Quartz Enhanced Photoacoustic Spectroscopy for Detection of Improvised Explosive Devices and Precursors

Viola, Roberto; Liberatore, Nicola; Luciani, Domenico; Mengali, Sandro

doi:10.1155/2016/5757361

Cited by 9 publications

(10 citation statements)

References 20 publications

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“…Shown in Figure 5-20 is an example of a compact system designed by Viola et. al [31] that was able to maintain low limits of detection in the range of ppb. In FY18, a manifold was automated to perform the calibrations using LabView software from National Instruments TM .…”

Section: Fy18 Summarymentioning

confidence: 99%

Hanford Double Shell Waste Tank Corrosion Studies (Final Report FY2019)

Fuentes

Shukla

Crossland

et al. 2020

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VCIs formulations were added during mid-course of experiments, i.e., after coupons have experienced corrosion in the untreated GW simulant. Three tests were conducted using VCI-A and VCI-B. The first two tests were conducted using 100% recommended dosages of VCI-A and VCI-B. The third test was conducted at 10% of the recommended dosage of VCI-B. Following conclusions are made from the experimental data and results:  The corrosion rate data indicated that 10% of the recommended dosage is insufficient in mitigating corrosion. This observation is consistent with a prior study which also concluded that VCIs' effectiveness vanishes at 10% of the recommended dosages for the aboveground tank bottom underside application.  The data also showed that 100% recommended dosages of VCI-A and VCI-B mitigated pitting corrosion of weathered coupons. Specifically, VCI-A mitigated pitting corrosion in immersed, Level 2, and Level 3 coupons, whereas VCI-B mitigated pitting corrosion in immersed, Level 1, and Level 3 coupons. Statistical significance of corrosion rate decrease in Level 1 coupons for 100% recommended dosage of VCI-A and Level 2 coupons for 100% recommended dosage of VCI-B could not be established; this may be due to choice of coupons' surface orientation being vertical during the tests, leading to limited and uneven weathering during groundwater only and groundwater plus VCI exposures. 3. Long term OCP Drift Tests OCPs of carbon steel were measured in three simulants from the new limits testing. Two sets of coupons, with three coupons in each set, were fabricated with differing surface conditions. The coupons' surface conditions included a 600-grit polished surface, and a surface with mill-scale plus corrosion products from legacy carbon steel (rail car steel AAR TC-128). Two coupons, one coupon from each set, were placed in each chemistry, and OCPs of the coupons were monitored for five months. OCPs of the coupons with polished surfaces evolved in the anodic direction with respect to the initial values, whereas OCPs of two of the three coupons with mill-scale plus corrosion products evolved in cathodic direction with respect to the initial values. Terminal OCP of one mill-scale plus corrosion products coupon was about 100 mV anodic with respect to the initial value. CPP data of the polished coupons before OCP evolutions showed mixed responses, i.e., a clear delineation between pitting and no-pitting cannot be made, and CPP data after OCP evolutions remained mixed (category 3), indicating that change in OCP values did not affect the CPP responses. Following exposures of the coupons during OCP evolutions, CPP data for the mill-scale plus corrosion products coupons in the three simulants showed negative hysteresis (category 1), which is a sign of no-pitting. The OCP and CPP data indicate that simulant chemistry and surface condition affect extent and direction of OCP evolution, however, OCP evolution does not affect the pitting susceptibility. Electrochemical Impedance Spectroscopy (EIS) spectra of the polished coupon...

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Section: Fy18 Summarymentioning

confidence: 99%

Hanford Double Shell Waste Tank Corrosion Studies (Final Report FY2019)

Fuentes

Shukla

Crossland

et al. 2020

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“…Shown in Figure 3-2 is an example of a compact system designed by Viola et. al [12] that was able to maintain low limits of detection in the range of ppb. Details on the humidity, calibration, and vapor cell tests will be presented in Section 5.4…”

Section: Task 4: Qepas Studiesmentioning

confidence: 99%

“… Utilizing corroded samples, perform the tests in simulated waste solutions over a broad range of pH (e.g., [10][11][12][13][14] and pitting factor (i.e., less than 1 to greater than 2). Ideally, the tests would evaluate potential pitting susceptibility (i.e., the red region) as well as the region where the risk of pitting susceptibility is less (i.e., the green region).…”

Section: Anodic Driftmentioning

confidence: 99%

Hanford Double Shell Waste Tank Corrosion Studies (Final Report FY2018)

Fuentes

Shukla

Peters

et al. 2019

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“…The QEPAS sensor, however, is much more compact, robust and cheap than an analogous IRAS sensor of similar sensitivity, which is based on multi-pass cells and cooled cadmium-mercury-telluride (CMT) detectors. Moreover, the QEPAS technique enables the miniaturization of the interrogation cell [19], and is therefore particularly suitable for coupling with FAST-GC (which is itself characterized by miniaturized volumes). For our sensor we developed a novel miniaturized interrogation cell sized 30 mm × 30 mm × 25 mm, as shown in Figure 5b.…”

Section: Sensor Descriptionmentioning

confidence: 99%

A MEMS-Enabled Deployable Trace Chemical Sensor Based on Fast Gas-Chromatography and Quartz Enhanced Photoacousic Spectoscopy

Zampolli

Mengali

Liberatore

et al. 2019

Sensors

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This paper reports on a portable selective chemical sensor for hazardous vapors at trace levels, which combines a two-stage purge and trap vapor pre-concentration system, a Micro-Electro-Mechanical-System (MEMS) based fast gas-chromatographic (FAST-GC) separation column and a miniaturized quartz-enhanced photoacoustic spectroscopy (QEPAS) detector. The integrated sensing system provides two-dimensional selectivity combining GC retention time and QEPAS spectral information, and was specifically designed to be rugged and suitable to be deployed on unmanned robotic ground vehicles. This is the first demonstration of a miniaturized QEPAS device used as spectroscopic detector downstream of a FAST-GC separation column, enabling real-world analyses in dirty environments with response time of a few minutes. The main modules of the GC/QEPAS sensor device will be described in detail together with the system integration, and successful test results will be reported and discussed.

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Quartz Enhanced Photoacoustic Spectroscopy for Detection of Improvised Explosive Devices and Precursors

Cited by 9 publications

References 20 publications

Hanford Double Shell Waste Tank Corrosion Studies (Final Report FY2019)

Hanford Double Shell Waste Tank Corrosion Studies (Final Report FY2019)

Hanford Double Shell Waste Tank Corrosion Studies (Final Report FY2018)

A MEMS-Enabled Deployable Trace Chemical Sensor Based on Fast Gas-Chromatography and Quartz Enhanced Photoacousic Spectoscopy

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