• 제목/요약/키워드: H-Beam

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Simulation of H-beam rolling process using FEM (FEM을 이용한 H형강 압연공정 해석)

  • Park, C.S.;Kim, J.M.;Woo, K.M.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.05a
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    • pp.419-422
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    • 2008
  • It is most important to design the roll pass in shape rolling process. However, roll pass design has been accomplished by experience and intuition of a skilled engineer up to now. And it has being produced throughout a lot of trial and error. Thus, in this study, we tried to analysis the rolling process of H-beam by using FEM program for the quantitative evaluation of the plastic deformation. It could be predicted that rolling load, torque, shape of cross section and distribution of effective strain each pass by the analysis of rolling from break down mill(2 Hi rolling) to finishing rolling(Universal rolling) considering the heat transfer.

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An Experimental Study on Load Bearing Capacity of Lattice Girder as a Steel Support in Tunnelling (터널 지보재로서 격자지보의 하중지지력에 관한 실험적 연구)

  • 유충식;배규진
    • Geotechnical Engineering
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    • v.13 no.4
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    • pp.163-176
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    • 1997
  • It has long been recognized that the H-beam steel rib has many shortcomings when used as a steel support in tunneling. One of the major shortcomings is the shotcrete shadow created behind H-beam flange which eventually reduces the load bearing capacity of shotcrete shell. In many European countries, plate girder as the H-beam steel rib has been replaced by lattice girder which has many advantages over the H-beam steel rib. Successful application of the lattice girder as a steel support requires a thorough investigation on the load bearing capacity of the lattice girder. Therefore, laboratory bending and compression tests were conducted on lattice girders with the aim of investigating the load bearing capacity of the lattice girders. The results of tests show that the load bearing capacity of laIn twice girders is higher than that of H-beams, which indicates that the lattice girder can be effectively used as a support in tunneling.

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The Effect of Cross Beam on the strength and Stiffness of the Frame in Shuttle Car for LMIT (LMTT용 Suhttle Car의 Frame 강도 및 강성에 미치는 Cross Beam의 영향)

  • Lim J. H.;Han G. J.;Lee K. S.;Han D. S.;Shim J. J.;Lee S. W.;Jeon Y. H.
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.11a
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    • pp.323-328
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    • 2004
  • According as the quantity of goods transported by ship is increasing about $7\%$ per year, a port environment is rapidly changing. To meet this situation successfully, the development of the next generation port loading and unloading system (LMTT) is studied. A Frame of shuttle car for LMTT(Linear Motor-based Transfer Technology) consist of three parts which are outer beam inner beam and cross boom. Outer boom supports a container and inner boom is a framework and cross boom reinforces outer and inner boom. In this study, we carried out the finite element analysis for the effect of cross boom on the strength and stiffness qf the frame according to the number if cross beam leading position of container, the distance ratio if inner boom from center.

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Development of Hybrid OCB Beam for the Long-span Building Structures (장경간 건축구조를 위한 하이브리드 OCB보의 개발)

  • Lee, Doo-Sung;Kim, Sang-Yeon;Kim, Tae-Kyun
    • Land and Housing Review
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    • v.6 no.3
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    • pp.129-138
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    • 2015
  • The building structure in Korea is planned to maximize the use of space in recent. The hybrid OCB(Optimized Composite Beam) beam is developed to take advantage of using the space. The OCB beam is composed of the steel H-beam section reinforced by open strands in negative moment zone and the pretensioned PSC concrete section in positive zone. Flexural behavior of typical architectural hybrid OCB beam section was investigated by F.E.M. The 15m, 20m, 30m OCB models were tested on nonlinear material and geometry under static loading system. Following results are obtained from the analysis; 1)The OCB beam develop initial flexural cracking over full service loading. 2)Overall deflections of OCB beam under the service loads are less than those of the allowable limits in KCI Code(2012). 3)The ultimate load capacity get over the nominal strength of the OCB main section. The OCB beam is verified of structural reliability from the finite element analysis.

MEVVA ion Source And Filtered Thin-Film Deposition System

  • Liu, A.D.;Zhang, H.X.;Zhang, T.H.;Zhang, X.Y.;Wu, X.Y.;Zhang, S.J.;Li, Q.
    • Journal of Korean Vacuum Science & Technology
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    • v.6 no.2
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    • pp.55-57
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    • 2002
  • Metal-vapor-vacuum-arc ion source is an ideal source for both high current metal ion implanter and high current plasma thin-film deposition systems. It uses the direct evaporation of metal from surface of cathode by vacuum arc to produce a very high flux of ion plasmas. The MEVVA ion source, the high-current metal-ion implanter and high-current magnetic-field-filtered plasma thin-film deposition systems developed in Beijing Normal University are introduced in this paper.

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Purification and Characterization of a ${\beta}$-Glucosidase from Aspergillus niger and Its Application in the Hydrolysis of Geniposide to Genipin

  • Gong, Guohong;Zheng, Zhiming;Liu, Hui;Wang, Li;Diao, Jinshan;Wang, Peng;Zhao, Genhai
    • Journal of Microbiology and Biotechnology
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    • v.24 no.6
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    • pp.788-794
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    • 2014
  • An extracellular ${\beta}$-glucosidase from Aspergillus niger Au0847 was purified to homogeneity by precipitation with ammonium sulfate, anion exchange, and gel filtration. The purified protein was composed of two subunits with molecular masses of 110 and 120 kDa. Au0847 ${\beta}$-glucosidase exhibited relatively high thermostability and pH stability, and its highest activity was obtained at $65^{\circ}C$ and pH 4.6, respectively. As a potential metalloprotein, its enzymatic activity was potently stimulated by manganese ion and DTT. The ${\beta}$-glucosidase displayed avid affinity and high catalytic efficiency for geniposide. Au0847 ${\beta}$-glucosidase has potential value as an industrial enzyme for the hydrolysis of geniposide to genipin.

Measurement of the excited Xe atoms density of matastable state$(1S_5)$ under various binary gas mixtures(Ne-Xe) by Laser Absorption Spectroscopy.

  • Lee, Jun-Ho;OH, P.Y.;Moon, M.W.;Ko, B.D.;Jeong, J.M.;Lee, H.J.;Choi, E.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1218-1220
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    • 2005
  • We have developed laser absorption spectroscopy system for the measurement of excited Xe atoms in micro-discharged AC-PDP plasma. In this study, we have measured the absorption signals for the $1S_5$ xenon metastable state in the PDP cell with the various gas mixtures of Ne-Xe(1%), Ne-Xe(4%) and Ne-Xe(10%) under fixed gas pressure of 350 Torr and the eletrode gap distance of 50um. It is found that the maximum excited xenon densities are $1.2^{\ast}10^{12}\;cm^{-3}$, $1.8^{\ast}10^{12}\;cm^{-3}$ and $2.7^{\ast}10^{12}cm^{-3}$ for gas mixtures of Ne-Xe(1%), Ne-Xe(4%) and Ne-Xe(10%) respectively, in this experiment.

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Beam Characteristics of Polychromatic Diffracted Neutrons Used for Prompt Gamma Activation Analysis

  • S. H. Byun;G. M. Sun;Park, H. D.
    • Nuclear Engineering and Technology
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    • v.34 no.1
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    • pp.30-41
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    • 2002
  • The neutron beam is fully characterized for the prompt gamma activation analysis facility at Hanaro in the Korea Atomic Energy Research Institute(KAERI). The facility uses thermal neutrons which are diffracted vertically from a horizontal beam port by a set of pyrolytic graphite(PG) crystals positioned at the Bragg angle of 45" Neutron spectra, neutron flux and Cd-ratio are determined for the three extraction modes of diffracted beam by means of the theoretical and experimental efforts. To obtain theoretical result, the reflectivity of pyrolytic graphite is calculated in the diffraction model for mosaic crystal and the angular divergence after diffraction by mosaic crystal is estimated from Monte Carlo simulation. The time-of-flight spectrometer and gold activation wire are used for measuring the neutron spectra. Both the calculated and measured spectra have proven that the unique feature of polychromatic beam obtained by PG crystals are useful for PGAA. The thermal neutron flux of 7.9$\times$107 n/cm$^2$s and the Cd-ratio of 266 for gold have been achieved at the sample position while the reactor operates at 24 MW The uniformity of beam flux is 12% in the central 1$\times$1 cm$^2$ area. Finally, the beam is briefly characterized by the effective velocity and temperature which are determined by measuring the prompt Y-ray spectra for thin and thick boron samples.ples.

Refining of Invar and Permalloy Fe-Ni Alloys by $Ar/Ar-H_2$ Plasma and Electron Beam Melting (Ar/Ar-$H_2$ 플라즈마 및 전자선 용해에 의한 인바 및 퍼멀로이 Fe-Ni 합금의 정련)

  • Park, Byung-Sam;Baik, Hong-Koo
    • Journal of Korea Foundry Society
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    • v.15 no.2
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    • pp.175-183
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    • 1995
  • It is difficult to remove such interstitial impurities as sulfur, oxygen, hydrogen and carbon in Fe-Ni alloys. Thermodynamic and kinetic studies were carried out on the behavior of hydrogen gas, oxygen gas, Si, Al and slag, and the reaction time by the $Ar/Ar-H_2$ plasma and electron beam melting. After the addition of Al, Si, they were melted by Ar plasma with reaction time changed. 80%Ni-Fe alloys showed a better deoxidation than 36%Ni-Fe alloys. At $Ar-H_2$ plasma melting, the deoxidation was significant. In the case of the electron beam melting, the residual oxygen was higher than in Ar plasma melting because electron beam melting temperature was lower than that of Ar plasma. For the decaburization, it was melted by $Ar-O_2$ plasma melting, which could remove effectively carbon by activated oxygen in plasma. We added slag to Fe-Ni alloys for the desulfurization. As the result of this experiments, the amount of residual sulfur was not changed according to the slag ratio and reaction time.

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