• Title/Summary/Keyword: R. C. element

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Comparison Study for Domestic Coal and Material Characteristics of Coal from the Shipwreck of Koryo Dynasty (고려시대 선체출토 석탄의 재료학적 특성 및 국산 석탄과의 비교 연구)

  • Lee, JangJon;Park, SukWhan;Lim, SungTae;Han, MinSu
    • Journal of Conservation Science
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    • v.29 no.4
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    • pp.345-354
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    • 2013
  • This study analyses geochemistrical, microscopic, mineralogical characteristics of coals which have been collected from in and out of the shipwreck No 1 of Mado island during underwater excavation in Taean. The result from mineralogical and geochemical analysis reveals that the specific gravity of the coals is $1.28g/cm^3$. Considering that coals contains 10% mineral of it and the specific gravity of the pure is $1.15g/cm^3$, it is believed that the collected coals would be lignite or biturminous coal. The X-ray diffraction analysis which displays the peak of $2{\theta}$ is 20~25C degree, proves that the collected coals would be categorised as low rank coal. The collected coals is composed of: 93%-94%(93.5%) of vitrinite maceral group, 5%-6%(5.5%) of exinite maceral group, and 1% of inertinite maceral group. In addition, the average of reflection rate is $R_{mean}$: 0.627 showing that it would be either high volatile bituminous C coal or sub-bituminous C coal. Such result confirms that the coal is sub-bituminous C or high volatile bituminous C coal in accordance with the U.S Bureau of Mine(USBM) classification system. The element analysis reveals that the coal is the coking coal which is grouped as the bituminous coal. Comparative analysis between the coals of Mado Shipwreck No 1 and domestic coals shows that the coals of Mado Shipwreck is similar to the bituminous coal used in the area of Janggi in Pohang city.

The Inhibitory Effects of Nelumbo nucifera Gaertner Extract on Melanogenesis (연자육 추출물의 멜라닌 합성 저해효과)

  • Lee, Jun Young;Im, Kyung Ran;Jung, Taek Kyu;Yoon, Kyung-Sup
    • KSBB Journal
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    • v.28 no.2
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    • pp.137-145
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    • 2013
  • In order to develop new skin whitening agents, we prepared the $CH_2Cl_2$ layer (NGC) and BuOH layer (NGB) of 75% EtOH extract of the Nelumbinis nucifera Gaertner. We measured their tyrosinase inhibitory activity in vitro and melanin synthesis inhibitory activity in B16-F1 melanoma cells. They did not show inhibitory activity against mushroom tyrosinase but showed melanin synthesis inhibitory activity in a dose-dependent manner. In a melanin synthesis inhibition assay, NGC and NGB suppressed melanin production up to 52% and 46% at a concentration of $100{\mu}g/mL$, respectively. To elucidate the mechanism of the inhibitory effects of NGC and NGB on melanogenesis, we measured the expression of melanogenesis-related proteins by western blot assay. As a result, NGC suppressed the expression of tyrosinase, tyrosinase related protein 1 (TRP-1), tyrosinase related protein 2 (TRP-2), phosphorylated cAMP responsive element binding (p-CREB) protein, and microphthalmia associated transcription factor (MITF). And NGB inhibited the protein expression of tyrosinase and MITF, but had no significant effect on TRP-1, TRP-2, and p-CREB expression. Moreover, NGB increased the expression of phosphorylated extracellular signal-regulated kinase (p-ERK). In addition, we examined the inhibitory effect on the glycosylation of tyrosinase. As a result, NGC and NGB inhibited the activity of ${\alpha}$-glucosidase in vitro and the glycosylation of tyrosinase in B16-F1 melanoma cells. From these results, we concluded that NGC and NGB could be used as active ingredients for skin whitening.

Numerical analysis of partially fire protected composite slabs

  • Zaharia, R.;Vulcu, C.;Vassart, O.;Gernay, T.;Franssen, J.M.
    • Steel and Composite Structures
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    • v.14 no.1
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    • pp.21-39
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    • 2013
  • The paper presents a numerical investigation, done with the computer program SAFIR, in order to obtain simpler finite element models for representing the behaviour of the partially protected composite steel concrete slabs in fire situations, considering the membrane action. Appropriate understanding and modelling of the particular behaviour of composite slabs allows a safe approach, but also substantial savings on the thermal insulation that has to be applied on the underlying steel structure. The influence of some critical parameters on the behaviour and fire resistance of composite slabs such as the amount of reinforcing steel, the thickness of the slab and the edge conditions is also highlighted. The results of the numerical analyses are compared with the results of three full scale fire tests on composite slabs that have been performed in recent years.

Expressed Sequence Tags of the Wheat-rye Translocation Line Possessing 2BS/2RL

  • Jang, Cheol-Seong;Hong, Byung-Hee;Seo, Yong-Weon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.44 no.3
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    • pp.302-307
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    • 1999
  • Hamlet (PI549276) possessing 2RL was obtained by cross between a wheat cultivar ND7532 (Froid/Centurk) and a rye cultivar Chaupon. Chaupon was known to have resistant gene to biotype L of Hessian fly [Mayetiola destructor (Say)] larvae. The wheat-rye translocation line (Coker797*4/Hamlet) was also known to be resistant to biotype L of Hessian fly larvae. We analysed a set of 96 ESTs from the wheat-rye translocation line (2BS/2RL). ESTs were classified by various physiological processings, such as primary metabolism, secondary metabolism, transcription, translation, transport, signal transduction, defense, transposable element, and others. Three sequences encoding thioredoxin peroxidase, 26S rRNA, and rubisco small subunits were homologous to registered genes in rye. Although limited number of clones were used to develop ESTs, these clones and their sequence information may be useful for researchers studying general physiology and molecular biology on the translocation line.

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2-ENGELIZER SUBGROUP OF A 2-ENGEL TRANSITIVE GROUPS

  • Moghaddam, Mohammad Reza R.;Rostamyari, Mohammad Amin
    • Bulletin of the Korean Mathematical Society
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    • v.53 no.3
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    • pp.657-665
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    • 2016
  • A general notion of ${\chi}$-transitive groups was introduced by C. Delizia et al. in [6], where ${\chi}$ is a class of groups. In [5], Ciobanu, Fine and Rosenberger studied the relationship among the notions of conjugately separated abelian, commutative transitive and fully residually ${\chi}$-groups. In this article we study the concept of 2-Engel transitive groups and among other results, its relationship with conjugately separated 2-Engel and fully residually ${\chi}$-groups are established. We also introduce the notion of 2-Engelizer of the element x in G and denote the set of all 2-Engelizers in G by $E^2(G)$. Then we construct the possible values of ${\mid}E^2(G){\mid}$.

OPTIMAL PREFORM DESGIN BY TRACING THE MATERIAL FLOW : APPLICATION TO PISTON FORGING

  • Hong J.T.;Lee S.R.;Park C.H.;Yang D.Y.;Chung W.J.;Park Y.B.;Kim Y.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.10b
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    • pp.143-146
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    • 2003
  • In this paper, a new preform design method is proposed to eliminate the excessive flash in metal forging process. After carrying out finite element simulation of the process with an initial billet, backward particle tracing is performed from the outlet of the flash. Then, the region which belongs to the flash is easily found .. The process is analyzed again with the redesigned billet which is removed that region the above mentioned region. The optimal preform shape which minimizes the amount of flash without changing the forgibility can be obtained in several iterations.

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Chord bearing capacity in long-span tubular trusses

  • Kozy, B.;Boyle, R.;Earls, C.J.
    • Steel and Composite Structures
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    • v.6 no.2
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    • pp.103-122
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    • 2006
  • The capacity of tubular truss chords subjected to concentrated reaction forces in the vicinity of the open end (i.e., the bearing region) is not directly treated by existing design specifications; although capacity equations are promulgated for related tubular joint configurations. The lack of direct treatment of bearing capacity in existing design specifications seems to represent an unsatisfactory situation given the fact that connections very often control the design of long-span tubular structures comprised of members with slender cross-sections. The case of the simple-span overhead highway sign truss is studied, in which the bearing reaction is applied near the chord end. The present research is aimed at assessing the validity of adapting existing specifications' capacity equations from related cases so as to be applicable in determining design capacity in tubular truss bearing regions. These modified capacity equations are subsequently used in comparisons with full-scale experimental results obtained from testing carried out at the University of Pittsburgh.

Process Analysis and Design in Forming of Bearing Rings by the FEM(II) (유한요소법을 활용한 궤도륜의 프레스 성형공정 설계(II))

  • 변상규;김태호;강범수;김완두
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1995.03a
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    • pp.19-30
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    • 1995
  • The analysis had been already completed to detect forming defects for the forming processes of C/R bearing rings. But some unpredicted problems were found through the experiments. So expert redesigned new forming processes to prevent the problems and new analysis was began according to the new processes to find faults for the processes. The forming processes consist of 1 for the outer ring. 6 inner ring. The thickness of metal sheet used is changed to 1.5mm from 1.6mm. Elasto-plastric finite element method is applied to involve the effect of spring back . The most representative alteration is forming of two predents to assist later forming . Thining and distribution of high residual stress are derived from the results of simulations. It is confirmed that the industry expert agree the possiblilty of defects dervied from the new FEM results.

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Seismic spectral acceleration assessment of masonry in-filled reinforced concrete buildings by a coefficient-based method

  • Su, R.K.L.;Lee, C.L.;Wang, Y.P.
    • Structural Engineering and Mechanics
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    • v.41 no.4
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    • pp.479-494
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    • 2012
  • This study explores a coefficient-based seismic capacity assessment method with a special emphasis on low-rise masonry in-filled (MI) reinforced concrete (RC) buildings subjected to earthquake motion. The coefficient-based method without requiring any complicated finite element analysis is a simplified procedure to assess the maximum spectral acceleration capacity of buildings. This paper first compares the fundamental periods of MI RC structures obtained, respectively, from experimental period data and empirical period-height formulas. The coefficient-based method for low-rise masonry buildings is then calibrated by the published experimental results obtained from shaking table tests. The comparison of the experimental and estimated results indicates that the simplified coefficient-based method can provide good approximations of the maximum spectral accelerations at peak loads of the low-rise masonry reinforced concrete buildings if a proper set of drift factors and initial fundamental vibration periods of structures are used.

Special Simulation Technique of Multi-Faced Long Bolt Forging Process (장축 다각 볼트 제조공정의 시뮬레이션 기술)

  • Han, S.S.;Eom, J.G.;Jang, S.M.;Lee, M.C.;Joun, M.S.;Kang, S.J.;Son, Y.R.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.05a
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    • pp.44-47
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    • 2009
  • In this paper, limitation of rigid-plastic finite element method caused from rigid-plasticity assumption and numerical problem is investigated in detail and a useful scheme is proposed to get rid of the plastic deformation in rigid or elastic region. A typical example of a possible long bar extrusion process is given, which may be impossible to simulate without using the proposed scheme. The scheme is successfully applied to simulating the long bolt forging processes.

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