• Title/Summary/Keyword: green materials

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The Necessity Analysis of Development Waterproofing Materials and Methods of Construction Technologies for Green Roof (옥상녹화를 위한 방수재료 및 공법개발의 필요성에 관한 분석)

  • 권시원;오미현;강효진;오상근
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.05a
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    • pp.107-111
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    • 2003
  • The need for this study must be considerable, as being activate of green roofs research that the organization and construction obtain access to more development technologies. Nevertheless, the green roofs system has begun to apply since 1980's, the green roofs technology was restricted to develop without verification of technologies such as a load or water leakage. There is a limit as urethane waterproofing to almost domestic waterproofing materials and methods of construction for general green roofs. The introduction of materials and methods of construction which are appropriated to property of green roofs could be a decisive factor in a long-range durability and economical maintenance cost, moreover. it support to variety construction system and organization. This present paper describes a necessity of waterproofing and root barrier system is one of the sub-organization based on green roofs construction. which have enormously large impact on the durability.

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Effect of Polymeric Binders on Green body Properties of WC-Co Cemented Carbides (초경합금 성형체 특성 변화에 미치는 유기물 결합제의 영향)

  • Lim, Young-Soo;Ahn, Sun-Yong;Lim, Jae-Suk;Paek, Yeong-Kyeun;Chung, Tai-Joo
    • Journal of Powder Materials
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    • v.29 no.4
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    • pp.291-296
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    • 2022
  • The green body of WC-Co cemented carbides containing polymeric binders such as paraffin, polyethylene glycol (PEG), and polyvinyl acetate (PVA) are prepared. The green density of the WC-Co cemented carbides increases with the addition of binders, with the exception of PVA, which is known to be a polar polymeric substance. The green strength of the WC-Co cemented carbides improves with the addition of paraffin and a mixture of PEG400 and PEG4000. In contrast, the green strength of the WC-Co does not increase when PEG400 and PEG4000 is added individually. The compressive strength of the green body increases to 14 MPa, and the machinability of the green body improves when more than 4-6 wt% paraffin and a mixture of PEG400 and PEG4000 is used. Simultaneously, the sintered density of WC-Co is as high as 99% relative density, similar to a low binder addition of 1-2 wt%.

Characteristics of an MgO Green Sheet as a Protective Layer of AC-PDP

  • Park, Deok-Hai;Park, Min-Soo;Kim, Bo-Hyun;Ryu, Byung-Gil;Kim, Sung-Tae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.387-390
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    • 2006
  • The protective layer of AC-PDP was fabricated by laminating an MgO green sheet. The MgO green sheet was made by coating MgO solution composed of solvent, dispersant, binder, and MgO nano-powder. The MgO solution was coated by the die casting method on the base film. We fabricated three kinds of MgO green sheets of which thicknesses were 20, 28, and $40\;{\mu}m$, respectively. The MgO nano-powder showed lower CL intensity and ${\gamma}i$ than the e-beam MgO. The MgO green sheet applied panels showed low luminance and current density. The efficiency was almost same as the conventional e-beam MgO panel.

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Formaldehyde Adsorption and Physical Characteristics of Hydrothermal Reacted Panels Using Porous Materials (다공성 원료를 사용한 수열합성 패널의 물성과 포름알데히드 흡착 특성)

  • Im, Du-Hyuk;Chu, Yong-Sik;Song, Hoon;Lee, Jong-Kyu
    • Journal of the Korean Ceramic Society
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    • v.46 no.6
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    • pp.627-632
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    • 2009
  • Formaldehyde emissions from the construct was harmful to human. Diatomite, bentonite and zeolite were used as porous materials for fabricating panels. Formaldehyde adsorption and physical characteristics of porous materials were investigated and hydrothermal method was applied to fabricate panels. Formaldehyde adsorption contents of panels with porous materials were higher than that of panel without porous materials. The panels with Cheolwon diatomite and Pohang zeolite showed excellent characteristics of Formaldehyde adsorption. These characteristics were caused by higher surface area and pore volume of porous materials. Formaldehyde adsorption contents were influenced by surface area and pore volume of panels. Correlation coefficient between surface area and Formaldehyde adsorption content of panels was 0.87. The panels with porous materials had higher strength than that without porous materials because of bridging role particles.

Properties of the Green Gold Alloys with Indium Content

  • Song, Jeongho;Song, Ohsung
    • Korean Journal of Materials Research
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    • v.28 no.4
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    • pp.221-226
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    • 2018
  • The property changes of 18, 14, and 8K green gold alloys for jewelry are observed by adding 0.0, 3.0, and 5.0 wt% of indium (In), respectively. To check the composition of the alloys, an energy dispersive spectroscopy (EDS) analysis is conducted. Color and microstructure analysis is executed through bare-eye, macro camera, UV-VIS-NIR-colormeter, and optical microscope. The melting point, wetting angle, and hardness are measured using TGA-DTA, a wetting angle tester, and a Vickers hardness tester. The EDS analysis result demonstrates that each of the green gold alloys was manufactured with purposed contents. The color analysis result shows that the color of the alloys is similar to the color of the conventional 4 wt%-Cd 18K green gold, and the green color improves as the In content increases. The micro structure analysis result demonstrates that grain refinement improves as the amount of In increases. Enhancements in the melting point, wettability, and Vickers hardness changes appear as the In content increases and Au content decreases. The hardness is up to 260, which implies good durability. Therefore, the results suggest that the proposed 18, 14, and 8K In-added green gold alloys enhance the properties of jewelry products with regard to the green color, castability, and durability.

Processing of Functionally Graded Materials via Green Tape Lamination

  • Cho, Yu-Jeong;Kim, Yong-Seog
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2003.10a
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    • pp.78-79
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    • 2003
  • A functionally graded material was produced by laminating green tapes. The lamination resulted in the formation of functionally graded structure and sintering of the materials resulted of FGM. This results demonstrated a possibility of using green tapes in the processing of functionally graded materials.

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A Study on information structure of materials for green design -Based on the CSI MasterFormat- (그린 디자인을 위한 재료 정보 구조에 관한 연구)

  • 이현수;김은영
    • Korean Institute of Interior Design Journal
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    • no.25
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    • pp.290-294
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    • 2000
  • Between multiple components of the building, materials have a direct impact on the environment. For many researchers have proposed guidelines for green design materials. However they didnt provide concrete criteria for selecting materials for selecting materials for achieving green design. From the perspective of this point, this paper proposes. Performance information expressed numerically is the most important factor. The purpose of this study is to provide the specific information about the performance of materials that has been ranked quantitatively. The performance information can be utilited in selecting materials for green design.

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Influence of Graphite Epoxy Composite Material on the Electrochemical Galvanic Corrosion of Metals (금속재료의 전기화학적 갈바닉 부식에 미치는 GECM의 영향)

  • Yoo, Y.R.;Son, Y.I.;Shim, G.T.;Kwon, Y.H.;Kim, Y.S.
    • Corrosion Science and Technology
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    • v.8 no.1
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    • pp.27-39
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    • 2009
  • Non metallic composite materials, for example, GECM(graphite epoxy composite material) show high specific strength because of low density. These kinds of non metallic composite materials improved the structural effectiveness and operation economics. However, if these materials contacted several metals, corrosion can be arisen since non metallic composite materials have electrical conductivity. This paper dealt with galvanic corrosion between graphite epoxy composite material and several metals. Base on the electrochemical galvanic corrosion test between GECM and metals, corrosion current of carbon steel and aluminium increased with time but corrosion current of stainless steels and titanium decreased and galvanic potential increased. This behavior shows the galvanic corrosion depends upon the presence of passive film. Also, galvanic effect of GECM coupled with ferrous alloys and non-ferrous alloys was lower than that of 100% graphite, which is attributed to lower exposed area of graphite fiber in the GECM than apparent area of the GECM specimen used for the calculation of galvanic current in this work.

THE AMOUT OF LOSS AND THE DEGREE OF SURFACE SMOOTHNESS OF GOLD ALLOY BY GOLD ALLOY POLISHING RUBBER POINT MATERIALS (금합금 연마재 종류에 따른 금합금 소실량과 연마 정도)

  • Kim, Myoung-Hwa;Yim, Soon-Ho;Chung, Moon-Kyu
    • The Journal of Korean Academy of Prosthodontics
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    • v.35 no.2
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    • pp.277-295
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    • 1997
  • After clinical adjustment of dental casting restoration, re-polishing procedure is recommanded because the smooth gold sureface is lost. But there is the possibility to get more loose contact than that intended by loss of gold alloy according to the kinds of polishing materials and polishing time. Therefore in this study I polished type II gold alloy with 390gm force, 20,000rpm speed, and 8 kinds of gold alloy polishing materials, fabricated by 4 companies and then measured the amount of loss of gold alloy with Surfcorder SEF-30D and observed alloy surfaces polished by 3 brown rubber points with SEM. The amount of loss of gold alloys polished with 8 kinds of polishing materials and the degree of smoothness of gold alloys according to polishing time and polishing materials were compared. The following results were obtained : 1. When the amount of loss of gold alloys polished with 3 kinds of brown rubber point was compared, Alphalex brown point had the most amount of alloy loss, followed in decreasing order by Shofu brown point and Eveflex brown point. There was statistically significant difference in the amount of alloy loss according to polishing materials. 2. When the amount of loss of gold alloys polished with 5 kinds of green rubber point was compared, Shofu green point had the most amount of alloy loss, followed in decreasing order by Alphaflex green point, Dedeco green clasp polisher, and Eveflex green point. There was statistically significant difference in the amount of alloy loss according to polishing materials except Alphaflex green point and Dedeco green clasp polisher. 3. When the amount of loss of gold alloys polished with all kinds of rubber point was compared, there was no significant difference in Eveflex brown point, Alphaflex green point, and Dedeco green clasp polisher. 4. When average amount of alloy loss per 1 revolution by polishing materials was compared, Alphalex brown point had the greatest value as $0.329{\mu}m$ and Shofu supergreen point had the lowest value as $0.022{\mu}m$. 5. When the degree of sureface smoothness of gold alloy polished with 3 kinds of brown rubber point was compared, In Alphalex brown point surface roughness was completely lost after 20 seconds polishing time, in Shofu brown point 30 seconds, in Eveflex brown point 40 seconds. But in every gold alloys fine scratch formed by rubber points was observed. Based on the results of this study, as rubber polishing materials used in polishing of dental casting restoration after clinical adjustment influenced on the tightness of occlusal or proximal contact, we should make dental casting restoration with minimum error through careful laboratory procedure and form very smooth surface of restoration with tripoli and rouge after use of silicone polishing materials.

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