• 한국전산유체공학회지
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• 제18권3호
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• pp.20-25
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• 2013

In various manufacturing industries, an in-mold decoration (IMD) process for plastic objects is widely utilized because a film forming and an injection molding processes run simultaneously. In the present study, the deformation of polymer film and filling of resin in the IMD process were numerically investigated to evaluate the quality of the plastic object formed by the IMD process, which consists of thermoforming and injection molding processes. To obtain the initial shape of the polymer film during the injection molding process, the deformation of the polymer film in the thermoforming process was pre-formed using the vacuum conditions to attach the film to a cavity. Since the properties and deformation of polymer film are greatly affected by the behavior of polymer resin being injected into a mold cavity, numerical simulations for the injection molding and film forming were performed with one-way coupling method. The results showed that the injected resin could lead to the tearing of the polymer film in local regions near the corners. In order to verify the proposed numerical methodology, the numerical results of the deformation patterns printed on the initial polymer film were compared with the experimental data. The proposed methodology to couple film forming analysis with injection molding analysis can be used to predict the deformation of film in IMD process.

• 한국환경농학회지
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• 제3권2호
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• pp.23-29
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• 1984

수증기증류법(水蒸氣蒸溜法)으로 추출(抽出)하고 GLC-ECD를 사용(使用)하여 전라남도(全羅南道) 경작지(耕作地) 토양시료(土壤試料) 121점(點)(plastic film house 59, 밭 30, 과수원(果樹園) 32점(點)) 중의 6가지 유기염소계(有機鹽素系) 살충제 (${\gamma}-BHC$, heptachlor, dieldrin, p,p'-DDE, p,p'-DDD, p,p'-DDT)의 잔류분(殘留分)을 분석평가(分析評價)하였다. 총평균잔류량(總平均殘留量)은 과수원(果樹園)이 0.415ppm, plastic film house가 0.234ppm, 밭 토양(土壤)이 0.158ppm이었다. 전체(全體) 잔류수준(殘留水準)의 94%를 p,p'-DDT와 그 동족체(同族體)(p,p'-DDE, p,p'-DDD)가 차지했고, ${\gamma}-BHC$는 모든 공시토양(供試土壤)에서 검출(檢出)되었으며 검출범위는 $trace{\sim}0.050ppm$이었다. 총(總) 평균잔류양(平均殘留量)은 $p,p'-DDD>p,p'-DDT>dieldrin{\approx}heptachlor>{\gamma}-BHC{\approx}p,p'-DDE$ 순(順)이었다.

• 한국토양비료학회지
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• 제31권1호
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• pp.72-76
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• 1998

일반토양과 시설재배지 토양을 공시하여 1l 광구병에 토양 600g씩 충진하고 토양 1kg당 양송이퇴비, 계분퇴비, 돈분퇴비, 어분퇴비를 각각 0, 10, 20, 30, 40, 50g상당량을 시용하였다, 온도를 10, 20, 30, $40^{\circ}C$로 조절하고 중류수를 토양 1kg당 50, 100, 200, 300ml 첨가하여 각 처리별 아황산가스 발생량을 조사하여 다음과 같은 결과를 얻었다. 아황산가스 발생량은 황함량이 적은 양송이퇴비, 계분퇴비 및 돈분퇴비에서는 적었으나 황함량이 많은 어분퇴비 처리구에서는 10g/kg처리에서 부터 매우 큰 차이로 증가 되었다. 어분퇴비처리구는 10g이하에서도 시 용량증가에 따라서 아황산가스 발생량이 현저히 증가되었고, 황함량이 적은 일반토양보다 황 함량이 많은 시설재배지 토양에서 가스발생량이 높았다. 아황산가스 발생량은 온도가 높을수록 증가되었으며, 수분 처리별로는 150ml 첨가구에서 가장 많이 발생되었다.

• 태양에너지
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• 제6권2호
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• pp.22-32
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• 1986

This study was carried out to analyze solar radiation in plastic greenhouse which is covered with polyethylene or polyvinyl chrolide film. A computer model for solar radiation analysis in the plastic greenhouse was developed and solar gain factors for E-W and N-S oriented plastic greenhouse in the greenhouse farming area during winter were investigated. Solar gain factors for E-W plastic greenhouse were 60 to 75 percent which were 10 to 15 percent higher than those for N-S plastic greenhouse from November to January. However, the values were apparently decreased in February and reversed in March, showing 3 to 5 percent higher in E-W plastic greenhouse. About 67 to 72 percent of the total solar radiation was attributed to the south-directed wall and roof for the E-W plastic greenhouse and about 30 percent through walls and 60 percent through roofs for the N-S plastic greenhouse.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.995-997
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• 2005

A plastic substrate for flexible display is developed. The gas barrier and optical properties of the substrate is improved through depositing silicon oxide/nitride layer and coating polymer layer on plastic film by sputtering process and wet coating process. Roll to roll processes will guarantee the productivity in the whole production process of the plastic substrate.

• Journal of Biosystems Engineering
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• 제15권1호
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• pp.14-22
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• 1990

For efficient use of solar energy in plastic greenhouse, thermal storage system was developed. The system was constructed with the counter-flow type air-water heat exchanger using a thin polyethylene film as a medium of heat exchange parts. Experiments were carried out to investigate the heat exchange rate, optimum water flow rate, overall heat transfer coefficient, and the effectiveness of the counter-flow type air-water heat exchanger with polyethylene film bags. Mathematical model to predict air temperature leaving heat exchanger was developed. The results obtained in the present study are summarized as follows. 1. Heat exchange rate in the counter-flow type air-water heat exchanger with polyethylene film bags was compared to that of polyethylene film. Heat exchange rate was almost identical at air velocity of 0.5m/s on polyethylene film surface. But, heat exchange rate of heat exchanger with polyethylene film bag was $32{\sim}55KJ/m^2$ hr higher than that of polyethylene film at air velocity of 1.0m/s. 2. Considering the formation of uniform water film and the sufficient heat exchange rate of polyethylene film bags, optimum water flow rate in polyethylene film bags was $3.0{\sim}6.0{\ell}/m^2$ min. 3. The overall heat transfer coefficient of polyethylene film bags was found to be $35.0{\sim}130.0KJ/m^2\;hr\;^{\circ}C$ corresponding to the air velocity ranging 0.5 to 4.0 m/s on polyethylene film surface. And the overall heat transfer coefficient showed almost linearly increasing tendency to the variation of air velocity. 4. Mathematical model to predict air temperature leaving the heat exchanger was developed, resulting in a good agreement between the experimental and predicted values. But, the experimental results were a little lower than predicted. 5. Effectiveness of heat exchanger for the experiment was found to be 0.40~0.81 corresponding to the number of transfer units due to the variation of air velocity ranging 0.6 to 1.7 m/s.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.288-289
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• 2011

Indium Tin Oxide (ITO) is a typical highly Transparent Conductive Oxide (TCO) currently used as a transparent electrode material. Most widely used deposition method is the sputtering process for ITO film deposition because it has a high deposition rate, allows accurate control of the film thickness and easy deposition process and high electrical/optical properties. However, to apply high quality ITO thin film in a flexible microelectronic device using a plastic substrate, conventional DC magnetron sputtering (DMS) processed ITO thin film is not suitable because it needs a high temperature thermal annealing process to obtain high optical transmittance and low resistivity, while the generally plastic substrates has low glass transition temperatures. In the room temperature sputtering process, the electrical property degradation of ITO thin film is caused by negative oxygen ions effect. This high energy negative oxygen ions(about over 100eV) can be critical physical bombardment damages against the formation of the ITO thin film, and this damage does not recover in the room temperature process that does not offer thermal annealing. Hence new ITO deposition process that can provide the high electrical/optical properties of the ITO film at room temperature is needed. To solve these limitations we develop the Magnetic Field Shielded Sputtering (MFSS) system. The MFSS is based on DMS and it has the plasma limiter, which compose the permanent magnet array (Fig.1). During the ITO thin film deposition in the MFSS process, the electrons in the plasma are trapped by the magnetic field at the plasma limiters. The plasma limiter, which has a negative potential in the MFSS process, prevents to the damage by negative oxygen ions bombardment, and increases the heat(-) up effect by the Ar ions in the bulk plasma. Fig. 2. shows the electrical properties of the MFSS ITO thin film and DMS ITO thin film at room temperature. With the increase of the sputtering pressure, the resistivity of DMS ITO increases. On the other hand, the resistivity of the MFSS ITO slightly increases and becomes lower than that of the DMS ITO at all sputtering pressures. The lowest resistivity of the DMS ITO is $1.0{\times}10-3{\Omega}{\cdot}cm$ and that of the MFSS ITO is $4.5{\times}10-4{\Omega}{\cdot}cm$. This resistivity difference is caused by the carrier mobility. The carrier mobility of the MFSS ITO is 40 $cm^2/V{\cdot}s$, which is significantly higher than that of the DMS ITO (10 $cm^2/V{\cdot}s$). The low resistivity and high carrier mobility of the MFSS ITO are due to the magnetic field shielded effect. In addition, although not shown in this paper, the roughness of the MFSS ITO thin film is lower than that of the DMS ITO thin film, and TEM, XRD and XPS analysis of the MFSS ITO show the nano-crystalline structure. As a result, the MFSS process can effectively prevent to the high energy negative oxygen ions bombardment and supply activation energies by accelerating Ar ions in the plasma; therefore, high quality ITO can be deposited at room temperature.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.988-990
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• 2003

A plastic substrate for flexible display is developed. The developed PES film has good resistance to heat, low intrinsic birefringence, and mechanical stability. The gas barrier property in the substrate is improved through depositing organic and inorganic multi layer on plastic film by PVD and CVD process.

• Transactions on Electrical and Electronic Materials
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• 제15권3호
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• pp.136-138
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• 2014

In this study, cholesterol sensors consisting of a mixture of cholesterol oxidase (ChOx) and zinc oxide (ZnO) nanoparticles (NPs) are constructed on plastic substrates and their sensing characteristics are examined in air. The current of the ChOx-ZnO NP film decreases in magnitude as cholesterol molecules are adsorbed on the film, due to the resulting increase in the number of electrons generated by the reaction between the cholesterol and the ChOx. The cholesterol sensor shows a high sensitivity of $1.08{\mu}A/mM$ and a wide detection range from 10 nM to 1 mM.

• 반도체디스플레이기술학회지
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• 제19권2호
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• pp.37-44
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• 2020

In improving laser cutting of optical plastic films for mass production of optoelectronics display units, it is important to understand particle contamination over optical film surface due to fume particle generation and dispersion. This numerical study investigates the effects of downward and upward air flow motions on fume particle dispersion around laser cut line. The simulations employ random particle sampling of up to one million fume particles by probabilistic distributions of particle size, ejection velocity and angle, and fume particle dispersion and surface landing are predicted using Basset-Boussinesq-Oseen model of low Reynolds number flows. The numerical results show that downward air flow scatters fume particles of a certain size range farther away from laser cut line and aggravate surface contamination. However, upward air flow pushes fume particles of this size range back toward laser cut line or sucks them up with rising air motion, thus significantly alleviating surface contamination.