• Journal of the Korean GEO-environmental Society
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• v.17 no.12
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• pp.45-54
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• 2016

In this study, the construction method of new underground continuos impervious wall that the bentonite slurry keeps the stability of excavated trench and the mixture of cement and bentonite plays a role as a constituent of impervious wall in the trench. The merit of homogeneity of the method so called as a cement-bentonite slurry wall enables to accurately make an estimation of hydraulic conductivity of the walls compared with that by other general grouting methods and to verify their waterproof efficiency without difficulty at the design stage. The use of cement-bentonite slurry walls for the containment of groundwater flow has also proven a cost-effective impervious wall technology by employing the simple combination of construction equipments and easy and fast construction procedures. The engineering characteristics of cement-bentonite impervious wall obtained by carrying out the laboratory experiments under various conditions. This study reveals the effect of variation of constituent materials and their mixing methods (Water-Cement-Bentonite) on the engineering characteristics of a composition. Also, this study makes some recommendations on the optimum mixing ratio and mixing sequence for the best quality at the site. That is the most important factors to estimate the construction cost and design of the technique. The comparison is lastly made to evaluate the effect of ordinary Portland and blast furnace slag cement as a bonding material on the behavior of impervious walls.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.193-204
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• 1984

The enzymatic properties of the alkaline AL-protease, which had been prepared from the crude zymolyase of Arthrobzoter luteus, was investigated together with its active amino acid residue. Complete inactivaton of the proteolytic activity of AL-protease by either DFP or PMSF was simultaneously accompanied by the loss of its lytic effect on the lysis of yeast cell wall. In the reaction, AL-protease showed the pattern of inactivation to decrease very slowly, as compared to that of chymotrypsin, and that enzyme and DFP were found to react with a molar ratio of 1 : 1. The preparation of AL-protease exhibited no hydrolytic activity in any substrates of polysaccharases, playing a significant role in the lysis of yeast cell wall. The optimum pH and temperature of AL-protease was pH 10.5 and $65^{\circ}C$, respectively. It also showed stability in the pH range from 5 to 11 and at the temperature below $65^{\circ}C$. Through the identification of the amino acid residue in the active site of the $^{32}P$-diisopropylph-osphorylated(DIP) AL-protease modified specifically with $^{32}P$-labeled DFP, AL-protease was found to be a DFP-sensitive which has a mole of active serine residue involved in its proteolytic activity per mole of the enzyme.

• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.476-488
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• 1997

The purpose of this study was to figure out the suitable field standards for revegetation measures on cut-slopes in consideration of the environmental factors. The field survey was conducted from 1995 to 1996 on highway cut-slopes. The results obtained could be summarized as follows; The major revegetation measures surveyed were 5 major measures as a whole in descending order of seed-spraying measures, block-sod pitching measures, latticed block pitching measures, hydro-seeding measures with seed-fertilizer-soil materials, and several netting measures on highway cut-slopes. According to the analysis of the environmental factors, the plant coverage was affected several major environmental factors which were soil factors(soil hardness, soil texture, soil and rock condition), and site factors(slope gradient, slope length). From a viewpoint of optimum selection, the major 3 factors(soil factors, slope gradient factors, slope length factors) should be considered for selection of revegetation measures on highway cut-slopes.

• Journal of Korea Foresty Energy
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• v.22 no.2
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• pp.1-17
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• 2003

Populus species have been as a model species in tree breeding and we have enormous varieties resulting from the poplar breeding because of their fast growth performance and short rotation age. New varieties developed in Korea are common italian poplar(P euramericana, I-214, I-476), P euramericana“Eco 28”(Italian poplar No.1) and p. deltoides“Lux”(Italian poplar No.2), which were introduced from foreign countries. As hybrid polars, Hyun-Sasi(p. alba ${\times}$ P. glandulosa No.1, No.2, No.3, No4.), P. nigra x P. maximowiczii and P. koreana x P. nigra val. italica, were developed, and P. davidiana was selected as the result of selection breeding The total plantation areas covered with the new varieties are 935,162ha that include 745,773ha of P. euramericana, 184,636ha of P. alba x P. glandulosa, and other new varieties are 4,735ha. The new poplars are contributed to increase farmer's income as well as bare land tree-planting in Korea. The technologies associated with the poplar species were developed, such as the determination of optimum site for new the poplar species, the crossing method between incompatible poplar species, and the vegetative mass propagation. In the future, poplar species will be considered for phytoremediation species at contaminated areas such as landfill sites or with lives stock's waste water as well as wood production, a shade tree like road-side tree and public park tree.

• Journal of the Korea Concrete Institute
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• v.23 no.6
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• pp.773-780
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• 2011

In this study, thermal stress analysis are carried out considering material properties, curing condition, ambient temperature, and casting date of the mass concrete placed in bottom slab and side wall of the in-ground type LNG tank as a super massive structure. Also, based on the numerical results, cracking possibility is predicted and counter measures to prevent the cracking are proposed. For the tasks, two optimum mix proportions were selected. From the results of the thermal stress analysis, the through crack index of 1.2 was satisfied for separately caste concrete lots except for the bottom slab caste in 2 separate sequences. For the double caste bottom slab, it is necessary introduce counter measures such as pre-cooling prior to the site construction. Also, another crack preventive measure is to lower the initial casting temperature by $25^{\circ}C$ or less to satisfy 1.2 through crack index criterion. In the $1^{st}$ and $2^{nd}$ caste bottom slab, the surface crack index was over 1.2. Therefore, the surface cracks can be controlled by implementing the curing conditions proposed in this study. Since the side wall's surface crack index was over 1.0, it is safe to assume that the counter preventive measures can control width and number of cracks.

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.81-89
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• 2010

Since 2004, the government has changedthe cost estimate system to one of an actual cost basis in order to calculate the optimum construction cost by reflecting changes in circumstance on the construction site in a timely manner. Currently, this is being applied to public construction work forover a billion won of actual cost data in estimation by contract unit cost. However, directly reflecting actual cost, which for large-sized construction work was originally an average unit cost, to a small building, entails the application of a low discount rate for the cost of materials, labor, etc. and therefore can frequently give rise to cases in which the actual cost of work performed exceeds the contract sum, which in turn causes problems such as decreased revenues, bad effectson business operation, productivity, etc. Therefore, to apply actual cost to small-sized construction work (less than a billion won), there should be a plan to modify unit cost in a manner that can reflect project scale, etc. in order to resolve the problem of unit cost application of actual cost to small-building construction projects. The unit cost modification model for proper actual construction cost in small-scale construction projects developed by this study will help to increase the relevant productivity and proper gain, preventing the aggravation of business operations. Organizations placing orders are also expected to be able to secure a more realistic construction cost in arranging the budget.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.567-572
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• 2010

5,10-Methenyltetrahydrofolate synthetase from chicken liver was purified through 30-70% ammonium sulfate fractionation, Q Sepharose Fast Flow anion exchange and Source 15Phe hydrophobic interaction chromatography. Specific activities of cell extract, ammonium sulfate, Q Sepharose Fast Flow and Source 15Phe were 0.0085, 0.031, 0.80 and 1.27 U/mg, respectively. Purification fold activities of cell extract, ammonium sulfate, Q Sepharose Fast Flow and Source 15Phe were 1, 3.7, 94.1 and 149.4, respectively. HPLC gel permeation chromatography and SDS-polyacrylamide electrophoresis experiments indicated that the enzyme is a monomeric protein with a molecular weight of 22.8 kDa. Km for 5-methyl THF and Mg-ATP were $7.1\;{\mu}M$ and $63\;{\mu}M$, respectively. Optimum temperature and pH were $30^{\circ}C$ and 6.0, respectively. The data for metal ion specificity and stoichiometry showed that the maximum activity was obtained with a 1:l. ratio of $Mg^{2+}$. The ATP and Km values increased in the order of MgATP, MgCTP, MgUTP and MgGTP, and the maximum activities also decreased in the same order, indicating MgATP as the most efficient substrate. The enzyme was chemically modified only by tetranitrometane and 1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide, indicating that tyrosine and carboxylate are present in the active site.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.125-130
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• 2005

The ecological characteristics of the specialist insect predator, Oligota kashmirica benefica, were investigated for developing artificial rearing method with special interest on the oviposition behavior, the pattern of adult emergence and temperature in storage, and its effect on the density of the citrus red mite, Panonychus citri. Female beetle oviposited eggs mainly, $95\%$ of the eggs, on the bottom of leaves of the yuzu tree, and $91.3\%$ of them were covered with ecdysis skin of the red mites or the feces of themselves. The rate of adult emergence of the beetle rose up to $86.7\%$ when the horticultural media was provided for pupation from $60\%$ when it pupated in upland soil. Most larvae, $88\%$ of them, were found from the surface to the depth of 2 cm in the horticultural media. The optimum temperature for the storage of the adult beetle was found to be $12^{\circ}C$, at this temperature the 96.7, 73.3 and $70.0\%$ of the beetle survived for 10, 20, and 30 days, respectively. The control effect of the citrus red mite was appeared highest by releasing the beetle at the rate of one beetle against 150 mites.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.1
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• pp.11-20
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• 2010

Oyster production is playing an important role in domestic aquaculture, but facing some problems such as exports decrease, a slowdown in domestic demand and marine environmental deterioration. In order to obtain the suitable and sustainable oyster production, suitable sites selection is an important step in oyster aquaculture. This study was conducted to identify the suitable sites for lunging culture of oyster using Geographic Information System(GIS)-based multi-criteria evaluation methods. Most of the parameters were extracted by Inverse Distance Weighted(IDW) methods in GIS and eight parameters were grouped into two basic sub-models for oyster aquaculture, namely oyster growth sub-model(Sea Temperature, Salinity, Hydrodynamics, Chlorophyll-a) and environment sub-model(Bottom DO, TOC, Sediment AVS, Benthic Diversity). Suitability scores were ranked on a scale from 1(leased suitable) and 8(most suitable), and about 80.1% of the total potential area had the highest scores 5 and 6. These areas were shown to have the optimum condition for oyster culture in GeojeHansan Bay. This method to identify suitable sites for oyster culture may be used to develop bivalve culture management system for supporting a decision making.

• Water for future
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• v.14 no.4
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• pp.73-81
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• 1981

More than 650 numbers of water well ranging in depth from 100M to 200M were installed in South Korean Penninsula during the last decade for the purpose of industrial use and municipal water supply. Those data were compiled and synthesized by writer to determine their hydrogeologic occurences in accordance with their geologic and areal characteristics. Rocks yielding the deep seated ground water beared in the geologic primary and secondary porosities are classified into 6 groups according to their geologic, hydrogeologic, and topographic characteristics, that are: volcanic, sedimentary, meta-sediment and/or schist, andesitic, gneissic, and granitic rocks. The order of ground water productivity of the groups is as written above. Even granitic rocks including porphyries, granite, and intermediate and basic plutonic rocks is considered to be the most poorest ground water yielding group among 6, it's average yield form a single well with average drilling depth of 116M is about 225 cubic meters per day if it's drilling site is properly located. Generally speaking, seizable geologic structures such as fractured, sheared, and faulted zone at the flat surface and valley center yield almost 310% more of deep seated bet rock ground water in comparision with minor structures of joints, bedding planes, and so on that are occured at high land. 50 numbers of water well drilled at crystalline rocks were specially checked and measured it's ground water yie 1ds at each drilled depth to determine each interval's productivity while hammer drilling was going on. The results indicate that the specific capacity and yield of each water well at a depth below 70M to 80M was almost neglegible. It means that optimum well depth of crystalline rocks, except the area having seizable geologic structures, shall be not deeper than 80M.