• Title/Summary/Keyword: core formula

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Study on core herbs and herbal prescriptions from Internal medicine on Spleen system in Korean Medicine (한방비계내과학 내 중요 본초 및 처방 분석 연구)

  • Kim, Anna
    • Herbal Formula Science
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    • v.30 no.3
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    • pp.145-154
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    • 2022
  • Objective : This study aims to study core herbs and formulas in Internal medicine on Spleen system, to enhance efficiency in teaching Internal medicine on Spleen system, Herbalogy, Formula science, and to increase integration of the courses. Methods : Frequency notion, which was generally used in previous studies, was used in this study along with network analysis. Results : Frequently used herbs, herbs with high centrality, frequently combined herbs and core formula were found in this study. The herb with the highest frequency and centrality was 'Citri Unshius Pericarpium', and 'Atractylodis Rhizoma Alba - Citri Unshius Pericarpium' was the most frequent herb combination. The results of network analysis showed a total of 5 herbal communities of combination. Conclusion : Core herbs were found based on the frequency notion, which is a traditional analysis method. Also, core herbs, herbal combinations, formulas that can that may be overlooked when using frequency notions were found by using network analysis. The results may lead to enhancing efficiency in the education of Internal medicine on Spleen system, Herbalogy, Formula science courses and the integration of courses.

Study on Applicability of Ultimate Strength Design Formula for Sandwich Panels - Application Cases of Double Hull Tanker Bottom Structures

  • Kim, Bong Ju
    • Journal of Ocean Engineering and Technology
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    • v.34 no.2
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    • pp.97-109
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    • 2020
  • In this study, ultimate strength characteristics of clamped sandwich panels with metal faces and an elastic isotropic core under combined in-plane compression and lateral pressure loads are investigated to verify the applicability of the ultimate strength design formula for ship structures. Alternative elastomer-cored steel sandwich panels are selected instead of the conventional bottom stiffened panels for a Suezmax-class tanker and then the ultimate strength characteristics of the selected sandwich panels are examined by using nonlinear finite element analysis. The change in the ultimate strength characteristics due to the change in the thickness of the face plate and core as well as the amplitude of lateral pressure are summarized and compared with the results obtained by using the ultimate strength design formula and nonlinear finite element analysis. The insights and conclusions developed in the present study will be useful for the design and development of applications for sandwich panels in double hull tanker structures.

Study on rectangular concrete-filled steel tubes with unequal wall thickness

  • Zhang, Yang;Yu, Chen-Jiang;Fu, Guang-Yuan;Chen, Bing;Zhao, She-Xu;Li, Si-Ping
    • Steel and Composite Structures
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    • v.22 no.5
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    • pp.1073-1084
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    • 2016
  • Rectangular concrete-filled steel tubular columns with unequal wall thickness were investigated in the paper. The physical centroid, the centroidal principal axes of inertia, and the section core were given. The generalized bending formula and the generalized eccentric compression formula were deduced, and the equation of the neutral axis was also provided. The two rectangular concrete-filled steel tubular stub specimens subjected to the compression load on the physical centroid and the geometric centroid respectively were tested to verify the theoretical formulas.

Mechanical behaviors of concrete-filled rectangular steel tubular under pure torsion

  • Ding, Fa-xing;Sheng, Shi-jing;Yu, Yu-jie;Yu, Zhi-wu
    • Steel and Composite Structures
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    • v.31 no.3
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    • pp.291-301
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    • 2019
  • Pure torsion loading conditions were not frequently occurred in practical engineering, but the torsional researches were important since it's the basis of mechanical property researches under complex loading. Then a 3D finite element model with precise material constitutive models was established, and the effectiveness was verified with test data. Parametric studies with varying factors as steel yield strength, concrete strength and sectional height-width ratio, were performed. Internal stress state and the interaction effect between encased steel tube and the core concrete were analyzed. Results indicated that due to the confinement effect between steel tube and core concrete, the torsional strength of CFT columns was greatly improved comparing to plain concrete columns. The steel ratio would greatly influence the torque share between the steel tube and the core concrete. Then the torsional strength calculation formulas for core concrete and the whole CFT column were proposed. The proposed formula could be simpler and easier to use with guaranteed accuracy. Related design codes were more conservative than the proposed formula, but the proposed formula presented more satisfactory agreement with experimental results.

A Study on Flexural Behaviors of Sandwich Composites with Facesheets of Unequal Thickness (면재 두께가 다른 샌드위치 복합재의 굽힘 거동 연구)

  • Shin, Kwang-Bok;Lee, Jae-Youl;Ryu, Bong-Jo;Lee, Sang-Jin
    • Journal of the Korean Society for Railway
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    • v.10 no.2 s.39
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    • pp.201-210
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    • 2007
  • Sandwich composites made of glass fabric epoxy facesheets with aluminum honeycomb core or balsa core is considered for the structural design of bodyshell of a Korean Low Floor Bus. Initially, in order to select the optimal facesheet and core materials in design stage, the flexural response of a sandwich composite is a critical importance. In this study, theoretical formula which could easily and quickly evaluate and obtain the flexural responses such as deflection and flexural stiffness of a sandwich composite subjected to external load was established. This theory could calculate the flexural responses of sandwich composites with narrow as well as wide width and with facesheets of unequal thickness, and also distinguish between the bending and shear effects of deflection. Finite element analysis using ANSYS V10.0 was used to offer the best elements for real sandwich composites, and flexural test according to ASTM C393 was conducted to compare with the results of theoretical formula and finite element analysis. The results show that the flexural responses of sandwich composites using proposed theoretical formula is in good agreement with those of experiment and finite element method.

An Improvement of Closed-Form Formula for Mutual Impedance Computation

  • Son, Trinh-Van;Hwang, Keum Cheol;Park, Joon-Young;Kim, Seon-Joo;Shin, Jae-Ho
    • Journal of electromagnetic engineering and science
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    • v.13 no.4
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    • pp.240-244
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    • 2013
  • In this paper, we present an improvement of a closed-form formula for mutual impedance computation. Depending on the center-to-center spacing between two rectangular microstrip patch antennas, the mutual impedance formula is separated into two parts. The formula based on synthetic asymptote and variable separation is utilized for spacings of more than 0.5 ${\lambda}_0$. When the spacing is less than 0.5 ${\lambda}_0$, an approximate formula is proposed to improve the computation for closely spaced elements. Simulation results are compared to computational results of mutual impedances and mutual coupling coefficients as functions of normalized center-to-center spacing in both E- and H-plane coupling configurations. A good agreement between simulation and computation is achieved.

Experimental study on a new type of assembly bolted end-plate connection

  • Li, Shufeng;Li, Qingning;Jiang, Haotian;Zhang, Hao;Yan, Lei;Jiang, Weishan
    • Steel and Composite Structures
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    • v.26 no.4
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    • pp.463-471
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    • 2018
  • The bolted end-plate beam-column connections have been widely used in steel structure and composite structure because of its excellent seismic performance. In this paper, the end-plate bolted connection is applied in the concrete structure, A new-type of fabricated beam-column connections with end-plates is presented, and steel plate hoop is used to replace stirrups in the node core area. To study the seismic behavior of the joint, seven specimens are tested by pseudo-static test. The experimental results show that the new type of assembly node has good ductility and energy dissipation capacity. Besides, under the restraint effect of the high-strength stirrup, the width of the web crack is effectively controlled. In addition, based on the analysis of the factors affecting the shear capacity of the node core area, the formula of shear capacity of the core area of the node is proposed, and the theoretical values of the formula are consistent with the experimental value.

Investigations of elastic vibration periods of tall reinforced concrete office buildings

  • Al-Balhawi, Ali;Zhang, Binsheng
    • Wind and Structures
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    • v.29 no.3
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    • pp.209-223
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    • 2019
  • The assessment of wind-induced vibration for tall reinforced concrete (RC) buildings requires the accurate estimation of their dynamic properties, e.g., the fundamental vibration periods and damping ratios. In this study, RC frame-shear wall systems designed under gravity and wind loadings have been evaluated by utilising 3D FE modelling incorporating eigen-analysis to obtain the elastic periods of vibration. The conducted parameters consist of the number of storeys, the plan aspect ratio (AR) of buildings, the core dimensions, the space efficiency (SE), and the leasing depth (LD) between the internal central core and outer frames. This analysis provides a reliable basis for further investigating the effects of these parameters and establishing new formulas for predicting the fundamental vibration periods by using regression analyses on the obtained results. The proposed constrained numerically based formula for vibration periods of tall RC frame-shear wall office buildings in terms of the height of buildings reasonably agrees with some cited formulas for vibration period from design codes and standards. However, the same proposed formula has a high discrepancy with other cited formulas from the rest of design codes and standards. Also, the proposed formula agrees well with some cited experimentally based formulas.

Evaluation of the Applicability of Existing Design Formula for Seismic Isolation to Nuclear Power Plants (원자력발전소 면진적용을 위한 기존 설계식의 적용성 검토)

  • Kim, Hyun-Uk
    • Journal of the Earthquake Engineering Society of Korea
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    • v.16 no.6
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    • pp.29-36
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    • 2012
  • Involved in a research for the application of seismic isolation to the nuclear industry, this study evaluates firstly the responses of seismic isolation system considering general ranges of structural period and damping ratio by using preliminary design formula. Secondly, coupling effects of input motions were evaluated to find out appropriate conditions of excitations and effect of the iteration for calculating yield displacement of lead core was also assessed in terms of response of a seismically isolated structure. Finally, the results of preliminary design calculation were compared with those of dynamic analysis and the propriety of the formula was evaluated and appropriate ranges of reduction factor were also suggested from the results.

Development of Controlled Release Oral Drug Delivery System by Membrane-Coating Method-I - Preparation and pharmaceutical evaluation of controlled release acetaminophen tablets-

  • Shim, Chang-Koo;Kim, Ki-Man;Kim, Young-Il;Kim, Chong-Kook
    • Archives of Pharmacal Research
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    • v.13 no.2
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    • pp.151-160
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    • 1990
  • In order to develop a controlled-release oral drug delivery system (DDS) which sustains the plasma acetaminophen (AAP) concentration for a certain period of time, microporous membrane-coated tablets were prepared and evaluated in vitro. Firstly, highly water-soluble core tablet of AAP were prepared with various formulations by wet granulation and compression technique. Then the core tablets were coated with polyvinychloride (PVC) in which micronized sucrose particles were dispersed. Effect of formula compositions of core tablets and coating suspensions on the pharmaceutical characteristics such as drug release kinetics and membrane stability of the coated tablets was investigated in vitro. AAP was released from the coated tablets as a zero-order rate in a pH-independent manner. This independency of AAP release to pH change from 1.2 to 7.2 is favorable for the controlled oral drug delivery, since it will produce a constant drug release in the stomach and intestine regardless of the pH change in the GI tract. Drug release could be extended upto 10 h according to the coating condition. The release rate could be controlled by changing the formula compositions of the core tablets and coating suspensions, coat weight per each tablet, and especially PVC/sucrose ratio and particle size of the sucrose in the coating suspension. The coated tablets prepared in this study had a fairly good pharmaceutical characteristics in vitro, however, overall evaluation of the coated tablet should await in vivo absorption study in man.

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