EQUILIBRIUM FRACTIONS FOR AN OXYGEN BEAM (15–50 KEV) IN 17 GASES AND VAPORS

1965 ◽  
Vol 43 (3) ◽  
pp. 404-410 ◽  
Author(s):  
A. B. Wittkower ◽  
P. H. Rose ◽  
R. P. Bastide ◽  
N. B. Brooks ◽  
L. Hopwood
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Neutral Fraction ◽  
Sulphur Hexafluoride

The equilibrium fractions of O−, O+, and O2+ have been measured from 15 to 50 keV for the charge-changing of an O+ beam in the following gases and vapors: hydrogen (H2), helium (He), nitrogen (N2), oxygen (O2), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), nitrous oxide (N2O), deuterium (D2), water (H2O), ammonia (NH3), methane (CH4), sulphur hexafluoride (SF6), butane (C4H10), 2,2-dimethylpropane (C5H12), carbon dioxide (CO2). The neutral fraction, O0, may be inferred from the results.

Ultrasonic relaxation of the vibrational specific heat of carbon dioxide, sulphur hexafluoride, nitrous oxide, cyclo propane and methyl chloride in the liquid state

1958 ◽  
Vol 247 (1249) ◽  
pp. 168-185 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Relaxation Time ◽  
Specific Heat ◽  
Methyl Chloride ◽  
Substantial Part ◽  
Sulphur Hexafluoride ◽  
Single Relaxation Time ◽  
Full Analysis ◽  
Liquid States

Measurements have been made of the ultrasonic absorption and the velocity of propagation in a number of liquefied gases at temperatures from 0 to 50°C and over the frequency range 1 to 50 Mc/s. The observations in liquid carbon dioxide cover the major part of a relaxation region, centred about a frequency of approximately 10 Mc/s, and a full analysis is therefore possible in this case. The results are adequately described in terms of a relaxation of the total vibrational specific heat associated with a single relaxation time. For sulphur hexafluoride, nitrous oxide, cyclo propane and methyl chloride it was not possible to cover a substantial part of the relaxation region. In each case, however, the results are consistent with the assumption that the observed non-classical absorption is entirely due to vibrational relaxation and that the total vibrational specific heat relaxes with a single relaxation time. The corresponding characteristic frequencies are calculated and fall within the range 60 to 250 Mc/s. Comparisons are made between the values of the product, density ( ρ ) times relaxation time at constant temperature (ז T ), in the gaseous and liquid states for the above substances and for others, where adequate data is available. It is found that for a given temperature the ratio ( ρז T ) liquid ( ρז T ) gas is greater than, but close to, unity. It is concluded that vibrational transitions in liquids which are not highly associated occur by the mechanism of binary collisions between molecules. The quantity ( ρז T √ T ) –1 , which can be taken as a measure of the collision efficiency, increases with increasing temperature for non-polar liquids, but appears to depend very little on temperature for highly polar ones.

EQUILIBRIUM FRACTIONS FOR A HYDROGEN-ION BEAM (10–50 keV) IN 17 GASES AND VAPORS

1965 ◽  
Vol 43 (1) ◽  
pp. 96-101 ◽  
Author(s):  
A. B. Wittkower ◽  
R. P. Bastide ◽  
N. B. Brooks ◽  
P. H. Rose ◽  
L. Hopwood
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Water Vapor ◽  
Ion Beam ◽  
Hydrogen Ion ◽  
Sulphur Hexafluoride

The equilibrium fractions for a hydrogen-ion beam have been measured, from 10 to 50 keV, in the following gases or vapors: hydrogen (H2), helium (He), nitrogen (N2), oxygen (O2), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), nitrous oxide (N2O), deuterium (D2), water vapor (H2O), ammonia (NH3), methane (CH4), sulphur hexafluoride (SF6), butane (C4H10), 2,2-dimethylpropane (C5H12), carbon dioxide (CO2).

The radiation-induced formation of excited states of aromatic hydrocarbons in cyclohexane IV. Effect of electron scavengers

1972 ◽  
Vol 328 (1575) ◽  
pp. 497-513 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Excited State ◽  
Excited States ◽  
Ion Pair ◽  
Negative Ion ◽  
Secondary Process ◽  
Recombination Reaction ◽  
Sulphur Hexafluoride ◽  
Ion Recombination

The effects of the electron scavengers nitrous oxide, nitromethane, carbon dioxide, sulphur hexafluoride and chloracetic acid on the yields of naphthalene excited states observed in pulse radiolysis of deaerated naphthalene-cyclohexane solutions have been investigated. The excited-state yields were reduced by all the solutes examined although they showed marked differences in their effects on the formation of singlet and triplet excited naphthalene. It is proposed that in the absence of a second solute naphthalene excited states are produced as a result of electron and positive charge scavenging by naphthalene followed by the ion-recombination reaction Naph + + Naph - -> b s (or b ' s ) 1 Naph* + b t (or b ' s ) 3 Naph*, where b s and b t are the number of singlet and triplet excited states of naphthalene formed initially per geminate ion-pair recombination and b ' s and b t are the corresponding efficiencies per free ion-pair recombination. The concentration dependences of the singlet yield G( 1 Naph)*, the triplet yield formed directly on ion recombination, G( 3 Naph*) r , and the total triplet yield, G( 3 Naph*) = G( 3 Naph*) r + ^ t G( 1 Naph*) reported in parts II and III of this series can be fitted to the expressions G( 1 Naph*) = b ' s G gi {α1/2_ [Naph]1/2 /1+α1/2_[Naph]1/2}{α1/2_ [Naph]1/2 /1+α1/2_[Naph]1/2}, G( 3 Naph*) = B ' t G fi + B t G gi >{α1/2_ [Naph]1/2 /1+α1/2_[Naph]1/2}{α1/2_ [Naph]1/2 /1+α1/2_[Naph]1/2}, using the following parameters: G fi = 0.15, G gi = 3.9, a_ = 3.291/mol, a + = 50001/mol, b 8 = 0.863, b ' s = 1.22, B t = b t + (fi t b s = 1.34 and B ' t = b ' t + (j) t b ' s = 1.89. Of the various competing electron scavengers investigated only the results of the nitromethane system at [CH 3 NO 2 ] > 10 -2 mol/l could be explained solely in terms of a simple competition for free and geminate ions by the two solutes. However, it was found that the nitrous oxide and carbon dioxide systems could be rationalized on a similar model by taking account of possible secondary ion reactions and/or excited state formation as a result of ion recombination between Naph + and the negative ion of the competing scavenger. The secondary process occurring in the sulphur hexafluoride and chloracetic systems are more complex and an empirical fit of the data was not possible.

Tidal rewetting in salt marshes triggers pulses of nitrous oxide emissions but slows carbon dioxide emission

2021 ◽  
Vol 156 ◽  
pp. 108197
Author(s):  
Hollie E. Emery ◽  
John H. Angell ◽  
Akaash Tawade ◽  
Robinson W. Fulweiler
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Salt Marshes ◽  
Carbon Dioxide Emission ◽  
Nitrous Oxide Emissions

scholarly journals Greenhouse gas emissions from the water–air interface of a grassland river: a case study of the Xilin River

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xue Hao ◽  
Yu Ruihong ◽  
Zhang Zhuangzhuang ◽  
Qi Zhen ◽  
Lu Xixi ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Land Use ◽  
Nitrous Oxide ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Ghg Emissions ◽  
Nitrous Oxide Emissions ◽  
Gas Emissions ◽  
Sand Land ◽  
Very High

AbstractGreenhouse gas (GHG) emissions from rivers and lakes have been shown to significantly contribute to global carbon and nitrogen cycling. In spatiotemporal-variable and human-impacted rivers in the grassland region, simultaneous carbon dioxide, methane and nitrous oxide emissions and their relationships under the different land use types are poorly documented. This research estimated greenhouse gas (CO2, CH4, N2O) emissions in the Xilin River of Inner Mongolia of China using direct measurements from 18 field campaigns under seven land use type (such as swamp, sand land, grassland, pond, reservoir, lake, waste water) conducted in 2018. The results showed that CO2 emissions were higher in June and August, mainly affected by pH and DO. Emissions of CH4 and N2O were higher in October, which were influenced by TN and TP. According to global warming potential, CO2 emissions accounted for 63.35% of the three GHG emissions, and CH4 and N2O emissions accounted for 35.98% and 0.66% in the Xilin river, respectively. Under the influence of different degrees of human-impact, the amount of CO2 emissions in the sand land type was very high, however, CH4 emissions and N2O emissions were very high in the artificial pond and the wastewater, respectively. For natural river, the greenhouse gas emissions from the reservoir and sand land were both low. The Xilin river was observed to be a source of carbon dioxide and methane, and the lake was a sink for nitrous oxide.

Nitrous oxide and carbon dioxide emissions from monoculture and rotational cropping of corn, soybean and winter wheat

2008 ◽  
Vol 88 (2) ◽  
pp. 163-174 ◽  
Author(s):  
C F Drury ◽  
X M Yang ◽  
W D Reynolds ◽  
N B McLaughlin
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Winter Wheat ◽  
Carbon Dioxide Emissions ◽  
Crop Residue ◽  
Agricultural Land ◽  
Application Rate ◽  
Climatic Conditions ◽  
Growing Seasons ◽  
Previous Crop

It is well established that nitrous oxide (N2O) and carbon dioxide (CO2) emissions from agricultural land are influenced by the type of crop grown, the form and amount of nitrogen (N) applied, and the soil and climatic conditions under which the crop is grown. Crop rotation adds another dimension that is often overlooked, however, as the crop residue being decomposed and supplying soluble carbon to soil biota is usually from a different crop than the crop that is currently growing. Hence, the objective of this study was to compare the influence of both the crop grown and the residues from the preceding crop on N2O and CO2 emissions from soil. In particular, N2O and CO2 emissions from monoculture cropping of corn, soybean and winter wheat were compared with 2 -yr and 3-yr crop rotations (corn-soybean or corn-soybean-winter wheat). Each phase of the rotation was measured each year. Averaged over three growing seasons (from April to October), annual N2O emissions were about 3.1 to 5.1 times greater in monoculture corn (2.62 kg N ha-1) compared with either monoculture soybean (0.84 kg N ha-1) or monoculture winter wheat (0.51 kg N ha-1). This was due in part to the higher inorganic N levels in the soil resulting from the higher N application rate with corn (170 kg N ha-1) than winter wheat (83 kg N ha-1) or soybean (no N applied). Further, the previous crop also influenced the extent of N2O emissions in the current crop year. When corn followed corn, the average N2O emissions (2.62 kg N ha-1) were about twice as high as when corn followed soybean (1.34 kg N ha-1) and about 60% greater than when corn followed winter wheat (1.64 kg N ha-1). Monoculture winter wheat had about 45% greater CO2 emissions than monoculture corn or 51% greater emissions than monoculture soybean. In the corn phase, CO2 emissions were greater when the previous crop was winter wheat (5.03 t C ha-1) than when it was soybean (4.20 t C ha-1) or corn (3.91 t C ha-1). Hence, N2O and CO2 emissions from agricultural fields are influenced by both the current crop and the previous crop, and this should be accounted for in both estimates and forecasts of the emissions of these important greenhouse gases. Key words: Denitrification, soil respiration, rotation, crop residue

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