• Journal of computational fluids engineering
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• v.18 no.3
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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.

• Korean Journal of Environmental Agriculture
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• v.3 no.2
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• pp.23-29
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• 1984

Agricultural soil samples collected from 121 sites (plastic film house 59, up-land 30 and orchard 32 sites) were evaluated by steam distillation and GLC-ECD analysis for organochlorine pesticides (${\gamma}-BHC$, heptachlor, p,p'-DDE, dieldrin, p,p'-DDD, and p,p'-DDT) in Jeollanam-Do area. Total residues of organochlorine pesticide in orchard, plastic film house and up-land were 0.415, 0.234 and 0.156ppm, respectively. Ninety-four percent of total residue was p,p'-DDT and its homologues (p,p'-DDE and p,p'-DDD). ${\gamma}-BHC$ was detected in all soil samples at $trace{\sim}0.050ppm$ range. Residue levels of organochlorine pesticide increased in the order of p,p'-DDE, ${\gamma}-BHC$, heptachlor, dieldrin, p,p'-DDT and p,p'-DDD.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.1
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• pp.72-76
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• 1998

In order to investigate the emission pattern of sulphur dioxide gas from the soils in the plastic film house, the amounts of sulphur dioxide gas emitted from soils was periodically measured either in the plastic film house condition or in the incubator where the interior temperature was controlled to 10, 20. 30 and $40^{\circ}C$. Each soil was mixed with either mushroom, poultry, pig or fish meal compost at the rate of 0, 10, 20, 30, 40 and 50g/kg for individual treatment and then treated with addition of 50, 100, 150 and 200ml of water. A significant increase in the emission of sulphur dioxide gas was observed in the treatment of fish meal compost and such increase was initiated from the rate of l0g/kg, while little difference was observed in other treatments. Compared to upland soils, as control, the horticultural soils containing higher sulphur content emitted more sulphur dioxide. The emission of sulphur dioxide was favoured as temperature increased and was highest with the addition of 150ml of water.

• Solar Energy
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• v.6 no.2
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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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• 2005.07b
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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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• v.15 no.1
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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.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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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.

• Journal of the Korean Vacuum Society
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• v.13 no.1
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• pp.29-33
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• 2004

In this paper, we investigated the ultra-low temperature(<$150^{\circ}C$) polycrystalline silicon film on plastic substrate application using RF-magnetron sputtering and excimer laser annealing. Amorphous silicon films were deposited using Ar/He mixture gas at $120^{\circ}C$ and in-film argon concentration was less than 2%, which was measured to Rutherford Backscattering Spectrometry. At energy density 320mJ/$\textrm{cm}^2$, RMS roughness was 267$\AA$ and UV crystallinity was 62%. The grain size varies from 50nm to 100nm after excimer laser irradiation.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.3
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• pp.363-369
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• 2011

In this study, a direct pattern forming process on a plastic film using ultrasonic vibration energy is investigated. A tool horn containing micro-patterns is attached to an ultrasonic power supply, and is used to press a plastic film with ultrasonic vibration in order to replicate micro-patterns on the surface of the plastic film. To replicate micro-patterns with high accuracy, the tool horn should be designed to allow only the longitudinal vibration, not the transverse vibration. For this purpose, the design of a tool horn is investigated through finite element analysis, from which the resulting natural frequency of the tool horn can be adjusted in the range of the ultrasonic power supply. The analysis result is then reflected on the optimal design and fabrication of the tool horn. The validity of the developed tool horn is discussed through pattern-forming experiments using the ultrasonic vibration of the developed tool horn.

• Journal of Surface Science and Engineering
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• v.29 no.5
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• pp.379-385
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• 1996

Adhesion of Cu/Cr and Cu/$Cu_xCr_{1-x}$ thin films onto polyimide substrates has been studied. For an adhesion layer, Cr or Cu-Cr alloy films were deposited onto polyimide using DC magnetron sputtering machine. Then Cu was sputter-deposited and finally, Cu was electroplated. Adhesion was evaluated using $90^{\circ}C$ peel test or T-peel test. Plastic deformation of the peeled metal layer was qualitatively measured using XRD technique. It is confirmed that high interfacial fracture energy and large plastic deformation are important to enhance the peel adhesion strength. High peel strength is obtained when the interface is strongly bonded. More ductile film has higher peel strength. In Cu-Cr alloy films, opposite effects of the Cr addition in the alloy film on the peel strength are operative: a beneficial effect of strong interfacial bonding and a negative effect of smaller plastic deformation.