• Title/Summary/Keyword: Green-one

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An analytical study on unsteady thermal stresses of functionally graded materials (경사기능재료의 비정상 열응력에 관한 해석적 연구)

  • Choi, Deok-Kee;Kim, Chang-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.9
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    • pp.1441-1451
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    • 1997
  • This paper addresses method which can be used for analyzing thermal stresses of a functionally graded material(FGM) using semi-analytical approach. FGM is a nonhomogeneous material whose composition changes continuously from a metal surface to a ceramic surface. An infinite one dimensional FGM plate is considered. The temperature distribution in the FGM is obtained by approximate Green's function solution. To expedite the convergence of the solutions, alternative Green's function solution is derived and shows good agreement with results from finite difference method. Thermal stresses are calculated using temperature distribution of the plate.

METHODS OF UREA INCORPORATION IN STRAW AND THEIR EFFECTS ON PERFORMANCE OF BUFFALO HEIFERS

  • Akbar, M.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.5 no.3
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    • pp.545-548
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    • 1992
  • Twelve indigenous buffalo heifers were grouped into 3 and were supplied with following diets-urea-ensiled rice straw + wheat bran + green grass (A); rice straw soaked in urea-water + wheat bran + green grass (B); and untreated straw + wheat bran + green grass (C); so that each group received any one diet. Total dry matter intake was highest in animals on diet C and lowest on B. However, straw DM intake was highest in animals on silage diet and lowest on untreated straw diet. Organic matter and crude fibre digestibility of silage and soaked straw diets were significantly higher (p<0.01) than those of untreated straw diet. Although the values were lower with soaked straw diet than on silage diet and soaked straw diet were significantly (p < 0.01) higher, however, the value for silage diet was not significantly different from that of soaked straw diet.

A Facile Approach to Fabrication of Hollow ZnO Nanoparticles

  • Cho, Gwang-Rae;Kim, Dong-Hyeon;Lee, Dong-Hoon
    • Composites Research
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    • v.31 no.3
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    • pp.94-98
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    • 2018
  • Well-defined, monodispersed hollow ZnO nanoparticles were successfully synthesized by a facile one-pot solution method at room temperature. Hollow ZnO nanoparticles were fabricated using polystyrene nanoparticles as seed particles. The removal of core particles via solvent extraction yields hollow nanoparticles. The structures and morphologies of the obtained products were characterized with Fourier transform infrared (FT-IR), Thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), X-ray diffraction pattern (XRD) and Scanning electron microscopy (SEM). The formation mechanism of the hollow structure of the ZnO nanoparticles was also investigated. The technique developed here is expected to be useful in the preparation other metal oxides and hollow architectures.

A study on relaxation of thermal stresses of heat-resistant systems (열차단 시스템에 있어서의 열응력 완화에 대한 연구)

  • Choi, Deok-Kee;Kim, Chang-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.1
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    • pp.16-22
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    • 1998
  • This paper addresses a method which can be used for analyzing thermal stresses of a functionally graded material(FGM) using semi-analytical approach. FGM is a nonhomogeneous material whose composition is changed continuously from a metal surface to a ceramic surface. An infinite one dimensional FGM plate is considered. The temperature distribution in the FGM is obtained by approximate Green's function solution. To expedite the convergence of the solutions, alternative Green's function solution is derived and shows good agreement with results from finite difference method. Thermal stresses are calculated using temperature distribution of the plate.

Fractional magneto-thermoelastic materials with phase-lag Green-Naghdi theories

  • Ezzat, M.A.;El-Bary, A.A.
    • Steel and Composite Structures
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    • v.24 no.3
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    • pp.297-307
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    • 2017
  • A unified mathematical model of phase-lag Green-Naghdi magneto-thermoelasticty theories based on fractional derivative heat transfer for perfectly conducting media in the presence of a constant magnetic field is given. The GN theories as well as the theories of coupled and of generalized magneto-thermoelasticity with thermal relaxation follow as limit cases. The resulting nondimensional coupled equations together with the Laplace transforms techniques are applied to a half space, which is assumed to be traction free and subjected to a thermal shock that is a function of time. The inverse transforms are obtained by using a numerical method based on Fourier expansion techniques. The predictions of the theory are discussed and compared with those for the generalized theory of magneto-thermoelasticity with one relaxation time. The effects of Alfven velocity and the fractional order parameter on copper-like material are discussed in different types of GN theories.

Development Plan of Wangdong and Hwangryong-River District (왕동.황룡강권 개발 기본계획 - 남도만향기행)

  • 박원규;박명권;신지훈
    • Journal of the Korean Institute of Landscape Architecture
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    • v.31 no.5
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    • pp.108-118
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    • 2003
  • There are plenty of ecological and traditional resources around Wandong and the Hwangryong-River district, and so the purpose of this development plan is to preserve ecological resources and traditional culture, and to utilize potential value of recreation in this site. Two major concepts are established in this plan one is “Green-Tourism”, the other is “Blue-Recreation”. In this development plan “Green-Tourism” means the effective tourism using ecological and traditional resources, while “Blue-Recreation” means the active tourism using waterfront and cultural facilities. The concept of “Green-Tourism” is applied to the Wangdong area, which is comprised of 6 theme zones. The concept of “Blue-Recreation” is applied to the Hwangryong-River area, which is composed of 4 theme zones. In total, 10 theme zones are planned according to characteristics found in the regional surroundings and cultural facilities of each zone.

A Study On The Value of Green Roof System in Passive House (친환경 주택에서 옥상녹화 시스템의 가치에 관한 연구)

  • Choi, Jae-Young;Lee, Jong-Kuk
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2009.04a
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    • pp.129-133
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    • 2009
  • country for green growth under minimizing boils to do change in climate under confronting boil the use of petrifaction resources energy and in change. Reduces the greenhouse gas and a environmental contamination, continuity for the growth which is possible demobilizes the greens and ecosystem, with alternative the roof which is an idle space from the construction water and the greens and uses creates in compliance with the effect which is various an energy economy and applies. Roof telerecording the synergy effect which follows with the effect which is various is not the energy saving which leads one effect which is simple in harmony and this lives together the environment which leads and possibility means that becomes the environmental element which hits.

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Implications and Situations of Hansalim's Green Marketing for Environmentally Friendly Agri-Products (한살림의 친환경농산물 그린마케팅 추진실태와 시사점)

  • Kim, Ho
    • Korean Journal of Organic Agriculture
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    • v.15 no.1
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    • pp.25-42
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    • 2007
  • Hansalim is a cooperative organization dealing with environmental-friendly/organic products(EFOP), which is pursuing both movement and business. Hansalim consists of producer's organizations and consumer's organizations, and always talks over organization structures and management directions all together. Hansalim has the movement goal of values and a world view for all lives, and so produces, distributes and consumes the EFOP as a way of achieving the goal. Hansalim was founded in 1986, and has about 130,000 members, the total sales of about 93.6 billions, 19 regional hansalims and one logistics center in 2006. Product strategy and promotion strategy are remarkable among green marketing mix of hansalim. Product strategy focuses safety, the environmental intimacy, differentiation and superiority of products. And the characteristics of promotion strategy are spontaneity, the self-control, cooperative spirit, mutual trust and close relationship among producers, consumers and staffs in charge.

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Current Status and Prospects of Ukrainian Wind Energy (우크라이나 풍력발전 현황 및 전망)

  • Kim, Hyun-Goo;Park, Hi-Chun
    • New & Renewable Energy
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    • v.7 no.1
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    • pp.8-14
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    • 2011
  • As is the case in Korea, the expansion of renewable energy dissemination is an essential matter in Ukraine when considering its energy consumption and dependence on energy import. While Korea has set about promoting the new and renewable energy industry on the back of the national policy on green growth, Ukraine expects a virtuous circle of renewable energy industry with green tariffs and the attraction of foreign capital in association with carbon emission trade. Utilizing its well-developed heavy industrial sector including the shipbuilding and automobile industries, Korea expects wind turbine manufacturing to become one of its next-generation growth engines. Ukraine is also trying to enter the wind turbine system or parts manufacturing industry based on its automobile industry and advanced aerospace technology. Although the Crimean region in Ukraine seems to have excellent wind resources, and thus shows great potential as a location for wind farm development, political instability has been a major obstacle to the attraction of foreign capital, leading to delayed investment.

Dispersant Effect on Thermal Performance of SG (증기발생기 열성능에 미치는 분산제 첨가효과)

  • Lee, Jae-Keun;Moon, Jeon-Soo;Yoon, Seok-Won;Maeng, Wan-Young
    • Journal of Hydrogen and New Energy
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    • v.22 no.4
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    • pp.546-551
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    • 2011
  • The corrosion on steam generator tubes of the secondary side of pressurized water reactor inhibits heat transfer. One of the most efficient techniques improving the heat transfer performance of a nuclear electric generation is a corrosion control. The environmental parameters mostly affecting corrosion are materials and chemical additives. It seems that no further corrosion occurs in steels with Polyacrylic acid polymer dispersant treatment. Polyacrylic acid forms a protective coating with uniform thickness on metal surface. Polyacrylic treatment appears to be the most convenient way to enhance the thermal performance by the thermal conductivity improvement in steam generators.