• Korean Journal of Soil Science and Fertilizer
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• v.14 no.4
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• pp.242-249
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• 1982

Effects of lime and ameliolating materials on decreasing available soil cadmium were studied, applying the amendments to Cd pre-and post-treated soils. Soil sttreated with Cd were placed in pots and kept under field moisture condition, summer through winter in 1981. The results of soil analysis made 40 to 60 days after the Cd treatment are as follows ; 1. Greater amount of Cd was extracted by 0.1N-HCl or 2% Citric acid than N-AcNH4 solution. More Cd was dissoluted by 0.1-HCl than 2% Citric acid. No Cd was extracted by pure water. Showing a wide variance in the amount of extractable Cd among treatments (amendments), the $N-AcNH_4$ solution seemed to be the most effective extracting solution of available soil cadmium. 2. Calcium hydroxide was the most effective materials in reducing $N-AcNH_4$ extractable Cd, followed by calcium carbonate and calcium silicate. 3. Superphosphate is also effective in reducing exchangeable cadmium. The reduction seemed to be attributed to the precipitation of cadmium phosphate. 4. The exchangeable cadmium by $N-AcNH_4$ was large in the soil pH range of 6.0 and 6.5, and it decreased as the soil pH became far apart from these values. The decrese of exchangeable Cd at low pH seemed to be related to the increase of $Mn^{+{+}}$ and that at the high pH to the precipitation as Cd-hydroxide.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.3
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• pp.163-168
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• 1981

The studies were carried out to examine the effect of soil improvement agents, such as lime, wollastonite and phosphate, in reducing the damage caused by hydrogen fluoride gas to the vegetative growth of rice. The yield loss, damage rate of the plant leaves, the fluoride and silicate concentrations of the plants were measured. The results obtained are summarized as follows : 1. Of various levels of added lime and wollastonite, the best were found to be neutralized lime plus lime 150kg/10a, and wollastonite 150kg/10a. 2. Added fluoride increased the fluoride content of the plant and the damage rate of the plant leaves, and the yield was greatly decreased. 3. The silicate concentration at harvesting period was also increased by high amounts of fluoride in the plant during vegetative growth. 4. Increasing the amount of added lime increased the watersoluble silicate concentration in the soil. The silicate content of the plant showed the same tendency.

• Journal of the Korean GEO-environmental Society
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• v.21 no.12
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• pp.29-34
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• 2020

Reinforced earth retaining walls were developed in France in the 1970s and began to be applied in earnest to Korea in the 1990s. And now, about 1,300 reinforced soil retaining walls support the embankment of highways and bridge connections. The reinforced earth retaining wall construction technology has evolved day by day, and in recent years the reinforced earth retaining wall itself has been developed and introduced as a demonstration. However, various damages are constantly occurring in the reinforced earth retaining walls constructed throughout the highway. The cause of this was analyzed as minor defects in the design, construction, and maintenance stages. The solution for this is a change in perception of the importance of each individual process, but this does not form overnight. In this study, 30 years have passed since the introduction of the reinforced soil retaining wall on the highway, the damage cases were analyzed and categorized that have occurred in the reinforced soil retaining wall so far, and attempted to present a confrontation. As a result, the damage occurring on the reinforced soil retaining wall was divided into 10 types, and the causes and countermeasures in the design, construction, and maintenance stages for each were derived.

• Journal of the Korean Society of Clothing and Textiles
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• v.12 no.3 s.28
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• pp.383-390
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• 1988

To investigate the soil-redeposition and color change on dry-cleaning, the white and, dyed, fabrics of cotton, silk, polyester and viscose rayon were put into ordinary commercial dry-cleaning machine with soiled cloths. The solvents used were hydrocarben, perchloroethylene and fluorocarbon. From the result, we obtained the following conclusions by examining soil-redeposition, color difference of fabrics and tenacity of cotton fabric. 1. In case of white fabrics, as a whole, perchloroethylene shows the lowest soil redeposition. When distillation process is adopted, the rate of soil redeposition is lowered. with hydrocarbon sdvent. The order of soil redeposition rate of fibers are following; cotton> viscose rayon> silk> polyester. 2. In case of dyed fabrics, the color difference between soil redeposited fabrics and originals ($\delta\;E_1$) is similar with white fabrics in pattern, and the order is cotton, viscose rayon, silk and polyester. The color difference between fabrics, treated by pure solvents and originals ($\delta\;E_2$ ) is also validated as a little. It seems to be due to the bleeding of dyestuffs from fabrics. 3. There is a little change of tenacity of cotton fabrics by dry-cleaning with perchloroethylene solvent. It is supposed that the damage is more influenced the repetitive mechanical action during dry-cleaning than by acidity of the solvent having the acid value of 0,14.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.4
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• pp.203-214
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• 2017

Environmental toxicity due to cadmium (Cd) pollution in croplands causes critical problems worldwide. Rice (Oryza sativa L.) is an important crop in Asia, including South Korea, and numerous studies have evaluated the relationship between Cd and antioxidants to alleviate Cd uptake from the soil into plants. However, information about the relationship between phosphorus (P) and antioxidants in rice seedlings is still limited with regard to Cd phytotoxicity. We therefore investigated the physiological responses of rice (Oryza sativa L. cv 'Dongjin') seedlings to Cd toxicity and the effect of P application on reactive oxygen species (ROS) and antioxidant changes. The exposure of rice seedlings to $30{\mu}M$ Cd inhibited plant growth; increased the contents of superoxide, hydrogen peroxide, and malondialdehyde; and induced Cd uptake by the roots and leaves. Application of P to Cd-exposed seedlings decreased Cd-induced oxidative stress by enhancing the capacity of ascorbate (AsA) production and ROS-scavenging, and decreased Cd transfer from the roots to the leaves. These results suggest that P application alleviated Cd-induced growth inhibition and oxidative damage by restricting Cd translocation from the roots to the leaves and maintaining sufficient levels of AsA.

• Structural Engineering and Mechanics
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• v.31 no.1
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• pp.75-91
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• 2009

It is known that retaining walls were severely damaged as well in the most recent earthquakes having occurred in the countries in the active seismic belts of the world. This damage can be ascribed to the calculation methods used for the designs of retaining walls in the event of their constructions and employment having been accurately carried out. Generally simplified pseudo-static methods are used in the analysis of retaining walls with analytical methods and soil-structure interaction are not considered. In view of these circumstances, in this article by taking soil interaction into consideration, linear and nonlinear behaviours of retaining walls are analyzed with the assistance of LUSAS which is one of the structural analysis programs. This investigations are carried out per LUSAS which employs the finite element method as to the Erzincan (1992) Earthquake North-South component and the obtained findings are compared with the ones obtained from the method suggested in Eurocode-8, which is still effective today, and Mononobe-Okabe method. Not only do the obtained results indicate the distribution and magnitude of soil pressures are depend on the filling soil but on the foundation soil as well and nonlinear effects should be considered in designs of these walls.

• Geomechanics and Engineering
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• v.23 no.4
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• pp.365-379
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• 2020

One of the leading causes for the damage of various underground structures during an earthquake is soil liquefaction, and among this liquefaction-induced uplift of these structures is a major concern. In this study, finite-difference modelling is carried out to study the liquefaction-induced uplift of an underground structure of 5 m diameter (D) with and without the replacement of the in-situ fine sand around the structure with the coarse sand. Soil replacements are carried out by three methods: replacement of soil above the structure, around the structure, and below the structure. The soil behaviour is represented using the elastic-perfectly plastic Mohr-Coulomb model, where the pore pressures were computed using Finn-Byrne formulation. The predicted pore pressure and uplift of the structure due to sinusoidal input motion were validated with the centrifuge tests reported in the literature. Based on numerical studies, an empirical equation is developed for the determination of liquefaction-induced maximum uplift of the underground structure without replacement of the in-situ sand. It is found that the replacement of soil around the structure with 2D width and spacing of D can reduce the maximum uplift by 50%.

• Journal of Wetlands Research
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• v.17 no.1
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• pp.45-52
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• 2015

We obtained the following results from investigation on vegetation damage from 5 to 6 August, 2013, about one year after an accident that hydrofluoric acid leaked from a chemical maker, Hube Globe in Gumi. Pinus densiflora and Pinus strobus showed very severe damage. Ginko biloba, Quercus acutissima, Pinus rigida, Salix glandulosa, Hibiscus syriacus, and Lagerstroemia indica showed severe damage. Quercus variabilis, Lespedeza cyrtobotrya, and Miscanthus sinensis showed moderate damage. Quercus aliena, Smilax china, Arundidinella hirta, Ailanthus altissima, Robinia pseudoacacia, and Paulowinia coreana showed slight damage. We did not find any plants without leaf damage around there. This result means that fluoride damage still persists in this area as was known that fluoride remains for a long time in air, soil and water and exerts negative effects at all levels of an ecosystem. In addition, fluoride content contained in plant leaf depended on the distance from a fertilizer producing factory and vegetation damage tended to proportionate to the concentration in the Yeocheon industrial complex. In these respects, a measure for removal or detoxification of the remaining fluoride is urgently required around the hydrofluoric acid leak spot. Fertilizing of dolomite containing Ca and Mg, which can trap fluoride, was prepared as one of the restoration plans. In addition, phosphate fertilizing was added in order to enhance soil ameliorating effects. Furthermore, we recommend the introduction of tolerant plants as the second measure to mitigate fluoride damage. As the tolerant plants to make a new forest by replacing trees died due to hydrofluoric acid gas damage, we recommended Q. aliena and S. china, A. hirta, etc. were recommended as plant species to add mantle vegetation to the forest margin to ensure stable interior environment of the forest.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.473-480
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• 2006

Liquefaction of soil foundation is one of the major seismic damage types of infrastructures. In this paper, deterministic and probabilistic approaches for the evaluation of liquefaction potential are briefly summarized and the risk assessment method is newly proposed using seismic fragility and seismic hazard curves. Currently the deterministic approach is widely used to evaluate the liquefaction potential in Korea. However, the there are a certain degree of uncertainties in the soil properties such as elastic modulus and resistant capacity, therefore the probabilistic approach is more promising. Two types of probabilistic approach are introduced including (1) failure probability for a given design earthquake and (2) the seismic risk of liquefaction of soil for a given service life. The results from different methods show a similar trend, and the liquefaction potential can be more quantitatively evaluated using risk analysis method.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.845-862
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• 2009

Recently, Tunnel in soil has been designed frequently because Mountain Tunnel has been increased rapidly due to straight of horizontal curve and residents' complaints, tunnel portal has been planned at closed to surface for minimization of environmental damage. To excavate tunnel in soil, where displacement and crushing occur in tunnel face and crown because of unstable ground condition, appropriate reinforcement method needed. On this paper, through design and construction of the soil tunnel, consider application of reinforcement method, economical efficiency and stability.