• 약학회지
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• 제40권3호
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• pp.243-250
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• 1996

In order to formulate aqueous multivitamin solutions containing both oil-soluble (A, D, E) and water-soluble vitmains ($B_1,\;B_2,\;B_6,\;B_{12}$, C and niacinamide) in 1ml-dose, the effects of various additives such as cosolvents (propylene glycol, polyethylene glycol, glycerin), a sweetener (sorbitol) and a surfactant (Cremophor$^{\circledR}$ RH40) on the solubility of oil-soluble vitamins in water were evaluated. Cremophor$^{\circledR}$ RH40 showed the excellent capacity on the solubilization of oil-soluble vitamins, and the simultaneous addition of cosolvents and surfactant resulted in synergetic effects on the solubilization of oil-soluble vitamins. The effects of the combination of the cosolvents and sweetener on the stability of multivitamin solutions were also evaluated by determining the amount of vitmain A and $B_1$ remained in the solutions after storing at $40^{\circ}C$ for 9 weeks. The formulation consisting of Cremophor$^{\circledR}$ RH40 15%, PG 20%, and sorbitol 20% resulted in the best stability of vitamin A and $B_1$. The stability of vitamin A and $B_1$ in this formulation was evaluated at 50, 60, and $70^{\circ}C$ up to 40 days. The shelf-lives of vitamin A and $B_1$ in the formulation, calculated using the Arrhenius equation, were 1,521 days and 475 days at $20^{\circ}C$, respectively.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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• pp.343-356
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• 2003

Yew (Taxus cuspidata Sieb.) chose that grow as medicine, food, decorative plant in Korea's Kyong-Gi province surroundings. Extracts of yew extracted leaf of 250 g and stems of 300 g with 1,3-butylene glycol (1,3-BG), propylene glycol (PG) and water. As results, external appearance of leaf extract of yew was slightly brown clear extract. The pH was 5.3$\pm$0.5, and specific gravity was 1.012$\pm$0.05, and refractive index was 1.375$\pm$0.05. Also, appearance of stem's extract was slightly brown clear extract, and the pH was 5.4$\pm$0.5, and specific gravity was 1.016$\pm$0.05, and refractive index was 1.358$\pm$0.05. Oil of yew separated from seeds, and extracted polysaccharide high purity from fruits. As a result, specific gravity of oil was 0.987, and obtained 40% of yield. Total polyphenols amount of yew extract is detected 0.563% in leaves, 0.325% in stems, whereas total tannins amount contained 0.054% and 0.037% each in leaves and stems. As effect in cosmetics, the anti-oxidative effect by DPPH method is 75.0% in leaves, and stems was 64.0%. Collagen synthesis rate was shown high activity by 54.16% in stem's extract, 33.18% in leaves' extract. Also, PPE-inhibitory activities were 13.7% and 23.5% each in leaves and stems. Anti-inflammatory effect of yew seed oil displayed superior effect of 41 % than control. Polysaccharide's molecular weight that is gotten from fruits was 5$\times$10$^4$~3$\times$10$^{5}$ dalton, and got 20.0$\pm$5% of yield.

• 한국항해항만학회지
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• 제35권5호
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• pp.365-370
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• 2011

최근 지구 온난화와 더불어 급격한 기후 변화 등으로 여름철 주간 냉방 수요가 급격히 증가하고 있다. 이에 따른 전력 수요량 또한 증가하고 있다. 이런 이유로 세계적으로 에너지 이용 효율 향상에 대한 관심이 높아지고 있고, 최근 국내 및 국외의 축냉시스템을 이용한 주간 전력 피크값을 최소화 하는 연구개발과 실제 적용 사례가 늘어나고 있다. 빙축열시스템의 경우 그 경제적 효과가 높아 그 관심이 높아지고 있는 추세이다. 축냉시스템은 주간 냉방에 사용하는 냉열을 야간에 만들어 탱크에 저장해 두었다가 그것을 낮에 이용함으로써, 갑작스런 부하 증가에 적절히 대응할 수 있는 등 여러 가지 장점을 갖고 있다. 본 실험에서는 슬러리아이스 생성을 위해 냉각표면에서 생성된 슬러리아이스를 분리시키기 위해 유체보다 밀도가 낮은 역전유동 물질을 삽입하여 역전 유동층을 형성하였으며, 역전유동층의 유동에 의해 관군으로 구성되어 있는 냉각튜브 표면에 빙부착이 심화되기 전에 얼음 입자를 분리시켜 수 내지 수십 미크론 단위의 슬러리아이스를 생성하도록 하였다.

• 통합자연과학논문집
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• 제14권3호
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• pp.99-106
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• 2021

A mixture of alcohol and water is commonly used as antifreeze, liquor, and the fundamental solvents for the manufacture of cosmetics, pharmaceuticals, and inks in our daily life. Since various properties of alcohol water mixtures such as density, boiling or melting point, viscosity, and dielectric constant are determined by their mixing ratio, it is very important to know the mixing ratio to predict their properties. One of simple method to find the mixing ratio is measuring the density of the mixtures. However, it is not easy to predict the mixing ratio from the density of the mixtures because the relationship between mixing ratio and density has not been established well. The relationship is dependent on the relative sizes of solute and solvent molecules, and their interactions. Recently, an empirical model to predict the density of glycerol water mixture from their mixing ratio has been introduced. The suggested model is simple but quite accurate for glycerol water mixture. In this article, we investigated the applicability of this model to different alcohol water mixtures. Densities for six different alcohol water mixtures containing various alcohols (e.g., ethylene glycol, 1,3-propane diol, propylene glycol, methanol, ethanol, and 1-propanol) were simulated and compared to experimentally measured ones to investigate the applicability of the model proposed for glycerol water mixtures to other alcohol water mixtures. The model predicted the actual density of all alcohol water mixtures tested in this article with high accuracy at various ratios. This model can probably be used to predict the mixing ratio of other alcohol water mixtures from their densities beyond 6 alcohols tested in this article from their densities.

• 공업화학
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• 제22권2호
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• pp.149-154
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• 2011

연료전지 스택 작동환경에서의 열노화 특성을 살펴보기 위하여 다양한 고무 compound의 내열 및 압축 영구 줄음률의 평가를 실시하고, 스택의 장시간 운전을 통해 접합할 수 있는 대상액인 $H_2SO_4$, $H_2O$, LLC (Ethylene glycol : $H_2O=50:50$)에 대하여 장시간 평가를 실시하였다. NBR과 EPDM은 시간이 경과할수록 침적액의 변색하는 것을 알 수 있었으며, VMQ는 $H_2SO_4$ 분위기에서 시간에 따라 고무가 노화되는 것을 TGA, SEM, EDS 분석을 통하여 확인하였다.

• Fisheries and Aquatic Sciences
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• 제24권2호
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• pp.63-77
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• 2021

The aim of this research was to investigate different factors, including cryoprotective agents (CPAs), diluents, dilution ratios, equilibrium times, freezing rates, and thawing methods to optimize cryopreservation protocols for large yellow croaker (Larimichthys crocea). The parameters evaluated were sperm motility, sperm activity index (SAI), survival rate, and DNA damage. Different types of CPAs, such as dimethyl sulfoxide (DMSO), propylene glycol (PG), ethylene glycol (EG), methanol, and glycerol, were tested for sperm preservation. The highest motility, SAI, and survival rate were observed when EG was used. Different diluents such as Stein's solution, Hank's balanced salt solution, marine fish Ringer's solution, artificial seminal plasma (ASP) of small yellow croaker, and Cortland solution were investigated. The highest post-thaw motility was observed upon using ASP as the diluent. Different concentrations of EG were then mixed with ASP to identify the optimal EG concentration. Experimental results showed that the motility (70.33 ± 1.20%), SAI (5), and survival rate (78.30 ± 0.42%) of post-thaw sperm were optimum when 10% EG and ASP were used as the CPA and diluent of cryopreservation, respectively. Post-thaw sperm motility was high at equilibration times below 150 s and at an optimum dilution ratio of 1:1 (sperm: CPA + diluent) and was not significantly different compared with fresh sperm motility. The freezing rate was found to be slow below -10℃/min. The thawing temperature of 45℃ was identified as ideal. The percentage of tail DNA in post-thaw sperm at 10% EG and ASP was also investigated and was found to have more significant DNA damage than that in fresh sperm but significantly lower damage than that in post-thaw sperm at EG concentrations of 5%, 15%, and 20% (p < 0.05). The cryopreservation protocols obtained in this study will be useful in large yellow croaker hatcheries.

• 한국식품과학회지
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• 제29권3호
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• pp.452-459
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• 1997

본 연구는 추출 pH가 분리 대두 단백질 필름의 인장 강도, 신장률 및 수증기 투과도에 미치는 영향에 대하여 조사하였다. 산성(pH 2.0, pH 3.0), 중성(pH 7.0) 및 알칼리성(pH 10.0, pH 12.0)에서 분리 대두 단백질을 추출하고 이로부터 가식성필름을 제조하였을 때, 산성에서 추출한 단백질로 제조한 $SPI_2$와 $SPI_3$ 필름의 인장 강도가 각각 2.881 MPa, 2.804 MPa로서 중성이나 알칼리성 영역에서 추출하여 제조한 가식성 필름보다 높게 나타났으며, $SPI_3$ 필름의 수증기 투과도는 필름의 두께가 $55\;{\mu}m$에서 $72\;{\mu}m$로 증가함에 따라 $3.349\;{\times}\;10^{-10}{\sim}3.871\;{\times}\;10^{-10}\;g{\cdot}m/m^2{\cdot}s{\cdot}Pa$로 증가하여 다른 중성이나 알칼리성에서 추출한 분리 대두 단백질 필름에 비해 낮은 수증기 투과도를 보여, 산성에서 추출한 분리단백질로 제조한 가실성 필름이 다른 pH영역에서 추출한 SPI로 제조한 필름보다 강한 인장강도와 우수한 수분차단력을 보였다. 가소제의 농도가 증가함에 따라 $SPI_2$로 제조한 가식성 필름의 인장 강도는 가소제의 농도가 0.2 g plasticizer/g $SPI_2$에서 0.8 g plasticizer/g $SPI_2$로 증가함에 따라 가소제가 glycerol인 경우 12.297 MPa에서 1.356 MPa로, propylene glycol인 경우 7.408 MPa에서 2.147 MPa로, polyethylene glycol인 경우 10.579 MPa에서 2.987 MPa로 감소하여 가소제의 종류 및 농도를 달리함으로써 필름의 기계적물성을 조절하는 것이 가능하였다. 산성 영역에서 추출한 분리 대두 단백질($SPI_2$, $SPI_3$)이 다른 것들에 비해 단백질 함량과 11S/7S의 함량비가 높게 나타났으며, 이는 가식성 필름의 물리적 성질의 변화의 주요한 인자로 생각되고 있다.

• 멤브레인
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• 제26권2호
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• pp.126-134
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• 2016

바이오 가스로부터 바이오 메탄을 생산하기 위해 물리흡수제 특성평가 및 $CO_2/CH_4$흡수 연구를 진행하였고, poly-propylene(PP) 중공사막 막접촉기에 적용해보았다. 물리흡수제 중 propylene carbonate (PC)는 PP 중공사막과 가장 높은 $58.3^{\circ}$ 접촉각을 보였고, 5 wt% PC를 물과 혼합할 경우 $90^{\circ}$ 이상의 접촉각이 관찰되었다. 또한 $CO_2$ 흡수실험에서 PC/물 혼합 흡수제는 물 흡수량(0.121 mmol/g) 보다 높은 0.148-0.157 mmol/g의 흡수량을 보이며, 막접촉기에 가장 적합한 물리흡수제로 선정되었다. PC/물 혼합 흡수제를 막접촉기에 적용 후 얻어진 $CO_2$ 제거율(98.0-97.8%)과 $CH_4$ 순도(98.5-98.3%)는 바이오 메탄으로서 매우 높은 가능성을 보여주었다. 하지만 PC/물 혼합 흡수제의 경우에는 물 흡수제와 비교하여 성능 변화가 매우 미비하였다. 이는 물보다 우수한 PC 흡수능과 함께 그에 따른 막접촉기 탈기 막 모듈 및 시스템 개선과 공급 유량 조절을 통해 $CH_4$ 손실 최소화 등 공정 최적화가 필요한 것으로 분석된다.

• Journal of Microbiology and Biotechnology
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• 제26권1호
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• pp.72-79
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• 2016

The fungal morphologies and pellet sizes were controlled in acetophenone reduction by Rhizopus oryzae. The acetophenone conversion and (S)-phenylethanol enantiomeric excesses (e.e.) reached the peak after 72 h of incubation when using pellets with 0.54 mm diameter, which showed an excellent performance compared with suspended mycelia, clumps, and pellets with 0.65 or 0.75 mm diameter. Furthermore, nano-sized acetophenone was used as a substrate to improve the performances of biotransformation work. The results showed that the conversion of nanometric acetophenone and (S)-phenylethanol e.e. reached the maximum (both >99%) after 32 h of incubation when using 0.54 mm diameter pellets, at least 24 h in advance of the control group. On the other hand, Tween 80 and 1, 2-propylene glycol showed low or no toxicity to cells. In conclusion, pellets and acetophenone nanoemulsions synergistically result in superior performances of acetophenone reduction.

• 설비공학논문집
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• 제17권7호
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• pp.635-641
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• 2005

This study experimented to understand the effects of transporting ice slurry through elbow and inclined tube. And at this experiment it used propylene glycol-water solution and a diameter of about 2mm ice particle. The experiments were carried out under various conditions, with velocity of water solution at the entry ranging from 1.0 to 3.5 w/s and elbows and inclined tubes of 4 kinds angle with $30^{\circ},\;45^{\circ},\;90^{\circ}\;and\;180^{\circ}$. The pressure drop between the tube entry and exit were measured. According to angle of bending, the highest pressure drop was measured at $30^{\circ}$ elbow and the lowest pressure drop was measured at $90^{\circ}$ elbow, and there are only a little differences of pressure drop between $45^{\circ}$ elbow and $180^{\circ}$ elbow. According to angle of inclined tube, the highest pressure drop was measured at $90^{\circ}$ inclined tube and the pressure drop at $45^{\circ},\;30^{\circ},\;180^{\circ}$ inclined tubes were lower successively. The lowest pressure drop in elbows and inclined tubes was measured at velocity of $2.0\~2.5$ m/s and concentration of $10\;wt\%$.