• YAKHAK HOEJI
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• v.40 no.3
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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.

• Proceedings of the SCSK Conference
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• 2003.09b
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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.

• Journal of Navigation and Port Research
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• v.35 no.5
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• pp.365-370
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• 2011

The ice-thermal energy storage cooling system has been applied to relief a significant portion of the peak demand of electricity during the daytime in summer. Slurry ice type system is one kind of ice-thermal storage cooling system utilizing cheaper off-peak electricity. This study is experimented to observe an influence of experimental conditions on production characteristics of slurry ice by using reversing flow, which is putting reversing material into test section to disturb ice adhesion. At this experiment, poly propylene ball of dimeter 10 mm was used as reversing material, and ethylene glycol-water solution of 20wt% concentration was used as flow material. The experimental apparatus was constructed of the slurry ice making and storage tank(test section), the brine tank, pumps for ethylene glycol-water solution and brine circulating, a mass flow-meter, data logger for fluid temperature measuring. The experiments were carried out under various conditions, with volumetric flow rate, ball filling rate and air filling rate.

• Journal of Integrative Natural Science
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• v.14 no.3
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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.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.149-154
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• 2011

In order to explore properties of various rubber compounds after thermal aging under the condition similar to the operating environment of a fuel cell-stack, heat resistance and compression set of those compounds were investigated for a long term operation in $H_2SO_4$, $H_2O$, and LLC (ethylene glycol : $H_2O=50:50$) solution. It was assumed that aging Acrylonitrile butadiene rubber (NBR) and Elthylene Propylene diene rubber (EDPM) compound in the solution resulted in discoloration as time passed. It was also found that hydrolysis was developed on the Silicone rubber (VMQ) compound intentionally aged under acidic condition by means of TGA, SEM, and EDS analysis.

• Fisheries and Aquatic Sciences
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• v.24 no.2
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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.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.452-459
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• 1997

Effect of extraction pH on mechanical properties such as tensile strength (TS) and elongation (E) and on water vapor permeability (WVP) of soybean protein isolate (SPI) edible films extracted from soybean meal was investigated. Five pHs, acidic range (pH 2.0 and pH 3.0), neutral range (pH 7.0) and alkalic range (pH 10.0 and 12.0), were used to extract SPI. TS of the film extracted at pH 7.0 was the lowest, and WVP of $SPI_3$ (SPI extracted at pH 3) film was the lowest value among the films. The WVP of $SPI_3$ films was $3.349\;{\times}\;10^{-10}\;g{\cdot}m/m^2{\cdot}s{\cdot}Pa$ and increased to $3.871\;{\times}\;10^{-10}\;g{\cdot}m/m^2{\cdot}s{\cdot}Pa$ as film thickness increased from $55\;{\mu}m$ to $72\;{\mu}m$ thickness. Three different plasticizers (glycerol, polyethylene glycol and propylene glycol) were used for $SPI_2$ (SPI extracted at pH 2) film. TS of $SPI_2$ films was 12.297 MPa and decreased to 1.356 MPa for glycerol and showed the same trend in other two plasticizers. The SPI films extracted at acidic range were shown higher mechanical properties and lower water vapor permeabilities than those of extracted at neutral and alkalic ranges. The difference of SPI film properties seemed to be attributed by 11S/7S ratio as well as protein content.

• Membrane Journal
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• v.26 no.2
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• pp.126-134
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• 2016

To produce renewable biomethane from biogas, the properties of physical absorbents such as water, methanol, 1-methyl-2-pyrrolidone (NMP), poly(ethylene glycol) dimethylether (PEGDME), and propylene carbonate (PC) were studied, and PC was applied to membrane contactor systems. Among physical absorbents, PC exhibited a high contact angle of $58.3^{\circ}$ on polypropylene surface, and a PC/water mixture (5 wt%) increased the contact angle to $90^{\circ}$. Furthermore, the PC/water mixture presented higher $CO_2$ absorption capacities (0.148-0.157 mmol/g) than that of water (0.121 mmol/g), demonstrating a good property as an absorbent for membrane contactors. Actual operations in membrane contactors using the PC/water mixture resulted in $CO_2$ removal of 98.0-97.8% with biomethane purities of 98.5-98.3%, presenting a strong potential for biogas treatment. However, the PC/water mixture yielded moderate improved in $CO_2$ removal and methane recovery, as compared with water in the membrane contactor operation. This is originated from insufficient desorption processes to reuse absorbent and low $CO_2$ flux of the PC/water absorbent. Thus, it is requiring optimizations of membrane contactor technology including development of absorbent and improvement of operation process.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.7
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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 $10\;wt\%$.