• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1998년도 가을 학술발표회 논문집
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• pp.145-150
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• 1998

• 한국자원식물학회지
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• 제32권6호
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• pp.735-742
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• 2019

This study investigated a suitable method that could be applied for Asian chain fern [Woodwardia japonica (L. f.) Sm.] to propagate gametophytes and promote sporophyte formation. The gametophytes used in all experiments were obtained from germinated spores in vitro and were subcultured at 8-week intervals. The most appropriate media for gametophyte propagation was identified by culturing 300 mg of gametophyte in Murashige and Skoog (MS) basal medium (1/8, 1/4, 1/2, 1, 2), and Knop medium for 8 weeks. As a result, fresh weight of the gametophyte was increased by 56.7-fold on MS medium. Moreover, antheridium formation as well as gametophyte growth was improved on MS medium, especially. To improve the sporophyte formation ex vitro, 1.0 g of gametophyte was ground with distilled water and spread on eight combinations onto four different culture mediums, such as bed soil, peat moss, perlite and decomposed granite. Then generation and growth of sporophytes were investigated after cultivation for 10 weeks. As a result of this experiment, peat moss had a promotive effect of sporophyte formation at single-use and mixed culture soils. In particular, a mixture of bed soil, peat moss and perlite in a 1:1:1 ratio (v/v/v) led to the accelerated formation (782.5 ea/pot) and the frond growth of sporophytes. This included increases in length and width of fronds. However, promotive effect of gametophyte growth and sporophyte formation was not found at single-use and treatment with high ratio of bed soil.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권5호
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• pp.9-17
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• 2011

Positive effect of multiple-PGPR (Plan Growth Promoting Rhizobacteria), isolated from heavy metal contaminated soil, on the germination of Barnyard grass (Echinochloa crus-galli var. frumentacea) was quantitatively estimated in 5 heavy metal (Cd, As, Ni, Cu, and Pb) contaminated liquid medium. The $EC_{50}$ value for respective heavy metal was estimated by TSK (Trimmed Speraman-Karber) model based on germination rate. The results showed overall increase in $EC_{50}$ with PGPR inoculation. The $EC_{50}$ value increased 1.4% from 96.0 mg/L (control) to 97.4 mg/L (PGPR-treated) in As contaminated medium. In Ni contaminated medium, the $EC_{50}$ value increased 31.9% from 148.0 mg/L (control) to 195.2 mg/L (PGPR-treated), while the $EC_{50}$ showed 4.8% increase from 63.4 mg/L (control) to 66.5 mg/L (PGPR-treated) in Cu medium. Overall seedling growth was stronger in the PGPR treated seeds than that in the control, but positive effect on seedling growth was not conspicuous. At effective concentration of 100 mg/L, the average seedling length of the PGPR treatment in As, Cd, Cu, and Ni medium, respectively, was 1.13, 0.14, 0.40, and 0.06 cm longer than that in the control. However, the increase of seedling growth was statistically insignificant (p < 0.05). These results suggest that inoculation of the isolated-PGPR exerts positive effects on seed germination by reducing heavy metal toxicity and can be an effective tool for application of phytoremediation on heavy metal contaminated soils.

• Geomechanics and Engineering
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• 제15권2호
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• pp.793-803
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• 2018

Based on the theory of porous media, an interaction system of a floating pile and a saturated soil in cylindrical coordinates subjected to vertical harmonic load is presented in this paper. The surrounding soil is separated into two distinct layers. The upper soil layer above the level of pile base is described as a saturated viscoelastic medium and the lower soil layer is idealized as equivalent spring-dashpot elements with complex stiffness. Considering the cylindrically symmetry and the pile-soil compatibility condition of the interaction system, a frequency-domain analytical solution for dynamic impedance of the floating pile embedded in saturated viscoelastic soil is also derived, and reduced to verify it with existing solutions. An extensive parametric analysis has been conducted to reveal the effects of the impedance of the lower soil base, the interaction coefficient and the damping coefficient of the saturated viscoelastic soil layer on the vertical vibration of the pile-soil interaction system. It is shown that the vertical dynamic impedance of the floating pile significantly depends on the real stiffness of the impedance of the lower soil base, but is less sensitive to its dynamic damping variation; the behavior of the pile in poro-visco-elastic soils is totally different with that in single-phase elastic soils due to the existence of pore liquid; the effect of the interaction coefficient of solid and liquid on the pile-soil system is limited.

• 대한원격탐사학회지
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• 제11권3호
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• pp.117-127
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• 1995

본 논문에서는 지표면의 유효 토양 수분함유량의 적정한 값을 추출하는 몇가지 방법을 소개하고 그 방법들을 서로 비교하였다. 지표면의 꼭대기 층은 비교적 말라 있고, 밑바닥 층은 젖 어 있어서 종단면으로 봤을 때 토양은 대개 균일하지 않은 수분함유량 분포를 갖는다. 이러한 비 균일적인 토양의 수분함유량을 봤을 때 토양은 대개 균일하지 않은 수분함유량 분포를 갖는다. 이러한 비균일적인 토양의 수분함유량을 어떤 평균적인 값으로 나타낸 것이 유효 수분함유량이 다. 이 유효 수분함유량을 구하는 간단한 방법 중의 하나는 층층이 측정한 수분함유량의 산술 평 균을 취하는 것이다. 다른 방법으로는 균일한 지표면과 비균일한 지표면의 침투 두께를 각각 계 산하고 비교하여 유효 수분함유량을 얻는 방법이 있다. 또 다른 방법은 균일 지표면과 비균일 지 표면에서 각각 반사율을 계산하고 비교하여 유효 수분함유량을 구한다. 이러한 방법들이 서로 비 교되었고, 특히 반사율 적용법이 좀 더 자세하게 연구되었는데 그 이유는 실제 레이다 산란은 전 파의 침투보다는 반사에 의해 좌우되기 때문이다.

• 대한환경공학회지
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• 제35권8호
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• pp.607-612
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• 2013

토양 생태위해성평가는 식물류, 지렁이류, 선충류, 곤충류 등 일부 영양 단계에 국한된 토양독성자료를 활용하고 있다. 토양독성자료의 생물종 확대를 위해 토양 환경에서의 주요 생산자인 조류가 우선적으로 고려되어야 한다. 본 연구에서는 토양 관련 조류독성 연구동향을 분석하기 위해 국제 학술 논문을 대상으로 토양 관련 시험종, 노출매체 등에 초점을 맞춰 연구 사례를 수집하였으며, 시험매체, 시험종, 시험물질, 시험방법 등의 특성 중심으로 분석하였다. 현재까지 토양 관련 조류독성 연구에 사용된 생물종은 8종(Pseudokirchneriella subcapitata, Chlorella vulgaris, Scenedesmus bijugatus, Chlorococcum infusionum, Scenedesmus subspicatus, Nostoc linckia, Synechococcus elongatus, and Chlorococcum sp.)으로 제한적이고, 독성 종말점은 세포계수나 광합성 색소 측정에 국한되어 있다. 또한 노출매체는 액체배지, 토양추출액(soil extract), 토양공극수(porewater), 한천배지, 토양 등 총 5종으로, 액체배지와 토양추출액이 대부분을 차지하며, 토양에서 분리된 조류를 이용하거나 토양 추출액을 이용하는 연구가 대부분이라 토양 매체에서의 직접적인 연구는 미비하다. 따라서 토양 오염으로 인한 생태계 건강성 저하를 방지하기 위하여 필요한 생태위해성평가는 토양 매체에서의 전반적인 종 민감도 분포 파악이 선행되어야 하므로, 토양 관련 조류 시험종 및 종말점 개발이 필요하다.

• 환경영향평가
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• 제14권4호
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• pp.147-155
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• 2005

This study was designed to investigate the effect of plant as a botanical air purification on the indoor pollution by formaldehyde. Three indoor plants such as Dracaena marhginata, Spathiphyllum and Dracaena reflexa, were placed in the artificially contaminated reactor under laboratory condition. Both plant and soil effects on removal of formaldehyde from contaminated indoor air were observed. Reductions in the formaldehyde levels appeared to have been associated with soil medium factors as well as plant factors. The effect of soil on formaldehyde reduction was high in the early stage of the experiment and the results suggest that sorption could be more important factor than microbial degradation in the initial dissipation of contaminants in the soil. It was suggested that the effect of plant on formaldehyde reduction might be related to the plant species, total leaf surface area of plant, degree of contribution of soil medium, and exposed concentration level. The results of this study showed that air purification using plants is an effective means of reduction on indoor formaldehyde level, though, utilization of soil media with high sorption capacity and/or supplementary purifying aids were also suggested when the source is continuous or exposed concentration level is high.

• Geomechanics and Engineering
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• 제13권4호
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• pp.601-619
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• 2017

Cantilever retaining wall movements generally depend on the intensity and duration of ground motion, the response of the soil underlying the wall, the response of the backfill, the structural rigidity, and soil-structure interaction (SSI). This paper investigates the effect of material properties on seismic response of backfill-cantilever retaining wall-soil/foundation interaction system considering SSI. The material properties varied include the modulus of elasticity, Poisson's ratio, and mass density of the wall material. A series of nonlinear time history analyses with variation of material properties of the cantilever retaining wall are carried out by using the suggested finite element model (FEM). The backfill and foundation soil are modelled as an elastoplastic medium obeying the Drucker-Prager yield criterion, and the backfill-wall interface behavior is taken into consideration by using interface elements between the wall and soil to allow for de-bonding. The viscous boundary model is used in three dimensions to consider radiational effect of the seismic waves through the soil medium. In the seismic analyses, North-South component of the ground motion recorded during August 17, 1999 Kocaeli Earthquake in Yarimca station is used. Dynamic equations of motions are solved by using Newmark's direct step-by-step integration method. The response quantities incorporate the lateral displacements of the wall relative to the moving base and the stresses in the wall in all directions. The results show that while the modulus of elasticity has a considerable effect on seismic behavior of cantilever retaining wall, the Poisson's ratio and mass density of the wall material have negligible effects on seismic response.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.81-85
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• 2002

The possibility of simultaneous analysis of 24 pesticides out of 30 residual pesticides which are subjected to test in the golf courses was examined. The utility of the simultaneous analysis of multi-residue pesticides was evaluated by recovery test through a standard addition method of pesticides in water, soil, and lawn grass. The experimental results of the recovery rates for individual pesticides are as follows : The number of pesticide of which average recovery was over 70% regardless of medium was 16 pesticides. These pesticides were composed of 8 organophosphorus pesticides(Chlorpyrifos, Chlorpyrifos-methyl, Diazinon, EPN, Fenitrothion, Phenthoate, Phosalone, and Toclofos-methyl). 4 organochlorinated pesticides(Daconil, Captan, Endosulfan, and Tetradifon), 2 pyrethroid pesticides(Fepropathrin, Lambda-cyhalothrin) and 2 other pesticides(Bromopropylate, Pendimethalin). On the other hand, in case of Dicofol, average recovery by medium was over 70% for water and lawn grass but was only 53.3% for soil. Therefore, the simultaneous analytical method applied in this experiment is not appropriate for analysis of Dicofol in soil. Furthermore, among 7 pesticides, 2 pesticides(Amitraz and Pyraclofos) showed that theirs average recovery rates deviated from criteria(70~130%) at almost all media, while 5 pesticides(Bensulide, Deltamethrin, Iprodione, Phosphamidon and Tralomethlin) were not detected from all media by selected GC detector(NPD or ECD).

• Weed & Turfgrass Science
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• 제5권2호
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• pp.88-94
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• 2016

Vehicular traffic on turf results in loss of green cover due to direct tearing of shoots and indirect long-term soil compaction. Protection of turfgrass crowns from wear could increase the ability of turf to recover from heavy traffic. Plastic turfpavers have been installed in trafficked areas to reduce soil compaction and to protect turfgrass crowns from wear. The objectives of this study were to evaluate traffic performance of turfgrasses (Zoysia matrella and Axonopus compressus) and soil mixture (high, medium and low sand mix) combinations on turf-paver complex. The traffic performance of turf and recovery was evaluated based on percent green cover determined by digital image analysis and spectral reflectance responses by NDVI-meter. Bulk density cores indicated significant increase in soil compaction from medium and low sand mixtures compared to high sand mixture. Higher reduction of percent green cover was observed from A. compressus (30-40%) than Z. matrella (10-20%) across soil mixtures. Both turf species displayed higher wear tolerance when established on higher sand (>50% sand) than low sand mixture. Positive turf recovery was also supported by complementary spectral responses. Establishment of Zoysia matrella turf on turfpaver complex using high sand mixture will result in improved wear tolerance.