• Title/Summary/Keyword: Maxwell Model

Search Result 259, Processing Time 0.023 seconds

ON SEMILOCAL KLEIN-GORDON-MAXWELL EQUATIONS

  • Han, Jongmin;Sohn, Juhee;Yoo, Yeong Seok
    • Journal of the Korean Mathematical Society
    • /
    • v.58 no.5
    • /
    • pp.1131-1145
    • /
    • 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.

Extended Maxwell-Wagner Polarization Model with Onsager Theory for the Electrorheological Phenomena (전기유변현상 해석을 위하여 Onsager 이론으로 확장한 Maxwell-Wagner 분극 모델)

  • Kim, Young Dae
    • Korean Chemical Engineering Research
    • /
    • v.56 no.5
    • /
    • pp.767-772
    • /
    • 2018
  • Among various mechanisms for ER phenomena, the electrostatic polarization and conduction models were known as the most promising theoretical models. However, many inherited defects have limited their uses for the development of effective ER fluids. To resolve these problems, extended Maxwell-Wagner polarization model with Onsager theory was developed. It was observed that the extended model resolved the problems, suggesting that the extended model can be used for the development of effect ER fluids.

Simulation of Electrorheological Fluids by the Extended Maxwell-Wagner Polarization Model with Onsager Theory (Onsager 이론으로 확장한 Maxwell-Wagner 분극 모델에 의한 전기유변 현상 모사)

  • Kim, Young Dae
    • Korean Chemical Engineering Research
    • /
    • v.58 no.3
    • /
    • pp.480-485
    • /
    • 2020
  • The extended Maxwell-Wagner polarization model is employed to describe the ER behavior of the conducting particle ER suspensions, and solutions to the equation of motion are obtained by dynamic simulation. The simulation results show the nonlinear ER behavior (Δτ∝En, n≈1.5) of the conducting particle ER suspensions. The response point, where shear stress reaches steady-state, is the point where stable break-up and rebuild of the chain-like structure of particles reaches. Also, it shows the minimum of shear stress, which corresponds the start-up of random particle configuration. The shear stress reaches plateau as particle volume fraction increases.

Theoretical explanation of rock splitting based on the micromechanical method

  • Huang, Houxu;Li, Jie;Hao, Yiqing;Dong, Xin
    • Geomechanics and Engineering
    • /
    • v.14 no.3
    • /
    • pp.225-231
    • /
    • 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.

Copper Phthalocyanine Field-effect Transistor Analysis using an Maxwell-wagner Model

  • Lee, Ho-Shik;Yang, Seung-Ho;Park, Yong-Pil;Lim, Eun-Ju;Iwamoto, Mitsumasa
    • Transactions on Electrical and Electronic Materials
    • /
    • v.8 no.3
    • /
    • pp.139-142
    • /
    • 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.

A Study on the Collapse of Spherical bubbles in Maxwell Fluids of Differential Model (미분형 Maxwell 유체내 구형기포의 수축에 관한연구)

  • 김종엽
    • The Korean Journal of Rheology
    • /
    • v.3 no.1
    • /
    • pp.47-55
    • /
    • 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.

  • PDF

The Rheological and Mechanical Model for Relaxation Spectra of Polydisperse Polymers

  • Kim, Nam Jeong;Kim, Eung Ryul;Hahn Sang Joon
    • Bulletin of the Korean Chemical Society
    • /
    • v.13 no.4
    • /
    • pp.413-419
    • /
    • 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.

An improved Maxwell creep model for salt rock

  • Wang, Jun-Bao;Liu, Xin-Rong;Song, Zhan-Ping;Shao, Zhu-Shan
    • Geomechanics and Engineering
    • /
    • v.9 no.4
    • /
    • pp.499-511
    • /
    • 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.