Activation parameters for transport and thermal expansion

1981 ◽  
Vol 59 (14) ◽  
pp. 2170-2172 ◽  
Author(s):  
Robert A. Stairs
Keyword(s):  
Activation Energy ◽  
Thermal Expansion ◽  
Internal Pressure ◽  
Viscous Flow ◽  
Diffusion Coefficients ◽  
High Pressures ◽  
Constant Pressure ◽  
Activation Parameters ◽  
Pressure Measurements ◽  
And Diffusion

A correlation is proposed between the ratios: Y = πΔV≠/E(p)≠ (where π is the internal pressure of a liquid, ΔV≠ the volume of activation RT(∂ ln η/∂p)T, and E(p)≠ the activation energy at constant pressure for viscous flow, or the corresponding quantities for diffusion) and X = E(ρ)≠/E(p) (where E(ρ) is the "energy of thermal expansion", defined by: −R[∂ ln (ρ−1 − ρ0−1)/∂T−1]p). The first, Y, involves quantities measured at high pressures, while X requires only measurements at ordinary pressure. The correlation will permit estimation of viscosities and diffusion coefficients at high pressures from low-pressure measurements.

scholarly journals Thermal Expansion and Diffusion Coefficients of Carbon Nanotube-Polymer Composites

Nano Letters ◽  
2002 ◽  
Vol 2 (6) ◽  
pp. 647-650 ◽  
Author(s):  
Chenyu Wei ◽  
Deepak Srivastava ◽  
Kyeongjae Cho
Keyword(s):  
Thermal Expansion ◽  
Carbon Nanotube ◽  
Polymer Composites ◽  
Diffusion Coefficients ◽  
And Diffusion

Effect of Li2O on Viscosity and Thermal Expansion of Silicate Glass

2011 ◽  
Vol 403-408 ◽  
pp. 70-74
Author(s):  
Kun Yang ◽  
Wei Hong Zheng ◽  
Jin Shu Cheng
Keyword(s):  
Activation Energy ◽  
Thermal Expansion ◽  
Viscous Flow ◽  
Melting Temperature ◽  
Silicate Glass ◽  
Coefficient Of Thermal Expansion ◽  
Viscosity Coefficient ◽  
Soda Lime ◽  
Softening Temperature ◽  
Soda Lime Silicate Glass

Subscript textViscosity, coefficient of thermal expansion, glass transition temperature and dilatometric softening temperature of soda-lime-silicate glass doped with Li2O were investigated by the rotating crucible viscometer and dilatometry, the melting temperature and activation energy for viscous flow of the studied melt were derived on the basis of Arrhenius Equation, in order to reveal the effects of Li2O on the properties of soda-lime-silicate glass. The results showed that the viscosity of soda-lime-silicate glass was effectively decreased and the melting temperature decreased from 1457°C to 1420°C with the increase of Li2O from 0 to 1.0wt%, furthermore, the Tgand Tsreduced 30~40°C. The ΔT responded to the range of viscosity of glass formation (η=103-107Pa•s) increased from 309.84°C to 313.45°C, and the activation energy for viscous flow decreased form 178.47 kJ•mol-1to 168.34 kJ•mol-1. The CTE α(25～400°C)of specimen doped with 0.4% Li2O was 92.048×10-6°C-1and the lowest of the samples.

A Physico-Chemical Study of Concentrated Aqueous Solutions of Lithium Chloride

1991 ◽  
Vol 46 (1-2) ◽  
pp. 141-147 ◽  
Author(s):  
Kazuko Tanaka ◽  
Reita Tamamushi
Keyword(s):  
Aqueous Solutions ◽  
Viscous Flow ◽  
Electric Conductivity ◽  
Lithium Chloride ◽  
Diffusion Coefficients ◽  
Chemical Study ◽  
Thermal Expansivity ◽  
Physico Chemical ◽  
Experimental Values ◽  
And Diffusion

AbstractThe experimental values of density, viscosity, electric conductivity and diffusion coefficients of trace ions in aqueous solutions of lithium chloride in wide ranges of concentration and temperature are collected and discussed. The thermal expansivity and the activation energies of viscous flow, electric conductance and diffusion of trace ions show significant changes at a molality around 12 mol/kg, beyond which the hydration requirement is not satisfied

scholarly journals Dynamic viscosity dependence on temperature for fuels used for diesel engine

2021 ◽  
Vol 32 (1) ◽  
pp. 98-103
Author(s):  
Irina Niţă ◽  
Sibel Osman ◽  
Olga Iulian
Keyword(s):  
Activation Energy ◽  
Diesel Engine ◽  
Viscous Flow ◽  
Dynamic Viscosity ◽  
Activation Parameters ◽  
Type Equation ◽  
Liquid Fuels ◽  
Activation Entropy ◽  
Different Temperatures ◽  
Viscosity Dependence

Abstract Viscosity is an important property of fuels used for diesel engine affecting engine’s efficiency and harmful gases emission. Viscosity of liquid fuels depends especially on fuels composition and temperature. The dynamic viscosity of diesel fuel, biodiesel and blends of diesel with biodiesel, i-propanol and n-butanol was measured for temperature ranging from 293.15 K to 323.15 K and atmospheric pressure. It has been verified that well-known Arrhenius derived equations can be used to estimate with good accuracy, viscosity at different temperatures for diesel, biodiesel, diesel+biodiesel blends, but also for diesel blends with propanol and butanol. Values of activation parameters: activation energy, activation enthalpy and activation entropy for the viscous flow were derived based on linearized Eyring’s type equation. The values of the activation energy for viscous flow of fuels and fuels blends calculated based on measured values of dynamic viscosity in the temperature range of 273.15 K and 323.15 K were similar to those presented in the literature for some hydrocarbons, esters, and alcohols, respectively.

scholarly journals Molecular dynamic simulation study of molten cesium

2017 ◽  
Vol 82 (6) ◽  
pp. 681-694 ◽  
Author(s):  
Saeid Yeganegi ◽  
Vahid Moeini ◽  
Zohreh Doroodi
Keyword(s):  
Internal Pressure ◽  
Diffusion Coefficients ◽  
Distribution Functions ◽  
Radial Distribution Functions ◽  
Coordination Numbers ◽  
Self Diffusion ◽  
Temperature And Pressure ◽  
Molecular Dynamic Simulation Study ◽  
Dynamics Simulations ◽  
And Diffusion

Molecular dynamics simulations were performed to study thermodynamics and structural properties of expanded caesium fluid. Internal pressure, radial distribution functions (RDFs), coordination numbers and diffusion coefficients have been calculated at temperature range 700?1600 K and pressure range 100?800 bar. We used the internal pressure to predict the metal?non-metal transition occurrence region. RDFs were calculated at wide ranges of temperature and pressure. The coordination numbers decrease and positions of the first peak of RDFs slightly increase as the temperature increases and pressure decreases. The calculated self-diffusion coefficients at various temperatures and pressures show no distinct boundary between Cs metallic fluid and its expanded fluid where it continuously increases with temperature.

Relationship between Viscous Flow and Diffusion

Nature ◽  
1962 ◽  
Vol 195 (4840) ◽  
pp. 482-483 ◽  
Author(s):  
F. A. L. DULLIEN
Keyword(s):  
Viscous Flow ◽  
And Diffusion

The Inductive Coil Technique for High-Pressure Measurements: An Analysis of Nonhomogeneous Material Environment as a Source of Irreproducibility and Error

1967 ◽  
Vol 89 (3) ◽  
pp. 554-560 ◽  
Author(s):  
A. A. Giardini
Keyword(s):  
High Pressure ◽  
Internal Pressure ◽  
Elastic Constants ◽  
Graphical Form ◽  
Pressure Measurements ◽  
Pressure Data ◽  
Nonhomogeneous Material ◽  
Resistivity Measurements ◽  
Material Environment ◽  
Critical Yield

Significant sources of error independent of the apparatus are analyzed on the basis of experimental experience and elastic theory. All are mechanical in nature and subject to corrective action. The most serious is found to be self-generating internal pressure differences which result from differential elastic and dimensional values in multicomponent assemblies. High-pressure data on elastic constants, relative critical yield stresses, radial displacements, and ratios of external to internal pressure for various compositional arrangements of pyrophyllite, MgO, NaCl, and AgCl are given in graphical form. Observance of suggested corrective measures can render the inductive coil technique capable of operational accuracies of 2 percent or better in compressibility and resistivity measurements.

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