• Title/Summary/Keyword: analytical expression

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Slenderness limit for SSTT-confined HSC column

  • Khun, Ma Chau;Awang, Abdullah Zawawi;Omar, Wahid
    • Structural Engineering and Mechanics
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    • v.50 no.2
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    • pp.201-214
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    • 2014
  • Due to the confinement effects, Steel-Straps Tensioning Technique (SSTT) can significantly enhance the strength and ductility of high-strength concrete (HSC) members (Moghaddam et al. 2008). However, the enhancement especially in strength may result in slender member and more susceptible to instability (Jiang and Teng 2012a). This instability is particularly significant in HSC member as it inherent the brittle nature of the material (Galano et al. 2008). The current slenderness limit expression used in the design is mainly derived from the experiment and analysis results based on Normal strength concrete (NSC) column and therefore the direct application of these slenderness limit expressions to the HSC column is being questioned. Besides, a particular slenderness limit for the SSTT-confined HSC column which incorporated the pre-tensioned force and multilayers effects is not yet available. Hence, an analytical study was carried out in the view of developing a simple equation in order to determine the slenderness limit for HSC column confined with SSTT. Based on the analytical results, it was concluded that the existing slenderness limit expressions used in the design are appropriate for neither HSC columns nor SSTT-confined HSC columns. In this paper, a slenderness limit expression which has incorporated the SSTT-confinement effects is proposed. The proposed expression can also be applied to unconfined HSC columns.

Bond Analysis of Ribbed Reinforcing Bars

  • Park, Oan-Chul
    • KCI Concrete Journal
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    • v.13 no.2
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    • pp.19-25
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    • 2001
  • A simple expression to predict bond strength of reinforcing bars with rib deformation to the surrounding is derived for the case of splitting bond failure. Finite element analysis is used to model the confining behavior of concrete cover. The roles of the interfacial properties, specifically, the friction coefficient, cohesion, the relative rib area and the rib face angle are examined. Values of bond strength obtained using the analytical model are in good agreement with the bond test results from the previous studies. The analytical model provides insight into interfacial bond mechanisms and the effects of the key variables on the bond strength of deformed bars to concrete. Based on the comparison between the analytical results and the test results, the values of cohesion, coefficient of friction, and the effective rib face angle are proposed.

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Heat Transfer Optimization in a Tube with Circular-Sectored Fins (원관내 부채꼴 휜 주위에서의 열전달 최적화)

  • Yoo, Jae-Wook;Kim, Sung-Jin;Hyun, Jae-Min
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.57-64
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    • 2000
  • The present work investigates the heat transfer characteristics for laminar fully developed forced convection in an internally finned tube with axially uniform heat flux and peripherally uniform temperature through analytical models of convection in a porous medium. Using the Brinkman-extended Darcy flow model and the two equation model fur heat transfer, analytical solutions fur fluid flow and heat transfer are obtained and compared with the exact solution for fluid flow and the numerical solutions for conjugate heat transfer to validate the porous medium approach. Using the analytical solutions, parameters of engineering importance are identified and their effects on fluid flow and heat transfer are studied. Also, the expression fur total thermal resistance is derived from the analytical solutions and minimized in order to optimize the thermal performance of the internally finned tubes.

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Analytical Model for Breakdown Voltages of InP Diodes (InP 다이오드에서 항복전압의 해석적 모델)

  • Chung, Yong-Sung
    • 전자공학회논문지 IE
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    • v.44 no.1
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    • pp.10-14
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    • 2007
  • Analytical expression for breakdown voltages of InP diodes is induced by employing the effective ionization coefficient extracted from ionization coefficients for electron and hole in InP. The analytical results for breakdown voltage are compared with numerical and experimental results for the doping concentration, $N_D=6\times10^{14}cm^{-3}\sim3\times10^{17}cm^{-3}$. The analytical results show good agreement with the numerical data. Good fits with the experimental results are found for the breakdown voltages within 10% in error at each doping concentration.

Analytical solution for axisymmetric buckling of joined conical shells under axial compression

  • Kouchakzadeh, M.A.;Shakouri, M.
    • Structural Engineering and Mechanics
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    • v.54 no.4
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    • pp.649-664
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    • 2015
  • In this study, the authors present an analytical approach to find the axisymmetric buckling load of two joined isotropic conical shells under axial compression. The problem of two joined conical shells may be considered as the generalized form of joined cylindrical and conical shells with constant or stepped thicknesses. Thickness of each cone is constant; however it may be different from the thickness of the other cone. The boundary conditions are assumed to be simply supported with rigid rings. The governing equations for the conical shells are obtained and solved with an analytical approach. A simple closed-form expression is obtained for the buckling load of two joined truncated conical shells. Results are compared and validated with the numerical results of finite element method. The variation of buckling load with changes in the thickness and semi-vertex angles of the two cones is studied. Finally, application of the results in practical design and range of engineering validity are investigated.

Calculation of Winding Inductances for a Single-Phase Brushless DC Machine

  • Joo, Dae-Suk;Woo, Kyung-Il;Kim, Dae-Kyong
    • Journal of Magnetics
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    • v.17 no.3
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    • pp.196-199
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    • 2012
  • This paper presents the analytical calculation of winding inductance for a single-phase brushless DC machine based on the magnetic circuit concept. The machine is used in the low power range of applications, such as ventilation fans, due to its simplicity and low cost. Since flux linkage is proportional to inductance, the calculation of winding inductance is of central importance. By comparison with experimental and analytical values, it is shown that proposed analytical expression is able to effectively predict the winding inductance of single-phase brushless DC machines at the design stage.

Rotational State Distribution of NO after Collisions with Fast Hydrogen Atom

  • Kim, Yu Hang;David A. Micha
    • Bulletin of the Korean Chemical Society
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    • v.16 no.5
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    • pp.436-438
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    • 1995
  • Based on the collisional time-correlation function approach a general analytical expression has been derived for the double differential cross-section with respect to the scattering angle and the final rotational energy, which can be applied to molecules with non-zero electronic orbital angular momentum after collision with fast hydrogen atoms. By integrating this expression another very simple expression, which gives the final rotational distribution as a function of the rotational quantum number, has also been derived. When this expression is applied to NO(2Π1/2, v'=1) and NO(2Π3/2, v'=1, 2, 3), it can reproduce the experimental rotational distribution after collision with fast H atom very well. The average rotational quantum number and average rotational energy using this expression are also in good agreement with those deduced from the experimental distributions.

Facile and Rapid Glycosylation Monitoring of Therapeutic Antibodies Through Intact Protein Analysis

  • Oh, Myung Jin;Seo, Nari;Seo, JungA;Kim, Ga Hyeon;An, Hyun Joo
    • Mass Spectrometry Letters
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    • v.12 no.3
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    • pp.85-92
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    • 2021
  • The therapeutic antibody drug market has experienced explosive growth as mAbs become the main therapeutic modality for a variety of diseases. Characterization of glycosylation that directly affects the efficacy and safety of therapeutic monoclonal antibodies (mAbs) is critical for therapeutics development, bioprocess system optimization, lot release, and comparability evaluation. The LC/MS approach has been widely used to structurally characterize mAbs, and recently attempts have been made to obtain comprehensive information on the primary structure and post-translational modifications (PTMs) of mAbs through intact protein analysis. In this study, we performed state-of-the-art LC/MS based intact protein analysis to readily identify and characterize glycoforms of various mAbs. Different glycoforms of mAbs produced in different expression cell lines including CHO, SP2/0 and HEK cells were monitored and compared. In addition, the comparability of protein molecular weight, glycoform pattern, and relative abundances of glycoforms between the commercialized trastuzumab biosimilar and the original product was determined in detail using the given platform. Intact mAb analysis allowed us to gain insight into the overall mAb structure, including the complexity and diversity of glycosylation. Furthermore, our analytical platform with high reproducibility is expected to be widely used for biopharmaceutical characterization required at all stages of drug development and manufacturing.

The design of reinforced concrete beams for shear in current practice: A new analytical model

  • Londhe, R.S.
    • Structural Engineering and Mechanics
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    • v.31 no.2
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    • pp.225-235
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    • 2009
  • The present paper reviews the shear design (of reinforced concrete beam) provisions of four different national codes and proposes a new but simplified shear strength empirical expression, incorporating variables such as compressive strength of concrete, percentage of longitudinal and vertical steel/s, depth of beam in terms of shear span-to-depth ratio, for reinforced concrete (RC) beams without shear reinforcement. The expression is based on the experimental investigation on RC beams without shear reinforcement. Further, the comparisons of shear design provisions of four National codes viz.: (i) IS 456-2000, (iii) BS 8110-1997, (iv) ACI 318-2002 (v) EuroCode-2-2002 and the proposed expression for the prediction of shear capacity of normal beam/s, have been made by solving a numerical example. The results of the numerical example worked out suggest that there is need for revision in the shear design procedure of different codes. Also, the proposed expression is less conservative among the IS, BS & Eurocode.

Analytical method for the out-of-plane buckling of the jib system with middle strut

  • Wang, T.F.;Lu, N.L.;Lan, P.
    • Steel and Composite Structures
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    • v.21 no.5
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    • pp.963-980
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    • 2016
  • The jib system with middle strut is widely used to achieve the large arm length in the large scale tower crane and the deployability in the mobile construction crane. In this paper, an analytical solution for the out-of-plane buckling of the jib system with middle strut is proposed. To obtain the analytical expression of the buckling characteristic equation, the method of differential equation was adopted by establishing the bending and torsional differential equation of the jib system under the instability critical state. Compared with the numerical solutions of the finite element software ANSYS, the analytical results in this work agree well with them. Therefore, the correctness of the results in this work can be confirmed. Then the influences of the lateral stiffness of the cable fixed joint, the dip angle of the strut, the inertia moment of the strut, and the horizontal position of the cable fixed joint on the out-of-plane buckling behavior of the jib system were investigated.