• Title/Summary/Keyword: Energy transformation

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A model for Phase Transformation of Microalloyed Low Carbon Steel Combined with Nb Precipitation Kinetics (Nb 석출 거동을 고려한 저탄소강의 상변태 모델)

  • Kim, D.W.;Cho, H.H.;Park, S.;Kim, S.H.;Kim, M.J.;Lee, K.;Han, H.N.
    • Transactions of Materials Processing
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    • v.26 no.1
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    • pp.48-54
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    • 2017
  • The dissolution and precipitation of Nb, which has been known as strong carbide-forming element, play a key role in controlling phase transformation kinetics of microalloyed steels. In this study, we analyzed both numerically and experimentally the precipitation behavior of Nb-microalloyed steel and its effect on the austenite decomposition during cooling. Nb precipitation in austenite matrix could be predicted by the thermo-kinetic software MatCalc, in which interfacial energy between precipitate and matrix is calculated. The simulated precipitation kinetics fairly well agrees with the experimental observations by TEM. Austenite decomposition, which is strongly affected by Nb precipitation during cooling, was measured by dilatometry and was modeled on the basis of a Johnson-Mehl-Avrami-Kolmorgorov(JMAK) equation. It was confirmed that the dissolved Nb delays the austenite decomposition, whereas, the precipitated Nb accelerates phase transformation during the austenite decomposition.

IN-CYLINDER FLOW ANALYSIS USING WAVELET ANALYSIS

  • Park, D.;Sullivan, P.E.;Wallace, J.S.
    • International Journal of Automotive Technology
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    • v.7 no.3
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    • pp.289-294
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    • 2006
  • Better fundamental understanding of the interactions between the in-cylinder flows and combustion process is an important requirement for further improvement in the fuel economy and emissions of internal combustion(IC) engines. Flow near a spark plug at the time of ignition plays an important role for early flame kernel development(EFKD). Velocity data measurements in this study were made with a two-component laser Doppler velocimetry(LDV) near a spark plug in a single cylinder optical spark ignition(SI) engine with a heart-shaped combustion chamber. LDV velocity data were collected on an individual cycle basis under wide-open motored conditions with an engine speed of 1,000rpm. This study examines and compares the flow fields as interpreted through ensemble, cyclic and discrete wavelet transformation(DWT) analysis. The energy distributions in the non-stationary engine flows are also investigated over crank angle phase and frequency through continuous wavelet transformation(CWT) for a position near a spark plug. Wavelet analysis is appropriate for analyzing the flow fields in engines because it gives information about the transient events in a time and frequency plane. The results of CWT analysis are provided and compared with the mean flows of DWT first decomposition level for all cycles at a position. Low frequency high energy found with CWT corresponds well with the peak locations of the mean velocity. The high frequency flows caused by the intake jet gradually decay as the piston approaches the bottom dead center(BDC).

Demystifying an Appropriate Use of a Performer's 'Energy' Where the Performer's Body Becomes 'Real'

  • Son, Bong-Hee
    • International Journal of Advanced Culture Technology
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    • v.10 no.2
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    • pp.148-153
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    • 2022
  • This thesis investigates the meaning of a performer's energy taking into an account of the full bodily engagement as the flow of energy and/or psychophysical readiness focusing specifically on the significance of qualitative bodily transformation. In this contemporary era, the dominance of performer training and its approaches to acting/training has very frequently meant that how to play a character in a textual based approach by emphasizing on interpreting and impersonating the role as real as possible. In this sense, as a performer trainer, from my observation and research findings shows that it is common for the term energy is not to be motivated by what a performer's body needs within a specific moment in specific performance which they are working on. To address the problematic issues, this thesis begins by interrogating the practical meaning of transformation with addressing the principle and process of movement by means of the flow of energy on stage. For a performer, inhabiting/integrating his/her body and mind as oneness and/or unity means s/he sincerely encounter, confront, and therefore listen to his/her body in here and now. Because since the performer's physical appearance completely defined his/her psychological state, no one can play either the past or the future in the moment. In this manner, an appropriate use of energy synonymous with the flow of energy correspondence with the given time and space in which the performer's body informs and initiates movement as necessary action. To be precise, the performer's bodily movement either visible or invisible in a sense of training and rehearsal is perceived as attaining or achieving psychophysical involvement as the full body engagement which enable to make the event happen in the right moment. Here, this thesis argues that the significance of a performer's inner intensity reminds us of the necessity of qualitative transformation on which the performer could discover his/her own mode of awareness as well as a way his/her body function in the given circumstance. From this point of view, this research finding would advocates that the performer's body maintains in the field of energy flow where his/her conscious effort and/or mindfulness disappear. The performer's movement is a manifestation of the whole bodily engagement by means of being as real in that moment rather than representing reality.

The Change of Microstructures by Low Temperature Aging in Y-TZP (저온 열처리에 의한 Y-TZP 미세조직의 변화)

  • Lee, Jong-Kook;Kim, Hwan
    • Journal of the Korean Ceramic Society
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    • v.27 no.6
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    • pp.735-740
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    • 1990
  • The phase transformation of Y-TZP by low temperature aging treatments and its related behaviors of crack formation were investigated. The kinetics of phase transformation was greatly dependent on the amounts of Y2O3, grian size and microstructures of sintered body. The phase transformation happened to start at specimen surface and near the pore in the first place, where the change of strain energy during the phase transformation was small and the water vapor that accelerated phase transformation easily diffused.

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Research towards New Innovation Strategies in Korea via Focused Group Method

  • Park, Sung-Uk;Kwak, Jae-Won;Kim, Hyun-Cheol
    • Asian Journal of Innovation and Policy
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    • v.11 no.2
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    • pp.222-237
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    • 2022
  • As the COVID-19 pandemic crisis left developing countries with economic setbacks, it is high time to highlight that innovative technologies lead the digital economy. The big powers including the United States and China are already implementing industrial policies that involve large-scale fiscal expenditures to secure the lives and safety of their people. To prepare for the future up to 2025, this paper reflects opinions of industry-academia-research experts regarding changes in the external environment and industry trends. By reflecting results of focus group interviews and changes in the external environment and industry trends, a new high-level 5X strategy (Digital Transformation, Energy Transformation, Bio Health Transformation, Supply Chain Transformation, and Research Transformation) to solve national tasks required for the existing ten policy demand fields and ten agenda during lower-level policy implementation stages were derived.

Effect of strain rate and stress triaxiality on fracture strain of 304 stainless steels for canister impact simulation

  • Seo, Jun-Min;Kim, Hune-Tae;Kim, Yun-Jae;Yamada, Hiroyuki;Kumagai, Tomohisa;Tokunaga, Hayato;Miura, Naoki
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2386-2394
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    • 2022
  • In this paper, smooth and notched bar tensile tests of austenitic stainless steel 304 are performed, covering four different multi-axial stress states and six different strain rate conditions, to investigate the effect of the stress triaxiality and strain rate on fracture strain. Test data show that the measured true fracture strain tends to decrease with increasing stress triaxiality and strain rate. The test data are then quantified using the Johnson-Cook (J-C) fracture strain model incorporating combined effects of the stress triaxiality and strain rate. The determined J-C model can predict true fracture strain overall conservatively with the difference less than 20%. The conservatism in the strain-based acceptance criteria in ASME B&PV Code, Section III, Appendix FF is also discussed.

The critical angle of seismic incidence of transmission tower-line system based on wavelet energy method

  • Tian, Li;Dong, Xu;Pan, Haiyang;He, Xiaoyu
    • Earthquakes and Structures
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    • v.17 no.4
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    • pp.387-398
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    • 2019
  • On the basis that ground motions may arrive at a structure from any horizontal direction and that different directions of seismic incidence would result in different structural dynamic responses, this paper focuses on orienting the crucial seismic incidence of transmission tower-line systems based on the wavelet energy method. A typical transmission tower-line system is chosen as the case study, and two finite element (FE) models are established in ABAQUS, with and without consideration of the interaction between the transmission towers and the transmission lines. The mode combination frequency is defined by considering the influence of the higher-order modes of the structure. Subsequently, wavelet transformation is performed to obtain the total effective energy input and the effective energy input rate corresponding to the mode combination frequency to further judge the critical angle of seismic incidence by comparing these two performance indexes under different seismic incidence angles. To validate this approach, finite element history analysis (FEHA) is imposed on both FE models to generate comparative data, and good agreement is found. The results demonstrate that the wavelet energy method can forecast the critical angle of seismic incidence of a transmission tower-line system with adequate accuracy, avoiding time-consuming and cumbersome computer analysis. The proposed approach can be used in future seismic design of transmission tower-line systems.

Transformation of Industrial Parks in the Direction of Providing of the Purposes Achievement of Sustainable Development

  • Melnychenko, Anatolii;Shevchuk, Nataliia;Babiy, Irina;Blyznyuk, Tetyana;Akimova, Olena
    • International Journal of Computer Science & Network Security
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    • v.22 no.1
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    • pp.7-14
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    • 2022
  • The presented research is devoted to the problems of achieving the goals of sustainable development, which will contribute to the development of industrial parks and their transformation into eco-industrial parks. The importance of the functioning of industrial parks and their transformation into eco-industrial ones in the direction of achieving sustainable development goals is substantiated. The development of industrial parks and their transformation through the coordination of dynamic development processes and the establishment of a system of mutually beneficial relations, due to the peculiarities of their functioning aimed at achieving sustainable development goals ensure the achievement of sustainable spatial development. Transformation of industrial parks will contribute to: increasing tax revenues of local budgets, increasing employment in the regions, raising public awareness of the need for environmentally friendly, energy efficient production, increasing the balance and harmony of social, economic and environmental development, modernization of territorial communities and regional enterprises resources and increase entrepreneurial initiative, rational use of available resources, intensification of small and medium enterprises, including innovation. The authors' scientific achievements are the substantiation of the principles of functioning of industrial parks in order to achieve the goals of sustainable development, which are based on a systematic approach and provide for the transformation into eco-industrial parks.