SURFACE ENERGIES OF THE ALKALI HALIDES

1955 ◽  
Vol 33 (2) ◽  
pp. 232-239 ◽  
Author(s):  
G. C. Benson ◽  
G. W. Benson
Keyword(s):  
Particle Size ◽  
Sodium Chloride ◽  
Theoretical Calculations ◽  
Alkali Halides ◽  
Experimental Measurements ◽  
Calorimetric Study ◽  
Heat Of Solution ◽  
Surface Energies ◽  
Effect Of Particle Size ◽  
Surface Enthalpy

Previous theoretical calculations and experimental measurements of the surface energies or enthalpies of the alkali halides are reviewed briefly. A new attempt to determine the surface enthalpy associated with the {100} face of sodium chloride from a calorimetric study of the effect of particle size on the heat of solution is described. The result (305 ergs/cm.2 at 25 °C.) appears to be larger than might be predicted on the basis of the classical Born-Mayer theory.

THE QUANTUM MECHANICAL CALCULATION OF THE SURFACE ENERGY OF SODIUM CHLORIDE— A FIRST APPROXIMATION

1956 ◽  
Vol 34 (9) ◽  
pp. 985-992 ◽  
Author(s):  
G. C. Benson ◽  
F. Van Zeggeren
Keyword(s):  
Sodium Chloride ◽  
Surface Energy ◽  
Cohesive Energy ◽  
Classical Model ◽  
Alkali Halides ◽  
Quantum Mechanical Calculation ◽  
Quantum Mechanical ◽  
Mechanical Calculation ◽  
Surface Energies ◽  
First Approximation

Löwdin's theory for the cohesive energy of alkali halides has been used to calculate a first approximation to the surface energy of a {100} face of sodium chloride. The value found, 187 ergs/cm.2, differs from the experimental value determined by measuring heats of solution (276 ergs/cm.2) but is about 18% higher than the figure obtained from a corresponding classical model. For comparison the surface energies of several other alkali halides have been computed.

The effect of particle size on the heat capacity of titanium dioxide

1954 ◽  
Vol 224 (1157) ◽  
pp. 228-235 ◽  
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Heat Capacity ◽  
Titanium Dioxide ◽  
Theoretical Calculations ◽  
Particle Size Effect ◽  
The Other ◽  
Optical Modes ◽  
Modes Of Vibration ◽  
Effect Of Particle Size

The heat capacities of four samples of titanium dioxide, differing in particle size, have been measured in the temperature range 12 to 270° K in order to determine the effect of particle size on the specific heat. Contrary to the prediction of existing theories, no effect attributable to a change in particle size has been found in the low-temperature region. On the other hand, above 50° K a pronounced particle-size effect is evident which may be accounted for qualitatively as an effect on the optical modes of vibration of the solid. The complexity of the titanium dioxide crystal structure precludes any quantitative theoretical calculations.

A LOW TEMPERATURE PARTICLE SIZE EFFECT ON THE HEAT CAPACITY OF SODIUM CHLORIDE

1955 ◽  
Vol 33 (2) ◽  
pp. 240-244 ◽  
Author(s):  
D. Patterson ◽  
J. A. Morrison ◽  
F. W. Thompson
Keyword(s):  
Particle Size ◽  
Heat Capacity ◽  
Sodium Chloride ◽  
Low Temperature ◽  
Size Effect ◽  
Specific Heat ◽  
Significant Contribution ◽  
Particle Size Effect ◽  
Extensive Property ◽  
Effect Of Particle Size

An effect of particle size upon the heat capacity of sodium chloride has been found in the temperature range 9° to 21°K. The experiments were done with three NaCl samples of specific surfaces between 38 and 59 sq. meters per gm. The observed effect has the temperature dependence predicted by theory but its magnitude is three to four times larger than expected. It is unlikely that adsorbed gases have made any significant contribution in the experiments. The accuracy with which the specific heat and surface area differences have been determined is not high enough to show definitely whether or not the surface specific heat is an extensive property of the surface.

Effect of particle size on erosion measurements and predictions in annular flow for an elbow

Wear ◽  
2020 ◽  
pp. 203579
Author(s):  
G. Haider ◽  
M. Othayq ◽  
J. Zhang ◽  
R.E. Vieira ◽  
S.A. Shirazi
Keyword(s):  
Particle Size ◽  
Annular Flow ◽  
Effect Of Particle Size

The Effect of Particle Size and Phospholipid on Growth and Fat Utilization of the Baby Pig

1951 ◽  
Vol 10 (4) ◽  
pp. 867-874 ◽  
Author(s):  
B. E. Sheffy ◽  
Carlos Acevedo Gallegos ◽  
R. H. Grummer ◽  
P. H. Phillips ◽  
G. Bohstedt
Keyword(s):  
Particle Size ◽  
Fat Utilization ◽  
Effect Of Particle Size
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