• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.1
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• pp.97-102
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• 2000

This study was carried out to investigate the effects of operating temperatures on decomposition and physicho-chemical properties of household food wastes in a fermentation dryer, which was manufactured by Samwoo Co. Ltd. The household food wastes of 100 kg can be put and dried in this dryer at once. The experiments were performed at each temperature of $35^{\circ}C$, $45^{\circ}C$, $55^{\circ}C$ and $70^{\circ}C$ for two days respectively. The samples taken at the fixed time were dried at $105^{\circ}C$ and analyzed to find the decomposition rate and the concentration of each substance. The results obtained were as follows: The decomposition rate at 35 and $70^{\circ}C$ was the highest and showed the similar tendency during the experimental period. The higher the operating temperature was, the faster the water content of the composting material reduced. pH value increased at the operating temperature of 55 and $70^{\circ}C$ and was higher than at the other operating temperatures. Nitrogen content did not show any tendency during the experimental period. $P_2O_5$ and CaO content increased during the experimental period but MgO, $K_2O$ and NaCl were not accumulated. Cu content based on dry matter was in the range of ND~100.4 mg/kg and Cd, Pb and Cr were not detected.

• Journal of Adhesion and Interface
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• v.17 no.3
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• pp.110-116
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• 2016

A decrease in the retro-reflectivity of glass-bead-covered road paint because of a rainwater film significantly reduces the visibility of drivers at night, and has been considered as a critical cause of traffic accidents. For enhanced visibility, the microencapsulation of hydrophobically modified $SrAl_2O_4:Eu^{2+}$,$Dy^{3+}$ phosphorescent phosphor was carried out via suspension polymerization of methyl methacrylate (MMA). The effects of surface modification agent and radical initiator types, loading amount of phosphorescent phosphor, and microcapsule size on the phosphor content ($W_{TGA}$) in the luminous poly(methyl methacrylate) (PMMA) microcapsules were investigated by thermogravimetric analyses (TGA). It was found that the $W_{TGA}$ value was ranged from 7 wt% to 81 wt%, which suggests suspension polymerization is suitable for the preparation of luminous microcapsules with a wide range of phosphor content. At a lower loading amount of phosphor, the $W_{TGA}$ value obviously increased as the microcapsule size decreased; however, the $W_{TGA}$ values with a higher loading amount of phosphor were less affected by the microcapsule size. The luminous microcapsules with the size range of $425{\sim}710{\mu}m$ were collected and tested as a luminous road lanes. It was found that luminance intensities of the microcapsule-coated plates remained higher than $300mcd/m^2$ for up to 100 s in darkness after 20 min of light emitting diode lamp irradiation. The results suggest that the luminous microcapsules can be a candidate for the replacement of glass beads for enhanced visibility of drivers.

• Applied Biological Chemistry
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• v.25 no.4
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• pp.201-205
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• 1982

As a series of study on the removal of astringency and production of tannin substances, this experiment was conducted to investigate changes of tannin contents and microscopic observation on leaves of persimmon(Diospyros kaki L.). Changes of tannin contents of leaves and fruits in Daegu Bansi(astringent variety) were of similar tendency in content of total and soluble tannin during growth. It seemed therefore that tannin contents of leaves in astringent variety were closely concerned with tannin of fruits. But Fuyu(sweet variety) was different from each other during its growth. Histological form of leaves in microscopic observation had similar tendency between astringent and sweet varieties. It was observed that tannin substances were contained in epidermis cells of levels, that tannin substances were transfered in phloems of nerves system, and that tannin cell existed too in the vicinity of nerves system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.2
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• pp.84-92
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• 2020

For humans, soybean and soybean products are the main dietary sources of isoflvones, which are polyphenolic compounds that represent one of the most common categories of phytoestrogens. The objective of this study was to determine isoflavone concentrations in soybean cultivars during germination when treated with some biotic substances. Three soybean cultivars were germinated in replicated trials in 2018/2019 and their individual and total isoflavone concentrations were determined using HPLC (High-Performance Liquid Chromatography). Significant differences were observed in total isoflavone content were observed among cultivars regardless of years and treatments. 'Daepung2-ho' and 'Uram' had significantly higher total isoflavones than 'Pungsannaul-kong'. Differences among treatments were also significant for total isoflavone content. In 2018, with chitosan treatment, total isoflavone concentration ranged from 551.15 to 7584.07 ㎍ g^-1, with an average of 2972.64 ㎍ g^-1 across cultivars. In 2019, there was no significant difference among treatments in total isoflavone content. Regarding individual isoflavone concentrations, the malonyl-glucoside groups accounted for over 85% of the total isoflavone content, which is indicated that these groups play an important role with regard to isoflavone components in soybean seeds. The individual proportions in the total concentrations of isoflavones varied according to germination period and seed tissues. Glucosides and malonyl-glucosides showed differences in concentrations among seed tissues, aglycones were further accumulated as germination period was progressed. This study suggests that biotic substances have an impact on seed isoflavone content during germination. However, cultivars with consistently high or low isoflavone concentrations across biotic substance treatments were identified desspite differences in germination period and seed tissues, demonstrating that the genetic factor plays the most important role in isoflavone accumulation.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.724-728
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• 1995

Chemical compositions of dried Auricularia polytricha mushroom were analyzed when the dried mushroom were soaked in distilled water at different soaking condition. Physicochemical properties of soaked mushroom were investigated. Compositions of chemical components were 12.6% crude protein, 2.1% crude fat, 6.7% crude fiber and 6.2% ash. The contents of Ca, K, Mg were higher than those of other minerals in the sample, but Mn and Ni were of little quantities. The major amino acids of the sample were found to be aspartic and glutamic acid. The increase in the soaking time and temperature increased the ratio of water uptake, amount of water soluble solid, browning and pH value in the soak water. Ribonucleotide contents of the sample after soaking decreased depending on soaking time and temperature.

• Journal of Wetlands Research
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• v.9 no.3
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• pp.43-49
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• 2007

A ditch is a facility for managing washed-off runoff from parking lot area. Washed-off runoff inflows into ditches where it is retained for a short period of time. At this point, it is assumed that a ditch is a preliminary unit for runoff treatment. This research carries out the distribution of particle size and chemical compound for sediment in parking lot ditch. This work is important to understand the amount of generated sediment from this area to be able to determine different particle size ranges for treatment. Metal concentrations for sediment according to particle size are analyzed. From the distribution of particle size, the weight ratio with the range of $425-850{\mu}m$ is the highest. Considering its weight ratio, the metal concentration of coarser particles is high, otherwise metal concentration increases as particle size decreases. Metal load of the range is higher and the ratio of total metal load in the case of Cu, Pb, Zn is nearly 30%. Moreover metal concentration associated with particle size depends on particle ratio. To manage non-point source pollution for parking lot area, these results can be used with this ditch unit.

• Korean Journal of Food Science and Technology
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• v.39 no.1
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• pp.7-13
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• 2007

The changes in phenolic compounds and pectin content were investigated during the growth of 3 cultivars (Hosui, Niitaka and Chuwhangbae) of Asian pear (Pyrus pyrifolria) fruits. The amounts of total phenolic compounds in peel, flesh and core was 20.61-22.98mg/g, 0.87-1.23mg/g and 6.39-37.96mg/g during early growth, respectively, and decreased with pear growth. Arbutin, chlorogenic acid and epicatechin were detected in each part of all three cultivars during early growth; of these, arbutin content was the highest. Caffeic acid, catechin and 4-hydroxymethyl benzoic acid were detected in the peel and core during the ripening process. The total pectin content in the flesh of Hosui, Niitaka, and Chuwhangbae cultivars decreased from 5.93mg/g, 5.99mg/g and 5.40mg/g to 1.07mg/g, 1.60mg/g and 1.63mg/g, respectively. Of the soluble pectins, the hydrochloric acid-soluble pectin content was the highest, 3.21-3.45mg/g, and decreased during growth.

• Korean journal of food and cookery science
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• v.4 no.1
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• pp.33-40
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• 1988

This study was performed to analyze flavor components of foods, that is, total free amino acids, free glutamic acid(constituent of MSG) and nucleotide relating substances. Twenty-five foods popular to Korean were selected and prepared according to recipes of several cooking books. The results were as follows; In contents of total free amino acids, free glutamic acid and total nucleotide relating substances, similar Patterns were shown. The foods which their major food stuffs were meat, fish and marine products and which a large amount of soy sauce were added to, tended to show high contents. of those On the other hand, although major foodstuffs had relatively high contents of those, foods added other many sub-foodstuffs had shown intermediate contents of those. Soups and watery noodles had low contents of those because of their large water amount. Especially, foods made of vegetables without addition of soy sauce showed low content of IMP. In foods various ratios of free glutamic acid to IMP were calculated. Thus, the proper usage of the chemical seasoning containing nucleotide at various contents should be considered for efficient flavor enhancing effect.

• The Korean Journal of Malacology
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• v.14 no.2
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• pp.103-111
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• 1998

참굴에 다환성방향족탄화수소(PAHs)의 축적성과 이 물질들이 미치는 독성을 평가하기 위해 해양환경에서 빈번히 검출되는 PAHs 중의 하나인 fluoranthene을 사용한 모델연구를 수행하였다. Fluoranthene을 0.01-1ppm의 농도로 2주간 참굴에 노출시켰을 때 참굴 조직내의 fluoranthene의 농도는 노출기간 및 노출농도에 비례하여 최고 40-70배까지 증가하였다. 소화맹낭과 폐각근의 지질 과산화물가는 노출기간 및 노출농도에 관련하여 현저히 증가하였으며 수용성단백질의 함량은 노출기간이 길어짐에 따라 서서히 감소하였다. 그러나 glycogen 함량, nucleoside/nucleotide, DNA 및 RNA 함량은 변화하지 않았다. 이 결과로 fluoranthene은 굴의 조직내로 원활하게 축적함을 확인하였다. 또한 과산화지질의 함량은 fluoranthene에의 오염에 대해 신속히 반응하는 지표의 하나로 추정되며 수용성단백질의 감소도 비록 시간적으로 다소 둔감하기는 하나 또 다른 지표가 될 수 있을 것으로 사료된다.

• The Journal of Engineering Geology
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• v.27 no.1
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• pp.91-101
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• 2017

Fault materials has various properties depending on their areas, rock types, and components because they are formed by heterogeneous and complicated mechanisms. In this study, to understand the physical and mechanical properties of fault materials, 109 fault materials distributed in South Korea were collected to conduct various laboratory tests with them and analyze their physical and mechanical properties (unit weight, specific gravity, porosity, gravel content, silt/clay content, clay mineral content, friction angle, and cohesion) according to areas, rock types, and components. As for the physical and mechanical properties by rock type, gneiss shows the highest medians in the unit weight ($17.1kN/m^3$) and specific gravity (2.73), granite does so in the porosity (45.5%), schist does so in the gravel content (20.0 wt.%) and cohesion (38.1 kPa), and phyllite does so in the silt/clay content (54.4 wt.%), clay mineral content (30.1 wt.%), and friction angle ($38.2^{\circ}$). With regard to the physical and mechanical properties by component, fault gouge was shown to have lower values than cataclasite and damage zones in all factors other than porosity and silt/clay contents.