• 한국해양학회지
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• v.7 no.1
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• pp.24-45
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• 1972

The Han River is an important water source in Seoul and neighbouring districts, for public and industrial supply, and for agriculture and fishery. Nowadays, more than six million inhabitants are supplied withe water from this river. The total length of the river is 470km, and has 17 10$\^$9/㎥ an average annual flow. The hydrographic characteristics at Seoul are 653㎥/sec in an average flow, 4,608㎥/sec in the maximum average flow, and 201㎥/sec in the minimum average flow. These are influenced in some degree by snowmelt in early spring, and greatly by the flood during summer. For the pollution problems, the periods of low flow are critical ones. As a rule they occur around the months November through June. Nowadays, most of the sewage from towns and industries is discharged untreated. Apart from domestic and industrial sewages, there are some discharges of mineral matter by mines in the upriver region. In general, water quality of the Han River is kept very clean and healthy until Kwangnaru of the upper region of Seoul. A large pollution, however, is received in the downstream by the domestic and industrial sewages of Seoul. It can be seen that dissolved oxygen, COD and BOD$\sub$5/ diminish markedly, and the intensity of almost every water parameter of the river continues to increase. Comparison of the figures for 1971 derived from a sampling point 40km downstream of Kwangnaru leads to the conclusion that hardness, Ca and Mg were no changed; alkalinity, Si and soluble- Fe were slightly increased; CO$\sub$2/, acidity, Cl, NO$\sub$2/-N, Cu, Zn and Al were increased in 2 and 3 times; total residue, total ignitious residue, COD, BOD$\sub$5/, NH$\sub$4/-N, PO$\sub$4/-P, Mn, Pb and total-Fe were increased in 4 to 7 times; and SO$\sub$4/, particulate-Fe and Cd were increased in 10 to 11 times. On the other hand, coliforms were increased in 650 times; fecal coliforms in 365 times; enterococci and total plate counts in 30 times, respectively. In view points of water quality standards, the down Han River water is now leveling out in Cd, coliforms and fecal coliforms for the agricultural use; in dissolved oxygen and some trace elements (Cu, Zn, Pb and Cd) for the fishery use; in ammonia, COD, BOD$\sub$5/, and Cd for the drinking use.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.705-711
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• 2015

This study was conducted to maintain the postharvest shelf-life of summer strawberry cultivars 'Goha' and 'Flamengo' through $CO_2$ (90%) and $ClO_2$ gas ($5{\mu}L{\cdot}L^{-1}$) pre-treatment. The respiration rate of 'Goha' and 'Flamengo' treated with $CO_2$ and $CO_2$ + $ClO_2$ was the lowest during storage. The weight loss with $CO_2$ + $ClO_2$ treatment was about 1% lower than the control group and 'Goha' was the lowest during storage. The pre-treatments effect on soluble solids contents was minimized. The firmness with $CO_2$ and $CO_2$ + $ClO_2$ treatments was only about 30% higher than $ClO_2$ and control. The firmness of 'Goha' was about 2.15N and 'Flamengo' was 2.37N, 15 days after storage. Decayed fruit was shown from after 6 days after storage in control. Control group lost quality 10 days after storage due to decayed fruit rate 20% of 'Goha' and 'Flamengo'. $CO_2$ and $CO_2$ + $ClO_2$ treatments showed the lowest decay rate during storage. Especially, 'Goha' showed around 5% decay fruit rate 10 days after storage. As a result, $CO_2$ + $ClO_2$ pre-treatment is recommended to extend the shelf-life of the summer strawberries.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.4
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• pp.303-313
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• 2015

Titrated extract of Centella asiatica (TECA), which is poorly soluble in water is well known for wound healing and anti wrinkle agent. This study was conducted to find the optimum condition for the preparation of water in oil in water ($W_1/O/W_2$) emulsion containing TECA. Solubility of TECA were measured by UV spectrophotometer. 2.55 g of TECA was dissolved in solution composed of dipropylene glycol (40.0 g), ethanol (20.0 g), and water (10.0 g). Factors affecting stability of the emulsions ($W_1/O$, $W_1/O/W_2$) was investigated. The optimum conditions for the preparation of $W_1/O$ emulsion was composed of dipropylene glycol : ethanol : water : TECA in a weight ratio of 40.0 : 20.0 : 10.0 : 2.5 for water phase and squalane : cetyl PEG/PPG-10/1 dimethicone : cetearyl alcohol in a weight ratio of 22.5 : 4.0 : 2.5 for oil phase. The optimum conditions for the preparation of $W_1/O/W_2$ multiple emulsion was composed of water : $W_1/O$ emulsion : polysorbate 80 : carbomer : triethanolamine in a weight ratio of 55.8 : 40.0 : 4.0 : 0.1 : 0.1.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.272-281
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• 2023

It has been known that Paeoniae Radix (PR) contains monoterpene glycosides showing a variety of biological activities such as anti-spasmodic, anti-inflammatory, anti-viral, neuroprotective, and sedative effects. This study aimed to find the cytotoxic compounds isolated from the dichloromethane (CH₂Cl₂)- and ethyl acetate-soluble fractions of PR. As results, thirteen compounds (1-13) were isolated and the chemical structures were identified. In addition, the human alveolar adenocarcinoma cell line (A549) was treated with isolated compounds to determine the cytotoxic effect via evaluation of cell viability. The reduction of A549 cell viability was shown as following order; gallic acid (8) > (2S)-naringenin (9) > methyl gallate (10)>6'-O-benzoylpaeoniflorin (7) > palmitic acid (3). Especially, 7 did not show the cytotoxicity in the human lung fibroblast cell line (MRC-5). The effect of 7 on the cell viabilities in A549 and MRC-5 is firstly reported in this study. Further study is required to find out the cytotoxic mechanism and the selectivity for the cancer cells of 7 in detail.

• Journal of Life Science
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• v.26 no.5
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• pp.545-554
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• 2016

Hyaluronic acid (HA) is an important macromolecule in medical and pharmaceutical fields. HA is a natural and linear polymer composed of repeating disaccharide units of β-1, 3-N-acetyl glucosamine and β-1, 4-glucuronic acid. This work aimed to confirm the structural characteristics and anti-inflammatory activities of HA and its chemically sulfated-HA. HA was produced from a fed-batch fermentation process using Streptococcus dysgalactiae in a 5 l bioreactor. HA was isolated water-soluble form (HA-WS) and water-insoluble form (HA-WI) from culture medium, and was obtained chemically sulfated-derivative (S-HA) that resulted in a 90% yield from HA-WI. The structural features of the sulfated- HA (S-HA) were investigated by FT-IR and ¹H-NMR spectroscopy. The FT-IR and NMR patterns revealed the similarity in both the FTIR spectrum as well as NMR spectrum of both reference standard and purified HA from S. dysgalactiae. The anti-inflammatory activities of HA and S-HA were examined on LPS-induced RAW 264.7 cells. S-HA was significantly inhibited production of pro-inflammatory mediators such as nitric oxide (NO) and PGE₂ and the gene levels of iNOS and COX-2, which are responsible for the production of NO and PGE₂, respectively. Furthermore, S-HA also suppressed the overproduction of pro-inflammatory cytokine TNF-α (<80 pg/ml) and IL-6 (<100 pg/ml) compared to that of HA-WI. The present study clearly demonstrates that HA-S exhibits anti-inflammatory activities in RAW 264.7 macrophage cells.

• Macromolecular Research
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• v.11 no.6
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• pp.501-505
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• 2003

Poly(l,6-heptadiyne) derivatives with phenoxy and 3,7-dimethyloctyloxyphenoxy substituents were synthesized using metathesis polymerization. Polymerizations using MoCl$\sub$5/ as the sole catalyst gave high yields and the resulting polymers were completely soluble in organic solvents. The polymers' structures and thermal properties were characterized using NMR and UV-Vis spectroscopy, as well as with TGA and DSC thermograms. From the analysis of the high-resolution $\^$13/C-NMR spectra, we was found that these polymers contain six-membered rings. The number-average molecular weights and polydispersities of the polymers were ca. 7.0∼20 ${\times}$ 10$^3$ and 3.1∼5.8, respectively. The glass transition temperatures of the polymers were found to be in the range 91∼159$^{\circ}C$.

• Textile Coloration and Finishing
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• v.13 no.6
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• pp.413-427
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• 2001

In this studs, we synthesized durable antistatic agents with acrylic monomers for preventing the electrification of static electricity which is one of defects of polyester fabrics. Also we synthesized quaternary ammonium salts which give antistatic property and crosslinking agents which make antistatic agents adhere to fiber. The treatment of synthesized antistatic agents on polyester fabric carried out at the condition of various concentrations, treatment times and temperatures. The antistatic property, handle characteristics and other properties of treated and untreated polyester fabrics were also investigated.

• Textile Coloration and Finishing
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• v.17 no.1
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• pp.45-51
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• 2005

Soluble keratose(S-keratose) could be obtained by oxidizing the wool keratin with performic acid. S-keratose/PVA solutions were made by dissolving them in the formic acid and S-keratose/PVA web of sub-micron size was made by electro-spinning technique. SEM, elemental analysis, FT-IR, X-ray diffractometry, and TGA were used to characterize the properties of S-keratose/PVA solutions and fibers. As the S-keratose content in S-keratose/PVA solution increased, viscosity of solution decreased while electrical conductivity has increased. The fiber diameter has decreased with increasing the S-keratose content. S-keratose/PVA ratio in fibers were similar to the ratio in the solutions. The crystalline structures of S-keratose and PVA existed separately in the electrospun webs. Thermal stability of the web increased with the PVA content increasing.

• Textile Coloration and Finishing
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• v.17 no.1
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• pp.38-44
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• 2005

Oxidation method was used to extract S-keratose from wool. Wool was treated with performic acid and soluble fraction(S-keratose) was collected by evaporating the solvent. S-keratose and Nylon 6 were dissolved in formic acid at the ratio of 100/0, 80/20, 50/50, 20/80, and 0/100, and S-keratose/Nylon 6 web of sub-micron size was made by electro-spinning technique. SEM, EA, FT-IR, XRD, and TGA were used to characterize the properties of S-keratose/Nylon 6 solutions and electrospun fibers. As the Nylon 6 content increased, viscosity, conductivity of the electrospinning solution and the diameter of spun fiber increased. Electrospun nonwoven webs have the same S-keratose/Nylon 6 ratios of the spinning solutions. The crystalline structures of S-keratose and Nylon 6 existed separately in the electrospun webs. Thermal stability of the webs increased due to Nylon 6 content.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.896-898
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• 2009

The printed electrodes of organic thin-film transistors (OTFTs) were fabricated by screen printing using nanoparticle silver pastes. The screen printed OTFT corresponds to channel lengths between 7.6 to 82.6 ${\mu}m$ (designed L=10 to 80 ${\mu}m$) on the $150{\times}150mm^2$ paper. The channel length deviations for 40 to 80 ${\mu}m$ patterns were less than 5 %. However, the channel lengths for 10 to 30 ${\mu}m$ patterns were increased by 20 %. The screen printed bis(triisopropyl-silylethynyl) pentacene (TIPS-pentacene) OTFTs obtained had a field-effect mobility as large as 0.08 (${\pm}0.02$) $cm^2$/Vs, an on/off current ratio of $10^5$ and a subthreshold slope of 1.95 V/decade.