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- Elsasser, M., et al.
(författare)
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Organic molecular markers and signature from wood combustion particles in winter ambient aerosols: aerosol mass spectrometer (AMS) and high time-resolved GC-MS measurements in Augsburg, Germany
- 2012
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 12:14, s. 6113-6128
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Tidskriftsartikel (refereegranskat)abstract
- The impact of wood combustion on ambient aerosols was investigated in Augsburg, Germany during a winter measurement campaign of a six-week period. Special attention was paid to the high time resolution observations of wood combustion with different mass spectrometric methods. Here we present and compare the results from an Aerodyne aerosol mass spectrometer (AMS) and gas chromatographic - mass spectrometric (GC-MS) analysed PM1 filters on an hourly basis. This includes source apportionment of the AMS derived organic matter (OM) using positive matrix factorisation (PMF) and analysis of levoglucosan as wood combustion marker, respectively. During the measurement period nitrate and OM mass are the main contributors to the defined submicron particle mass of AMS and Aethalometer with 28% and 35%, respectively. Wood combustion organic aerosol (WCOA) contributes to OM with 23% on average and 27% in the evening and night time. Conclusively, wood combustion has a strong influence on the organic matter and overall aerosol composition. Levoglucosan accounts for 14% of WCOA mass with a higher percentage in comparison to other studies. The ratio between the mass of levoglucosan and organic carbon amounts to 0.06. This study is unique in that it provides a one-hour time resolution comparison between the wood combustion results of the AMS and the GC-MS analysed filter method at a PM1 particle size range. The comparison of the concentration variation with time of the PMF WCOA factor, levoglucosan estimated by the AMS data and the levoglucosan measured by GC-MS is highly correlated (R-2 = 0.84), and a detailed discussion on the contributors to the wood combustion marker ion at mass-to-charge ratio 60 is given. At the end, both estimations, the WCOA factor and the levoglucosan concentration estimated by AMS data, allow to observe the variation with time of wood combustion emissions (gradient correlation with GC-MS levoglucosan of R-2 = 0.84). In the case of WCOA, it provides the estimated magnitude of wood combustion emission. Quantitative estimation of the levoglucosan concentration from the AMS data is problematic due to its overestimation in comparison to the levoglucosan measured by the GC-MS.
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| 3. |
- Schnelle, J F, et al.
(författare)
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Reducing and managing restraints in long-term-care facilities.
- 1992
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Ingår i: Journal of The American Geriatrics Society. - 0002-8614 .- 1532-5415. ; 40:4, s. 381-5
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To evaluate a management system designed to improve staff adherence to a federal regulation that stated restrained residents should be released, exercised, and repositioned every 2 hours. DESIGN: A delayed intervention, controlled, cross-over design with three phases. During phase one, baseline, the length of intervals that residents remained in restraints was monitored. The intervention was implemented at site A in Phase two while site B remained in baseline. During Phase three, the intervention was replicated at site B. SETTING: Two long-term care proprietary nursing facilities. PATIENTS: Sixty-three physically restrained residents in the two facilities. INTERVENTION: The intervention was a system of restraint release using colored pads corresponding to specific hours. The management rule was that the resident should be on a different colored pad every 2 hours. Staff had to lift residents to place the pad, and the colors made the system easy for supervisors to check. MAIN OUTCOME MEASURES: Checks by research personnel by black light and invisible ink, to detect movement of the knot tying the restraints. RESULTS: During the baseline phase, the majority of residents at both sites were inappropriately restrained longer than 2 hours (site A: 54.1%; site B: 60.1%). The percentage of residents restrained over 2 hours was significantly reduced during the intervention phase to 13.9% (site A) and 19.4% (site B). Three weeks after the end of the intervention, inappropriate use of restraints remained low, 14.2%, but rose to 47.7% after another 3 weeks. CONCLUSION: The management system is an effective way to increase the consistency with which nursing-home staff release and reposition restrained residents.
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