposome was rehydrated and centrifuged. The resultant multilamellar vesicles were mixed with trehalose(4g/g lipid) and then lyophilized to produce final dried liposome. Trehalose increased the entrapping efficiency of liposomes by 3 fo1d compared to the liposomes without trehalose (13% vs. 46%).

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 추계학술발표회
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• pp.216-219
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• 2001

In this study, a hydrocyclone operated by centrifugal force was examined as a part of dredge system of lake sediments. It does not help dehydration of the sediments, but also enables the classification of fine particles in the stable and sanitary treatment. Several experiments were performed focusing on the separation efficiency under the condition of room temperature with virtual sediment samples and simulated particles. As a result of the experiment, it was found that the apex size of the cyclone greatly affected the cut diameter(d$_{50}$), and high density particles were separated more effectively.y.