Laser based in-situ and standoff detection of chemical warfare agents and explosives

2009 ◽  
Author(s):  
C. Kumar N. Patel
Keyword(s):  
Chemical Warfare Agents ◽  
Chemical Warfare ◽  
Standoff Detection ◽  
Warfare Agents

Raman Spectroscopic Detection for Simulants of Chemical Warfare Agents Using a Spatial Heterodyne Spectrometer

2017 ◽  
Vol 72 (1) ◽  
pp. 151-158 ◽  
Author(s):  
Guangxiao Hu ◽  
Wei Xiong ◽  
Haiyan Luo ◽  
Hailiang Shi ◽  
Zhiwei Li ◽  
...  
Keyword(s):  
Chemical Warfare Agents ◽  
Diethyl Malonate ◽  
Chemical Characteristic ◽  
Chemical Warfare ◽  
High Spectral Resolution ◽  
Large Field ◽  
Raman Spectroscopic ◽  
Standoff Detection ◽  
Warfare Agents

Raman spectroscopic detection is one of the suitable methods for the detection of chemical warfare agents (CWAs) and simulants. Since the 1980s, many researchers have been dedicated to the research of chemical characteristic of CWAs and simulants and instrumental improvement for their analysis and detection. The spatial heterodyne Raman spectrometer (SHRS) is a new developing instrument for Raman detection that appeared in 2011. It is already well-known that SHRS has the characteristics of high spectral resolution, a large field-of-view, and high throughput. Thus, it is inherently suitable for the analysis and detection of these toxic chemicals and simulants. The in situ and standoff detection of some typical simulants of CWAs, such as dimethyl methylphosphonate (DMMP), diisopropyl methylphosphonate (DIMP), triethylphosphate (TEP), diethyl malonate (DEM), methyl salicylate (MES), 2-chloroethyl ethyl sulfide (CEES), and malathion, were tried. The achieved results show that SHRS does have the ability of in situ analysis or standoff detection for simulants of CWAs. When the laser power was set to as low as 26 mW, the SHRS still has a signal-to-noise ratio higher than 5 in in situ detection. The standoff Raman spectra detection of CWAs simulants was realized at a distance of 11 m. The potential feasibility of standoff detection of SHRS for CWAs simulants has been proved.

A two-pulse, pump-probe method for short-range, remote standoff detection of chemical warfare agents

2011 ◽  
Author(s):  
Scott E. Bisson ◽  
Jeffrey M. Headrick ◽  
Thomas A. Reichardt ◽  
Roger L. Farrow ◽  
Thomas J. Kulp
Keyword(s):  
Short Range ◽  
Chemical Warfare Agents ◽  
Chemical Warfare ◽  
Probe Method ◽  
Pump Probe ◽  
Standoff Detection ◽  
Warfare Agents ◽  
Pulse Pump

scholarly journals In-situ detoxification of schedule-I chemical warfare agents utilizing Zr(OH)4@W-ACF functional material for the development of next generation NBC protective gears

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Imran ◽  
Virendra V. Singh ◽  
Prabhat Garg ◽  
Avik Mazumder ◽  
Lokesh K. Pandey ◽  
...  
Keyword(s):  
Surface Area ◽  
Degradation Products ◽  
Wide Spectrum ◽  
Chemical Warfare Agents ◽  
Chemical Warfare ◽  
Bet Surface Area ◽  
High Dispersion ◽  
Reactive Material ◽  
Warfare Agents

AbstractChemical warfare agents (CWAs) have become a pivotal concern for the global community and spurred a wide spectrum of research for the development of new generation protective materials. Herein, a highly effective self-detoxifying filter consisting of in-situ immobilized Zirconium hydroxide [Zr(OH)4] over woven activated carbon fabric [Zr(OH)4@W-ACF] is presented for the removal of CWAs. It was prepared to harness the synergistic effect of high surface area of W-ACF, leads to high dispersion of CWAs and high phosphilicity and reactivity of [Zr(OH)4]. The synthesized materials were characterized by ATR-FTIR, EDX, SEM, TEM, XPS, TGA, and BET surface area analyzer. The kinetics of  in-situ degradation of CWAs over Zr(OH)4@W-ACF were studied and found to be following the first-order reaction kinetics. The rate constant was found to be 0.244 min−1 and 2.31 × 10−2 min−1 for sarin and soman, respectively over Zr(OH)4@W-ACF. The potential practical applicability of this work was established by fabricating Zr(OH)4@W-ACF as reactive adsorbent layer for protective suit, and found to be meeting the specified criteria in terms of air permeability, tearing strength and nerve agent permeation as per TOP-08-2-501A:2013 and IS-17380:2020. The degradation products of CWAs were analyzed with NMR and GC–MS. The combined properties of dual functional textile with reactive material are expected to open up new exciting avenues in the field of CWAs protective clothing and thus find diverse application in defence and environmental sector.

scholarly journals Denoising Autoencoder based Noise Reduction Technique for Raman Spectrometers for Standoff Detection of Chemical Warfare Agents

2021 ◽  
Vol 24 (4) ◽  
pp. 374-381
Author(s):  
Chang Sik Lee ◽  
Hyeong-Geun Yu ◽  
Jae-Hyeon Park ◽  
Whimin Kim ◽  
Dong-Jo Park ◽  
...  
Keyword(s):  
Raman Spectrum ◽  
Noise Reduction ◽  
Random Noise ◽  
Chemical Warfare Agents ◽  
Chemical Warfare ◽  
Molecular Structures ◽  
Spectral Features ◽  
Denoising Autoencoder ◽  
Standoff Detection ◽  
Warfare Agents

Raman spectrometers are studied and developed for the military purposes because of their nondestructive inspection capability to capture unique spectral features induced by molecular structures of colorless and odorless chemical warfare agents(CWAs) in any phase. Raman spectrometers often suffer from random noise caused by their detector inherent noise, background signal, etc. Thus, reducing the random noise in a measured Raman spectrum can help detection algorithms to find spectral features of CWAs and effectively detect them. In this paper, we propose a denoising autoencoder for Raman spectra with a loss function for sample efficient learning using noisy dataset. We conduct experiments to compare its effect on the measured spectra and detection performance with several existing noise reduction algorithms. The experimental results show that the denoising autoencoder is the most effective noise reduction algorithm among existing noise reduction algorithms for Raman spectrum based standoff detection of CWAs.

Rapid, In-Situ Detection of Chemical Warfare Agent Simulants and Hydrolysis Products in Bulk Soils by Low-Cost 3D-Printed Cone Spray Ionization Mass Spectrometry

The Analyst ◽  
2021 ◽  
Author(s):  
Hilary M. Brown ◽  
Trevor J. McDaniel ◽  
Karan R. Doppalapudi ◽  
Christopher C. Mulligan ◽  
Patrick Fedick
Keyword(s):  
Low Cost ◽  
Chemical Warfare Agents ◽  
Chemical Warfare Agent ◽  
Chemical Warfare ◽  
Ionization Mass ◽  
Chemical Weapons Convention ◽  
Warfare Agents ◽  
3D Printed ◽  
In Situ Detection

Chemical warfare agents (CWAs) are toxic chemicals that have been used as disabling or lethal weapons in war, terrorist attacks, and assassinations. The Chemical Weapons Convention (CWC) has prohibited the...

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