Phase behaviour of ammonia, nitric acid and particulate ammonium nitrate: The influence of the aerosol characteristics

1992 ◽  
Vol 23 ◽  
pp. 941-944 ◽  
Author(s):  
G. Lammel ◽  
G. Pohlmann
1979 ◽  
Vol 13 (11) ◽  
pp. 1416-1419 ◽  
Author(s):  
George J. Doyle ◽  
Ernesto C. Tuazon ◽  
Richard A. Graham ◽  
Thomas M. Mischke ◽  
Arthur M. Winer ◽  
...  

Author(s):  
Ralph Dlugi ◽  
Lucia Kins ◽  
Thomas Seiler ◽  
Winfried Seidl ◽  
Peter Seifert ◽  
...  

2010 ◽  
Vol 3 (1) ◽  
pp. 187-208 ◽  
Author(s):  
V. Wolff ◽  
I. Trebs ◽  
C. Ammann ◽  
F. X. Meixner

Abstract. The aerodynamic gradient method is widely used for flux measurements of ammonia, nitric acid, particulate ammonium nitrate (the NH3-HNO3-NH4NO3 triad) and other water-soluble reactive trace compounds. The surface exchange flux is derived from a measured concentration difference and micrometeorological quantities (turbulent exchange coefficient). The significance of the measured concentration difference is crucial for the significant determination of surface exchange fluxes. Additionally, measurements of surface exchange fluxes of ammonia, nitric acid and ammonium nitrate are often strongly affected by phase changes between gaseous and particulate compounds of the triad, which make measurements of the four individual species (NH3, HNO3, NH4+, NO3− necessary for a correct interpretation of the measured concentration differences. We present here a rigorous analysis of results obtained with a multi-component, wet-chemical instrument, able to simultaneously measure gradients of both gaseous and particulate trace substances. Basis for our analysis are two field experiments, conducted above contrasting ecosystems (grassland, forest). Precision requirements of the instrument as well as errors of concentration differences and micrometeorological exchange parameters have been estimated, which, in turn, allows the establishment of thorough error estimates of the derived fluxes of NH3, HNO3, NH4+, and NO3−. Derived median flux errors for the grassland and forest field experiments were: 39% and 50% (NH3), 31% and 38% (HNO3), 62% and 57% (NH4+), and 47% and 68% (NO3−), respectively. Additionally, we provide the basis for using field data to characterize the instrument performance, as well as subsequent quantification of surface exchange fluxes and underlying mechanistic processes under realistic ambient measurement conditions.


1953 ◽  
Vol 31 (3) ◽  
pp. 201-203
Author(s):  
R. H. Betts ◽  
R. S. Stuart ◽  
C. A. Winkler

An electrometric method for determination of nitric acid in RDX(B) liquors has been developed. The method is not largely affected by ammonium nitrate and acetic anhydride. A precision of ± 0.5% may be readily obtained. Acetic anhydride in RDX(B) liquors may be determined by direct titration with standard aniline–toluene solution at 0 °C., using calcium hypochlorite as an external indicator. In routine analysis, a precision of ± 2% may be obtained.


1951 ◽  
Vol 29 (8) ◽  
pp. 642-645 ◽  
Author(s):  
H. L. Williams ◽  
C. A. Winkler

The effect of varying the concentrations of nitric acid and ammonium nitrate on the yield of RDX has been determined at 35°C., using hexamine, hexamine mononitrate, and hexamine dinitrate. The activation energies for the formation of RDX from hexamine, hexamine mononitrate, and hexamine dinitrate were found to be approximately 11 kcal., 12.5 kcal., and 16.5 kcal., respectively.


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