Decomposition of water behind reflected shock waves

Bopp, J. M.; Kern, R. D.; Niki, T.

doi:10.1021/j100501a004

Cited by 6 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If the previous studies are compared, the results of Homer and Hurle 3 are about a factor of 2 higher than both studies based on water depletion 2,4. Taking into account the enhancement due to H 2 O–H 2 O collisions with the dilutions used in this work, the present results for k 1,M , given in Table I, will have only a 5–10% water contribution.…”

Section: Discussionmentioning

confidence: 55%

“…Although Olschewski et al 2 were able to use infrared emission of water at 2.8 μm to measure [H 2 O] t , their experiments, using optical absorption of OH, were not successful in measuring the dissociation rate constant, again probably due to secondary reactions. Bopp et al 4 also used infrared emission to observe D 2 O dissociation but made no attempt to estimate isotope effects. The experiments by Cathro and Mackie 5 contained ∼8–10% H 2 O and relied on the assumption of equilibrium in the reaction, Li + H 2 O = LiOH + H. Considering all previous studies, the experiments of Homer and Hurle 3 appear to be the most thorough even though the delayed flash absorption of OH required extraordinary control over shock strengths in successive experiments.…”

Section: Discussionmentioning

confidence: 99%

“…Because it is important in H 2 /O 2 flame chemistry, the thermal decomposition of H 2 O has been studied five times 1–5. The direct studies, either by observing H 2 O depletion 2,4 or by OH‐radical formation 1–3, have been confined to relatively large [H 2 O] 0 at temperatures above ∼ 2700 K because the sensitivity for detection has been relatively low. We have recently described a multipass optical system that allows for the detection of OH‐radicals in concentrations between ∼ 2 × 10 12 and 2 × 10 14 molecules cm −3 6.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The thermal decomposition of water

Srinivasan

Michael

2006

Int J of Chemical Kinetics

View full text Add to dashboard Cite

The reflected shock tube technique with multipass absorption spectrometric detection of OH-radicals at 308 nm, corresponding to a total path length of 1.749 m, has been used to study the reaction H 2 O + M → H + OH + M between 2196 and 2792 K using 0.3, 0.5, and 1% H 2 O, diluted in Kr. As a result of the increased sensitivity for OH-radical detection, the existing database for this reaction could be extended downward by ∼500 K. Combining the present work with that of Homer and Hurle, the composite rate expression for water dissociation in either Ar or Kr bath gas is k 1,Ar(or Kr) = (2.43 ± 0.57) × 10 −10 exp(−47117 ± 633 K/T) cm 3 molecule −1 s −1 over the T-range of 2196-3290 K. Applying the Troe factorization method to data for both forward and reverse reactions, the rate behavior could be expressed to within <±18% over the T-range, 300-3400 K, by the three-parameter expression k 1,Ar = 1.007 × 10 4 T −3.322 exp(−60782 K/T) cm 3 molecule −1 s −1 A large enhancement due to H 2 O with H 2 O collisional activation has been noted previously, and both absolute and relative data have been considered allowing us to suggest k 1,H 2 O = 1.671 × 10 2 T −2.440 exp(−60475 K/T) cm 3 molecule −1 s −1 for the rate constants with H 2 O bath gas over the T-range,

show abstract

Section: Discussionmentioning

confidence: 55%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The thermal decomposition of water

Srinivasan

Michael

2006

Int J of Chemical Kinetics

View full text Add to dashboard Cite

show abstract

“…Chromospheric activity, however, can be immediately ruled out, because it causes very weak Hα emission for stars earlier than spectral type M2, with equivalent widths typically of order −1 Å (e.g. Bopp & Talcott 1978;Bopp & Schmitz 1978). Precisely, it is to keep our sample free from objects of this type that, following White & Basri (2003), we only consider stars with W eq (Hα) < −10 Å.…”

Section: Searching For Pre-main Sequence Starsmentioning

confidence: 99%

Photometric Determination of the Mass Accretion Rates of Pre-Main-Sequence Stars. Iv. Recent Star Formation in NGC 602

Marchi

Beccari

Panagia

2013

ApJ

View full text Add to dashboard Cite

We have studied the young stellar populations in NGC 602, in the Small Magellanic Cloud, using a novel method that we have developed to combine Hubble Space Telescope photometry in the V , I, and Hα bands. We have identified about 300 pre-main sequence (PMS) stars, all of which are still undergoing active mass accretion, and have determined their physical parameters (effective temperature, luminosity, age, mass and mass accretion rate). Our analysis shows that star formation has been present in this field over the last 60 Myr. In addition, we can recognise at least two clear, distinct, and prominent episodes in the recent past: one about 2 Myr ago, but still ongoing in regions of higher nebulosity, and one (or more) older than 30 Myr, encompassing both stars dispersed in the field and two smaller clusters located about 100 north of the centre of NGC 602. The relative locations of younger and older PMS stars do not imply a causal effect or triggering of one generation on the other. The strength of the two episodes appears to be comparable, but the episode occurring more than 30 Myr ago might have been even stronger than the current one. We have investigated the evolution of the mass accretion rateṀ acc as a function of the stellar parameters finding that logṀ acc −0.6 logt + log m + c, where t is the age of the star, m its mass and c is a decreasing function of the metallicity.

show abstract