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Characterization of Nanoparticles from Spark Ablation
Published in Andreas Schmidt-Ott, Spark Ablation, 2019
AMSs have been used for quite some time, but the AMS continues to improve and to increase its usefulness due to improvements in the separate techniques it relies on. The basic function of an AMS is to obtain mass spectra of aerosol particles by evaporating and ionizing them, to determine their chemical composition, and to get information about their size and shape. In this chapter the AMS will be discussed very briefly, but for the interested reader the description in the book Aerosol Measurement: Principles, Techniques, and Applications [1] is very thorough.
Late Holocene uplift of a coastal terrace near the Akatore Fault, southern New Zealand
Published in New Zealand Journal of Geology and Geophysics, 2021
Dave Craw, Elahe Parvizi, Stephen Read, Ceridwen I. Fraser, Jonathan M. Waters
Remnant organic material, mostly from marine molluscs, preserved on parts of the uplifted Holocene terrace, was collected for radiocarbon dating. Radiocarbon ages were obtained from the Waikato Radiocarbon Laboratory at University of Waikato, Hamilton, New Zealand, and are quoted as conventional ages (after Stuiver and Polach 1977). The marine reservoir calibration of Reimer et al. (2013) was used for mollusc samples. All ages were determined by accelerator mass spectrometry (AMS) on single organic items, and most ages obtained for this study have analytical uncertainties of ca. ±25 years (1 standard deviation; Table 1). No additional local marine reservoir correction was applied as this is small and uncertain for this region (ΔR = c. −17 ± 20; Petchey et al. 2008). Calibrated ages were estimated with ranges for >95% probability.
Metal accumulation in sclerotium grains collected from low pH forest soils
Published in Journal of Environmental Science and Health, Part A, 2021
Khulan Nyamsanjaa, Makiko Watanabe, Nobuo Sakagami, Bolormaa Oyuntsetseg
As grains > 2 mm in diameter have a mass larger than 2 mg,[20] and sclerotia grains from Cenococcum spp. are composed of approximately 50% carbon, it is possible to obtain 14C ages for even a single grain by using accelerator mass spectrometry (AMS) 14C dating measurements,[21] with a 3-MV tandem accelerator at the Institute of Accelerator Analysis Ltd (Shirakawa, Japan). Approximately 2–4 mg of prepared sclerotia from powdered samples of sites IWK, KO, and CH were used for AMS 14C measurement and the 14C ages of samples from MYK and HRZ were obtained from Watanabe et al.[21] and Sakagami et al.,[20] respectively. Results from the 14C dating are represented by Libby age (yBP), where “Modern” assigns dates younger than the Libby’s base year of 1950.[22]
Long-term cultural eutrophication in White and Walden Ponds (Concord, Massachusetts, USA), Thoreau's lakes of light
Published in Lake and Reservoir Management, 2020
J. Curt Stager, Lydia Harvey, Scott Chimileski
Radiocarbon ages were determined for bulk sediment samples from the cores through accelerator mass spectrometry and were converted to calibrated ages with CALIB 7.1 (Table 1; Stuiver and Reimer 1993). Age–depth models representing the last 1–2 centuries (Figure 3) were constructed by measuring 210Pb activity with depth and applying the constant rate of supply model (Appleby and Oldfield 1978). Because the 210Pb profile of the shorter WP-5 core suggested that background activity levels might not have been reached at the base of the core (Figure 3), the age-depth model of WP-2 was considered more reliable and only WP-2 was subjected to more detailed analyses. Organic contents of the sediments in core WP-2 were estimated by percent weight loss on ignition (%LOI) at 500 C (Sutherland 1998, Heiri et al. 2001).