• Journal of Soil and Groundwater Environment
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• v.8 no.1
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• pp.57-67
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• 2003

Nitrate contamination by human activities is a serious problem to water-supply in agricultural area. Shallow groundwater is the main source of water-supply, but it is very sensitive to contamination. Study area for nitrate contamination is a region of Iljuk, Kyunggi where is an agricultural area having many livestock facilities in various scales. As a result, the points having availability of incoming of external contaminant are 77%, and the ones over the Drinking Water Limit (DWL) are 32～42%. For a nitrogen isotope analysis, all the points having availability of incoming of external contaminant have $\delta$$^{15}$ N-NO$_3$ values over 5$\textperthousand$, and the points of 59% are strongly affected by nitrogen originated from animal wastes. The major source of nitrate in this area is intensive livestock facilities. Even though a livestock facility had enclosed, it affects groundwater quality for a long time. The chemical property of contaminant source is various according to animal species in surface water, but not in groundwater since some solutes are removed by reactions during an inflow to subsurface.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.158-164
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• 2019

The purpose of this study was to compare the bond strength of resin-modified glass ionomer (RMGI) to dentin with saliva contamination at different stages and using different decontamination procedures. Extracted human permanent molars were embedded onto acrylic resin with the dentin surface exposed. Group I was a control group that was conditioned with polyacrylic acid (PAA). Groups II and III were contaminated with saliva before PAA conditioning and Groups IV, V, and VI were contaminated with saliva after PAA conditioning. After saliva contamination, Groups II and IV were dried, Groups III and V were rinsed and dried, and Group VI was additionally conditioned with PAA. After surface treatment, the dentin specimens were filled with RMGI. Group I showed significantly higher bond strength than the other groups. Group VI showed a significantly higher bond strength than the other saliva contaminated groups. However, there were no significant differences in the failure mode between the different groups. Saliva contamination impaired the bond strength of RMGI to dentin, regardless of when the saliva contamination occurred. Decontamination with washing and drying could not improve the shear bond strength of RMGIC. When saliva contamination occurred after PAA conditioning, additional PAA conditioning improved the shear bond strength.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.865-870
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• 2000

The flow and the moisture contamination of the dry room in the manufacturing process of lithium ion battery are analyzed numerically by finite volume method. Standard ${\kappa}-{\varepsilon}$ turbulent model widely applied in predicting turbulent flow is adopted in this study. Moisture contamination and distribution are studied by assumption of two cases; one-point generation and uniform generation throughout the room. To evaluate ventilation efficiency on moisture contamination, scales of ventilation efficiency are introduced. From these analyses, moisture contamination is strongly dependent on the flow field and the radius of moisture contamination can be reduced by closing a part of outlets in a dry room.

• Journal of Korea Soil Environment Society
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• v.2 no.3
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• pp.31-38
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• 1997

Temporal and spatial comparisons of acid mine drainage contaminated waters are difficult because of the complex physico-chemical nature of the pollutant. In the present study, an acid mine drainage index has been developed and evaluated for the assessment of surface waters. AMD index is calculated using a modified arithmetic weighted index using seven parameters which are most indicative of AMD contamination, i. e. pH value, sulphate, iron, zinc, aluminum, copper and manganese. Weighting is used to express the relative indicator value of each parameter. The proposed AMD index is used to quantify contamination from acid mine drainage over ten different old mine sites and assess the degree of impact on surface on surface waters. As a result of AMD evaluation, the Sukbong Mine located near the Moonkyung province showed lowest AMD value indicating the worst acid mine drainage quality. In overall, Youngdong mine sites showed higher contaimination compared to the other mine sites including Youngsuh, Choongbu, Suhbu and Nambu area.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.3
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• pp.195-206
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• 2014

In this study, soil contamination maps related to Cu and Pb were created at the Busan abandoned mine in Korea using a handheld X-Ray Fluorescence(XRF) and Geographic Information Systems(GIS). Hydrological analysis was performed using the Digital Elevation Model(DEM) of the study area to identify the flow directions of surface runoff where pollutants can be dispersed from the soil contamination sources. 24 locations for measuring the soil contamination related to Cu and Pb were selected by considering the result of hydrological analysis. The results measured at the 24 locations using the handheld XRF showed that the highest value of Cu contamination is 8,255ppm and that of Pb is 2,146ppm. The field investigation data were entered into ArcGIS software, and then soil contamination maps regarding Cu and Pb with a 5m grid-spacing were created after performing spatial interpolations using the ordinary kriging method. As a result, we could know that high concentrations of Cu and Pb are presented at the waste and tailings dumps around the abandoned mine openings. This study also showed that the handheld XRF and GIS can be utilized to create soil contamination maps related to Cu and Pb in the field.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.3
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• pp.159-165
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• 2005

The characterization of radiological contamination inside pipes generated during the decommission of a nuclear facility is necessary before pipes can be recycled or disposed. But, existing direct measurements of radioactive contamination level using the survey-meter can not estimate the characteristic of contamination on a local area such as the pipe inside. Moreover, the measurement of surface contamination level using the indirect methods has many problems of an application because of the difficulty of collecting sample and contamination possibility of a worker when collecting sample. In this work, plastic scintillator was simulated by using Monte Carlo simulation method for detection of beta radiation emitted from internal surfaces of small diameter pipe. Simulation results predicted the optimum thickness and geometry of plastic scintillator at which energy absorption for beta radiation was maximized. In addition, the problem of scintillator processing and transferring the detector into the pipe inside was considered when fabricating the plastic detector on the basis of simulation results. The characteristic of detector fabricated was also estimated. As a result, it was confirmed that detector capability was suitable for the measurement of contamination level. Also, the development of a detector for estimating the radiological characteristic of contamination on a local area such as the pipe inside was proven to be feasible.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.11-15
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• 2006

Attempts were made to increase an efficiency of soil contamination investigation systems (SCISs) including Soil Network and Special Soil Contamination Management Facility Sites in Korea. In order to increase low efficiencies resulting from inappropriate SCISs, possible policy suggestions are driven based on the results from problem findings of Korean policy and comparisons of policies on industrialized countries including United States, United Kingdom, Germany, the Netherlands and Japan. First, functions of Soil Environment Conservation Act (SECA) on liability should be updated and reinforced to initiate a soil contamination investigation process for stakeholders including an owner(s) or a responsible party(ies) of the potentially soil contamination sites positively. Second, appropriate SCISs should be emerged for implementing the Soil Network and Special Soil Contamination Management Facility Sites properly. Stakeholders for the potentially contaminated sites should easily access and raise the soil contamination issues, and soil contamination investigation implemented by liable and profit environment (consulting) companies should be encouraged. Third, the soil contamination reporting system of SECA needs to change legally responsible. Further more, public announcement system showing soil quality of a site which exceeds a certain scale would be considerable. Fourth, liable environment (consulting) companies should legally execute Soil Environment Assessment of SECA.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.2
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• pp.161-166
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• 2021

This study was on leaching test(KSLT) of the aggregate for the products to evaluate the characteristics of contaminants and the possibility of contamination arising from the aggregate. On the basis pH, conductivity, turbidity, TN, TP, COD and heavy metal contents in the aggregate increased as the particle size of the aggregate was smaller. The pH appeared to be 9.9~11.4 which is relatively higher than soil, however, heavy metal has investigated within the 1 region's standard value of soil pollution standards. From the leaching test, there is strong indication that the risk of pollution due to elution of pollutants gets higher with the smaller grain size. Especially conductivity and turbidity are the potential water pollution source and recycled aggregates of 10mm or less could be a potential pollution source since it could elute soluble matters and suspended solid, but there is no proper management standard for them. As a result of evaluating water pollution possibility of the aggregate, the pH displayed in items with a very high possibility of contamination, TN and TP did in item with a low possibility of contamination and on the other hand the heavy metals did in item with a very low possibility of contamination.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.4
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• pp.541-546
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• 2012

This study investigates the detection system of oil pollution level using single optical fiber sensor. This study focus on sensing of oil pollution by moisture and iron powder which are representatives of oil pollution factor. In addition, It is placed that the water and iron powder as an oil pollution factor in the oil tank which is the oil circulation in. The oil pollution detection system was measured by the changing of intensity of light and sensing gap. The result of this experimentation not only confirmed the contamination by moisture volume in the oil tank from the section 190ppm to 540ppm, but also monitored the contamination by iron volume from the section 1200ppm to 3500ppm. This study confirmed effectiveness of this detection system using optical fiber sensor. There is expectations of measuring another section by various optical fiber sensor.

• Korean Journal of Oriental Medicine
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• v.12 no.1
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• pp.49-57
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• 2006

Objectives : This study has attempted to establish an organized system for the microbiological quality of raw materials which are important factors in preparing the standard for microbial limits. Methods : This study has first set up microbial contamination limit test. total aerobic microbial count and total fungi count, int accordance with testing method of the Korea Pharmacopeia 8th edition in order to establish an inspection standard for microbial contamination. Results : The microbial contamination of 18 items that are highly prone to contamination by three regions(Seoul, Daejeon, Gyeongsangbuk-do), As a result, Morus alba Linne and Rehmannia glutimosa Liboschitz var. purpurea Makino showed as high contaminated by WHO's Microbial Contamination Limit standard. In case of Yukjin medicine in the Theory of Herb Medicinal Properties, total bacterial contamination rate showed as 17.7%, total fungal contamination rate showed as 41.2% and total aerobic mircobial count and total fungi count on Ephedra sinica Stapf. Pinellia ternate Breitenbach, Evodia officinalis Dode showed as high measured. The microbial conatmination rate materials which make up Yukmijihwanghwan were mostly high therefore the total aerobic microbial count was measured as high in case of Yukmijihwanghwan, the characteristics about microbial contamination strain is to be researched. Conclusions : By combining the basic data and experimental results related to microbial contamination of herb medicine, the most ideal storage standards for herb medicine has been attempted to be presented.