• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1998.06a
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• pp.383-383
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• 1998

• The monthly packaging world
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• s.345
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• pp.71-78
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• 2022

• Journal of the korean society of oceanography
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• v.34 no.1
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• pp.36-42
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• 1999

To assess present status of polychlorinated biphenyls (PCBs) contamination in Kyeonggi Bay, Namyang Bay, and Lake Shihwa, 63 sediment samples were analyzed and applied to equilibrium partitioning approach. Sediment quality criteria (SQC) for exposure to Kanechlor mixture (KC-mix) was calculated as a value of 16 ${\mu}$g/g-organic carbon (OC). Two sites (Sites Kl8 and Kl9) within Incheon North Harbor (INH) with total PCBs concentrations 48 and 38 ${\mu}$g/g-OC, respectively, exceeded SQC, indicating a potential of adverse biological effects. The advantage and disadvantage of equilibrium partitioning approach has been discussed.

• Journal of Korea Foundry Society
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• v.24 no.1
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• pp.3-9
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• 2004

Die casting is "a process in which molten metal is injected at high velocity and pressure into a mold(die) cavity". Casting with smooth surfaces, high dimensional precision, complicated shapes, and reduced weight can be obtained using this process. But this process is susceptible to casting defects such as porosities, scattered chilled layers, hard spots, etc. For preventing casting defects, we developed "low-velocity high pressure die casting technology", "squeeze die casting technology", "heat insulating sleeve lubricant technology", and "direct pouring technology". The "direct pouring technology" is useful for producing molten metal without oxide contamination. It consists of a pumping system which supplies pure molten metal to the die casting machine. By using this technology, we have successfully reduced oxide contamination in castings to 1/20 of that of our previous castings.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3168-3172
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• 2007

As the minimum feature size decreases, control of contamination by nanoparticles is getting more attention in semiconductor process. Cleaning technology which removes nanoparticles is essential to increase yield. A reference wafer on which particles with known size and number are deposited is needed to evaluate the cleaning process. We simulated particle trajectories in the chamber by using FLUENT and designed a particle deposition system which consists of scanning mobility particle sizer (SMPS) and deposition chamber. Charged monodisperse particles are generated using SMPS and deposited on the wafer by electrostatic force. The experimental results agreed with the simulation results well in terms of particle number and deposition area according to particle size, flow rate and deposition voltage.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1832-1834
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• 2004

The degree of contamination on outdoor insulator is one of the most importance factors to determine the pollution level of outdoor insulations, and the sea salt is known as the most dangerous pollutant. As shown through the preceding study, the generation of salt pollutant and the pollution degree of outdoor insulator have a close relation with meteorological conditions, such as wind velocity, rainfall, and so on. So, in this paper, we have made database using the past meteorological data and ESDD(equivalent salt deposit density) and then we predicted the pollution degree in the future after analyzing currently meteorological data of database.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1851-1853
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• 2004

The important consideration in laboratory designing and construction of the artificial pollution testing facilities including 300kV, 1800kVA AC test system, which enable to test and evaluate the UHV dielectric performance of power insulators up to transmission class, has been dealt in this paper. To evaluate the performance characteristics against contamination for various power installation, especially for the insulators and kinds of bushings, brief investigation and an analysis of test objects and related international codes and standards have been conducted. With the special consideration concerning other matters in designing of these testing facilities have been described with the fixed ratings and references.

• The Journal of Information Technology
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• v.8 no.4
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• pp.1-7
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• 2005

Investigations of high frequency current transformer(HF-CT) waveform characteristics of the surface leakage on kaolin polluted EPDM polymer insulators have been performed. This work is part of a program aimed at examining the potential for HF-CT waveform characteristics analysis to provide information about the environment contaminants and environment condition of polymer insulators. The investigation reported examined the HF-CT waveform characteristics at high frequencies. The use of high frequency measurements for on-line applications reduces electrical inference. This work was peformed utilizing HF-CT to monitor of surface polluted discharge. It was found that HF-CT waveform frequency spectrum, magnitude depend on importantly the duration of the surface discharge activity.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1757-1763
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• 2011

In recent years, accordance to industrial development project on railway investment, adverse environmental issues of the investment, such as disputed cases about recycling and usage of Ballast Cleaner excavated soil, have been continuously increasing. It will not only enhance the regulation of soil contamination but take considerable time and cost in future. In this study, we investigated soil contamination and burnability with soil of Chungang Line, Taebaek Line, Chungbuk Line, in order to seize a possibility of recycling Ballast Cleaner excavated soil for the natural materials and substantial heat sources, which are necessary resources for cement manufacturing process. As a result of this study, It is found that Ballast Cleaner excavated soil is satisfied with a standard. The excavated soil contains a lot of cement ingredients and fossil fuel dust incurred from freight transportation, so it is expected to use for ingredients of cement and replacement of heat sources.

• Biomedical Science Letters
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• v.18 no.3
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• pp.324-327
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• 2012

Acanthamoeba is a free-living amoeba that causes human infections, and recently the incidence of amoebic keratitis has increased among contact lens wearers. In order to investigate Acanthamoeba contamination of contact lens storage cases, a short survey was performed on 57 contact lens wearers, and Acanthamoeba was found in one contact lens storage case. To diagnose Acanthamoeba, the 18s small subunit ribosomal DNA (18s rDNA) gene was amplified by polymerase chain reaction (PCR), and subsequently, the isolate was identified as A. lugdunensis. This species was originally isolated from a freshwater pool in France, and was reported recently to be a cause of amoebic keratitis. This observation indicates the need for a large survey to investigate the extent of Acanthamoeba contamination, and suggests that contact lens wearers be aware of the importance of hygiene and of the implications of Acanthamoeba infection.