• 대한수학회지
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• 제58권5호
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• pp.1131-1145
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• 2021

In this article, we study the Klein-Gordon-Maxwell equations arising from a semilocal gauge field model. This model describes the interaction of two complex scalar fields and one gauge field, and generalizes the classical Klein-Gordon equation coupled with the Maxwell electrodynamics. We prove that there exist infinitely many standing wave solutions for p ∈ (2, 6) which are radially symmetric. Here, p comes from the exponent of the potential of scalar fields. We also prove the nonexistence of nontrivial solutions for the critical case p = 6.

• 대한수학회보
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• 제48권5호
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• pp.1111-1117
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• 2011

Using the moving plane method, we establish the radial symmetry of topological one-vortex solutions of a semilinear elliptic system arising from the self-dual Maxwell-Chern-Simons O(3) model.

• 대한수학회논문집
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• 제19권2호
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• pp.283-291
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• 2004

In this paper we show the radial symmetry of topological one-vortex solutions in the Maxwell-Chern-Simons-Higgs Model.

• Korean Chemical Engineering Research
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• 제56권5호
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• pp.767-772
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• 2018

전기유변(ER) 현상을 위해 제시된 메커니즘들이 중에서 정전기 분극 모델과 전도 모델이 이론적인 측면에서 적합한 것으로 알려져 있다. 그러나 이 모델들은 자체적인 제한들 때문에 효과적인 ER 액체의 개발에 적절한 도움이 되지 못했다. 이 문제를 해결하기 위해 Onsager 이론으로 확장한 Maxwell-Wagner 분극 모델을 개발하였다. 확장한 Maxwell-Wagner 분극 모델은 항복응력의 전기장 주파수 및 전기장 크기의 비제곱 의존성을 설명할 수 없는 정전기 분극 모델의 단점과 전기장 하에서의 입자의 미세 구조 변화를 예측할 수 없는 전도 모델의 단점을 해결할 수 있었다. 또한 이 모델은 정전기 분극 모델과 전도 모델에서 예측할 수 없었던 항복응력에의 입자 전도도 영향을 고려할 수 있는 장점도 있어 효과적인 ER 액체의 개발에 기여하리라 판단된다.

• Korean Chemical Engineering Research
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• 제58권3호
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• pp.480-485
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• 2020

Onsager 이론으로 확장된 Maxwell-Wagner 분극 모델을 이용하여 전도성 입자로 제조된 전기유변(Electrorheological, ER) 액체의 전기유변 현상에 대한 전산 모사를 수행하였다. 확장된 Maxwell-Wagner 분극 모델을 이용한 전산 모사는 전도성 입자로 제조된 전기유변 액체의 특성인 비제곱 전기유변 현상(Δτ∝Eⁿ, n≈1.5)을 확인하였다. 전단 흐름에서 전단응력이 정상상태에 도달하는 시점은 전기장 하에서 생성된 사슬 모양 구조가 전단 흐름에 의해 깨짐과 재생성이 정상상태에 도달하는 지점으로 나타났다. 또한, 전단 속도의 증가에 따라 전단응력이 최솟값을 보이는 전도성 입자를 기반으로 한 전기유변 액체의 현상도 관찰하였으며, 이것은 입자의 사슬 모양 구조가 무작위 배열로 바뀌는 순간에 발생하는 것임을 관찰하였다. 입자의 부피 분율 ϕ가 증가에 따라 전단응력은 증가하다가 일정해지는 경향도 관찰하였다.

• Geomechanics and Engineering
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• 제14권3호
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• pp.225-231
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• 2018

In this paper, in order to explain the splitting of cylindrical rock specimen under uniaxial loading, cracks in cylindrical rock specimen are divided into two kinds, the longitudinal crack and the slanting crack. Mechanical behavior of the rock is described by elastic-brittle-plastic model and splitting is assumed to suddenly occur when the uniaxial compressive strength is reached. Expression of the stresses induced by the longitudinal crack in direction perpendicular to the major axis of the crack is deduced by using the Maxwell model. Results show that the induced stress is tensile and can be greater than the tensile strength even before the uniaxial compressive strength is reached. By using the Inglis's formula and simplifying the cracks as slender ellipse, the above conclusions that drawn by using the Maxwell model are confirmed. Compared to shearing fracture, energy consumption of splitting seems to be less, and splitting is most likely to occur when the uniaxial loading is great and quick. Besides, explaining the rock core disking occurred under the fast axial unloading by using the Maxwell model may be helpful for understanding that rock core disking is fundamentally a tensile failure phenomenon.

• Transactions on Electrical and Electronic Materials
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• 제8권3호
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• pp.139-142
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• 2007

Organic field-effect transistor (FET) based on a copper Phthalocyanine (CuPc) material as an active layer and a $SiO_2$ as a gate insulator were fabricated and analyzed. We measured the typical FET characteristics of CuPc in air. The electrical characteristics of the CuPc FET device were analyzed by a Maxwell-Wagner model. The Maxwell-Wagner model employed in analyzing double-layer dielectric system was helpful to explain the C-V and I-V characteristics of the FET device. In order to further clarity the channel formation of the CuPc FET, optical second harmonic generation (SHG) measurement was also employed. Interestingly, SHG modulation was not observed for the CuPc FET. This result indicates that the accumulation of charge from bulk CuPc makes a significant contribution.

• 유변학
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• 제3권1호
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• pp.47-55
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• 1991

본 연구에서는 구형기포가 미분형의 upper convected Maxwell 모델을 따르는 유체 내에서 수축할 때의 현상을 이론적으로 해석하였다. 수치해법으로는 Lagrangian 좌표계에서 지배방정식을 유도 사용함으로써 자연스럽게 자유표면을 추적하는 동시에 압력변수도 반복 에 의하지 않고 직접적인 방법으로 계산할 수 있는 Galerkin-유한요소법을 개발사용하였다. 본연구의 결과 유체의 탄성은 변형초기에 충분히 발달치 못하기 때문에 수축을 가속화시키 지만 수축 후기에는 지연시킴을 알 수 있었다. 수축의 속도는 적분형 Maxwell 유체에서 보 다 빠른 것을 알수 있었는데 이는 유체의 정지이력에 의한 것으로 판단되었다, 또한 Maxwell 유체내에서 기포가 수축할 경우 탄성에 의한 반동현상이 나타나며 반동이 점성에 의하여 감쇄될 때의 진폭과 주기는 비례함을 보였다.

• Bulletin of the Korean Chemical Society
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• 제13권4호
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• pp.413-419
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• 1992

The theoretical equation for the relaxation spectrum of nonlinear viscoelastic polymeric material was derived from the Ree-Eyring and Maxwell non-Newtonian model. This model consists of infinite number of hyperbolic sine law Maxwell elements coupled in parallel plus a spring without a dashpot. Infinite number of nonlinear viscoelastic Maxwell elements can be used by specifying distribution of relaxation times, hole volumes, molecular weights, crystallite size and conformational size, etc. The experimentals of stress relaxation were carried out using the tensile tester with the solvent chamber. The relaxation spectra of nylon 6 filament fibers in various electrolytic solutions were obtained by applying the experimental stress relaxation curves to the theoretical equation of relaxation spectrum. The determination of relaxation spectra was performed from computer calculation.

• Geomechanics and Engineering
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• 제9권4호
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• pp.499-511
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• 2015

The creep property of salt rock significantly influences the long-term stability of the salt rock underground storage. Triaxial creep tests were performed to investigate the creep behavior of salt rock. The test results indicate that the creep of salt rock has a nonlinear characteristic, which is related to stress level and creep time. The higher the stress level, the longer the creep time, the more obvious the nonlinear characteristic will be. The elastic modulus of salt rock decreases with the prolonged creep time, which shows that the creep damage is produced for the gradual expansion of internal cracks, defects, etc., causing degradation of mechanical properties; meanwhile, the creep rate of salt rock also decreases with the prolonged creep time in the primary creep stage, which indicates that the mechanical properties of salt rock are hardened and strengthened. That is to say, damage and hardening exist simultaneously during the creep of salt rock. Both the damage effect and the hardening effect are considered, an improved Maxwell creep model is proposed by connecting an elastic body softened over time with a viscosity body hardened over time in series, and the creep equation of which is deduced. Creep test data of salt rock are used to evaluate the reasonability and applicability of the improved Maxwell model. The fitting curves are in excellent agreement with the creep test data, and compared with the classical Burgers model, the improved Maxwell model is able to precisely predict the long-term creep deformation of salt rock, illustrating our model can perfectly describe the creep property of salt rock.