Planck−Benzinger Thermal Work Function:  Determination of the Thermodynamic Stability of Chymotrypsinogen A and Ribonuclease A in Glycerol†

1996 ◽  
Vol 100 (17) ◽  
pp. 7283-7292 ◽  
Author(s):  
Paul W. Chun
1972 ◽  
Vol 27 (5) ◽  
pp. 794-803 ◽  
Author(s):  
R Müller ◽  
W Walcher ◽  
H.-W Wassmuth

AbstractThree methods for the measurement of the change ΔΦ of the work function Φ of a metal surface due to the presence of adsorbed particles (e. g. oxygen) have been developed utilizing the surface ionization of a beam of metal atoms (e. g. In, Sr) as a probe. The experiments have been performed with a mass spectrometer at ultrahigh vacuum.In the first method the temperature dependency of the ion emission current is used for the determination of the work function Φ considering certain limiting conditions. The two other methods which may be applied simultaneously with the first one, involve a direct measurement of ΔΦ by compensating the change of the contact potential by an external voltage: In the second method the contact potential between the ionizing surface and a surrounding reference electrode is used to control the ion optical conditions for the ion emission, whereas in the third method the change in the kinetic energy of the ions caused by a change of the contact potential between the ionizing surface and the entrance slit of the mass spectrometer is used as a measure of ΔΦ


2019 ◽  
Vol 27 (2) ◽  
pp. 69-76
Author(s):  
N. Yu. Filonenko ◽  
A. N. Galdina

In this paper we investigate the phase composition and phase transformations in the Fe-B system alloys with boron content in the range of 9.0–15.0 wt.%. We use microstructural, X-ray diffraction, differential thermal and durometric analyzes to determine the physical properties of the alloys. The experimental findings show that in the as-cast alloy structure there is Fe5B3 phase in small quantities along with FeB monoboride and Fe2B boride. The Fe5B3 phase is formed as a result of the peritectic reaction L+FeB→Fe5B3 at the temperature of 1680 K. The eutectic transformation L→Fe5B3 +Fe2B occurs in the boron concentration range of 8.8–10.5 wt.%. After annealing of the Fe-B alloys at the temperature of 1473 K and cooling with the rate of 102 K/s we observe the occurring of the Fe5B3 phase. To spot an opportunity of the secondary monoboride formation in the alloys under consideration, we calculate the thermodynamic characteristics of stability of the system. Accounting for the contribution of the first degree approximation of high-temperature expansion of thermodynamic potential of FeB iron monoboride in a Fe-B binary alloy enables us to study its thermodynamic stability. It is shown that stability decrease of FeB at 1423 K allows suggesting that at this temperature the phase transformation occurs and this fact correlates to the differential thermal analysis results.


1998 ◽  
Vol 66 (3) ◽  
pp. 225-227
Author(s):  
Yaakov Kraftmakher

1973 ◽  
Vol 17 (1) ◽  
pp. S7-S11 ◽  
Author(s):  
B.E. Nieuwehuys ◽  
O.G. van Aardenne ◽  
W.M.H. Sachtler

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