Cathodic reduction of oxidizing gas generated by low‐temperature decomposition of hydrated calcium hypochlorite for flow cell

Fuel Cells ◽  
2021 ◽  
Author(s):  
Fumihiro Kodera ◽  
Shogo Nakagawa ◽  
Shun Sato ◽  
Hajime Nishimura ◽  
Minoru Umeda
Keyword(s):  
Low Temperature ◽  
Flow Cell ◽  
Cathodic Reduction ◽  
Calcium Hypochlorite ◽  
Temperature Decomposition ◽  
Hydrated Calcium

scholarly journals Vortex Configuration Flow Cell Based on Low-Temperature Cofired Ceramics As a Compact Chemiluminescence Microsystem

2008 ◽  
Vol 80 (14) ◽  
pp. 5320-5324 ◽  
Author(s):  
Núria Ibáñez-García ◽  
Mar Puyol ◽  
Carlos M. Azevedo ◽  
Cynthia S. Martínez-Cisneros ◽  
Francisco Villuendas ◽  
...  
Keyword(s):  
Low Temperature ◽  
Flow Cell ◽  
Cofired Ceramics

Neutron diffraction study of the kinetics of low-temperature martensite decomposition in medium-carbon steel

2021 ◽  
Vol 6 ◽  
pp. 83-87
Author(s):  
A. A. Alekseev ◽  
◽  
S. S. Goncharov ◽  
Keyword(s):  
Solid Solution ◽  
Carbon Steel ◽  
Low Temperature ◽  
Neutron Diffraction ◽  
Supersaturated Solid Solution ◽  
Medium Carbon Steel ◽  
Tempering Temperature ◽  
Medium Carbon ◽  
Temperature Decomposition ◽  
Two Stages

It is found that the low-temperature decomposition of martensite in quenched medium-carbon steel occurs in two stages. In the first stage, the rate of decomposition is higher than that in the subsequent stage. Application of the neutron diffraction method allows the identification of two stages of transformation in the first stage of martensite decomposition. It is shown that the first stage is associated predominantly with carbon segregation at dislocations, and the second, with the outdiffusion of carbon from the supersaturated solid solution with the formation of dispersed particles of metastable carbides. It is shown that the change in the concentration of carbon and, accordingly, the degree of tetragonal lattice of martensite at aging and low tempering occurs to a certain limit, independent of the cooling rate during quenching and tempering temperature. This is due to the establishment of a relative equilibrium between a supersaturated solid solution and fine particles of metastable iron carbide. It is found that the determining process, which leads to a change in the microhardness the low-temperature decomposition, is the out diffusion of carbon from the supersaturated solid solution.

The low temperature thermal decomposition of ammonium perchlorate: nitryl perchlorate as the reaction intermediate

1984 ◽  
Vol 396 (1811) ◽  
pp. 425-440 ◽  
Keyword(s):  
Thermal Decomposition ◽  
Low Temperature ◽  
Ammonium Perchlorate ◽  
Bond Formation ◽  
Covalent Bond ◽  
Subsequent Reaction ◽  
Temperature Decomposition ◽  
Covalent Bond Formation ◽  
Localized Reaction

We identify nitryl perchlorate as the essential intermediate in the low temperature thermal decomposition of ammonium perchlorate AP. Evidence supporting this identification includes the analytical detection of an oxidized nitrogenous species in partly reacted AP and the ability of ammonium nitrate and several other nitrates to markedly reduce the induction period to decomposition of AP and to accelerate the subsequent reaction. It is also shown that the measured rate of the reaction of pure AP is in very satisfactory agreement with that estimated to result from this amount of NO 2 ClO 4 present. This mechanism differs from those currently accepted, in which the controlling process is believed to involve the transfer of either a proton or an electron. Our proposal is based on the known instability of NO 2 ClO 4 at reaction temperature ( ca . 500 K), the enhanced reactivity compared to the ionic alkali perchlorates being ascribed to covalent bond formation O 2 NO─ClO 3 . Subsequent reactions of the products of breakdown of this species, NO + , ClO 3 - and 2O or O 2 , are regarded as capable of oxidizing reactant NH 4 + (→NO 2 + ), thus regenerating the intermediate. Localized reaction in migrating ‘particles’ of fluid NO 2 ClO 4 , advancing through the reactant and leaving a residue of porous NH 4 ClO 4 , explains the unusual, incomplete low temperature decomposition that is characteristic of AP. The article reports comparative kinetic data for the decomposition of pure AP and the reaction initiated by various added nitrates. Rate studies are complemented by scanning electron microscope examinations of the geometry of interface development and the structure of the decomposed salt. From these and analytical results the role of nitryl perchlorate in AP decomposition is discussed.

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