• Title/Summary/Keyword: recyclable

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A Study of Dominant Microorganisms in Waste Handling Industries (폐기물 취급 업종에서 우점하는 미생물에 대한 평가)

  • Park, Hae Dong;Park, Hyunhee
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.23 no.2
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    • pp.84-94
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    • 2013
  • Objectives: The objective of this study is to identify the composition of dominant microorganisms in waste handling industries. Methods: We collected airborne bacteria and fungi by agar plate impaction method in recyclable waste sorting industry, food recycling industry, landfill and incineration. Isolated dominant microorganisms were identified by VITEK system or morphological analysis. Results: We isolated totally 330 microorganisms in the process and outdoor. Bacillus was the most dominant genus in the all industries, and Sphingomonas, Acinetobacter, Staphylococcus, and Proteus was dominant bacterial genus. The dominant genus of fungi was Penicillium, Aspergillus, and Cladosporium in each industries. Enterobacter, Pseudomonas, Klebsiella, and Proteus was identified as the dominant gram negative bacteria. The ratio of bacteria being biosafety levels(class 1 or 2) was 58.3~77.8%. Conclusions: This study has investigated the dominant microorganisms in the waste handling industries. The genus of dominant microorganisms was similar among the industries but the composition was different. We used biosafety levels as qualitative method, but further studies are needed about specific process of qualitative evaluation methods.

The Effect of the Recycling Industry in Public Sector (공공부문 자원재활용사업의 국민경제적 효과분석)

  • Kwak, Seung-Jun;Yoo, Seung-Hoon;Ryu, Mun-Hyun
    • Environmental and Resource Economics Review
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    • v.11 no.3
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    • pp.465-491
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    • 2002
  • Korea is one of the countries which have a remarkable record of high and sustained economic growth. However, as the national economy has continued to grow and the industrial structure has become increasingly advanced, the amount of wastes being generated has been rapidly on the rise. recycling wastes to cope with the environmental problems caused by wastes has become an increasingly important policy issue in developing countries such as Korea, as well as in developed countries. This situation demands that researchers provide policy-makers with available and responsible information regarding the effect of the recycling industry in the public sector. This study employs input-output (I-O) analysis to examine the effect of public sector recycling industry in the national economy, using a specific application to Korea. The paper, therefore, has two major goals. The first is the development of a static I-O framework for looking into the effect of public sector recycling industry in the short run. The second goal is obtaining at least a preliminary indication of the effect of the recycling industry- in public sector. Moreover, we discuss the role of a public firm that established with an objective of promoting and facilitating the reutilization of recyclable wastes. The overall results indicate that the recycling utilities may have a significant influence on the standard of living and industrial production.

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Immobilized ${\beta}-Cyclodextrin$ as a Simple and Recyclable Method for Cholesterol Removal in Milk

  • Kwak, H.-S.;Kim, S.-H.;Kim, J.-H.;Choi, H.-J.;Kang, J.
    • Archives of Pharmacal Research
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    • v.27 no.8
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    • pp.873-877
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    • 2004
  • This study was designed to determine the optimum conditions of three different factors (mixing time, mixing temperature, and tube size) in reduction of cholesterol in milk using immobilized $\beta$-CD beads. Immobilized $\beta$-CD glass beads were prepared at different conditions of silaniza-tion and $\beta$-CD immobilization reactions. In result, the glass beads (diameter 1 mm) at 20 mM 3-isocyanatopropyltriethoxysilane and 30 mM $\beta$-CD without base showed the highest choles-terol removal rate as 41%. Using above immobilized $\beta$-CD glass beads, the cholesterol removal rate was 40.2% with 6 h of mixing time in 7 mm diameter tube at $10^{\circ}C$. After choles-terol removal from milk, the glass beads were washed for cholesterol dissociation and reused. In recycling study, the cholesterol removal rate was 41%, which was mostly same as that using new glass beads. These results indicated that cholesterol removal rate was about 40% with $\beta$-CD immobilized glass beads, however, the recycling efficiency was almost 100%.

Fire Retardancy and Mechanical Properties of Paper Sludge-Wood Particle Mixed Board (제지 슬러지-목재 파티클 혼합보드의 내화성과 기계적 성질)

  • Son, Jung-Il;Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
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    • v.22 no.1
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    • pp.54-65
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    • 1994
  • This research carried out to investigate the effects of inorganic materials in paper sludge on the thermal degradation and of paper sludge addition on physical and mechanical properties of paper sludge-wood particle mixed boards in comparison with unmodified particleboards. Also these unmodified particleboards and paper sludge-wood particle mixed boards were soaked in aqueous solutions of fire-retardant chemicals(diammonium phosphate and zinc chloride), and their fire retardancy were tested by oxygen index method and ISO ignition test to determine the feasibility of paper sludge, industrial waste, as a recyclable resource in fabrication of fire-resisting panels for building material. Since the redrying of fire-retardant treated particleboards and paper sludge-wood particle mixed boards were made by press drying method, this process was a simple and effective method. On the other hand, flexural bending strength and internal bonding strength were also analysed to evaluate mechanical properties through standard method.

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Nanofilm Transfer Methods and Interfacial Fracture Mechanics (나노박막 전사 방법 및 계면 파괴 역학)

  • Kang, Sumin;Kim, Taek-Soo
    • Journal of the Microelectronics and Packaging Society
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    • v.27 no.3
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    • pp.9-19
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    • 2020
  • Transferring of functional nanofilms onto target substrates is a cornerstone to developing nanofilm-based nextgeneration applications. In this work, we provide a brief review of recent advances on nanofilm transfer methods by categorizing them into the following three methods: wet-etching transfer, electrochemical delamination, and mechanical transfer. Furthermore, the mechanical transfer method, which is regarded as a promising technology owing to its facile, substrate recyclable, and widely applicable process, is overviewed by focusing on fracture mechanics approaches. Finally, the perspectives and challenges for future development of the mechanical transfer method are discussed.

Development and mechanical properties of bagasse fiber reinforced composites

  • Cao, Yong;Goda, Koichi;Shibata, Shinichi
    • Advanced Composite Materials
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    • v.16 no.4
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    • pp.283-298
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    • 2007
  • Environment-friendly composites reinforced with bagasse fiber (BF), a kind of natural fiber as the remains from squeezed sugarcane, were fabricated by injection molding and press molding. As appropriate matrices for injection molding and press molding, polypropylene (PP) and polycaprolactone-cornstarch (PCL-C) were selected, as a typical recyclable resin and biodegradable resin, respectively. The mechanical properties of BF/PP composites were investigated in view of fiber mass fraction and injection molding conditions. And the mechanical properties and the biodegradation of BF/PCL composites were also evaluated. In the case of injection molding, the flexural modulus increased with an increase in fiber mass fraction, and the mechanical properties decreased with an increase in cylinder temperature due to the thermal degradation of BF. The optimum conditions increasing the flexural properties and the impact strength were $90^{\circ}C$ mold temperature, 30 s injection interval, and in the range of 165 to $185^{\circ}C$ cylinder temperature. On the other hand, as to BF/PCL-C fully-green composites, both the flexural properties and the impact strength increased with an increase in fiber mass fraction. It is considered that the BF compressed during preparation could result in the enhancement in mechanical properties. The results of the biodegradability test showed the addition of BF caused the acceleration of weight loss, which increased further with increasing fiber content. This reveals that the addition and the quantities of BF could promote the biodegradation of fully-green composites.

A Study of Product Design using Recycled Materials

  • Kim, Kwan-Bae;Chung, Do-Seung;Jang, Jung-Sik
    • International journal of advanced smart convergence
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    • v.9 no.1
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    • pp.70-81
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    • 2020
  • Plastics that we use and simply throw away have a life span of about 500 years and barely decompose. The practice of producing and using common plastics needs to be challenged. Until now, they have been useful in the industrial structure of mass production, but it can be said that there is a lack of research into new materials to introduce and apply in terms of material recycling. As a result of this, we have come to the uncomfortable realization of the fact that we cannot incinerate or reuse these precious resources indiscriminately. No matter how well-designed a product is, it has a competitive advantage if production and consumption activities, waste, collection, sorting and treatment are considered in terms of a continuous cycle, and in this respect, Extended Producer Responsibility (EPR) can help. We are implementing the EPR system, and active industrialization in the field of recycling is required, which is also a challenge for producers to participate actively in recycling and seek to save and recycle resources in design and manufacturing. Against this backdrop, We would like to examine the possibilities, through various studies and developments on product design of recyclable materials, which is being conducted mainly in Europe. In particular, we would like to examine the methods, and value of solving environmental problems and the active efforts to achieve this in the design world, and in particular the case of product design using recycled plastics.

The Performance and Evaluation for Recycling of Waste Glass

  • Chang, Tein-Chin;Huang, Jian-Er;Yen, Jia-Huei
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.80-83
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    • 2001
  • According to the EPA in Taiwan report, 9.05 million metric tons of solid wastes were generated in 1999, and the waste glass was accounted of 4.95 percent. However, with the increasing tonnage of disposal cost and existing disposal sites are reaching full capacity, recycling is currently accepted as a sustainable approach to waste management. Therefore, it's essential and urgent that the government in Taiwan establish the recycling and recovery framework for the minimization of the solid waste, reduction of materials and energy consumption, and the encouragement for the reuse, recycle and recovery development. To achieve this Boal, Taiwan has been strived for a long period of time in waste glass recovery and recycle. Waste glass, unlike other kinds of resource waste, is 100% recyclable. The EPA in Taiwan now center on a lot of different kinds of waste glass, such as glass container, flat glass, CRT glass, windshields glass, fluorescent lamps, and waste pesticide glass container. This article will focus on the framework of the recycling market access, and also try to provide some strategies to improve waste glass recycling efficiently.

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Silica Gel-Supported Polyphosphoric Acid (PPA-SiO2) Catalyzed One-Pot Multi-Component Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones and -thiones: An Efficient Method for the Biginelli Reaction

  • Zeinali-Dastmalbaf, Mohsen;Davoodnia, Abolghasem;Heravi, Majid M.;Tavakoli-Hoseini, Niloofar;Khojastehnezhad, Amir;Zamani, Hassan Ali
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.656-658
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    • 2011
  • A green and efficient method for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and -thiones through one-pot three-component reaction of ethyl acetoacetate, an aryl aldehyde, and urea or thiourea in acetonitrile using silica gel-supported polyphosphoric acid (PPA-$SiO_2$) as catalyst is described. Compared to the classical Biginelli reaction conditions, the present methodology offers several advantages such as high yields, relatively short reaction times, mild reaction condition and a recyclable catalyst with a very easy work up.

Local activation using traditional knowledge and ecological resources of Korean islands

  • Hong, Sun-Kee
    • Journal of Ecology and Environment
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    • v.38 no.2
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    • pp.263-269
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    • 2015
  • When we consider changes in agro-fishery systems instigated by environmental changes in islands, rise in sea levels, and natural disasters such as tsunamis, there is an urgent need to carry out initiatives to enhance life standard and conserve ecosystem in island and coastal regions. To protect the region's landscape from the effects of climate change, it is necessary to develop an integrated management system for ecosystem conservation, human settlements, and the local economy. This paper discusses the outline of a preliminary national plan for a sustainable island management system for remote (inhabited and uninhabited) islands in Korea. Two main ideas to enhance life standard are adapting to the natural environment by applying traditional knowledge and utilizing ecological resources of islands, i.e., improving the quality of life and creating added value. As a technique for improving the quality of life, the establishment of eco-villages based on energy-efficient passive houses and ecological welfare is suggested. Another technique for creating added value, the development of sea-farming islands that utilize islands' new recyclable energy is also proposed. Finally, the suggested ideas are discussed in relation to island ecotourism and carbon zero islands.