• Title/Summary/Keyword: understandings

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Study on the Strategy of Numerical Modeling for Hybrid Combustion (하이브리드 연소의 수치 모델링 전략에 관한 연구)

  • Yoon, Changjin;Kim, Jinkon;Moon, Heejang
    • Journal of Aerospace System Engineering
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    • v.1 no.2
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    • pp.37-42
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    • 2007
  • This paper proposes a numerical modeling approach to simulate the hybrid combustion phenomena. From the physical understandings of hybrid combustion, the computational domain was separated into three regions: the solid fuel, gas phase reactive flow, and the interface between solid and fluid. Moreover, for the accurate calculation, computational grids for these regions was generated at every time step considering the instantaneous moving interface which are governed by the balance equations using thermal pyrolysis. In the domain of reactive flow, by virtue of diffusion flame structure, turbulent combustion modeling was introduced using either mixture fraction approach or mean reaction rate approach.

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Nonthermal Radiation from Supernova Remnant Shocks

  • Kang, Hyesung
    • Journal of Astronomy and Space Sciences
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    • v.30 no.3
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    • pp.133-140
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    • 2013
  • Most of high energy cosmic rays (CRs) are thought to be produced by diffusive shock acceleration (DSA) at supernova remnants (SNRs) within the Galaxy. Fortunately, nonthermal emissions from CR protons and electrons can provide direct observational evidence for such a model and place strong constraints on the complex nonlinear plasma processes in DSA theory. In this study we calculate the energy spectra of CR protons and electrons in Type Ia SNRs, using time-dependent DSA simulations that incorporate phenomenological models for some wave-particle interactions. We demonstrate that the time-dependent evolution of the self-amplified magnetic fields, Alfv$\acute{e}$nic drift, and escape of the highest energy particles affect the energy spectra of accelerated protons and electrons, and so resulting nonthermal radiation spectrum. Especially, the spectral cutoffs in X-ray and ${\gamma}$-ray emission spectra are regulated by the evolution of the highest energy particles, which are injected at the early phase of SNRs. Thus detailed understandings of nonlinear wave-particle interactions and time-dependent DSA simulations of SNRs are crucial in testing the SNR hypothesis for the origin of Galactic cosmic rays.

DNA methylation-based age prediction from various tissues and body fluids

  • Jung, Sang-Eun;Shin, Kyoung-Jin;Lee, Hwan Young
    • BMB Reports
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    • v.50 no.11
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    • pp.546-553
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    • 2017
  • Aging is a natural and gradual process in human life. It is influenced by heredity, environment, lifestyle, and disease. DNA methylation varies with age, and the ability to predict the age of donor using DNA from evidence materials at a crime scene is of considerable value in forensic investigations. Recently, many studies have reported age prediction models based on DNA methylation from various tissues and body fluids. Those models seem to be very promising because of their high prediction accuracies. In this review, the changes of age-associated DNA methylation and the age prediction models for various tissues and body fluids were examined, and then the applicability of the DNA methylation-based age prediction method to the forensic investigations was discussed. This will improve the understandings about DNA methylation markers and their potential to be used as biomarkers in the forensic field, as well as the clinical field.

Polymer brush: a promising grafting approach to scaffolds for tissue engineering

  • Kim, Woonjung;Jung, Jongjin
    • BMB Reports
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    • v.49 no.12
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    • pp.655-661
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    • 2016
  • Polymer brush is a soft material unit tethered covalently on the surface of scaffolds. It can induce functional and structural modification of a substrate's properties. Such surface coating approach has attracted special attentions in the fields of stem cell biology, tissue engineering, and regenerative medicine due to facile fabrication, usability of various polymers, extracellular matrix (ECM)-like structural features, and in vivo stability. Here, we summarized polymer brush-based grafting approaches comparing self-assembled monolayer (SAM)-based coating method, in addition to physico-chemical characterization techniques for surfaces such as wettability, stiffness/elasticity, roughness, and chemical composition that can affect cell adhesion, differentiation, and proliferation. We also reviewed recent advancements in cell biological applications of polymer brushes by focusing on stem cell differentiation and 3D supports/implants for tissue formation. Understanding cell behaviors on polymer brushes in the scale of nanometer length can contribute to systematic understandings of cellular responses at the interface of polymers and scaffolds and their simultaneous effects on cell behaviors for promising platform designs.

Critical Heat Flux in Uniformly Heated Rod Bundle Under Wide Range of System Pressures (광범위한 압력조건하에서 균일 가열 수직 봉다발에서의 임계열유속)

  • Moon, Sang-Ki;Chun, Se-Young;Choi, Ki-Yong
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.195-200
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    • 2001
  • An experimental study on critical heat flux (CHF) has been performed for water flow in a uniformly heated vertical 3 by 3 rod bundle under low flow and a wide range of pressure conditions. The objective of this study is to investigate the parametric trends of CHF with 3 by 3 rod bundle test section where three unheated rods exist. The general trends of the CHF are coincident with previous understandings. At low flow and system pressure above 3 MPa, some critical qualities are larger than 1.0 due to counter-current flow in test sections. Since there is a supply of water to the heated section from unheated section, the maximum CHFs at system pressure between 2 and 4 MPa are not shown.

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Relationship between Children's Korean Traditional Music Abilities and Multiple Intelligences (유아의 국악능력과 다중지능간의 관계)

  • Kim, Na-Lae;Kim, Jin-Kyoung
    • Korean Journal of Child Studies
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    • v.30 no.2
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    • pp.195-209
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    • 2009
  • This study analyzed aspects of multiple intelligences related to rhythm, melody, understanding and representation of traditional Korean music. Subjects were 60 4-to 6-years-old children. Instruments were the Children's Korean Traditional Music (KTM) Ability Test (Park 2006)and Korean Multiple Intelligence Development Assessment Scale-My Young Child (MIDAS-MYC, Shearer, 1996). Data were analyzed by correlations and t-test. Findings were that (1) average scores on KTM rhythm and understandings were higher than melody and representation. (2) Traditional rhythm ability correlated most with linguistic intelligence. (3) Multiple intelligences by representation ability for KTM differed significantly in Linguistic intelligence and relationships to Naturalist, Musical, Logical-mathematical, Interpersonal, and Bodily-Kinesthetic intelligences.

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A Mitochondrial Perspective of Chronic Obstructive Pulmonary Disease Pathogenesis

  • Kang, Min-Jong;Shadel, Gerald S.
    • Tuberculosis and Respiratory Diseases
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    • v.79 no.4
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    • pp.207-213
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    • 2016
  • Chronic obstructive pulmonary disease (COPD) encompasses several clinical syndromes, most notably emphysema and chronic bronchitis. Most of the current treatments fail to attenuate severity and progression of the disease, thereby requiring better mechanistic understandings of pathogenesis to develop disease-modifying therapeutics. A number of theories on COPD pathogenesis have been promulgated wherein an increase in protease burden from chronic inflammation, exaggerated production of reactive oxygen species and the resulting oxidant injury, or superfluous cell death responses caused by enhanced cellular injury/damage were proposed as the culprit. These hypotheses are not mutually exclusive and together likely represent the multifaceted biological processes involved in COPD pathogenesis. Recent studies demonstrate that mitochondria are involved in innate immune signaling that plays important roles in cigarette smoke-induced inflammasome activation, pulmonary inflammation and tissue remodeling responses. These responses are reviewed herein and synthesized into a view of COPD pathogenesis whereby mitochondria play a central role.

Nursing Students' Observation Experiences During Operations (간호대학생의 수술관찰경험)

  • Kim, Mi Hee;Ha, Mi Ok
    • Journal of Korean Biological Nursing Science
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    • v.20 no.3
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    • pp.159-168
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    • 2018
  • Purpose: This study aimed to explore nursing students' experiences of observing surgeries in the operating room. Methods: The data were collected through written scripts of nursing students who participated in the operating room practice. Data were analyzed via qualitative content analysis. Results: Five themes emerged from the data: 'preparing with the thrilled hearts toward unknown area', 'drawing back in front of the mirror of realities', 'becoming an audience at a lifesaving orchestra', 'reaching a tipping point of knowing', and 'redrawing the trajectory of dream to be a nurse'. Conclusion: This study will prove helpful in describing their needs for systemic and emotional support. Findings indicated that major contributions of surgical observations to nursing students are more integrated understandings of nursing and the determinations of their career preferences.

Being healthy: Feeling healthy

  • Rastogi, Rajiv;Rastogi, Devesh
    • CELLMED
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    • v.8 no.1
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    • pp.1.1-1.4
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    • 2018
  • We have various understandings regarding health. Various medical systems being practiced in India other than conventional medicine i.e. Ayurveda, Yoga & Naturopathy, Unani, Siddha and Homoeopathy have defined health in their own way. From physical level up to spiritual level health has so many aspects which affect our overall personality. Some says that one who is established in self is healthy but some other says that in a perfect state of health physical homeostasis and mental equanimity occur in a balanced and healthy harmony. Another concept believes that health is normal and harmonious vibration of the elements and forces composing the human entity on the physical, mental, moral and spiritual planes of living in accordance with the constructive principles in Nature. At one place it is stated that good health means existence in harmony with evolution. The authors have reviewed various concepts and definitions of health and trying to conclude that health is a feeling which may be experienced only if you are really healthy. So, health is more and more balancing of all elements of your life in harmony with the universe.

The study on the Development of Menu Evaluation Mode1 in the Hotel (관광호텔 메뉴 평가모델 개발에 관한 연구)

  • 엄영호;이윤신
    • Culinary science and hospitality research
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    • v.6 no.3
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    • pp.307-328
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    • 2000
  • Menu is regarded as the main factor for management of hotel and restaurant. Menu design was affected by many factors, but there are some items should be considered carefully for development of menu, such as a good understandings of consumers' demand. considering of the regional characteristics, establishing of the exact target, and careful thinking of a unit cost. At last, the most important factor is careful evaluation of developed menu and it have to be continuously reformed by feed back of these factors. Food service industries should create an independent menu(including restaurant layout, consumer level, marketing and advertising) rather than copying other restaurant' menu. Also. we have to design an efficient menu with useful information through the best of menu.

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