scholarly journals Surface tension of liquid Ti with adsorbed oxygen and a simple associate model for its prediction

2020 ◽  
Vol 49 (1-2) ◽  
pp. 89-105 ◽  
Author(s):  
J. BRILLO ◽  
J. WESSING ◽  
H. KOBATAKE ◽  
H. FUKUYAMA
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Simple Model ◽  
Chemical Analysis ◽  
Mole Fraction ◽  
Tio2 Powder ◽  
Bulk Oxygen ◽  
Electromagnetically Levitated ◽  
Oxygen Mole Fraction ◽  
Good Agreement

Surface tensions of electromagnetically levitated liquid Ti-samples were measured under the influence of oxygen. For this purpose, Ti-O samples were prepared by adding different amounts of TiO2 powder to pure Ti. The surface tension was found to strongly depend on the bulk oxygen mole fraction determined by chemical analysis. The results could be described by a simple model presented in the present work. In this model the Butler equation is applied and the formation of TiO2 – associates are taken into account. Non-ideal interactions ΔH≠0 between titanium and the associates also need to be taken into account. Good agreement with the experimental data is evident and also with a different model developed earlier by us.

scholarly journals Estimate of Glacier Ablation under a Debris Layer from Surface Temperature and Meteorological Variables

1982 ◽  
Vol 28 (98) ◽  
pp. 29-34 ◽  
Author(s):  
M. Nakawo ◽  
G.J. Young
Keyword(s):  
Experimental Data ◽  
Simple Model ◽  
Surface Temperature ◽  
Temperature Data ◽  
Meteorological Variables ◽  
Glacier Ablation ◽  
Surface Temperature Data ◽  
Good Agreement

AbstractA simple model suggests that the ablation under a debris layer could be estimated from meteorological variables if the surface temperature data of the layer are available. This method was tested by analyzing the data obtained from experiments with artificial debris layers. Fairly good agreement was obtained between the estimated and the experimental data.

scholarly journals Surface tension of O2-Ar, N2-Ar and O2-N2-Ar mixtures

2019 ◽  
pp. 21-27
Author(s):  
Mauricio García-Martínez ◽  
Benjamín Ibarra-Tandi ◽  
Daniel Porfirio Luis-Jiménez ◽  
Jorge López-Lemus
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Force Fields ◽  
Ternary Mixtures ◽  
Binary And Ternary Mixtures ◽  
Experimental Surface ◽  
Argon Mixture ◽  
Dynamics Simulations ◽  
Tension Curves ◽  
Good Agreement

The surface tension of some binary and ternary mixtures was calculated by means of molecular dynamics simulations in a canonical set. The analyzed mixtures were oxygen-argon, nitrogen-argon and oxygen-nitrogen-argon. The force field for argon was recalculated in order to reproduce the experimental surface tension. The corresponding force fields for O2 and N2 were taken from a previous work [Mol. Simul. 45 (2019) 958-966], where it was shown that such force fields reproduce the experimental surface tension curves, as pure fluids. The nitrogen-argon surface tension was calculated for several mole fractions of argon. The obtained curve was compared with those experimental data and a good agreement was found. The standard Lorentz-Berthelot combining rules were employed. For the oxygen-argon mixture it was necessary to modify the cross term of the combining rules in order to reproduce theoretical and experimental data. The surface tension of the ternary mixture was also estimated varying the mole fraction of argon at a certain concentration of oxygen and nitrogen, previously adjusted. Several temperatures were used in order to show a tendency mostly at relatively low temperatures. After comparing the available experimental data, which are scarce, a good agreement was observed.

scholarly journals Estimate of Glacier Ablation under a Debris Layer from Surface Temperature and Meteorological Variables

1982 ◽  
Vol 28 (98) ◽  
pp. 29-34 ◽  
Author(s):  
M. Nakawo ◽  
G.J. Young
Keyword(s):  
Experimental Data ◽  
Simple Model ◽  
Surface Temperature ◽  
Temperature Data ◽  
Meteorological Variables ◽  
Glacier Ablation ◽  
Surface Temperature Data ◽  
Good Agreement

AbstractA simple model suggests that the ablation under a debris layer could be estimated from meteorological variables if the surface temperature data of the layer are available. This method was tested by analyzing the data obtained from experiments with artificial debris layers. Fairly good agreement was obtained between the estimated and the experimental data.

scholarly journals Estimating the Maximum Splat Diameter of a Solidifying Droplet

1999 ◽  
Author(s):  
Nicolas G. Hadjiconstantinou
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Contact Angle ◽  
Simple Model ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Simple Analytical Model ◽  
Droplet Spreading ◽  
Isothermal Model ◽  
High Reynolds

Abstract We present a simple analytical model for the estimation of the maximum splat diameter of an impacting droplet on a subcooled target. This work is an extension of the isothermal model of Pasandideh-Fard et al. (1996). The model uses an energy conservation argument, applied between the initial and final drop configurations, to approximately capture the dynamics of spreading. The effects of viscous dissipation, surface tension, and contact angle are taken into account. Tests against limited experimental data at high Reynolds and Weber numbers indicate that an accuracy of the order of 5% is achieved with no adjustable parameters required. Agreement with experimental data in the limit We → ∞ is also very good. We additionally propose a simple model for the estimation of the thickness of the freezing layer developed at the droplet-substrate contact during droplet spreading. This model accounts for the effect of thermal contact resistance and its predictions compare favorably with experimental data.

A Model of CoO Oxidation

1993 ◽  
Vol 58 (12) ◽  
pp. 2853-2866
Author(s):  
Marcela Tkadlecová
Keyword(s):  
Experimental Data ◽  
Temperature Dependence ◽  
Mole Fraction ◽  
Rate Constant ◽  
Surface Reaction ◽  
Energy Of Activation ◽  
The Given ◽  
Oxygen Mole Fraction

A model of CoO oxidation was proposed which assumes the diffusion of cobalt atoms from the bulk of crystalline to its surface and the surface reaction of these atoms with surrounding oxygen. It depends on the comparison of expressions D/a20 and kxox/a0 to what extent these two processes will manifest themselves for the given temperature and oxygen mole fraction xox. The value of diffusivity D and its temperature dependence were estimated from the data in literature and the size of crystallites a0 from roentgenographic measurements. The value of rate constant of surface reaction k and its energy of activation were evaluated from experimental data for CoO oxidation.

Speed of Sound in Bubbly Liquids

1969 ◽  
Vol 184 (3) ◽  
pp. 102-107 ◽  
Author(s):  
D. McWilliam ◽  
R. K. Duggins
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Speed Of Sound ◽  
Bubble Size ◽  
Gas Bubbles ◽  
Gas Content ◽  
Sonic Velocity ◽  
Bubbly Liquids ◽  
Liquid Compressibility ◽  
Good Agreement

The variations of density and sonic velocity with gas content have been calculated for a liquid containing gas bubbles. Taking liquid compressibility and surface tension into account, the effects of pressure and bubble size have been assessed. Particular attention has been focused on air-water mixtures, and very good agreement has been obtained with the limited amount of experimental data available.

Modeling of the surface tension of liquid Fe-P alloy by calculation of liquidus line in Fe-P binary system

2006 ◽  
Vol 21 (6) ◽  
pp. 1399-1408 ◽  
Author(s):  
Han S. Kim ◽  
Y. Kobayashi ◽  
K. Nagai
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Binary System ◽  
Composition Range ◽  
Liquidus Line ◽  
Liquid Solution ◽  
Wide Composition Range ◽  
Binary Liquid ◽  
Temperature Ranges ◽  
Good Agreement

The surface tension of the Fe-P binary liquid solution was computed using a Butler's model in wide composition and temperature ranges by adopting the activity coefficient data that were evaluated from the phase diagram calculation. In the surface tension modeling, the Fe-P binary system was assumed as the Fe-Fe3P pseudo-binary system. The results of the computation were critically compared with the experimental data of the literature considering the effects of the size of the adsorbed elements and the interactions among them. The results of the computation at 1823 K showed good agreement with the selected experimental data of the literature in a wide composition range from 0 to 15 mass%P. Furthermore, the results of the computation at 0.5 mass%P showed good correlation with the selected experimental data of the literature in a wide temperature range from 1823 K to 1923 K.

A Hybrid Model to Predict the Onset of Gas Entrainment With Surface Tension Effects

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
W. Saleh ◽  
R. C. Bowden ◽  
I. G. Hassan ◽  
L. Kadem
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Three Dimensional ◽  
Radius Of Curvature ◽  
Liquid Region ◽  
Two Dimensional ◽  
Poor Agreement ◽  
Critical Height ◽  
Gas Entrainment ◽  
Good Agreement

The onset of gas entrainment in a single downward discharge, from a stratified gas-liquid region, was modeled. The discharge was modeled as a point-sink and Kelvin–Laplace’s equation was used to incorporate surface tension effects. Consequently, a criterion to characterize the dip radius of curvature, at the onset of gas entrainment, was required. The dip geometry was experimentally investigated and a correlation was developed relating the dip radius of curvature to the discharge Froude number. The correlation was used in conjunction with the theoretical model. It was found that the predicted critical height demonstrated good agreement with experimental data with the three-dimensional point-sink approach, while poor agreement using the two-dimensional finite-branch approach was found. The inclusion of surface tension improved the model’s capability to predict the critical height, particularly at discharge Froude numbers below 1.

Estimation of the Thermodynamic Properties of Unbranched Hydrocarbons

1999 ◽  
Vol 121 (1) ◽  
pp. 45-50 ◽  
Author(s):  
H. He ◽  
M. Metghalchi ◽  
J. C. Keck
Keyword(s):  
Experimental Data ◽  
Heat Capacity ◽  
Free Energy ◽  
Simple Model ◽  
Thermodynamic Properties ◽  
Statistical Thermodynamic ◽  
Wide Range ◽  
On Line ◽  
Kinetic Calculations ◽  
Good Agreement

A simple model has been developed to estimate the sensible thermodynamic properties such as Gibbs free energy, enthalpy, heat capacity, and entropy of unbranched hydrocarbons over a wide range of temperatures. The model is based on statistical thermodynamic expressions incorporating translational, rotational, and vibrational motions of the atoms. A relatively small number of parameters are needed to calculate the thermodynamic properties of a wide range of molecules. The calculated results are in good agreement with the available experimental data for unbranched hydrocarbons. The model can be used to make estimates for molecules whose properties have not been measured and is simple enough to be easily programmed as a subroutine for on-line kinetic calculations.

RECONSTRUCTION OF PRESSURE–COMPOSITION–TEMPERATURE CURVES OFRNi5(R = La, Pr, Nd, and Sm) HYDROGEN STORAGE MATERIALS BY COMPUTER SIMULATION

2009 ◽  
Vol 08 (04n05) ◽  
pp. 409-413
Author(s):  
VASILEIOS TSEROLAS ◽  
MASAHIKO KATAGIRI ◽  
HIDEHIRO ONODERA ◽  
HIROSHI OGAWA
Keyword(s):  
Experimental Data ◽  
Computer Simulation ◽  
Simple Model ◽  
Hydrogen Storage ◽  
Electrochemical Performance ◽  
Plateau Pressure ◽  
Hydrogen Storage Materials ◽  
Hydrogen Atoms ◽  
Storage Materials ◽  
Good Agreement

RNi5-type metal hydride materials have been simulated by using a simple model. These materials have been thoroughly studied with respect to their physical and electrochemical performance. Examples of simulated P–C–T curves are drawn. The simulations demonstrate good agreement with the experimental data reported for various RNi5-type hydrogen storage materials. As expected, the plateau pressure increases with increasing temperatures. It also becomes more difficult to insert hydrogen atoms at higher temperatures, which is generally accepted to occur. Finally, limitations of the model are discussed and possible solutions to overcome these limitations are proposed.

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