scholarly journals Direct Measurement of the Interaction Energy between Solids and Gases. VIII. A High-temperature Calorimeter for the Determination of Heats of Adsorption from Room Temperature to 700 K

1982 ◽  
Vol 55 (8) ◽  
pp. 2572-2575 ◽  
Author(s):  
Kazuo Tsutsumi ◽  
Seiichi Hagiwara ◽  
Yoshio Mitani ◽  
Horoshi Takahashi
2018 ◽  
Vol 165 ◽  
pp. 22022
Author(s):  
Vincent Roué ◽  
Cédric Doudard ◽  
Sylvain Calloch ◽  
Frédéric Montel ◽  
Quentin Pujol D’Andrebo ◽  
...  

The determination of high cycle fatigue (HCF) properties of a material with standard method requires a lot of specimens, and could be really time consuming. The self-heating method has been developed in order to predict S–N–P curves (i.e., amplitude stress – number of cycles to failure – probability of failure) with only a few specimens. So the time-saving advantage of this method has been demonstrated on several materials, at room temperature. In order to reduce the cost and time of fatigue characterization at high temperature, the self-heating method is adapted to characterize HCF properties of a titanium alloy, the Ti-6Al-4V (TA6V), at different temperatures. So the self-heating procedure is adjusted to conduct tests with a furnace. Two dissipative phenomena can be observed on self-heating curves. Because of this, a two-scale probabilistic model with two dissipative mechanisms is used to describe them. The first one is observed for low amplitudes of cyclic loading, under the fatigue limit, and the second one for higher amplitudes where the mechanisms of fatigue damage are activated and are dissipating more energy. This model was developed on steel at room temperature. Even so, it is used to describe the self-heating curves of the TA6V at several temperatures.


1994 ◽  
Vol 48 (11) ◽  
pp. 1442-1450 ◽  
Author(s):  
Patrick J. Medvecz ◽  
Kenneth M. Nichols

Fourier transform infrared absorption spectroscopy has been used for the determination of the line strengths of 41 CO and CO2 absorption lines at temperatures between 295 and 1250 K. The CO vibrational-rotational lines were from the P branch of the fundamental absorption band (2150–1950 cm−1) while the CO2 vibrational-rotational lines were from the far wing of the R branch of the v3 fundamental band (2395–2380 cm−1). The intensities of the lines were measured from absorption spectra recorded in a high-temperature gas cell containing known concentrations of CO/CO2/N2 gas mixtures at atmospheric pressure. Absorption spectra were recorded through the cell with the use of a moderate-resolution Fourier transform infrared spectrometer. The absorption spectra were mathematically corrected for distortions resulting from the finite resolution of the spectrometer and for peak overlap. Line strength measurements were made from the corrected peaks by using the Bouguer-Lambert law and assuming a Lorenztian line profile. The experimentally obtained line strengths were evaluated (1) by statistical calculations, (2) by consideration of the validity of the Bouguer-Lambert assumption for these data, (3) by comparison with existing room-temperature and high-temperature data, and (4) by comparison with theoretical calculations. For CO, the statistical analysis suggests that the reported values have an uncertainty of ±10–12%, which is similar to the observed discrepancies with other reported values at room temperature. At high temperatures, the difference between these data and previously reported data and theoretical predictions is less than 10%. For CO2, the statistical uncertainty associated with the line strength calculations is less than 5%, which is also the approximate level of agreement with existing room-temperature data. For lines with m indicies of 65–89, at high temperatures, the values reported in this work agree within 5 to 10% of theoretical calculations.


1982 ◽  
Vol 21 ◽  
Author(s):  
S. Lefebvre ◽  
F. Bley ◽  
P. Cenedese

ABSTRACTDifferent states of local order have been previously measured at room temperature on water quenched crystal of Ni0.76562 Fe0.235 [1−2]. The Cowley' parameters and the interaction pair potentials in a Clapp and floss approximation have been determined at : 385° C, 470°C, 507°C, 535°C, 685°C that is under and above Tc which is equal to 500°C for this composition.The kinetic of long range order establishment is, in this alloy, very sluggish even near Tc [3]; the kinetic of short range order (SRO) is completely different and may be more complex [4]. In the previous experiments it has been supposed that the state of high temperature was retained during the quench. The following experiments check this hypothesis.


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