• Title, Summary, Keyword: Polyethylene Container

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The Stability of Chlorobutanol Solution in Polyethylene and Glycol-modified Polyethylene Terephthalate Containers (Polyethylene과 Glycol-modified Polyethylene Terephthalate 용기내에서의 Chlorobutanol용액의 안정성)

  • Min, Shin-Hong;Kwon, Jong-Won;Jheong, Gu-Choong
    • Journal of Pharmaceutical Investigation
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    • v.16 no.1
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    • pp.8-11
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    • 1986
  • There have been many difficulties in utilization of polyethylene (PE) container for volatile ingredients because of its high permeability. We selected glycol-modified polyethylene terephthalate (PETG) lately being used and evaluated the stability of 0.5% chlorobutanol solution for PETG. We used PE bottle, glass flask and rubber stoppered vial for comparison and assayed chlorobutanol contents of the samples stored at various temperatures for nine weeks by HPLC method. The results indicated that the stability of chlorobutanol in PETG container was almost similar to that in glass flask, and was superior to that in PE bottle and rubber stoppered vial.

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Quality Characteristics of Kimchi Fermented in Permeability-Controlled Polyethylene Containers (투과도 조절 플라스틱 용기에서 발효된 김치의 품질 특성)

  • Lee, Eun-Ji;Park, So-Eun;Choi, Hye-Sun;Han, Gwi-Jung;Kang, Soon-Ah;Park, Kun-Young
    • Korean Journal of Food Preservation
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    • v.17 no.6
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    • pp.793-799
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    • 2010
  • Kimchi was fermented in permeability-controlled polyethylene containers, in glazed onggi (Korean ethnic earthenware) or glass bottles at $5^{\circ}C$ for 8 weeks. During 4 weeks of storage, kimchi fermented in the permeability-controlled container showed a stable fermentation pattern, in terms of changes in pH and acidity, compared with kimchi fermented in the other containers. With respect to changes in bacterial counts, kimchi fermented in polyethylene containers showed vigorous multiplication of lactic acid bacteria, especially Lactobacillus sp., but slow growth of total aerobic bacteria. The springiness of kimchi fermented in the polyethylene containers was optimal (about 10% more than that of glass bottle-fermented kimchi), and the overall acceptability and hardness of container-fermented kimchi were excellent upon sensory evaluation. The DPPH radical-scavenging activity of kimchi fermented in polyethylene containers was also greater (91%) than that of kimchi fermented in glazed onggi (73%) or glass bottles (63%). The $O_2$ and $CO_2$ permeabilities of the polyethylene containers were higher (458 and $357\;mmol\;h^{-1}\;m^{-2}\;atm^{-1}$, respectively) than were those of the other containers; the permeability ratio was 0.8. Glass bottles showed no permeance. The results indicate that permeability-controlled polyethylene containers may be used for kimchi fermentation.

Mathematical Simulation for the Prediction of the Shelf Life of Tofu Packaged in a Polyethylene Container (폴리에틸렌 필름으로 포장된 두부의 보관수명 예측을 위한 수치모사)

  • Kim, Jai Neung;Rim, Byung-O;Shon, Tae-Won;Chung, Gui-Yung
    • Applied Chemistry for Engineering
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    • v.9 no.6
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    • pp.889-893
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    • 1998
  • In this research, mathematical models for predicting the shelf life of packaged tofu in a polyethylene container were developed. Transfer of oxygen in air through the package and then diffusion of oxygen into the filled water and the tofu with the simultaneous oxygen consumption by micoorganisms were studied. The results of simulation showed that the increase of microorganisms in the filled water was more than that in tofu. As a result, it turns out that the shelf life of packaged tofu was not determined by the number of microorganisms in the tofu, but by that in the filled water. Additionally, the effects of physical properties of packaging material and packaged materials, such as the oxygen permeability of packaging material, oxygen diffusion coefficient and the initial oxygen concentration in filled water, and the depth of the filled water, on the shelf life of packaged tofu, were observed.

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Optimization of shielding to reduce cosmic radiation damage to packaged semiconductors during air transport using Monte Carlo simulation

  • Lee, Ju Hyuk;Kim, Hyun Nam;Jeong, Heon Yong;Cho, Sung Oh
    • Nuclear Engineering and Technology
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    • v.52 no.8
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    • pp.1817-1825
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    • 2020
  • Background: Cosmic ray-induced particles can lead to failure of semiconductors packaged for export during air transport. This work performed MCNP 6.2 simulations to optimize shielding against neutrons and protons induced by cosmic radiation Methods and materials: The energy spectra of protons and neutrons by incident angle at the flight altitude were determined using atmospheric cuboid model. Various candidates for the shielding materials and the geometry of the Unit Load Device Container were evaluated to determine the conditions that allow optimal shielding at all sides of the container. Results: It was found that neutrons and protons, at the flight altitude, generally travel with a downward trajectory especially for the particles with high energy. This indicated that the largest number of particles struck the top of the container. Furthermore, the simulation results showed that, among the materials tested, borated polyethylene and stainless steel were the most optimal shielding materials. The optimal shielding structure was also determined with the weight limit of the container in consideration. Conclusions: Under the determined optimal shielding conditions, a significantly reduced number of neutrons and protons reach the contents inside the container, which ultimately reduces the possibility of semiconductor failure during air transport.

Quality Changes of Brined Baechu Cabbage Prepared with Low Temperature Stored Baechu Cabbages (저온 저장 생배추를 이용하여 제조한 절임배추의 저장기간 중 품질 특성의 변화)

  • Jeong, Ji-Kang;Park, So-Eun;Lee, Sun-Mi;Choi, Hye-Sun;Kim, So-Hee;Park, Kun-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.3
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    • pp.475-479
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    • 2011
  • Although the storage period of raw baechu cabbage could be 2 months at $0{\sim}2^{\circ}C$, 1 month was appropriate considering the quality of the baechu cabbage, waste ratio, and storage cost. The polyethylene container was the most efficient storage container among polypropylene box, polypropylene net and polyethylene container. pH of a brined baechu cabbage using raw baechu cabbage was 4.0~4.3 after 8 weeks and its total bacteria and lactic acid bacteria counts were $10^7$ cfu/g, and textural property (springiness) lower than 50% was at 8th week of storage at $0{\sim}2^{\circ}C$ and thus its storage period was limited to 8 weeks. When brined baechu cabbage was prepared by raw baechu cabbage stored for 1 month at $0{\sim}2^{\circ}C$, its pH, microorganism counts and springiness showed similar trends to the brined cabbage using raw baechu stored for 0 month. However, its rates of change were faster than the brined baechu cabbage using the raw baechu, and the storage period was limited to 6 weeks. Brined baechu cabbage using the raw cabbage stored for 2 months and its storage period was limited by about 4 weeks judging by its indicated quality characteristics.

Freshness Comparison of Lettuce (Lactuca sativa L.) in accordance with Storage and Packaging Method on High-temperature Period (결구상추 고온기 포장 및 저장방법에 따른 신선도 비교)

  • Bark, Doe-Ey;Yoon, Yi-Na;Woo, Ye Jinn;Cheung, Gum Hang;Hwang, Sae Bom;Park, SuHyoung;Woo, Young-June;Shin, Chul;Choi, Dong-soo;Lim, Junhyung;Park, See Eun;Lee, Jung-Soo
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.21 no.1
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    • pp.35-40
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    • 2015
  • Effect of packaging and storage methods for enhancing the shelf life and improving the postharvest quality of lettuce (Lactuca sativa L.) was studied during high temperature period. Lettuces were packed using four packaging and storage types: (A) plastic box container (control); (B) plastic box container covered with high density polyethylene (HDPE) film; (C) plastic box container with lettuce wrapped in linear low-density polyethylene (LLD-PE) film; and (D) plastic box container with lettuce with its stem. The quality parameters, such as fresh weight loss, SPAD value, and appearance of lettuce were investigated. The lettuce wrapped with LLD-PE film inside the plastic box container showed the lowest weight loss, highest SPAD value and best appearance compared to those exposed to the other packaging and storage methods during the three-week storage at $2^{\circ}C$. The results indicate that the marketability of lettuce can be optimized if proper packaging and storing is adopted. Prolonging the freshness even on low temperature storage will increase the potential of its sale ability in the domestic market even during summer season.

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Optimization of Solid-State Fermentation for Improved Conidia Production of Beauveria bassiana as a Mycoinsecticide

  • Pham, Tuan Anh;Kim, Jeong-Jun;Kim, Keun
    • Mycobiology
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    • v.38 no.2
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    • pp.137-143
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    • 2010
  • The production of conidia of entomopathogenic Beauveria bassiana by solid-state fermentation was studied for the development of a biocontrol agent against aphid Myzus persicae. The optimal conditions for conidia production on polished white rice were 40% moisture content, $25^{\circ}C$ culture temperature, 2-day-old seeding culture grown in 3% corn meal, 2% rice bran, 2% corn steep powder medium, initial conidia concentration of $10^7$ conidia/g in the wet rice, 10% inoculum size, and use of a polyethylene bag as a container. The polyethylene bag containing inoculated rice was hand-shaken every 12 hr during fermentation. Using optimal conditions, the maximum conidia production obtained was 4.05 g conidia/100 g dry rice after 14 days of cultivation, a rate 2.83 times higher than conidia yield of pre-optimization.

A Study on Storage Media of the Heat Storage System for a Vehicle (자동차 축열시스템의 저장매체에 관한 연구)

  • Kim, H.C.;Song, Y.H.;Lee, C.T.
    • Applied Chemistry for Engineering
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    • v.7 no.4
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    • pp.726-734
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    • 1996
  • This study was carried oui to find a proper heat storage material and iris container for the thermal energy recovery system of a vehichle. For this purpose, various phenomenon during phase change from solid to liquid and vice versa for three kind material, octahydrate barium hydroxide, naphthalene and acetamide, are experimentally investigated. Also three type material such as pyrex glass, polyethylene and cupper are tested the feasibility as being a container of heat storage material. From this experimental results, $Ba(OH)_2{\cdot}8H_2O$ showed high possibility as good storage media with condition of long life cycle and stable phase change, and cupper was found out as proper container of $Ba(OH)_2{\cdot}8H_2O$.

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Optimum Management for Overwintering of Pinus densiflora Container Seedlings (소나무 용기묘의 적정 월동 관리)

  • Kim, Jong Jin;Song, Kook Hyun;Yoon, Taek Seong
    • Journal of Korean Society of Forest Science
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    • v.97 no.1
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    • pp.53-60
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    • 2008
  • This study was carried out to investigate the optimum management system during a overwintering for the production of Pinus densiflora container 2-0 seedlings. The experiment performed between 2005~2006 in a polyethylene film house (PE house) located at Yeoju-Gun in Kyungki-Do. During the winter in the PE house, the difference in maximum day temperature and minimum day temperature was large, and the difference in temperature was detected between the container keeping locations. During the winter season, the maximum day temperatures at the seedling bench in January and February were $32.8^{\circ}C$ and$36.6^{\circ}C$, respectively, whereas those at the ground in January and February were $16.0^{\circ}C$ and $24.4^{\circ}C$, respectively. Water contents of container seedlings was reduced gradually from the beginning the experiment, and reduced rapidly from February to March, and increased rapidly from April. Container seedlings showed different death rate according to the extending of the irrigation cycle. Death rate by one week and two weeks of irrigation cycle was 4.8% and 6.5%, and 38.5% and 49.4% of death rate occurred by three and four weeks of irrigation cycle, respectively. It is suggested that the proper irrigation cycle for P. densiflora 2-0 container seedlings during overwintering is two weeks. When containers placed directly on the ground, the root of container seedlings went out through the drainage of the container, and grew out in the soil. These roots were cut while moving the container to the bench in spring.

Cultivation of Paecilomyces tenuipes using Mini-kit, small culture container (소규모 재배상을 이용한 생동충하초 재배)

  • Nam, Sung-Hee;Lee, Kwang Gill;Yeo, Joo Hong;Lee, Heui Sam;Hwang, Jae Sam;Choi, Young-Cheol;Park, Kwan-Ho
    • Journal of Sericultural and Entomological Science
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    • v.50 no.2
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    • pp.116-121
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    • 2012
  • Cordyceps and its allies fungi has been described as a secret medicine that gives eternal youth and a long life. Some species of Cordyceps are sources of biochemicals, such ascordycepin, with interesting biological and pharmacological properties. Hence, it has been studied to uncover its pharmacological effect. We attempted to study the formation of fruiting bodies and to develop means of mass production Korean isolate of Paecilomyces tenuipes has been inoculated into silkworms, where it reproduced using culture container, mini-kit successfully. Culture container, mini-kit is composed of a cylinder-shaped body and lid. The container is made of translucent polyethylene terephthalate. The size of the container is $82{\times}75mm$, reduced by 10 times as compared with the conventional culture kit. The mini kit has many advantages - high culture amount, ability of maintaining optimal humidity, parasite-free cultivation and high-end appearance. With the kit, the optimal cultivation condition is under $22^{\circ}C$, culture period of 53 days. And synnemata of P. tenuipes could be kept fresh for 14 days at the temperature of under $10^{\circ}C$. Therefore, the Min-kit can be used in both ways as a culture container and a packing kit for end-user customers.