Project offers

The following projects may be adapted to serve the purpose of a medium term visit, collaboration, degree's final project, master or doctoral thesis. Please note that, unless clearly indicated, there is no implicit funding for a grant.

Imaging fluorescence of fruit

This project is aimed in improving the current CEOT's setup for imaging fluorescence and to clarify some issues not fully solved in previous work.

The setup includes, as usual, light sources, filters and a CCD camera. The first part of the project is to test several leds and filters and evaluate the quality of the results (chlorophyll fluorescence mainly).

In the second part of the work we will address some fundamental questions related with the acquisition of the image: geometrical effects in fruits (the problem is that they are curved), interplay between fluorescence, absorption and reflectance, modelling.

Candidate profile: physics, biology, engineering, informatics. But he/she must be happy to work with some mathematical modelling, not being afraid of connecting two wires and have some computational skills!

Contact: Rui Guerra (rguerra.at.ualg.pt)

Light scattering in fruit

The objective of this project is to determine some properties related with light scattering within fruit tissue. When light enters a fruit, it is scattered by the heterogeneity of the tissue. "Light scattering" means precisely that: photons are scattered in all directions, away from the initial propagation direction. Of course, the way photons are scattered differs a lot from media to media. Classically, the way to characterize light scattering by a given medium is to measure the so called "phase function". You can think of the phase function as a graph where the abscissas are the scattering angle and the ordinates represent the relative intensity of the scattered light. This project is mainly centred on the experimental determination of phase functions for different fruit at different stages of maturation. The relevance of the study is that such phase functions will help understanding the behaviour of light inside the fruit and hence will help improving optical methods for the non-destructive determination of fruit quality. To accomplish the task, we will use a  light scattering  goniometer available at our lab (the picture depicts the setup used in a previous work). Before doing that, however, some instrumentation issues, measurement details and sample preparation procedures must be investigated.

Candidate profile: physics, biology, engineering, informatics. But he/she must be happy to work with some mathematical modelling, not being afraid of connecting two wires and have some computational skills!

Contact: Rui Guerra (rguerra.at.ualg.pt)


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