• Food Science and Preservation
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• v.19 no.1
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• pp.7-11
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• 2012

This study was conducted to determine the effects of the humidity and gas composition on the quality of satsuma mandarins during their heat treatment, in an effort to reduce their acidity. To come up with different humidity and gas conditions, various plastic films were used. The fruits were wrapped with an 18-${\mu}m$ high-density polyethylene (HDPE) punched film, a 30-${\mu}m$ low-density polyethylene (LDPE) film, or a 100-${\mu}m$ LDPE film just before treatment at $30^{\circ}C$ for 55 hours. After heat treatment, the titratible acidity (TA) was significantly reduced while the soluble-solid content (SSC) showed no differences, which resulted in increased SSC/TA ratios in all the treatments. The fruits that were not wrapped with a film, however, which had low RH, developed higher ethanol and acetaldehyde contents than those wrapped with an 18-${\mu}m$ HDPE punched film, which had high RH and a similar gas composition. Among the films, the higher the $CO_2$ concentration in the film was, the more the ethanol and acetaldehyde contents increased, which induced more off-flavor. It was thus concluded that high humidity and normal gas composition are favorable conditions for heat treatment to reduce the acidity of satsuma mandarins.

• Food Science and Preservation
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• v.14 no.5
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• pp.457-461
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• 2007

We investigated the effects of both $CaCl_2$ treatment and modified atmosphere packaging (MAP) (compared with non-packaging on 'Fuji' apples from the Young-Joo region of Korea. Apples were dined into 5% (w/v) $CaCl_2$ solution for 15 min and then packaged with or without LDPE film (thickness: 0.025 mm) before cold storage at $0^{\circ}C$. Weight loss of applies in film packaging was lower than that of non-packaging applies, and the apple firmness resulting from $CaCl_2$ treatment and MAP was better than that of apples receiving control treatment. Also, $CaCl_2$ treatment and MAP resulted in improvements in titratable acidity, soluble solid content (SSC), and decay rate compared to control treatments. However, no significant differences in vitamin C content were found amongst apples receiving various treatment. the results suggest that a combination of postharvest calcium dipping and plastic film packaging may effectively preserve 'Fuji' apples, and that the combined treatment are better than either individual treatment.

• Food Science and Preservation
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• v.5 no.4
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• pp.335-338
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• 1998

Weight loss of fear packed with corrugated paperboard box(FC) laminated with functional MA film after 60 days storage at 5$^{\circ}C$ was 1.0%, and that of LDPE, CE film was 0.6-0.7%, while that of control(Corrugated Paperboard box) was 2.8%. Total ascorbic acid content of pear ill MA films and FC package was higher than that of control. Titratable acid of control changed 37%, but that of the others packages changed below 27%. Soluble solid content of control changed 27%, while the others changed below 2%. Reference in overall appearence of pear were not found among packaging methods. Corrugated paperboard box(FC) laminated with Functional MA film can be used as packaging material for pear packaging.

• Food Science and Preservation
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• v.9 no.3
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• pp.271-276
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• 2002

To develop a wrapping film, which suppresses the microbial decay through the storage and prolongs the selflife of fruits and vegetables, the antimicrobial packaging films were prepared and applied to the preservation of strtwberries and cucumbers. Low density polyethylene(LDPE) film of 50㎛ thickness was faricated with 1% of Scutellariae baicalensis extract. The LDPE film impregnated with Scutellariae baicalensis extract showed antimicrobial activity on the disk test against Bacillus cereus, Escherchia coli and Fusarium sp.. The antimicrobial film changed the color and light transmittance, but did not affect heat shrinkage, mechanical tensile strength and wattability. Strawberries and cucumbers were separately wrapped with packaging films in the state of closely-adhered packaging as well as modified atmosphere packaging(MAP). The wrapped strawberries and cucumbers were stored for 21 days at 5$\^{C}$ and for 40 days at l0$\^{C}$, respectively. For the packaged strawberries and cucumbers at 5$\^{C}$ and 10$\^{C}$, the LDPE film impregnated with Scutellariae baicalensis extract showed the reduced growth of total aerobic bacteria, molds and yeasts and did not give any negative effect on other quality attributes during storage in comparison with conttrol film without any additive.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.11a
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• pp.143-146
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• 1994

In older to investigate the properties of electric conduction in low density polyethylene(LDPE) for power cable, the thickness of specimen was the 30, 100($\mu\textrm{m}$) of LDPE. The experimental condition for conductive properties was measured until the breakdown occurs at temperature ranges from 30 to 110[$^{\circ}C$] and in the electric field of 1 to 5 ${\times}$10$^2$[Mv/m]. As for increase of temperature, the current density of LDPE was increased with constant ratio in low field, but changes with exponential function in high field. The tunnel current of pre-breakdown region is shifted toward low field as much as thermal excitation energy.

• Journal of the Korean Society of Safety
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• v.11 no.1
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• pp.67-74
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• 1996

In order to investigate the effect and reliability coming up to properties of the matter due to the change of solid structure in dielectrics, the effect of dielectric characteristics for thermal treated LDPE film was made researches. Specimens of LDPE with thickness 100 [$\mu\textrm{m}$] were investigated into the change of solid structure by ageing. Thermal treated specimen were made, that were after applying heat at 100 [$^{\circ}C$] for 1 [hour] \circled1 air-cooled specimen slowly, \circled2 water-cooled specimen under the ,com temperature, \circled3 liquid nitrogen gas-cooled specimen rapidly. With specimen of thermal treated three types turn out and original, it was for dielectric characteristics to be experimented in the temperature range of 20~120 [$^{\circ}C$], frequency range of 30~1.5${\times}10^5/$[Hz], appling voltage from 300 to 1500[㎷]. Consequently, the degree of crystallinity was changed with 49~57 [%] according to the thermal treatment. In case of frequency, 100 [Hz], on the thermal dependance in dielectric characteristics, tan decreases due to cooling method.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.6 no.1
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• pp.47-52
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• 2000

This study was measured weight loss, total ascorbic acid, titratable acidity, and soluble solids content to investigate the effect of EPS(expanded polystyrene foam) box, LDPE film pouches and double wall corrugated fiberboard box during storage at $20^{\circ}C$. Weight loss of apple packed with corrugated paperboard box after 40 days storage was 5.7%, and those of LDPE, CE film and EPS box were 0.2-0.5%. Ascorbic acid content of apple packed with LDPE, CE, EPS was higher than that of control. Titratable acidity and total soluble solid content of control were changed 40% and 10%, and the EPS were changed 27% and 4%, respectively. Overall appearances of 'Fuji' apple packed with LDFE, CE and EPS were better than that of control.

• Korean Journal of Human Ecology
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• v.9 no.4
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• pp.505-512
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• 2000

The fresh ginseng was packed individually with a soft film bag, ONY/LDPE/L-LDPE (20$\times$30 cm, 93 ${\mu}m$) and stored at $25^{\circ}C$ for twenty days. The Quality-related appearance parameters and the sensory characteristics of the fresh ginseng were evaluated. The quality of the fresh ginseng was lowered mainly due to hardness decrease with increasing storage time, while the occurrence of mould was rarely observed. The normal ginseng had strong fresh ginseng odor and strong bitter taste and its hardness was well maintained during twenty days. The softened ginseng had pungent and sour odor, sweet and sour taste and sticky texture.

• Journal of People, Plants, and Environment
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• v.24 no.2
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• pp.195-207
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• 2021

Background and objective: While response measures to particulate matters in rural areas are limited due to poor inventory record keeping in the agricultural sector, it is necessary to control agricultural waste vinyl and the emission of precursors released from open burning and the secondary generation of particulate matters. Currently, the open burning emission calculation method uses the definition prescribed in CAPSS by the National Institute of Environmental Research. Methods: This study presented an open burning emission calculation formula for agricultural waste vinyl, which is included as agricultural waste. As for activity data, the open burning ratio of agricultural waste vinyl, and the annual incineration volume provided in the Status Survey by the Ministry of Agriculture, Food, and Rural Affairs were applied. The emission factor was generated through incineration tests on three agricultural plastic film samples collected by the Korea Environment Corporation. Results: Among precursors, SOx and NOx were selected and their emission features were monitored with incineration experiment infrastructure based on the EPA 5G method. The highest emission concentration by agricultural waste type was concentrated in the first and second quarters. As for emission factor of SO₂, it was calculated at 98.25 g/kg for mulching-use LDPE, 52.31 g/kg for greenhouse-use LDPE, and 14.40 g/kg for HDPE. As for NOx, it was calculated at 18.21 g/kg for mulching-use LDPE, 16.49 g/kg for greenhouse-use LDPE, and 10.67 g/kg for HDPE. Conclusion: This test confirmed the incineration features of PE-based plastics, ascertained the SOx emission factor that had not been included in open burning in the past, and established that low NOx emission concentration is interfered by soil mixed with livestock excretions. The findings from this study are expected to contribute to improving the system for controlling air pollutants in rural environments.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1908-1910
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• 2001

본 논문은 마이크로머시닝 기술을 이용하여 lift-off 공정으로 패턴닝 한 후 TMAH (Tetramethylammonium Hydroxide) 용액으로 $5{\sim}100{\mu}m$ 두께의 실리콘 다이어프램을 제작하였다. Pt/Ti 박막을 HF 전해질의 mask 물질로 사용하여 HF 용액 내에서 전기화학적 방법으로 정전압을 인가, 다이어프램 영역에 다공질 실리콘을 성장시켜 관통하였다. 140$^{\circ}C$의 질소 분위기에서 $10{\sim}15{\mu}m$두께의 LDPE(Low Density Poly Ethylene) 필름을 물리적으로 다이어프램 영역에 코팅하고 $K_2CO_3$ 용액내에서 ${CO_3}^{2-}$ 이온의 barrier에 의한 전류의 감소를 전기화학적인 분석방법에 의하여 측정하였다. 일정 전압하에서 이온 농도에 기인하는 다공질 실리콘과 LDPE 표면에서 Barrier의 두께에 따른 저항의 증가를 전극으로 감지하여 농도-전류의 특성을 측정하고 이것을 기준으로 하여 미지농도의 $K_2CO_3$ 용액내의 ${CO_3}^{2-}$ 이온 농도를 측정하였다.