scholarly journals Blast Wave Parameters of Liquid Esters of Nitric Acid: Propane-1,2,3-triyl trinitrate, Propane-1,2-diyl Dinitrate, Ethane-1,2-diyl Dinitrate and Methyl Nitrate

2017 ◽  
Vol 14 (2) ◽  
pp. 375-390 ◽  
Author(s):  
Jiri Pachman ◽  
Jakub Selesovsky ◽  
Martin Künzel ◽  
Robert Matyas ◽  
Karel Kubat ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Blast Wave ◽  
Wave Parameters ◽  
Methyl Nitrate

Basicity and acidity promote hydrolysis of methyl nitrate in aqueous aerosols

2020 ◽  
Author(s):  
Fatemeh Keshavarz ◽  
Theo Kurtén ◽  
Hanna Vehkamäki
Keyword(s):  
Nitric Acid ◽  
Nitrous Acid ◽  
Rate Coefficients ◽  
Alkyl Nitrates ◽  
Hydronium Ions ◽  
Hydroxyl Ion ◽  
Solvent Model ◽  
Methyl Nitrate ◽  
Hydrolysis Of ◽  
Aqueous Aerosols

<p>The chemistry of organic nitrates (ONs), also known as alkyl nitrates (RONO<sub>2</sub>), controls the lifetime of nitrogen oxides in continental areas, which in turn affects air quality and varies ozone concentration throughout the troposphere. ONs can be emitted to the troposphere from marine sources. Also, they can be produced in the atmosphere through addition of NO to peroxy radicals or through the reaction of NO<sub>3</sub> radicals with volatile organic compounds. Atmospheric ONs may subsequently undergo oxidation or photolysis, in both gas and aerosol phases, or hydrolysis in aqueous aerosols. Though some recent studies have believed acid-catalysis promotes hydrolysis of ONs, earlier studies have claimed that acids have no effect on ON hydrolysis, and that it is the hydroxyl ion that can improve the hydrolysis process. The limited number of experimental studies performed so far have left this conflict with no appropriate answer, as mechanistic insight and full kinetics details have been partially or completely missing for the studied ONs. We report the detailed mechanism of methyl nitrate hydrolysis in acidic, neutral and basic conditions, in addition to analyzing the degradation of methyl nitrate into formaldehyde and nitrous acid in the presence of water and hydronium ions. According to the potential energy surfaces obtained at the CCSD(T)/cc-pVDZ//ωB97X-D/def2-TZVP level of theory (including the SMD solvent model) along with the rate coefficients estimated using asymmetric Eckart tunneling-corrected transition state theory (TST), mediation of water molecules and hydronium ions hinders degradation of methyl nitrate into formaldehyde and nitrous acid and, in general, this decomposition reaction is kinetically unfavorable. Furthermore, neutral hydrolysis of methyl nitrate is extremely slow with pseudo-first order rate coefficients (k; 298 K and 1 atm) falling below 10<sup>-27</sup> s<sup>-1</sup>. Similarly, hydrolysis of methyl nitrate by hydronium ions is observed to be extremely slow (k < 10<sup>-27</sup> s<sup>-1</sup>). However, under acidic conditions, protonation of methyl nitrate is quite feasible with the protonation Gibbs free energy of -429.1 kJ mol<sup>-1</sup>, at 298 K and 1 atm, and protonated methyl nitrate can hydrolyze into protonated methanol and nitric acid much faster relative to the hydronium ion-based and neutral hydrolysis (k = 3.83 s<sup>-1</sup>). On the other hand, the hydroxyl ions generated under basic conditions can hydrolyze methyl nitrate readily to give methanol and nitric acid (k = 6.63 × 10<sup>3</sup> s<sup>-1</sup>), or formaldehyde, nitrate and water (k = 9.40 × 10<sup>6</sup> s<sup>-1</sup>). In addition, regardless of the limitation on the rate of solvent-phase chemical reactions by the rate of diffusion, basic hydrolysis can produce methoxy ions and nitric acid quite fast (k = 8.95 × 10<sup>9</sup> s<sup>-1</sup>). In other words, methyl nitrate hydrolysis is faster in basic aerosols (i.e. some marine aerosols) and, to a less extent, in highly acidic aqueous aerosols (e.g. haze and urban aerosols).       </p>

Study of the Blast Wave Parameters from Small Scale Explosions

1993 ◽  
Vol 18 (1) ◽  
pp. 11-17 ◽  
Author(s):  
M. M. Ismail ◽  
S. G. Murray
Keyword(s):  
Blast Wave ◽  
Small Scale ◽  
Wave Parameters

Blast Wall Shielding Effectiveness

2017 ◽  
Author(s):  
Jihui Geng ◽  
J. Kelly Thomas
Keyword(s):  
Blast Wave ◽  
High Explosive ◽  
Blast Loading ◽  
Blast Waves ◽  
Shielding Effectiveness ◽  
Wave Shape ◽  
Mitigation Option ◽  
Blast Damage ◽  
Wave Parameters ◽  
Vapor Cloud

Blast walls are frequently considered as a potential mitigation option to reduce the applied blast loading on a building or structure in cases where unacceptably high levels of blast damage are predicted. There are three general explosion types of interest with respect to blast loading: High Explosive (HE), Pressure Vessel Burst (PVB), and Vapor Cloud Explosion (VCE). The blast waves resulting from these explosion types can differ significantly in terms of blast wave shape and duration. The effectiveness of a blast wall depends on these blast wave parameters (shape and duration), as well as the blast wall parameters (e.g., height, width and standoff distance from the protected structure). The effectiveness of a blast wall in terms of mitigating the blast loading on a protected structure depends on the combination of the blast wave and blast wall parameters. However, little guidance is available on the effectiveness of blast walls as a mitigation option for non-HE explosion sources. The purpose of this paper is to characterize the effect of blast wave parameters on the effectiveness of a blast wall and to provide guidance on how to determine whether a blast wall is an effective and practical blast damage mitigation option for a given blast loading.

Temperature-dependent absorption cross-sections of gaseous nitric acid and methyl nitrate

1992 ◽  
Vol 66 (3) ◽  
pp. 313-326 ◽  
Author(s):  
O. Rattigan ◽  
E. Lutman ◽  
R.L. Jones ◽  
R.A. Cox ◽  
K. Clemitshaw ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Cross Sections ◽  
Absorption Cross ◽  
Temperature Dependent ◽  
Dependent Absorption ◽  
Methyl Nitrate

Blast wave parameters at diminished ambient pressure

2015 ◽  
Vol 109 ◽  
pp. 235-240 ◽  
Author(s):  
M.V. Silnikov ◽  
M.V. Chernyshov ◽  
A.I. Mikhaylin
Keyword(s):  
Blast Wave ◽  
Ambient Pressure ◽  
Wave Parameters

scholarly journals THE RELATIONSHIP BETWEEN SELECTED BLAST-WAVE PARAMETERS AND THE RESPONSE OF MAMMALS EXPOSED TO AIR BLAST

1968 ◽  
Vol 152 (1) ◽  
pp. 103-121 ◽  
Author(s):  
Donald R. Richmond ◽  
Edward G. Damon ◽  
E. Royce Fletcher ◽  
I. Gerald Bowen ◽  
Clayton S. White
Keyword(s):  
Blast Wave ◽  
Air Blast ◽  
Wave Parameters ◽  
The Relationship
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