TEMPERATURE-DEPENDENCE OF PROTON CONDUCTIVITY IN HYDROGEN-BONDED MOLECULAR SYSTEMS

2007 ◽  
Vol 21 (19) ◽  
pp. 1239-1252 ◽  
Author(s):  
XIAO-FENG PANG ◽  
BO DENG ◽  
HUAI-WU ZHANG ◽  
YUAN-PING FENG
Keyword(s):  
Experimental Data ◽  
Electric Field ◽  
Temperature Dependence ◽  
Electric Conductivity ◽  
Proton Conductivity ◽  
Model System ◽  
Time Dependent ◽  
Molecular Systems ◽  
Damping Effect ◽  
Hydrogen Bonded

The temperature-dependence of proton electric conductivity in hydrogen-bonded molecular systems with damping effect was studied. The time-dependent velocity of proton and its mobility are determined from the Hamiltonian of a model system. The calculated mobility of (3.57–3.76) × 10-6 m 2/ Vs for uniform ice is in agreement with the experimental value of (1 - 10) × 10-2 m 2/ Vs . When the temperature and damping effects of the medium are considered, the mobility is found to depend on the temperature for various electric field values in the system, i.e. the mobility increases initially and reaches a maximum at about 191 K, but decreases subsequently to a minimum at approximately 241 K, and increases again in the range of 150–270 K. This behavior agrees with experimental data of ice.

THE PROPERTIES OF PROTON CONDUCTIVITY ALONG THE HYDROGEN-BONDED MOLECULAR SYSTEMS WITH DAMPING UNDER INFLUENCES OF THERMAL PERTURBATION AND STRUCTURE NONUNIFORMITY

2011 ◽  
Vol 25 (01) ◽  
pp. 55-71 ◽  
Author(s):  
XIAO-FENG PANG ◽  
JIA-FENG YU ◽  
HONG-JUAN ZENG
Keyword(s):  
Electric Field ◽  
Force Constant ◽  
Proton Conductivity ◽  
Temperature Region ◽  
Applied Electric Field ◽  
Damping Coefficient ◽  
Thermal Perturbation ◽  
Molecular Systems ◽  
Hydrogen Bonded Systems ◽  
Hydrogen Bonded

The effects of structure nonuniformity and thermal perturbation on properties of proton conductivity in hydrogen-bonded systems with damping exposed in an externally applied electric-field have been numerically studied by fourth order Runge–Kutta method in our soliton model. The results obtained show that the proton-soliton is very robust against the structure disorder including the fluctuation of the force constant and disorder in the sequence of masses and thermal perturbation and damping effect of medium, its velocity of conductivity increases with increasing externally applied electric-field and with decreasing damping coefficient of medium, but the proton-soliton disperses at quite great fluctuations of force constant and damping coefficient. In the meantime, the proton-soliton in ice crystals is thermally stable in the region of temperature of T ≤ 273 K. From the numerical simulation, we find out that the mobility (or velocity) of proton conduction in ice is a nonmonotonic function of temperature in the temperature region of 170–273 K, i.e., it increases initially, reaches a maximum at about 191.4 K, subsequently decreases to a minimum at about 211.6 K, and then increases again. This changed rule of mobility obtained consists qualitatively with its experimental datum in ice in the same temperature region. Thus these results provide an evidence for the soliton excited in the hydrogen-bonded systems.

PROTON CONDUCTIVITY AND THERMODYNAMIC FEATURES IN THE HYDROGEN-BONDED MOLECULAR SYSTEMS

2005 ◽  
Vol 19 (25) ◽  
pp. 3835-3859 ◽  
Author(s):  
XIAO-FENG PANG ◽  
HUAI-WU ZHANG ◽  
JUN ZN
Keyword(s):  
Electrical Conductivity ◽  
Proton Transfer ◽  
Specific Heat ◽  
Proton Conductivity ◽  
Soliton Solutions ◽  
Mutual Correlation ◽  
Molecular Systems ◽  
Model Hamiltonian ◽  
Transfer Integral ◽  
Hydrogen Bonded

The proton conductivity and thermodynamic features, arising from motions of the ionic and bonded defects, in hydrogen-bonded molecular systems have been investigated by the quantum-mechanical method and the transfer integral way in our model, in which the collective effect and the mutual correlation between the protonic and heavy ionic sublattices are specially considered. We first derived the equations of motion and its soliton solutions from the model Hamiltonian. The results obtained show that this model can simultaneously support motions of the ionic and bonded defects which are due to competition of the double-well potential and non-linearly coupled interaction between the protons and heavy ions. Thus we find out the mobility of the kink-antikink pair and electrical-conductivity of the proton transfer in the hydrogen-bonded systems exposed in an externally applied electrical-field through the dynamic equation of the kink-antikink pair and its solution in this model. For ice, the mobility and electrical conductivity of the proton transfer obtained are about (6.5 - 6.9)×10-6 m 2/ V · s and (7.6 - 8.1)×10-3(Ω · m )-1, respectively, which are in the domain of semiconductors and are basically consistent with experimental values for the crystal. Finally we calculate the free energy and specific heat of the systems with finite temperature by the model Hamiltonian and transfer integral way. The specific heat is also consistent with experimental data. This is a very interesting result.

Temperature-dependence of time-dependent friction and electric field fluctuations

1994 ◽  
Vol 106 (2) ◽  
pp. 467-477
Author(s):  
K. R. Sivaprasad ◽  
V. Prasad ◽  
K. Manjula Devi ◽  
B. L. Tembe
Keyword(s):  
Electric Field ◽  
Temperature Dependence ◽  
Time Dependent ◽  
Field Fluctuations

Comparison of Rate-Dependent Ferroelectroelastic Phenomenological Models for Prediction of PZT Creep

2015 ◽  
Vol 725-726 ◽  
pp. 961-966
Author(s):  
Artem S. Semenov ◽  
Sviatoslav Lobanov
Keyword(s):  
Experimental Data ◽  
Electric Field ◽  
Phenomenological Models ◽  
Phenomenological Model ◽  
Constant Electric Field ◽  
Time Dependent ◽  
Piezoceramic Material ◽  
Rate Dependent

The time-dependent effects of piezoceramic material under the constant electric field are analyzed. The new rate-dependent ferroelectroelastic phenomenological model is proposed and compared with known models and experimental data.

TEMPERATURE DEPENDENCE BEHAVIOR OF ELECTRICAL RESISTIVITY IN NOBLE METALS AT LOW TEMPERATURES

2014 ◽  
Vol 5 (3) ◽  
pp. 982-992 ◽  
Author(s):  
M AL-Jalali
Keyword(s):  
Experimental Data ◽  
Electrical Resistivity ◽  
Temperature Dependence ◽  
Concentration Dependence ◽  
Low Temperatures ◽  
Noble Metals ◽  
Phonon Scattering ◽  
Theoretical Models ◽  
Residual Resistivity ◽  
Electron Phonon Scattering

Resistivity temperature – dependence and residual resistivity concentration-dependence in pure noble metals(Cu, Ag, Au) have been studied at low temperatures. Dominations of electron – dislocation and impurity, electron-electron, and electron-phonon scattering were analyzed, contribution of these mechanisms to resistivity were discussed, taking into consideration existing theoretical models and available experimental data, where some new results and ideas were investigated.

scholarly journals Ability of Constitutive Models to Characterize the Temperature Dependence of Rubber Hyperelasticity and to Predict the Stress-Strain Behavior of Filled Rubber under Different Defor Mation States

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 369
Author(s):  
Xintao Fu ◽  
Zepeng Wang ◽  
Lianxiang Ma
Keyword(s):  
Experimental Data ◽  
Temperature Dependence ◽  
Mechanical Response ◽  
Constitutive Models ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Chain Model ◽  
Stress Strain ◽  
Filled Rubber ◽  
Yeoh Model

In this paper, some representative hyperelastic constitutive models of rubber materials were reviewed from the perspectives of molecular chain network statistical mechanics and continuum mechanics. Based on the advantages of existing models, an improved constitutive model was developed, and the stress–strain relationship was derived. Uniaxial tensile tests were performed on two types of filled tire compounds at different temperatures. The physical phenomena related to rubber deformation were analyzed, and the temperature dependence of the mechanical behavior of filled rubber in a larger deformation range (150% strain) was revealed from multiple angles. Based on the experimental data, the ability of several models to describe the stress–strain mechanical response of carbon black filled compound was studied, and the application limitations of some constitutive models were revealed. Combined with the experimental data, the ability of Yeoh model, Ogden model (n = 3), and improved eight-chain model to characterize the temperature dependence was studied, and the laws of temperature dependence of their parameters were revealed. By fitting the uniaxial tensile test data and comparing it with the Yeoh model, the improved eight-chain model was proved to have a better ability to predict the hyperelastic behavior of rubber materials under different deformation states. Finally, the improved eight-chain model was successfully applied to finite element analysis (FEA) and compared with the experimental data. It was found that the improved eight-chain model can accurately describe the stress–strain characteristics of filled rubber.

Modal Analysis of the Axial Compressor Blade: Advanced Time-Dependent Electronic Interferometry and Finite Element Method

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mykhaylo Tkach ◽  
Serhii Morhun ◽  
Yuri Zolotoy ◽  
Irina Zhuk
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Finite Element ◽  
High Reliability ◽  
Axial Compressor ◽  
Time Dependent ◽  
Experimental Setup ◽  
Vibration Modes ◽  
Compressor Blades ◽  
Isoparametric Finite Element

AbstractNatural frequencies and vibration modes of axial compressor blades are investigated. A refined mathematical model based on the usage of an eight-nodal curvilinear isoparametric finite element was applied. The verification of the model is carried out by finding the frequencies and vibration modes of a smooth cylindrical shell and comparing them with experimental data. A high-precision experimental setup based on an advanced method of time-dependent electronic interferometry was developed for this aim. Thus, the objective of the study is to verify the adequacy of the refined mathematical model by means of the advanced time-dependent electronic interferometry experimental method. The divergence of the results of frequency measurements between numerical calculations and experimental data does not exceed 5 % that indicates the adequacy and high reliability of the developed mathematical model. The developed mathematical model and experimental setup can be used later in the study of blades with more complex geometric and strength characteristics or in cases when the real boundary conditions or mechanical characteristics of material are uncertain.

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