• Title/Summary/Keyword: Waste products

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Experimental Assessment of Mechanical Properties of Geo-grid Reinforced Material and Long-Term Performance of GT/HDPE Composite

  • Seo, Jung-Min;Min, Kyung-Ho;Hwang, Beong-Bok;Lee, In-Chul;Ruchiranga, Jayasekara Vishara;Jeon, Han-Yong;Jang, Dong-Hwan;Lim, Joong-Yeon
    • Advanced Composite Materials
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    • v.17 no.3
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    • pp.247-258
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    • 2008
  • This paper is concerned with the long-term performance of geo-textile (GT) composites in terms of creep deformation and frictional properties. Composites of PVA GT and HDPE GM were made to investigate the advanced properties of long-term performance related to waste landfill applications. The same experiments were also performed for typical polypropylene and polyester GT and compared to PVA GT/HDPE GM composites. We also develop high performance GT composites with GM by using PVA GT, which is capable of improving the frictional properties and thus enhances long-term performance of GT composites. Experimental study reveals that the friction coefficient of GT composites is relatively large compared with those of polyester and polypropylene non-woven GT as long as the friction media has similar size to the particles of domestic standard earth. In addition, the geo-composites bonded with geo-grid by a chemical process were investigated experimentally in terms of strain evaluation and creep response values. Geo-grid plays an important role as a reinforcing material. Three kinds of geo-grid were prepared as strong yarn polyester and they were woven type, non-woven type, and wrap knitted type. The sample geo-grids were then coated with PVC. The rib tensile strength tests were conducted to evaluate geo-grid products in terms of tensile strength with regard to single rib. The test was performed according to GRI-GGI. It was concluded again from the experiments that the tensile and creep strains of the geo-grid showed such stable values that the geo-grid prepared in this study could protect geo-textile partially in practical structures.

The Continuous Pyrolysis of Waste Polystyrene using Wetted-Wall Type Reactor (Wetted-Wall Column 형 반응기를 이용한 폐 EPS 연속 열분해반응)

  • Han, Myung Sook;Han, Myung Wan;Yoon, Byung Tae;Kim, Seong Bo;Choi, Myoung Jae
    • Korean Chemical Engineering Research
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    • v.45 no.4
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    • pp.396-399
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    • 2007
  • Organic residue and carbonized solid producing from the thermal degradation gave a influence on oil conversion, formation of styrene and side products such as ${\alpha}-methyl$ styrene, ethyl benzene, dimer. Thus, new reaction system using wetted-wall type reactor was proposed and examined on influence of various parameters such as reaction temperature, feeding rate and removal velocity of formed vapor. Optimum condition were obtained from continuous thermal degradation using wetted-wall type reactor and styrene was continuously obtained as the yield up 65%.

Recycling of Sintered Nd-Fe-B Magnets Doped with PrNd Nanoparticles

  • Zhang, Xuefeng;Liu, Fei;Liu, Yanli;Ma, Qiang;Li, Yongfeng;Zhao, Qian;Wang, Gaofeng;Li, Zhubai
    • Journal of Magnetics
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    • v.20 no.2
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    • pp.97-102
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    • 2015
  • The waste of sintered Nd-Fe-B magnets was recycled using the method of dopingPrNd nanoparticles. The effect of PrNd nanoparticle doping on the magnetic properties of the regenerated magnets has been studied. As the content of the PrNd nanoparticles increases, the coercivity increases monotonically, whereas both the remanence and the maximum energy products reach the maximum values for 4 wt% PrNd doping. Microstructural observation reveals that the appropriate addition of PrNd nanoparticles improves the magnetic properties and refines the grain. Domain investigation shows that the self-pinning effect of the rare earth (Re)-rich phase is enhanced by PrNd nano-particle doping. Compared to the magnet with 4 wt% PrNd alloy prepared using the dual-alloy method, the regenerated magnet doped with the same number of PrNd nanoparticles exhibits better magnetic properties and a more homogeneous microstructure. Therefore, it is concluded that PrNd nanoparticle doping is an efficient method for recycling the leftover scraps of Nd-Fe-B magnets.

Development of the Contents of the Guideline for Dietitians' Knowledge, Attitudes and Practices (KAP) for Sustainable Management at School Foodservice (지속가능경영을 위한 학교급식 영양사의 지식, 태도, 실천 가이드라인 콘텐츠 개발)

  • Yi, Na-Young
    • Journal of the Korean Society of Food Culture
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    • v.32 no.6
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    • pp.513-526
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    • 2017
  • The purpose of this study is to identify the guideline's contents for dietitians' knowledge, attitudes, and practices (KAP) for the sustainability management at school foodservice. The contents for the guideline were determined by the Delphi technique of two rounds. The Delphi panels of experts were consisted of sixteen school dietitians and fourteen professors of food and nutrition with more than 10 years of experiences by convenience sampling method. Based on the literature, knowledge, attitudes, and practices required for dieticians were classified into menu management, procurement, food production, facility and energy management, waste management, personnel management, and nutrition education. Data were analyzed using SPSS for Windows version 24 and EXCEL to calculate descriptive statistics, content validity ratio, degree of agreement, and degree of convergence. As a result of the second round, the validity scores of 'knows eco-friendly certification standards and labeling systems (4.53 point)' in the knowledge category, and 'tries to purchase local agricultural products (4.87 point)' in the attitude category were the highest. From that round in the practice category, the validity scores of 'plan menus for students' health', 'purchases eco-friendly food', and 'conserves energy in pre-processing and cooking process' were the highest with 4.73 point. Applying the criteria for securing the validity of the contents, the contents of 25 knowledge items, 20 attitude items and 30 practice items were confirmed. The findings of the study can be used to develop the guideline for dietitians required for the sustainability management.

Improved Production of Ligninase and Laccase by Phanerochaete chrysosporium and Ceriporiopsis subvermispora (Phanerochaete chrysosporium과 Ceriporiopsis subvermispora 균주(菌株)의 Ligninase 및 Laccase 생산최적조건에 관한 연구(硏究))

  • Kang, An-Seok;Cha, Dong-Yeul;Kim, Kyung-Soo;Hong, In-Pyo;Croan, Suki C.;Yu, Seung-Hun
    • The Korean Journal of Mycology
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    • v.22 no.3
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    • pp.254-259
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    • 1994
  • The ever increasing demand for energy and the shortage of resources all over the world have generated interest in recycling renewable sources such as lignocelluloses which otherwise would go to waste and cause environmental pollution. Lignin is the incrustation material for cellulose and hemicellulose, therefore, cellulose and hemicellulose are not easily degraded. Recycling lignocellulosic wastes as agricultural material are benefit to everybody and everything. In order to improve ligninase and laccase production of Phanerochaete chrysosporium, BKM-F-1767 and Ceriporiopsis subvermispora, FP 90031-SP, were compared. The ligninase activity of P. chrysosporium was maximum on day 4.5 of shaking culture at 150 rpm 2.5 cm in a back and forth cycle. The laccase activity of C. subvermispora was maximum on day 5.5 for 2% malt extract+0.1% yeast extract+0.1% Tween 20+6 mM Benzyl alcohol culture medium at stationary state.

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Occurrence of Synthetic Musk Compounds in Surface and Waste Waters in Korea (국내 하천수 및 하수처리장 유입.방류수의 합성머스크화합물 오염실태 조사)

  • Lee, In-Jung;Lee, Chul-Gu;Heo, Seong-Nam;Lee, Jae-Gwan
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.11
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    • pp.821-826
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    • 2011
  • Synthetic musk compounds are widely used as fragrances in a variety of personal care products like soaps, sampoos, cosmetics and perfumes. The occurrence of synthetic musk compounds in municipal sewage effluent and other environmental samples could negatively impact the health of the ecosystem and humans, due to persistent and long-term chronic exposure of aquatic organisms. Fifteen synthetic musk compounds (musk ketone, musk xylene, musk ambrette, musk moskene, musk tibetene, HHCB, AHTN, ADBI, AHDI, DPMI, ATII, ethylenebrasssylate, ambretettolide, cyclopentadecanolide, OTNE) were analysed in surface waters and sewage treatment plants (STP) influents/effluents in Korea by GC/MS. Method detection limits were $0.005{\sim}0.398{\mu}g/L$. HHCB and AHTN were most frequently observed in both surface waters and STP influents/effluents.

Evaluation of feed value of a by-product of pickled radish for ruminants: analyses of nutrient composition, storage stability, and in vitro ruminal fermentation

  • Jeon, Seoyoung;Sohn, Keun-Nam;Seo, Seongwon
    • Journal of Animal Science and Technology
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    • v.58 no.9
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    • pp.34.1-34.9
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    • 2016
  • Background: By-products of pickled radish (BPR) are considered food waste. Approximately 300 g/kg of the total mass of raw materials becomes BPR. Production of pickled radish has grown continuously and is presently about 40,000 metric tons annually in Korea. The objective of the present study was thus to explore the possibility of using BPR as a ruminant feed ingredient. Results: BPR contained a large amount of moisture (more than 800 g/kg) and ash, and comprised mostly sodium (103 g/kg DM) and chloride (142 g/kg DM). On a dry matter basis, the crude protein (CP) and ether extract (EE) levels in BPR were 75 g/kg and 7 g/kg, respectively. The total digestible nutrient (TDN) level was 527 g/kg and the major portion of digestible nutrients was carbohydrate; 88 % organic matter (OM) was carbohydrate and 65 % of total carbohydrate was soluble or degradable fiber. The coefficient of variation (CV) of nutrient contents among production batches ranged from 4.65 to 33.83 %. The smallest CV was observed in OM, and the largest, in EE. The variation in CP content was relatively small (10.11 %). The storage stability test revealed that storage of BPR at $20^{\circ}C$ (room temperature) might not cause spoilage for 4 d, and possibly longer. If BPR is refrigerated, spoilage can be deferred for 21 d and longer. The in vitro ruminal fermentation study showed that substitution of annual ryegrass straw with BPR improved ruminal fermentation, as evidenced by an increase in VFA concentration, DM degradability, and total gas production. Conclusion: The major portion of nutrients in BPR is soluble or degradable fiber that can be easily fermented in the rumen without adverse effects, to provide energy to ruminant animals. Although its high sodium chloride content needs to be considered when formulating a ration, BPR can be successfully used as a feed ingredient in a ruminant diet, particularly if it is one component of a total mixed ration.

Performance Evaluation of Web Image Server for sharing e-Commerce System's Image (전자 상거래의 이미지 공유를 위한 웹 이미지 서버의 성능 평가)

  • Kim, Myoung-Eun;Cho, Dong-Sub
    • The KIPS Transactions:PartB
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    • v.9B no.5
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    • pp.533-540
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    • 2002
  • We can buy products everywhere from Web-based shopping mall using desktop, cellular phone or PDA. To guarantee the various services for different equipment, shopping mail systems should allow a lot of different size or quality of images to provide a good service to their customers. Despite of same product image, each shopping mall saves the image in its storage space individually. Furthermore, all the product images in each shopping mall are stored as images of different quality. It may waste resources of shopping mail server and bring us developmental overhead. It is difficult to update all the images for product that is used by distributed e-catalog in everywhere. In this paper, we extended the proposed Web Image Server (WIS) for sharing one image with all clients and processing Image dynamically, so that we strengthened the function of managing shopping mall as a client of WIS and added the function of recording clients'log file and image catalog for shopping mall. We measured the response time from WIS and conventional e-Commerce site using by WAS which is one of the stress test tools for Web application. Furthermore, we measured WIS responses image requests in reasonable time when the current user is increased.

A Preliminary Design Concept of the HYPER System

  • Park, Won S.;Tae Y. Song;Lee, Byoung O.;Park, Chang K.
    • Nuclear Engineering and Technology
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    • v.34 no.1
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    • pp.42-59
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    • 2002
  • In order to transmute long-lived radioactive nuclides such as transuranics(TRU), Tc-99, and I- l29 in LWR spent fuel, a preliminary conceptual design study has been performed for the accelerator driven subcritical reactor system, called HYPER(Hybrid Power Extraction Reactor) The core has a hybrid neutron energy spectrum: fast and thermal neutrons for the transmutation of TRU and fission products, respectively. TRU is loaded into the HYPER core as a TRU-Zr metal form because a metal type fuel has very good compatibility with the pyre- chemical process which retains the self-protection of transuranics at all times. On the other hand, Tc-99 and I-129 are loaded as pure technetium metal and sodium iodide, respectively. Pb-Bi is chosen as a primary coolant because Pb-Bi can be a good spallation target and produce a very hard neutron energy spectrum. As a result, the HYPER system does not have any independent spallation target system. 9Cr-2WVTa is used as a window material because an advanced ferritic/martensitic steel is known to have a good performance under a highly corrosive and radiation environment. The support ratios of the HYPER system are about 4∼5 for TRU, Tc-99, and I-129. Therefore, a radiologically clean nuclear power, i.e. zero net production of TRU, Tc-99 and I-129 can be achieved by combining 4 ∼5 LWRs with one HYPER system. In addition, the HYPER system, having good proliferation resistance and high nuclear waste transmutation capability, is believed to provide a breakthrough to the spent fuel problems the nuclear industry is faced with.

Determinants of Sustainable Fashion Consumption in China - Based on the Theory of Planned Behavior - (중국소비자의 지속가능 패션 소비 결정요인 연구 - 계획된 행동이론을 중심으로 -)

  • HU, XINYU;Jeong, So Won;Kim, Eunhye;Lee, Jin-Hwa
    • Fashion & Textile Research Journal
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    • v.23 no.4
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    • pp.458-468
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    • 2021
  • In the context of Sustainable development, China, the world's second-largest apparel market, is also concerned about the environmental impact of fiber waste. Currently, there is a great interest in sustainable fashion in both supply and demand in China. Based on the theory of planned behavior(TPB), the determinants of sustainable fashion consumption(SFC) of Chinese consumers were evaluated in this study: man-nature orientation(MNO) and environmental knowledge(EK) as motivation and perceived online-store accessibility(POA) and perceived money availability(PMA) as barriers. Wenjuanxing, a Chinese professional survey collection agency, conducted an online survey of millennials in Shanghai, China. The final sample size for the survey was 215. Partial least squares structural equation modeling was employed to test the proposed hypotheses. The results indicated that attitudes, subjective norms, and perceived behavioral control significantly affected the purchase intention towards sustainable fashion products. MNO and EK influenced the attitude, whereas EK, POA, and PMA influenced perceived behavioral control. This study contributes to the TPB literature through the examination of four antecedents: MNO, EK, POA, and PMA. The findings provide valuable insights for retailers and markets based on the identification of the motivations and barriers that enhance the purchasing intention of Chinese millennials toward SFC.