Showing papers on "Atmospheric methane published in 1968"
TL;DR: In these studies a constant-infusion technique ordinarily used for the study of intestinal absorption of liquids was modified to obtain quantitative data on human intestinal gas production.
Abstract: For many years it has been known that hydrogen and methane are produced by bacteria and that these gases may be present in high concentration in flatus. Recently, Nielsen has developed methods to measure hydrogen and methane in expired air,l and Calloway has related the breath hydrogen concentration to the ingestion of certain foods.2 There are, however, few data on the site and rate of formation of H2 and CH4 in man. In our studies a constant-infusion technique ordinarily used for the study of intestinal absorption of liquids was modified to obtain quantitative data on human intestinal gas production.
134 citations
TL;DR: Measurements of atmospheric CO concentrations in California, Greenland, and Oregon seem to indicate that CO content is an air mass characteristic, while the air mass over continental California seems to be characterized by CO levels of 0.5-1.0 ppm or greater.
Abstract: A carbon monoxide analyzer has been developed which is capable of continuous measurement of the carbon monoxide concentration in the atmosphere. The operating principle of the instrument is the reaction of carbon monoxide with hot mercuric oxide followed by the photometric determination of the mercury vapor produced. Oxygenated hydrocarbons and olefins are quantitatively detected. Those normally present are in the ambient atmosphere in low concentrations relative to CO. Hydrogen and methane in the atmosphere do not interfere with the CO analysis. Measurements of atmospheric CO concentrations in California, Greenland, and Oregon seem to indicate that CO content is an air mass characteristic. North Pacific marine air mass concentrations may be as low as about 0.040 parts per million (ppm) CO, while the air mass over continental California seems to be characterized by CO levels of 0.5-1.0 ppm or greater.
84 citations
TL;DR: In this paper, the tritium concentration in the northern hemisphere has been essentially constant since 1958, the time the first samples were analyzed, which can best be explained by assuming that leakage of tritiated methane into the atmosphere from sources in nuclear industry located in the North American region for a period of years prior to 1958, and then the leak was essentially closed.
Abstract: Ten samples of atmospheric methane collected at Oberhausen, Germany, and Gary, Indiana, between 1960 and 1963 have been analyzed for their tritium and deuterium content. The results show the tritium concentration in the northern hemisphere to have been essentially constant since 1958, the time the first samples were analyzed. Existing theories to explain the origin of tritiated methane are discussed and rejected as highly improbable. The data can best be explained by assuming that leakage of tritiated methane into the atmosphere from sources in nuclear industry located in the northern hemisphere occurred for a period of years prior to 1958, and then the leak was essentially closed.
13 citations
TL;DR: In this article, the tritium content of liquid oxygen collected at ground level near Neosho, Missouri has been measured and the fluctuation of the T/H ratio in these samples is discussed in terms of possible sources of this radioactivity.
Abstract: Samples of liquid oxygen collected at ground level near Neosho, Missouri, have been processed for recovery of methane, and the tritium content of these samples has been measured. The fluctuation of the T/H ratio in these samples is discussed in terms of possible sources of this radioactivity. Arguments that this tritium-labeled methane has been released from sources in nuclear industry are supported by measurements of tritium in ethane recovered from some of these liquid oxygen samples. The continuing release of labeled methane by nuclear industry is suggested by the fact that the T/H ratio has not changed appreciably during the period 1958 to 1966, although this interval is comparable to the chemical lifetime expected for methane in the atmosphere.
6 citations