• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.251-254
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• 2001

In this paper, we analysed the properties change of electric wire when the thermal stress was applied to NFR-8 and FR-PVC [600] wire. Measurement is made of the attenuation of a light beam by smoke accumulating with in a closed chamber due to nonflamining pyrolytic decomposition and flaming combustion. Results are expressed in terms of specific optical density which is derived from a geometrical factor and the measured optical density a measurement characteristic of the concentration of smoke. Referenced documents were ASTM E662 standard test method for specific Ds generated by solid materials. The furnace control system shall maintain the required irradiance level under steady-state condition with the chamber door closed of 2.5${\pm}$0.04[w/$\textrm{cm}^2$] for 20 min. According to the results of the smoke density analysis of NFR-8 and FR-PVC the highest decomposition flaming smoke density range of NFR-8 and FR-PVC were 7.2 to 77.5 and 51.1 respectively. Nonflaming smoke density range of NFR-8 and FR-PVC were 100.4 to 112.2 and 126.5 to 398.8. The amount of carbon monoxide generated was found to be much higher in FR-PVC decomposition than in NFR-8 due to incomp1ete combustion of FR-PVC which has high content of carbon in compound.

• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.275-282
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• 2009

The effects of surface treatment method of reinforcing fiber on the bonding strength between carbon fiber reinforced polymer rebar (CFRP rebar) and high strength concrete have been evaluated in this study. The structural PVA fiber is coated with a proprietary hydrophobicoiling agent and crimped type polyolefin based structural synthetic fiber is deformed with a geometrical modification were used for the reinforcing fiber. The compressive tests have been performed to evaluate the strength property of high strength concrete depending on the surface treatment method of fiber. The bonding property between the high strength concrete and the CFRP rebar was evaluated by means of direct bonding test. The test results indicated that the surface treatment method of fiber effect on the bonding behavior of high strength concrete and CFRP rebar. Also, as the development and propagation of splitting cracks were controled by adding fibers into the high strength concrete, the bonding behavior, bond strength and relative bonding strength of CFRP rebar and high strength concrete were significantly improved.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.3
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• pp.34-40
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• 2009

For the preparation of carbon-slurry fuel, the effects of process parameters on the carbon dispersion stability in the liquid fuel have been investigated. The dispersion stability of carbon-slurry fuels could be monitored by measurements of particle size and carbon contents in the different positions, and observation of dispersion states after centrifuging. Through the application of various additives, it was found that NB463S84 based on polyolefin succinimde showed the best dispersion and longest stability life of carbon-slurry fuel. Also, PIBSI (polyisobutenyl succimide) with the similar functional groups to NB463S84 was effectively synthesized and same dispersion stability was verified by application to carbon-slurry fuel. Finally, the possibility of practical use of carbon-slurry fuels was confirmed by application of the mixing conditions obtained from g scale to kg scale preparation.

• Journal of the Korean GEO-environmental Society
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• v.13 no.2
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• pp.67-73
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• 2012

Asphalt pavement waste can be recycled by crushing and heating methods with additional virgin materials and additives. In this study, a new additive using Sasol wax and Polyolefin elastomer was used for improving the quality of the Superior recycled asphalt pavement(SRP). Additive was added into the recycled mixture by 1.5% and 3% of binder content in order to have PG 70-22 and PG 76-22. Both mixtures were tested by Marshall apparatus, indirect strength testing methods, toughness testing methods, moisture susceptibility testing methods and wheel tracking testing methods. Test results met the standards of KS F 2349 and GR F 4005. Through research, it was found that these special recycled mixtures could be applied for the surface and base course of heavy traffic roads or equivalents. About 13,000 tons of the recycled mixture has been applied on Seoul Olympic road to provide new road to Hangang park for Seoul citizens.

• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.95-99
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• 2016

As the survey results of cultivation area, farmhouse, yield and income to clarify the effect of PO Film on Korean melon industry in Seongju region, the covering areas of PE film of Korea, Kyungsangbuk-do and Seongju-gun in 2014 were decreased 91.5%, 94.9% and 95.2% as to 2010. In contrary, the covering areas of PO film of Korea, Kyungsangbuk-do and Seongju-gun in 2014 were increased 342.5%, 500% and 825% as to 2010. The cultivation area and farmhouse in 2015 were decreased 8.8% and 11.9% than those in 2010. The yield and production in 2015 were 38.2% and 25.9% increased han those in 2010. The gross and net income in 2015 were 1.3 and 2.7 times increased than those in 2010. Finally, to change as PO film, the productivity will be increased. And cleaning work and noxious materials discharge will be decreased.

• Journal of Food Hygiene and Safety
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• v.12 no.2
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• pp.132-140
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• 1997

Additives in plastics are capable of migrating from the packaging materials into the foodstuffs, thereby presenting a source of contamination and a potential health risk to the consumer. The migration from packaging materials into foodstuffs is first of all regulated by examining the amounts of global and specific migrated components. Besides, there is worldwide still a need for practical methods for measuring and monitoring migration from polymers, especially for the testing of migration into fatty foodstuffs. Therefore, these studies were undertaken to investigate the safety status of domestic plastic packaging materials with respect to migration. Another objective of this study was to examine the applicability of ethanol as an alternative fatty food simulant substituting for olive oil and n-heptane. The evaporation residues for various dometic plastic samples determined as described in Korean food laws were in the level from 4.3 to 14.5 mg/$\ell$, which were much lower than the limit value of 150 mg/$\ell$. The global migration values into 95 % ethanol showed to be comparable to those into n-heptane, while the olive oil migration values were comparably higher than those into ethanol or n-heptane and moreover they were not reproducible. The kinetic migration begavior of additives in polyolefin samples into 95% ethanol showed a Fickian diffusion process. The results of these studies on global migration and kinetic testings demonstrate that the ethanol could be successfully substitute for the olive oil and n-heptane as an alternative fatty food simulant, at least in contact with polyoefins.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.3
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• pp.73-76
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• 2020

Silver nanowires (AgNWs) intrinsically possess high conductivity, ductility, and network structure percolated in a low density, which have led to many advanced applications of transparent and flexible electronics. Most of these applications require patterning of AgNWs, for which photolithographic and printing-based techniques have been widely used. However, several drawbacks such as high cost and complexity of the process disturb its practical application with patterning AgNWs. Herein, we propose a novel method for the patterning of AgNWs by employing UV-curable adhesive tape with a structure of liner/adhesive layer/polyolefin (PO) film and UV irradiation to simplify the process. First, the UV-curable adhesive tape was attached to AgNWs/polyurethane (PU), and then selectively exposed to UV irradiation by using a photomask. Subsequently, the UV-curable adhesive tape was peeled off and consequently AgNWs were patterned on PU substrate. This facile method is expected to be applicable to the fabrication of a variety of low-cost, shape-deformable transparent and wearable devices.

• Journal of Bio-Environment Control
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• v.5 no.1
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• pp.57-64
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• 1996

To use effectively the solar energy in greenhouse heating, a high performance solar collector should be developed. And then the size of the solar collector and thermal storage tank should be determined through the calculation of heating load. The solar collector must be set in the optimum tilt angle and direction to take daily solar radiation maximally, and the flow rate of heat transfer fluid through the solar collector should be kept in the optimum range. In this research, the performance tests of a capillary tube solar collector were performed to determine the optimum water flow rate and the results summarized as follows. 1. The regressive equations for efficiency estimations of the capillary tube solar collector in the open loop were modeled in the water flow rate of 700-l,000 $\ell$/hr. 2. The optimum water flow rate of the solar collector was estimated by the second order polynomial regression and the maximum efficiency was 80% at the water flow rate of 850 $\ell$/hr. 3. The solar thermal storage system consisted of a capillary tube solar collector and a water storage tank was tested at the water flow rate of 850 $\ell$/hr in the closed loop, and obtained the solar thermal storage efficiency of 55.2%. 4. As the capillary tube solar collector engaged in this experiment was made of non-corrosive polyolefin tubes, its weight was as light as 1/30 of the flat plate solar collector made of copper tubes. Therefore it was considered to be suitable for the greenhouse heating system.

• Food Science and Preservation
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• v.8 no.3
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• pp.246-251
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• 2001

This study was conducted to investigate the change of qualities of peaches by different packing types and humidity during storage period. The weight loss ratios of 'Kulakatawase' and 'Mibaek' by non-packing were about 6.8% and 4.9% for 4 days storage at room temperature, respectively whereas, the peaches by packing with 30㎛ LDPE were less than 1% for 25 days storage at low temperature and high humidity(95 $\pm$3%). The firmness values of the peaches were not decreased during storage at low temperature compared to the firmness values of the peaches during storage at room temperature. Little difference of total acidity and soluble solids of the peaches was during storage at low temperature. The contents of fructose and glucose in peaches were increased slightly after storage for 25 days but that of sucrose was decreased slightly. When peaches were stored at low temperature(0∼2$\^{C}$) and high humidity(95$\pm$ 3%) after packing with 30㎛ LDPE or 25㎛ perforated polyolefin film 'Kurakatawase ' and 'Mibaek' were able to storage for 20 and 25days, respectively.

• The Journal of Advanced Prosthodontics
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• v.9 no.4
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• pp.287-293
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• 2017

PURPOSE. To compare the dimensional accuracy of three impression techniques- a separating foil impression, a custom tray impression, and a stock tray impression. MATERIALS AND METHODS. A machined mandibular complete-arch metal model with special modifications served as a master cast. Three different impression techniques (n = 6 in each group) were performed with addition-cured silicon materials: i) putty-wash technique with a prefabricated metal tray (MET) using putty and regular body, ii) single-phase impression with custom tray (CUS) using regular body material, and iii) two-stage technique with stock metal tray (SEP) using putty with a separating foil and regular body material. All impressions were poured with epoxy resin. Six different distances (four intra-abutment and two inter-abutment distances) were gauged on the metal master model and on the casts with a microscope in combination with calibrated measuring software. The differences of the evaluated distances between the reference and the three test groups were calculated and expressed as mean (${\pm}SD$). Additionally, the 95% confidence intervals were calculated and significant differences between the experimental groups were assumed when confidence intervals did not overlap. RESULTS. Dimensional changes compared to reference values varied between -74.01 and $32.57{\mu}m$ (MET), -78.86 and 30.84 (CUS), and between -92.20 and 30.98 (SEP). For the intra-abutment distances, no significant differences among the experimental groups were detected. CUS showed a significantly higher dimensional accuracy for the inter-abutment distances with -0.02 and -0.08 percentage deviation compared to MET and SEP. CONCLUSION. The separation foil technique is a simple alternative to the custom tray technique for single tooth restorations, while limitations may exist for extended restorations with multiple abutment teeth.