• Title/Summary/Keyword: green materials

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Effect of Cu Addition on the Properties of Duplex Stainless Steels

  • Hwangbo, D.;Yoo, Y.R.;Choi, S.H.;Choi, S.J.;Kim, Y.S.
    • Corrosion Science and Technology
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    • v.21 no.4
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    • pp.273-281
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    • 2022
  • The effect of addition of Cu on the localized corrosion performance of aged duplex stainless steel in chloride media has yet to be explained in a consistent manner, and there is some controversy in the literature regarding the composition of stainless steel and the experimental conditions (pH, temperature, chloride concentration, etc.) used. In this work, the effect of the addition of Cu on the microstructure, hardness, and corrosion resistance of duplex stainless steel in an acidic chloride or high concentration sulfuric acid solutions was investigated for annealed and aged alloys. The Cu addition of annealed duplex stainless steel strengthened the alloy and reduced the ferrite contents of the alloy, and it also increased the polarization behavior in chloride or sulfuric solutions, except for the case of a high potential in acidic chloride solution. However, the Cu addition of aged duplex stainless steel reduced the formation of harmful phases such as sigma and kai and increased the polarization behavior in acidic chloride or sulfuric solutions up to 0.8 wt% of the Cu content, after which it slightly decreased at 0.8 wt% Cu or more.

Contribution to Green Power Technology Through Electrical Insulating Materials Research

  • Ohki, Yoshimichi
    • Transactions on Electrical and Electronic Materials
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    • v.11 no.4
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    • pp.149-154
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    • 2010
  • With soaring public concerns of environmental issues, many researchers have started to carry out research on various related topics in many areas of science and engineering. This paper describes a brief outline of typical recent research results obtained in the author's laboratory on electrical and optical properties of dielectric materials, done aiming at contributing to green power technology.

Study for Level of Evidence and Recommendation of Anticancer Effect for the Materials of Green Vegetable Juice by Using Natural Standard Methodology (Natural Standard Methodology를 이용한 녹즙재료의 항암효과에 대한 근거 및 권고수준에 대한 연구)

  • Yoo, Hwa-Seung
    • Journal of Haehwa Medicine
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    • v.17 no.1
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    • pp.11-19
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    • 2008
  • Objective : We designed this study to analyse the anti-cancer effects of materials of green vegetable juice by using the natural standard methodology and apply the results to new studying and evaluating methods. Methods : We investigated the main stream of complementary and alternative medicine (CAM), the methodology of natural standard, guideline in CAM, and concrete 15 green vegetable juice in cancer therapy. Results : There are 15 graded materials of green vegetable juice that associated with cancer in natural standard contents. Most of them get grade C, unclear or conflicting scientific evidence. Conclusion : Natural Standard aims to provide high-quality, reliable information about CAM therapies to clinicians, patients, and healthcare institutions. We have to acquire more reliable evidence in future.

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Content Analyses of Green Life-Teaching Materials in Korean and Japanese High School Home Economics Textbooks (한.일 고등학교 가정교과서 녹색생활 학습자료 분석)

  • Cho, Jae-Soon;Park, Mi-Jeong;Jang, Sang-Ock;Lee, Yon-Suk
    • Journal of Korean Home Economics Education Association
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    • v.23 no.1
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    • pp.19-36
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    • 2011
  • The purpose of this paper was to explore the teaching materials in the Korean and Japanese high school Home Economics textbooks from the perspective of green life education. Although sustainable living at home has been emphasized as one of the main issues of Home Economics since the first curriculum period, green growth education has reinforced in the 2009 revised curriculum. The content analyses had been done to explore the teaching materials of five areas in the 6 Korean and 4 Japanese high school Home Economics textbooks through two checking steps. The material form of table-figure-pictures was the most frequently shown in both Korean and Japanese textbooks. Green life-teaching materials were more likely in the area of household management/consumer activity than in any other ones. All textbooks of both countries have included the green life-teaching materials according to the elements of contents mentioned in the curricula. The quantity and contents of the materials were some what differ by textbooks, so home economics teacher need to cross check the all textbooks to select useful information although the textbooks have included various types of green materials over the 5 areas. Home Economics curriculum need to actively and concretely include the green growth educational elements suggested by the previous study.

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Approaching Green Buildings Using Eco-Efficient Construction Materials: A Review of the state-of-the-art

  • Aghdam, Karim Aligholizadeh;Rad, Alireza Foroughi;Shakeri, Hamed;Sardroud, Javad Majrouhi
    • Journal of Construction Engineering and Project Management
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    • v.8 no.3
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    • pp.1-23
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    • 2018
  • Since the protection the of human being from natural disaster and atmospheric factors have become an essential requirement, some attempts have been taken place to provide shelter and create a safe environment to a more comfortable life with welfare. For this purpose, using existing resources in nature and exploiting them in a different manner have been taken into account. Initially, the performed exploitations for construction had the least damage to the environment, but over time and as a result of population growth, aggressive exploitation of nature has led to destroying effects on the environment and resulted in consequences such as pollution and environmental destruction. Thus, the construction industry has been identified as the top pollutant factors of the environment. Among various construction factors, the building materials used in this industry are considered as the most important effective factors on the environment, as they have direct influences on the environment from the beginning of construction of the final steps. This research focuses on the review of the most of the existing green materials definitions and various approaches towards using eco-efficient construction materials. It presents and discusses possible ways of reducing the destructive effects on the environment by selecting and using green materials, review current literature and highlight the necessity of applying such materials in future constructions in all communities. This paper provides a base for this purpose that sustainable development communities and environment is realized by elimination of environmental pollution and approaching the criteria of green building by using sustainable materials.

Preparation and Luminescence Properties of PDP Green Phosphors using Polymer Matrix Technique

  • Jun, Sang-Bae;Lee, Dong-Kyu;Kim, Soo-Jong;Masaki, Takaki;Han, Chung-Hwa
    • Transactions on Electrical and Electronic Materials
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    • v.8 no.3
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    • pp.121-124
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    • 2007
  • The $Zn_2SiO_4:Mn$ phosphors were prepared using polymer matrix technique in order to improve the performance of green emitting phosphors for plasma display panel(PDP). $Zn_2SiO_4:Mn$ phosphor exhibits a strong green emission around 520-530 nm. The emission intensity and particle size of powders were controlled by sintering temperature and raw material composition. The zinc silicate $Zn_2SiO_4:Mn$ single phase were obtained at lower temperature than prepared by solid-state reaction method. PL luminance of $Zn_2SiO_4:Mn$ phosphor was similar to the commercial material.

Early Stage Growth Structure and Stress Relaxation of CoCrPt Thin Films on Spherically Modulated Polymer Surface

  • Kim, Sa-Rah;Jeong, Jun-Ho;Shin, Sung-Chul;Son, Vo Thanh;Jeon, Bo-Geon;Kim, Cheol-Gi;Jeong, Jong-Ryul
    • Journal of Magnetics
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    • v.15 no.1
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    • pp.12-16
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    • 2010
  • Combined study of in-situ stress measurements and atomic force microscopy (AFM) revealed drastic stress relaxation in the CoCrPt and PS(styrene)-PVP(vinyl pyridine) polymer hybrid structure that was closely related to the growth structure of the film. We have observed not only no large initial growth stress at the initial stages of film growth but also twice smaller stress in magnitude with opposite sign in the CoCrPt/PS-PVP/Si sample. The microstructural studies using AFM at the various film growth stages revealed that the film growth structure plays an important role in the stress relaxation mechanism of CoCrPt films on a corrugated polymer surface.

Present Status of Green Solvents (녹색용매 기술동향)

  • Lee, Jun-Wung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.4
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    • pp.475-491
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    • 2012
  • Green Chemistry emerged at the end of 20th century, which aims the development of the technologies for the sustainable society at the molecular level. Most products we consume in everyday life are produced through chemical processes, and we often oversee the fact that huge amount of solvents are used and disposed. At the present time most solvents used in laboratories as well as industries are volatile organic compounds(VOC), which gives health and environmental problems. Therefore scientists are seeking new materials which have equivalent properties of VOCs as solvent, and at the same time gives no health and environmental problems. In this brief review, the author describes the present status of research and development activities of green solvent materials throughout research societies worldwide. At present the most attractive green solvent candidates are water, glycerol, supercritical carbon dioxide and ionic liquids. In order to give the pictures of these materials, the author tried to introduce the overall aspects of green solvents in various chemical reaction as well as catalytic roles.