• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.3
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• pp.23-28
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• 2022

In order to investigate the degree of sewage sludge dewaterability using Fe(II)/Na₂S₂O₈, STTF, SCST, water content, TS, VS, TB-EPS as carbohydrate and Protein were measured. The dosage of Na₂S₂O₈ was varied from 0.4 to 0.7 mmol/gVS and molar ratio of Fe(II)/Na₂S₂O₈ was varied from 0.5 to 0.7 mol/mol. According to the increase of the dosage of Na₂S₂O₈ and Fe(II)/Na₂S₂O₈ molar ratio, STTF and SCST increased from 1.00 to 15.00 and 4.51, respectively. Water content decreased to 82.6%. TB-EPS as carbohydrate and protein decreasing rate also increased to 37.16% and 57.34%, respectively. Especially, Na₂S₂O₈ 0.6 mmol/gVS and Fe(II)/Na₂S₂O₈ 0.6 mol/mol condition, water content dercreased to 83.1%, STTF and SCST increased to 13.64 and 4.19 which showed the cost effective improvement of dewaterability. It is considered that SO₄^- radical generated by Fe(II)/Na₂S₂O₈ degraded EPS and converted bound water to free water.

• Journal of Adhesion and Interface
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• v.24 no.1
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• pp.26-35
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• 2023

Generally, solvent-type coatings generate a large amount of volatile organic chemicals(VOC), which are carcinogenic substances, in the manufacturing process, and their use is regulated due to environmental problems. There is also the problem of resource depletion due to limited fossil fuels. Therefore, in this study, UV-curable urethane acrylate oligomers were synthesized with different contents of isosorbide, which is a biomass material, and proceeded to evaluate the physical properties of coatings. As the isosorbide contents increased, the viscosity, glass transition temperature, tensile strength, stain resistance, and pencil hardness increased, but elongation and flexibility decreased, and BOI-3 showed the best adhesion. The isosorbide content of the oligomer fixed at 20%, UV-curable urethane acrylate oligomer was synthesized according to the content ratio of polycaprolactone diol(PCL) and Ecoprol H1000(Ecoprol). As the PCL/Ecoprol content ratio increased, the glass transition temperature, elongation, and flexibility increased, but the tensile strength and pencil hardness decreased. It was confirmed that the adhesion and stain resistance increased by improving the surface bonding strength of PCL. All films of oligomers synthesized were transparent without discoloration.

• Composites Research
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• v.36 no.5
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• pp.349-354
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• 2023

Poly(3-hexylthiophene) (P3HT) is a conjugated polymer that is highly soluble in organic solvents and is readily available. However, its electrical properties as an active channel in electronic devices are not enough for practical applications, necessitating further improvement in the properties. In this study, we demonstrate that the blending of two P3HT polymers (i.e., regio-regular (RR) P3HT and regio-random (RRa) P3HT) with different regioregularities can significantly improve charge transport characteristics of the blend films. The morphological and electrical properties of the blend films were systematically investigated by varying the ratio between two P3HT polymers. Atomic force microscopy (AFM), X-ray diffraction (XRD), and UV-visible absorption spectroscopy (UV-vis) were employed to evaluate the morphological and optoelectronic properties of the blend films. The crystallinity of the blend films increased with increasing the content of RRa-P3HT to 20 wt% and gradually decreased as the content increased to 80%. Consistently, the highest charge carrier mobility was obtained from the blend films containing 20 wt% RRa-P3HT, which value was measured to be 0.029 cm²/V·s. The values gradually decreased to 0.0007 cm²/V·s with increasing the content of RRa-P3HT to 80 wt%.

• Proceedings of the Ginseng society Conference
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• 1990.06a
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• pp.102-110
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• 1990

Antitumor polyacetylenlc alcohol, panaxytriol (Ci7 H2603), was isolated and purified from a Powder of the root of Panax ginseng C.A. Meyer. Panaxytriol Possesses unusual Property of being soluble in both water and organic solvents. Panaxytriol inhibited the growth of various kinds of human cultured cell lines in dose-dependent fashion in vitro. The in vivo effects of panaxytriol were tested against C57BU6 mice transplanted with Bl6 melanomas. Panaxytriol (8 and 40 mg/kg) administered intramuscularly (im) produced significant tumor growth delays in mice. Although a detailed mechanism of growth inhibition by panaxytriol is unknown, preliminary results appear to implicate a surface membrane site of action. And its action seems to be more dose-dependent than time-dependent. Finally, panaxytriol pharmacokinetics was evaluated in mice given single 8 mgrkg doses intraperitoneally(ip) or im. Serum panaxytriol content was measured using both tumor growth inhibitory assay and a gas chromatographic method. The maximum serum panaxytriol content after ip and im administration was 35.0 and 1.61 ug/ml respectively. These results indicate that the compound may act as cytotoxic substance even in-patients. Keywords Panax ginseng, panaxytriol, tumor growth inhibition

• Journal of Ginseng Research
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• v.4 no.2
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• pp.165-174
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• 1980

The concentrated red ginseng extract (RGE) which was prepared from water extract of red ginseng tails was investigated for its changes in color intensity, sugar contents and during storage at various temperatures. In order to evaluate the color of RCE, a spectrophotometric measurement in ultraviolet and visible range was applied. The concentrated RGE was divided into three fractions of aqueous, butanol and benzene layers. It was found that : (1) Increase in RCE color during heat treatment was considered to be due to nonezymatic browning reaction. Water soluble layer showed approximately 100 times higher color intensity than those of organic solvent layers (2) The RCE stored at 8$0^{\circ}C$ showed an increase in fructose and glucose content while a rapid decrease was resulted at 10$0^{\circ}C$. (3) A rapid increase in absorbances at 400 and 460nm was shown at 90 and 10$0^{\circ}C$ after an initial induction period and slowed down after 50 hours . (4) A significant relationship was found between decrease in sugar content and increase in color intensity. (5) Absorbance ratio of 400nm/460nm indicated that benzene layer has about two times higher value in violet color than those of butanol and aqueous layers.

• Preventive Nutrition and Food Science
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• v.1 no.2
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• pp.159-167
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• 1996

Effect of covering various levels(0, 1, 3, 5 and 7% per Chinese radish weight) of bamboo(Pseudosasa japonica Makino) leaves on the surface of Dongchimi was studied in the course of fermenting at 1$0^{\circ}C$ up to 75 days. Physicochemical, microbiogical, and sensory characteristics of Dongchimi were analyzed at regular intervals of 5 to 7 days during fermentation. Both the degree of pH drop from the initial 6.47~6.54and increase total acid content from the initial 0.004%, with the accumulation of organic acids tended to be more gradual depending upon the amounts of bamboo leaves covered. The increases of total solid content and turbidity were also suppressed in similar patterns, notably after 13 days of fermentation. The growth of total bacteria(1.5$\times$10$^4$cfu/ml, initial)was partly inhibited while that of lactic acid bacteria(1.8$\times$10$^4$cfu/ml, initial)was favorably encouraged by the presence of bamboo leaves. As a result of sensory evaluation, Dong-chimi covered with 1 and 3% bamboo leaves on showed the higher scores significantly(p<0.05, p<0.01, p<0.001) in overall acceptability till 39 days. But after 61 days, those covered with 3 and 5% bamboo leaves were rather preferable than any other one.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.4
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• pp.737-740
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• 1992

This study was conducted to demonstrate the practical use of the buffer index curve as a criterion of silage quality evaluation, Forty five samples of the ensiled Italian ryegrass were collected from farms in Okayama, Japan. Silages were devided into 4 groups by the pattern of buffer index curve. Heavy wilting silages (A group) showed no peak on buffer index curve and Flieg's score of 95.6. However, moderate or weak wilting silages (B group) with moisture content of 63.3 showed a peak at pH 4.0 and a Flieg's score of 67.8. Both of A and B groups were regarded as a good quality silage. Silages (C group) with a peak at pH 4.5 were of a medium quality with Flieg's score of 45.3. Poorly preserved silages (D group) with Flieg's score of 12.0 had a peak at pH 5.0. There was a high positive correlationship (p<0.01) between the peak value of buffer index curve and the organic acid content.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.11
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• pp.1560-1568
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• 2011

This study was conducted to evaluate the yield, nutrient characteristics, ruminal solubility, degradability and disappearance of spent mushroom (Agaricus bisporus) substrates for ruminants. The annual yield of spent Agaricus bisporus substrates was measured to be about 210,000 tons (M/T) in South Korea. The surface soil-removed spent substrates had nutritional characteristics of high crude ash (375 g/kg) and Ca (32 g/kg), medium protein (134 g/kg CP), and high fiber (384 g/kg NDF on a DM basis). Compared with initial mushroom substrates, spent mushroom substrates had twice higher (p<0.0001) CP content and 22.0% lower (p<0.0001) NDF content on an organic matter basis. Compared with raw rice straw, spent rice straw had much higher (p<0.05) predicted ruminal degradabilities and disappearances of DM and CP and a little lower (p<0.05) predicted degradability and disappearance of NDF. In conclusion, the general feed-nutritional value of spent mushroom (Agaricus bisporus) substrates appeared to improve after cultivation of mushrooms.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.529-532
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• 2001

Korean food waste, one of the abundantly available but environmentally problematic organic wastes in Korea, was utilized as solid-substrate by fungal strain Aspergillus niger ATcC 6275 for the production of enzymemixture containing amylase, cellulase and xylanase. The enzyme mixture can be used as high value-added animal feed. Solid-state fermentation method yielded a 84-fold enhancement in xylanase activity compared with submerged fermentation method. The effect of incubation period, incubation temperature, pH of medium, moisture content, inoculum size and enrichment of the medium with nitrogen and carbon sources were observed for optimal production of these enzymes The optimal amylase activity of 33.10 U/g, cellulase activity of 24.41 U/g, xylanase activity of 328.84 U/g were obtained at 8 days incubation with 50%(w/w) soy bean flake, with incubation temperature of $25^{\circ}C$, pH of 6.38, optimal moisture content of 55% and with inoculum size of $3.8{\times}10^6$spore/g. Enzyme activities were enhanced when ImM $CaSO_4$, 2% Malt extract and 2% galactose were added as mineral, nitrogen and carbon enrichment respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.1
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• pp.40-46
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• 1988

This study was carried out to determine the effects of nitrogen (N) fertilization levels (0, 100 and 200kg/ha) and formaldehyde (0.4,0.8 and 1.2%: w/w CM) on the chemical composition, dry matter (DM) yield and in-vitro dry matter digestibility (IVDMD) of forage rape (Brassica napus Subsp. oleifera) silage. The results obtained are summarized as follows : 1. Forage rape was a catch crop which was highly digestible and low concentration in NDF, ADF, cellulose and lignin. 2. The concentration of the water soluble carbohydrate (WSC) and buffering capacity (PK) was 17.9% and 6.77g/100g, respectively, provided the WSC to PK ratio was 2.65. 3. DM content of silage decreased as the rate of N fertilization increased, but concentration of ammonia-N decreased. IVDMD was not affected by the rate of N fertilization. 4. By the addition of formaldehyde, the pH and IVDMD were increased, but the DM, lactic acid, total organic acid and ammonia-N content of rape silage were decreased, that was effective as a silage additive for forage rape.