• Title/Summary/Keyword: Initial Condition

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Biodegradation of Trichloroethylene by Phenol-degrading Pseudomonas putida

  • Shin, Hyun-Jae;Lee, Moo-Yeal;Yang, Ji-Won
    • Journal of Microbiology and Biotechnology
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    • v.8 no.2
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    • pp.185-187
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    • 1998
  • Pseudomonas putida KCTC 2401 degrades 1,1, 2-trichloroethylene (TCE) using phenol as a cosubstrate. The initial TCE degradation rate decreased with the initial TCE concentration up to 20mg/l of TCE at $30^{\circ}C$ and pH 6.5. The initial degradation rate and total removal efficiency increased with inoculum size. The strain also degraded dichloroacetic acid, which was supposed to be a degradation by-product. Phenol monooxygenase apparently participates in the TCE degradation mechanism.

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Analysis of the two dimensional sheet debris flight equations: initial and final state

  • Scarabino, A.;Giacopinelli, P.
    • Wind and Structures
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    • v.13 no.2
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    • pp.109-125
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    • 2010
  • This work presents some analytical and numerical results of a dynamic analysis of the dimensionless 2-D sheet flight equations. Two empirical models for aerodynamic forces and moments are used and compared. Results show that the initial condition of rest is always unstable, and for long times three distinct flight regimes are possible, depending on the initial angle of attack, the Tachikawa number, Ta (in fact, the parameter chosen was its inverse, ${\Omega}$), and a mass ratio ${\Phi}$. The final orbits in the velocity space and their maximum kinetic energy are compared with a theoretical asymptotic state of the motion equations, and some design considerations are proposed.

Reliability and maximum transmission length analysis between adjacent optical solitons in nonlinear dispersive transmission materials (비선형 분산 광 전송 매질에 있어서 인접 광 솔리톤간의 신뢰도 및 최대 전송거리 분석)

  • 변승우;김종규;송재원
    • Electrical & Electronic Materials
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    • v.9 no.3
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    • pp.246-250
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    • 1996
  • In optical soliton transmission systems with nonlinear dispersive materials, which is utilized for ultra-long and high bit rate transmission, it is shown that the value of initial time difference between adjacent solitons is analyzed for optimum bit rate. The method is inducted by uncorrelation condition with minimum interaction forces in initial covariance coefficient between adjacent solitons. When the initial time difference is 6 times of soliton pulse width by the results, it is shown that the reliability is maintained with more than 90% within transmission length of soliton period. multiplied by 93.

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A Numerical Study on the Compression Wave Generated by the Train Entering a Tunnel (열차가 터널에 진입할 때 발생하는 압축파에 대한 수치해석)

  • Kim, Sa-Ryang
    • The KSFM Journal of Fluid Machinery
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    • v.9 no.6 s.39
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    • pp.17-21
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    • 2006
  • The numerical simulations on the train entering a tunnel were performed by solving unsteady axi-symmetric problems. In the case that 5th order velocity profile is used to reduce the effects of the pressure wave generated by the train starting abruptly, the effect of the initial distance between the train and the tunnel were examined. The impulsive start gives undesired pressure disturbances to the flow field including inside the tunnel. But 5th order velocity profile with initial distance more than 80 m gives much stable pressure variance in time, and pressure distribution inside the tunnel in space. The distance to the train reaches the highest running velocity from the start should be more than 80 m when the train speed is 350 km/h.

Impact Buckling Reliability Analysis of Stiffened Cylinder With Initial Geometric Imperfection (기하학적 초기형상결함을 갖는 보강 원통의 충격좌굴 신뢰성 해석)

  • 김두기
    • Journal of KSNVE
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    • v.6 no.6
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    • pp.735-747
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    • 1996
  • In this paper, buckling reliability analyses of stiffened cylinder with random initial geometric imperfection under axial impact load are performed by the combined response surface method. The effect of random geometric imperfection on the failure probability and reliability is recognized quantitatively. Buckling reliability decreases with the increase of mean value, cov of initial geometric imperfection under the same external load. Buckling probability under impact load is greater than those under static load with the same condition. From the probabilistic characteristics of imapct buckling load, relation between reliability index and safety parameter can be obtained in addition to the relation between load and reliability index. And those results can be used to determine the range of required safety parameter and acceptable imperfaction.

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A study on rib-web shaped ring forging using UBET (UBET를 이용한 리브-웨브형 링 단조에 관한 연구)

  • Kim, Y.H.;Bae, W.B.;Nam, K.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.5
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    • pp.134-142
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    • 1994
  • An upper bound elemental technique (UBET) is applied to predict variations of neutral plane and optimal position of the initial billet for rib-wep shaped ring forging. In the analysis, the neutral plane position and velocity fields are determined by minimizing the total power consump- tion with respect to chosen parameters. The degree of die-cavity filling by initial billet-position and the variations of neutral plane by friction condition are investigated. Experiments have been carried out with pure plasticine billets at room temperature. The theoretical predictions of the forging load and the flow pattern are in good agrement with the experimental results.

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Dynamic Response Analysis of a Heavy Duty Gas Turbine-Generator with Rigid Coupling Offset (고정 커플링의 오프셋을 갖는 발전용 가스터빈-발전기의 동적 응답해석)

  • Ha, Jin Woong;Jung, Dae Seok
    • The KSFM Journal of Fluid Machinery
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    • v.17 no.4
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    • pp.70-75
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    • 2014
  • In this paper a analysis method is presented to obtain the steady state dynamic response from the finite element based equations of a rotor-bearing system with initial deflection. The method has been applied to analyze the dynamic response of the two-shaft rotor-bearing system with rigid coupling offset in a heavy duty gas turbine-generator. Bumps in the dynamic response of each rotor system have been observed at each critical speed due to the effect of initial deflection for rigid coupling offset. And, the dynamic responses have been shown to reduce for operating condition changes from cold to hot.

Optimizing Conditions for the Growth and Bacteriocin Production of Lactococcus sp.HY 449 Usin Response Surface Methodology (반응표면 분석에 의한 Lactococcus sp. HY 449의 성장 및 Bacteriocin 생산의 최적화)

  • Kim, Sang-Kyo;Oh, Se-Jong;Lee, Sang-Jun;Baek, Young-Jin;Park, Yun-Hee
    • Microbiology and Biotechnology Letters
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    • v.22 no.5
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    • pp.522-530
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    • 1994
  • Bacteriocin-producing lactic acid bacteria, Lactococcus sp. HY 449, was isolated from dairy products. Using response surface methodology, the various concentrations of medium compo- nents (tryptone, glucose, yeast extract, tween 80, and initial pH) were tested to find the optimum conditions for maximum bacteriocin production and growth of Lactococcus sp. HY 449. Central composite design was used to control the concentrations of medium components in the experiment. Bacteriocin production and cell growth of Lactococcus sp. HY 449 were most affected by glucose and yeast extract. Estimated optimum growth conditions of Lactococcus sp. HY 449 were as follows; tryptone 1.08%, glucose 1.129%, yeast extract 0.674%, tween 80 0.11%, and initial pH 7.19. Also estimated optimum conditions for bacteriocin production were tryptone 0.937%, glucose 1.108%, yeast extract 0.163%, tween 80 0.09%, and initial pH 6.98.

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Application of Iterative Learning Control to 2-Mass Resonant System with Initial Position Error (위치 오차를 갖는 2관성 공진계에 대한 반복학습 제어의 적용에 관한 연구)

  • Lee, Hak-Seong
    • Proceedings of the KIEE Conference
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    • 2003.11b
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    • pp.307-310
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    • 2003
  • In this paper, an iterative learning control method is applied to suppress the vibration of a 2-mass system which has a flexible coupling between a load an a motor. More specifically, conditions for the load speed without vibration are derived based on the steady-state condition. And the desired motor position trajectory is synthesized based on the relation between the load and motor speed. Finally, a PD-type learning iterative control law is applied for the desired motor position trajectory. Since the learning law applied for the desired trajectory guarantees the perfect tracking performance, the resulting load speed shows no vibration. In order to handle the initial position error, the PD-type learning law is changed to PID-type and a weight function is added to suppress the residual vibration caused by the initial error. The simulation results show the effectiveness of the proposed learning method.

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The Buckling Characteristics of Single-Layer Latticed Domes with Initial Imperfection (초기불완전성을 고려한 단층래티스돔의 좌굴특성)

  • 권택진;한상을;이동우;주동현
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1996.04a
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    • pp.1-8
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    • 1996
  • Many studies showed that small imperfections can also have a considerable influence on the behaviour of structures. Especially, in Single-Layer Latticed Domes, initial imperfection occurred by human error and construction error is very important to the buckling load. The definition of imperfection is that a node of structure shifts from perfect condition. For example, in the case of truss structures, imperfections are represented by shifting the location of nodal points relative to the position in which they would be for a perfect structure. This paper uses Arc-length Method in nonlinear iteration analysis, choosing star dome, in which many studies have been accomplished, as a model. The results of analysis show that initial imperfection can reduce the buckling load of structures.

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