scholarly journals Integrated Laser Sensor (ILS) for Remote Surface Analysis: Application for Detecting Explosives in Fingerprints

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4269 ◽  
Author(s):  
Lazic ◽  
Palucci ◽  
De Dominicis ◽  
Nuvoli ◽  
Pistilli ◽  
...  
Keyword(s):  
Target Area ◽  
Laser Sensor ◽  
Spectroscopic Techniques ◽  
Laser Scattering ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Analysis Application ◽  
Self Powered ◽  
Lif Spectroscopy ◽  
Working Distance

Here, we describe an innovative Integrated Laser Sensor (ILS) that combines four spectroscopic techniques and two vision systems into a unique, transportable device. The instrument performs Raman and Laser-Induced Fluorescence (LIF) spectroscopy excited at 355 nm and Laser-Induced Breakdown Spectroscopy (LIBS) excited at 1064 nm, and it also detects Laser Scattering (LS) from the target under illumination at 650 nm. The combination of these techniques supplies information about: material change from one scanning point to another, the presence of surface contaminants, and the molecular and elemental composition of top target layers. Switching between the spectroscopic techniques and the laser wavelengths is fully automatic. The instrument is equipped with an autofocus, and it performs scanning with a chosen grid density over an interactively-selected target area. Alternative to the spectroscopic measurements, it is possible to switch the instrument to a high magnification target viewing. The working distances tested until now are between 8.5 and 30 m. The instrument is self-powered and remotely controlled via wireless communication. The ILS has been fully developed at ENEA for security applications, and it was successfully tested in two outdoor campaigns where an automatic recognition of areas containing explosives in traces had been implemented. The strategies for the identification of nitro-compounds placed on various substrates as fingerprints and the results obtained at a working distance of 10 m are discussed in the following.

scholarly journals Classification of Greek Olive Oils from Different Regions by Machine Learning-Aided Laser-Induced Breakdown Spectroscopy and Absorption Spectroscopy

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1241
Author(s):  
Nikolaos Gyftokostas ◽  
Eleni Nanou ◽  
Dimitrios Stefas ◽  
Vasileios Kokkinos ◽  
Christos Bouras ◽  
...  
Keyword(s):  
Machine Learning ◽  
Olive Oil ◽  
Absorption Spectra ◽  
Absorption Spectroscopy ◽  
Laser Induced Breakdown Spectroscopy ◽  
Spectroscopic Techniques ◽  
Breakdown Spectroscopy ◽  
Olive Oils ◽  
Laser Induced Breakdown

In the present work, the emission and the absorption spectra of numerous Greek olive oil samples and mixtures of them, obtained by two spectroscopic techniques, namely Laser-Induced Breakdown Spectroscopy (LIBS) and Absorption Spectroscopy, and aided by machine learning algorithms, were employed for the discrimination/classification of olive oils regarding their geographical origin. Both emission and absorption spectra were initially preprocessed by means of Principal Component Analysis (PCA) and were subsequently used for the construction of predictive models, employing Linear Discriminant Analysis (LDA) and Support Vector Machines (SVM). All data analysis methodologies were validated by both “k-fold” cross-validation and external validation methods. In all cases, very high classification accuracies were found, up to 100%. The present results demonstrate the advantages of machine learning implementation for improving the capabilities of these spectroscopic techniques as tools for efficient olive oil quality monitoring and control.

scholarly journals Portable Spectroscopy

2018 ◽  
Vol 72 (12) ◽  
pp. 1701-1751 ◽  
Author(s):  
Richard A. Crocombe
Keyword(s):  
Near Infrared ◽  
Low Cost ◽  
Medical Diagnostics ◽  
Spectroscopic Techniques ◽  
The Public ◽  
Qualitative And Quantitative ◽  
Breakdown Spectroscopy ◽  
Crowdsourced Data ◽  
Laser Induced Breakdown ◽  
Consumer Devices

Until very recently, handheld spectrometers were the domain of major analytical and security instrument companies, with turnkey analyzers using spectroscopic techniques from X-ray fluorescence (XRF) for elemental analysis (metals), to Raman, mid-infrared, and near-infrared (NIR) for molecular analysis (mostly organics). However, the past few years have seen rapid changes in this landscape with the introduction of handheld laser-induced breakdown spectroscopy (LIBS), smartphone spectroscopy focusing on medical diagnostics for low-resource areas, commercial engines that a variety of companies can build up into products, hyphenated or dual technology instruments, low-cost visible-shortwave NIR instruments selling directly to the public, and, most recently, portable hyperspectral imaging instruments. Successful handheld instruments are designed to give answers to non-scientist operators; therefore, their developers have put extensive resources into reliable identification algorithms, spectroscopic libraries or databases, and qualitative and quantitative calibrations. As spectroscopic instruments become smaller and lower cost, “engines” have emerged, leading to the possibility of being incorporated in consumer devices and smart appliances, part of the Internet of Things (IOT). This review outlines the technologies used in portable spectroscopy, discusses their applications, both qualitative and quantitative, and how instrument developers and vendors have approached giving actionable answers to non-scientists. It outlines concerns on crowdsourced data, especially for heterogeneous samples, and finally looks towards the future in areas like IOT, emerging technologies for instruments, and portable hyphenated and hyperspectral instruments.

Laser focusing geometry effects on laser-induced plasma and laser-induced breakdown spectroscopy in bulk water

2019 ◽  
Vol 34 (1) ◽  
pp. 118-126 ◽  
Author(s):  
Ye Tian ◽  
Lintao Wang ◽  
Boyang Xue ◽  
Qian Chen ◽  
Ying Li
Keyword(s):  
Bulk Water ◽  
Fast Imaging ◽  
Laser Induced Breakdown Spectroscopy ◽  
Spectroscopic Techniques ◽  
Laser Induced Plasma ◽  
Breakdown Spectroscopy ◽  
Laser Focusing ◽  
Laser Induced Breakdown ◽  
Geometry Effects

The influences of laser focusing geometry on laser-induced plasma and laser-induced breakdown spectroscopy (LIBS) in bulk water are investigated by using fast imaging and spectroscopic techniques.

scholarly journals Elemental Profiling of Surface Water around Dhaka City by Laser Induced Breakdown Spectroscopy

1970 ◽  
Vol 33 (2) ◽  
pp. 209-218 ◽  
Author(s):  
MF Ahmed ◽  
KM Abedin ◽  
ME Sadat ◽  
AI Talukder ◽  
M Wahadoszamen ◽  
...  
Keyword(s):  
Surface Water ◽  
Laser Induced Breakdown Spectroscopy ◽  
Spectroscopic Techniques ◽  
Human Beings ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
High Concentrations ◽  
Elemental Profiling ◽  
Academy Of Sciences ◽  
The City

Using the technique of Laser Induced Breakdown Spectroscopy (LIBS), which uses a pulsed laser to create plasma and advanced spectroscopic techniques, we analyzed the contents of surface water (river water) around the city of Dhaka. Several elements such as Li, C, Na, Mg, Al, K, Ca, Ti, Mn, Fe, Sr were identified in the water samples collected in addition to Cr, which was found at two locations at different concentrations. Chromium is a toxic element, and its presence at high concentrations is hazardous for human beings as well as the environment. Its presence in water is suspected due to the effluent discharge from the nearby tanning industries. Semi-quantitative analysis of the chromium present was performed. To our knowledge, this is the first example of the application of the LIBS technique in water analysis in Bangladesh. DOI: 10.3329/jbas.v33i2.4104 Journal of Bangladesh Academy of Sciences, Vol. 33, No. 2, 209-218, 2009

Rapid and Sensitive Analysis of Trace Leads in Medicinal Herbs Using Laser-Induced Breakdown Spectroscopy–Laser-Induced Fluorescence (LIBS-LIF)

2019 ◽  
pp. 000370281985774 ◽  
Author(s):  
Yinhua Jiang ◽  
Juan Kang ◽  
Yarui Wang ◽  
Yuqi Chen ◽  
Runhua Li
Keyword(s):  
Calibration Curve ◽  
Laser Induced Fluorescence ◽  
Medicinal Herbs ◽  
Laser Induced Breakdown Spectroscopy ◽  
Analytical Sensitivity ◽  
Linear Calibration ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Lif Spectroscopy ◽  
Spectroscopy Laser

Toxic metals in medicinal herbs are potentially harmful for people taking herbal medicines. In this work, laser-induced breakdown spectroscopy–laser-induced fluorescence (LIBS-LIF) spectroscopy was first applied to carry out rapid and sensitive trace lead analysis in medicinal herb samples. To overcome the problem of diversity on the sample size, shape, and density for different samples, original samples were pulverized to powder and then pressed into pellets for spectral analysis. A series of standard samples were self-made for building a calibration curve. As an exemplary study, lead in Rheum officinale was analyzed with LIBS-LIF spectroscopy with significantly improved analytical sensitivity. The R2 of the build linear calibration curve was 0.996 and the detection limit of lead in R. officinale was determined to be 0.13 ppm. The enhancement factor on the signal-to-background ratio was >100 under low lead concentrations if compared with LIBS analysis. The lead concentrations in several original R. officinale samples were quantitatively determined. This work demonstrated that LIBS-LIF can be successfully applied to carry out rapid, sensitive, and quantitative trace lead analysis for medicinal herbs.

scholarly journals Recent Developments in Spectroscopic Techniques for the Detection of Explosives

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1364 ◽  
Author(s):  
Wei Zhang ◽  
Yue Tang ◽  
Anran Shi ◽  
Lirong Bao ◽  
Yun Shen ◽  
...  
Keyword(s):  
Ion Mobility ◽  
Thz Spectroscopy ◽  
Spectroscopic Techniques ◽  
Trace Detection ◽  
Detection Techniques ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Recent Developments ◽  
Critical Problems ◽  
Detection Of Explosives

Trace detection of explosives has been an ongoing challenge for decades and has become one of several critical problems in defense science; public safety; and global counter-terrorism. As a result, there is a growing interest in employing a wide variety of approaches to detect trace explosive residues. Spectroscopy-based techniques play an irreplaceable role for the detection of energetic substances due to the advantages of rapid, automatic, and non-contact. The present work provides a comprehensive review of the advances made over the past few years in the fields of the applications of terahertz (THz) spectroscopy; laser-induced breakdown spectroscopy (LIBS), Raman spectroscopy; and ion mobility spectrometry (IMS) for trace explosives detection. Furthermore, the advantages and limitations of various spectroscopy-based detection techniques are summarized. Finally, the future development for the detection of explosives is discussed.

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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