• Title/Summary/Keyword: Upgrading

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Seismic upgrading of structures with different retrofitting methods

  • Guneyisi, Esra Mete;Azez, Ibrahim
    • Earthquakes and Structures
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    • v.10 no.3
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    • pp.589-611
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    • 2016
  • This paper presents an analytical study aimed at evaluating the seismic performance of steel moment resisting frames (MRFs) retrofitted with different approaches. For this, 3, 6 and 12 storey MRFs having four equal bays of 5 m were selected as the case study models. The models were designed with lateral stiffness insufficient to satisfy code drift and hinge limitations in zones with high seismic hazard. Three different retrofit strategies including traditional diagonal bracing system and energy dissipation devices such as buckling restrained braces and viscoelastic dampers were used for seismic upgrading of the existing structures. In the nonlinear time history analysis, a set of ground motions representative of the design earthquake with 10% exceedance probability in fifty years was taken into consideration. Considering the local and global deformations, the results in terms of inter-storey drift index, global damage index, plastic hinge formations, base shear demand and roof drift time history were compared. It was observed that both buckling-restrained braces and viscoelastic dampers allowed for an efficient reduction in the demands of the upgraded frames as compared to traditional braces.

Trends of Green Policies of Biogas Renewable Technology using POME in Malaysia (말레이시아 팜오일폐수 POME(Palm Oil Mill Effluent)를 이용한 바이오가스 신재생에너지기술 그린정책 동향)

  • Park, Young Gyu
    • Journal of Korea Society of Waste Management
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    • v.35 no.7
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    • pp.571-586
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    • 2018
  • The Malaysian biogas upgrading technologies and policies were examined. In Malaysia, the regulation of palm oil mill effluent (POME) has been enforced to reduce the biochemical oxygen demand to 20 ppm and the biogas capture in the palm oil mills have been recently enforced for renewable energy. A huge amount of organic waste is produced from POME, and 80 million tons from palm oil trees, every year. Due to the renewable energy trends, the Malaysian government is modifying the use of biogases as fuels in favor of their conversion into compressed natural gas (CNG) and other chemicals; various green policies are being promoted because of many advantages of the organic substances. The Korean policies for biogas are a good model for exporting environmental plants after upgrading the digestion and purification technologies. Therefore, this article introduces the current status of POME and biogas production in Malaysia, it could encourage creating a new market for biomethane.

What Makes Korea's New Regional Policy Workable? (신지역정책의 작동요인에 관한 연구)

  • Cho, Myung-Rae
    • Journal of the Economic Geographical Society of Korea
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    • v.14 no.4
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    • pp.486-505
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    • 2011
  • The Korean miracle of economic growth or development has been quite well known across the world up to now, while being subject to theorization of its model. Compared with this, however, it is quite surprising to see how little about the spatial aspect of Korean development has been exposed in the field of development studies. In fact, for Korea, competent regional policy has turned out to be an important success factor for the spatial upgrading of a low-tech growth regime into a hi-tech one. This paper dissects Korea's regional policy experiences in three aspects from which it draws up a three-tier lesson. The first aspect is the conventional (overall) regional spatial upgrading policy of a developmental regime put in place since the 1960s onwards. The second is the new regional policy tailored to the regionalization of technological and industrial diffusion for new knowledge-based economy. The third is the prospective regional policy for the future advancement of the Korean economy.

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Catalytic Fast Pyrolysis of Tulip Tree (Liriodendron) for Upgrading Bio-oil in a Bubbling Fluidized Bed Reactor

  • Ly, Hoang Vu;Kim, Jinsoo;Kim, Seung-Soo;Woo, Hee Chul;Choi, Suk Soon
    • Clean Technology
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    • v.26 no.1
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    • pp.79-87
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    • 2020
  • The bio-oil produced from the fast pyrolysis of lignocellulosic biomass contains a high amount of oxygenates, causing variation in the properties of bio-oil, such as instability, high acidity, and low heating value, reducing the quality of the bio-oil. Consequently, an upgrading process should be recommended ensuring that these bio-oils are widely used as fuel sources. Catalytic fast pyrolysis has attracted a great deal of attention as a promising method for producing upgraded bio-oil from biomass feedstock. In this study, the fast pyrolysis of tulip tree was performed in a bubbling fluidized-bed reactor under different reaction temperatures, with and without catalysts, to investigate the effects of pyrolysis temperature and catalysts on product yield and bio-oil quality. The system used silica sand, ferric oxides (Fe2O3 and Fe3O4), and H-ZSM-5 as the fluidized-bed material and nitrogen as the fluidizing medium. The liquid yield reached the highest value of 49.96 wt% at 450 ℃, using Fe2O3 catalyst, compared to 48.45 wt% for H-ZSM-5, 47.57 wt% for Fe3O4 and 49.03 wt% with sand. Catalysts rejected oxygen mostly as water and produced a lower amount of CO and CO2, but a higher amount of H2 and hydrocarbon gases. The catalytic fast pyrolysis showed a high ratio of H2/CO than sand as a bed material.