• Title/Summary/Keyword: Two-Phase Theory

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A Study on the Instability Criterion for the Stratified Flow in Horizontal Pipe at Cocurrent Flow Conditions

  • Sung, Chang-Kyung
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.10a
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    • pp.463-468
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    • 1997
  • This paper presents a theoretical approach of the instability criterion from stratified to nonstratified flow in horizontal pipe at cocurrent flow conditions. The new theoretical instability criterion for the stratified and nonstratified flow transition in horizontal pipe has been developed by hyperbolic equations in two-phase flow, Critical flow condition criterion and onset of slugging at cocurrent flow condition correspond to zero and imaginary characteristics which occur when the hyperbolicity of a stratified two-phase flow is broken, respectively. Through comparison between results predicted by the present theory and the Kukita et al.[1] experimental data of pipes, it is shown that they are in good agreement with data.

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Study on the Phase Diagram for the Polymer Bland (Polymer Bland에서의 상평형에 관한 연구)

  • Kim, Sang-Min
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.9 no.1
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    • pp.19-24
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    • 2003
  • We study on the phase diagram of the polymer blend. For this purpose, one PS (polystyrene) and two PI(polyisoprene) were employed whose molecular weights were low enough to make the experimental determinations possible. The weight-average molecular weight(Mw) of PS was 2514, and Mws of two PIs were 2700. Interaction energy density (IED) of the Flory-Huggins lattice theory was defined as a function of temperature and composition, and the consequent equations for the binodal, and critical points were derived. By fitting the experimental binodal points to the derived binodal curve with a nonlinear regression method, the expression for the IED was determined. And the expression for the IED obtained from this study was compared with those reported in the literatures. Also were discussed the importance of accuracy in the expression the IED, and the IED's dependency on the temperature, composition and molecular weights.

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A Theory of Interface between Polymer and Polymer Mixture

  • Yoon Kyung-Sup;Park Hyungsuk
    • Bulletin of the Korean Chemical Society
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    • v.15 no.1
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    • pp.45-52
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    • 1994
  • We present a theoretical study of the non-symmetrical A/BC polymeric system. The polymer blends consist of two phases, a pure polymeric phase A on one side and a mixture of polymers B as a compatibilizer and C on the other. The adsorption of homopolymer B to the interface improves the interfacial adhesion between two phases. By employing the functional integral techniques, we derive the mean-field equations and solve them numerically to obtain the interfacial properties including the concentration profiles in the limit of infinite molecular weight for the polymers. Thecalculations of the interfacial properties are performed for typical values of the Flory X parameters and the volume fraction of polymer B in the asymptotic mixture phase. The interfacial adsorption of polymer B and the degrees of the specific interaction between the polymers play an important role in modification of the interfacial properties.

A novel of rotating nonlocal thermoelastic half-space with temperature-dependent properties and inclined load using the dual model

  • Samia M. Said
    • Structural Engineering and Mechanics
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    • v.90 no.5
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    • pp.459-466
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    • 2024
  • Eringen's nonlocal thermoelasticity theory is used to study wave propagations in a rotating two-temperature thermoelastic half-space with temperature-dependent properties. Using suitable non-dimensional variables, the harmonic wave analysis is used to convert the partial differential equations to ordinary differential equations solving the problem. The modulus of elasticity is given as a linear function of the reference temperature. MATLAB software is used for numerical calculations. Comparisons are carried out with the results in the context of the dual-phase lag model for different values of rotation, a nonlocal parameter, an inclined load, and an empirical material constant. The distributions of physical fields showed that the nonlocal parameter, rotation, and inclined load have great effects. When a nonlocal thermoelastic media is swapped out for a thermoelastic one, this approach still holds true.

Two-phase Multicast in Wormhole-switched Bidirectional Banyan Networks (웜홀 스위칭하는 양방향 베니언 망에서의 두 단계 멀티캐스트)

  • Kwon, Wi-Nam;Kwon, Bo-Seob;Park, Jae-Hyung;Yun, Hyeon-Su
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.3
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    • pp.255-263
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    • 2000
  • A multistage interconnection network is a suitable class of interconnection architecture for constructing large-scale multicomputers. Broadcast and multicast communication are fundamental in supporting collective communication operations such as reduction and barrier synchronization. In this paper, we propose a new multicast technique in wormhole-switched bidirectional multistage banyan networks for constructing large-scale multicomputers. To efficiently support broadcast and multicast with simple additional hardware without deadlock, we propose a two-phase multicast algorithm which takes only two transmissions to perform a broadcast and a multicast to an arbitrary number of desired destinations. We encode a header as a cube and adopt the most upper input link first scheme with periodic priority rotation as arbitration mechanism on contented output links. We coalesce the desired destination addresses into multiple number of cubes. And then, we evaluate the performance of the proposed algorithm by simulation. The proposed two-phase multicast algorithm makes a significant improvement in terms of latency. It is noticeable that the two-phase algorithm keeps broadcast latency as efficient as the multicast latency of fanout 2^m where m is the minimum integer satisfying $2^m{\geq} {\sqrt{N}}$ ( N is a network size).

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Study on Suk Gock's Fortify Yang Theory (석곡 이규준의 부양이론에 관한 연구)

  • Hwang Won Duek
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.3
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    • pp.713-723
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    • 2004
  • With regard of YinYang and Five Elements Theory, predominance of Yin or Yang is a key point to discuss Nourishin Ying or Reinforcing Yang. There are two major branches about studying predominance of Yin or Yang. Zhu Danxi advocated the theory that Yang was always in excess while Yin was often deficient, and thus belonged to the School for Nourishing the Yin. Zhang Jie-bin advocated that Yang is easily deficient while Yin is easily sufficient. It seems that they studied Wang Bing's 'Ministerial fire rule on all thing instead of Imperial Fire' and right Kidney Mingmen theory in Nan Jing, which are both related to the First Yang in the Book of Changes and say Mingmen fire is the host of the body. Zhu Danxi insisted that Mingmen fire was easily in excess and likely to become pathogenic fire while Water phase was easily in deficiency, so the doctors should nourish Yin and suppress Yang. Zhang Jie-bin said that Mingmen fire is vulnerable so the doctors should fortify yang and reinforce Mingmen fire. Suk Gock Master Lee thought that the Book of Changes and Nei Jing had a viewpoint of Fortify Yang as regards of some distinguished Physicians' articles about predominance of YinYang. The author's going to discribe Suk Gock's Fortify Yang Theory with viewpoints of Nei Jing and the Book of Changes.

A novel four variable refined plate theory for wave propagation in functionally graded material plates

  • Fourn, Hocine;Atmane, Hassen Ait;Bourada, Mohamed;Bousahla, Abdelmoumen Anis;Tounsi, Abdelouahed;Mahmoud, S.R.
    • Steel and Composite Structures
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    • v.27 no.1
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    • pp.109-122
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    • 2018
  • In This work an analysis of the propagation of waves of functionally graduated plates is presented by using a high order hyperbolic (HSDT) shear deformation theory. This theory has only four variables, which is less than the theory of first order shear deformation (FSDT). Therefore, a shear correction coefficient is not required. Unlike other conventional shear deformation theories, the present work includes a new field of displacement which introduces indeterminate integral variables. The properties of materials are supposed classified in the direction of the thickness according to two simple distributions of a power law in terms of volume fractions of constituents. The governing equations of the wave propagation in the functionally graded plate are derived by employing the Hamilton's principle. The analytical dispersion relation of the functionally graded plate is obtained by solving an eigenvalue problem. The convergence and the validation of the proposed theoretical numerical model are performed to demonstrate the efficacy of the model.

A New Method of Phase Transformation (새로운 위상변성 방법)

  • Sang Se Oh
    • 전기의세계
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    • v.13 no.3
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    • pp.38-41
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    • 1964
  • This thesis is aimed to obtain efficiently economically any desired phases and single phase transformer without unbalance by using only a new transformer, applying the theory of rotating magnetic field. The brief construction and principle is as floow: two pieces of similar ring cores, triangular cores or polygonal cores are located on the upper and lower sides with equidistance. And the some number of similar leg cores, shaped a square-pillar or a sylinder, are arranged at equidistant of the core section. Ring windings or polyphase windings of AC machines are adopted as a winding method on the upper and lower cores. Three phase AC is applied to the primary windings on these cores so that the rotating magnetic field is induced on the cores and this magnetic fluxes pass through each of the secondary windings on the leg-cores with some difference in time.

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Transversely isotropic thin circular plate with multi-dual-phase lag heat transfer

  • Lata, Parveen;Kaur, Iqbal;Singh, Kulvinder
    • Steel and Composite Structures
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    • v.35 no.3
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    • pp.343-351
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    • 2020
  • The present research deals with the multi-dual-phase-lags thermoelasticity theory for thermoelastic behavior of transversely isotropic thermoelastic thin circular plate The Laplace and Hankel transform techniques have been used to find the solution of the problem. The displacement components, stress components, and conductive temperature distribution are computed in the transformed domain with the radial distance and further determined in the physical domain using numerical inversion techniques. The effect of rotation and two temperature are depicted graphically on the resulting quantities.

Using Central Manifold Theorem in the Analysis of Master-Slave Synchronization Networks

  • Castilho, Jose-Roberto;Carlos Nehemy;Alves, Luiz-Henrique
    • Journal of Communications and Networks
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    • v.6 no.3
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    • pp.197-202
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    • 2004
  • This work presents a stability analysis of the synchronous state for one-way master-slave time distribution networks with single star topology. Using bifurcation theory, the dynamical behavior of second-order phase-locked loops employed to extract the synchronous state in each node is analyzed in function of the constitutive parameters. Two usual inputs, the step and the ramp phase perturbations, are supposed to appear in the master node and, in each case, the existence and the stability of the synchronous state are studied. For parameter combinations resulting in non-hyperbolic synchronous states the linear approximation does not provide any information, even about the local behavior of the system. In this case, the center manifold theorem permits the construction of an equivalent vector field representing the asymptotic behavior of the original system in a local neighborhood of these points. Thus, the local stability can be determined.