• Applied Biological Chemistry
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• v.20 no.3
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• pp.296-299
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• 1977

The blue, green, and red colored polyethylene film was used as a covering material for house grown pepper production to compare with the white film. Plant height was the tallest in red PE house(78.8 cm) followed by white, blue, and green PE house. The leaf weight was 0.40g in white PE house and 0.39g in red PE house which was higher than the weight in blue and green PE house. Fruiting percentage was 48.0% and 46.1% in white and red PE house, respectively, however no fruit was set in blue and green PE house. The fruit weight was 3.32g and 2.81g, in red and white PE house, respectively. The K, Ca, Mg, and Fe content in the leaf was the lowest in plants grown in white PE house. The content of K, Ca, Mg, and Fe was the highest in plants grown in green PE house.

• The Korean Journal of Food And Nutrition
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• v.21 no.2
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• pp.165-175
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• 2008

Pacific saury, Cololabis saira kwamaegi, is a traditional local food of the Eastern sea area centering around Pohang. It is well-recognized as being both tasty and nutritious. Nevertheless, bacterial contamination, excessive dryness, and compositional changes have made it edible only during the winter months. Therefore, to improve its storage, this study examined the effects of storage material, type, temperature, and duration on compositional changes in kwamaegi. The studied samples were kwamaegis that had been dried naturally for 15 days. The storage materials included an A-film, a self-developed multi-film made of polyethylene, polyamide, EVOH, and polyethylene; as well as a B-film made of polyethylene, nylon, polyethylene, nylon and polyethylene. The B films were used after pressing and laminating. The storage types included one whole fish(1G), or 2 divided fish(2G), to increase eating convenience. The 2G type was the muscle portion divided vertically after discarding the jowl, skin, and internal organs. The storage temperatures were $0^{\circ}C$, $-15^{\circ}C$, and $-30^{\circ}C$, and the storage durations were 2, 4, and 6 months. Pathogenic bacteria and rheology were measured to observe general compositional changes. The whole kwamaegi showed a total cell number of $1,565{\pm}112$ CFU/100 g flesh, while the divided Kwamaegi showed significantly greater bacterial numbers at $2,031{\pm}145$ CFU/100 g flesh. Psychrophils and halophils increased significantly while coliform were not found; the number of mesophils also increased, but not significantly. There were no significant cell number variations between the A-film and B-film. At $0^{\circ}C$, both the A-and B-films resulted in cell numbers of $115{\sim}212$ CFU/100 g flesh, revealing just $7.3{\sim}10.4%$ of the initial storage levels. Overall, there were no significant differences between the storage materials. Generally, as the storage temperature and duration increased, the moisture content of the kwamaegi decreased. Also, as storage duration and temperature increased, crude protein and crude lipid contents increased; in addition, they increased proportionally as the moisture content of the fish decreased. There were no significant differences in crude ash content with respect to the storage materials, storage temperatures, or storage durations. Finally, there were no significant differences between the kwamaegi samples naturally dried for 15 days and those stored in the B-film vacuum storage for 6 months for strength, hardness, cohesiveness, springiness, gumminess, and water activity.

• Food Science and Preservation
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• v.20 no.3
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• pp.317-322
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• 2013

This study was conducted to investigate the effects of pretreatment and different packaging methods on the physicochemical properties of cold vacuum-dried peaches. All the dried peach samples were stored such as $N_2$ gas substitution, vacuum and passive packaged with polyethylene (PE) film and oriented polypropylene (OPP)/aluminum (Al)/PE film at $40^{\circ}C$ for 50 days. The weight change, pH, soluble solids content, titratable acidity, soluble solid-acid ratio (SS/TA), delta E, browning degree and phenolic compounds were analyzed. The weight change and pH were lower in the 0.1% vitamin C-treated group and were significantly lowest in the vacuum-treated OPP/AL/PE. The soluble solids content and the SS/TA were higher in the non-treated groups than in the vitamin C-treated groups. According to the packaging methods, the $L^*$ values were higher in the vacuum, $N_2$ gas and passive package, in that order. In addition, the browning degree and the delta E value were lower in the pretreated groups and significantly lowest in the vacuum-treated OPP/AL/PE with 0.1% vitamin C group. The phenolic compounds were high for the pretreated groups, according to the packaging methods (vacuum > $N_2$ gas> passive), and the OPP/AL/PE was significantly higher than the PE. These results suggest that different packaging materials and pretreatment methods affected the quality of the dried peaches, and the vacuum-OPP/AL/PE film packaging group showed a high quality.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1021-1030
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• 1996

The mechanism of the mulch film cutter assembly designed as an integral part of a rice transplanting device was developed for mulching cultivation of early season culture rice. This mulch film cutter assembly was directly attached to the transplanting device of the rotary type Japanese transplanter. The principle is that the knife cut a planting slit on the polyethylene film while the planting finger immediately plants seedling into the soil through the planting slit. Computer results implied that the knife of the mulch film cutter assembly can make appropriate planting slit on the polyethylene film as the planting finger effectively plants the seedlings into the paddy soil through the same planting slits.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.375-380
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• 2016

The use of polyethylene film has a problem such as increasing rural environmental contamination, collection costs and farmers' workload. The objective of this study was to evaluate bio-degradable films in terms of yield of maize and soil environment. Treatments were bio-degradable film A (BDF A), bio-degradable film B (BDF B), high density polyethylene (HDPE), and non-mulched (NM) soil. Daily mean values of soil temperature (10 cm depth) under BDF A, BDF B, and HDPE were higher than in NM soil by 2.2, 2.8, $3.1^{\circ}C$ respectively. In the mulching cultivation of maize, bio-degradable film began to degrade from 50~60days after the planting. The degradation was much progressed in the harvest time and almost decomposed in the following spring. The weight of ear of maize was not shown significantly by mulching treatments. There were little changes of soil chemical properties for the bio-degradable film mulching. After using bio-degradable films, the contents of biomass-C and dehydrogenase activity increased from 92 to $137{\sim}147mg\;kg^{-1}$, and from 87 to $123{\sim}168mg\;kg^{-1}$ respectively.

• Advances in materials Research
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• v.2 no.1
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• pp.15-36
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• 2013

Incorporation of polar functional moieties into polyethylene (PE) film has been achieved by graft copolymerization of polar monomers such as methacrylic acid (MAAc) and acrylamide (AAm) on to PE film, preirradiated with ${\gamma}$-rays from $^{60}Co$ source, using benzoyl peroxide (BPO) as initiator in aqueous medium. Percentage of grafting of MAAc and AAm was determined as a function of irradiation dose, monomer and initiator concentration, temperature, reaction time and amount of water. Maximum percentage of grafting of MAAc (1453%) and AAm (21.28%) was obtained at [MAAc] = $235.3{\times}10^{-2}$ mol/L, [AAm] = $23.4{\times}10^{-2}$ mol/L, [BPO] = $5.5{\times}10^{-2}$ mol/L and $16.5{\times}10^{-2}$ mol/L at $80^{\circ}C$, $90^{\circ}C$ in 180 min and 90 min respectively. The grafted PE films were characterized by FTIR, Thermogravimetric analysis (TGA) Scanning Electron Micrography (SEM) and X-ray diffraction methods. Some selective properties of grafted films such as swelling behavior, ion and metal uptake have been carried out. The biodegradation studies of the grafted PE films have also been investigated. The grafted films developed superior swelling behavior with maximum swelling (480%) in water as compared to pristine PE (13.55%), better thermal stability and ion and metal uptake studies showed promising results that can be effectively used for desalination of brackish water and separation of metals from the industrial effluents.

• Electrical & Electronic Materials
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• v.8 no.3
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• pp.316-323
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• 1995

A vital step in magnetic tape manufacturing is the surface modification of polymer substrate prior to ink application. A critical element for good adhesion of magnetic ink on polymeric substrate is the ability to join ink in cost-effective manner. Corona discharging is one of the effective methods of modifying polymer surface to improve adhesion while maintaining the desirable properties of the film itself. Surface treatment by corona which is exposure of film surface to electron or ion bombardment, rather than mere exposure to active species, like atomic oxygen or ozone, can enhance adhesion by removing contaminant, electret, roughening surface, and/or introducing reactive chemical groups. Reactive neutrals, ions, electron and photons generated during the corona treatment interact simultaneously with polymers to alter surface chemical composition, wettability, and thus film adhesion. However, it is highly recommended that extensive chains scission be avoided because it can lead to side-effect by forming sticky matter, resulting in dropouts. This paper reviews principles of surface preparation of polymer substrate by corona discharging. In addition, the experimental section provides a description of parameter optimization on corona discharging treatment and its side-effect. Experimental results are discussed in terms of surface wetting as determined by contact angle measurements.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.4
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• pp.416-419
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• 1986

This study was carried out to evaluate the influence of lodging artificially induced and the lodging control of prop on seed yield and other important agronomic characters in sesame. At mono cropping with white polyethylene film mulching and after barley cropping with black polyethylene film mulching as main plot, with three varieties as sub plot and four lodging degree as sub-sub plot with three replications. Plant height was rather increased by the normal and severe lodging, whereas 1,000 seed weight, stem length bearing capsules and number of capsule per plant were significantly decreased. Consequently, yield reduction was resulted in lodging and normal plot as compare to that in lodging control with prop plot. Especially, high yielding in the prop treated was remarkable.

• Macromolecular Research
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• v.14 no.4
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• pp.430-437
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• 2006

The ultra-drawing process of an ultra high molecular weight polyethylene (UHMWPE) gel film was examined by incorporating linear low-density polyethylene (LLDPE) and $BaTiO_3$ nanoparticles. The effects of LLDPE and the draw ratios on the morphological development and mechanical properties of the nanocomposite membrane systems were investigated. By incorporating $BaTiO_3$ nanoparticles in the UHMWPE/LLDPE blend systems, the ultra-drawing process provided a highly extended, fibril structure of UHMWPE chains to form highly porous, composite membranes with well-dispersed nanoparticles. The ultra-drawing process of UHMWPE/LLDPE dry-gel films desirably dispersed the highly loaded $BaTiO_3$ nanoparticles in the porous membrane, which could be used to form multi-layered structures for electronic applications in various embedded, printed circuit board (PCB) systems.

• International Journal of Highway Engineering
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• v.4 no.1 s.11
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• pp.161-170
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• 2002

This study is a fundamental research for recycling waste polyethylene film(WPF) in asphalt concrete for roadway pavement. The objective of this study is to develop technology of making waste polyethylene asphalt mixture and evaluate properties of the asphalt concrete containing WPF. Asphalt concrete for surface course of pavement was produced through an appropriate mix-design using dense-graded and gap-graded aggregates. Marshall mix design, indirect tensile strength test, wheel tracking test and tensile fatigue test were performed. Test result showed that some WPF asphalt mixtures had a high tensile property and good resistances against rutting and fatigue cracking, compared with normal asphalt mixture.