• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 춘계 학술대회
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• pp.70-71
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• 2005

It was an idea to develop a system to remove the contaminated hot particulate to make clean nuclear research facilities to the clear visibility for researcher. In order to clean micron and sub micron size particulates from used PFC solution as a decontamination tool. Since PFC solution is very expensive so it was a high recommendation to develop the some filtration equipment to purify PFC for next decontamination process, in additionally, reduce the secondary waste. However, we developed an easy and economic filter system to purify the PFC solution. The major advantage of the process operates in closed loop under near ambient conditions, thus minimizing the potential for fugitive TRU emissions and reduces the secondary waste. This has very significant safety and cost impacts. Here we proposed the two types PFC filter systems.

• 한국대기환경학회지
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• 제16권6호
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• pp.633-640
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• 2000

The effects of structure modification of the vortex finder on the collection efficiency and pressure drop have been investigated. The pressure drop in a cyclone having the two stage vortex finder is higher than that in a conventional cyclone and increases proportionally with the increase of square of gas inlet velocity in both cases. The pressure drop of both conventional cyclone of friction resistance at the boundary layer. The collection efficiency of fine dust has been enhanced by addition of vortex finder in a conventional cyclone and gas inlet velocity showing maximum dust removal efficiency increase to 17 m/s(1.7 times of saltation velocity). Optimum size of two stage vortex finder has been induced to 13 cm I.D$\times$2.6cm Length from the results of overall dust collection efficiency. Previous models were tested for the simulation of collection efficiency of cyclone having two stage vortex finder and the Dietz model predict the similar value with experimental results of the present study.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2005년도 춘계 학술대회
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• pp.157-162
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• 2005

The wafer's size has been increased up to 300mm according as the devices have been integrated sophisticatedly. For this process to make 300mm-wafer, it is required strict level which removes the particulates on the surface of wafer. Therefore we need new type wet-station which can reduce DI water and chemical in the cleaning process. Moreover, it is very important to control the temperature and the concentration of chemical wet-stat ion. The chemical supply system which is used currently is not only difficult to make a fit mixing rate of chemical in cleaning process, but also it is difficult to make fit quantity and temperature. We propose new chemical supply system, which overcomes the problems via analysis of fluid and thermal transfer on chemical supply system,

• 한국대기환경학회지
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• 제6권2호
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• pp.155-160
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• 1990

During the period from Mar. 1985 to Feb. 1988, airborne particulate matters were collected and size fractionated by the ANdersen high volume air sampler in Seoul. The concentrations of several heavy metals (Pb, Cu, Zn, Fe, Mn) and benzo(a)pyrene were determined to investigate the size distributions and seasonal variations. And with respect to seven components in the total suspended particulate (TSP), the factor analysis was performed for three groups such as the coarse particles (> 2 $\mu$m), fine particles (< $\mu$m) and TSP. As a result of factor analysis by using the varimax method, the chemical components in the TSP were able to characterize with two principal factors. The first factor, F1 was considered to be a factor indicating the contribution of natural sources and the second factor, F2 was a factor indicating the degree of artificial sources. Each components in the TSP was divided into two main groups of components originated from soil and/or road dust and pollutants originated from automobiles and/or human work.

• 설비공학논문집
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• 제7권4호
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• pp.694-702
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• 1995

When a small absorbing particle is exposed to a strong thermal radiation incidence, it moves towards or away from the radiation source due to the nonuniform internal absorption of the radiation. It is called the photophoretic phenomena and governed by the asymmetry factor. An asymmetry factor for the total wavelength range is calculated to estimate the photophoretic phenomena of a particle in a combustor or in the atmosphere and compared to that for a single wavelength. The samples are soot particulates, water droplets, ice particles, silicon particles, $SiO_2$ particles, aluminium oxide particles, whose spectral complex refractive index are available. Although differences between total and monochromatic asymmertry factors are not much for relatively uniform distribution of the spectral refractive index, they are great in general. Therefore the use of the monochromatic factor will considerably deteriorate the accuracy of the calculation of the photophoresis.

• 대한기계학회논문집
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• 제12권6호
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• pp.1438-1449
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• 1988

본 연구에서는 입자유동을 연속유체(continuous fluid)라 간주하는 2유체모델 을 적용하였고(Fig.2 참조), 실제 유동으로 2상난류제트유동, 관유동에 개발된 모델을 적용하여 모델의 타당성을 검토하였다.

• 멤브레인
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• 제8권4호
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• pp.191-202
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• 1998

경유자동차에서 발생하는 입자상물질은 대기오염의 주범으로 인식되어 국내외적으로 이의 규제가 점점 강화되고 있다. 본 고에서는 전 호에 이어 이러한 입자상물질을 제거하기 위하여 가장 보편적으로 사용되는 필터인 세라믹 하니컴 필터에서의 기공 및 필터특성의 조절과 설계에 대하여 언급하였다. 또한 그 외 각종 필터, 즉 세라믹 화이버 캔들 필터, 세라믹 폼 필터, 세라믹 크로스 플로우 필터 그리고 금속 필터 등의 성능 및 제조방법을 정리하였다. 이와같이 후처리장치용 필터로는 수없이 많은 필터들이 개발되어 많은 실증시험을 거치고 있으나 이러한 필터의 본격적인 상용화를 위하여는 재료 측면에서의 보다 많은 연구, 개발이 뒤따라야 할 것으로 판단된다.

• 한국세라믹학회지
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• 제43권11호
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• pp.680-687
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• 2006

An overview is given to optimize the solid state processes toward phase pure and well-crystallized fine particulates of mixed oxides, serving as electroceramic materials in various genres. Elevation of the reactivity and preservation of stoichiometry of the starting mixture are of universal importance. Mechanical activation is versatile for these purposes, particularly when an oxygen atom as a hinge promotes formation of hetero-bridging bonds between dissimilar cationic species prior to calcination. Case studies carried out recently in the author's laboratory are displayed and compared for ferroelectric materials, i.e. $PbMg_{1/3}Nb_{2/3}O_3$ $xPbTiO_3$(PMN-PT), $(1-y)Pb(Zn_xMg{1-x})_{1/3}$ $yNb_{2/3}O_3$ (PZN-PMN), $BaBi_2Ta_2O_9$ (BBT), $Ba(Mg_{1/3}Ta_{2/3})O_3$ (BMT), and ferromagnetics, i.e. M-, Y-, and Z-phases of Ba-hexaferrites.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.372-373
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• 2006

Modern business trends call for miniaturization of electronic systems. One of the major impedances in this miniaturization is the conductive and inductive components in chips and circuit boards. Direct Write Technology can write these soft magnetic materials, thus allowing for further miniaturization of inductor devices. Another obstacle in electronics fabrication is the size limitations of thick screen-printing and the material limitations in ink jet printing. Direct Write Technologies address both of these limitations by providing feature sizes less than 20 microns with a wide range of materials possibilities. A discussion of the application of these nano-particulate materials by Direct Write Technologies will be presented.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1994년도 추계학술발표회 초록집
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• pp.14-16
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• 1994

The development of proton exchange membrane fuel cells(PEMFCs) with high energy efficiencies and high power densities is gaining momentum because their performance characteristics are attractive for terrestrial(power sources for electrical vehicles, stand-by power), space and underwater application[1]. Fuel cells are capable of running on non-petroleum fuels such as methanol, natural gas or hydrogen and also have major impact on improving air quality. They virtually eliminate particulates, NO$_{x}$, SO$_{x}$, and significant reduce hydrocarbons and carbon monoxide. Especially, fuel cell-battery hybrid power sources appear to be well suited to overcome both the so-called battery problem(low energy density) and the fuel cell problem(low power density)[2].[2].