scholarly journals A Determination of the Ratio of the Specific Heats of Hydrogen at 18° C. and — 190° C

1917 ◽  
Vol 10 (5) ◽  
pp. 525-540 ◽  
Author(s):  
Margaret Calderwood Shields
Keyword(s):  
Specific Heats

Specific heats of polymer powders by differential scanning calorimetry

1982 ◽  
Vol 60 (14) ◽  
pp. 1853-1856 ◽  
Author(s):  
Eva I. Vargha-Butler ◽  
A. Wilhelm Neumann ◽  
Hassan A. Hamza
Keyword(s):  
Differential Scanning Calorimetry ◽  
Specific Heat ◽  
Scanning Calorimetry ◽  
Temperature Range ◽  
Specific Heats ◽  
Powdered Form ◽  
Polymer Powders

The specific heats of five polymers were determined by differential scanning calorimetry (DSC) in the temperature range of 300 to 360 K. The measurements were performed with polymers in the form of films, powders, and granules to clarify whether or not DSC specific heat values are dependent on the diminution of the sample. It was found that the specific heats for the bulk and powdered form of the polymer samples are indistinguishable within the error limits, justifying the determination of specific heats of powders by means of DSC.

scholarly journals Determination of Prominence Plasma β from the Dynamics of Rising Plumes

2013 ◽  
Vol 8 (S300) ◽  
pp. 94-97 ◽  
Author(s):  
Andrew Hillier ◽  
Richard Hillier ◽  
Durgesh Tripathi
Keyword(s):  
Circular Cylinder ◽  
Fluid Dynamic ◽  
Magnetic Pressure ◽  
Gas Pressure ◽  
Specific Heats ◽  
Dynamic Solution

AbstractObservations of quiescent prominences show rising plumes, dark in chromospheric lines, that propagate from large bubbles. In this paper we present a method that may be used to determine the plasma β (ratio of gas pressure to magnetic pressure) from the rising plumes. Using the classic fluid dynamic solution for flow around a circular cylinder, the compression of the prominence material can be estimated. Application to a prominence gave an estimate of the plasma β as β=0.47−1.13 for a ratio of specific heats of γ=1.4−1.7.

The use of electron gas modification in the evaluation of the vibration frequencies and the specific heat of lithium

1960 ◽  
Vol 259 (1298) ◽  
pp. 361-369 ◽  
Keyword(s):  
Experimental Data ◽  
Phase Transformation ◽  
Electron Gas ◽  
Vibration Frequencies ◽  
Specific Heats ◽  
Air Temperatures ◽  
Set Up ◽  
Good Agreement ◽  
Secular Determinant

A secular determinant for the determination of vibration frequencies of lithium has been set up by Launay’s method which takes the electron gas into account. Theoretical elastic constants have been used in the calculation of the force constants. Frequencies have been calculated for 47 points of the first Brillouin zone which gives the value of 3 x 1000 = 3000 frequencies by symmetry. Specific heats have been calculated by numerical computation in the range 300 to 6°K and show good agreement with the experimental data. The agreement below liquid-air temperatures is surprising in view of the known phase transformation of lithium.

scholarly journals The determination of the specific heat of gases at high temperatures by the sound velocity method II—Carbon dioxide

1936 ◽  
Vol 156 (889) ◽  
pp. 504-517 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Specific Heat ◽  
Sound Velocity ◽  
Quartz Crystal ◽  
Wave System ◽  
Sound Waves ◽  
Heated Tube ◽  
Specific Heats

In a previous paper an account was given of experiments to determine the specific heats of carbon monoxide up to a temperature of 1800° C. by the sound velocity method. The principle of the method employed was the setting up in a heated tube of a stationary train of sound waves; the source of the wave system being a quartz crystal vibrating piezo-electrically at a known frequency.

The use of electron gas modification in the evaluation of the vibration frequencies and the specific heats of sodium and potassium

1961 ◽  
Vol 262 (1308) ◽  
pp. 136-144 ◽  
Keyword(s):  
Low Temperatures ◽  
Electron Gas ◽  
Outer Region ◽  
Low Density ◽  
Vibration Frequencies ◽  
Specific Heats ◽  
A New Technique ◽  
Experimental Values ◽  
Sodium And Potassium

The earlier work on the determination of the specific heats of lithium by the use of deLaunay’s model has been extended to sodium and potassium. A new technique has been introduced in which the contributions of the central and the outer parts of the Brillouin zone to C v are calculated separately from different distribution densities of 8000 and 1000 points per zone, respectively. The agreement between the calculated and the experimental values of C v has been found to be very good except at very low temperatures where the deviations can be ascribed to the presence of phase transformation. The effect of using a finer mesh of points on C v has been examined. In order to get accurate values of C v the density of points in the central region has to be increased considerably. In the outer region, however, a low density of eight points per zone as in Raman’s theory is found to be reasonably satisfactory.

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