scholarly journals Diamonds Certify Themselves: Multivariate Statistical Provenance Analysis

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 916
Author(s):  
Catherine E. McManus ◽  
Nancy J. McMillan ◽  
James Dowe ◽  
Julie Bell
Keyword(s):  
Working Conditions ◽  
Laser Induced Breakdown Spectroscopy ◽  
Provenance Analysis ◽  
Carbon Structure ◽  
Multivariate Statistical ◽  
Breakdown Spectroscopy ◽  
Kimberley Process ◽  
The World ◽  
Laser Induced Breakdown ◽  
Conflict Diamonds

The country or mine of origin is an important economic and societal issue inherent in the diamond industry. Consumers increasingly want to know the provenance of their diamonds to ensure their purchase does not support inhumane working conditions. Governments around the world reduce the flow of conflict diamonds via paper certificates through the Kimberley Process, a United Nations mandate. However, certificates can be subject to fraud and do not provide a failsafe solution to stopping the flow of illicit diamonds. A solution tied to the diamonds themselves that can withstand the cutting and manufacturing process is required. Here, we show that multivariate analysis of LIBS (laser-induced breakdown spectroscopy) diamond spectra predicts the mine of origin at greater than 95% accuracy, distinguishes between natural and synthetic stones, and distinguishes between synthetic stones manufactured in different laboratories by different methods. Two types of spectral features, elemental emission peaks and emission clusters from C-N and C-C molecules, are significant in the analysis, indicating that the provenance signal is contained in the carbon structure itself rather than in inclusions.

scholarly journals Laser-Induced Breakdown Spectroscopy for the Discrimination of Explosives Based on the ReliefF Algorithm and Support Vector Machines

2021 ◽  
Vol 9 ◽  
Author(s):  
Yu Zhao ◽  
Q. Q. Wang ◽  
Xutai Cui ◽  
Geer Teng ◽  
Kai Wei ◽  
...  
Keyword(s):  
Support Vector Machines ◽  
Classification Model ◽  
Laser Induced Breakdown Spectroscopy ◽  
Support Vector ◽  
Multivariate Statistical ◽  
Classification Rate ◽  
Breakdown Spectroscopy ◽  
Line Region ◽  
Vector Machines ◽  
Laser Induced Breakdown

Real-time explosive detectors must be developed to facilitate the rapid implementation of appropriate protective measures against terrorism. We report a simple yet efficient methodology to classify three explosives and three non-explosives by using laser-induced breakdown spectroscopy. However, the similarity existing among the spectral emissions collected from the explosives resulted in the difficulty of separating samples. We calculated the weights of lines by using the ReliefF algorithm and then selected six line regions that could be identified from the arrangement of weights to calculate the area of each line region. A multivariate statistical method involving support vector machines was followed for the construction of the classification model. Several models were constructed using full spectra, 13 lines, and 100 lines selected by the arrangement of weights and areas of the selected line regions. The highest correct classification rate of the model reached 100% by using the six line regions.

scholarly journals Sulfur Detection in Soil by Laser Induced Breakdown Spectroscopy Assisted by Multivariate Analysis

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 541
Author(s):  
Odhisea Gazeli ◽  
Dimitrios Stefas ◽  
Stelios Couris
Keyword(s):  
Multivariate Analysis ◽  
Vacuum Ultraviolet ◽  
Organic Soil ◽  
Spectral Lines ◽  
Laser Induced Breakdown Spectroscopy ◽  
Multivariate Statistical ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Potential Use

Laser-induced breakdown spectroscopy (LIBS) is used for the detection and determination of sulfur content in some organic soil samples. The most suitable sulfur spectral lines for such tasks were found to occur in the vacuum ultraviolet (VUV) spectral region and they were used for the construction of calibration curves. For the analysis, both univariate and multivariate statistical models were employed. The results obtained by the different analysis techniques are evaluated and compared. The present study demonstrates both the applicability and efficiency of LIBS for fast sulfur detection in soil matrices when aided by multivariate analysis methods improving the accuracy and extending the potential use of LIBS in such applications.

Synchronous Detection of Heavy Metal ions in Aqueous Solution by Gold Nanoparticles SurfaceEnhanced Laser-Induced Breakdown Spectroscopy

2021 ◽  
Author(s):  
Yaqian Yao ◽  
Fan He ◽  
Qingyu Lin ◽  
Yonghui Tian ◽  
Tianlong Zhang ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Environmental Problem ◽  
Laser Induced Breakdown Spectroscopy ◽  
Synchronous Detection ◽  
Breakdown Spectroscopy ◽  
The World ◽  
Laser Induced Breakdown ◽  
Insufficient Sensitivity

Heavy metal ion-induced water pollution has become a severe environmental problem in the world. Although providing a powerful technique for multi-element detection, laser-induced breakdown spectroscopy (LIBS) suffers from insufficient sensitivity...

Nanosecond laser-induced breakdown assisted by femtosecond laser pre-ionization in air: the effect on spatial resolution and continuous radiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20701
Author(s):  
Bo Li ◽  
Xiaofeng Li ◽  
Zhifeng Zhu ◽  
Qiang Gao
Keyword(s):  
Femtosecond Laser ◽  
Spatial Resolution ◽  
Laser Induced Breakdown Spectroscopy ◽  
Nanosecond Laser ◽  
Breakdown Threshold ◽  
Powerful Technique ◽  
Breakdown Spectroscopy ◽  
Continuous Radiation ◽  
Laser Induced Breakdown

Laser-induced breakdown spectroscopy (LIBS) is a powerful technique for quantitative diagnostics of gases. The spatial resolution of LIBS, however, is limited by the volume of plasma. Here femtosecond-nanosecond dual-pulsed LIBS was demonstrated. Using this method, the breakdown threshold was reduced by 80%, and decay of continuous radiation was shortened. In addition, the volume of the plasma was shrunk by 85% and hence, the spatial resolution of LIBS was significantly improved.

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