• Journal of the Korean Institute of Gas
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• v.23 no.3
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• pp.40-45
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• 2019

Flash point is the important flammability indicator characterizing the risk of fire and explosion of flammable liquid mixture. In this study, flash points of water+formic acid and water+acrylic acid were measured by Seta flash apparatus. The flash points estimated by the methods based on empirical equation and Raoult's law were compared with experimental flash points. Absolute average errors of the results estimated by Raoult's law are $10.7^{\circ}C$ and $4.8^{\circ}C$ for water+formic acid and water+acrylic acid, respectively. Absolute average errors of the results estimated by empirical equation are $1.0^{\circ}C$ and $0.5^{\circ}C$ for water+formic acid and water+acrylic acid, respectively. In conclusion, the estimated values by empirical equation simulated the measured values better than those calculated by Raoult's law.

• KSBB Journal
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• v.31 no.1
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• pp.85-89
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• 2016

Lactic acid fermentations were conducted using water hyacinth. It is known that the pretreatment and enzyme hydrolysis process optimize the potential of water hyacinth. Lactic acid produced by using lactic acid bacteria. All cells were grown at $37^{\circ}C$ and initial pH 5.5. Lactic acid production was measured by HPLC. All Lactobacillus strains could produce lactic acid from pretreated water hyacinth. The highest lactic acid was achieved when lactic acid fermentation was carried out by L. delbrueckii for D-form and L. helveticus for L-form lactic acid production. The lactic acid concentration was 10.70 g/L by L. delbrueckii and it converted glucose in the medium to lactic acid, almost perfectly. Lactic acid production became higher when fermentation was carried out at a controlled pH 5.5. Lactic acid yield and productivity were 0.52 g/g and 0.19 g/L/h for L. helveticus, while L. delbrueckii was 0.64 g/g and 0.27 g/L/h. This study showed that water hyacinth medium could be alternative medium which can replace the complex and expensive medium for growing Lactobacillus strains in production of lactic acid.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.243-245
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• 2002

Brackish water desalination using reverse osmosis(RO) membrane is more useful and economic than sea water to solve the shortage of fresh water supply because of its low total dissolved solid(TDS) contents. Silica and humic acid in brackish water make serious fouling problems and cause the decline of permeate flux and increase of operating pressure. In this study, the experiments for removal of silica and humic acid were conducted with calcite particles to prevent membrane fouling and investigated the effect of pH of feed water Adsorption of silica to calcite was higher at pH=7.5 than 9.5 and removal rate was increased according to increase of initial concentration of silica. The effect of pH on adsorption of humic acid was not significant but at low initial concentration the adsorption of humic acid was enhanced at pH 7.5. The result of this study expect to apply to brackish water desalination experiment of flat-sheet reverse osmosis membrane.

• The Korean Journal of Ecology
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• v.21 no.2
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• pp.117-124
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• 1998

To clarify the effects of acid precipitates on histological damage, water status, and growth of Pinus densiflora green house experiment applyin simulated acid rain was carried out. Contact angle of water droplet on needles of P. densiflora seedlings treated with simulated acid rain of different pHs simulated acid rain was, the more rapid transpiration was. Leaf water potential after water withdrawal was also reduced rapidly in proportion to acidity of simulated acid rain. Height growth of P. densiflora seedlings treated with simulated acid rain of pH 2 decreased, while growth of seedlings treated with that of pH 3 and 4 increased comparing with that treated with normal rain of pH 5.6. pH of cultivated soil in pH 2 plot was acidified with the amount of simulated acid rain applied but that in pH 3 and 4 plots did not show any directional change. From those results, it could be interpreted that decrease of height growth in pH 2 plot was originated from multiple effects of water deficit from rapid transpiration and soil acidification. On the other hand, increased of height growth in pH 3 and 4 plots would be originated from the supply of N and S included in simulated acid rain.

• Korean journal of food and cookery science
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• v.28 no.4
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• pp.443-450
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• 2012

This study was investigated the effect of an oil-water fryer on quality properties of deep frying oil used for chicken. The acid and conjugated dienoic acid values of frying oil using an oil-water fryer were lower than those using a deep fat fryer, whereas the iodine value of frying oil using an oil-water fryer was higher than that using a deep fat fryer. The peroxide values of frying oil did not increase with frying number. Frying oil with an oil-water fryer had lower palmitic acid, stearic acid and oleic acid, and higher linoleic and linolenic acid contents than those with a deep fat fryer. The contents of trans-fatty acids in frying oil using a deep fat fryer and oil-water fryer after frying 110 chickens were 0.75% and 0.47%, respectively. The benzopyrene contents of frying oil using a deep fat fryer and an oil-water fryer after frying 110 chickens were 2.20 and $1.61{\mu}g/kg$, respectively.

• Journal of Sericultural and Entomological Science
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• v.33 no.2
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• pp.100-102
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• 1991

The features of waste water from by-product silk treatment of silk reeling process were investigated and the lipid extracted from waste water was analysed. The COD of waste water from by-product silk treatment was at the level of 605 mgO/$\ell$ Total Dissolved Solid Particles 2,335mg/$\ell$and Total Suspended Solid Particles 2,123mg/$\ell$. The lipid extracted from the waste water from by-product silk treatment was composed of triglyceride 76.8%, free fatty acids 12.5%, diglyceride 5.7% and free sterol 5.0%. In fatty acid composition of lipid, the content of loeic acid, linoleic and linolenic acid was 64.93%, whereas that of palmitic acid was 29.39% and stearic acid 4.93%.

• Journal of the Korean Applied Science and Technology
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• v.8 no.1
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• pp.79-83
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• 1991

The extracts of Quercisemen(Quereus acutissima Carruthers seed) powder was obtained by the extraction with distilled water, water : acetonet(1:1, v/v), ethanol and ethyl ether, respectively. As a result this experiment, the antioxidative activity of each solvent extracts on linoleic acid were examined as follows: 1. Each fraction extracted by the acetone : water(1:1, v/v), water and ethanol respectively showed high antioxidative activity. 2. A fraction of the tannin extracted from the solvent, acetone, water(1:1, v/v) showed even more antioxidative activity than that of the ${\alpha}$-tocopherol or BHT. 3. Acceleration of peroxide reaction by $Fe^{++}$ and $Cu^{++}$ on the linoleic acid was strongly inhibited by adding the tannin, 4. Organic acid, such as malic acid, citiric acid and tartaric acid with the tannin were showed the synergistic effect fo the antioxidation reaction.

• Korean Journal of Plant Resources
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• v.12 no.1
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• pp.10-19
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• 1999

The water status of Pinus densiflora and P. koraiensis was observed after the treatment of simulated acid rain for every month August 1997 to March 1998. Both of the species showed increase of dry weight, water saturation deficit and epidermis transpiration after treatment of simulated acid rain (pH 3.5) for first three months. On the contrary, water content was decreased in both the species after three month of simulated acid rain treatment. The effect of simulated acid rain, however, became weaker after that and no big difference was observed after seven month of treatment. Water potential of the leaf of both species became lower than that of the control(pH 5.6) after seven month treatment of simulated acid rain. The cuticle layers of the epidermis and florins ring were damaged seriously and the size of the gap between stomata became bigger after the treatment of simulated acid rain.

• Membrane and Water Treatment
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• v.7 no.2
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• pp.101-113
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• 2016

In this study, to improve the water flux of porous hydrophobic membranes, various water-soluble polymers including neutral, cationic and anionic polymers were adsorbed using 'salting-out' method. The adsorbed hydrophobic membrane surfaces were characterized mainly via the measurements of contact angles and scanning electron microscopy (SEM) images. To enhance the durability of the modified membranes, the water-soluble polymers such poly(vinyl alcohol) (PVA) were crosslinked with glutaraldehyde (GA) and found to be resistant for more than 2 months in vigorously stirred water. The water flux was much more increased when the ionic polymers used as the coating materials rather than the neutral polymer and in this case, about 70% of $0.31L/m^2{\cdot}h$ (LMH) to 0.50 LMH was increased when 300 mg/L of polyacrylamide (PAAm) was used as the coating agents. Among the cationic coating polymers such as poly(styrene sulfonic acid-co-maleic acid) (PSSA_MA), poly(acrylic acid-comaleic acid) (PAM) and poly(acrylic acid) (PAA), PSSA_MA was found to be the best in terms of contact angle and water flux. In the case of PSSA_MA, the water flux was enhanced about 80%. The low concentration of the coating solution was better to hydrophilize while the high concentration inclined to block the pores on the membrane surfaces. The best coating condition was found: (1) coating concentration 150 to 300 mg/L, (2) ionic strength 0.15, (3) coating time 20 min.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.2
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• pp.172-175
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• 1988

Composition of fatty acids and amino acids in water extracted material of cooks comb plant root was studied by HPLC and GC-MS. There are 14 kinds of fatty acids in water extracted material of cockscomb plant root, especially, hexadecadienoic acid$(C_{16:2})$ was contained. Tricoasnoic acid, lignoceric acid, cerotic acid and 1,1'-[3-(2-cuclopentylethyl:dene)-1,5-pentanediyl] bis-cyclopentane were identified by HPLC and GC-MS. There are 16 kinds of acids containing ${\alpha}-aminobutyric$ acid in water extracted material of cockscomb plant root.