• Proceedings of the KSEEG Conference
• /
• 1999.04a
• /
• pp.257-259
• /
• 1999

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.12
• /
• pp.1075-1080
• /
• 2009

The partial lipid degradation with the saturation of double-bond at the acidogenesis stage is known to help subsequent methanogenesis during anaerobic digestion. Acidogenic reactions in an anaerobic sequencing batch reactor (ASBR) and a continuously stirred tank reactor (CSTR) were carried out to compare their performances. A mixture of two unsaturated (oleate and linoleate) and two saturated (palmitate and stearate) long-chain fatty acids (LCFAs) was used as a model substrate. Biomass retention in the ASBR contributed to the enhanced performance at hydraulic retention time (HRT) below 15 hr. Biomass retention in the ASBR contributed to the enhanced performance compared to CSTR even at shorter HRT. ASBR would be a proper reactor configuration for the acidogenesis of lipid-containing wastewater.

• The Journal of Engineering Geology
• /
• v.18 no.1
• /
• pp.55-68
• /
• 2008

At present underground structures such as road tunnels, railway tunnels, underground petroleum storages and radioactive waste storages are being constructed in numerous places in Korea. For the construction of underground structrues, it should be accounted for natural factors (geology, hydrogeology, soil, vegetation, topography and drainage patterns) and human-social factors (land use, urbanization, population, culture and transportation). Especially, hydrogeology should be regarded as an important factor for evaluating the safety of underground structures and their impact to groundwater system around the structures. This study aimed to recognize hydrogeological characteristics of shallow formations in the area from Dongrae crossway to Seo-Dong where 45 boreholes were drilled for the construction of Line-3 subway in Busan Megacity. Slug tests for unsaturated and saturated zones were conducted on 30 boreholes in the study area. From the result of the slug tests, it was identified that average zonal hydraulic conductivity in the unsaturated zone was higher than that in the saturated zone. Besides, the slug test result in the saturated zones may reflect hydraulic properties of the upper most part of the saturated zones.

• Economic and Environmental Geology
• /
• v.35 no.5
• /
• pp.479-490
• /
• 2002

The aim of this study is to evaluate the contributions of each hydrogeological factors to groundwater recharge ratios in order to determine areal estimates of recharges in entire inland area of South Korea. For this purpose, various statistical analyses and overlay techniques of GIS were conducted fur entire area and 4 river basins of South Korea. As a result, the spatial distribution of recharge, South Korea were visualized.

• Proceedings of the KSEEG Conference
• /
• 2007.04a
• /
• pp.572-575
• /
• 2007

• The Journal of Engineering Geology
• /
• v.14 no.2
• /
• pp.179-187
• /
• 2004

This study conducted a laboratory work to determine the change of dielectric constant of saturated soil porous media, which is injecting EML to use Frequency Domain Reflectometry(FDR) system and length 7cm-length measurement sensor. It is purpose of study that estimate a movement path through pore of soil for an ethanol mixing liquid(EML) which have the same specific gravity of water at $20{\;}^{\circ}C$, and determine to a dielectric measuring range for the measurement sensor. As an outflow point of saturated soil column upper part recedes from an EML inject point in EML diffusion test, the diffusion extent of EML through pore of saturated soil was expanded. And results of ail EML flow experiment were measured the change of dielectric constant at all measurement sensors which are placed to constant interval at the same travel time for saturated soil column. Therefore, the displace process of water that exist in pore of saturated soil by EML injection is enough available and confirm together mobility through pores.

• The Journal of Engineering Geology
• /
• v.32 no.2
• /
• pp.209-219
• /
• 2022

To experimentally investigate the variation of soil characteristics in slope during rainfall and the shape of slope failure, the model test was performed using soil box and artificial rainfall simulator. The model test of slope formed by the homogenous sand was performed, and the saturation pattern in the model slope due to rainfall infiltration was observed. The slope model with the inclination of 35° was set up on the slope of 30°, and the rainfall intensity of 50 mm/hr was applied in the test. The soil depth of 35 cm was selected by considering the size of soil box, and the TDR (time domain reflectometry) sensors were installed at various depths to investigate the change of soil characteristics with time. As the result of model test, the slope model during rainfall was saturated from the soil surface to the subsurface, and from the toe part to the crest part due to rainfall infiltration. That is, the toe part of slope was firstly saturated by rainfall infiltration, and then due to continuous rainfall the saturation range was enlarged from the toe part to the crest part in the slope model. The failure of slope model was started at the toe part of slope and then enlarged to the crest part, which is called as the retrogressive failure. At the end of slope failure, the collapsed area increased rapidly. Also, the mode of slope failure was rotational. Meanwhile, the slope failure was occurred when the matric suction in the slope was reached to the air entry value (AEV) estimated in soil-water characteristic curve (SWCC).

• Monthly Duck's Village
• /
• s.46
• /
• pp.78-79
• /
• 2007

오늘날 질병은 과거의 질환이나 섭생부주의로 오는 것이 아니라 호흡과 음식물의 섭취를 통해 체내에 유입돼 축척되는 온갖 독성물질과 중금속, 유해물질이 면역체계를 약화시켜 발생한다는 것이 지금의 의학계 소견이다. 오리의 지질을 구성하는 지방산 조성이 다른 육류와는 크게 다르다. 포화 지방산이 20% 정도인데 불포화 지방산이 70% 이상이다. p/S비율(불포화 지방산 함량을 포화 지방산 함량으로 나눈 값)은 3.4이며 포화 지방산인 팔미트산의 함량이 다른 육류에 비해 적다. 또한 콜레스테롤 함량도 적은 편이다.

• The Journal of Engineering Geology
• /
• v.31 no.2
• /
• pp.165-178
• /
• 2021

The influence of Soil-Water Characteristic Curve (SWCC) fitting parameters for an unsaturated natural slope was evaluated through seepage and slope stability analysis as a function of rainfall. Soil samples were collected from the study area in Jirisan National Park and the physical and mechanical characteristics of unsaturated soil layers were measured in laboratory tests. The saturation depth was calculated via seepage analysis by changing fitting parameters α, the parameter related to the Air Entry Value (AEV) and n, the parameter related to the slope of the SWCC in the range of natural conditions. Slope stability analysis using the limit equilibrium method considered the calculated depth of saturation. Results from seepage analysis for various rainfall conditions indicate the saturation depth in the soil layer suddenly increased as the fitting parameter α decreased; the saturation time for the entire soil layer also decreased. Slope stability analysis considering the calculated depth of saturation shows that the slope safety factor rapidly decreased as the fitting parameter α decreased, whereas the variation in slope safety factor was very small when n increased. Hence, fitting parameter α has a large effect on saturation depth during rainfall and therefore on slope stability, whereas slope stability is relatively unaffected by the fitting parameter n.

• Journal of Nutrition and Health
• /
• v.21 no.5
• /
• pp.295-304
• /
• 1988

To study effect of dietary polyunsaturated fatty acid and $\omega$-tocopherol content on lipid peroxidation in rat liver, rats were fed for 3, 6 and 9 weeks with normal tocopherol diet added 40mg of DL-$\alpha$-tocopherol/kg of diet (PF group), high tocopherol eit 200mg of DL-$\alpha$-tocopherol/kg of diet(PFE group), low tocopherol diet without addition of DL-$\alpha$-tocopherol to diet(PFO group), and control diet added 40mg of DL-$\alpha$-tocopherol/kg of diet(control group). Each diet group supplied 45% of total calorie from corn oil except control group which supplied 12% of total calorie from corn oil. After each feeding period, lipid peroxide and tocopherol contents were measured in the liver as well as activities of glutathione peroxidase and superoxide dismutase. PF group had almost the same contents of liver peroxide, tocopherol contents and activities of glutathione peroxidease and superoxide dimutase as control group, while PFE group had higher tocopherol content and glutathione peroxidase activity and lower lipid peroxide contents and superoxide dismutase activity than control group. On the other hand, changes in the values of PFO group were opposite to those of PFE group. Differences in the values among groups were more pronounced as feeding period became longer.