Non-Destructive Spectroscopic Investigations on Paintings Using Optical Fibers

ABSTRACTThe main objective of our research is the development of totally non-destructive methodologies for the investigation of art works. We propose the use of fiber optic reflectance spectroscopy (FORS) in the visible and near-infrared region as a tool for the identification of the pigments used in painting. We have considered several representative inorganic artists' pigments (mainly till the Renaissance period); powder X-ray diffractograms and diffuse reflectance spectra in the visible, near-, middle- and far-infrared range were recorded for pure pigments. Then we prepared suitable samples with the same pigments using fresco, tempera and oil techniques. The visible and near-infrared spectra of these samples were recorded using an optical fiber spectrum analyzer; color analysis (chromaticity, dominant wavelength and purity) was also performed. The obtained results were used in the interpretation of the spectra obtained from some paintings collected in the Uffizi Gallery, Florence (Giotto and Luca Signorelli). The pointwise information obtained by FORS analysis was also used to calibrate and tune an image spectroscopy system, based on sequences of band-pass filtered images in the near infrared range.

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Mid and near Infrared Study of Carbohydrates by Canonical Correlation Analysis

Journal of Near Infrared Spectroscopy ◽

10.1255/jnirs.13 ◽

1993 ◽

Vol 1 (2) ◽

pp. 99-108 ◽

Cited By ~ 13

Author(s):

P. Robert ◽

M.F. Devaux ◽

A. Qannari ◽

M. Safar

Keyword(s):

Correlation Analysis ◽

Infrared Spectra ◽

Canonical Correlation ◽

Near Infrared ◽

Sugar Content ◽

Infrared Region ◽

Total Sugar ◽

Mid Infrared ◽

Total Sugar Content ◽

Near Infrared Spectra

Multivariate data treatments were applied to mid and near infrared spectra of glucose, fructose and sucrose solutions in order to specify near infrared frequencies that characterise each carbohydrate. As a first step, the mid and near infrared regions were separately studied by performing Principal Component Analyses. While glucose, fructose and sucrose could be clearly identified on the similarity maps derived from the mid infrared spectra, only the total sugar content of the solutions was observed when using the near infrared region. Characteristic wavelengths of the total sugar content were found at 2118, 2270 and 2324 nm. In a second step, the mid and near infrared regions were jointly studied by a Canonical Correlation Analysis. As the assignments of frequencies are generally well known in the mid infrared region, it should be useful to study the relationships between the two infrared regions. Thus, the canonical patterns obtained from the near infrared spectra revealed wavelengths that characterised each carbohydrate. The OH and CH combination bands were observed at: 2088 and 2332 nm for glucose, 2134 and 2252 nm for fructose, 2058 and 2278 nm for sucrose. Although a precise assignment of the near infrared bands to chemical groups within the molecules was not possible, the present work showed that near infrared spectra of carbohydrates presented specific features.

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Quantum mechanical simulations of near-infrared spectra of biomolecules – Long-chain fatty acids

NIR news ◽

10.1177/0960336018788631 ◽

2018 ◽

Vol 29 (6) ◽

pp. 13-19 ◽

Cited By ~ 2

Author(s):

Krzysztof B Beć ◽

Justyna Grabska

Keyword(s):

Fatty Acids ◽

Infrared Spectra ◽

Near Infrared ◽

Infrared Region ◽

Quantum Mechanical ◽

Long Chain Fatty Acids ◽

Near Infrared Spectra ◽

Technical Article ◽

Long Chain ◽

Chain Fatty Acids

Exact and in-depth interpretation of near-infrared spectra has often appeared problematic in any case stepping beyond the simplest molecules. The inherent complexity of near-infrared spectra due to the abundance of combination modes and the resulting extensive band overlay frequently limits our comprehension of the spectral bands to vague wavenumber regions in which certain modes likely appear. Coincidently, quantum mechanical simulation of spectra which could offer momentous support in solving such problems has rather been rare in the case of near-infrared region due to practical limitations. Recent years have seen a trending development of accurate and affordable methods of near-infrared spectra simulation. A trend in modelling increasingly complex molecules can be noticed reaching even fairly large biomolecules. In this technical article we overview the most recent accomplishments in the field on the example of long-chain fatty acids and their cyclic dimers, which extend beyond 100 atoms.

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Single crystal polarized spectra in the near-infrared region: a local-mode analysis of the spectra of CsMnCl3•2X2O (X = H, D)

Canadian Journal of Chemistry ◽

10.1139/v94-153 ◽

1994 ◽

Vol 72 (5) ◽

pp. 1211-1217 ◽

Cited By ~ 1

Author(s):

Ian M. Walker ◽

Paul J. McCarthy

Keyword(s):

Hydrogen Bond ◽

Near Infrared ◽

Infrared Region ◽

Chloride Ions ◽

Mode Analysis ◽

Local Mode ◽

Local Modes ◽

Near Infrared Spectra ◽

Parameter Values ◽

Local Mode Analysis

Polarized near-infrared spectra of single crystals of CsMnCl3•2X2O (X = H, D) were recorded at 10 K. Those bands which could be assigned to O—H or O—D stretch overtones were analyzed using local-mode theory specifically adapted for systems having less than C2v symmetry. Both O—H oscillators form nearly linear hydrogen bonds to neighboring chloride ions at different distances. As a result, the local-mode harmonic frequency and anharmonicity parameters show characteristic shifts from their gas-phase values. The parameter values cover an unusually narrow range in this crystal, considering the spread in hydrogen-bond distances. Assignment of stretch overtone bands to specific oscillators in the crystal was made by using the polarization behavior expected of local modes in the oriented gas model. Several of the overtone bands show combinations with lattice modes or low-energy hydrogen-bond modes in unusual detail.

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Construction of dimetal-containing dithiolene and Schiff base conjugated polymer coating: exploiting metal coordination as a design strategy for improving infrared stealth properties

Polymer Chemistry ◽

10.1039/c9py00880b ◽

2019 ◽

Vol 10 (43) ◽

pp. 5839-5848 ◽

Cited By ~ 1

Author(s):

Jingwen Cai ◽

Jianhua Han ◽

Guojia Ma ◽

Xing Liu ◽

Jinyan Wang ◽

...

Keyword(s):

Schiff Base ◽

Conjugated Polymer ◽

Polymer Coating ◽

Near Infrared ◽

Far Infrared ◽

Design Strategy ◽

Polymer Coatings ◽

Metal Coordination ◽

Infrared Range

Dimetal-containing dithiolene and Schiff base conjugated polymer coatings are constructed and exhibit excellent stealth abilities in the NIR (near-infrared) and MFIR (mid–far-infrared) range.

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Application of Visible-Near Infrared Spectra Technique Based on to the Non-Destructive Measurement of the Salmon Quality

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.926-930.961 ◽

2014 ◽

Vol 926-930 ◽

pp. 961-964

Author(s):

Jiao Jiao Yin

Keyword(s):

Infrared Spectra ◽

Near Infrared ◽

Principal Component ◽

Support Vector ◽

Analysis Method ◽

Linear Discriminant ◽

Near Infrared Spectra ◽

Destructive Measurement ◽

Non Destructive

Because the reflectivity of astaxanthin vary in different bands (mainly 400nm-600nm), so we use the visible-near infrared spectra technique to irradiate the salmon. Because in daily life, people grade the salmon flesh with a color card. In this paper, we first use principal component analysis to reduce the dimensionality of the spectral data of salmon, then use linear discriminant analysis method, least squares support vector machine classification method to distinguish the flesh quality. The correct classification rates are 60%and73.3%. The results show that we can use visible – near infrared spectra to distinguish the quality of the salmon which doesn’t be dissected.

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Recent advances in modeling vibrational spectra of food adulterants – Theoretical simulation of IR and NIR bands of melamine

NIR news ◽

10.1177/0960336019847825 ◽

2019 ◽

Vol 30 (4) ◽

pp. 5-10

Author(s):

Krzysztof B Beć

Keyword(s):

Infrared Spectroscopy ◽

Near Infrared ◽

Infrared Region ◽

Spectral Information ◽

Complex Data ◽

Theoretical Simulation ◽

Methods Of Analysis ◽

Near Infrared Spectra ◽

Near Infrared Region ◽

Detection And Quantification

Food safety may be one of the major concerns of the global society in the forthcoming decades. Analytical vibrational spectroscopy is expected to become a major tool used for controlling the food quality at every stage of its production, storage and delivery. Near-infrared and infrared spectroscopy have rapidly been evolving in analytical applications over the last decades with strong hyphenation to numerical and statistical methods of analysis of complex data, which are known as chemometrics. Analytical spectroscopy has reached a remarkable value for both industrial and institutional laboratories nowadays. However, the routinely used methods of analysis do not attempt to interpret the analysed spectral information in physicochemical sense. Therefore, analytical routines seldom take advantage of the molecular background underlying the properties of analysed sample. In the present article, we review the most recent accomplishments that evidence the progress which may be achieved when that background becomes actually available. We focus on the example of infrared and near-infrared spectra simulation applied to melamine, one of the most infamous food adulterant. This sheds light on the correspondences between infrared and near-infrared region observed earlier in the analytical papers dealing with detection and quantification of melamine in food products.

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Single kernel sorting of high and normal oleic acid peanuts using near infrared spectroscopy

Journal of Near Infrared Spectroscopy ◽

10.1177/09670335211053502 ◽

2021 ◽

pp. 096703352110535

Author(s):

Daniel J O’Connor ◽

Roger Meder ◽

Angelo Furtado ◽

Robert J Henry ◽

Graeme C Wright ◽

...

Keyword(s):

Oleic Acid ◽

Near Infrared ◽

Cardiovascular Health ◽

Health Benefit ◽

Oleic Acid Content ◽

High Oleic ◽

Near Infrared Spectra ◽

Non Destructive ◽

High Oleic Peanuts

Peanuts are known to contain nutrients that deliver cardiovascular and health benefits. One such compound is oleic acid, an omega-9 monounsaturated fatty acid, which occurs naturally in peanuts in the concentration range 40–55% m/m, while some varieties are known to contain oleic acid above 75% m/m. These high oleic peanuts have been shown to have cardiovascular health benefit by lowering lipid levels. Breeders are therefore interested in selecting for peanuts with high oleic acid content in a rapid, non-destructive manner. Near infrared spectra acquired on single peanut kernels was used to classify the kernels as either high oleic content or normal, low oleic content, by means of partial least squares discriminant analysis with an overall error rate in classification of 3.3%.

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Surface Investigation of Photo-Degraded Wood by Colour Monitoring, Infrared Spectroscopy, and Hyperspectral Imaging

Journal of Spectroscopy ◽

10.1155/2013/380536 ◽

2013 ◽

Vol 2013 ◽

pp. 1-13 ◽

Cited By ~ 26

Author(s):

Giorgia Agresti ◽

Giuseppe Bonifazi ◽

Luca Calienno ◽

Giuseppe Capobianco ◽

Angela Lo Monaco ◽

...

Keyword(s):

Infrared Spectroscopy ◽

Hyperspectral Imaging ◽

Near Infrared ◽

Infrared Region ◽

Short Wave ◽

Infrared Range ◽

Surface Chemical ◽

Colour Changes ◽

Short Wave Infrared ◽

Near Infrared Range

The aim of this investigation is to study the changes occurring on the surface of poplar wood exposed to artificial irradiation in a Solar Box. Colour changes were monitored with a reflectance spectrophotometer. Surface chemical modifications were evaluated by measuring the infrared spectra. Hyperspectral imaging was also applied to study the surface wood changes in the visible-near infrared and the short wave infrared wavelength ranges. The data obtained from the different techniques were compared to find the possible correlations in order to evaluate the applicability of the Hyperspectral imaging to investigate wood modifications in a non-invasive modality. The study of colour changes showed an important variation due to photo-irradiation which is the greatest change occurring within the first 24 hours. Infrared spectroscopy revealed that lignin degrades mainly in the first 48 hours. Concerning Hyperspectral imaging, the spectral features in the visible-near infrared range are mainly linked to the spectral shape, whereas in the short wave infrared cellulose and lignin affect shape and reflectance levels. The proposed approach showed that a correlation can be established between colour variation and wood degradation in the visible-near infrared range; furthermore in the short wave infrared region surface chemical changes can be assessed.

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Freeform Extrusion Fabrication of Advanced Ceramic Components With Embedded Sapphire Optical Fiber Sensors

Volume 1: Multifunctional Materials; Mechanics and Behavior of Active Materials; Integrated System Design and Implementation; Structural Health Monitoring ◽

10.1115/smasis2016-9270 ◽

2016 ◽

Author(s):

Amir Ghazanfari ◽

Wenbin Li ◽

Ming C. Leu ◽

Jeremy Watts ◽

Yiyang Zhuang ◽

...

Keyword(s):

Optical Fibers ◽

Near Infrared ◽

Tunable Laser ◽

Infrared Region ◽

Fabrication Process ◽

Laser Source ◽

Layer By Layer ◽

Fiber Sensors ◽

Sensor Reading ◽

Ceramic Components

Traditionally, sensors to be integrated into a structural component are attached to or mounted on the component after the component has been fabricated. This tends to result in unsecured sensor attachment and/or serious offset between the sensor reading and the actual status of the structure, leading to performance degradation of the host structure. This paper describes a novel extrusion-based additive manufacturing process that has been developed to enable embedment of sensors in ceramic components during the part fabrication. In this process, an aqueous paste of ceramic particles with a very low amount of binder content (< 1 vol%) is extruded through a moving nozzle to build the part layer-by-layer. In the case of sensor embedment, the fabrication process is halted after a certain number of layers have been deposited. The sensors are placed in their predetermined locations, and the remaining layers are deposited until the part fabrication is completed. Because the sensors are embedded during the fabrication process, they are fully integrated with the part and the aforementioned problems of traditional sensor embedment can be eliminated. The sensors used in this study were made of sapphire optical fibers of 125 and 250 micro-meters diameter and can withstand temperatures up to 1600 °C. After the parts were built, two different drying processes (freeze drying and humid drying) were investigated to dry the parts. The dried parts were then sintered to achieve near theoretical density. Scanning electron microscopy was used to observe the embedded sensors and to detect any possible flaws in the part or embedded sensor. Attenuation of the sensors was measured in near-infrared region (1500–1600 nm wavelength) with a tunable laser source. Raman spectroscopy was performed on the samples to measure the residual stresses caused by shrinkage of the part and its slippage on the fibers during sintering and mismatch between the coefficients of thermal expansion of the fiber and host material. Standard test methods were employed to examine the effect of embedded fibers on the strength and hardness of the parts. The result indicated that the sapphire fiber sensors with diameters smaller than 250 micrometers are able to endure the freeform extrusion fabrication process and also the post-processing without compromising the part properties.

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