• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2005년도 학술발표회 논문집
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• pp.137-144
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• 2005

Seismic responses of a building are affected due to the site soil conditions. In this study, linear time history seismic analysis and nonlinear pushover static seismic analysis were performed to estimate the base shear forces of the 3, 5 and 7-story steel structure buildings considering the rigid and soft soil conditions. According to the study results, the steel structure buildings designed for the gravity loads and wind load showed the elastic responses with the moderate earthquake of 0.11g, and the soft soil layer increased the displacement and the base shear force of a building. Therefore it is more resonable to perform an elastic seismic analysis of a building structure with the moderate earthquakes considering the characteristics of the soft soil layer.

• 한국철도학회논문집
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• 제3권3호
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• pp.101-108
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• 2000

In this study, we tested hybrid pilot system combined with soil vapor extraction and bioventing methods on the contaminated railroad soil. So, we found out the remediability and operating conditions. Air permeability(k) and gas phase(O$_2$/CO$_2$/VOCs) level trend are very important to determine the remediation rate of the contaminated sites. Throughout hybrid pilot test on different conditions, the range of air permeability(k) was 1985∼1194 darcy. The tests results in hybrid system was appropriate on this test sites, and the suitable injection air flow rate was 3.5㎥/hr. So, we suggested a basic data for the remediation and management of contaminated railroad soil.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2001년도 Proceedings of the 3rd Annual Meeting of Yellow Sea Environment
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• pp.11-16
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• 2001

If microorganisms are injected into porous medium such as soils along with appropriate substrate and nutrients, soil pore size and shape are changed from the initial condition as a result of biofilm formation, which make hydraulic conductivity reduced. In this research, hydraulic conductivity reduction was measured after specific bacterium or fungus was inoculated into soil pore. Hydraulic conductivity was decreased to 10 % ∼ 1 % and maintained constant while substrate was provided. Under the adverse conditions such as no substrate, chemical solution permeation, and freeze-thaw cycles, hydraulic conductivity was increased 30∼50%. Hydraulic conductivity decrease of fungus-soil mixture was faster than that of bacterium-soil mixture. Fungus-soil mixture, however, was more sensitive to the adverse conditions.

• 한국환경과학회지
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• 제16권11호
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• pp.1247-1255
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• 2007

Soil biofiltration is an environmentally-sound technology for elimination of VOCs, odorous and $NO_X$ compounds from a low concentration, high volume waste gas streams because of its simplicity and cost-effectiveness. This study investigated the optimal mixture fraction of briquet ash, compost, soil and loess for $NO_X$ degradation. Extreme vertices design was used to examine the role of four components on $NO_X$ degradation. Under our experimental conditions, 74.5% of $NO_X$ degradation was observed, using a model mixture(25% briquet ash, 10% compost, 30% soil and 40% loess) containing 100 ppb of NO. It was shown that experimental design analysis could allow selecting optimal conditions in such biodegradation processes in this study.

• 드라이브 ㆍ 컨트롤
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• 제17권4호
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• pp.133-140
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• 2020

Traction performance of a tractor varies depending on soil conditions. Sinkage and slip of the driving wheel for tractor frequently occur in a reclaimed land. The objective of this study was to develop a tractor suitable for a reclaimed land. Traction performance was evaluated according to soil conditions of reclaimed land and paddy field. Field experiments were conducted at two test sites (Fields A: paddy field; and Field B: reclaimed land). The tractor load measurement system was composed of an axle rotation speed sensor, a torque meter, a six-component load cell, GPS, and a DAQ (Data Acquisition System). Soil properties including soil texture, water content, cone index, and electrical conductivity (EC) were measured. Referring to previous researches, the tractor traveling speed was set to B3 (7.05 km/h), which was frequently used in ridge plow tillage. Soil moisture contents were 33.2% and 48.6% in fields A and B, respectively. Cone index was 2.1 times higher in field A than in field B. When working in the reclaimed land, slip ratios were about 10.5% and 33.1% for fields A and B, respectively. The engine load was used almost 100% of all tractors under the two field conditions. Traction powers were 31.9 kW and 24.2 kW for fields A and B, respectively. Tractive efficiencies were 83.3% and 54.4% for fields A and B, respectively. As soil moisture increased by 16.4%, the tractive efficiency was lowered by about 28.9%. Traction performance of tractor was significantly different according to soil conditions of fields A and B. Therefore, it is necessary to improve the traction performance of tractor for smooth operations in all soil conditions including a reclaimed land by reflecting data of this study.

• 한국지하수토양환경학회지:지하수토양환경
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• 제6권2호
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• pp.23-30
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• 2001

본 주상실험은 오염된 토양에서의 계면활성제 용액상태에 따른 복원 효과를 조사하기 위하여 실행되었다. 농도, pH, 온도, 그리고 용액의 유속을 달리하여 실험을 수행하였다. 실험에 사용된 오염물질은 톨루엔, 토양시료는 Iowa Fruitfield sandy soil, 그리고 계면활성제는 Sodium diphenyl oxide disulfonate (DOSL)이었다. 실험결과, 최적 조건은 다음과 같이 구해졌다. 계면활성제의 농도는 4 %(v/v), pH는 10, 온도는 $20^{\circ}C$, 그리고 유속은 4 mL/min이었다. 이 조건이 모두 만족하는 상태에서는 95 %의 톨루엔이 제거되었으며 이는 다른 조건에서보다 6~l9 %의 상승효과를 보인 것이다. 본 실험에서 보여준 계면활성제 조건은 톨루엔으로 오염된 대수층의 복원에 매우 유용한 자료가 될 것이다.

• 한국환경과학회지
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• 제13권10호
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• pp.883-890
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• 2004

The purpose of this study is to survey and analyze the growth, management and surrounding environment of the big and old trees in Kyoungju-si or the cultural assets alive in our history, and thereby, provide for some data useful to their reasonable protection and use of their surrounding areas. As a result of surveying the growth conditions of the big and old trees, it was found that the height of new grass was 10.5cm on average, the activity scale of the wood was 7.2k$\Omega$, the soil hardness was $16.7kg/cm^2$, the soil acidity was pH 4.8, and the soil moisture was $13.3\%$. Such findings suggest that the soil has been acidified by people's frequent passages, but that the other growth conditions are more or less normal. Hence, it is desirable to secure a sufficient space around the trees or reduce people's stamping pressure with some mechanisms. On the other hand, the visible conditions of the trees were found more or less normal, but many trees remained cut or barked (with some cavities), requiring an optimal treatment or measure. Lastly, as the population has decreased in the suburban traditional villages, the surrounding environment seems to be less vulnerable to people's frequent visits. Nevertheless, in consideration of the fact that there are only a few public space for the villagers, it is deemed necessary to rearrange or maintain some parts of the surrounding environment as public space for villagers or hikers.

• Geomechanics and Engineering
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• 제37권5호
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• pp.511-525
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• 2024

Micropiled raft has been used to support the existing and new structures or to provide the seismic reinforcement of foundation systems. Recently, research on micropile or micropiled raft has been actively conducted as the usage of micropile has increased, and the reinforcement effect of pile for the raft, the pile installation methods, and methods for calculating the bearing capacity of micropiled raft have been proposed. In addition, existing research results show that the behavior of this foundation system is different depending on the pile conditions and can be greatly influenced by the characteristics of the upper or lower ground depending on the conditions of pile. In other words, considering that the micropile is a friction pile, it can be predicted that the reinforcing effect of micropile for the raft and the bearing capacity of micropiled raft may depend on the cohesion of upper soil layer depending on the pile conditions. However, existing studies have limitations in that they were conducted without taking this into account. However, existing studies have limitations as they have been conducted without considering these characteristics. Accordingly, this study investigated the reinforcing effect of micropile and the bearing characteristics of micropiled raft by varying the cohesion of upper soil layer and the stiffness of pile which affect the behavior of micropiled raft. In this results, the reinforcing effect of micropile on the raft also increased as the cohesion of soil layer increased, but the reinforcing effect of pile was more effective in ground conditions with decreased the cohesion. In addition, the relationship between the axial stiffness of micropile and the bearing capacity of micropiled raft was found to be a logarithmic linear relationship. It was found that the reinforcing effect of micropile can increase the bearing capacity of raft by 1.33~ 3.72 times depending on the cohesion of soil layer and the rigidity of pile.

• 한국염색가공학회지
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• 제8권1호
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• pp.83-89
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• 1996

Carbon black has been used as a particulate soil to prepare artificial soiled fabrics for detergent study but it has two major defects. The one is the difficulty of quantitative analysis of carbon black for evaluate the detergency, the other is that there is no reliable correlation between the removal of carbon black and oily soil which is the major component of natural soil. In this study ferric oxinate was used as a particulate soil since it is in black color and can be soiled on fabric by suspension in water or by solution in chloroform and it is easily analysed quantitatively by extracting it from soiled fabric with chloroform to get correct value of soil removal. The characteristics of soil removal of ferric oxinate were compared with that of carbon black and Sudan black, an oil soluble dye, which had been proved that it's detergency correlated with that of oily soil The soil removal of ferric oxinate and Sudan black estimated from quantitative analysis and from K/S value were in good agreement whereas the result calculated by simple reflectance was consistently low. The soil removal of ferric oxinate was exceeded from that of carbon black without regard to surfactants, Triton and Las, but the effect of washing conditions such as temperature and washing time on soil removal of both soils with different suffactants showed no considerable difference. Though the soil removal of Sudan black was little effected by the conditions, the soil removal in Triton exceeded considerably that of in Las, which is the characteristic of oily soil. Thus the soil removal of Sudan black was in good agreement with ferric oxinate in Triton, a non-ionic surfactant, and with carbon black in Las, an artionic surfactant. We concluded that ferric oxinate is a more realistic model particulate soil for artificial soiled cotton fabric washed with non-ionic surfactant than carbon black.

• 한국자원식물학회지
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• 제22권6호
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• pp.528-534
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• 2009

The study of germination and seedling growth characteristics of Neem under different soil and environment conditions was undertaken. The seed germination started 8 days after sowing in commercial bed soil, whereas, delayed germination was observed in sandy-loam (15 days) and sandy (19 days) soil. The highest germination (73.33%) was observed in commercial bed soil in green house, whereas, the lowest germination was observed in sandy soil (16.67%) and sandy-loam soil (8.33%). The seeds in the open field (sandy soil) also showed poor (10%) germination. The mean number of germination seed/day (GD) and seed germination vigor rate (GV) both were highest in the commercial bed soil with 0.733% and 16.67% respectively in the green house, whereas sandy and sandy-loam soil in green house and open field (sandy soil) all showed much lower GD and GV values. The seedling characteristics of nursery revealed that the seedling grown in the growth chamber in commercial bed soil was significantly higher in all the parameters comparing to others grown in green house and open field. The growth was nearly 7 fold in the chamber compared to that of the green house nursery observed in three months old seedlings. Likewise, HPLC analysis revealed that the green house grown seedling contain higher quantity of pigments compare to the chamber grown seedlings. Among the soils used the commercial soil alone or in combination with sandy and sandy-loam soil in the ratio of 2:1:1 respectively with the temperature of $27{\pm}2^{\circ}C$ showed better for Neem nursery preparation.