• Title/Summary/Keyword: a constituent analysis

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An Theoretical study on Spalling Mechanism of Concrete (콘크리트 폭렬발생 메카니즘에 관한 이론적 고찰)

  • Kim, Hyung-Jun;Kim, Heung-Youl;Kim, Gyeong-Ok
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.422-427
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    • 2008
  • The major cause of Concrete Spalling at high temperatures can be divided into the Vapor Pressure Rising, caused by the increase in free water temperature within the concrete, and Pore Pressure Rising induced by the vapor moving into dense pores within the concrete. Although the occurrence of spalling within concrete caused by these pressure increases can be assessed experimentally, a close examination into Mechanistic influence against various spalling factors shall be carried out first by using Mathematical Modeling and Theoretical Equations. The Spalling Prospect Process by theoretical mechanism is expedited in order of the following; selection of heating condition (fire strength and flame heating direction), a selection of constituent elements, an analysis of heat transmission, an analysis of moisture movement, distribution of water content, an analysis of pore/vapor pressure, and assessment of spalling occurrence.

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Transient-Liquid-Phase Bonding of Fe-Base MA956 ODS Alloy (Fe기 MA956 산화물분산강화합금의 천이액상확산접합에 관한 연구)

  • 강지훈
    • Journal of Powder Materials
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    • v.2 no.1
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    • pp.53-62
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    • 1995
  • TLP(Transient-Liquid-Phase) bonding of Fe-base MA956 ODS alloy was performed. As insert metal a commercially available Ni-base alloy(MBF50) and an MA956 alloy with additive elements of 7wt% Si and 1wt% B were used. To confirm the idea that a concurrent use of MA956 powder with Insert metals can enhance the homogenization of constituent elements and thereby reduce the thickness of joint interface, MA956 powder was also inserted In a form of sheet. SEM observation and EDS analysis revealed that Cr-rich phase was formed in the bonded interface in initial stage of isothermal solidification during the bonding process, irrespective of kind of insert metals. Measurement of hardeness in the region of bonded interface and EDS analysis showed that a complete homogenization of composition could not be obtained especially in case of MBF50. Joints using either BSi insert metals only or BSi insert together with MA956 powder interlayer showed, however, a remarkable improvement in a compositional homogenization, even though a rapid grain growth in the bonded interface could not be hindered.

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Thermal Stability Analysis of 2-D Spacecraft Appendage (위성체 2-D 구조물의 열 안정성 해석)

  • 윤일성;송오섭;김규선
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.10a
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    • pp.99-104
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    • 2001
  • Thermally induced vibration response of solar array is investigated. The solar array model consists of composite thin walled beam and solar blanket, spreader bar. The composite thin walled beam incorporates a number of nonclassical effects of transverse shear, primary and secondary warping, rotary inertia and anisotropy of constituent materials. The solar blanket is a membrane subjected to uniform tension in the z direction. The spreader bar is a rigid member. A coupled thermal structure analysis that includes the effects of structural deformations on heating and temperature gradient is investigated. A stability criterion given in parameters for establishes the conditions for thermal flutter.

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Gardenia jasminoides extract and its constituent, genipin, inhibit activation of CD3/CD28 co-stimulated CD4+ T cells via ORAI1 channel

  • Kim, Hyun Jong;Nam, Yu Ran;Woo, JooHan;Kim, Woo Kyung;Nam, Joo Hyun
    • The Korean Journal of Physiology and Pharmacology
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    • v.24 no.4
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    • pp.363-372
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    • 2020
  • Gardenia jasminoides (GJ) is a widely used herbal medicine with anti-inflammatory properties, but its effects on the ORAI1 channel, which is important in generating intracellular calcium signaling for T cell activation, remain unknown. In this study, we investigated whether 70% ethanolic GJ extract (GJEtOH) and its subsequent fractions inhibit ORAI1 and determined which constituents contributed to this effect. Whole-cell patch clamp analysis revealed that GJEtOH (64.7% ± 3.83% inhibition at 0.1 mg/ml) and all its fractions showed inhibitory effects on the ORAI1 channel. Among the GJ fractions, the hexane fraction (GJHEX, 66.8% ± 9.95% at 0.1 mg/ml) had the most potent inhibitory effects in hORAI1-hSTIM1 co-transfected HEK293T cells. Chemical constituent analysis revealed that the strong ORAI1 inhibitory effect of GJHEX was due to linoleic acid, and in other fractions, we found that genipin inhibited ORAI1. Genipin significantly inhibited IORAI1 and interleukin-2 production in CD3/CD28-stimulated Jurkat T lymphocytes by 35.9% ± 3.02% and 54.7% ± 1.32% at 30 μM, respectively. Furthermore, the same genipin concentration inhibited the proliferation of human primary CD4+ T lymphocytes stimulated with CD3/CD28 antibodies by 54.9% ± 8.22%, as evaluated by carboxyfluorescein succinimidyl ester assay. Our findings suggest that genipin may be one of the active components of GJ responsible for T cell suppression, which is partially mediated by activation of the ORAI1 channel. This study helps us understand the mechanisms of GJ in the treatment of inflammatory diseases.

Flavonoidal constituent in Korean Lactuca dentata Makino (한국산 씀바귀의 Flavonoid 성분에 관한 연구)

  • Chung, Kang-Hyun;Yoon, Kwang-Ro;Kim, Jun-Pyong
    • Journal of the Korean Society of Food Culture
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    • v.9 no.2
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    • pp.131-136
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    • 1994
  • The ethylacetate extract of Lactuca dentata Makino showed 6 flavonoidal components as detected by ferric chloride solution. The flavonoidal constituent of Lactuca dentata Makino was isolated and purified by the series of column chromatography. The chemical structure of one of the flavonoidal component named as compound E was identified by UV, IR and NMR spectrometry. The melting point range of compound E was $249.5^{\circ}C-251^{\circ}C$. The UV and IR spectra of purified compound E, and its genin were measured with the various shifting agents. The results of UV analysis showed the free state of hydroxy group at 3rd and 4th carbon and binding of sugar at the 7th carbon of compound. The sugar bound to the compound E was identified as glucose by TLC. The IR spectrum showed the presense of hydroxy group, conjugated carbonyl group and aromatic group. The analysis of NMR spectrum was done to the purified compound and its derivatives. The chemical shifts against hydrogen atom, hydroxy group, and the moiety of luteolin were observed in the NMR spectrum along with their position and number as well as type of sugar bound. The isolated and purified compound was identified as $luteolin-7-0-{\beta}-D-glucoside$.

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Analysis of Pattern Identification and Related Symptoms on Idiopathic Short Stature -Focusing on Traditional Chinese Medicine Literature- (특발성 저신장의 변증 유형 및 변증별 증상 분석 -중의학 논문을 중심으로-)

  • Lee, Boram;Kwon, Chan-Young;Jang, Soobin
    • The Journal of Pediatrics of Korean Medicine
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    • v.35 no.1
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    • pp.1-17
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    • 2021
  • Objectives We aimed to analyze traditional Chinese medicine (TCM) literatures in regards to the pattern identification and related symptoms of idiopathic short stature (ISS). Methods We searched relevant literatures published up to September 29, 2020 through three Chinese electronic databases. We performed frequency analysis of the selected studies by extracting information on pattern identification, clinical symptoms, and TCM treatments presenting pattern identification of ISS. Results Sixteen studies were included. Spleen deficiency, kidney deficiency, dual deficiency of spleen-kidney, and liver-kidney yin deficiency were frequently reported. Clinical symptoms of the spleen deficiency include sallow complexion, body constituent weakness, anorexia, lack of qi and no desire to speak, and loose stools. Herbal medicines (HMs) such as Sijunzi-tang were frequently reported. Clinical symptoms of the kidney deficiency include cold limb and fear of cold, soreness and weakness of waist and knees, and clear and long urine. HMs such as Bishendihuang-wan were frequently reported. Clinical symptoms of the dual deficiency of spleen-kidney include body constituent weakness, spirit lassitude and lack of strength, anorexia, soreness and weakness of waist and knees, and cold limb and fear of cold. HMs such as Sijunzi-tang plus Bishendihuang-wan were frequently reported. Clinical symptoms of the liver-kidney yin deficiency include tidal fever and night sweating, heat in the palms and soles, dizziness, and dry throat. HMs such as Liuweidihuang-wan were frequently reported. Conclusions This was the first study to analyze the frequency of pattern identification and related symptoms on ISS. In the future, a standardized Korean medicine pattern identification system should be established.

Thermo mechanical analysis of a ceramic coated piston used in a diesel engine

  • Buyukkaya, Ekrem;Cerit, Muhammet;Coban, Mehmet
    • Steel and Composite Structures
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    • v.21 no.2
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    • pp.429-442
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    • 2016
  • The aim of this paper is to determine temperature and stress distributions in a ceramic based on Partially Stabilized Zirconia coated steel piston crown by using plasma spraying for improving performance of a marine diesel engine. Effects of coating constituent and thickness on temperature and stress distributions were investigated including comparisons with results from an uncoated piston by means of finite element method namely ANSYS. Temperature developed at the coated surface is significantly higher than that of the uncoated piston. The maximum stress components occur between bond coat and adjacent ceramic layer. Provided that coating thickness is constant as 0.5 mm, when numbers of layers increase, magnitude of the normal stress decrease about 34.1% on the base metal surface according to uncoated piston, but the base metal surface temperature of the steel piston increase about 13.1%.

An Analysis of the Word-Final Cluster of the Syllable Structure (음절구조의 어말 자음군에 관한 분석)

  • Oh, Kwan-Young
    • English Language & Literature Teaching
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    • v.10 no.2
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    • pp.67-87
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    • 2004
  • The purpose of this paper is to show how the coda of a syllable and word-final clusters are represented in the English syllable structure. Previous theories on the syllable assume that there is only one segment in the coda position. And, as we know, the theories that license only one segment in the coda make it difficult to syllabicate the word-final cluster appropriately when more than two segments in the word-final cluster are encountered. I considered three approaches: the previous syllable structure (Selkirk, 1982; Borowsky 1989), sonority sequencing (Giegerich, 1992; Roca, 1999) and feature analysis (Goldsmith, 1990), But, all the considered methods don't give us a satisfactory explanation regarding word-final clusters. Finally, I will suggest a modified syllable representation as an alternative by placing two different appendixes under the Phonological Word which forms a constituent above the syllable node. From this it is possible to explain the former problematic word-final clusters including morphological information asan inflectional suffix in the structure.

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Bending analysis of FGM plates using a sinusoidal shear deformation theory

  • Hadji, Lazreg;Zouatnia, Nafissa;Kassoul, Amar
    • Wind and Structures
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    • v.23 no.6
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    • pp.543-558
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    • 2016
  • The response of functionally graded ceramic-metal plates is investigated using theoretical formulation, Navier's solutions, and a new displacement based on the high-order shear deformation theory are presented for static analysis of functionally graded plates. The theory accounts for a quadratic variation of the transverse shear strains across the thickness, and satisfies the zero traction boundary conditions on the top and bottom surfaces of the plate without using shear correction factors. The plates are assumed to have isotropic, two-constituent material distribution through the thickness, and the modulus of elasticity of the plate is assumed to vary according to a power-law distribution in terms of the volume fractions of the constituents. Numerical results of the new refined plate theory are presented to show the effect of the material distribution on the deflections, stresses and fundamental frequencies. It can be concluded that the proposed theory is accurate and simple in solving the static and free vibration behavior of functionally graded plates.

Dynamic Analysis of Viscoelastic Composite Thin-Walled Blade Structures (점탄성-복합재 박판 블레이드 구조물의 진동 해석)

  • Shin, Jae-Hyun;Na, Sung-Soo;Park, Chul-Hue
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1684-1689
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    • 2003
  • This paper concerns the analytical modeling and dynamic analysis of advanced cantilevered blade structure implemented by a dual approach based on structural tailoring and viscoelastic materials technology. Whereas structural tailoring uses the directionality properties of advanced composite materials, the passive materials technology exploits the damping capabilities of viscoelastic material(VEM) embedded into the host structure. The structure is modeled as a composite thin-walled beam incorporating a number of nonclassical features such as transverse shear, secondary warping, anisotropy of constituent materials, and rotary inertias. The case of VEM spreaded over the entire span of the structure is considered. The displayed numerical results provide a comprehensive picture of the synergisitic implications of the application of both techniques, namely, the tailoring and damping technology on vibration response of thin-walled beam structure exposed to external time-dependent excitations.

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