• Applied Chemistry for Engineering
• /
• v.8 no.4
• /
• pp.624-630
• /
• 1997

Zeolite A helps an increase of detergency performance according to showing the ion exchange effect for polyvalant ions and it's detergency performance could be calculated quantitatively by using the disperse stabilization theory because it is water-insoluble material and is as colloid particles in aqueous solution. In this study, zeta potential of carbon black, cellulose, and Zeolite A were measured in each inorganic salt solutions and applied to the theory of Heterocoagulation in order to evaluate the detergency performance of Zeolite A about the particulate soil at the view point of interaction potential energy. Zeolite A was shown help an increase of detergency performance according to the increasing of the steric repulsion between Zeolite A and cellulose in $Na2CO_3$ solution and the decrease of re-deposition of carbon black on the fabric by rapid coagulation with carbon black in $Na_2SO_4$ solution.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.29 no.5
• /
• pp.377-388
• /
• 2016

This study is aimed to evaluate the embedment effect of foundation as compared to the surface foundation on the response of a base-isolated nuclear power plant structure. For this purpose, the boundary reaction method (BRM), which is a two-step frequency domain and time domain technique, is used for the nonlinear SSI analysis considering nonlinear behavior of base isolators. The numerical model of the BRM is verified by comparing the numerical results obtained by the BRM and the conventional frequency-domain SSI analysis for an equivalent linear SSI system. Finally, the displacement response of the base isolation and the horizontal response of the structure obtained by the nonlinear SSI analysis using the moat foundation model are compared with those using the surface foundation model. The comparison showed that the displacement response of the base isolation can be reduced by considering the embedment effect of foundation.

• Korean Journal of Environment and Ecology
• /
• v.15 no.2
• /
• pp.139-152
• /
• 2001

충남 서부 활석광산 주변의 수계에 대한 원소 함량특성에 대해 알아보고자 대흥 및 광천광산에 대해 수질 및 하상 퇴적물 시료와 함께 광산 주변 토양 및 모암 시료를 채취, 비교하였다. 대흥지역 퇴적물은 대부분 원소에서 SP가 GN에 비해 높았는데 이는 퇴적물 내 유색 및 무색광물 함량 차이로 판단된다. 절대 함량 비교에서 광물 결정구조 내 쉽게 Mg와 치환하는 원소는 낮은비율을, Fe와 치환하는 원소는 높은 비율을 보였는데 이는 퇴적물 내 주 구성광물내 원소 치환특성을 반영하기 때문으로 판단된다. 절대 함량의 감소 순서와 타원소들과 높은 상관관계(>0.85)의 빈도를 보이는 원소들 사이의 차이는 퇴적물 화학조성에 이차광물과 비정질 광물등의 조성도 반영되었음을 암시한다. 대흥지역 지표수는 대부분 원소에서 MSP가 SP와 GN의 중간값을, MSG는 LGN과 MSP의 중간값을 조여 수계의 혼합특성을반영하는 것으로 판단된다. 절대 함량관계에서는 SP는 GW1과 유사했고, GN은 LGN과 유사했으며, 절대함량은(Mg, Fe), (As, Sc), (Mo, V, Se) 순서로 낮아졌다. 광천지역은 갱내수가 천부 지하수에 비해 대부분 원소에서 높은 함량을 보였는데, 이는 갱내수가 더욱더 많은 물-암석반응을 거친 때문으로 판단된다. 절대 함량은 Mg, Br, Fe, (Sc, Cr), (An, Ni, V)순서로 감소하였다. 갱냉수의 지역간 원소 함량 차이는 사문암화가 우세한 광천지역과 활석화가 우세한 대흥지역 모암들 사이의물-암석 상화반응의 차이를 보여주는 것으로 판단된다 두 지역의 상부 토양 및 모암 조성에서 SP가 GN에 비해 높은 Mg 비, Ni, Cr, Co 등 함량을 보였는데, 이는 사문암 지역 내 Mg, Ni, Cr 등이 풍부한 광물들 탓으로 판단된다. 퇴적물과 수질 사이에서는 함량 경향을 뚜렷하지 않았고 원소에 따라 서로 다른 힘량 차이를 보였는데, 이는 퇴적물 원소 함량이 수계 조성을 반영하는 것이 아님을 나타낸다. 상부-토양-암석-수계의 조성관계에서 대흥지역 지표수 중 SP 조성이, 광천지역은 갱냉수가 지하수의 조성에 가까웠다.

• Journal of the Korean Geotechnical Society
• /
• v.19 no.4
• /
• pp.223-233
• /
• 2003

Sand compaction pile (SCP) is one of the ground improvement techniques which are being used for not only accelerating consolidation but also increasing bearing capacity of loose sands or soft clay grounds. In this study, laboratory model tests and 3-D finite element analyses were performed to investigate the interaction between sand compaction piles and surrounding soft soils. Based on the results obtained, as the area replacement ratio increases, the stress concentration ratio increases at the pile point, the settlement decreases, and the relative displacement between column and soil also decreases. It is also found that numerical study is illustrated by good comparison with model test results, and the numerical analysis revealed slip effects which could not be specifically identified in the model tests.

• Journal of the Korean GEO-environmental Society
• /
• v.10 no.7
• /
• pp.135-141
• /
• 2009

For more reliable estimation of soil-structure interaction and seismic source and attenuation properties, site amplification function should be considered. This study use the Nakamura's method (1989) for estimating site amplification though various methods for the same purpose have been proposed. This method was originally applied to the surface waves of background noise and therefore there are some limitation for applications to general wave energy. However, recently this method has been extended and applied to the S wave energy successfully. This study applied the method to the coda wave energy which is equivalent to the backscattered S wave energy. We used more than 60 observed ground motions from 5 earthquakes which occurred recently, with magnitude range from 3.6 to 5.1 Each station showed characteristic site amplification property in low-, high- and resonance frequency ranges. In the case of comparing these results to those from S wave energy, lots of information to the site classification work can be gained. Moreover, removal of site amplification can give us more reliable seismic source parameters.

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 2004.11a
• /
• pp.139-143
• /
• 2004

To evaluate the biological and physiological response of Picea koraiensis Nakai to elevated $CO_2$ and nitrogen.3-year old seedlings were planted in an ambient and 700 ppm $CO_2$ at low (2mM $NH_4NO_3$) or high nitrogen (16mM $NH_4NO_3$) supplying treatments for 3 months. Photosynthetic parameters were measured monthly. Seedlings were harvested at monthly intervals and growth parameters of root system, stem and needle fractions were evaluated. The result showed that height of the seedlings grown at both of elevated $CO_2Xhigh$ nitrogen and elevated CO2×low nitrogen supplying treatments increased significantly more than that of at ambient CO2 treatments. Seedlings grown at elevated $CO_2Xhigh$ nitrogen produced more root biomass than at elevated $CO_2Xlow$ nitrogen and ambient $CO_2Xhigh$ nitrogen treatments. This result suggested that the root growth response of Picea koraiensis seedlings was greater in elevated $CO_2{\times}high$ nitrogen regime, which is very important for carbon sequestration in soil. $A_{max}$ of the seedlings grown at elevated $CO_2Xhigh$ nitrogen increased during the three months significantly, and $A_{max}$ of the seedlings grown at the other three treatments decreased significantly, suggesting that the interaction between elevated $CO_2$ and high nitrogen supplying stimulates the $A_{max}$ of Picea koraiensis. $A_{max}$ of the seedlings grown at elevated $CO_2Xlow$ nitrogen showed higher than other three treatments in the first month of the experiment, but decreased in succedent two months, suggesting that elevated $CO_2$ promotes the photosynthesis of the seedlings. However long term growth in elevated $CO_2Xlow$ nitrogen supplying condition resulted in an acclimatory decreased in leaf photosynthesis.

• Journal of Environmental Impact Assessment
• /
• v.19 no.6
• /
• pp.607-615
• /
• 2010

Urban green space is often at the centre of the debate on urban substantiality because it provides functions of space, e.g. for wildlife, recreation, growing vegetables, psychological wellbeing, social interaction, etc. Traditionally, the various functions of urban green spaces clearly show that green spaces contain important values that contribute to the overall quality of urban life. After Kyoto protocol, it has becoming important to more accurately evaluate carbon uptake by urban green space. Many studies have analyzed the benefits, costs, and carbon storage capacity associated with urban green space. These studies have been limited by a lack of research on urban tree biomass and carbon uptake by soil, such that estimates of carbon storage in urban systems. This study calculate more accurately the amount of carbon uptake by urban green space. This study also complement the existing methods to estimate the urban green space carbon uptake. It has been studied how to evaluate carbon uptake function of urban green space. The surface area of urban green space increased 5% by complemented method and carbon uptake is also increased. Based on this result, the carbon uptake per capita was analysed and compared to the area of carbon uptake. And this study discussed the reasons for the differences between the new and earlier estimates, as well as implications for our understanding of the global carbon cycle. In conclusion, these results could contribute as preliminary data to policy makers when climate change adaptation strategy is established.

• Journal of Korea Water Resources Association
• /
• v.31 no.2
• /
• pp.177-187
• /
• 1998

The spatially integrated model (SIM) which can evaluate temporal variation of groundwater quality is proposed in the stream-aquifer setting entered by nonpoint source contaminants. And the developed SIM included unsaturated soil zone and was tested against the spatially distributed model (SDM) of the coupled advection-dispersion and Richards equations for the various hydrologic and aquifer simulating conditions. The result of the comparison showed that the average concentration responses of saturated aquifer and groundwater outflow between the SIM and the SDM was in good agreement, except for the case of the large dispersivity ratio and thick aquifer system. And it is shown that for the cases of the large dispersivity ratio and thick aquifer system the performance of the nonlinear SIM is better than that of the linear SIM for evaluating the average concentration of groundwater outflow response.

• The Plant Pathology Journal
• /
• v.23 no.4
• /
• pp.239-244
• /
• 2007

MicroTom is a miniature tomato plants with various properties that make it as a model system for experiments in plant molecular biology. To extend its utility as a model plant to study a plant - bacterial wilt system, we investigated the potential of the MicroTom as a host plant of bacterial wilt caused by Ralstonia solanacearum. We compared the disease progress on standard tomato and MicroTom by two inoculation methods, root dipping and soil drenching, using a race 1 strain GMI1000. Both methods caused the severe wilting on MicroTom comparable to commercial tomato plant, although initial disease development was faster in root dipping. From the diseased MicroTom plants, the same bacteria were successfully reisolated using semiselective media to fulfill Koch's postulates. Race specific and isolate specific virulence were investigated by root dipping with 10 isolates of R. solanacearum isolated from tomato and potato plants. All of the tested isolates caused the typical wilt symptom on MicroTom. Disease severities by isolates of race 3 was below 50 % until 15 days after inoculation, while those by isolates of race 1 reached over 50% to death until 15 days. This result suggested that MicroTom can be a model host plant to study R. solanacearum - plant interaction.

• The Journal of Engineering Geology
• /
• v.22 no.4
• /
• pp.399-408
• /
• 2012

To estimate seismic source and soil-structure interaction more reliably, site amplification characteristics should be considered. Among the various estimation methods, we used Nakamura's method (1989) to estimate site amplification. This method was originally applied to background noise; however, it has recently been successfully applied to S-wave and Coda-wave energy, and is applied to S-waves in the present study. We used more than 180 observed ground motions from 23 macro-earthquakes and then analyzed site amplification characteristics at eight seismic stations. Each station showed characteristics of site amplification properties in the low-, high- and resonance-frequency ranges. Comparison of the present results with those of other studies provide successful information regarding the dynamic amplification of domestic site characteristics and site classification.