Graduate theses
Current Record: 19 of 195
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Title |
Αφαίρεση βιολογικών επικαθίσεων με χρήση laser και αξιολόγηση της αποτελεσματικότητάς της μέσω φασματοσκοπίας φθορισμού επαγόμενου από LED (LED-induced fluorescence) |
Alternative Title |
Laser-assisted removal of stone biodeterioration and evaluation of its effectiveness by LEDinduced fluorescence spectroscopy |
Author
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Σταμούλη, Νεφέλη
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Thesis advisor
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Πουλή, Παρασκευή
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Reviewer
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Ρακιτζής, Πέτρος
Άγγλος, Δημήτριος
Σαμαρτζής, Πέτρος
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Abstract |
The present work is a study of the laser cleaning methodology of a biodeteriorated mural surface.
The cleaning tests took place on a mural fragment from a church located in Cyprus. In order to
detect the biological components on the fragment’s surface, a portable device that induces
fluorescence through an LED source was used. The fluorescence spectra (LED – IF) were able to
provide semi-quantitative information on the presence of fluorophores before cleaning. The
experimental conditions for spectrum acquisition were explored, considering both LED sources
(440 nm and 375 nm) and measurements on dry and wet surfaces. These preliminary studies
aimed to determine optimal conditions that balance stability and objectivity in measurements.
Fluorescence, being a dynamic process influenced by photosynthetic organisms adapting to
external conditions, posed challenges in quantification.
Laser cleaning experiments were conducted using infrared (1064 nm), visible (532 nm), and
combined wavelengths. The evaluation of cleaning effectiveness was based on the development
of the R ratio, incorporating fluorescence signals from chlorophyll and the substrate after
cleaning. Python programming language was utilized for data processing, fitting a multi-peak
fluorescence model to isolate signal values from chlorophyll and the substrate. The R ratio
allowed for the comparison of cleaning efficiency across different points, categorizing them into
effective, partially effective, and ineffective cleaning outcomes.
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Language |
Greek |
Issue date |
2024-03-29 |
Collection
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School/Department--School of Sciences and Engineering--Department of Physics--Graduate theses
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Type of Work--Graduate theses
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Permanent Link |
https://elocus.lib.uoc.gr//dlib/9/8/c/metadata-dlib-1708936820-222522-16628.tkl
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Views |
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