• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.467-470
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• 2008

• Bulletin of the Korean Chemical Society
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• 제8권2호
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• pp.111-114
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• 1987

Temperature-dependent, solution EPR spectra of two mixed-valence copper(II)-copper(I) complexes have been simulated by using modified Bloch equations. The transition probability for the intramolecular electron transfer is determined from the simulation. The transition probabilities have been fitted to the Arrhenius equation to derive the activation energies. The transition probability also varies according to the solvent used.

• 전기학회논문지
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• 제56권3호
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• pp.577-582
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• 2007

The plasma display panel is an image expression display using gas discharge plasma. However, gas discharge characteristics vary with temperature as gas discharge is sensitive to temperature. The discharge time lag extends a lot in low temperature and it is known as the cause which hinders high speed addressing which is essential for the size enlargement of the panel. Accordingly this research aims at identifying the temperature-dependent discharge characteristic. The lower temperature becomes, the longer addressing discharge time lag becomes. Particularly the statistical time lag extends much in low temperature. The increasing of electric field shortens discharge time lag in low temperature. Also, when priming particles are sufficiently supplied, stable discharge can be performed regardless of the influence of temperature.

• Advances in aircraft and spacecraft science
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• 제5권1호
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• pp.141-164
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• 2018

In this paper, the thermal effect on buckling and free vibration characteristics of functionally graded (FG) size-dependent Timoshenko nanobeams subjected to an in-plane thermal loading are investigated by presenting a Navier type solution for the first time. Material properties of FG nanobeam are supposed to vary continuously along the thickness according to the power-law form and the material properties are assumed to be temperature-dependent. The small scale effect is taken into consideration based on nonlocal elasticity theory of Eringen. The nonlocal equations of motion are derived based on Timoshenko beam theory through Hamilton's principle and they are solved applying analytical solution. According to the numerical results, it is revealed that the proposed modeling can provide accurate frequency results of the FG nanobeams as compared to some cases in the literature. The detailed mathematical derivations are presented and numerical investigations are performed while the emphasis is placed on investigating the effect of the several parameters such as thermal effect, material distribution profile, small scale effects, aspect ratio and mode number on the critical buckling temperature and normalized natural frequencies of the temperature-dependent FG nanobeams in detail. It is explicitly shown that the thermal buckling and vibration behaviour of a FG nanobeams is significantly influenced by these effects. Numerical results are presented to serve as benchmarks for future analyses of FG nanobeams.

• Steel and Composite Structures
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• 제32권2호
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• pp.239-252
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• 2019

Since conical sandwich shells are important structures in the modern industries, in this paper, for the first time, vibration behavior of the truncated conical sandwich shells which include temperature dependent porous FG face sheets and temperature dependent homogeneous core in various thermal conditions are investigated. A high order theory of sandwich shells which modified by considering the flexibility of the core and nonlinear von Karman strains are utilized. Power law rule which modified by considering the two types of porosity volume fractions are applied to model the functionally graded materials. By utilizing the Hamilton's energy principle, and considering the in-plane and thermal stresses in the face-sheets and the core, the governing equations are obtained. A Galerkin procedure is used to solve the equations in a simply supported boundary condition. Uniform, linear and nonlinear temperature distributions are used to model the effect of the temperature changing in the sandwich shell. To verify the results of this study, they are compared with FEM results obtained by Abaqus software and for special cases with the results in literatures. Eigen frequencies variations are surveyed versus the temperature changing, geometrical effects, porosity, and some others in the numerical examples.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.373-374
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• 2009

본 연구는 온도의존적 장기팽창성을 갖는 MgO콘크리트 특성을 재령에 따라 온도 및 체적 변화를 고려한 콘크리트 구조물의 응력해석에 적용하기 위한 팽창모델을 비교 분석하여 적합한 모델을 제시하였다.

• Coupled systems mechanics
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• 제6권4호
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• pp.399-415
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• 2017

This paper deals with the nonlinear static deflections of functionally graded (FG) porous under thermal effect. Material properties vary in both position-dependent and temperature-dependent. The considered nonlinear problem is solved by using Total Lagrangian finite element method within two-dimensional (2-D) continuum model in the Newton-Raphson iteration method. In numerical examples, the effects of material distribution, porosity parameters, temperature rising on the nonlinear large deflections of FG beams are presented and discussed with porosity effects. Also, the effects of the different porosity models on the FG beams are investigated in temperature rising.

• 미생물학회지
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• 제55권3호
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• pp.181-190
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• 2019

대장균 세포분열 조절에 관여하는 DicA 단백질은 $37^{\circ}C$보다 $25^{\circ}C$에서 DNA에 더욱 잘 결합한다. 그러나 DicA 단백질의 온도의존적 DNA 결합에 대한 분자적 원인은 명확하지 않다. 본 연구에서는 DicA 단백질이 어떻게 DNA에 결합하며, 왜 온도 의존적 결합양상을 보이는지 알아보았다. In vivo DNA 결합 분석 결과 RovA나 SlyA와 같은 DicA의 상동성 단백질과는 달리 DicA는 N 말단에 있는 DNA 결합 도메인을 이용하여 20개의 염기쌍으로 이루어진 dicC 조절자 유전자(Oc)에 결합함을 보여주었다. 또한 in vivo 실험에서 DicA는 $37^{\circ}C$ 보다 $25^{\circ}C$에서 DNA에 더 잘 결합하는 것으로 알려진 Cnu 또는 H-NS의 영향을 받지 않고 자체적으로 Oc에서의 온도 의존적 DNA 결합을 보인다. 하지만 정제된 DicA 단백질을 이용한 in vitro binding 실험에서는 온도 의존적 DNA 결합이 관찰되지 않았다. Crude 단백질을 이용한 실험에서 DicA 단백질의 온도 의존적 DNA 결합이 관찰되는 것으로 보아 DicA의 온도 의존적 DNA (Oc) 결합은 crude 단백질내에 존재하는 아직 알려지지 않은 in vivo factor에 의해 일어난다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.1023-1026
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• 2007

Optimal damping layout of the constrained viscoelastic damping layer on beam is identified with temperatures by using a gradient-based numerical search algorithm. An optimal design problem is defined in order to determine the constrained damping layer configuration. A finite element formulation is introduced to model the constrained damping layer beam. The four-parameter fractional derivative model and the Arrhenius shift factor are used to describe dynamic characteristics of viscoelastic material with respect to frequency and temperature. Frequency-dependent complex-valued eigenvalue problems are solved by using a simple resubstitution algorithm in order to obtain the loss factor of each mode and responses of the structure. The results of the numerical example show that the proposed method can reduce frequency responses of beam at peaks only by reconfiguring the layout of constrained damping layer within a limited weight constraint.

• Structural Engineering and Mechanics
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• 제68권3호
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• pp.313-323
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• 2018

A numerical study is performed to investigate the impacts of thermal loading on the vibration and buckling of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) conical shells. Thermo-mechanical properties of constituents are considered to be temperature-dependent. Considering the shear deformation theory, the energy functional is derived, and applying the variational differential quadrature (VDQ) method, the mass and stiffness matrices are obtained. The shear correction factors are accurately calculated by matching the shear strain energy obtained from an exact three-dimensional distribution of the transverse shear stresses and shear strain energy related to the first-order shear deformation theory. Numerical results reveal that considering temperature-dependent material properties plays an important role in predicting the thermally induced vibration of FG-CNTRC conical shells, and neglecting this effect leads to considerable overestimation of the stiffness of the structure.