NEDONSEL, M Clément (2024) Magnetic biomonitoring of airborne metallic particles, using lichen transplants, at the 16th century Mosteiro dos Jerónimos, Lisbon. PRE - Research Project, ENSTA.

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Abstract

This internship report aims to explain how magnetic measurements can be used to map metallic air pollution spread inside a monastery of the XVIIth century, and to characterize the magnetic carriers of the metallic particles. The proposed work is mainly laboratorial and concerns the magnetic analysis of lichen samples that were exposed for 12 weeks inside the Mosteiro dos Jerónimos and outside in the street. Several measurements were made, and parameters calculated to determine both nature of magnetic minerals present in the samples and how concentrate they are. Three methods were used. The specific mass magnetic susceptibility $\chi$ was measured using the MFK1-FA susceptometer (Multi-function Kappabridge) from AGICO, in order to determine the contribution of all magnetic minerals present in each sample. The Isothermal Remanent Magnetization (IRM) acquisition curves up to 1100 mT and IRM determination at backfields of 100 mT and 300 mT were measured thanks to an ASC Impulse Magnetizer model IM-10-30 and a JR-6 Spinner (AGICO) magnetometer. Finally, the Anhysteretic Remanent Magnetization (ARM), was determined using the Spinner magnetometer and an AF Demagnetizer. The measurements obtained represent semi-quantitative parameters on minerals captured by lichen samples. They were efficient to run a first statistical analysis and to spot differences between samples, but sometimes very sensitive to weather and exposure time.

Item Type:Thesis (PRE - Research Project)
Uncontrolled Keywords:Magnetic susceptibility, Anhysteretic RemanentMagnetization, Isothermal Remanent, Magnetization, ferrimagnetic, magnetite.
Subjects:Earth Sciences and Environmental Engineering
Life Sciences and Engineering
ID Code:10105
Deposited By:Clément NEDONSEL
Deposited On:28 août 2024 18:35
Dernière modification:28 août 2024 18:35

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