scholarly journals A Laser-Based Method for the Detection of Honey Adulteration

2021 ◽  
Vol 11 (14) ◽  
pp. 6435
Author(s):  
Dimitrios Stefas ◽  
Nikolaos Gyftokostas ◽  
Panagiotis Kourelias ◽  
Eleni Nanou ◽  
Vasileios Kokkinos ◽  
...  
Keyword(s):  
Predictive Models ◽  
Machine Learning Algorithms ◽  
Spectral Lines ◽  
Laser Induced Breakdown Spectroscopy ◽  
Linear Discriminant ◽  
Breakdown Spectroscopy ◽  
Extremely Randomized Trees ◽  
Glucose Syrup ◽  
Laser Induced Breakdown ◽  
Sodium And Potassium

In the present work, laser-induced breakdown spectroscopy, aided by some machine learning algorithms (i.e., linear discriminant analysis (LDA) and extremely randomized trees (ERT)), is used for the detection of honey adulteration with glucose syrup. In addition, it is shown that instead of the entire LIBS spectrum, the spectral lines of inorganic ingredients of honey (i.e., calcium, sodium, and potassium) can be also used for the detection of adulteration providing efficient discrimination. The constructed predictive models attained high classification accuracies exceeding 90% correct classification.

scholarly journals Laser-Induced Breakdown Spectroscopy Assisted by Machine Learning for Plastics/Polymers Identification

Atoms ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 79 ◽  
Author(s):  
Dimitrios Stefas ◽  
Nikolaos Gyftokostas ◽  
Elli Bellou ◽  
Stelios Couris
Keyword(s):  
Machine Learning ◽  
Flame Retardants ◽  
Principal Component ◽  
Machine Learning Algorithms ◽  
Laser Induced Breakdown Spectroscopy ◽  
Linear Discriminant ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Algorithmic Approaches ◽  
Polymeric Samples

In the present work, Laser-Induced Breakdown Spectroscopy (LIBS) is used for the discrimination/identification of different plastic/polymeric samples having the same polymeric matrix but containing different additives (as e.g., fillers, flame retardants, etc.). For the classification of the different plastic samples, some machine learning algorithms were employed for the analysis of the LIBS spectroscopic data, such as the Principal Component Analysis (PCA) and the Linear Discriminant Analysis (LDA). The combination of LIBS technique with these machine learning algorithmic approaches, in particular the latter, provided excellent classification results, achieving identification accuracies as high as 100%. It seems that machine learning paves the way towards the application of LIBS technique for identification/discrimination issues of plastics and polymers and eventually of other classes of organic materials. Machine learning assisted LIBS can be a simple to use, efficient and powerful tool for sorting and recycling purposes.

Gold Nanoparticle-Enhanced Laser-Induced Breakdown Spectroscopy and Three-Dimensional Contour Imaging of an Aluminum Alloy

2020 ◽  
pp. 000370282097304
Author(s):  
Amal A. Khedr ◽  
Mahmoud A. Sliem ◽  
Mohamed Abdel-Harith
Keyword(s):  
Gold Nanoparticles ◽  
Aluminum Alloy ◽  
Three Dimensional ◽  
Plasma Temperature ◽  
Spectral Lines ◽  
Laser Induced Breakdown Spectroscopy ◽  
Al Alloy ◽  
Boltzmann Plot ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

In the present work, nanoparticle-enhanced laser-induced breakdown spectroscopy was used to analyze an aluminum alloy. Although LIBS has numerous advantages, it suffers from low sensitivity and low detection limits compared to other spectrochemical analytical methods. However, using gold nanoparticles helps to overcome such drawbacks and enhances the LIBS sensitivity in analyzing aluminum alloy in the current work. Aluminum was the major element in the analyzed samples (99.9%), while magnesium (Mg) was the minor element (0.1%). The spread of gold nanoparticles onto the Al alloy and using a laser with different pulse energies were exploited to enhance the Al alloy spectral lines. The results showed that Au NPs successfully improved the alloy spectral lines intensity by eight times, which could be useful for detecting many trace elements in higher matrix alloys. Under the assumption of local thermodynamic equilibrium, the Boltzmann plot was used to calculate the plasma temperature. Besides, the electron density was calculated using Mg and H lines at Mg(I) at 285.2 nm and Hα(I) at 656.2 nm, respectively. Three-dimensional contour mapping and color fill images contributed to understanding the behavior of the involved effects.

Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy Using Copper–Silver and Nickel–Carbon Nanocomposites on Aluminium

2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940022
Author(s):  
V. V. Kiris ◽  
A. V. Butsen ◽  
E. A. Ershov-Pavlov ◽  
M. I. Nedelko ◽  
A. A. Nevar
Keyword(s):  
Laser Ablation ◽  
Emission Intensity ◽  
Aluminum Foil ◽  
Spectral Lines ◽  
Laser Induced Breakdown Spectroscopy ◽  
Cu Nanoparticles ◽  
Laser Plume ◽  
Carbon Nanocomposites ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

Composite Ag–Cu and Ni–C nanoparticles were synthesized by laser ablation and spark discharge in liquid, respectively. An amplification of the signal during laser induced breakdown spectroscopy was observed after deposition of the nanoparticles on the surface of an aluminum foil. The emission intensity of the laser plume increased from 2 to 20 times depending on the spectral lines used for the measurements. The intensity growth was higher for Ag–Cu nanoparticles.

scholarly journals Classification of Copper Minerals by Handheld Laser-Induced Breakdown Spectroscopy and Nonnegative Tensor Factorisation

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5152
Author(s):  
Michał Wójcik ◽  
Pia Brinkmann ◽  
Rafał Zdunek ◽  
Daniel Riebe ◽  
Toralf Beitz ◽  
...  
Keyword(s):  
Handheld Devices ◽  
Laser Induced Breakdown Spectroscopy ◽  
Support Vector ◽  
Linear Discriminant ◽  
Mining Sites ◽  
Breakdown Spectroscopy ◽  
Tensor Methods ◽  
Classification Score ◽  
Laser Induced Breakdown ◽  
High Measurement

Laser-induced breakdown spectroscopy (LIBS) analysers are becoming increasingly common for material classification purposes. However, to achieve good classification accuracy, mostly noncompact units are used based on their stability and reproducibility. In addition, computational algorithms that require significant hardware resources are commonly applied. For performing measurement campaigns in hard-to-access environments, such as mining sites, there is a need for compact, portable, or even handheld devices capable of reaching high measurement accuracy. The optics and hardware of small (i.e., handheld) devices are limited by space and power consumption and require a compromise of the achievable spectral quality. As long as the size of such a device is a major constraint, the software is the primary field for improvement. In this study, we propose a novel combination of handheld LIBS with non-negative tensor factorisation to investigate its classification capabilities of copper minerals. The proposed approach is based on the extraction of source spectra for each mineral (with the use of tensor methods) and their labelling based on the percentage contribution within the dataset. These latent spectra are then used in a regression model for validation purposes. The application of such an approach leads to an increase in the classification score by approximately 5% compared to that obtained using commonly used classifiers such as support vector machines, linear discriminant analysis, and the k-nearest neighbours algorithm.

Characteristics of spectral lines with crater development during laser-induced breakdown spectroscopy

2016 ◽  
Vol 55 (26) ◽  
pp. 7422 ◽  
Author(s):  
Kuohu Li ◽  
Lianbo Guo ◽  
Xiangyou Li ◽  
Zhongqi Hao ◽  
Jiaming Li ◽  
...  
Keyword(s):  
Spectral Lines ◽  
Laser Induced Breakdown Spectroscopy ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

Investigations of calcium spectral lines in laser-induced breakdown spectroscopy

2017 ◽  
Author(s):  
Sim Yit Ching ◽  
Usman Tariq ◽  
Zuhaib Haider ◽  
Kashif Tufail ◽  
Salwanie Sabri ◽  
...  
Keyword(s):  
Spectral Lines ◽  
Laser Induced Breakdown Spectroscopy ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

scholarly journals Determination of Species Concentrations of Ti-6Al-4V Titanium Alloys using Calibration Free Laser Induced Breakdown Spectroscopy

2018 ◽  
Vol 3 (8) ◽  
pp. 50 ◽  
Author(s):  
Tagreed K. Hamad ◽  
Hussein Thamer Salloom
Keyword(s):  
Energy Levels ◽  
Surface Hardness ◽  
Plasma Temperature ◽  
Hardness Test ◽  
Spectral Lines ◽  
Laser Induced Breakdown Spectroscopy ◽  
Boltzmann Plot ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Calibration Free

In this study, Calibration-free Laser-induced breakdown spectroscopy (CF-LIBS) was applied to quantitatively analyze the elemental composition of Ti-6Al-4V titanium based alloy samples with no need for matrix-matched calibration procedure. Nd:YAG pulsed laser operating at a wavelength of 1064 nm was focused onto the sample to generate plasma. The spectrum of plasma was recorded using spectrophotometer then compared to NIST spectral lines to determine characteristic wavelengths, energy levels and other spectroscopic parameters. The values of plasma temperature obtained using Boltzmann plot for four examined samples ranged from 7439 to 6826 K while the electron density for each element was determined using Boltzmann-Saha equation. The concentration of Ti, Al, V and Fe has been determined and were within the samples nominal concentrations obtained from XRF analysis.  The calculated average relative errors of Ti, Al, V and Fe were 0.39%, 4.38%, 4.94 % and 8.2 %, respectively. Finally, there was a direct proportionality relation between the ratio of ionic to neutral emission lines of Ti for four samples and the surface hardness values measured mechanically using Vickers hardness test. The ratio at   had the best linear regression value (R2=0.95) which indicates the best correlation with surface hardness.

scholarly journals Investigation of compositional analysis and physical properties for Ni-Cr-Nb alloys using laser-induced breakdown spectroscopy

2021 ◽  
Vol 51 (3) ◽  
Author(s):  
Hussein Salloom ◽  
Tagreed Hamad
Keyword(s):  
Thermal Conductivity ◽  
Laser Energy ◽  
Plasma Temperature ◽  
Compositional Analysis ◽  
Spectral Lines ◽  
Laser Induced Breakdown Spectroscopy ◽  
Elemental Content ◽  
Empirical Formulas ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

In this work, laser-induced breakdown spectroscopy (LIBS) analysis is optimized for direct estimation of elemental composition, thermal conductivity and hardness for Ni-Cr-Nb alloys. These alloys were chosen with a variable elemental content of niobium and chromium. The influence of laser energy and shot numbers on measuring line intensity was investigated. Based on the ratio between two spectral lines, calibration curves were formed to estimate the element concentration and LIBS results were confirmed with related energy-dispersive X-ray spectroscopy (EDS) data. Hardness and thermal conductivity estimation using LIBS were done by measuring the ratio between two spectral lines, plasma excitation temperature and electron density for different samples. Semi-empirical formulas correlated hardness and thermal conductivity with plasma temperature were established.

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