• 제목/요약/키워드: Mode Transition

검색결과 494건 처리시간 0.027초

Self-catalytic Growth of ${\beta}$-Ga2O3 Nanowires Deposited by Radio-Frequency Magnetron Sputtering

  • 최광현;강현철
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.291.2-291.2
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    • 2013
  • Growth behavior of b-Ga2O3 nanowires (NWs) on sapphire(0001) substrates during radio-frequency magnetron sputtering is reported. Upon fabrication, flat thin films grew initially, subsequent to which, NW bundles were formed on the surface of thin film with increasing film thickness. This transition of the growth mode occurred only at temperatures greater than ${\sim}450^{\circ}C$. The b-Ga2O3 NWs were grown through the self-catalytic vapor-liquid-solid mechanism with self-assembled Ga seeds. Secondary growth of NWs, which occurred from the sides of primary NWs resulting in branched NW structures, was also observed. Finally, the room temperature photoluminescence properties of as-grown and annealed b-Ga2O3 NW samples were investigated.

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Thermo-Acoustic Instability in the Horizontal Rijke Tube

  • Song Woo-Seog;Lee Seung-Bae;Shin Dong-Shin;Na Yang
    • Journal of Mechanical Science and Technology
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    • 제20권6호
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    • pp.905-913
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    • 2006
  • The instability curve of a Rijke tube system was obtained accurately by following different paths of heat power and flow-rate for three regions and by defining its locus from the criterion based on the measured sound pressure levels. The unstable limits in the region of flow-rate lower than that at the minimal power are compared with previous data. To observe the effect of turbulence on the unstable limits, inflow turbulence was introduced by placing a bundle of circular cylinders upstream of the heating part ($50). The large-amplitude inflow fluctuation may delay the transition of the chamber acoustic mode to the unstable Bone even at a sufficient power.

Effect of Temperature on Photoinduced Reorientation of Azobenzee Chromophore in the Side Chain Copolymers

  • 최동훈
    • Bulletin of the Korean Chemical Society
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    • 제20권9호
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    • pp.1010-1016
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    • 1999
  • We synthesized the photoresponsive side chain polymers containing aminonitro azobenzene for studying the effect of temperature on photoinduced birefringence. Four different copolymers were prepared using methacrylate, α-methylstyrene, and itaconate monomer. Photoisomerization was observed under the exposure of UV light using UV-VIS absorption spectroscopy. Reorientation of polar azobenzene molecules induced optical anisotropy under a linearly polarized light at 532 nm. The change of the birefringence was observed with increasing the sample temperature under a continuous irradiation of excitation light. We could estimate the activation energy of molecular motion in thermal and photochemical mode. Besides the effect of glass transition temperature on the activation energy, we focused our interests on the effect of geometrical hindrance of polar azobenzene molecules and cooperative motion of environmental mesogenic molecules in the vicinity of polar azobenzene molecules.

A Theoretical Study of Gas-Surface Phonon Scattering: Model He-Si(100) Bulk and Reconstructed Surfaces

  • Seung Chul Park;Chang Hwan Rhee;Woong Lin Hwang;Yoon Sup Lee;Myung Soo Kim
    • Bulletin of the Korean Chemical Society
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    • 제12권4호
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    • pp.387-392
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    • 1991
  • We present a theoretical investigation of the inelastic atom-surface phonon scattering for a model He-Si(100) system by the classical trajectory-quantum forced oscillator(DECENT) method. Single and multi-phonon transition probabilities of normal modes are calculated for several initial beam orientations and several initial kinetic energies. In order to understand surface structure effects, the calculation has been done on both reconstructed and unreconstructed surfaces of the He/Si(100) system. The origin of mode specificity for energy transfer is discussed. The contribution of one, two, and multi-phonon events to the total energy transfer between 0 and 600 K is also given.

ATO 장치의 자동 열차속도 조절 알고리즘에 관한 연구 (A Study for Automatic Train Speed Regulation Algorithm of ATO)

  • 김중환;강리택
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 1998년도 추계학술대회 논문집
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    • pp.210-218
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    • 1998
  • The ATO(Automatic Train Operation) System is used for train operation instead of drivers. It is interfaced with TCMS(Train Control and Monitoring System) and ATC/TWC system in the train and wayside facilities. In this paper describes configuration of ATO, specification of ATO hardware, construction of ATO software and the algorithm fur automatic train speed regulation in the carborn ATO system. ATO Application Software is consist of ART, SPR, REG, SRV and PSM tasks. ART task is main control part of the ATO that determine ATO control, ATO mode, state transition. SPR determine speed reference according to train motion status, track data, train data and restricted train speed. REG task regulated train speed form the starting of one station to the precision stop at the other station under the result of ART and SPR tasks. In this paper, a algorithm for the train speed regulation while running is described.

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Interaction Between Barbiturate and Membrane Components

  • Yu, Byung-Sul;Jo, Seong-Bong;Kim, Chong-Kook;Hwang, Young-Sik
    • Archives of Pharmacal Research
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    • 제13권3호
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    • pp.246-251
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    • 1990
  • Intermolecular interaction between barbiturates and membrane components such as phospholipid and cholesterol were investigated on $^1$H-NMR spectra and infrared spectra. According to previous reports, barbiturates interacted with phospholipid through intermolecular hydrogen bonds. We also investigated thi observation using dipalmitoyl-phosphatidylcholine (DPPC) as phospholipid in deuterochloroform, and characterized quantitatively. Also, the observed drug could interact with cholesterol which is one of the major components of biomembranes through hydrogen bonds. It was the carbonyl groups of barbiturate and the hydroxyl group of cholesterol that formed hydrogen bond complex. In addition to spectroscopic studies, we investigated the direct effect of phenobarbital on lipid multibilayer vesicles, whose compositions were varied, by calorimetric method. Phenobarbital caused a reduction in the temperature of phase transition of vesicles. These studies may provided a basis for interpreting the mode of action of barbiturates.

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양극산화 모드 전환을 통한 기능성 알루미늄 표면 연구 (Fabrication of functional aluminum surface through anodization mode transition)

  • Park, Youngju;Jeong, Chanyoung
    • 한국표면공학회지
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    • 제55권6호
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    • pp.417-424
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    • 2022
  • This research develops an easy-to-use, environmentally friendly method for fabricating functional 1050 aluminum alloy surfaces with excellent corrosion resistance. Functional aluminum surfaces with various nanostructures are fabricated by controlling the experimental conditions of anodizing process. The experiment used a multi-step anodizing process that alternates between two different anodizing modes, mild anodizing (MA) and hard anodizing (HA), together with a pore-widening (PW) process. Among them, the nanostructured surface with a small solid fraction shows superhydrophobicity with a contact angle of more than 170° after water-repellent coating. In addition, the surface with superhydrophobicity is difficult for corrosive substances to penetrate, so the corrosion resistance is greatly improved.

"Homeward returning": A Plebeian Romance and Naturalization of Vagrancy in John Milton's Paradise Lost

  • Cho, Hyunyoung
    • 영어영문학
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    • 제64권1호
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    • pp.135-150
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    • 2018
  • Focusing on the hermeneutic instability of a key word of Paradise Lost, "wander," this study attempts to situate John Milton's early modern epic in the longue $dur{\acute{e}}e$ historical transition from seignorial to capitalist mode of production, especially the displacement and reorganization of producer population, a corollary of early phase of modernization. The historic experience of vagrancy and its normalization, and the concomitant shift of the primary human sociability from given to voluntary bonds, I suggest, shape and inform Milton's early modern rewriting of the Biblical story of the fall and his revising of the heroic epic romance into a plebeian romance of a wandering, companionate couple. While building on the critical consensus on this poem's deliberate distancing from the tradition of classical epic and chivalric romance, this essay argues that Milton re-appropriates and re-channels the aspirational aspect of chivalric wandering, or mobility, for his plebeian heroes, a companionate conjugal couple. The hermeneutic instability of the word wander, this essay suggests, captures the duality of the historic experience of vagrancy, both the tragic experience of displacement and the liberational and uplifting dimension of that experience.

Education in Cyberspace: University as Universality

  • Shapoval, Oksana;Kotlyaria, Svitlana;Medvedieva, Alla;Lishafai, Oleksandr;Barabash, Oleh;Oleksyuk, Oksana
    • International Journal of Computer Science & Network Security
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    • 제21권11호
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    • pp.333-337
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    • 2021
  • The article reveals the essence of cyber socialization influencing the process of education and development. The general and potential possibilities of cyber socialization in the process of using the cyberspace of the Internet environment are presented. The sudden transition to distance learning in the spring of 2020 put the pedagogical community in the face of problems related to the content, organizational and methodological basis of the educational process. During the training in distance mode, a rich experience was gained in the use of information and communication technologies. The article discusses the techniques and methods of teaching using the capabilities of information and communication and digital technologies.