• Journal of the Korean GEO-environmental Society
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• v.9 no.5
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• pp.37-43
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• 2008

Inorganic injection material, which is one of the ground improvement materials, consists of cement accelerator and inorganic micro particle. The inorganic injection material is known to overcome the major limitations of water glass type improvement materials, which are leaching and accompanying strength loss. The inorganic injection material is superior in durability and strength, and environmentally friendly since leaching is prevented. In this study, the effectiveness and environment-friendliness of the MIS(Micro Injection-process System) using the inorganic injection material is compared to SGR, which uses the water glass. The performed tests were unconfined compression test, chemical resistance test, and fish poison test. The unconfined compression tests showed that the MIS results in 1.7 times higher 28 day strength compared to the SGR. In addition, the strength continually increased with time for the MIS, while it decreased for the SGR. The chemical resistance tests indicated that the rate of change in length using the MIS is 10~25 times smaller than when using the SGR. The fish poison test proved that MIS was more environmentally friendly. The analysis of chemical ingredients of leached showed that the amount of $Cr^{6+}$, Pb and Si leached from the MIS is less compared to the SGR. Accordingly, the MIS grout is more high-strength than existing SGR grout. It is excellent in shortening of construction period, structural stability of foundation and environmentally friendly. So, it is considered that it has not little the problem about groundwater pollution.

• Journal of the Korea Concrete Institute
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• v.20 no.3
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• pp.283-290
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• 2008

The repair technique using surface impregnation of reactive compound is so effective for deteriorated concrete structures that many researches are recently focused on these works. Particularly, inorganic impregnant is regarded as ecofriendly material because there is no air-pollution during manufacturing process as well as field coating works. Furthermore, The delamination between old concrete and impregnated surface does not occur, resulting from different material characteristics. In order to evaluate the durability performance of surface-impregnated concrete, durability evaluation through the long-term exposure tests is significant, however, experiments are usually limited to the temporary and qualitative laboratorial scope. In this study, durability characteristics for inorganic and organic/inorganic impregnated concrete specimens are evaluated through longterm chloride exposure test. The specimens with 21MPa and 34MPa strength have been prepared and exposed to chloride attack in the atmospheric, tidal, and submerged conditions. Evaluation for compressive strength, chloride penetration, and electrical potential (half cell potential) for steel corrosion are performed for the specimens exposed for 2 years. From the results, no distinct strength gaining is observed but the resistance to chloride penetration and steel corrosion is evaluated to be improved through surface impregnation. The more improved resistance to chloride attack is measured in the inorganic impregnated concrete and the results from atmospheric condition show more improved resistance to chloride attack than those from submerged and tidal condition.

• Journal of Korea Soil Environment Society
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• v.1 no.2
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• pp.91-101
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• 1996

In recent years, phytoremediation, the use of plants to detoxify hydrocarbons, has been a promising new area of research, particularly in situ cleanup of large volumes of slightly contaminated soils. There is increasing need for a mathematical model that can be used as a predictive tool prior to actual field implementation of such a relatively new technique. Although a number of models exist for solute-plant interaction in the vegetated zone of soil, most of them have focused on ionic nutrients and some metals. In this study, we developed a mathematical model for simulation of bioremediation of hydrocarbons in soil, associated with plant root systems. The proposed model includes root interactions with soil-water and hydrocarbons in time and space, as well as advective and dispersive transport in unsaturated soil. The developed model considers gas phase diffusion and liquid-gas mass exchanges. For simulation of temporal and spatial changes in root behavior on soil-water and with hydrocarbons, time-specific distribution of root quantity through soil was incorporated into the simulation model. Hydrocarbon absorption and subsequent uptake into roots with water were simulated with empirical equations. In addition, microbial activity in the rhizosphere, a zone of unique interaction between roots and soil microorganisms, was modeled using a biofilm theory. This mathematical model for understanding and predicting fate and transport of compound in plant-aided remediation will assist effective application of plant-aided remediation to field contamination.

• Journal of Conservation Science
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• v.18 s.18
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• pp.19-32
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• 2006

The stone pagoda of the Bunhwangsa temple made by piling small brick-shaped stones. The major rock forming stone bricks are andesites with variable genesis. Rock properties of the pagoda roof stone suffer partly including multiple peel-offs, exfoliation, decomposition like onion peels, cracks forming round lines and falling off stone pieces. The stylobates and tabernacles in all the four directions the pagoda are mostly composed of granitic rocks. Those rock properties are heavily contaminated by lichens and mosses with the often marks of inorganic contamination by secondary hydrates that are dark black or yellowish brown. Within the four tabernacles and northern pagoda body situated to relatively high humidity. There are even light gray precipitate looking like stalactites between the northern and western rocks of the body Their major minerals are calcite, gypsum and clays. The stone lion standing in the southeast and northeast side are alkali granite, while that in the southwest and northwest lithic tuff. Total rock properties of the pagoda are 9,708 pieces, among the all properties, fractured blocks are 11.0%, fall out blocks are 6.7% and covered blocks by precipitates are 7.0%, respectively. The pagoda has highly deteriorated the functions of the rock properties due to physical, chemical and biological weathering, therefore, we suggest that this pagoda has need to do long term monitoring and synthetic conservation researches.

• Journal of Korea Soil Environment Society
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• v.1 no.2
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• pp.51-60
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• 1996

Removal of Mn-EDTA complex and fluoride by use of hematite and ferrite, which are the by-product to be disposed of as industrial wastes, was investigated. For the comparison of removal rate, Na-bentonite known as excellent absorbent of inorganic contaminants was included in the experiments. As the results of batch mode experiments, for manganese, ferrite-A revealed 48∼65% of removal capacity, ferrite-B 46∼57%, hematite 17∼26%, while Na-bentonite showed 10∼23% of removal, depending on the initial concentration. Meanwhile, in case of fluoride : hematite revealed 53 ∼63% of removal : ferrite-A 54∼63 %, while ferrite-B did 20∼38 %. From the results, it can be postulated that the capacity of hematite and ferrite to attenuate inorganic pollutants, especially when they form complex ions, is superior to that of Na-bentonite. Consequently, the mixing of such oxide minerals with Na-bentonite will reinforce the function of Na-bentonite, especially in the undergroud liner aspect.

• Korean Journal of Heritage: History & Science
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• v.45 no.1
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• pp.86-101
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• 2012

The constituting rocks of Multi-storied Round shape stone Pagoda of Unjusa Temple are lithic tuff and rhyolite tuff breaccia which show green or grey and also rock fragment with poor roundness are present in the structure. lithic tuff is composed of feldspar and quartz which are glassy texture and cryptocrystalline and also micro crystalline are scattered. phenocryst quartz and feldspar in the substrate composed of feldspar and opaque minerals are found in rhyolite tuff breaccia. dust, exfoliation, cavity, fracture and crack are observed in all the stone of the pagoda and the result of Infrared Thermography shows partial inter cavities have developed severely which may cause further exfoliation. In addition, a great deal of various grey, green, and yellow brown lichen as well as bryophyte are present at the upper part of eastern and western roof stone located above the third floor. Discolors remarkably shown at stereobate and roof stone are identified as inorganic pollutants such as manganese oxide, iron oxide and iron hydroxide. The stone of the pagoda of the Chemical Index of Alteration (CIA) and the Weathering Potential Index (WPI) are 55.69 and 1.12 respectively and this corresponds to a highly weathered stage. The measured values, average ultrasonic velocity 2,892m/s, coefficient of weathering 0.4k and compressive strength $1,096kg/cm^3$, suggest that the rock strength and durability are weakened.

• Applied Biological Chemistry
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• v.45 no.1
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• pp.1-10
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• 2002

식품과 사료에서 곰팡이독소 오염은 세계적으로 중요한 문제이다. 곰팡이독소는 곰팡이의 이차대사산물로서 인축중독증을 야기하며 경제적인 손실을 초래한다. Aflatoxin, ergot alkaloid, fumonisin, ochratoxin, tremorgenic toxin, trichothecene 및 zearalenone 등이 식품과 사료에서 흘러 발생하는 곰팡이독소이다. 어떤 곰팡이는 하나 이상의 곰팡이독소를 생산하고, 또 어떤 곰팡이독소는 여러 종의 곰팡이에서 생성되기 때문에 여러 곰팡이독소가 함께 발견된다. 곰팡이독소의 발생에 영향을 끼치는 요인으로는 인위적으로 조절할 수 있는 보관과 환경적 조건도 포함된다. 기후와 같은 비본질적인 요인, 진균류의 계통 특이성 및 계통 변이와 같은 본질적인 요인 및 독소발생의 불안정성은 조절하기 어렵다. 곰팡이독소는 한 종의 동물에 있어서의 감수성과 종에 의존하며 인간에게 갖가지의 만성적 또는 급성적인 영향을 미친다. 그러나 반추동물은 곰팡이독소에 저항력을 가지고 있으며, 이는 반추동물의 위에 존재하는 미생물들이 곰팡이독소의 활성을 억제할 수 있기 때문이다. 곰팡이독소 피해의 경제적인 파급효과는 인축의 수명 단축, 축산물 생산감소, 오염된 식량과 사료의 처리 및 곰팡이독소의 문제점 해결을 위한 연구비용 등을 포함한다. 곰팡이독소 피해감소를 위한 국제적인 노력이 계속 진행되고 있지만 최근에 World Trade Organization이 발효되면서 동 식물이 지역간 자유로운 이동으로 곰팡이독소 피해 경감대책뿐만 아니라 피해측정이 어려워지고 있다.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.1
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• pp.51-54
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• 1984

Fermentation waste from beer production was applied to a newly developed upland soil to evaluate the effect of lime added sludge on corn growth. The mineralization of lime added sludge was faster than that of raw sludge without lime treatment in the upland condition. It was accelerated by low C/N ratio and high lime content in the lime added sludge. The plant growth and yields of corn increased as the sludge application rate increased and so was nitrogen and organic matter contents in soil. Ammonium volatilization is considered to be high in the lime added sludge and thus the raw sludge is more promising as an organic sources.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.1
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• pp.1-10
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• 2016

In this paper, an analysis of the inflowing pollution load of the rivers in Hampyeong bay showed the average organic matter pollution loads of BOD, COD, and TOC to be 79.7 kg-BOD/day, 144.06 kg-COD/day, and 93.0 kg-TOC/day, respectively. The inflowing organic matter pollution load was the heaviest in Sonbul dike, followed by Jupo bridge and Yangman complex. With regard to season, the load characteristics were outstanding in July, the rainy period in the summer. The average inflowing pollution loads of nutrients were 20.9 kg-DIN/day, 17.1 kg-DIP/day, 148 kg-TN/day, and 37.4 kg-TP/day A comparison of the inflowing nutrients loads for each river showed the load to be the heaviest in Yangman complex, followed by Baegok bridge and Jupo bridge. In the experiment on the material budgets of Hampyeong bridge conducted using a box model, the detention time of fresh water was found to be 52.4 days, with the bay displaying the characteristics of a so dissolved inorganic nitrogen (DIN) in the nutrients material budgets, ${\Delta}DIN$ values were found to be negative, indicating the tendency of consumption and open sea leak by photosynthesis to be higher than the nitrogen that flowed in. As for dissolved inorganic phosphorus (DIP), ${\Delta}DIP$ showed positive values, indicating a tendency for accumulation as the supply through organic matter decomposition, elution load of sediments, and inflowing load of the river turned out to be higher than the consumption by phytoplankton and outflow to open sea.

• The Korean Journal of Malacology
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• v.30 no.2
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• pp.117-126
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• 2014

To assess the effect of environmental factors on the sustainability of cultured production manila clam (Ruditapes philippinarum), we investigated the habitat characteristics of tidal flat (Hwangdo and Jeongsanpo in Taean). We measured the physiochemical parameters (temperature, salanity, pH, dissolved oxygen and nutrients) and the characteristics (mean size, chemical oxygen demand, ignition loss, C/N ratio and C/S ratio) of surface sediments. The C/N ratio of Hwangdo and Jeongsanpo were 9.0, 5.3 and the C/S ratio was 0.162, 0.159. The concentration of chlorophyll a at Hwangdo was higher than that of Jeongsanpo and species of micro algae were 102 and 100. The enrichment factor (Ef) and index of accumulation rate (Igeo) of the metals showed that those research areas can be classified as heavily polluted, heavily to moderately polluted, or more or less unpolluted, respectively. So two survey area of cultured clams in the tidal flat have been effected by the various environmental conditions, there are needed an improvement methods and continuous research for increasing the production of manila clam (Ruditapes philippinarum).