Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

You searched for subject:(BBCEAS). One record found.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


University College Cork

1. Chen, Jun. Broadband optical cavity absorption spectroscopy in the near-ultraviolet: applications in atmospheric chemistry.

Degree: 2011, University College Cork

A novel spectroscopic method, incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS), has been modified and extended to measure absorption spectra in the near-ultraviolet with high sensitivity. The near-ultraviolet region extends from 300 to 400 nm and is particularly important in tropospheric photochemistry; absorption of near-UV light can also be exploited for sensitive trace gas measurements of several key atmospheric constituents. In this work, several IBBCEAS instruments were developed to record reference spectra and to measure trace gas concentrations in the laboratory and field. An IBBCEAS instrument was coupled to a flow cell for measuring very weak absorption spectra between 335 and 375 nm. The instrument was validated against the literature absorption spectrum of SO2. Using the instrument, we report new absorption cross-sections of O3, acetone, 2-butanone, and 2-pentanone in this spectral region, where literature data diverge considerably owing to the extremely weak absorption. The instrument was also applied to quantifying low concentrations of the short-lived radical, BrO, in the presence of strong absorption by Br2 and O3. A different IBBCEAS system was adapted to a 4 m3 atmosphere simulation chamber to record the absorption cross-sections of several low vapour pressure compounds, which are otherwise difficult to measure. Absorption cross-sections of benzaldehyde and the more volatile alkyl nitrites agree well with previous spectra; on this basis, the cross-sections of several nitrophenols are reported for the first time. In addition, the instrument was also used to study the optical properties of secondary organic aerosol formed following the photooxidation of isoprene. An extractive IBBCEAS instrument was developed for detecting HONO and NO2 and had a sensitivity of about 10-9 cm-1. This instrument participated in a major international intercomparison of HONO and NO2 measurements held in the EUPHORE simulation chamber in Valencia, Spain, and results from that campaign are also reported here. Advisors/Committee Members: Venables, Dean S., SFI.

Subjects/Keywords: BBCEAS; Near-ultraviolet; Cross-section; Broadband cavity enhanced absorption spectroscopy; Spectroscopy; Atmospheric chemistry; Spectrum analysis; Absorption spectra

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Chen, J. (2011). Broadband optical cavity absorption spectroscopy in the near-ultraviolet: applications in atmospheric chemistry. (Thesis). University College Cork. Retrieved from http://hdl.handle.net/10468/435

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Chen, Jun. “Broadband optical cavity absorption spectroscopy in the near-ultraviolet: applications in atmospheric chemistry.” 2011. Thesis, University College Cork. Accessed January 19, 2021. http://hdl.handle.net/10468/435.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Chen, Jun. “Broadband optical cavity absorption spectroscopy in the near-ultraviolet: applications in atmospheric chemistry.” 2011. Web. 19 Jan 2021.

Vancouver:

Chen J. Broadband optical cavity absorption spectroscopy in the near-ultraviolet: applications in atmospheric chemistry. [Internet] [Thesis]. University College Cork; 2011. [cited 2021 Jan 19]. Available from: http://hdl.handle.net/10468/435.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chen J. Broadband optical cavity absorption spectroscopy in the near-ultraviolet: applications in atmospheric chemistry. [Thesis]. University College Cork; 2011. Available from: http://hdl.handle.net/10468/435

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.