• Title/Summary/Keyword: Air-foam

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Electrochemical Performances of Lithium-air Cell with Carbon Materials

  • Park, C.K.;Park, S.B.;Lee, S.Y.;Lee, H.;Jang, H.;Cho, W.I.
    • Bulletin of the Korean Chemical Society
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    • v.31 no.11
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    • pp.3221-3224
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    • 2010
  • This study investigates the requirements of lithium-air cathodes, which directly influence discharge capacity. The cathodes of Li-air cell are made by using five different carbon materials, such as Ketjen black EC600JD, Super P, Ketjen black EC300JD, Denka black, and Ensaco 250G. The Ketjen black EC600JD provides discharge capacity of 2600 mAh/g per carbon weight, while that of Ensaco 250G shows only 579 mAh/g. To figure out the differences of discharge capacity from carbon materials, their surface area and pore volume are analyzed. These are found out to be the critical factors in determining discharge capacity. Furthermore, carbon loading on Ni foam and amounts of electrolyte are significant factors that affect discharge capacity. In order to investigate catalyst effect, electrolytic manganese dioxide (EMD) is incorporated and delivered 4307 mAh/g per carbon weight. This infers that EMD facilitates to break $O_2$ interactions and leads to enhance discharge capacity.

Corrosion Protective Method Applicable to Air Vent Connected with a Heat Transport Pipe (열수송관에 연결된 에어벤트에 적용 가능한 부식 방지 방안)

  • Min Ji Song;Gahyun Choi;Woo Cheol Kim;Soo Yeol Lee
    • Corrosion Science and Technology
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    • v.22 no.2
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    • pp.115-122
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    • 2023
  • This study aimed to elucidate causes of corrosion of heat transport pipes and air vents installed under a manhole of heat transport facilities and suggest effective anticorrosive measures by applying paints or adhesive tapes. It was found that air vent corrosion was attributed to corrosion under insulation caused by the inflow of water and the enrichment of chloride ions. The infiltrated water caused a hydrolysis of polyurethane foam (PUF) insulation by concentrating chloride ions at the interface between a pipe and the PUF. As insulator deteriorated, more chloride ions were eluted as confirmed by ion chromatograph (IC) analysis. As an effective method to prevent air vent corrosion, different types of paints and adhesive tapes with higher corrosion resistance on chloride ions were applied and environmental resistance tests were performed with those samples. Based on environmental test results of samples exposed to 10% HCl solution, it was revealed that a wax tape was the most adequate from a viewpoint of stability at operating condition, environmental resistance, surface treatment, and field applicability.

A Suitable Thickness of Flexible Elastometic Foam (고무발포 보온재의 적정두께)

  • Yoon, Kwan-Sun;Lee, Gyo-Young
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.429-433
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    • 2008
  • Due to the construction technique (or the construction culture) growth in and out of Korea, newly-developed products have been continuously released. Furthermore, all legislation and regulation that the World follows are gradually becoming unified. (e.g. FTA(Free Trade Agreement) with the United States was contracted, and inevitable FTA contraction with EU and China), For this reason, it is considered that Korean fire regulation on building interior materials needs to be reviewed and compared with that of international standard so that it becomes legitimate and reasonable one.

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Mix Design and Characteristics of Compressive Strengths for Foam Concrete Associated with the Application of Bottom Ash (Bottom Ash를 사용한 기포콘크리트의 배합 설계 및 압축강도 특성)

  • Kim, Sang-Chel;Ahn, Sang-Ku
    • Journal of the Korea Concrete Institute
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    • v.21 no.3
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    • pp.283-290
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    • 2009
  • Differently from fly ash, the bottom ash produced from thermoelectric power plant has been treated as an industrial waste matter, and almost reclaimed a tract from the sea. If this waste material is applicable to foam concrete as an aggregate owing to its light-weight, however, it may be worthy of environmental preservation by recycling of waste material as well as reducing self-weight of high-rising structure and horizontal forces and deformations of retaining wall subject to soil pressure. This study has an objective of evaluating the effects of application of bottom ash on the mechanical properties of foam concrete. Thus, the ratio of bottom ash to cement was selected as a variable for experiment and the effect was measured in terms of unit weight of concrete, air content, water-cement ratio and compressive strength. It can be observed from experiments that the application ratios have different effects on the material parameters considered in this experiment, thus major relationships between application ratio and each material parameter were finally introduced. The result of this study can be applied to decide a mix design proportion of foam concrete while bottom ash is used as an aggregate of the concrete.

Explanation of Foaming Mechanism and Experimental Application of Foam Reduction Techniques in the Treated Wastewater Outlet of Wastewater Treatment Plant Connected to a Tidal River, Korea (감조하천에 연결된 하수처리장 방류구의 거품 형성기작 해석 및 거품발생 저감기술의 실험적 현장적용)

  • Shin, Jae-Ki;Cho, Youngsoo;Kim, Youngsung;Kang, Bok-Gyoo;Hwang, Soon-Jin
    • Korean Journal of Ecology and Environment
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    • v.49 no.3
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    • pp.187-196
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    • 2016
  • This study was performed to improve the foaming generated in the effluent of wastewater treatment plant from March 2015 to July 2016. The main cause of foaming was air entrainment by an impinging jet and the internal accumulation by the diffusion barrier. Particularly, the foam growth was most active when there is low tide and larger discharge. To solve this problem, we experimented after installing fine mesh screen and the artificial channel device with underwater discharging outlet in the treated wastewater discharge channel and the outlet, respectively. As a result, the effects of foam reduction by devices ranged 85.0~92.0% and 70.7~85.6%, respectively. In addition, the foam and the noise were easily solved, first of all look to contribute to the prevention of complaints. Our device studies were applied to a single wastewater treatment plant. However, it is considered to be able to apply in other similar cases of domestic sewage treatment plants.