• Title/Summary/Keyword: T-A formulation

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Out of plane vibrations of thin-walled curved beams considering shear flexibility

  • Cortinez, V.H.;Piovan, M.T.;Rossi, R.E.
    • Structural Engineering and Mechanics
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    • v.8 no.3
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    • pp.257-272
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    • 1999
  • In this paper a simple finite element is proposed for analyzing out of plane vibration of thin walled curved beams, with both open and closed sections, considering shear flexibility. The present element is obtained from a variational formulation governing the dynamics of a three-dimensional elastic body in which the stress tensor as well as the displacements are variationally independent. The element has two nodes with four degrees of freedom in each. Numerical examples for the first six frequencies are performed in order to assess the accuracy of the finite element formulation and to show the influence of the shear flexibility on the dynamics of the member.

Development and application of FEM/GEM program for evaluating formability of stamping dies (스탬핑 금형의 성형성 평가를 위한 유한요소/기하학힘평형법 프로그램 개발과 응용)

  • Kim, J.P.;Keum, Y.T.
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.3
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    • pp.80-93
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    • 1996
  • A 2-dimensional FEM/GEM program was developed under the plane strain assumption using linear line elements for analyzing stretch/draw forming operations of an arbitrarily shaped draw-die. FEM formulation adopted a new algorithm for solving force equilibrium as well as non-penetration condition simultaneously. Also, a rigid-viscoplastic material model with Hill's normal anisotropic yield condition and rate-sensitive hardening law is assumed, along with the Coulomb friction law in the contact regions. For the case of numerical divergence at nearly final forming stages, geometric force equilibrium method(GEM) is also introduced. The developed program was tested by simulating the forming processes of cylindrical punch/open die, and the drawing processes of automotive oilpan and hood inner panel in order to verify the usefulness and validity of FEM/GEM formulation. The numerical simulation verified the validity and robustness of developed program.

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Nodal method for handling irregularly deformed geometries in hexagonal lattice cores

  • Seongchan Kim;Han Gyu Joo;Hyun Chul Lee
    • Nuclear Engineering and Technology
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    • v.56 no.3
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    • pp.772-784
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    • 2024
  • The hexagonal nodal code RENUS has been enhanced to handle irregularly deformed hexagonal assemblies. The underlying RENUS methods involving triangle-based polynomial expansion nodal (T-PEN) and corner point balance (CPB) were extended in a way to use line and surface integrals of polynomials in a deformed hexagonal geometry. The nodal calculation is accelerated by the coarse mesh finite difference (CMFD) formulation extended to unstructured geometry. The accuracy of the unstructured nodal solution was evaluated for a group of 2D SFR core problems in which the assembly corner points are arbitrarily displaced. The RENUS results for the change in nuclear characteristics resulting from fuel deformation were compared with those of the reference McCARD Monte Carlo code. It turned out that the two solutions agree within 18 pcm in reactivity change and 0.46% in assembly power distribution change. These results demonstrate that the proposed unstructured nodal method can accurately model heterogeneous thermal expansion in hexagonal fueled cores.

Three Dimensional Correction Factors for the Added Mass Moment of Inertia of Ships in Torsional Vibration (선체(船體)비틂진동(振動)에 있어서의 부가관성(附加慣性)모우멘트 3차원수정계수(次元修正係數))

  • K.C.,Kim;H.S.,Lee
    • Bulletin of the Society of Naval Architects of Korea
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    • v.11 no.2
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    • pp.15-22
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    • 1974
  • As for the added mass moment of inertia of ships in torsional vibration, it seems that the works by T. Kumai[1,2] are the only systematic one available currently. The work[1] is for the calculation of the two dimensional correction factors with finitely-long elliptic cylinders as the mathematic model. In this work the authors recalculated the above factors, $J_{\tau}$, with the same mathematic model and the same problem formulation, and presented the numerical results in Fig. 1. The reason why the reinvestigation was done was that in Kumai's work he obtained the solutions of the Mathieu equations, which was derived from the problem formulation for the velocity potential, under the assumption that the dummy constant q involved in the equations was always far less than unity, whereas in fact it takes values within the region of $0<q{\leq}{\infty}$ in sequence. As a result the authors found two remarkable differences in general features of $J_{\tau}$(refer to Fg.3); one that the authors' numerical results are considerably higher than the results given in [2], and the other that for a given number of node those have properties of decreasing monotonically with increase of the beam-draft ratio while these rapidly decrease from a maximum value of near at B/T=2.00 with B/T becoming greater or less than ratio. It seems that the latter trend was resulted from the fact that the assumption of $q{\ll}1$ employed in [2] was more closely satisfied in the vicinity of B/T=2.00.

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Formulating Reduced-fat Sausages with Quinoa or Teff Flours: Effects on Emulsion Characteristics and Product Quality

  • Ozturk-Kerimoglu, Burcu;Kavusan, Hulya Serpil;Tabak, Damla;Serdaroglu, Meltem
    • Food Science of Animal Resources
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    • v.40 no.5
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    • pp.710-721
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    • 2020
  • This study dealt with the use of quinoa flour (QF) or teff flour (TF) as partial beef fat replacers in the formulation of emulsion-type sausages. A control (C) group was manufactured with 20% beef fat, while the other three groups were formulated with 10% beef fat plus 5% QF (Q), 5% TF (T), and 2.5% QF+2.5% TF (QT). Water-holding capacity of the emulsions was higher in Q (81.81%), T (82.20%), and QT (84.10%) samples than in C (64.83%) samples. Total expressible fluid and expressible fat were the lowest in Q and T samples, indicating the highest emulsion stability of those groups. Incorporation of QF and TF into formulations increased moisture and carbohydrate contents while decreased fat and energy values. Besides, the use of QF was effective to increase protein and dietary fiber contents. T sausages had lower luminosity (L) and higher yellowness (b) than C sausages, whilst Q sausages did not result in significant color changes. Higher cook yield values were recorded in Q (97.96%), T (98.21%), and QT (98.15%) samples compared with C (96.44%) samples. Inclusion of QF and TF to formulation led to lower hardness and gumminess, while utilization of TF was also effective to decrease chewiness. Consequently, healthier emulsified sausages were obtained by the inclusion of QF or TF that could decrease the fat content more than 50% without sacrificing overall quality, bringing advantages by quinoa over teff for increasing nutritional value and leading minimal modifications on color and texture.

Effect of Gongjindan, a Polyherbal Formula on the Pharmacokinetics Profiles of Sorafenib in Male SD Rats (1) - Single Oral Combination Treatment of Sorafenib 50mg/kg with Gongjindan 100mg/kg within 5min -

  • Kim, SeungMo;Lee, Chang Hyeong;Park, Soo Jin;Kang, Su Jin;Song, Chang Hyun;Han, Chang Hyun;Ku, Sae Kwang;Lee, Young Joon
    • Journal of Society of Preventive Korean Medicine
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    • v.18 no.2
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    • pp.89-100
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    • 2014
  • Objective : The co-administration effects of Gongjindan (GJD) on the pharmacokinetics (PK) of sorafenib were observed as a process of the comprehensive and integrative medicine. Methods : After sorafenib treatment, GJD was administered within 5 min. The plasma were collected at 30min before administration, 30min, 1, 2, 3, 4, 6, 8 and 24hrs after end of GJD treatment, and plasma concentrations of sorafenib were analyzed using LC-MS/MS methods. PK parameters of sorafenib ($T_{max}$, $C_{max}$, AUC, $t_{1/2}$ and $MRT_{inf}$) were analysis as compared with sorafenib single administered rats. Results : The absorption of sorafenib were significantly increased at 30min, 1, 6 and 6hrs after co-administration with GJD as compared with sorafenib single treated rats. Accordingly, the $AUC_{0-t}$ (47.20%) of sorafenib was significantly increased but $t_{1/2}$ (-30.63%) and $MRT_{inf}$ (-34.11%) in co-administered rats were non-significantly decreased. These findings are considered as direct evidences that GJD increased the oral bioavailability of sorafenib through increase of the absorption, when they co-administered within 5min. Conclusion : Based on the results, co-administration of GJD increased the oral bioavailability of sorafenib through increase of the gastrointestinal absorption. It is considered that the more detail pharmacokinetic studies should be tested to conclude the effects of GJD on the pharmacokinetics of sorafenib, when they were co-administered, like the effects after co-administration with reasonable intervals considering the $T_{max}$ of sorafenib (about 3.5hr-intervals) and after repeated co-administrations.Hence, concomitant uses of GJD with sorafenib may require close monitoring for potential drug interactions.

An Analyical Study for Estimating Passenger Car Equivalents of Heavy Vehicles (대형차의 승용차 환산계수의 산정을 위한 해석적 연구)

  • 박창호;윤항묵;전경수
    • Journal of Korean Society of Transportation
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    • v.8 no.2
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    • pp.99-107
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    • 1990
  • This research addresses the effect of heavy vehicles (especially trucks) in terms of passenger car Equivalents from a capacity viewpoint. A formulation that estimate PCE in this paper is derived by introducing appropriate headway measurements into Huber's general equation for PCEs. In this equation, PCE value is expressed in terms of headways for four different kinds of pairs; pairs of leading and following vehicles ; P-P, P-T, P-T, T-T. The mean value of headway for each case is estimated through the regression analysis. Finally, the approach used in this research was compared with macroscopic approach which analyzed a speed-density relationship to evaluate PCE.

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Analysis of Electromagnetic Field Characteristics of 30 KVA Superconducting Generator Using 3D FEM Program (3차원 유한요소 프로그램을 이용한 30 KVA 초전도발전기의 전자장 특성 해석)

  • Lee, Jong-Hyuk;Shin, Pan-Seok;Lee, Jae-Kun;Park, Do-Young
    • Proceedings of the KIEE Conference
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    • 1998.07a
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    • pp.250-253
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    • 1998
  • This paper has proposed a method to analyze a 30 KVA superconducting generator using 3-dimensional FEM program. 3 kinds of 3D formulation methods are employed such as scalar potential in core region, reduced scalar potential in air region and T-${\omega}$ formulation in stator coil region. As results of the simulation, various parameters of the generator have been analyzed like air gap flux density, induced voltage, inductance, etc.

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Pharmacokinetics of Acebrophylline Containing Double-layered Sustained Release Tablet in Mini Pigs (미니피그를 이용한 아세브로필린 이중정의 약동학적 평가 (아세브로필린 이중정 개발))

  • Kim, Kang Min;Ko, Chan Young;Kang, Jae Seon
    • YAKHAK HOEJI
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    • v.57 no.6
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    • pp.442-447
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    • 2013
  • The aim of the present study was to improve commercial twice-a-day Acebrophylline formulation to once-a-day new formulation to improve patient compliances. To develop the double-layered tablet, the sustained release layer was prepared using Eudragit$^{(R)}$ L100-55 and Carnauba wax. The sustained release layer has shown delayed release rates in pH 1.2 which comparable to that of performed in pH 6.8 buffer. In the comparative pharmacokinetic study with commercialized Surfolase$^{(R)}$, the present double-layered Acebrophylline tablet has shown similar pharmacokinetic parameters of AUC, $C_{max}$ and $T_{max}$ values.

Interspecies Comparison of the Oral Absorption of Itraconazole in Laboratory Animals

  • Yoo, Sun-Dong;Kang, Eun-Hee;Shin, Beom-Soo;Lee, Hun-Jun;Lee, Sang-Heon;Lee, Kang-Choon;Lee, Kyu-Hyun
    • Archives of Pharmacal Research
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    • v.25 no.3
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    • pp.387-391
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    • 2002
  • The oral absorption and disposition of itraconazole were studied in rats, rabbits and dogs. Serum levels of itraconazole and its active metabolite, hydroxyitraconazole, were determined by a validated HPLC method. The absorption of itraconazole was relatively rapid in rats and dogs but was slower in rabbits. The terminal elimination half-life ($T_{1/2,{\lambda}z}$), time to the peak concentration ($T_{max}$), dose and weight normalized area under the curve (AUC) and the peak concentration ($C_{max}$) of itraconazole found in the dog were comparable to those reported in humans. As in humans, the metabolite to parent drug AUC ratios in rats and dogs were greater than unity but was less in rabbits. The dog appears to be an appropriate animal model while the rat, not the rabbit, may be used as an alternative animal model in predicting the oral absorption of itraconazole in humans.