Oscillatory Rates of Heat Evolution during Sorption of Hydrogen in Palladium

2008 ◽  
Vol 112 (47) ◽  
pp. 18483-18492 ◽  
Author(s):  
Erwin Lalik ◽  
Jerzy Haber ◽  
Aleksander J. Groszek
Keyword(s):  
Heat Evolution

Evaluation of the temperature responses in colorimetric measurements of chemisorption enthalpies on metal films

1979 ◽  
Vol 44 (12) ◽  
pp. 3425-3433 ◽  
Author(s):  
Miloš Smutek ◽  
Slavoj Černý
Keyword(s):  
Heat Evolution ◽  
Adiabatic Temperature ◽  
Time Curve ◽  
Model Calculations ◽  
Colorimetric Measurements ◽  
Reliable Procedure ◽  
Temperature Responses ◽  
Temperature Time ◽  
Zero Time ◽  
Cooling Part

An analysis was performed of various estimates of the adiabatic temperature Ttot that corresponds to the total heat liberated by a gas dose adsorbed on a metal film in the calorimeter for measurement of chemisorption enthalpies. Besides the two common procedures consisting either in the construction of the adiabatic temperature-time curve or in the extrapolation of the single-exponential cooling part of the actual temperature-time curve to zero time, we have examined estimates of Ttot by extrapolating the cooling exponential to the mid-point between zero time and the temperature maximum (t = tmax/2). Model calculations have shown the merit of the latter extrapolation, particularly in the cases of slow heat evolution. This has been verified on the data measured in the chemisorption of methane and ethane on molybdenum films. Extrapolation to tmax/2 has turned out to be a simple and reasonably reliable procedure for handling the data obtained in film calorimeters.

Effect of P2O5 on the Properties of Alite-Calcium Strontium Sulphoaluminate Cement

2011 ◽  
Vol 306-307 ◽  
pp. 961-965
Author(s):  
Chao Nan Yin ◽  
Ling Chao Lu ◽  
Shou De Wang
Keyword(s):  
Compressive Strength ◽  
Electron Microscope ◽  
Heat Evolution ◽  
Petrographic Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sulphoaluminate Cement ◽  
Suitable Amount ◽  
Acceleration Period ◽  
Scanning Electron

The influence of P2O5on the properties of alite-calcium strontium sulphoaluminate cement was researched by means of X-ray diffraction, scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) and petrographic analysis. The results show that the optimal content of P2O5is 0.3% and the compressive strength of the cement at 1, 3, 28d are 27.0, 59.1, 110.9MPa when the calcining temperature is 1350°C. P2O5mainly exists in the belite and a suitable amount of P2O5can promote the formation of C1.5Sr2.5A3and alite. When the content of P2O5is higher than 0.3%, the formation of C1.5Sr2.5A3and alite can be hindered. P2O5can enhance the hydration heat evolution rate in the acceleration period and the hydrate heat of cement containing P2O5increases slightly.

scholarly journals Chilling-Induced Heat Evolution in Plants

1995 ◽  
Vol 108 (3) ◽  
pp. 995-999 ◽  
Author(s):  
M. R. Moynihan ◽  
A. Ordentlich ◽  
I. Raskin
Keyword(s):  
Heat Evolution

Effect of Phosphates on the Hydration Process of Alkali Activated Materials

2016 ◽  
Vol 851 ◽  
pp. 63-68
Author(s):  
Lukáš Kalina ◽  
Vlastimil Bílek Jr. ◽  
Kateřina Komosná ◽  
Radoslav Novotný ◽  
Jakub Tkacz
Keyword(s):  
Electron Microscopy ◽  
Blast Furnace Slag ◽  
Heat Evolution ◽  
Hydration Reaction ◽  
Optimal Dosage ◽  
Initial Setting ◽  
Activated Slag ◽  
The One ◽  
Furnace Slag ◽  
Alkali Activated

The study deals with the one of the important feature of alkali activated blast furnace slag which is very rapid initial setting. Therefore, the influence of the retarding agents such as phosphates was tested. It is shown that phosphates decreases the hydration heat evolution and retards the hydration reaction of alkali activated slag effectively. The mechanism of retardation is studied through the microcalorimeter and electron microscopy equipped with energy dispersive analyzer (SEM-EDS). The optimal dosage of suitable retarding admixture in the means of mechanical properties has been determined.

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