• 한국토양비료학회지
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• 제47권4호
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• pp.225-234
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• 2014

This study was carried out to investigate the sustainable agriculture of no-tillage technique including recycling of the ridge and the furrow of a field for following crops in Korea. No-tillage systems affect soil physical properties such as three phase (solid, liquid, and air phase) and distribution of soil granular. Solid ratio of subsoil in 3-year of no-tillage (NT) treatment was remarkably lower than that in conventional (CT, 2-year of no-tillage + 1-year of tillage) treatment, while air ratio of subsoil in NT remarkably increased. Bulk density of subsoil in NT remarkably decreased. Porosity of subsoil in NT remarkably increased. Deviation of air phase, bulk density, and porosity of top soil and subsoil in NT remarkably decreased in NT compared with CT. Solid phase ratio and liquid phase ratio in NT and CT had positive (+) correlation. Solid phase ratio and air phase ratio in NT and CT had negative (-) correlation, also liquid phase ratio and air ratio had negative (-) correlation. Bulk density and liquid ratio in soil had positive (+) correlation at top soil and subsoil in NT. Bulk density and air ratio in soil had negative (-) correlation in NT and CT. Porosity and liquid phase ratio had negative (-) correlation, r =1), the significant value was lower in NT than in CT. Porosity and air phase ratio had positive (+) correlation (r =1).

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.247-249
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• 2002

The transfer behaviors of three Polyarmatic hydrocarbons (PAHs) from soil to non-aqueous phase liquid (NAPL) were investigated. The three different PAHs were phenanthrene, anthracene, and pyrene. The used NAPLs were silicone oil and paraffine oil. The percentage of the remained PAHs into soil were similar without the relation to kinds of NAPLs. And the transfer of PAHs into NAPLs was fastened until 1 day as the increase of mixing rate but in the case of 450 rpm, the remained PAHs into soil was increased after 1 day because NAPLs was emulsified.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.124-127
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• 2003

Laboratory scale experiments on in-situ ozonation were carried out to delineate the effects of liquid phases, such as soil water and nonaqeous phase liquid (NAPL) on the transport of gaseous ozone in unsaturated soil. Soil water enhanced the transport of ozone due to water film effect, which prevent direct reaction between soil particles and gaseous ozone, and increased water content reduced the breakthrough time of ozone because of increased average linear velocity of ozone and decreased air-water interface area. Diesel fuel as NAPL also played a similar role with water film, so the breakthrough time of ozone in diesel-contaminated soil was significantly reduced compared with uncontaminated soil. However, ozone breakthrough time was retarded with increased diesel concentration, because of high reactivity of diesel fuel with ozone. In multiphase liquid system of unsaturated soil, the ozone transport was mainly Influenced by nonwetting fluid, diesel fuel in this study.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권3호
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• pp.65-73
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• 2015

The hydrofluoric acid (HF) leakage accident occurred on September 2012 in Gumi, Korea affected the surrounding soils and plants. In this study, we investigated fluoride migration in Gumi area through geochemical properties of soil-liquid phase (pore water F and water-soluble F). The concentrations of porewater F and water-soluble F were obtained from N.D (Not detected) to 9.79 mg/L and from 0.001 to 21.4 mg/L, respectively. F in pore water seemed to be affected by artificial and natural origin, and PHREEQC results implied that fluorite is F control factor. F concentrations of soil and soil-liquid phase did not exceed concern level of regulatory criteria and showed similar trends compared by previous studies. Therefore, F contents remained in the soil and soil-liquid phase were considered to be not affected by HF leakage accident.

• Journal of Ginseng Research
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• 제4권2호
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• pp.175-185
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• 1980

A study was made to clarify the topographical. and Physical characteristics of ginseng field in terms of soil science and to find the relationship between soil characteristics and ginseng growth, as well as yield of ginseng roots Forty nine farmer's red ginseng field of ginseng growing area were chosen for this study and investigated for two years. The results obtained were as follow. 1. Ginseng fie1ds with high yield which represent the more than 1.8kg of ginseng root per 3.2m2 were found in soil series of Bancheon, Yeongog, Weongog, etc. whose texture were the clay loam to clay soil. On the other hand, ginseng field with low yield were observed in soil series of seogto whose texture was loamy soil with high content of gravels. 2 Soil of ginseng field with high yield had higher content of clay. silt soil moisture and soil pore as compared with soils of low yields. These soil characteristics were positively correlated with stem length stem diameter and root weight of ginseng plsnt and negatively correlated with rate of missing plant 3. The adequate ranges of soil 3 phase from high yield ginseng field were 40 to 50% of solid Phase, 22 to 35% of liquid phase, 25 to 35% of gaseous phase in top soil and 45 to 55% of solid phase. 28 to 30% of liquid phase. 15 to 20% of gaseous phase in subsoil respectively.

• Applied Biological Chemistry
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• 제41권8호
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• pp.595-599
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• 1998

An analytical method was developed to determine tricyclazole residues in rice grain, straw, and soil using high-performance liquid chromatography (HPLC) with ultraviolet absorption detection. Tricyclazole was extracted with methanol from moist rice grain, straw, and soil samples. n-Hexane washing was employed to remove nonpolar co-extractives during liquid-liquid partition. Tricyclazole was then extracted with dichloromethane from alkaline aqueous phase, while acidic interferences remained in the phase. Dichloromethane extract was further purified by silica gel column chromatography prior to HPLC determination. Reverse-phase HPLC using an octadecylsilyl column was successfully applied to separate and quantitate the tricyclazole residue in sample extracts monitored at ${\lambda}_{max}$ 225nm. Recoveries from fortified samples averaged $95.5{\pm}3.0%\;(n=6),\;87.5{\pm}20.%\;(n=6),\;and\;84.3{\pm}2.8%$ (n=12) for rice grain, straw, and soil, respectively. Detection limit of the method was 0.02 mg/kg for rice grain and soil samples while 0.05 mg/kg for rice straw samples. The proposed method was reproducible and sensitive enough to evaluate the safety of tricyclazole residues in rice grain, straw, and soil.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.171-176
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• 2000

Bioremediation of hazardous hydrophobic organic compounds, such as polycyclic aromatic hydrocarbons (PAHs), is a major environmental concern due to their toxic and carcinogenic properties. Due to their hydrophobicity, the hydrophobic organic compounds are mainly associated with the soil organic matter or nonaqueous-phase liquids. A major question concerns the relationships between biodegradation and sorption. This work develops and utilizes a non- steady state model for evaluating the interactions between sorption and biodegradation of phenanthrene, a 3-ring PAH compound, in soil-slurry systems. The model includes sorption/desorption of a target compound, its utilization by microorganisms as a primary substrate existing in the dissolved phase and/or the sorbed phase in biomass and soil, oxygen transfer, and oxygen utilization as an electron acceptor. Biodegradation tests with phenanthrene were conducted in liquid and soil-slurry systems. The soil-slurry tests were performed with very different mass transfer rate: fast mass transfer in a flask test at 150 rpm, and slow mass transfer in a roller-bottle test at 2 rpm. In the slurry tests, phenanthrene was degraded more rapidly than in liquid tests, but with a similar rate in both slurry systems. Modeling analyses with several hypotheses indicate that a model without biodegradation of compound sorbed to the soil was not able to account for the rapid degradation of phenanthrene, particularly in the roller bottle slurry test. Reduced mass-transfer resistance to bacteria attached to the soil is the most likely phenomenon accounting for rapid sorbed-phase biodegradation.

• Geomechanics and Engineering
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• 제33권2호
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• pp.175-182
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• 2023

In general, the design of structures and its construction processes are fundamentally dependent on their foundation and supporting ground. Thus, it is imperative to understand the behavior of the soil under certain stress and drainage conditions. As it is well known that certain characteristics and behaviors of soils with fines are highly dependent on water content, it is critical to accurately measure and identify the status of the soils in terms of water contents. Liquid limit is one of the important soil index properties to define such characteristics. However, liquid limit measurement can be affected by the proficiency of the operator. On the other hand, dynamic properties of soils are also necessary in many different applications and current testing methods often require special equipment in the laboratory, which is often expensive and sensitive to test conditions. In order to address these concerns and advance the state of the art, this study explores a novel method to determine the liquid limit of cohesive soil by employing video-based vibration analysis. In this research, the modal characteristics of cohesive soil columns are extracted from videos by utilizing phase-based motion estimation. By utilizing the proposed method that analyzes the optical flow in every pixel of the series of frames that effectively represents the motion of corresponding points of the soil specimen, the vibration characteristics of the entire soil specimen could be assessed in a non-contact and non-destructive manner. The experimental investigation results compared with the liquid limit determined by the standard method verify that the proposed method reliably and straightforwardly identifies the liquid limit of clay. It is envisioned that the proposed approach could be applied to measuring liquid limit of soil in practical field, entertaining its simple implementation that only requires a digital camera or even a smartphone without the need for special equipment that may be subject to the proficiency of the operator.

• 유기물자원화
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• 제17권3호
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• pp.40-47
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• 2009

토양으로 유출된 비수용상액체(nonaqueous phase liquid; NAPL)의 제거를 위한 알코올 희석 세정공정의 기술개발을 위하여 3-D 토양탱크에서 NAPL 흡수 및 비흡수 알코올 단독 또는 공기 동시 주입공정에 의한 벤젠 NAPL 제거 효과를 평가하였다. 37L 규모의 토양탱크에 729mL의 벤젠을 주입하고 70%에탄올 (NAPL 비흡수 알콜)과 40%이소 프로판올(NAPL 흡수 알콜)을 탱크 하부에 설치된 주입정에 주입하고 상부의 추출정으로부터 자유상 NAPL 및 수용액을 추출하였다. 그리고 알코올 주입과 공기를 동시 주입하여 기존 토양칼럼실험에서 확인된 공기 동시주입시 화학세정 증대 효과를 아울러 평가하였다. 70% 에탄올 및 40% 이소-프로판올에 의한 토양탱크 세정공정 결과 전체 벤젠 제거율의 과반수는 자유상 NAPL 형태로 제거되었다. 알코올의 NAPL 흡수 특성에 따라 벤젠 제거 특성이 현저히 다르게 나타난 토양칼럼결과와 달리 3-D공정에서는 알코올 NAPL 흡수특성의 영향이 매우 적게 나타났다. 70%에탄올과 공기 동시 주입에 의한 벤젠 제거 증대 효과는 3-D 토양탱크 실험결과에서도 여전히 확인되었다. 그러나 NAPL 흡수 알코올인 40% 이소-프로판올은 공기 동시 주입에 의한 벤젠 제거 증대효과가 여전히 미미하게 나타났다. 3-D 토양탱크 실험결과 화학세정공정에 의한 NAPL제거에 있어 가장 중요한 인자는 추출정의 NAPL 및 유출수 추출능력이었다. 즉 토양내 효과적인 NAPL 정화를 위해서는 화학적인 작용에 의하여 이동된 자유상 NAPL 및 수용액을 밖으로 효율적으로 추출할 수 있는 공정이 필요하다.

• 한국환경농학회지
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• 제23권4호
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• pp.251-257
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• 2004

Analytical methods were developed to determine cyclosulfamuron residues in soil, water, rice grain and straw using high-performance liquid chromatography (HPLC) with ultraviolet absorption detection. In these methods, cyclosulfamuron was extracted with aqueous $Na_2HPO_4$/acetone and acetone/methanol mixture from soil and rice samples respectively. Liquid-liquid partition coupled with ion-associated technique, Florisil column chromatography, and solid-phase extraction (SPE) were used to separate cyclosulfamuron from interfering co-extractives prior to HPLC analysis. For water sample, the residue was enriched in $C_{18}$-SPE cartridge, cleaned up in situ, and directly subjected to HPLC. Reverse-phase HPLC under ion-suppression was successfully applied to determine cyclo-sulfamuron in sample extracts with the detection at its ${\lambda}_{max}$ (254 nm). Recoveries from fortified samples averaged $87.8{\pm}7.1%$ (n=12), $97.3{\pm}7.2%$ (n=12), $90.8{\pm}6.6%$ (n=6), and $78.5{\pm}6.7%$ (n=6) for soil, water, rice grain and straw, respectively. Detection limits of the methods were 0.004 mg/kg, 0.001 mg/L, 0.01 mg/kg and 0.02 mg/kg for soil, water, rice grain and straw samples, respectively.