| Thermal desorption and vapor transport characteristics in an explosive trace detector. | |
| | |
MedLine Citation:
|
PMID: 21837352 Owner: NLM Status: Publisher |
Abstract/OtherAbstract:
|
Swipe-based explosive trace detectors rely on thermal desorption to vaporize explosive particles collected on a swipe. The vaporized material is carried by air flows from the desorption unit to the inlet of the chemical analyzer, typically an ion mobility spectrometer. We have observed that the amount of explosives detected from a swipe varies with the physical location of explosives collected on the swipe. There are two issues that may contribute to this effect: inhomogeneous or insufficient heating of the swipe during desorption and low velocity air flows that inefficiently transport desorbed vapor during the instruments analysis time. To better characterize this effect, we have simulated the air movements within a generic desorption unit using commercially available computational fluid dynamics software. Simulations are three dimensional, symmetric and solved under steady, laminar flow conditions. The calculated velocity field correlates directly with experimental detector response to the high explosive RDX. Results suggest that the limiting factor in this model thermal desorption unit is the flow-field around the swipe and flow rate into the detector, rather than heat transfer to the swipe itself. Buoyancy effects due to heating dominate the flow-field and produce a vertical bulk fluid motion within the domain that opposes much of the flow drawn into the analyzer. |
| | |
Authors:
|
Matthew E Staymates; Wayne J Smith; Eric Windsor |
Publication Detail:
|
Type: JOURNAL ARTICLE Date: 2011-8-11 |
Journal Detail:
|
Title: The Analyst Volume: - ISSN: 1364-5528 ISO Abbreviation: - Publication Date: 2011 Aug |
Date Detail:
|
Created Date: 2011-8-12 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 0372652 Medline TA: Analyst Country: - |
Other Details:
|
Languages: ENG Pagination: - Citation Subset: - |
Affiliation:
|
National Institute of Standards and Technology, Gaithersburg, MD, USA. matthew.staymates@nist.gov. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Novel second-harmonic-generation-active lead(ii) phosphinate based on 2-carboxyethyl(phenyl)phosphin...
Next Document: Organophosphine/phosphite stabilized disilver(i) methanedisulphonates: synthesis, solid state struct...