Effects of hydration on reactions of O-(H2O)n (n = 0-2). 1. Temperature dependences of rate constants for reactions with oxygen, carbon dioxide, carbon monoxide, nitric oxide, sulfur dioxide, methane, nitrous oxide, and water

1990 ◽  
Vol 94 (21) ◽  
pp. 8193-8197 ◽  
Author(s):  
A. A. Viggiano ◽  
Robert A. Morris ◽  
Carol A. Deakyne ◽  
F. Dale ◽  
John F. Paulson
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Nitrous Oxide ◽  
Sulfur Dioxide ◽  
Rate Constants ◽  
Temperature Dependences

Infrared Spectrophotometric Analysis of Medicinal Gases for Trace Impurities

1976 ◽  
Vol 59 (6) ◽  
pp. 1404-1408
Author(s):  
Wilson L Brannon ◽  
Walter R Benson ◽  
George Schwartzman
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Hydrogen Sulfide ◽  
Sulfur Dioxide ◽  
Spectrophotometric Analysis ◽  
Gas Cell ◽  
Trace Impurities ◽  
Infrared Spectrophotometer ◽  
Low Levels

Abstract The feasibility of examining medicinal gases for trace impurities, using an infrared spectrophotometer in conjunction with a 10 m gas cell, was investigated. Many of the impurities for which the USP includes limits were detected and measured at concentrations at or below those permitted by the USP; these include sulfur dioxide, carbon dioxide, carbon monoxide, and water. However, others (hydrogen sulfide, nitric oxide, and nitrogen dioxide) were not detected at these levels by this technique. Methane was found at low levels in some samples.

scholarly journals Soil–Atmosphere Exchange of Nitrous Oxide, Nitric Oxide, Methane, and Carbon Dioxide in Logged and Undisturbed Forest in the Tapajos National Forest, Brazil

2005 ◽  
Vol 9 (23) ◽  
pp. 1-28 ◽  
Author(s):  
Michael Keller ◽  
Ruth Varner ◽  
Jadson D. Dias ◽  
Hudson Silva ◽  
Patrick Crill ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Land Use ◽  
Nitrous Oxide ◽  
Sandy Loam ◽  
Selective Logging ◽  
National Forest ◽  
Soil Atmosphere ◽  
Brazilian Amazon Region ◽  
Undisturbed Forest

Abstract Selective logging is an extensive land use in the Brazilian Amazon region. The soil–atmosphere fluxes of nitrous oxide (N2O), nitric oxide (NO), methane (CH4), and carbon dioxide (CO2) are studied on two soil types (clay Oxisol and sandy loam Ultisol) over two years (2000–01) in both undisturbed forest and forest recently logged using reduced impact forest management in the Tapajos National Forest, near Santarem, Para, Brazil. In undisturbed forest, annual soil–atmosphere fluxes of N2O (mean ± standard error) were 7.9 ± 0.7 and 7.0 ± 0.6 ng N cm−2 h−1 for the Oxisol and 1.7 ± 0.1 and 1.6 ± 0.3 ng N cm−2 h−1 for the Ultisol for 2000 and 2001, respectively. The annual fluxes of NO from undisturbed forest soil in 2001 were 9.0 ± 2.8 ng N cm−2 h−1 for the Oxisol and 8.8 ± 5.0 ng N cm−2 h−1 for the Ultisol. Consumption of CH4 from the atmosphere dominated over production on undisturbed forest soils. Fluxes averaged −0.3 ± 0.2 and −0.1 ± 0.9 mg CH4 m−2 day−1 on the Oxisol and −1.0 ± 0.2 and −0.9 ± 0.3 mg CH4 m−2 day−1 on the Ultisol for years 2000 and 2001. For CO2 in 2001, the annual fluxes averaged 3.6 ± 0.4 μmol m−2 s−1 on the Oxisol and 4.9 ± 1.1 μmol m−2 s−1 on the Ultisol. We measured fluxes over one year each from two recently logged forests on the Oxisol in 2000 and on the Ultisol in 2001. Sampling in logged areas was stratified from greatest to least ground disturbance covering log decks, skid trails, tree-fall gaps, and forest matrix. Areas of strong soil compaction, especially the skid trails and logging decks, were prone to significantly greater emissions of N2O, NO, and especially CH4. In the case of CH4, estimated annual emissions from decks reached extremely high rates of 531 ± 419 and 98 ± 41 mg CH4 m−2 day−1, for Oxisol and Ultisol sites, respectively, comparable to wetland emissions in the region. We calculated excess fluxes from logged areas by subtraction of a background forest matrix or undisturbed forest flux and adjusted these fluxes for the proportional area of ground disturbance. Our calculations suggest that selective logging increases emissions of N2O and NO from 30% to 350% depending upon conditions. While undisturbed forest was a CH4 sink, logged forest tended to emit methane at moderate rates. Soil–atmosphere CO2 fluxes were only slightly affected by logging. The regional effects of logging cannot be simply extrapolated based upon one site. We studied sites where reduced impact harvest management was used while in typical conventional logging ground damage is twice as great. Even so, our results indicate that for N2O, NO, and CH4, logging disturbance may be as important for regional budgets of these gases as other extensive land-use changes in the Amazon such as the conversion of forest to cattle pasture.

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