Thermal Decomposition of Nitrogen Pentoxide at High Temperature

1951 ◽  
Vol 73 (6) ◽  
pp. 2948-2949
Author(s):  
Harold S. Johnston ◽  
Yu-sheng Tao
Keyword(s):  
Thermal Decomposition ◽  
High Temperature ◽  
Nitrogen Pentoxide

scholarly journals High Temperature Degradation Mechanism of Concrete with Plastering Layer

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 398
Author(s):  
Chihao Liu ◽  
Jiajian Chen
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Thermal Decomposition ◽  
Electron Microscope ◽  
High Temperature ◽  
Thermogravimetric Analysis ◽  
Degradation Mechanism ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Scanning Electron

At present, the research on the high temperature degradation of concrete usually focuses on only the degradation of concrete itself without considering the effect of the plastering layer. It is necessary to take into account the influence of the plastering layer on the high temperature degradation of concrete. With an increase in the water/cement ratio, the explosion of concrete disappeared. Although increasing the water/cement ratio can alleviate the cracking of concrete due to lower pressure, it leads to a decrease in the mechanical properties of concrete after heating. It is proved that besides the water/cement ratio, the apparent phenomena and mechanical properties of concrete at high temperature can be affected by the plastering layer. The plastering layer can relieve the high temperature cracking of concrete, and even inhibit the high temperature explosion of concrete with 0.30 water/cement ratio. By means of an XRD test, scanning electron microscope test and thermogravimetric analysis, it is found that the plastering layer can promote the rehydration of unhydrated cement particles of 0.30 water/cement ratio concrete at high temperature and then promote the mechanical properties of concrete at 400 °C. However, the plastering layer accelerated the thermal decomposition of C-S-H gel of concrete with a water/cement ratio of 0.40 at high temperature, and finally accelerate the decline of mechanical property of concrete. To conclude, the low water/cement ratio and plastering layer can delay the deterioration of concrete at high temperature.

scholarly journals The thermal decomposition of nitrogen pentoxide at low pressures

1925 ◽  
Vol 109 (751) ◽  
pp. 526-540 ◽  
Keyword(s):  
Thermal Decomposition ◽  
The Other ◽  
Nitrogen Tetroxide ◽  
Nitrogen Pentoxide ◽  
Other Hand ◽  
Rate Of Reaction ◽  
Reaction Proceeds ◽  
Products Of Reaction ◽  
Glass Surfaces ◽  
Low Pressures

Unimolecular reactions possess a unique interest in that, as Perrin (‘Ann. Physique,’ vol. 11, p. 5, 1919) first pointed out, for the occurrence of such, some type of interaction between radiation and matter must take place. Although such reactions appear to be extremely rare, many physical processes such as evaporation, ionisation in gases at high temperatures and radio-active decay, proceed at rates conforming to a unimolecular law; true chemical reactions which are definitely unimolecular and not pseudo-unimolecular in character are, on the other hand, stated by many ( e. g ., Lowry, ‘Trans. Farad. Soc.,’ vol. 17, p. 596 (1922) ) to be non-existent. In order to substantiate this statement, it is clearly necessary to prove the more complex character of any reaction which satisfies the usual criteria of unimolecular change. The thermal decomposition of gaseous nitrogen pentoxide apparently fulfils these conditions, for Daniels and Johnston (‘J. Am. C. S.,’ vol. 43, p. 53 (1921)) showed that the reaction proceeded according to a unimolecular law over wide ranges of variation of pressure, and Lueck ( ibid ., vol. 44, p. 757 (1922)) obtained practically identical unimolecular constants for the decomposition in solution in carbon tetrachloride and chloroform. On the other hand, Daniels, Wulf and Karrer ( ibid ., vol. 44, p. 2402 (1922) ) suspected the reaction to be autocatalytic, owing to the apparent retardation of the reaction velocity in the presence of ozone, but the experiments of one of us (Hirst, ‘J. C. S.,’ vol. 127, p. 657 (1925), and of White and Tolman (‘J. Am. C. S.’ vol. 47, p. 1,240 (1925)) proved this to be erroneous. In addition, it has been shown that the reaction proceeds uniformly according to the unimolecular law even in the presence of extensive glass surfaces, or of gases which may be either indifferent, such as argon and nitrogen, or the products of reaction, such as nitrogen tetroxide or dioxide or oxygen. The rate of reaction may be expressed in the form - d C/ dt = 4·98 × 10 13 e -24.700/RT . C. Attempts have been made to interpret the experimental results on the hypothesis that the reaction is in reality bimolecular, and only apparently unimolecular in character; but owing to the abnormally large value of the energy of activation, namely, 24,700 calories per gram. molecule, the number of molecules which could be activated per second by inelastic collision, calculated according to the kinetic theory, falls far short of the observed reaction rate, being, in fact, some 10 5 times smaller.

scholarly journals High-temperature heterogeneous catalysis in platinum nanoparticle – molten salt suspensions

2020 ◽  
Vol 10 (3) ◽  
pp. 625-629
Author(s):  
Behzad Tangeysh ◽  
Clarke Palmer ◽  
Horia Metiu ◽  
Michael J. Gordon ◽  
Eric W. McFarland
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
High Temperature ◽  
Heterogeneous Catalysis ◽  
Co Oxidation ◽  
Molten Salt ◽  
Platinum Nanoparticles ◽  
Platinum Nanoparticle ◽  
Oxidation Activity

Suspensions of platinum nanoparticles (PtNPs) were formed in molten LiCl–LiBr–KBr via thermal decomposition of H2PtCl6, and subsequently evaluated for thermal stability and CO oxidation activity.

High temperature direct probe for MS and its use for thermal decomposition monitoring

Vacuum ◽  
2005 ◽  
Vol 80 (1-3) ◽  
pp. 247-252 ◽  
Author(s):  
S. Bohátka ◽  
Gy. Szöo˝r ◽  
Gy. Czél ◽  
É. Balázs
Keyword(s):  
Thermal Decomposition ◽  
High Temperature

Structural, magnetic, and electronic properties of iron selenide Fe6-7Se8 nanoparticles obtained by thermal decomposition in high-temperature organic solvents

2014 ◽  
Vol 141 (4) ◽  
pp. 044704 ◽  
Author(s):  
I. S. Lyubutin ◽  
Chun-Rong Lin ◽  
K. O. Funtov ◽  
T. V. Dmitrieva ◽  
S. S. Starchikov ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
High Temperature ◽  
Electronic Properties ◽  
Organic Solvents ◽  
Iron Selenide

A Study of the Thermal Decomposition of Nitrogen Pentoxide.

1927 ◽  
Vol 31 (10) ◽  
pp. 1572-1580 ◽  
Author(s):  
F. O. Rice ◽  
Dorothy M. Getz
Keyword(s):  
Thermal Decomposition ◽  
Nitrogen Pentoxide
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