scholarly journals Remote Laser Induced Fluorescence of Soils and Rocks

Photonics ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 411
Author(s):  
Vasily N. Lednev ◽  
Alexey F. Bunkin ◽  
Sergey M. Pershin ◽  
Mikhail Ya. Grishin ◽  
Diana G. Artemova ◽  
...  
Keyword(s):  
Fluorescence Spectroscopy ◽  
Fluorescence Spectra ◽  
Space Exploration ◽  
Laser Induced Fluorescence ◽  
Excitation Wavelength ◽  
Extraterrestrial Life ◽  
Future Space ◽  
Lidar Sensing ◽  
First Time ◽  
Different Soils

The laser induced fluorescence spectroscopy was systematically utilized for remote sensing of different soils and rocks for the first time, to the best of our knowledge. Laser induced fluorescence spectroscopy measurements were carried out by the developed nanosecond LIDAR instrument with variable excitation wavelength (355, 532 and 1064 nm). LIDAR sensing of different Brazil soil samples have been carried out in order to construct a spectral database. The laser induced fluorescence spectra interpretation for different samples has been discussed in detail. The perspectives of LIDAR sensing of organic samples deposited at soils and rock have been discussed including future space exploration missions in the search for extraterrestrial life.

scholarly journals Assisted Interpretation of Laser-Induced Fluorescence Spectra of Egg-Based Binding Media Using Total Emission Fluorescence Spectroscopy

2006 ◽  
Vol 2006 ◽  
pp. 1-5 ◽  
Author(s):  
Austin Nevin ◽  
Demetrios Anglos
Keyword(s):  
Amino Acids ◽  
Fluorescence Spectroscopy ◽  
Fluorescence Spectra ◽  
Emission Spectra ◽  
Egg Yolk ◽  
Laser Induced Fluorescence ◽  
Oxidation Products ◽  
Total Emission ◽  
Binding Media ◽  
Age Related

Laser-induced fluorescence (LIF) spectroscopy can provide nondestructive, qualitative analysis of protein-based binding media found in artworks. Fluorescence emissions from proteins in egg yolk and egg white are due to autofluorescent aromatic amino acids as well as other native and age-related fluorophores, but the potential of fluorescence spectroscopy for the differentiation between binding media is dependent on the choice of a suitable excitation wavelength and limited by problems in interpretation. However, a better understanding of emission spectra associated with LIF can be achieved following comparisons with total emission fluorescence spectra where a series of consecutive emission spectra are recorded over a specific range. Results using nanosecond UV laser sources for LIF of egg-based binding media are presented which are rationalised following comparisons with total emission spectra. Specifically, fluorescence is assigned to tryptophan and oxidation products of amino acids; in the case of egg yolk, fatty-acid polymerisation and age-related degradation products account for the formation of fluorophores.

Fluorescence spectroscopy for chromophore studies on bleached kraft pulps

Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 509-515 ◽  
Author(s):  
Sirje Liukko ◽  
Ville Tasapuro ◽  
Tiina Liitiä
Keyword(s):  
Fluorescence Spectroscopy ◽  
Fluorescence Spectra ◽  
Lignin Content ◽  
Excitation Wavelength ◽  
Kraft Pulps ◽  
Carbonyl Groups ◽  
Residual Lignin ◽  
Pulp Bleaching ◽  
Peroxide Bleaching ◽  
Brightness Reversion

Abstract Fluorescence techniques are highly sensitive and, since aromatic lignin is the most likely source of natural pulp fluorescence, they are suitable for detailed investigation of residual lignin in bleached pulps. Such investigations are important to our understanding of the bleachability and brightness reversion of pulps. In this study, the effect of bleaching on pulps was evaluated using fluorescence spectra of two softwood kraft pulps bleached in six elemental chlorine-free and totally chlorine-free sequences. Fluorescence spectra were recorded in each bleaching stage using four different instrument settings. In general, pulp fluorescence at excitation wavelengths of 270 and 350 nm increased as bleaching proceeded. Below a certain lignin content, however, pulp fluorescence measured at an excitation wavelength of 430 nm decreased with the residual lignin content. Carbonyl groups have a quenching effect on fluorescence, and the formation of carbonyl groups after oxygen and ozone delignification induced a decrease in pulp fluorescence. The increase in pulp fluorescence after peroxide bleaching stages was due to the removal of carbonyl groups. Reactions of chromophores during brightness reversion also had an effect on pulp fluorescence. These findings demonstrate that fluorescence spectroscopy provides an interesting tool for pulp bleaching studies.

scholarly journals THE EFFECTIVE OF DIFFERENT EXCITATION WAVELENGTHS ON THE IDENTIFICATION OF PLANT SPECIES BASED ON FLUORESCENCE LIDAR

2016 ◽  
Vol XLI-B1 ◽  
pp. 147-150
Author(s):  
Jian Yang ◽  
Wei Gong ◽  
Shuo Shi ◽  
Lin Du ◽  
Jia Sun ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Plant Species ◽  
Fluorescence Spectra ◽  
Principal Component ◽  
Laser Induced Fluorescence ◽  
Support Vector ◽  
Excitation Wavelength ◽  
Lidar System ◽  
Excitation Light

Laser-induced fluorescence (LIF) served as an active technology has been widely used in many field, and it is closely related to excitation wavelength (EW). The objective of this investigation is to discuss the performance of different EWs of LIF LiDAR in identifying plant species. In this study, the 355, 460 and 556 nm lasers were utilized to excite the leaf fluorescence and the fluorescence spectra were measured by using the LIF LiDAR system built in the laboratory. Subsequently, the principal component analysis (PCA) with the help of support vector machine (SVM) was utilized to analyse fluorescence spectra. For the three EWs, the overall identification rates of the six plant species were 80 %, 83.3 % and 90 %. Experimental results demonstrated that 556 nm excitation light source is superior to 355 and 460 nm for the classification of the plant species for the same genus in this study. Thus, an appropriate excitation wavelength should be considered when the LIF LiDAR was utilized in the field of remote sensing based on the LIF technology.

IDENTIFICATION OF PETROLEUM OILS BY FLUORESCENCE SPECTROSCOPY

1975 ◽  
Vol 1975 (1) ◽  
pp. 87-91 ◽  
Author(s):  
Uwe Frank
Keyword(s):  
Fluorescence Spectroscopy ◽  
Solvent Effects ◽  
Fluorescence Spectra ◽  
Three Dimensional ◽  
Excitation Wavelength ◽  
Dimensional System ◽  
Identification Methods ◽  
20 Nm ◽  
Three Dimensional System ◽  
Petroleum Oils

ABSTRACT A simple and rapid method for the identification of weathered petroleum oils (passive tagging) by fluorescence spectroscopy is described. The approach used takes advantage of the three-dimensional character of the oil fluorescence spectra. Oil identification methods of other investigators that use fluorescence spectroscopy are also reviewed within the context of the three-dimensional system. Our method involves excitation of the oils at 15 wavelengths, between 220–500 nanometers (nm), at 20-nm intervals. The emission monochromator is rapidly scanned at each excitation wavelength to obtain an emission spectrum. The maximum emission intensities are then plotted versus the excitation wavelengths to derive silhouette profiles. These are used as fingerprints for passive tagging petroleum oils. The influence of weathering, quenching, and solvent effects on our method are also examined.

scholarly journals Spectroscopic analysis of chia seeds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Monica Mburu ◽  
Olivier Paquet-Durand ◽  
Bernd Hitzmann ◽  
Viktoria Zettel
Keyword(s):  
Fluorescence Spectroscopy ◽  
Fluorescence Spectra ◽  
Nir Spectroscopy ◽  
South American ◽  
Prediction Errors ◽  
Nutritional Values ◽  
Standard Normal Variate ◽  
Spectral Evaluation ◽  
Standard Normal ◽  
First Time

AbstractChia seeds are becoming more and more popular in modern diets. In this contribution NIR and 2D-fluorescence spectroscopy were used to determine their nutritional values, mainly fat and protein content. 25 samples of chia seeds were analysed, whereof 9 samples were obtained from different regions in Kenya, 16 samples were purchased in stores in Germany and originated mostly from South America. For the purchased samples the nutritional information of the package was taken in addition to the values obtained for fat and protein, which were determined at the Hohenheim Core Facility. For the first time the NIR and fluorescence spectroscopy were used for the analysis of chia. For the spectral evaluation two different pre-processing methods were tested. Baseline correction with subsequent mean-centring lead to the best results for NIR spectra whereas SNV (standard normal variate transformation) was sufficient for the evaluation of fluorescence spectra. When combining NIR and fluorescence spectra, the fluorescence spectra were also multiplied with a factor to adjust the intensity levels. The best prediction results for the evaluation of the combined spectra were obtained for Kenyan samples with prediction errors below 0.2 g/100 g. For all other samples the absolute prediction error was 0.51 g/100 g for fat and 0.62 g/100 g for protein. It is possible to determine the amount of protein and fat of chia seeds by fluorescence and NIR spectroscopy. The combination of both methods is beneficial for the predictions. Chia seeds from Kenya had similar protein and lipid contents as South American seeds.

scholarly journals Low-temperature and low-pressure effective fluorescence lifetimes and spectra of gaseous anisole and toluene

2021 ◽  
Vol 127 (4) ◽  
Author(s):  
M. Beuting ◽  
T. Dreier ◽  
C. Schulz ◽  
T. Endres
Keyword(s):  
Fluorescence Spectra ◽  
Laser Induced Fluorescence ◽  
Analytical Determination ◽  
Fluorescence Signal ◽  
Fluorescence Lifetimes ◽  
Pressure Sensing ◽  
Applicable Range ◽  
Ladder Models ◽  
First Time

AbstractFluorescence spectra and lifetimes of anisole and toluene vapor in nitrogen have been measured at conditions below ambient (257–293 K and 100–2000 mbar) upon excitation with 266-nm laser light to expand the applicable range of anisole and toluene laser-induced fluorescence (LIF) for conditions below room temperature that occur in expanding flows and cases with strong evaporative cooling. Anisole fluorescence spectra broaden with decreasing pressure while fluorescence lifetimes decrease simultaneously. This is consistent with a more pronounced effect of internal vibrational redistribution on the overall fluorescence signal and can be explained by significantly reduced collision rates. In the case of toluene, the transition from photo-induced heating to photo-induced cooling was observed for the first time for 266 nm. The data confirm predictions of earlier work and is particularly important for the advancement of the available photo-physical (step-ladder) models: since those transitions mark points where the molecules are already thermalized after excitation (i.e., no vibrational relaxation occurs during deactivation), they are important support points for fitting empirical parameters and allow analytical determination of the ground state energy transferred to the excited state. The data enable temperature and/or pressure sensing, e.g., in accelerating cold flows using laser-induced fluorescence of both tracers.

The Determination of Fluorescent Whitening Agent VBL by Fluorescence Spectroscopy

2013 ◽  
Vol 401-403 ◽  
pp. 1135-1138
Author(s):  
Jia Yue Sun ◽  
Qiu Mei Di ◽  
Qi Guang Xu
Keyword(s):  
Fluorescence Spectroscopy ◽  
Fluorescence Intensity ◽  
Calibration Curve ◽  
Fluorescence Spectra ◽  
Excitation Wavelength ◽  
Fluorescent Whitening Agent ◽  
Average Percentage ◽  
Comprehensive Method ◽  
Whitening Agent

Comprehensive method for determining the fluorescent agents was studied through studying the fluorescence spectra of different concentration of VBL. The emission and excitation wavelength in the measurement was 275nm, and 434nm, respectively. When the concentrations of VBL are changing from 0 to 1.0 μg/mL, they have a linear relationship with the emitted fluorescence intensity. In this interval, the calibration curve is y= 1 6.713x+0.7879, showing strong correlation (correlation coefficient R2 is 0.9979). The average percentage of recovery is 89.9%, which meets the measuring requirements. The interaction between VBL and CTAB is preliminary studied.

scholarly journals THE EFFECTIVE OF DIFFERENT EXCITATION WAVELENGTHS ON THE IDENTIFICATION OF PLANT SPECIES BASED ON FLUORESCENCE LIDAR

2016 ◽  
Vol XLI-B1 ◽  
pp. 147-150 ◽  
Author(s):  
Jian Yang ◽  
Wei Gong ◽  
Shuo Shi ◽  
Lin Du ◽  
Jia Sun ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Plant Species ◽  
Fluorescence Spectra ◽  
Principal Component ◽  
Laser Induced Fluorescence ◽  
Support Vector ◽  
Excitation Wavelength ◽  
Lidar System ◽  
Excitation Light

Laser-induced fluorescence (LIF) served as an active technology has been widely used in many field, and it is closely related to excitation wavelength (EW). The objective of this investigation is to discuss the performance of different EWs of LIF LiDAR in identifying plant species. In this study, the 355, 460 and 556 nm lasers were utilized to excite the leaf fluorescence and the fluorescence spectra were measured by using the LIF LiDAR system built in the laboratory. Subsequently, the principal component analysis (PCA) with the help of support vector machine (SVM) was utilized to analyse fluorescence spectra. For the three EWs, the overall identification rates of the six plant species were 80 %, 83.3 % and 90 %. Experimental results demonstrated that 556 nm excitation light source is superior to 355 and 460 nm for the classification of the plant species for the same genus in this study. Thus, an appropriate excitation wavelength should be considered when the LIF LiDAR was utilized in the field of remote sensing based on the LIF technology.

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