• Title, Summary, Keyword: Recyclable

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Recycling Properties of Visible-Light Driven CdZnS/ZnO Photocatalyst Prepared by a Simple Precipitation Method (단순 침전법으로 제조한 가시광선용 CdZnS/ZnO 광촉매의 재활용 특성)

  • Lee, Gun Dae;Park, Seong Soo;Jin, Youngeup;Hong, Seong Soo
    • Clean Technology
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    • v.23 no.2
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    • pp.196-204
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    • 2017
  • CdZnS/ZnO composite was prepared through low-temperature precipitation and drying method. The property of CdZnS/ZnO as a recyclable photocatalyst for the degradation of rhodamine B (RhB) under visible light irradiation was examined. The sample was characterized by XRD, FE-SEM, XPS, UV-vis DRS and photoluminescence techniques before and after repeated reaction to investigate the change of properties during the photocatalytic reaction. During repeated reaction, the CdZnS/ZnO showed an improved photocatalytic activity and recycle stability. Among two feasible reaction pathways for photocatalytic degradation of RhB, the cleavage of conjugated chromophore was found to predominate over N-dealkylation of chromophore skeleton in the present work. The results indicate that the CdZnS/ZnO, prepared by a simple precipitation method, can be used as a visible-light driven photocatalyst with enhanced cycle stability and activity.

Alteration in Leukocyte Subsets and Expressions of FcγR and Complement Receptors among Female Ragpickers in Eastern India

  • Mondal, Nandan K.;Siddique, Shabana;Banerjee, Madhuchanda;Roychoudhury, Sanghita;Mukherjee, Sayali;Slaughter, Mark S.;Lahiri, Twisha;Ray, Manas R.
    • Safety and Health at Work
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    • v.8 no.2
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    • pp.198-205
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    • 2017
  • Background: There are a million ragpickers in India who gather and trade recyclable municipal solid wastes materials for a living. The objective of this study was to examine whether their occupation adversely affects their immunity. Methods: Seventy-four women ragpickers (median age, 30 years) and 65 age-matched control housemaids were enrolled. Flow cytometry was used to measure leukocyte subsets, and leukocyte expressions of $Fc{\gamma}$ receptor I (CD64), $Fc{\gamma}RIII$ (CD16), complement receptor 1 (CD35) and CR3 (CD11b/CD18), and CD14. Serum total immunoglobulin-E was estimated with enzyme-linked immunosorbent assay. Results: Compared with the controls, ragpickers had significantly (p < 0.0001) higher levels of CD8-T-cytotoxic, CD16+CD56+natural killer, and CD4+CD45RO+memory T-cells, but depleted levels of CD19+B-cells. The percentage of CD4+T-helper-cells was lower than the control group (p < 0.0001), but their absolute number was relatively unchanged (p = 0.42) due to 11% higher lymphocyte counts in ragpickers. In ragpickers, the percentages of CD14+CD16+intermediate and CD14dim CD16+nonclassical monocyte subsets were elevated with a decline in CD14+CD16-classical monocytes. The expressions of CD64, CD16, CD35, and CD11b/CD18 on both monocytes and neutrophils, and CD14 on monocytes were significantly higher in ragpickers. In addition, ragpickers had 2.7-times more serum immunoglobulin-E than the controls (p < 0.0001). After controlling potential confounders, the profession of ragpicking was positively associated with the changes. Conclusion: Ragpicking is associated with alterations in both innate (neutrophils, monocytes, and natural killer cell numbers and expression of complement and $Fc{\gamma}$ receptors) and adaptive immunity (numbers of circulating B cells, helper, cytotoxic, and memory T cells).

Environmental Assessment and Characteristic of Refuse Derived Fuel by Mixed Biomass with Binder (바이오매스에 바인더 첨가에 따른 폐기물 고형연료 특성 및 환경성평가)

  • Lee, Hyung-Don;Cho, Joon-Hyung;Kim, In-Deuk;Kim, Yun-Soo;Oh, Kwang-Joong
    • Clean Technology
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    • v.17 no.4
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    • pp.336-345
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    • 2011
  • The total area of forest land in Korea is 64.2%, and significant forest resources can continuously be produced. However our country didn't separate the recyclable waste wood and was illegal landfill or incinerated. In this study, waste-wood and rice husk of biomass and low-grade-anthracite made refuse derived fuel by mixing and compressing. In addition, the binding effect of binders and additives were analyzed. Physical and chemical characteristics of manufactured refuse derived fuel were analyzed and evaluated suitability by compared with quality standards. A result of change with compressed and relaxed density, added 20% anthracite and 10% rice husk is optimal density change and average density increased large range when 20 wt.% P.V.A., guargum, molasses and 10 wt.% starch were added. All fuel samples be distributed over 3,500 kcal/kg LHV and grade of No. 3~4 fuels appeared. A result of the characteristics of physical and chemical compressed biomass refuse derived fuel with addictive, 12.9% of durability improvement appeared when is mixing asphalt and 5.8% of durability improvement appeared when is mixing rice bran by pretreatment of NaOH 5%.

Feasibility Evaluation of Co-Incineration with MSW for Efficient Recycling of the Rejects after Separation Processes in MRF (재활용 기반시설에서 발생하는 선별 잔재물의 자원화를 위한 도시생활폐기물과의 혼합소각 가능성 평가)

  • Shin, Taek-Soo;Sung, Baek-Nam;Yeon, Ik-Jun;Cho, Byung-Yeol;Kim, Kwang-Yul
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.10
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    • pp.767-773
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    • 2011
  • The purpose of this study was to investigate the possibility of an alternative fuel resource by incinerating a mix of combustible MSW (municipal solid waste) and offals after separating recyclable material at the MRF (material recovery facilities) location. We analyzed the physical and chemical properties including the 3-contents, the calorific value, and chemical compositions of the separation rejects in MRF, and compared the results with combustible MSW. Moreover, we experimented the trend of combustible properties and the concentration change of air pollutants at mixed incineration in the MSW incinerator. According to the results of the experiment, the separation rejects showed higher heating value (5,865 kcal/kg), and lower moisture and ash content than combustible MSW. Since we have incinerated MSW in the MSW incinerator mixing the offals at 30% and 50% respectively, we know that the change of the concentration of dust, $SO_2$, $NO_2$, and CO did not appear significant, and not exceed the pollutants emission regulation. But, considering the enhancement of the HCl emission concentration (max. 33.7 ppm) at the co-incineration of the 50% offals, we believe that the proper mixing ratio of the separation rejects would become within 30%.

Preparation and Properties of UV Curable Phlorogulcinol Based Acrylate for PET Film (PET 필름용 UV 경화 플로로글루시놀계 아크릴레이트 제조 및 물성)

  • Choi, Jeon-Mo;Lee, Eun-Young;Kim, Sangyong;Cho, Jin-Ku;Kim, Baekjin;Lee, Sang-Hyeup;Kim, Hyun Joong
    • Journal of Adhesion and Interface
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    • v.11 no.2
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    • pp.50-56
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    • 2010
  • Polyethyleneterephthalate (PET) film is widely used in various industrial fields such as mobile phone, display pannel, notebook etc. Recently PET film attached on indium tin oxide (ITO) surface has a role of high pencil hardness, high refractive index etc. So we synthesized two types of multi-functional monomer which are epoxy modifed acrylate and unmodified acrylate type using recyclable resource like phloroglucinol, derived from trinitrotoluene. We studied the effect of multi-functional monomer's chemical structure on the various properties such as refractive index, optical transmittance, and pencil hardness. We characterized synthesized multi-functional monomer by qualitative analysis through H NMR. We observed that pencil hardness of 1,3,5-triepoxide benzene and 1,3,5-triacrylate benzene they have the range of 2~3 H at high UV dosage of 300 mW. Refractive index appeared the value of 1.54~1.57. Transmittance of all multi-functional monomers has more than 93%.

Developing a Study on the Extracting Method of Laminated Glass Fiber from FRP Boats (폐FRP 선박으로부터 섬유보강재 추출공정 개선 연구)

  • Yoon, Koo-Young
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.12 no.1
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    • pp.23-28
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    • 2009
  • There is several ways of recycling methods for waste FRP boats. The main one is mechanical recycling that is one of the simple and technically proven methods. It recently has been reported that FRP can be recycled by separating into laminated glass fiber layers instead of crushing into powder. Even though the mechanical recycling is a good way for the eligibility of laminated glass fiber reinforced material, the system should have another option which can collect resin of FRP. Because the resin is still very useful renewable energy source, that cannot be discarded, But FRP is made up of laminated glass fiber(roving cloth layer) which is fire retardant substances and very hard to break into each layer. Due to the high cost of fossil energy the waste plastics should be regenerated to the source of renewable energy. Laminated glass fiber which is recyclable in a very limited way, is currently a serious barrier to waste FRP boat regenerating. This study is to propose a new extracting method which is efficient and environment friendly FRP waste regenerating system. The recycled glass fiber which is obtained by the separation of the roving layer from FRP waste has been found to be useful for concrete(FRC) products or concrete(FRC) structures as fiber reinforced material. And it can be successively applied to renewable energy applications using the waste resins of FRP residue without laminated glass fiber.

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Development of Separation System with Rotating Rakes for Recovery of Film-based Plastics (기계식(機械式) 회전(回轉)레이크를 이용(利用)한 생활계(生活界) 폐기물(廢棄物) 필름류(類) 선별장치(選別裝置) 개발(開發)에 관(關)한 연구(硏究))

  • Lee, Byung-Sun;Na, Kyung-Duk;Han, Sang-Kuk;Choi, Woo-Zin;Park, Eun-Kyu
    • Journal of the Korean Institute of Resources Recycling
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    • v.19 no.3
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    • pp.24-32
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    • 2010
  • In the present work, a new separation system with rotating rakes has been developed to separate the film-based plastics from the recyclable materials, and environment assessment is also carried out during operation of the device. Capacity of the device was about 5.3 ton/hr at a rakes rotation speed of 26.0 rpm (the number of rakes in the 1st, 2nd and 3rd trials were 39, 52 and 48, respectively) and a belt conveyor speed of 38.5m/min, which satisfied the initial design capacity (5.0 ton/hr). Recovery ratio and purity of the plastic films were 92.6% and 96.5%, respectively at a rotation speed of 28 rpm. The levels of noise, vibration and particulate emission were below material standard regulatory limits. Plastic refused fuel (RPF) was also prepared with the recovered films. The calorific value and chlorine content of the prepared RPF were 9,740 kcal/kg and 0.18%, respectively which satisfy the first grade quality specification of the Korean RPF standard. As a result of this work, recovery of energy resources from the municipal solid waste is possible by adopting the developed separation device.

Development of Bag Rupturing Device with Octagonal Rotating Blade Drums for MSWs (생활계(生活系) 폐기물(廢棄物) 봉투(封套) 파봉을 위한 회전(回傳)칼날팔각(八角)드럼식(式) 파봉장치(裝置) 개발(開發)에 관(關)한 연구(硏究))

  • Lee, Byung-Sun;Na, Kyung-Duk;Han, Sang-Kuk;Choi, Woo-Zin;Park, Eun-Kyu;Kim, Dong-Ho
    • Journal of the Korean Institute of Resources Recycling
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    • v.18 no.5
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    • pp.63-71
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    • 2009
  • Recyclable wastes coming into material recovery facilities(MRFs) is mostly packed by plastic bag or sack bag. Bag rupturing device is essential to improve capacity and efficiency of MRFs. Bag opening works of MRFs is mostly done by numerous workers and shredder-type bag rupturing device. It often makes a problems; decreased capacity, shredded recyclables, worker safety by explosion and broken glasses, etc. In the present work, bag rupturing device with octagonal rotating blade drums has been developed to solve the existing problems and environment assessment is also performed during operation of the device. Capacity of the device was about 5.6 ton/hr at 8.2 rpm of drum revolution speed and 1.25 m/min of belt conveyor speed. It satisfied initial designed capacity(5.0 ton/hr) and max. capacity 8.8 ton/hr was achieved at 12.5 rpm of drum revolution speed and 1.50m/min of belt conveyor speed. Bag rupturing efficiencies on outer and inner bag were obtained at 100% and about 95.6% as average, respectively and original form of glass bottles in the bag was maintained without broken by about 96.5%. This result shows that the safety in hand sorting by the workers could be improved. As result of environmental assessment on the noise, vibration and particulates, the measured levels on noise, vibration and particulates show the below standard regulatory limits. It could be concluded that the problems of existing devices in MRFs could be solved by adopting the bag rupturing device with octagonal rotating blade drums in on-site operation.

A Study on the Flow Characteristics around Tidal Current Turbine (조류발전용 터빈 주위의 유동 특성에 관한 연구)

  • Kim, Bu-Gi;Yang, Chang-Jo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.6
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    • pp.610-616
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    • 2012
  • All the countries in the world is currently facing the full scale of energy-climate era currently, and making strong energy policy that will lead to green growth of the future energy resources by utilizing renewable energy as the basis of entering the advanced country becomes the goal of development that satisfies the demand for energy in 21st century. Recently, ocean energy attracted the attention along with the necessity of developing renewable energy. Ocean energy is the one of most prominent recyclable and clean resources that has not been developed yet. So, it is highly required to develop good tidal current energy conversion system in coastal area. The inflow angle that acts against tidal current turbine, seabed effect and the change of efficiency along the occurrence of cavitation were investigated through the wake flow characteristics in this study. Power coefficient degradation by seabed effect did not appear in the condition of this calculation. Efficiency degradation appeared from above $10^{\circ}$ regarding inflow angle and power coefficient was calculated as lower by 7 % at $45^{\circ}$. Torque and power coefficient increased as inflow velocity rose, but power coefficient degradation appeared from above 3m/s when the cavitation happened. So, it was recognized that the larger inflow angle and occurrence of cavitation become the reason for power degradation through the flow characteristics.

Critical Success Factors for Wind Power Projects (풍력 발전소 프로젝트의 핵심성공요인)

  • Lyou, An-Suck;Kim, Byung-Il;Kim, Hyoung-Kwan
    • Korean Journal of Construction Engineering and Management
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    • v.13 no.1
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    • pp.140-147
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    • 2012
  • Climate changes caused by fossil fuel energy usages have led to serious environmental damages and resource scarcity. Ever-increasing demand for energy causes harsh competition in international energy markets. Nuclear power, which once was regarded as a desirable clean energy, began to face public oppositions after the Japanese nuclear disaster in 2011. In this context, wind power is now considered to be an ever-more important recyclable energy source. Thus, this study intended to identify critical success factors for wind power construction projects. After a thorough literature review, two focus group interview sessions were conducted. A questionnaire-based survey, coupled with the two previous methods, resulted in the extraction of important factors for the success of wind power projects. Experts, including those working as constructors, designers, and owners, were paid a direct visit for the interview and survey. The critical success factors were categorized into feasibility study, right policies, equipment selection, and project financing issues. The proposed critical success factors are expected to be an effective guideline for future investors in wind powers.