• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.382-382
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• 2021

인간이 만들어내는 미세플라스틱은 물환경시스템과 관련하여 다양한 측면에서 영향을 미치고 있지만, 담수환경에서의 미세플라스틱의 생성, 운송, 축적, 그리고 영향 등에 대한 연구는 매우 제한적으로 이루어지고 있다. 담수환경에서의 미세플라스틱에 대한 보다 나은 이해와 관리를 위해서는 미세플라스틱이 어떤 오염원과 유사한 거동을 보이는지, 또 어떤 인간활동과 밀접한 관계를 가지는지 등에 대한 분석하는 것이 매우 중요하다. 따라서 본 연구에서는 담수 미세플라스틱의 실측자료가 확보된 한강유역을 대상으로 담수 미세플라스틱과 측정망 수질항목(pH, BOD, DO, T-N, T-P, SS) 및 토지이용과의 상관관계를 분석하였다. 본 연구결과로부터 담수 미세플라스틱의 가능한 거동과 관리방안을 논의하였다.

• Journal of Life Science
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• v.33 no.8
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• pp.680-691
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• 2023

Peak oil, climate change, and microplastics caused by the production and usage of petroleum-based plastics have threatened the sustainability of our daily life, and this has emerged as a recent global issue. To solve this global issue, the production and usage of biodegradable eco-friendly bioplastics such as polyhydroxyalkanoates (PHAs) has been suggested as an alternative. Therefore, in this review, the present status of global PHA manufacturers, the advantages of the production of PHAs using marine-origin microorganisms (with their productivity potential) and further required research and development strategies for cost-competitive production of PHAs using marine-based microorganisms were investigated. In this review, PHAs produced from marine microorganisms were found to have similar physical properties to petroleum-based plastics but with several advantages that can reduce the costs of PHA production. Those advantages include, seawater used in the medium preparation step, and osmotic-based cell lysis technology used in the separation and purification steps. However, the PHA productivities from marine microorganisms showed somewhat lower efficiencies than those from the commercial strains isolated from terrestrial environments. In order to solve the problem, further research strategies using synthetic microbiology-based technology, the development of long-term continuous culture technology, and solutions to improve PHA efficiency are required to meet future market demands for alternative bioplastics.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 2003.10a
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• pp.85-85
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• 2003

저장용기(알루미나, 바이오, 스텐레스, 플라스틱)에 따른 김치의 품질특성을 구명하고자 4$^{\circ}C$+1에 31일간 저장하면서 pH, 산도, 환원당, 염도, 유산균, 관능평가 및 조직감등을 비교, 조사하였다. 저장기간에 따른 김치의 pH, 산도의 변화는 알루미나 용기에서 가장 적었고 플라스틱 용기에서 가장 크게 나타났다. 환원당의 경우 저장초기 22.65$\pm$0.04 mg/mL 이었고 저장후기에는 알루미나가 11.18$\pm$0.15$^{a}$ mg/mL이었고, 스텐레스, 바이오, 플라스틱이 각각 5.39$\pm$0.02$^{b}$ , 3.74$\pm$0.$10^{c}$ , 3.14$\pm$0.05$^{d}$ 이었다. (중략)

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.2
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• pp.97-104
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• 2022

This study investigated the characteristics for the optimal concentration of addition of the mixing solution through the corn husk pulverization and surface modification of biomass byproducts adding mixed solution between ESO and silane. And surveyed the specific surface area, water absorption, particle size and physical properties of bio- degradable plastic sheet. The specific surface area was 1.105 m²/g, particle size was the highest at 19 ㎛. The impact strength, tensile strength, elongation and hardness of plastic sheet showed the highest at the 1% concentration among the mixing solutions. The flexural strength and modulus was high according to the increasing the mixing solution. The results above showed that it was the best the adding 1% of mixed solution after silane treatment of corn husks for its manufacture as a bio-based plastic sheet.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.135-144
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• 2016

Due to the high price volatility and environmental concern of petroleum, biofuels such as bioethanol produced from lignocellulosic biomass have attracted much attention. It is also expected that the amount of lignin residue generated from pretreatment of lignocellulosic biomass will increase as the volume of cellulosic bioethanol increases. Lignin is a natural aromatic polymer and has very complex chemical structures with chemical functional groups. Chemical modification of lignin such as oxypropylation and epoxidation has also been applied to the production of value-added bioplastics such as polyurethane and polyester with enhanced thermal and mechanical properties. In addition, lignin can be used for carbon fiber production in automobile industries. This review highlights recent progresses in utilizations and chemical modifications of lignin for the production of bioplastics, resins, and carbon fiber.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.474-474
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• 2022

미세플라스틱이 물 환경으로 배출되는 주요 경로로는 하수처리장 방류수와 강우유출수가 있다. 하수처리장 및 유역에서 배출된 미세플라스틱은 하천과 하구역을 거쳐 해양과 같은 대규모 수역으로 이동하는데, 이 과정에서 해양뿐만 아니라 담수호, 저수지 등과 같은 공공수역에도 미세플라스틱이 지속적으로 축적되고 있다. 특히 강우유출수에 포함된 미세플라스틱은 적절한 처리 과정 없이 하천으로 유입되는 경우가 많아 공공수역 내 미세플라스틱 저감 기술의 필요성이 증가하고 있다. 그러나 미세플라스틱 관련 기존 연구는 미세플라스틱의 분포 등 현황에 대한 모니터링 및 환경위해성과 관련한 것이 대부분이며, 미세플라스틱 저감기술 관련 연구 또한 일부 정수처리 및 하수처리 공정을 대상으로 하는 초기 단계의 연구가 진행되고 있을 뿐 공공수역에서의 미세플라스틱 저감기술 개발 관련 연구는 전무한 실정이다. 따라서, 본 연구에서는 기존의 물리·화학적 수처리 공정인 용존공기부상법(Dissolved Air Flotation, DAF)에 물의 전기분해 시발생하는 브라운가스를 활용하여 응집된 물질을 빠르게 부상시켜 수체 내 오염물질을 제거할 수 있는 기술을 통해 수체 내 미세플라스틱 저감효과를 분석하였다. 또한, 해당 기술을 공공수역인 저수지에 적용하여 오염물질과 함께 미세플라스틱을 제거할 수 있는지 검토하였다.

• The Korean Journal of Food And Nutrition
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• v.17 no.1
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• pp.80-85
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• 2004

This study was performed to provide basic quality characteristics data of Kimchi by storage containers that will be applied for Kimchi storage container development of new material. In all storage containers, pH was decreased with increased storage days, while acidity was increased with increased storage days, The changes of pH and acidity by storage containers were alumina < stainless < bio < plastic. Salt content was same to all containers. In all storage containers, reducing sugars of Kimchi at first were 22.65${\pm}$0.04$\^$a/ mg/mL. But as these of alumina, stainless, bio and plastic at storage after 31 days were 11.18${\pm}$0.15$\^$a/ mg/mL, 5.39${\pm}$0.02$\^$b/, 3.74${\pm}$0.10$\^$c/, and 3.14${\pm}$0.02$\^$d/ mg/mL, respectively. The hardness, cohesiveness and gumminess of Kimchi by storage containers decreased with increased storage days. And the changes ratio of these were alumina < stainless < bio < plastic. The desirable organoleptic characteristic such as sourness, fresh cabbage taste and firmness were long time maintained at alumina container A significant evidence was detected that the alumina container showed less quality change than that of bio, stainless and plastic containers as storage days increased.

• Korean Journal of Food Science and Technology
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• v.40 no.4
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• pp.365-374
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• 2008

Plastics are comparatively new polymeric materials that are manufactured by chemical synthesis, making them different from natural materials such as wood, paper, stone, metal, and glass. Due to a wide range of properties, including processing capabilities and duration, plastics have become rapidly ubiquitous, being used in all industries, and have improved our quality of life. However, it is true that plastics cause environmental contamination problems that have become important social issues, such as environmental hormone leakage due to incineration or reclamation, difficulty in securing reclamation sites, and deadly poisonous dioxin generated by the incomplete incineration of waste plastic materials. To solve these problems, it is urgent to develop and commercialize degradable plastics that can be stably and conveniently used just as general plastics, and that are easily decomposed by sunlight, soil microbes, and heat generated from reclaimed land after use. This review presents recent worldwide trends in the development and marketing of environmentally degradable plastics.

• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.115-124
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• 2020

Sustainable plastics can be mainly categorized into (1) biodegradable plastics decomposed into water and carbon dioxide after use, and (2) biomass-derived plastics possessing the carbon neutrality by utilizing raw materials converted from atmospheric carbon dioxide to biomass. Recently, biomass-derived engineering plastics (EP) and natural nanofiber-reinforced nanocomposites are emerging as a new direction of the industry. In addition to the eco-friendliness of natural resources, these materials are competitive over petroleum-based plastics in the high value-added plastics market. Polyesters and polycarbonates synthesized from isosorbide and 2,5-furandicarboxylic acid, which are representative biomass-derived monomers, are at the forefront of industrialization due to their higher transparency, mechanical properties, thermal stability, and gas barrier properties. Moreover, isosorbide has potential to be applied to super EP material with continuous service temperature over 150 ℃. In situ polymerization utilizing surface hydrophilicity and multi-functionality of natural nanofibers such as nanocellulose and nanochitin achieves remarkable improvements of mechanical properties with the minimal dose of nanofillers. Biomass-derived tough-plastics covered in this review are expected to replace petroleum-based plastics by satisfying the carbon neutrality required by the environment, the high functionality by the consumer, and the accessibility by the industry.

• Journal of Energy Engineering
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• v.19 no.4
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• pp.221-227
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• 2010

In this study, we consider gas generation characteristics on pyrolysis of eco-fuel which were made by mixing of Pitch Pine and Lauan sawdust as biomass and polyethylene, polypropylene, polystyrene as municipal plastic wastes with catalyst in fixed bed reactor. From the result of higher heating value(HHV) measurement and of ultimate analysis, the heating value of plastic wastes and a hydrogen content in plastic sample are higher than biomass. An activation energy was reduced by a catalyst addition. However the catalyst content influence over 5 wt% was insignificant. The yield of hydrogen from gasification of biomass containing plastic wastes such as polyethylene, polypropylene and polystyrene were obtained higher than that of sole biomass. The high temperature and mixture ratio of catalyst conditions induced to high hydrogen yield in most of the samples. As the influence of catalyst, the hydrogen yield by catalytic reaction was higher than non-catalytic reaction. We confirmed that Ni-$ZrO_2$ catalyst is more active in increasing the hydrogen yield in comparison with that of carbonate catalyst. The maximum hydrogen yield was 65.9 vol.%(Pitch Pine / polypropylene / 20 wt.% Ni-$ZrO_2$(1:9) at $900^{\circ}C$).