| 1. |
- Yafa, C., et al.
(författare)
-
Development of an ombrotrophic peat bog (low ash) reference material for the determination of elemental concentrations
- 2004
-
Ingår i: Journal of Environmental Monitoring. - : Royal Society of Chemistry (RSC). - 1464-0325 .- 1464-0333. ; 6:493, s. 501-
-
Tidskriftsartikel (refereegranskat)abstract
- Given the increasing interest in using peat bogs as archives of atmospheric metal deposition, the lack of validated sample preparation methods and suitable certified reference materials has hindered not only the quality assurance of the generated analytical data but also the interpretation and comparison of peat core metal profiles from different laboratories in the international community. Reference materials play an important role in the evaluation of the accuracy of analytical results and are essential parts of good laboratory practice. An ombrotrophic peat bog reference material has been developed by 14 laboratories from nine countries in an inter-laboratory comparison between February and October 2002. The material has been characterised for both acid-extractable and total concentrations of a range of elements, including Al, As, Ca, Cd, Cr, Cu, Fe, Hg, Mg, Mn, Na, Ni, P, Pb, Ti, V and Zn. The steps involved in the production of the reference material (i.e. collection and preparation, homogeneity and stability studies, and certification) are described in detail.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Russell, Adrian P., et al.
(författare)
-
Instruments for a European Extremely Large Telescope: the challenges of designing instruments for 30- to 100-m telescopes
- 2004
-
Ingår i: Ground-based instrumentation for astronomy (Proceedings of the SPIE). - : SPIE. - 0819454249 ; 5492, s. 1796-1809
-
Konferensbidrag (refereegranskat)abstract
- Designs for Extremely Large Telescopes (ELTs) are quite well advanced,but the requirements of instruments have had limited impact. Sinceprovision of a suitable environment for instruments is a critical aspectof all telescopes, we outline some well-known and some less-appreciatedchallenges of designing instruments for ELTs. A wide-field spectrometer(WFSPEC) with ~10 arcmin field-of-view, probably with AO correction ofground-layer seeing, illustrates the well-known difficulty of matchingmodern detector pixels to large (~0."3) images. The challenges ofexploiting wide-field (1'-2' FOV) high-performance AO systems on ELTsare illustrated by a Multi-Object Multi-field Spectrometer and Imager(MOMSI), which provides imaging and integral-field spectroscopy, atnear-diffraction-limited pixel scales, of targets in approximately 300subfields each. This instrument, roughly equivalent to all theastronomical spectrometers yet built, extracts ~200 times less of theavailable information from the ELT's FOV than near-future instruments on8-m class telescopes will do for their hosts. We emphasise the greatsize of such instruments (40-100 tonnes, 100-200 m3) and the need toaccommodate this size in telescope plans. A third area of challenge isthe exploitation of the potential capabilities of ELTs in the mid-IR,where they would offer powerful complements to JWST and ALMA;low-emissivity telescope designs and, possibly, cryogenic AO, may beneeded. Finally, we outline the potential challenges of correctingatmospheric dispersion effects.
|
|
