• Title/Summary/Keyword: Energy dependence

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STRUCTURAL STABILITY RESULTS FOR THE THERMOELASTICITY OF TYPE III

  • Liu, Yan
    • Bulletin of the Korean Mathematical Society
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    • v.51 no.5
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    • pp.1269-1279
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    • 2014
  • The equations arising from the thermoelastic theory are analyzed in a linear approximation. First, we establish the convergence result on the coefficient c. Next, we establish that the solution depends continuously on changes in the coefficient c. The main tool used in this paper is the energy method.

Urban Revitalization Policies of the Ruhr Area, Germany: Case Studies on the Cities of Oberhausen and Gelsenkirchen (독일 루르지역의 도시재생정책: 오버하우젠시와 겔젠키르헨시를 사례로)

  • Shin, Dong-Ho
    • Journal of the Economic Geographical Society of Korea
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    • v.18 no.1
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    • pp.60-75
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    • 2015
  • The Ruhr area in the Northwestern Germany grew rapidly from the 1850s based on coal mining and iron and steel industries, playing a key role as an engine of industrial growth. Since the 1950s, however, the area has been experiencing a serious economic crisis as the traditional industries declined. The crisis was comprised of increasing unemployment and abandoned industrial lands and facilities. Oberhausen and Gelsenkirhen are typical cities of the Ruhr, characterized by such economic crisis. Oberhausen attempted to solve the problems by developing a large leisure town, composed of a sopping mall, restaurants, and other arts and cultural activities, on a former steel mill site. Gelsenkirhen, on the other hand, went on to promote renewable energy industries, business incubators, and energy-saving housing complexes. This paper analyses the processes and outcomes of urban revitalization policies of the two cities, based on the path dependence theory, and draws theoretical and policy implications.

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Analysis of Determinants of Carbon Dioxide Emissions in Korea: Considering Cross-sectional Dependence and Heterogeneous Coefficient (우리나라 이산화탄소 배출량 결정요인 분석: 횡단면 의존성과 계수 이질성을 고려하여)

  • Kim, So-youn;Ryu, Suyeol
    • Journal of the Economic Geographical Society of Korea
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    • v.24 no.4
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    • pp.400-410
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    • 2021
  • This study analyzed the determinants of carbon dioxide emissions through the expanded STIRPAT model using panel data from 16 metropolitan cities and provinces in Korea from 2000 to 2019. After testing cross-sectional dependence and coefficient heterogeneity of panel data, we performed analysis using MG, CCEMG, and AMG estimation methods reflected these characteristics. The results of analysis using the AMG estimation method are as follows. The coefficients of income, population, and energy intensity were statistically significant with a positive sign, but urbanization was statistically insignificant. Reduction of carbon dioxide emissions in Korea can be achieved through an increase in energy efficiency and sustainable economic growth. It is necessary to establish a policy that can contribute to sustainable economic growth by inducing productivity improvement through technology innovation reducing carbon dioxide emissions in the long-term as well as building a low-carbon society through active development of carbon dioxide reduction technology.

The rate-determining step in the dark state recovery process in the photocycle of PYP

  • Sasaki, Jun;Kumauchi, Masato;Hamada, Norio;Tokunaga, Fumio
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.130-133
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    • 2002
  • The last step in the photocycle of photoactive yellow protein (PYP) is a spontaneous recovery of the dark state from the active state in which the p-coumaric acid chromophore is thermally isomerized, concomitantly with the deprotona- tion of the chtomophore and the refolding of the protein moicty. For the purpose of understanding the mechanism of the thermal back-isomerization, we have investigated the rate-determining step by analyzing mutant PYPs of Met100, which was previously shown to play a major role in facilitating the reaction (1). The mutation to Lys, Leu, Ala, or Glu decelerated the dark state recovery by 1 to 3 three orders of magnitude. By evaluating temperature-dependence and pH-dependence of the kinetics of the dark state recovery, it was found that the retardation by mutations resulted from elevation of the activation enthalpy ( H$\^$┿/) and that the pKa of the chromophore, which was affected by the mutation, is in a linier correlation with the amplitude of the rate constants. It was, therefore, deduced from the correlation that the free energy for crossing the activated state in the dark recovery process is proportional to the free energy for the deprotonation of the chromophore, identifying the rate-determining step as the deprotonation of the chromophore. (1) Devanathan, S. Genick, U. K. Canestrelli, I. L. Meyer, T. E. Cusanovich, M. A. Getzoff, E. D. Tollin, G., Biochemistry 1998, 37, 11563 - 11568

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Syngas-Oxygen Combustion Characteristics of a Swirl-Stabilized Premixed Flame (합성가스-순산소 예혼합 화염의 연소특성)

  • Cho, Ju-Hyeong;Park, Jun-Hong;Jeon, Choong-Hwan;Ahn, Koo-Kyoung;Kim, Han-Seok
    • Transactions of the Korean hydrogen and new energy society
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    • v.21 no.6
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    • pp.561-569
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    • 2010
  • The present study deals with experimental investigations on the syngas-oxygen combustion characteristics of a swirl-stabilized premixed flame in a 10 kW combustor. The effect of hydrogen in syngas has been investigated with different swirl angles to identify the role of hydrogen and swirl strength on the flame stability and CO emissions. The results show that hydrogen addition extended the blowout limit while narrowing the flashback limit. The dependence of blowout on the swirl angle is negligible while the dependence of flashback on the swirl angle is evidenced by two regimes depending on the amount of hydrogen. CO emission is decreased with increasing excess $O_2$ supply or increasing hydrogen content. Chemiluminescence diagnostics is utilized to provide information on the structure of a swirl-stabilized premixed flame. The OH chemiluminescence intensity is more concentrated near the burner exit with an increase in the hydrogen content, which results from high reactivity of hydrogen.

Nonstoichimetry (x) of Nuclear Materials UO2+x and $(Ce_yU_{1-y})O_{2+x}$ at High Temperatures as a Function of Oxygen Activity$(a_o_2)$

  • Kang, Sun-Ho;Yoo, Han-Ill;Kim, Han-Soo;Lee, Young-Woo
    • The Korean Journal of Ceramics
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    • v.4 no.2
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    • pp.78-82
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    • 1998
  • The oxygen nonstoichiometry (x) of UO$_{2+x}$ and $(Ce_yU_{1-y})O_{2+x}$ (y=0.05, 0.25) has been measured as a function of oxygen activity (a02) at 100$0^{\circ}C$ by a solid state coulometri titration technique. The results for UO$_{2+x}$ are in a good agreement with literature data and the ao2-dependence of the nonstoichimetry has been well explained with (2:2:2) cluster model. The equilibrium oxygen activity of $(Ce_yU_{1-y})O_{2+x}$ increases with Ce-content (y) for given nonstoichiometry (x), which is ascribed to the fact that Ce is present as Ce$^{3+}\; and\; Ce^{4+}$, and, therefore, the addition of Ce reduces the oxidation capacity of UO$_{2+x}$. From the oxygen activity dependence of x in $(Ce_yU_{1-y})O_{2+x}$ the defect structure of $(Ce_yU_{1-y})O_{2+x}$ is discussed.

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