• Title/Summary/Keyword: Self-formation

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Regulation of Star Formation Rates in Multiphase Galactic Disks: Numerical Tests of the Thermal/Dynamical Equilibrium Model

  • Kim, Chang-Goo;Kim, Woong-Tae;Ostriker, Eve C.
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.74.1-74.1
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    • 2010
  • Using two-dimensional numerical hydrodynamic simulations, we investigate the regulation of star ormation rates in turbulent, multiphase, galactic gaseous disks. Our simulation domain is xisymmetric, and local in the radial direction and global in the vertical direction. Our models nclude galactic rotation, vertical stratification, self-gravity, heating and cooling, and thermal onduction. Turbulence in our models is driven by momentum feedback from supernova events ccurring in localized dense regions formed by thermal and gravitational instabilities. Self-onsistent radiative heating, representing enhanced/reduced FUV photons from the star formation, s also taken into account. Evolution of our model disks is highly dynamic, but reaches a quasi-teady state. The disks are overall in effective hydrostatic equilibrium with the midplane thermal ressure set by the vertical gravity. The star formation rate is found to be proportional pproximately linearly to the midplane thermal pressure. These results are in good agreement with the predictions of a recent theory by Ostriker, McKee, and Leroy (2010) for the thermal/dynamic equilibrium model of star formation regulation.

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Core Formation in a Turbulent Molecular Cloud

  • Kim, Jong-Soo
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.106.2-106.2
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    • 2011
  • The two competing theories of star formation are based on turbulence and ambipoar diffusion. I will first briefly explain the two theories. There have been analytical (or semi-analytic) models, which estimate star formation rates in a turbulent cloud. Most of them are based on the log-normal density PDF (probability density function) of the turbulent cloud without self-gravity. I will first show that the core (star) formation rate can be increased significantly once self-gravity of a turbulence cloud is taken into account. I will then present the evolution of molecular line profiles of HCO+ and C18O toward a dense core that is forming inside a magnetized turbulent molecular cloud. Features of the profiles can be affected more significantly by coupled velocity and abundance structures in the outer region than those in the inner dense part of the core. During the evolution of the core, the asymmetry of line profiles easily changes from blue to red, and vice versa. Finally, I will introduce a method for incorporating ambipolar diffusion in the strong coupling approximation into a multidimensional magnetohydrodynamic code.

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A Study on the Formation Process of Saam Acupuncture Method (사암침법(舍岩鍼法) 처방 형성 과정 고찰)

  • Oh, Jun-Ho;Kim, Nam-Il;Cha, Wung-Seok
    • Korean Journal of Oriental Medicine
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    • v.15 no.2
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    • pp.33-37
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    • 2009
  • Objectives : The authors performed this study to further understand Saam acupuncture method in an aspect of formation process. Methods : We were finding Saam's idea in a preface of the book. And we analyzed Saam acupuncture patterns to understand their formation. Results & Conclusion : We assume that Saam acupuncture patterns has formed over time. We were able to split their patters into three phases. That is Primitive-phase, Basic-phase and Practical-phase. We think they are traces of Formation Process. In the first, Saam found DongHaeng-acupoints that have in common Five Element between the five viscera and acupoint. And then, he compounded other meridian's DongHeng-acupoints to control self meridian. Finally acupoints of self meridian were added.

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The Effect of Processing Parameters to Manufacture Self-healing Microcapsules for Composite Materials (복합재료의 자가 치료용 캡슐 제작시 공정 변수들의 영향)

  • Yoon, YoungKi;Yoon, HiSeak
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.4
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    • pp.135-141
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    • 2001
  • An experimental study to find the effect of processing parameters for self-healing microcapules is performed. These microcapsules can be applied to accomplish the healing of delamination damage in woven E-glass/epoxy composites. This paper introduces the self-healing concept and presents a method for solving the microcapsule size and shape. Additionally, processing parameters are varied during the formation of microcapsules and these capsules are observed through optical microscope. To obtain thermogravimetric(TG) curve for the manufactured microcapsules, TGA tests are executed. From these results, the best processing conditions for the formation of capsules are found as follows: (1) temperature of solution $ 50^{\circ}C$, (2) potential of hytdrogen(pH) 3.5ppm, and (3) agitation 500~600rpm.

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Nano-identification for the Cleavage of Disulfide Bond during the Self-Assembly Processes of Unsymmetric Dialkyl Disulfides on Au(111)

  • Noh, Jae-Geun
    • Bulletin of the Korean Chemical Society
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    • v.26 no.4
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    • pp.553-557
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    • 2005
  • The formation of striped phases of unsymmetric hexyl octadecyl disulfide ($CH_3(CH_2)_5SS(CH_2)_{17}CH_3$, HOD) and 1-hydroxyundecyl octadecyl disulfide ($CH_3(CH_2)_{17}SS(CH_2)_{11}$OH, HUOD) on Au(111) and graphite has been investigated by scanning tunneling microscopy (STM) to understand the self-assembly processes of dialkyl disulfides. STM imaging clearly shows the formation of striped phases having corrugation periodicities that are nearly consistent with the molecular length of alkanethiolate moieties formed after the S-S bond cleavage of dialkyl disulfide on a gold surface. On the other hand, self-assembled monolayers (SAMs) of dialkyl disulfides on a graphite surface displayed long-range, well-ordered monolayers with one striped pattern that shows periodicity as a function of molecular length via nondissociative adsorption. From a nonoscopic viewpoint, we have clearly demonstrated that dialkyl disulfide SAMs on gold form via S-S bond cleavage of disulfide.

Thermal and Dynamical Evolution of a Gaseous Medium and Star Formation in Disk Galaxies

  • Kim, Chang-Goo;Kim, Woong-Tae;Ostriker, Eve C.
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.54.1-54.1
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    • 2011
  • Formation of self-gravitating gas clouds and hence stars in galaxies is a consequence of both thermal and dynamical evolution of a gaseous medium. Using hydrodynamics simulations including cooling and heating explicitly, we follow simultaneously thermal and dynamical evolution of galactic gas disks to study dynamics and structures of galactic spiral shocks with thermal instability and regulation of the star formation rates (SFRs). We first perform one-dimensional simulations in direction perpendicular to spiral arms. The multiphase gas flows across the arm soon achieve a quasi-steady state characterized by transitions from warm to cold phases at the shock and from cold to warm phases in the postshock expansion zone, producing a substantial fraction of intermediate-temperature gas. Next, we allow a vertical degree of freedom to model vertically stratified disks. The shock front experiences unsteady flapping motions, driving a significant amount of random gas motions, and self-gravity promotes formation of bound clouds inside spiral arms. Finally, we include the star formation feedback in both mechanical (due to supernova explosion) and radiative (due to FUV heating by young stars) forms in the absence of spiral arms. At saturation, gravitationally bound clouds form via thermal and gravitational instabilities, which are compensated by disruption via supernova explosions. We find that the FUV heating regulates the SFRs when gas surface density is low, confirming the prediction of the thermal and dynamical equilibrium model of Ostriker et al. (2010) for star formation regulation.

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A self-consistent model for the formation and eruption of a solar prominence

  • Magara, Tetsuya
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.47.2-47.2
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    • 2021
  • The present study is focused on origins of the flow and magnetic structure involved in the formation and eruption of a solar prominence. To clarify them, we performed an MHD simulation based on the 3-dimensional emerging flux tube (3DEFT) model, in which self-consistent evolution of a flow and magnetic field passing freely through the solar surface was obtained by seamlessly connecting subsurface dynamics with surface dynamics. By analyzing Lagrangian displacements of magnetized plasma elements, we demonstrate the flow structure which is naturally incorporated to the magnetic structure of the prominence formed via dynamic interaction between the flow and magnetic field.

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A study on Chou Sun-Ae's spiritual formation process in light of Carl Jung's individuation (칼 융의 개성화 과정에 비추어 본 주선애의 영성형성과정 연구)

  • Hee-Young Kim
    • Journal of Christian Education in Korea
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    • v.74
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    • pp.159-188
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    • 2023
  • This study examines the process of Chou Sun-Ae's spiritual formation in the light of Carl Jung's conception of individuation. Spirituality is defined in different ways by different scholars, but most consider self-transcendence as a necessary element. This self-transcendence can occur in the relationship with self, with others, and with the transcendent. In the relationship with the self, it appears as self-objectification; with others, it is as moving toward others; and in the relationship with the transcendent, it moves toward the transcendent. Spirituality is closely related to individual identity, in that it surrounds and integrates life. Spiritual formation is thus closely related to Jung's concept of individuation, as this involves the separation of persona and ego, and shadow recognition which are closely related to the level of self-objectification. In addition, the withdrawal of shadow projection that occurs in individuation is closely related to moving toward others, in that it recognizes the shadow instead of blaming others, allowing one to look at others without prejudice. The fact that Jesus Christ is the symbol of the Self, the driving force of the individuation process, tells us that spirituality leading to a relationship with the transcendent God and Jung's theory are closely related to each other. Thus, if we examine the process of spiritual formation through the Jung's individuation process, we can better understand the psychodynamic dimension of spirituality. This article investigates the process of Chou Sun-Ae's spiritual formation through Jung's individuation process. Throughout her 98 years, Chou Sun-Ae experienced national pain and hardships, as well as personal adversity and difficulties; but through all of these hardships, conflicts, and difficult moments, she accomplished individualization. Therefore, by examining the spiritual formation through individuation in Chou Sun-Ae, I consider the direction of Christian spiritual education. In this study, three main characteristics of Chou Sun-Ae's spiritual formation can be identified. First, through a life of repentance, the identification between persona and ego can be weakened. Second, the ego develops, and individualization is achieved, through a new calling. Third, in shadow integration, the spiritual development comes to recognize Jesus Christ on the cross and achieve the process of sanctification. Investigating the direction of Christian spiritual education through Chou Sun-Ae's spiritual formation indicates that Christian spiritual education should harmonize vertical and horizontal relations and should develop an experience of the transcendent God in everyday life. By this means, the believer can achieve Self-realization and be a true Christian who practices love for God and love for neighbors.

Identity Formation and Self-Reflection Strategies in the Development of Apparel Design ePortfolios

  • Seifert, Christin;Chattaraman, Veena
    • Fashion, Industry and Education
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    • v.14 no.2
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    • pp.60-69
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    • 2016
  • Visual literacy, a key element of a design portfolio, is achieved by communicating a consistent visual aesthetic with respect to design elements, design principles and individual style. Yet, students often feel challenged in articulating their personal aesthetic or design philosophy in order to create a unifying design identity within a body of artifacts. This paper shares some best practices on overcoming this challenge through students' engagement in self-reflection and identity formation processes. The implemented innovative strategy in a senior-level portfolio development course for apparel designers involved four different phases: 1) one-on-one meetings to self-reflect on previous design work, 2) selection and revision of artifacts, 3) peer-review and critiques of revised portfolio artifacts, and 4) development of a final ePortfolio to showcase a unified design identity. It was evident that recording students' initial self-reflection in the form of a metacognitive oral report encouraged and motivated identity development in their portfolio. Further, students expressed their satisfaction in the ability to participate in the selection process of artifacts by self-reflecting about what they wanted to highlight about themselves and why. Overall, student outcomes from this strategy exceeded expectations and the portfolios developed were successful in creating a cohesive design identity.