• Fibers and Polymers
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• v.6 no.3
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• pp.200-205
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• 2005

Celite powder surface-modified with cationic surfactant was used to make polyethylene (PE) specialty film that can be contrasted with ordinary film in having high odor storing capacity and long odor lasting period. Mechanical properties of the films were sacrificed as more celite particles were included, whether celite surface was modified or not. The film with CTAS-modified celite showed the best odor storing and lasting properties for five different flavors of odor, three artificial and two natural ones, among the kinds of films developed. Comparisons among the different films are made, together with brief discussion about the reason for differences in odor lasting period and possible application to packaging industry.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05a
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• pp.110-112
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• 2004

Poyethylene films can be modified by radiation grafting of N-vinyl pyrollidone using y-radiation. FTIR spectra were used to confirm the modification of PE films. The modified films were activated by two-step and one step methods for electroless Cu plating. Morphology of metallized films has been investigated. Electroless Cu plating onto the modified films depends mainly on the grafting degree and activation type. The conductivity of the metallized films has been investigated.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1227-1234
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• 1999

Modified atmosphere packaging of peaches(Prunus persica L. Batsch) was investigated to extend their freshness during distribution. Peaches were packaged in the PE film(20LD, 40LD), the PE film modified by addition of 5%(w/w) zeolite(20CK, 40CK), and the PE film containing $Purafil^{\circledR}$ sachet(20LP, 40LP). Quality indexes of peaches during storage at $20^{\circ}C$ were measured in terms of weight loss, soluble solids content, pH, titratable activity, firmness, color and sensory properties. Gas composition and ethylene content In the film bags changed rapidly at the early stage of storage. Within 8 days, weight loss of the unpacked control increased upto ll.8% but those of the packaged remained below 2%. There was no significant difference in soluble solids content and pH in all the treatments. Ethanol content of peaches packed in 40LD was 12.88 mL/kg and acetaldehyde content in 40CK was $160\;{\mu}L/kg$ for 8 days. Peaches packed in 20CK showed a good visual and sensory Quality. The result suggested that active packaging treatment such as 20CK could be used for extending freshness of peaches during transport period at ambient temperature.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1881-1887
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• 2011

In this work the recyclable new polyethylene(PE) and polypropylene(PP), which are thermoplastic, have been investigated as the eco-friendly insulating candidates to replace the cross-linked polyethylene (XLPE). The temperature dependence of conductivities of these materials has been measured and its effects on electric field and space charge distribution in polymeric insulated power cable under temperature gradient have been calculated. It is shown that the sensitivity of conductivity to temperature change has more critical influence to determine the electric field distribution in the power cable than the absolute value of conductivity does and it can be said that the temperature dependence is one of most important factors for the power cable design.

• Journal of Life Science
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• v.10 no.1
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• pp.61-67
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• 2000

An experiment was conducted for extension of shelf-life of cooked squid (Todarodes pacificus) using modified atmosphere packaging. The products were packed in a Ny/PE/LLDPE (0.015/0.045/0.040 mm) laminated film with air, vacuum, CO2 gas, and N2 gas, respectively, and then stored at 5$^{\circ}C$ and 2$0^{\circ}C$. Keeping qualities of the products were investigated by measuring moisture content, H, volatile basic nitrogen (VBN), viable cell count, thiobarbituric acid (TBA) value, peroxide value (POV) and color value. Good qualities of the products stored at 5$^{\circ}C$were maintained at least 9 days, 11 days, more than 35 days and 24 days in air, vacuum, CO2 gas and N2 gas packaging products, respectively. In cases of 2$0^{\circ}C$ storage, however, the shelf-lives of all the products were only one day. The shelf-life extension of the products were observed in CO2 ga>N2 gas>vacuum>air packaging in order.

• Journal of Adhesion and Interface
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• v.3 no.3
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• pp.15-21
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• 2002

The modified polyethylene(m-PE) films were prepared from aqueous dispersions which were synthesized by reacting poly(ethylene-co-methylacrylate) with aqueous KOH and ammonia solution to attach -COOK, $CONH_2$, and COOH as pendent groups in the polyethylene backbones. Thermal, tensile and heat-seal properties were measured to investigate the effect of the pendent groups. Endothermic peaks on DSC curves were affected by the thermal history of the samples and a melting peak was observed at around $86^{\circ}C$ on the second heating curve while three melting peaks were shown on the first heating curve. A minimum value of tensile strength was shown at 70 mole% of COOK based on pendent groups. Tensile modulus increased with increasing the amide content in pendent groups. The m-PE films were heat-sealed at lower temperature than LDPE films and showed a minimum heat seal strength at around 70 mole% COOK content in pendent groups.

• Journal of Adhesion and Interface
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• v.3 no.3
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• pp.7-14
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• 2002

Modified polyethylenes with polar side groups of -COOK, $-CONH_2$, and -COOH were prepared at a dispersion state in water by reacting poly(ethylene-co-methylacrylate) (PEMA) with aqueous solution of KOH and ammonia. Types and their contents of side groups were investigated by infrared spectroscopy, elemental analysis and atomic absorption analysis. Solution viscosity and surface tension were also measured as a function of solid contents. Stability and transparency of the dispersions were greatly affected by the content of COOK in the side groups. The stable dispersion could be prepared at a composition of COOK of 20 mole% at least. The transparency was increased with increasing the COOK contents, but decreased with increasing the amide content at a constant composition of COOK. Solution viscosities increased abruptly at a lower solid content when the COOK contents were increased, implying higher entanglement between the chains in dispersions with higher content of hydrophilic COOK group. The dispersions of higher COOK content revealed lower surface tension values.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.8
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• pp.1553-1560
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• 2016

In this paper, we design a program that controls the execution permissions for the running application in the Windows system environment. It does not allow general users to execute the program converting the specific location information of the execution program, to any of the bit values with the formal structure information in window program. The converted bit value can be returned to the original bit value in the case of an authorized user, so that the original program can be normally performed. By doing so, it can be more safely used in the risk of reverse engineering for Windows executable program. We implemented the control program for the program execution authority we proposed in this paper, and the experiment was performed. At the results of experiments, it was confirmed that the control function to permit execution for the user program was working properly in the Windows environment.

• Food Science and Preservation
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• v.24 no.6
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• pp.727-733
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• 2017

We investigated the effect of PE film thickness on the modified atmosphere packaging (MAP) deastringency of 'Sanggamdungsi' (Diospyros kaki cv.) astringent persimmon at room temperature ($25^{\circ}C$) and low temperature ($-1^{\circ}C$). The fruits were individually packaged with PE film of which the thickness is 60, 80, 100, 115 or $130{\mu}m$ and stored at room or low ($-1^{\circ}C$) temperature. At room temperature, firmness shows the highest value (23.3-26.5) at $100{\mu}m$ thickness. Top flesh browning and decay was monitored at 20 days after storage, and peel blackening and style-end softening was negligible at optimal thickness. Therefore, optimal film thickness of deastringency at room temperature is $80-100{\mu}m$. At this thickness, the astringency was removed after 5 days and the fruits can be distributed until 10 days after the MAP. At low ($-1^{\circ}C$) temperature, firmness was maintained regardless of film thickness. However, the firmness is higher as the film is thicker. Top flesh browning and decay was not occurred even after 90 days after storage. Peel blackening and style-end softening was monitored at 90 days after storage. Off-flavor was monitored at 115 and $130{\mu}m$ thickness. Therefore, optimal film thickness of deastringency at low ($-1^{\circ}C$) temperature is $80-100{\mu}m$. At this thickness, the astringency was removed after 50 days and the fruits can be distributed until 80 days after the MAP.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.655-665
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• 2014

The effect of modified atmosphere packaging (MAP) on kohlrabi (Brassica olerace L. gongulodes group)'s quality and antioxidant molecule during storage was examined to determine the optimal film package for maintaining freshness. To extend shelf life, MAP was tested using PE $50{\mu}m$ and oriented polypropylene (OPP) films with oxygen transmission rate (OTR) at 3,000, 10,000, $15,000mL/m^2/day/atm$. The OPP film packaging with modified oxygen transmission rate showed a delay in a weight loss and extended storage period. The package with OTR 3000 attained the desired gas composition of $O_2$ 3.2-6.7 kPa and $CO_2$ 13.1-19.8 kPa, in storage at room temperature. Kohlrabi stored in this package showed the lowest weight loss and the highest visual quality. Deterioration and off-odor were developed more rapidly in PE $50{\mu}m$ towards the end of the storage at room temperature. However, there are no differences among OTR films in visual quality and off-odor until 60 days at cold storage. Vitamin C content of kohlrabi was reduced rapidly in OTR 15000 with high transmission rate and showed less loss in PE $50{\mu}m$ and OTR 3000 in both room temperatures and cold storage. Results revealed that an OPP film with OTR 3000 extended the shelf life of kohlrabi in storage with maintained quality and vitamin C.