Linked Life Data

10473201

Source:http://linkedlifedata.com/resource/pubmed/id/10473201

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1999-10-13
pubmed:abstractText
Oxygen contamination of a polyacrylamide gel (PAG) dosimeter can have a significant detrimental effect upon the performance characteristics of the gel as a dosimeter. Oxygen contamination can occur during preparation, but can also arise from the diffusion of atmospheric oxygen through vessel walls. Even 'trace' amounts of oxygen present in any gaseous space (usually nitrogen filled) between the surface of the PAG and the vessel seal can have a detectable effect. This paper describes a method used to quantify the detrimental effects of a range of oxygen concentrations upon the performance of the PAG. The results of diffusion studies for air and pure oxygen diffusing into the PAG over time are presented and coupled with a novel method of calculating oxygen concentrations in the PAG. Results obtained suggest that the diffusion is Fickian. The coefficient of diffusion D has been calculated to be (8+/-2) x 10(-6) cm2 s(-1) for oxygen diffusing into PAG stored at 4 degrees C, under the assumption that the diffusion mechanism is independent of the concentration of the diffusing species. In addition, a quantitative relation has been established between the transverse relaxation rate R2 of the PAG and the concentration of oxygen present. The implications of these findings for polymer gel dosimetry are discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0031-9155
pubmed:author
pubmed:issnType
Print
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1875-84
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Dynamics of polymerization in polyacrylamide gel (PAG) dosimeters: (II) modeling oxygen diffusion.
pubmed:affiliation
Department of Physics, University of Surrey, Guildford, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't