• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.1
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• pp.115-123
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• 1990

The purpose of this study was to examine the uses of coal ash as a type of construction material. The methods of examination were chemical anlysis, soil laboratory test and the soil vibration test. Materials used were coal ash obtained as a by-product from 5 thermal power plants in Yongdong, Yongwol, Sochon(anthracite coal) and in Samchonpo and Honam (bituminous coal). Over 70% of the coal ash consisted of silica and alumina. The fly ash grain size showed a uniform distribution from fine-sand to silt, and that of the bottom ash showed from sand to gravel. The specific gravity and density of the coal ash were low. The long term strength increased gradually due to the self-setting property resulting from pozzolanic activity. The shear strength was higher than that of general soil. Cohesion and optimum moisture content of anthracite coal ash were higher than bituminous coal ash, whereas the maximum dry density was higher in bituminous coal ash. The coal ash dynamic Young's modulous curve range was similar to that of general soil. Of the results from the soil vibration test by car-running, the size relative acceleration level in the ash pond was higher than that of natural ground, but the damping ratio was lower than that of natural ground near the ash pond. The coal ash has more advantageous engineering properties than general soil with particles of the same size. For example, the California Bearing Ratio of the bottom ash at both Yongdong and Yongwol was 77~137%. Therefore we expect that if further study is done, coal ash can be used as a construction material when reclaiming seashore, construction embankments, road construction, making right-weight aggregate, or as a general construction material.

• Economic and Environmental Geology
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• v.53 no.1
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• pp.1-9
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• 2020

Magnesium silicate minerals such as serpentine [Mg₃Si₂O₅(OH)₄] have a high potential for the sequestration of CO₂; thus, their reactivity toward dissolution under CO₂-free and CO₂-containing conditions in acidic solvents is a critical process with respect to their carbonation reactions. To examine the carbonation efficiency and dissolution mechanism of serpentine, hydrothermal treatment was performed to the starting material via a modified direct aqueous carbonation process at 100 and 150℃. The serpentine dissolution experiments were conducted in H₂SO₄ solution with concentration range of 0.3-1 M and at a CO₂ partial pressure of 3 MPa. The initial pH of the solution was adjusted to 13 for the carbonation process. Under CO₂-free and CO₂-containing conditions, the carbonation efficiency increased in proportion to the concentration of H₂SO₄ and the reaction temperature. The leaching rate under CO₂-containing conditions was higher than that under CO₂-free conditions. This suggests that shows the presence of CO₂ affects the carbonation reaction. The leaching and carbonation efficiencies at 150℃ in 1 M H₂SO₄ solution under CO₂-containing conditions were 85 and 84%, respectively. The dissolution rate of Mg was higher than that of Si, such that the Mg : Si ratio of the reacted serpentine decreased from the inner part (approximately 1.5) to the outer part (less than 0.1). The resultant silica-rich layer of the reaction product ultimately changed through the Mg-depleted skeletal phase and the pseudo-serpentine phase to the amorphous silica phase. A passivating silica layer was not observed on the outer surface of the reacted serpentine.

• Journal of the Korean Society of Food Culture
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• v.9 no.4
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• pp.379-394
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• 1994

The purpose of this study was to identify the correlation between the factors influencing on housewives' decision-making processes of organic foods and the relating variables, and the 5 stages of decision-making processes of the EBK model is utilized in this study. The sample was selected from 411 housewives living in Seoul from 1st of September through 20th of September, 1993. Frequency, Percentage, Mean, Factor analysis, One-way ANOVA, Duncan's multiple range test, t-Test, Correlation, Multiple regression analysis and Path analysis were measured. Major results are as follows: 1. Purchasing motivation of the organic foods were in order of the health care, nutritive value and taste care. 2. The major informations source for the knowledge of organic foods were in order of TV/radio, newspaper/magazine, recommendations informations and advice through a family/friends/acquaintances. 3. Evalution criteria in shopping of organic foods, the total degree of consideration over the purchasing factors of organic foods was fairly high level: consumers thought much of the sanitation/freshness, nutritive value and the food safety. In this regard opinion leaders was dominantly mass media. Consumers have a tendency to purchase organic foods in consideration of their children and husband. 4. Major place to purchase organic foods are super markets and department stores. And When shopping organic foods, housewives by all means confirm the check points in their own mind, which were expiry date, manufactured date and packing condition, but unexpectedly manufactured company was out of concern. 5. Housewives usually satisfy with decision after purchasing organic foods, while they were fairly unsatisfied with the price, quality, incomplete description for ingredients and manufactured date. 6. The variables influencing to the sincerity when selecting the most desired organic foods is how be cares about the natural freshness of the foods and the types of residents in order. Another interesting tendency is the richer they are very considerate to decide. It is to say the people who cares more about the natural freshness is the sincerer when making decision and also the class who lives in the apartment house enjoying high income do not easily accept the product quality.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.71-80
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• 2012

Vinca alkaloids produced from Catharanthus roseus are one of the most important natural product drugs in treatments of human cancers. These anticancer drugs are derived from coupling of the two monomeric indole alkaloids, catharanthine and vindoline. In order to investigate vindoline biosynthesis, tabersonine-$CD_3$ 1a is synthesized to use as a deuterium labeled precursor, which is distinguished clearly from the natural counterpart. We show that these deuterium labeled tabersonine 1a are successfully incorporated into the vindoline biosynthetic pathway to yield three deuterated vindoline intermediates. 16-Hydroxytabersonine-$CD_3$ (m/z 356) 2a, 16-Methoxytabersonine-$CD_3$ (m/z 370) 3a, 16-Methoxy-2,3-dihydro-3-hydroxytabersonine-$CD_3$ (m/z 388) 4a are produced from the cell suspension culture measured by UPLC/MS at 5 and 13 days after feeding tabersonine. The conversion rates from 1a to 2a and 2a to 3a are fast, whereas that from 3a to 4a is much slower. This indicates that the rate determining step among the first three vindoline biosynthesis is the last step. As a result of the slow conversion rate from 3a to 4a, the accumulation level of 16-Methoxytabersonine-$CD_3$ 3a is significantly increased up to 13 days. The accumulation ratio among 2a, 3a and 4a is 1, 2 and 0.1 at 5 days. However, the peaks of desacetoxyvindoline-$CD_3$ 5a, deacetylvindoline-$CD_3$ 6a and vindoline-$CD_3$ 7a are not found from the cell extracts even after 13 days of incubation which may indicate no presence of their corresponding enzymes.

• Korean Journal of Heritage: History & Science
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• v.52 no.4
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• pp.78-103
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• 2019

The Conservation Decree of the Chosun Treasures Historic and Natural Monuments (hereinafter referred to as the Conservation Decree), which was enacted during the Japanese colonial period, was preserved in accordance with the provisions of article No. 100 of the constitutional law. However, legislative attempts were made to replace the Conservation Decree during the US military administration and early Korean Government. The first attempt was about the National Treasures Historic and Natural Monuments which were brought in by the Legislative Assembly of South Chosun (1947) during the US military administration. The second was a bill by the government for preservation of historical interests (1950), which was submitted to the National Assembly on March 15, 1950 (the so-called Preservation Act (1950)). These two bills were amended and supplemented on the basis of the existing contents of the Conservation Decree. Afterwards, from 1952 to 1960, the legislation of the Cultural Heritage Protection Act (1959) and the Cultural Heritage Bill (1960) were subsequently introduced and enacted. The government's attempt to enact such a cultural property bill was aimed at the legislature to replace the preservation order system that had been in effect since the Japanese colonial period. However, due to the political situation at the time, these laws did not reach final legislation. In October 1960, the government enacted the Regulations for the Preservation of Cultural Property, which was an administrative edict that was promulgated and enacted in November. This was the first official cultural property decree introduced by the Korean government. With the enactment and promulgation of the Cultural Heritage Protection Act in January 1962, Korea's judicial cultural property legislation was established, based on the Korean government's unremitting efforts and experience in legislation of cultural property. In that context, the Cultural Heritage Protection Act is a historical product. The Cultural Heritage Protection Act, which was enacted in 1962, is known to emulate or transplant Japan's Cultural Heritage Protection Act (1950). It was not fully recognized that it was an extension of the Korean government's legislative process of cultural property during the period of 1945-1960. Therefore, it is important to examine the legislative process of cultural property from 1945 to 1960 to understand the background of enacting the Cultural Heritage Protection Act in 1962 along with the establishment of the Korean Cultural Property Law.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.1
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• pp.103-112
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• 2006

Along with recent improvement of recycling technique, the quality of the recycled concrete aggregate have become very competitive to the natural concrete aggregate. Therefore, a practical use of the recycled concrete aggregate may be possible for structural members. Majority studies about the recycled concrete aggregate was emphasized a limitation of fundamental study concerned with a strength characteristics and durability of the recycled aggregate concrete, there is use for the structural members. Therefore, for the extension of application of recycled concrete aggregate, this investigation verifies the strength characteristics recycled concrete aggregate of the spun-concrete products with various coarse and fine recycled aggregate replacement ratio(coarse recycled aggregate: 0%, 20%, 40%, 60%, 100%; fine recycled aggregate: 0%, 30%, 60%, 100%) and with addition of cellulose fibers(0%, 0.01%, 0.03%, 0.05%, 0.08%). From the test results, The strength of spun concrete used with recycled aggregate [NR specimen], was measured as 72MPa, was found to be very approximately to the strength of spun concrete used with the natural aggregate(NN specimen), was measured as 74MPa, when only fine aggregate was replaced with the recycled. Therefore, the fine recycled concrete aggregate can be successfully used in the spun high strength concrete product. The compressive strength of all specimens used the specialty cellulose fiber were measured as about 70M Pa, however, the increasement of the specialty cellulose fiber content is showed to decrease compressive strength of spun concrete. Therefore, it is anticipated that the specialty cellulose fiber can be applied to the various spun concrete products.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.2
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• pp.145-152
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• 2012

Whenever pediatric dentists choose the preformed stainless steel crowns for restoration of primary molars, we usually prefer the crown forms that most fit to the abutment teeth. Despite some previous reports on significant ethnic difference in the size and shape of tooth crowns in primary dentition, only the imported products have been available to date, which might show some discrepancy with tooth anatomy of Korean. However, a domestic product of preformed stainless steel crown has been marketed recently that is expected to show more accurate fit to the primary tooth of Korean. To investigate the morphological characteristics of primary molars of Korean children, their mesiodistal and buccolingual diameters from the dental casts of 263 children in Pusan and Kyungsangnamdo province were measured by digital calipers. The measured data were compared with those of the three types of preformed stainless steel crowns(3M ESPE Stainless Steel Primary Molar Crown, Kids Crown, Sankin Anatom Primary Crown) by statistical processes with regression analysis. The results were as follows: 1. In every primary molar crown of three brands, the bucco-lingual width to mesio-distal width ratio (MD-BL ratio) showed higher values compared with those of natural teeth. 2. While the products of 3M ESPE and Shinhung showed similar features, those of Sankin showed some difference from both, and these difference was more marked in mandibular primary molars. 3. The nearer is the mesio-distal width of the crown to the average, the better was the adaptation of the preformed crown, and the reverse was true. 4. The teeth which revealed more discrepancy between preformed crown and natural tooth were upper and lower first primary molars.

• The Korean Journal of Mycology
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• v.31 no.3
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• pp.175-180
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• 2003

To develop the health/functional food materials, we investigated the cultural condition of mycelial growth on the solid state fermentation using the brown rise, Acanthopanax sp. and Artemisia sp., and also evaluated inhibitory activity of angiotensin converting enzyme (ACE) of hot water extracts from cultured media of Pleurotus eryngii. As the amount of Acanthopanax nnd Artemisia In the cultural media increased, the mycelial growth rate decreased. Especially, addition of Aeantopanax showed marked effect than Artemisia. Moisture contents in three kinds of cultured media were in the range of $10.9{\sim}12.0%$. Crude protein fat and crude fiber content were the highest value in cultured brown rice medium, whereas the mineral contents (Ca, K and P) were higher in the Acanthopanax supplemented (5%) medium than the other media, The extraction yield of the Artemisia supplemented (5%) medium was the highest value of 4.80%, and the pH of hot water extract from cultured brown rice medium showed the lowest value of 6.1. Lightness (L) values in three kinds of extracts from cultured media were in the range of $85.8{\sim}87.1$. Redness (a) value was the highest In the brown rice and Acanthopanax supplemented media, however cultured Artemisia supplemented medium showed the highest value in yellowness (b). In comparison of sugar components analyzed by the thin layer chromatography with three kinds of samples, two spots were detected to be glucose and maltose, respectively. The ACE inhibitory activity of hot water extract from the cultured Acanthopanax supplemented medium showed the highest value at the concentration of $0.2{\sim}1.0\;mg/ml$. These results suggest that the Pleurotus eryngii grew in natural media using brown rice and Acanthopanax can be supplemented to the brown rice medium to enhance its ACE inhibitory activity as health/functional food materials.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.461-471
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• 2016

This study was conducted to establish an in vitro propagation system for sea-milkwort (Glaux maritima L.), which is an endangered coastal plant species with high horticultural value. Two phenotypes, 'Red type (RT)' and 'Pistachio type (PT)' based on the colors of stem and flower, were obtained from a personal horticulturist in 2009 and used for this study as plant materials. The stock plants showed typical morphologies in flower, capsule, and seed appearances as previously reported. Low temperature treatment at $4^{\circ}C$ for four or more weeks after in vitro sowing maximized seed germination percentage, indicating that imbibition of seed and subsequent low temperature treatment are crucial for its germination. The in vitro seedlings had phenotypic variation, falling into 'RT' and 'PT' classes like the stock plants. Although slight differences depending on genotype and medium were recognized, the fourth or fifth nodes detached from the in vitro seedlings revealed the best multiplication efficacy when estimated on the basis of total number of nodes of newly developed axillary shoots. In addition, the nodes from 'RT' and 'PT' regenerated the most shoots on medium supplemented with $0.5mg{\cdot}L^{-1}$ BA alone and $0.5mg{\cdot}L^{-1}$ BA plus $0.5mg{\cdot}L^{-1}$ IAA, respectively. The node culture-derived plantlets were well acclimatized in a culture room ex vitro and completed the pseudo-annual life cycle coincident with that in the natural salt march habitat with the current cultivation method of applying fresh water-irrigation under an inland environment. This work represents the first report of in vitro propagation of sea-milkwort. Thus, our study will contribute to exo-habitat conservation and natural habitat restoration of this endangered species in addition to development of a horticultural product.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.977-983
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• 2002

This study was performed to establish the precise and rapid method to distinguish croakers through the pigment analysis of colored imported white croakers for adultration. We surveyed the coloring behaviors, extraction test by water and organic solvent and using pigments such as targeting, curcumine, and azo dye products. The pigment of yellow croaker is not stained on wet cloth or tissue which is rubbed on epidermis of yellow croaker and was not eluted in water extraction test, while adulterated pigments were easily extracted by water and acetone, but edible diluted yellow, Yellow No. 4 and Yellow No. 5 were not extracted. Reactive pigment was detected easily by extraction with water and dispersed pigment was also detected by extraction test. As a result of discoloring characteristics of carotene having similar structure to yellow croaker and azo dye by oxidation and reduction, azo dyes were not discolored by oxidation with sodium percarbonate or peracetic acid but that were discolored by oxidation with Fenton reagent after 1hr and by hypochlorite promptly. On the other hand, carotenes were not discolored by sodium precarbonate and Fenton reagent but discolored by sodium hypochlorite after 2 hr and by peracetic acid promptly. Azo dyes were discolored by reduction with sodium hydrosulfite and sodium carbonate but carotenes were not discolored by these reagents. This discoloring test was applicable to detect adulterated pigments and other marine product.