0000000000178116
AUTHOR
Martin Seelge
A 2600-year record of past polycyclic aromatic hydrocarbons (PAHs) deposition at Holzmaar (Eifel, Germany)
Polycyclic aromatic hydrocarbons (PAHs) are a proxy for climate- and human-related historical fire activity which has rarely been used beyond 1800 AD. We explored the concentration and composition patterns of PAHs together with other proxies (charcoal, C, N, S, δ13C, δ15N, and δ34S) in a sediment core of Holzmaar as indicators of variations in climate and anthropogenic activity over the past 2600 years. The concentrations of pyrogenic PAHs remained low (< 500 ng g− 1) from the pre-Roman Iron Age (600 BC) until the first significant increases to ca. 1000–1800 ng g− 1 between 1700 and 1750 AD related to regional iron production. The highest increases in pyrogenic PAH concentrations occurred w…
Alignment of cone beam computed tomography data using intra-oral fiducial markers.
This article illustrates a new method to align and merge two partially overlapping volumes each of them generated by cone beam computed tomography (CBCT). The aggregate volume covers a larger area of investigation and is determined by localizing one fixed LEGO brick in both of the primal volumes. Based on the LEGO brick an approximate registration of the volumes is determined. Afterwards we improve the transformation by minimizing the difference in overlapping space. In this paper we present a method which automates these two steps and provides an aligned volume.