FIBRE OPTIC BRAGG STRUCTURES WITH MONOTONIC APODISATION CHARACTERISTICS

Jacek Klimek

doi:10.35784/iapgos.2828

FIBRE OPTIC BRAGG STRUCTURES WITH MONOTONIC APODISATION CHARACTERISTICS

Informatyka Automatyka Pomiary w Gospodarce i Ochronie Środowiska ◽

10.35784/iapgos.2828 ◽

2021 ◽

Vol 11 (4) ◽

pp. 42-46

Author(s):

Jacek Klimek

Keyword(s):

Mathematical Modelling ◽

Spectral Features ◽

Fibre Optic ◽

Bragg Structures

The article discusses the principle of operation and the structure of chirped and uniform gratings. It presents the method of producing gratings with monotonic apodisation characteristics, and compares the spectral features of produced gratings with the those obtained by mathematical modelling.

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Predicting extra virgin olive oil freshness during storage by fluorescence spectroscopy

Grasas y Aceites ◽

10.3989/gya.0332171 ◽

2018 ◽

Vol 68 (4) ◽

pp. 219 ◽

Cited By ~ 9

Author(s):

R. Aparicio-Ruiz ◽

N. Tena ◽

I. Romero ◽

R. Aparicio ◽

D. L. García-González ◽

...

Keyword(s):

Mathematical Modelling ◽

Shelf Life ◽

Olive Oil ◽

Oil Quality ◽

Virgin Olive Oil ◽

Extra Virgin Olive Oil ◽

Spectral Features ◽

Olive Oil Quality ◽

Over Time

Virgin olive oil quality relates to flavor and unique health benefits. Some of these properties are at the most desirable level when the oil is just extracted, since it is not a product that improves with age. On the contrary, the concentrations of many compounds change during its shelf-life. These changes reveal the aging of the oil but do not necessarily mean decay in sensory properties, so in some cases an aged oil from healthy olives may be better qualified than a fresh one from olives affected by fermentation. The aim of this work is to analyze different methodologies proposed for assessing the quality of virgin olive oil with implications in freshness and aging of the oil, and to highlight the possibilities of rapid spectrofluorimetric techniques for assessing oil freshness by checking the evolution of pigments during storage. The observed change in the selected spectral features and mathematical modelling over time was compared with the accepted model for predicting the amount of pyropheophytin a, which is based on isokinetic studies. The best regression was obtained for 655 nm (adjusted-R2 = 0.91) wavelength, which matches the distinctive band of pigments. The two mathematical models described in this study highlight the usefulness of pigments in the prediction of the shelf-life of extra virgin olive oil.

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