• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.1
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• pp.141-152
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• 1994

Our experiment investigated the degree of soil contaimination caused by oil leakage. Each soil sample was taken by boring 5, 8m below the test areas, located 5 to 30m from storage tanks at oil stations. According to the results from a series of laboratory tests(both soxhiet extract test and gas chromatograph test), Traces of a light oil were found in all samples except in Dj8, rocky soil and gasoline and petroleum were not detected. We concluded that soil contamination was caused by the corrosion of storage tanks or alternatively by oil overflow caused during the flooding of underground water seeping into the tank during heavy rain fall or the spillage caused by carelessness during lubrication. Old stations without a concrete box enclosing their metal tanks run a greater risk of oil leakage. To research the effect of oil leakage on plant growth and underground water, We examined the results of research conducted overseas. According to these results, when oil leakage occurs, plant growth is repressed and agricultural crops experience low productivity levels. Also, the contamination of underground water can be serious when oil spreads to the aquifer layer. As a result of these problems, to prevent oil leakage and minimize its contaminating effects at oil stations, it is necessary to improve facilities of storage tanks and have the monitoring system of oil leakage.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.11
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• pp.99-104
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• 1993

We analyzed the D.I. water used in wet cleaning process of semiconductor device manufacturing both at the D.I. water plant and at the wafer cleaning bath to detect the impurity source of D.I. water contamination. This shows that the quantity of impurity is related to the resistivity of D.I. water, and we found that the cleanliness of the wafer surface processed in D.I. water bath was affected by the degree of the ionic impurity contamination. So we evaluated the cleaning effect as different method for Fe ion, having the best adsoptivity on wafer surface. Moreover the temperature effect of the D.I. water is investigated in case of anion in order to remove the chemical residue after wet process. In addition to the control of D.I. water resistivity, chemical analysis of impurity control in D.I. water should be included and a suitable cleaning an drinsing method needs to be investigated for a high yielding semiconductor device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.207-210
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• 1998

Surface electrical conduction in insulator is most important factor to assess the insulation performances of outdoor insulating materials. In this paper, contamination performance of the widely used materials for outdoor insulator - porcelain, EPDM, Silicone rubber - were discussed by measuring properties of average leakage current and scintillation discharge pulses under artificial contamination conditions. The artificial contaminations used were deionized distilled water fog, 0.5wt% NaCl salt fog of light pollution and 2wt% NaCl salt fog of medium pollution. The average leakage current was appeared linearly with applied voltage at dry and clean surface condition. The magnitude of leakage current was almost same at different kinds of samples. In case of deionized distilled water fog, the characteristics of leakage current and applied voltage was most different to that in case of dry and clean condition. In case of salt fog pollution condition. The leakage current was increased above critical voltage. The scintillation discharges were also activated at the level the leakage current and scintillation discharges were increased with increasing pollution degree. The resistance to pollution properties of silicone rubber appeared excellent among them.

• Korean System Dynamics Review
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• v.6 no.1
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• pp.125-145
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• 2005

The Sihwaho Project got off to a bad start, which led to a series of mishaps and an imbalance of the whole project. The purpose of this study is to select the case of Sihwaho as a research subject, clean up the contamination caused by the ill planned project, develop suitable measures to stabilize the lake environment, and find the implications of similar development projects. For this, the authorshave conducted three simulations after studying the structural reasons for the failure of the Sihwaho Policy by identifying cause and effect relationships, pre-testing a number of policy measures for the current lake project, and presenting measures for solving the contamination problem at the lake. The simulations have shown us that filling the lake with seawater is inadequate to solve the problem and that we also have to make efforts to reduce the volume of wastes to the lake as well. The authorshave also analyzed the degree of difference between the simulation and survey results for scenario 1, in which we have studied how much seawater can reduce the contamination of the Sihwaho Lake without the effort to reduce the volume of wastes into the lake. The survey showed that most citizens and employees of the Ministry of Environment did not think it would be serious as the simulation results pointed out, and the employees of the Ministry of Environment were more optimistic about the situation than the public.

• Journal of Veterinary Clinics
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• v.26 no.3
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• pp.286-289
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• 2009

Perineal laceration commonly occurs due to dilation of the birth canal at the time of foaling in primiparous mares. A 7-year-old Thoroughbred mare was presented with faecal contamination of the external genitalia. She was having history of constant straining three days after the mare's first foaling. Physical examination revealed the tearing extended from the deep part of vagina through muscles of the perineal body involved rectal floor and anal sphincter. Tentative diagnosed was third-degree perineal laceration therefore one-stage surgical procedure and a modified surgical procedure at three-week intervals was performed. During postoperative care for 3 weeks, soft faces was a key factor in success. After 3 weeks, the patient was recovered to normal condition completely.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.401-406
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• 2000

Spilling of petroleum hydrocarbons such as gasoline, motor oils, and diesel fuel from underground storage tanks (USTs) is a major source of contamination to ground water and soils. In response to the need of developing an effective and economical cleanup technique, this study investigates the effectiveness of using sonication to enhance the soil flushing method. The study involves laboratory testing, and the testing was conducted using a specially designed and fabricated device to determine the effect of sonication on contaminant removal. The sonication was applied at 20 kHz frequency under different power levels. Test soil was Joomoonjin Sand, and diesel fuel was used as a contaminant of soil flushing test. The results of the investigation show that sonication enhanced the contaminant removal from soils significantly, and the degree of enhancement varied with power levels of sonication. Based on the results of the study, it is concluded that the flushing method with sonication has a great potential to become an effective method for removing petroleum hydrocarbons from the contaminated ground.

• Journal of Drive and Control
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• v.9 no.2
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• pp.46-53
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• 2012

This paper explains how eliminating contamination from the manufacturing processes will lead to better product quality and hence the need for reworking, a trouble free commissioning period and greatly improved production efficiency. All of these will reduce costs and energy usage. It will also ensure that the product is delivered to the customer in a condition that will ensure improved reliability and longer life, again reducing both energy and other operating costs. Correctly designing the contamination control measures will achieve and maintain the level of fluid cleanliness that is required by the end user. The filter is critical to cleanliness management and should be selected with the same degree of thought and consideration as for other major components. This paper explains the role that Cleanliness Management plays in the reducing the carbon footprint of systems and processes by making them perform more efficiently for longer periods. It also examines two differing ways of selecting filters to incorporate the features of newer designs, and shows how significant savings in the costs of ownership can be achieved using these approaches.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.115-119
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• 2003

Pollutants from industry, mining, agriculture, and other sources have contaminated sediments in many surface water bodies. Sediment contamination poses a severe threat to human health and environment because many toxic contaminants that are barely detectable in the water body can accumulate in sediment at much higher levels, the purpose of this study was to make convenient sampling method and optimal treatment of sediment for water quality improvement in reservoir or stream based on an evaluation of degree of contamination. Results for analysis of S-reservoir sediments were observed that copper concentration of almost areas were higher than the regulation of soil pollution (50 mg/1) for the riverbed. S-stream sediments were observed that copper, arsenic and TPH concentration of almost areas were exceeded soil pollution concerning levels for factorial areas. We used Remscreen(version. 1.0) program which is contaminated soil recovery program to select optimal treatment method of contaminant sediments. The result was shown in the order of Thermal Calcination > Excavation, Retrieval and Off-site Disposal(comparative less then contaminant) > Low Temperature Thermal Desorption + Solidification/Stabilization.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.187-190
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• 1999

To reduce the maintenance expence, and the possibility of electric outage and accident, accurate measurement should be carried. But the classical method has some problems in the aspect of man power, reliability, and expence. In this paper, we propose a new type apparatus, which could detect the degree of contamination on insulators on outdoor insulation system, such as transmission and distribution line insulator and bushing. The new type apparatus consists of Pelltier module, electrode system, and measuring part. At first leakage current detecting method was considered, then with the fault(oxidation of electrode) of that method we should propose a another method. We carried various test to prove the possiblity and reliability of the propoused apparatus. And we get some useful result with laboratory test.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.595-597
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• 2000

Poymeric insulators using in an heavy contamination area are easily attached to contaminants such as salt and by-products of industrial processes. To understand its effect on contaminants adhered to these insulators, we manufactured slurry mixed by some kaolin and salt as artificial contaminated solution. And then put samples in its slurry, for about one minute. And these samples are dried in natural condition for 6 days. We measured the degree of contaminant, AC leakage current for these contaminated samples.