• Title/Summary/Keyword: paste materials

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Geochemical Characteristics of Mine Wastes in Abandoned Mines in Korea (휴/폐광 광산폐기물의 지구화학적 특성)

  • 정명채;정영욱;민정식
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 1998.11a
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    • pp.71-75
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    • 1998
  • The objective of this study is to investigate geochemical characteristics of mine wastes including tailings in various abandoned mines in Korea. Tailings and wastes were sampled in and around 39 metalliferous mines, and analysed heavy metal concentrations including Cd, Cu, Pb and Zn extracted by 0.1N HCl and aqua regia by Atomic Absorption Spectrometry. Measurements of paste pH and lime requirement were carried out to examine a general geochemical characteristics of the materials. Lots of mine wastes were characterized by very low pH values of 2 to 4 and high lime requirement to control neutralization of the wastes. In addition, elevated levels of heavy metals were found in various mine wastes extracted by both 0.lN HCl and aqua regia. Because the mine wastes can be dispersed into the downstream by clastic movement and wind-blow, it is necessary to control the materials with a proper method for their reclamation.

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An experimental study on strength of hybrid mortar synthesis with epoxy resin, fly ash and quarry dust under mild condition

  • Sudheer, P.;Muni Reddy, M.G.;Adiseshu, S.
    • Advances in materials Research
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    • v.5 no.3
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    • pp.171-179
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    • 2016
  • Fusion and characterization of bisphenol-A diglycidyl ether based thermosetting polymer mortars containing an epoxy resin, Fly ash and Rock sand are presented here for the Experimental study. The specimens have been prepared by means of an innovative process, in mild conditions, of commercial epoxy resin, Fly ash and Rock sand based paste. In this way, thermosetting based hybrid mortars characterized by a different content of normalized Fly ash and Rock sand by a homogeneous dispersion of the resin have been obtained. Once hardened, these new composite materials show improved compressive strength and toughness in respect to both the Fly ash and the Rock sand pastes since the Resin provides a more cohesive microstructure, with a reduced amount of micro cracks. The micro structural characterization allows pointing out the presence of an Interfacial Transition Zone similar to that observed in cement based mortars. A correlation between micro-structural features and mechanical properties of the mortar has also been studied.

A study of dietetic on the constipation (변비(便秘)의 식료방법(食療方法)에 관한 연구(硏究))

  • Baek, Tae-Hyun
    • The Korea Journal of Herbology
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    • v.20 no.2
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    • pp.181-191
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    • 2005
  • Objectives : This research examined about dietary therapy on the constipation based on the literary findings, for clinical treatment and prevention of the constipation. Methods : This Research examined on histories, compositions, applications, and effects of the constipation on about 100 cases of dietary therapy of the constipation from recent Chinese literatures Results : 1. Various vegetables, animals and mineral materials including herbs, grains, vegetables, fruits, food and drink were used for the dietary therapy. 2. Methods of the preparation for use as therapeutics were decoction, pulvis, gruel, medicinal wine, cake, tea, paste and gelatin and etc. 3. Frequently used materials were sesame oil, honey, ear mushroom, shiitake mushroom, kelp, walnut seed, hemp seed, groundnut, glutinous rice, apricot stone, yellow bean peel, radish, potato, spinage, and spring onion. Conclusion : Though dietary therapy for the constipation is not based on clinical or experimental data, but through experience. It is mostly based on Yin-Yang and five elements, visceral manifestation, channels and their collateral channels and chinese herbal medicine theories. If we use them properly according to oriental medicine method, it will be effective on treating and preventing the constipation.

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실리콘 태양전지 후면 전계 형성 메카니즘 연구

  • Park, Seong-Eun;Song, Ju-Yong;Choe, Cheol-Jong;Tak, Seong-Ju;Kim, Hyeon-Ho;Kim, Seong-Tak;Gang, Min-Gu;Gwon, Sun-U;Yun, Se-Wang;Kim, Dong-Hwan
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2010.05a
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    • pp.38.2-38.2
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    • 2010
  • We have studied mechanisms of back contact formation in Al evaporation and screen printed Al paste for Si solar cells by TEM analysis. We observed that Si diffuse into Al during heat up. The Si diffusion process made vacancies in Si wafer. The Al began to seep into the Si wafer (Al spike). During heat down, the Al spike were shrink which causes the doped region (BSF).

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A Study on Form of Vessel for Traditional Fementation Storage Foods and that Materials-Concentrated on Soy Bean paste (전통발효 저장식품의 용기형태와 그 재료에 관한 연구)

  • 김홍산;권일현
    • Archives of design research
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    • v.14
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    • pp.233-243
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    • 1996
  • Our Country are called as a suzerain State of fermentation food, and preservative Technique was developed, because the specific character and the form of pottery were the best superior utensil of storage. The form couldn't give an explanation with scientifically, but we have used it for a few thousand years, which must get transformed from most compatible and reasonable form of fermentation. At present, a pottery was disappeared by the growth of the industrial society, and even the scientific form concealed it looks. For that reason, we apply the form into looks of a modernistic mechanism, and it intends to suggest a new direction to better the pottery of a formentation food.

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An Experimental Study on the Physical Properties Model of High Strength Concrete at High Temperature (고온시 고강도 콘크리트의 물리적 특성 모델 설정에 관한 실험적 연구)

  • Kim Heung-Yaul;Seo Chee-Ho;Choi Seng-Kwan;Jeon Hyun-Kyu
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05b
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    • pp.1-4
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    • 2005
  • This research is to present experimental materials model of high strength concrete for prediction of fire safety of structural members based on physical properties of materials during heating up to 800$^{circ}C$. The following conclusions are drawn from this study. First of all, between 100 to 200 $^{circ}C$, the physical models of concrete such as specific heat and thermal conductivity, show visible degradation, regardless of concrete strength. Second, between 300 to 600$^{circ}C$, the physical models of the 29MPa and 49MPa concrete show degradation continually at these temperatures. Finally, beyond 600$^{circ}C$, the physical models of 49MPa strength concrete show larger degradation than 29MPa strength concrete due to rise of pore pressure and melting of the interface between aggregate and cement paste.

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Evaluation on the Physical properties of Ultra Fine Cement for Grouting Materials (초미립자 시멘트의 지반 주입재로서의 특성 평가)

  • Park Won-Chun;Mun Kyoung-Ju;Jung Jong-Ju;Soh Yang-Seob
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.301-304
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    • 2004
  • The objective of this study is to evaluate the physical properties of ultra fine-ground cement for grouting materials. This study investigates the compressive strength of cement paste, homogenized gel and solidified soil matrix with ultra fine-ground cement. Also It is estimated the injection properties of ultra fine-ground cement. From the test results, the compressive strength of ultra fine-ground cement is higher than that of portland cement. The injection properties are sufficient to apply silt-sand soil and minute-cracked rock bed. Also the properties of soil stability like water permeability coefficient are enough to be adapted various grouting specification.

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A study of dietetic on the diarrhea (설사(泄瀉)의 식료방법(食療方法)에 관한 연구(硏究))

  • Baek, Tae-Hyeun
    • Journal of Pharmacopuncture
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    • v.9 no.2
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    • pp.155-166
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    • 2006
  • Objectives : This research examined about dietary therapy on the diarrhea based on the literary findings, for clinical treatment and prevention of the diarrhea. Methods : This Research examined on histories, compositions, applications, and effects of the diarrhea on about 100 cases of dietary therapy of the diarrhea from recent Chinese literatures Results : 1. Various vegetables, animals and mineral materials including herbs, grains, vegetables, fruits, food and drink were used for the dietary therapy. 2. Methods of the preparation for use as therapeutics were decoction, pulvis, gruel, medicinal wine, cake, tea, paste and gelatin and etc. 3. Frequently used materials were sesame oil, honey, ear mushroom, shiitake mushroom, kelp, walnut seed, hemp seed, groundnut, glutinous rice, apricot stone, yellow bean peel, radish, potato, spinage, and spring onion. Conclusion : Though dietary therapy for the diarrhea is not based on clinical or experimental data, but through experience. It is mostly based on Yin-Yang and five elements, visceral manifestation, channels and their collateral channels and chinese herbal medicine theories. If we use them properly according to oriental medicine method, it will be effective on treating and preventing the diarrhea.

Preparation of Ru-C Nano-composite Film by MOCVD and Electrode Properties for Oxygen Gas Sensor

  • Kimura, Teiichi;Goto, Takashi
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.358-359
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    • 2006
  • Ru-C nano-composite films were prepared by MOCVD, and their microstructures and their electrode properties for oxygen gas sensors were investigated. Deposited films contained Ru particles of 5-20 nm in diameter dispersed in amorphous C matrix. The AC conductivities associating to the interface charge transfer between Ru-C composite electrode and YSZ electrolyte were 100-1000 times higher than that of conventional paste-Pt electrodes. The emf values of the oxygen gas concentration cell constructed from the nano-composite electrodes and YSZ electrolyte showed the Nernstian theoretical values at low temperatures around 500 K. The response time of the concentration cell was 900 s at 500 K.

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Photo-imageable Thick-Film Lithography Technology for Embedded Passives Fabrication (내장형 수동소자의 제조를 위한 포토 이미징 후막리소그라피 기술)

  • Lim, Jong-Woo;Kim, Hyo-Tea;Kim, Jong-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.303-303
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    • 2007
  • Photo-imageable thick-film lithography technology was developed for the fabrication of embedded passives such as inductors and capacitors. In this study, photo-imageable dielectric and conductor pastes have apoted a negative type. Sodalime glass wafer, alumina substrate and zero-shrinkage LTCC green tapes were used as substrates. In result, The lithographic patterns were designed as lines and spaces for conductor material, or via-holes for ceramic, LTCC, materials. The scattering and reflection of UV-beam on the substrate had negative effects on fine patterning. The patterning performance was varied with the exposing and developing process conditions, and also varied with the substrate materials. Fine resolution of less then $50/50{\mu}m$ in line and space was obtained, which is difficult in screen printing method.

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