• Journal of Conservation Science
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• v.8 no.1 s.11
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• pp.51-57
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• 1999

Although the mummies of Lee, Myeong-Jung and his wife whose family name is Moon, were buried in similar sites in 1560's, the degree of decay of the dead bodies and antiquities between two people were quite different. This study was focused on the cause of those differences in the view of engineering concept. Granular soil around the study site shows good drainage and such characteristic could be a factor of excellent conservation of dead body. From the physical characteristics of the material containing lime that is considered to be a barrier from water and air, it was observed that the material around dead body of the wife was more compact and denser than that of the husband. This may suggest that the former is better than the latter in keeping away from the water and air. To understand those differences of physical characteristics between two materials containing lime, minerals had to be identified from the two materials. It was revealed that material containing lime around dead body of the wife contains gypsum and more calcite, which could be the reason for better barrier Preventing from water and air than that around the husband.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.6
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• pp.626-633
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• 2006

Bucheon city has been rapidly urbanized and steadily enlarged. Also, the city depends on groundwater as an alternative water resource. The objective of this study is to characterize the hydrogeology in this city including the recharge of groundwater and hydraulic property of an aquifer in order to investigate the chemical characteristics and contamination of groundwater in the Bucheon area. Eleven groundwater wells in the Bucheon area were selected for applying certain hydraulic tests, such as pumping and recovery tests. Theis method and Theis recovery method were used to obtain hydraulic parameters, such as hydraulic conductivity, transmissivity by applying recovery tests. The playground of school and uncovered areas layed a major function of recharging areas. The groundwater well in these areas showed high recharge, transmissivity, and hydraulic conductivity. In a downtown area, groundwaier wells showed low pumping capacity and hydraulic parameters. Groundwater samples were collected from 48 different locations in the Bucheon area and that showed very various chemical composition in groundwater Their electrical conductivity showed various ranges from 70.4 to $1,287{\mu}S/cm$. The composition more significantly affected the groundwater due to the land use and urbanization than that of the aquifer rock type.

• Journal of Nutrition and Health
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• v.14 no.2
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• pp.87-96
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• 1981

This report was the result of Food and Nutrition Intake Survey of 210 adults of 43 rural households in 7 villages located on Kyung Nam, Korea. It was intended to provide baseline information on the nutrintional status and inequality, the change of food consumption pattern of different rural socioeconomic classes. The survey results were as follows; 1. All the nutrient intakes(except Ca) were above RDA in landlord classes, but those were extremely poor in tenancy and rural laborer classes. Ca was the most deficient nutrient in all classes. 'Vitamin A' was deficient in most of the classes. 2. In per capita food consumption expenditure, the highest was in landlord class, next capitalist farmer and middle class farmer, the lowest were rural laborer and tenancy. There were highest consumption of vegetables and fish in landlord class, and milks and oils in capitalist farmer. The consumption of rice fruits, meats, eggs, and seasoning were relatively proportionated to the income. 3. In the change of food consumption, the most increased items were beverages and meats in capitalist farmer, fish and fruits in landlord, rice in the other classes. 4. In the correlation with food consumption, education level showed the highest correlation with meats, oils, and in contrast, land sire showed the highest correlation with cereals. Engel's coefficient was positively correlated to cereals, but negatively correlated to fish and meats.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.1
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• pp.25-36
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• 2008

When constructing subsea underground structures, the influence of high water and seepage pressure acting on the structures can not be neglected. Thus hydro-mechanical coupled analysis should be performed to estimate the behavior of the structures precisely In practice, relaxed rock load is generally used for the design of tunnel concrete lining. A method based on the distribution of local safety factor around a tunnel was proposed for the estimation of a height of relaxed rock mass ($H_{relaxed}$). In this study, the validation of the suggested method is investigated in the framework of hydro-mechanical coupled analyses. It was suggested that inducing inflow by pumping through a drainage well gave more reliable results than inducing inflow with shotcrete hydraulic characteristics in case of rock condition of Class III. In this study, therefore, inducing inflow by pumping through a drainage well are adopted in estimating $H_{relaxed}$ due to a tunnel excavation with the rock condition of Class I, III, and V. Also the estimated $H_{relaxed}$ results are compared with those of the existing suggested methods. As the result of this study, it is confirmed that estimating $H_{relaxed}$ based on the distribution of local safety factor around a tunnel can be effectively used even for the case of hydro-mechanical coupled analysis. It is also found that inducing inflow pumping through a drainage well gives more precise and consistent Hrelaxed of a subsea structure.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.81-81
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• 2002

$\beta$-Mercaptoethanol($\beta$-ME)은 일반적으로 황화합물(thiol compounds)의 일종으로, 배양액 중에서 이황화결합(disulfide bonds)을 분해하여 일정한 물질의 산화.환원반응에 관여하며, 특히 cysteine이 cystine으로 산화되는 것을 차단함으로서 cysteine의 이용능력을 증대시키고, GSH의 합성을 촉진 및 증대시키는 것으로 알려져 있고, 각종 활성산소로부터 세포를 보호하는 역할을 수행하는 것으로 보고되었다. 특히, 돼지수정란의 체외배양체계에 유의적인 영향을 미치는 것으로 보고되었다(Abebydeera 등, Theriogenol., 50:747-756, 1998). 따라서 본 실험에서는 돼지난포란의 체외성숙시 $\beta$-ME의 첨가배양이 체외수정과 배발달에 미치는 영향에 관하여 조사하였다. 돼지난포란을 10% PFF, 0.1mg/ml cysteine, 10IU/m1 PMSG, 10IU/m1 hCG 및 10ng/m1 EGF가 첨가된 NCSU23 배양액에 $\beta$-ME를 각각 0, 25, 50 및 100uM을 처리하여 22시간 동안 배양을 실시하고, 성선자극호르몬이 배제된 배양액에서 추가로 22시간을 배양하여 체외성숙을 유도하였다. 체외성숙이 유기된 난자는 난구세포를 제거하고, 2.5mM caffeine과 0.1% BSA가 첨가된 mTBM배양액에 정자를 1.25 $\times$ $10^{5}$cells/ml의 농도로 5-6시간 동안 공동배양을 실시하여 체외수정을 유도하였다. 체외수정후 일부의 수정란은 12시간에 난자 급속 염색방법으로 염색하여 다정자침입률 및 자.웅전핵형성률 등을 확인하였다. 그리고 나머지1-세포기의 수정란은 0.4mg/ml BSA가 함유된 NCSU23 배양액에 30 embryos/50ul 소적으로하여 38.8$^{\circ}C$, 5% $CO_2$의 탄산가스 배양기에서 각각 7일간 배양을 실시하였다. 조사된 결과는 SAS/STAT를 이용하여 통계분석을 실시하였다. 체외수정 12시간 후에 난자 급속 염색법으로 염색을 실시한 결과, 모든 처리구에서 핵성숙률(76.4~95.2%), 정자침투율(51.1~66.9%), 웅성전핵형성률(95.2~100%), 다정자침입률(18.2~25.6%) 및 평균침입정자수(1.2~l.4개)에서 유의적인 차이가 인정되지 않았다. 체외배양 48시간 난할률을 조사한 결과, 처리구별 차이(53.9~67.9%)는 인정되지 않았으나, 배양 7일째 배반포형성률은 각각 14.5, 25.4, 17.3 및 12.4%로서 25uM의 $\beta$-ME처리구가 유의적(P<0.05)으로 높은 배발달률을 나타내었고, 총세포수에 있어서는 대조구와 처리구간 유의적인 차이가 인정되지 않았다. 따라서 돼지 난포란을 성숙배양할 때, 25uM $\beta$-ME를 첨가배양하는 것이 양질의 돼지체외수정란을 생산하는 하나의 방법으로 조사되었다.다.

• Journal of Korea Water Resources Association
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• v.39 no.10 s.171
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• pp.881-890
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• 2006

Hydrological characteristics and urbanization effects in the Gap river catchment were investigated employing the SWAT model. The hydrological characteristics analysis showed that total runoff in the whole catchment from 2001 to 2004 consists of 44% of groundwater flow, 6% of lateral flow and 50% of surface flow under year 2000 landuse conditions. The analysis of urbanization effect using different landuse maps for year 1975 and 2000 indicated that although 5% increase in urbanized areas did not significantly impact on the total runoff in the whole catchment, a sub-basin where urbanized area increased by 32% over the past 30 years showed $68{\sim}73%$ decrease in groundwater flow and $22{\sim}66%$ increase in surface flow. It was found that urbanization decreased overall soil moisture and percolation rate except for some increase in soil moisture during dry season. Urbanization effect was found more sensitive during a dry year which has less rainfall and higher evapotranspiration than during a wet year. Therefore, from the results of this study we could infer increased flood damage during wet season and dried stream during dry season due to urbanization. To conclude, the results of this study can provide fundamental information to the eco-friendly restoration project for the three major rivers (Gap-cheon, Yudeung-cheon and Daejeon-cheon) in Daejeon Metropolitan City.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.5
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• pp.175-181
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• 2005

Ingots of rutile single crystals were grown by the skull melting method, and their characteristics were compared in terms of melt-dwelling time for each melt. The method is based on direct inductive heating of an electrically conducted melt by an alternating RF field, and the heating is performed by absorption of RF energy. $TiO_2$ is an insulator at room temperature but its electric conductivity increases elevated temperature. Therefore, titanium metal ring(outside diameter : 6cm, inside diameter : 4cm, thickness 0.2cm) was embedded into $TiO_2$, powder (anatase phase, CERAC, 3N) for initial RF induction heating. Important factors of the skull melting method are electric resistivity of materials at their melting point, working frequency of RF generator and cold crucible size. In this study, electric resitivity of $TiO_2$, $(10^{-2}\~10^{-1}\;{\Omega}{\cdot}m)$ at its melting point was estimated by compairing the electric resitivities of alumina and zirconia. Inner diameter and height of the cold crucible was 11 and 14cm, respectively, which were determined by considering of the Penetration depth $(0.36\~1.13cm)$ and the frequency of RF generator.

• Journal of Life Science
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• v.31 no.1
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• pp.100-108
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• 2021

In the oral cavity, there are hundreds of microbial species that exist as planktonic cells or are incorporated into biofilms. The accumulation and proliferation of pathogenic bacteria in the oral biofilm can lead to caries and periodontitis, which are typical oral diseases. The oral bacteria in the biofilm not only can resist environmental stress inside the oral cavity, but also have a 1,000 times higher resistance to antibiotics than planktonic cells by genes exchange through the interaction between cells in the oral biofilm. Therefore, if the formation of oral biofilm is suppressed or removed, oral diseases caused by bacterial infection can be more effectively prevented or treated. In particular, since oral biofilms have the characteristic of forming a biofilm by gathering several bacteria, quorum sensing, a signaling system between cells, can be a target for controlling the oral biofilm. In addition, a method of inhibiting biofilm formation by using arginine, an alkali-producing substrate of oral bacteria, is used to convert the distribution of oral microorganisms into an environment similar to that of healthy teeth or inhibit the secretion of glucosyltransferase by S. mutans to inhibit the formation of non-soluble glucans. It can be a target to control oral biofilm. This method of inhibiting or removing the oral biofilm formation rather than inducing the death of pathogenic bacteria in the oral cavity will be a new strategy that can selectively prevent or therapeutic avenues for oral diseases including dental caries.

• The Journal of Engineering Geology
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• v.30 no.4
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• pp.603-615
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• 2020

The design factors of artificial recharge are determined by considering the hydrogeological characteristics of the aquifer. The optimal design factors for artificial recharge were derived after performing the injection tests step by step for each injection type (vertical well, ditch and mixed type), which were built in the test site of the study area. It was analyzed that the difference in the injection effect according to the diameter of the injection well was not large, and the 100 mm well was evaluated as appropriate in consideration of the availability and economy of land use. Since the injection effect was well maintained even in the upper rock, the depth of the injection well was proposed for the alluvial layer and the upper rock layer. On the other hand, in four cases of filter media in the ditch, it was analyzed that the penetration efficiency and the hydraulic interference effect indicated excellent injection performance when a filter medium of 10 to 30 mm diameter was filled in the ditch. In addition, the proper spacing of the injection wells was analyzed as 9~12 m considering the interference efficiency. The interference efficiency attenuation coefficient per 1 m of hole spacing was calculated to be 1.75% in this area. In the future study, the artificial recharge design factors obtained in this stage are applied and verified on site construction and operation. Also it is expected to contribute to securing water in areas where there is always a lack of water.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.387-394
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• 2020

In this research, a physical property test of CLSM, which can safely and effectively utilize a great number of industrial byproducts and waste types, was used to review the applicability of GBFS, FNS, and FGB, as well as their field applicabilities as cavity fillers, and the following conclusions have been reached. first, For CLSM utilizing GBFS, FNS, and FGB, it was revealed that a proper mixing of over 30% of GBFS and FNS or within 5% of FGB is effective in improving the fluidity for field application. second, It was revealed that GF15B5 can suppress bleeding at a similar level as the base, whereas GF30B5 can do so at about 0.17% compared to the base. It was also verified that GF15, GF30, and GF45 can suppress bleeding at about 0.2%, 0.26%, and 0.3%, respectively, compared to the base. third, Both GF15B5 and GF30B5 exceeded 0.4MPa in 7day strength tests to satisfy the field application and, also, the rates of increase of their initial strengths were found to be 323% and 233% higher than the base, respectively. Meanwhile, the 7day strength test of GF, which utilizes GBFS and FNS, also reached over 0.2MPa for field application, and it was revealed that GF15, GF30, and GF45 show 160%, 237%, and 185% higher strength increase rates, respectively, compared to the base.