• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.325-329
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• 2008

This study was conducted to compare the postharvest physiological characteristics of 2 paprika cultivars; 'Special', 'Fiesta' grown in 2 regions: Chuncheon(plain region) and Hwacheon(semi-high land region), and by 2 cultural methods; soil and hydroponic(rock wool culture). Respiratory rate of paprika fruit was higher in soil culture, and ethylene production was higher in Chuncheon region of both cultivars. As the thickness of fruit flesh showed thicker in Hwacheon region and hydroponic culture, the firmness of fruit was in proportion to thickness. Vitamin C content was higher in red-cultivar, 'Special'. and in Chuncheon region. Soluble solids was higher in 'Special', but there was no different between cultural regions. The fruit of both cultivars was grown smaller in Chuncheon region, and the fruit shape of 'Fiesta' progressed faster in soil culture. The surface color of fruit was higher in Hwacheon, and although there was no significantly different between cultural method, both cultivars grown by hydroponics was shown vivid color. As above results, for the long term circulation and high quality of fruit, paprika may be cultivated by hydroponics in high-altitude region.

• Journal of Environmental Science International
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• v.25 no.11
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• pp.1541-1554
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• 2016

To understand the characteristics of vanadium leaching from soils formed by the weathering of basalts, paleo soil at Gosan, Jeju Island, Korea, and several present-day soils from neighboring areas were collected. Leaching experiments were carried out by two approaches: 1) batch experiments under various geochemical conditions (redox potential (Eh) and pH) and 2) continuous leaching experiments under conditions similar to those of natural environments. From the batch experiments, leached vanadium concentrations were highest under alkaline (NaOH) conditions, with a maximum value of $2,870{\mu}g/L$, and were meaningful (maximum value, $114{\mu}g/L$) under oxidizing ($H_2O_2$) conditions, whereas concentrations under other conditions (acidic-HCl, $neutral-NaHCO_3$, and $reducing-Na_2S_2O_3$) were negligible. This indicated that the geochemical conditions, in which soil-water reactions occurred to form groundwater with high vanadium concentrations, were under alkaline-oxidizing conditions. From the continuous leaching experiments, the pH and leached vanadium concentrations of the solution were in the ranges of 5.45~5.58 and $6{\sim}9{\mu}g/L$, respectively, under $CO_2$ supersaturation conditions for the first 15 days, whereas values under $O_2$ aeration conditions after the next 15 days increased to 8.48~8.62 and $9.7{\sim}12.2{\mu}g/L$, respectively. Vanadium concentrations from the latter continuous leaching experiments were similar to the average concentration of groundwater in Jeju Island ($11.2{\mu}g/L$). Furthermore leached vanadium concentrations in continuous leaching experiments were highly correlated with pH and Al, Cr, Fe, Mn and Zn concentrations. The results of this study showed that 1) alkaline-oxidizing conditions of water-rock (soil) interactions were essential to form vanadium-rich groundwater and 2) volcanic soils can be a potential source of vanadium in Jeju Island groundwater.

• Journal of the Korean Geotechnical Society
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• v.36 no.10
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• pp.33-39
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• 2020

A geological repository has been considered as an option for the disposal of high-level radioactive waste (HLW). The HLW is disposed in a host rock at a depth of 500~1,000 meters below the ground surface based on the concept of engineered barrier system (EBS). The EBS is composed of a disposal canister, buffer material, backfill material, and gap-filling material. The compacted bentonite buffer is very important since it can restrain the release of radionuclide and protect the canister from the inflow of ground water. The saturation of the buffer decreases because high temperature in a disposal canister is released into the surrounding buffer material, but saturation of the buffer increases because of the inflow of ground water. The unsaturated properties of the buffer are critical input parameters for the entire safety assessment of the engineered barrier system. In Korea, Gyeongju bentonite can be considered as a candidate buffer material, but there are few test results of the unsaturated properties considering temperature variation. Therefore, this paper conducted experiment of soil-water characteristic curve for the Gyeongju compacted bentonite considering temperature variation under a constant water content condition. The relative error showed approximately 2% between test results and modified van-Genuchten model values.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.535-543
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• 2016

This study has been carried out to evaluate the CBR characteristics and the correlations among every soil properties of National road in Yeongnam region. Total of 480 soil samples were collected from 41 administrative districts for more than 30 years. Their physical and mechanical properties such as natural water content, the Atterberg limit, No. 200 sieve passing, the compaction test and the CBR test results were involved. The soils in Yeongnam region, SM, SC, SP and CL by USCS have predominated approximately 79%. The test results show that average CBR values of gravel and sand range from 12.7% to 20.3% and those of silt and clay range from 4.8% to 7.1%. It means that average CBR values of fine grained soils are less than a half of coarse grained one. Natural water content, No. 200 sieve passing, optimum moisture content and maximum dry density of soils are well correlated with CBR values. Especially, it presents that No. 200 sieve passing is the best correlation factor with CBR value. If consider the partition off this region into 6 zones of classified by mother rock, the correlation between CBR value and every soil properties tends to increase. It is suggested that tables, figures and the regressions described in this paper may be available for designers and engineers to understand the characteristics of an embankment materials in Yeongnam region.

• The Journal of Engineering Geology
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• v.24 no.4
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• pp.535-550
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• 2014

The origins and varieties of natural radioactive materials, including uranium and radon-222, were examined in a drilled borehole extending to a depth of 120 m below the surface in the Goesan area. In addition to core samples, eight groundwater samples were collected at different depths, using a double packer system and bailer, and their geochemical characteristics were determined. Most of the rock samples from the drilled core consisted of granite porphyry, with sedimentary rocks (slate, carbonate, or lime-silicates) and pegmatite occurring in certain sections. The pH of samples varied from 7.8 to 8.4, and the groundwater was of a Na-$HCO_3$type. Uranium and thorium concentrations in the core were < 0.2-14.8 ppm and 0.56-45.0 ppm, respectively. Observations by microscope and an electron probe microanalyzer (EPMA) showed that the mineral containing the natural radioactive materials was monazite contained in biotite crystals. The uranium, which substituted for major elements in the monazite, appeared to have dissolved and been released into the groundwater in a shear zone. Concentrations of Radon-222 in the borehole showed no close relationship with levels of uranium. The isotopes of noble gases, such as helium and neon, would be useful for analyzing the origins and characteristics of the natural radioactive materials.

• Economic and Environmental Geology
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• v.41 no.2
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• pp.183-199
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• 2008

This study is focused on characterization of the physio-chemical and mineralogical properties, investigation of their vertical changes in the tailing profile of the Guryoung mining area, classification of the profile into distinct zones, and condition conceptual model of physio-chemical conditions and phases-water relationships controlling the element behaviors in the tailings. The upper part of the groundwater is characterized by the high contents of $Fe_2O_3$ and $SO_3$ for whole rock analysis, low pH, and the occurrence of jarosite, schwertmannite and Fe-oxyhydroxide as the secondary mineral phases. The tailing profile can be divided into the covering soil, jarosite zone, Fe-sulfate zone, Fe-oxyhydroxide and gypsum-bearing pyrite zone, calcite-bearing pyrite zone, soil zone, and weathered zone on the based of the geochemical and mineralogical characteristics. The profile can be sampled into the oxidized zone and the carbonate-rich primary zone with the dramatic changes in pH and the secondary mineral phases. The conceptual model proposed for the tailing profile can be summarized that the oxidation of pyrite is the most important reaction controlling the changes in pH, the dissolution of the primary silicates and carbonates, the precipitation of secondary mineral phases, acid-neutralizing, and heavy metal behaviors through the profile.

• Journal of Korean Society of Forest Science
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• v.77 no.3
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• pp.276-282
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• 1988

Many landslides occurred at the western part of Gyeongnam province by the typhoon No. 875. Their conditions and causes were investigated and were summarized as follows : The total number of landslide occurred was 2,490 and its area was 156.53ha. In about 94% of landslides and about 97% of landslides area occurred in 3 counties, Sancheong, Hamyang and Geochang. The landslides smaller than 0.01ha was 49% of the total indicating that about half of them were the small landslides. Considering homogenous topography amount of precipitation and forest type landslides appeared to be mainly has a high affected by the geological factor because the landslides mainly occurred in the deep weathered soil of igneous rock. The landslides occured on concave slopes of 31 to $35^{\circ}$ in steepness with low crown density. In the area of the deep weathered soil, landslide likely occur repeatedly. Therefore, regular erosion control works are recommended in the area of pos for disaster prevention and counter-measures.

• Journal of the Mineralogical Society of Korea
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• v.23 no.4
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• pp.347-356
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• 2010

Bauxite is a main raw material for the production of alumina and aluminum hydroxide in the processing plant of KC company. It is a NORM (Naturally Occurring Radioactive Materials), and its waste, red mud, is a TENORM (Technologically Enhanced Naturally Occurring Radioactive Materials). The purpose of the geochemical and mineralogical investigations of the bedrock and soils in and around the plant, a large NORM source, was to provide basic data for measuring the radiation dose and protecting from radioactive hazards. Soils were mixtures of minerals derived from the country rock (quartz, feldspar, mica, kaolin, gibbsite, and sepiolite) and bauxite (hematite, boehmite, and calcite) of open-air storage. Average U and Th contents of the soil samples were 4.7 ppm and 23 ppm, respectively, indicating somewhat Th anomaly. The average concentrations of radionuclides are $^{40}K$ 100~1,433 Bq/kg, $^{226}Ra$ anomaly in the red mud open-air storage. Soil external hazard indices range from 0.10 to 1.66 with an average of 0.63. Although most of the indices are below 1.0 that is a regulation value, those of 4 samples of total 41 soil samples exceed 1.0, requiring further detailed investigation.

• Journal of the Korean Institute of Landscape Architecture
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• v.17 no.3
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• pp.21-34
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• 1990

Trail and campground deteriorations and their environmental changes of soil and vegetation were studied in Tonghwa -Sa district of Mt. Palgong Natural Park through 1988 into 1989. The results are summarized as follows : 1. The bare width of trail as one of the trail condition factor was significantly greater on the more heavily used trail. Deterioration types of trail which had higher frequency for a total of 45 observations were rock exposure(42%), trail deepening(40%) and root exposure(18%) in the high order. And also sound type on which the trail was not deteriorated at all amounted to 33% of all observations. 2. Ecological changes of soil and vegatation of trailsides were not found at a uniform tendency except that soil hardness was slightly decreased from trail edge to the forest, but they could be grouped by the type of user\`s behavior and site conditions. Use impacts on the natural environment of trailside in Mt. Palgong are still far from the severe harmulness. 3. Worse damages to compground condition were appeared in Bawi-gol than Susu-gol campsite. Types of mechanically damaged trees were tree with exposed root(63% ), scared tree(43% ), mutilated tree(30 % ) and felled tree in highly frequent order. And diameter increments of trees in campsites were oppressed by the campers. 4. Tree damage types and their frequencies could be basic as a means of which grasp the bounds of user's impacts. User's disturbance on campsite extended to the distance of 70∼90m from the core of campsite at Pawi-gol and 20∼30m at Susu-gol respectively. As the tolerant trees to use impact, Lespedeza maximowiczii, Rhus trichocarpa, Acer palmatum, Rubus crataegifolius and Celastrus orbiculatus were considered.

• Journal of the Korean Geotechnical Society
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• v.35 no.8
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• pp.17-30
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• 2019

Based on pile load test results for various pile types that were constructed in-situ and pile design data of prebored PHC piles, the ratio of skin friction to total capacity (SRF) was analyzed. A SRF distribution range from the pile load test results for pilot test prebored PHC piles was 42~99% regardless of relative penetration lengths, soil types, and pile load test types. However, a SRF distribution range from the pile design data for prebored PHC piles was 20~53% regardless of relative penetration lengths and pile diameters. Also, a SRF distribution range from the restrike dynamic pile load test results for pretest working prebored PHC piles was a scattered range of 4~83% regardless of pile diameters, relative penetration lengths and soil types. The scattered SRF of pretest working piles was caused to the quality control issue on the filling of cement milk around piles and this quality control issue should be improved. The average SRF calculated by the current design method was estimated to be 2.2 times lower than the average SRF of the pilot test piles. It is because skin friction resistance is calculated at a very low level. Therefore, a new design method for skin friction will be proposed based on this study.