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Basner M.,University of Pennsylvania | Rubinstein J.,Transportation Security Laboratory
Journal of Occupational and Environmental Medicine | Year: 2011

Objective: To evaluate the ability of a 3-minute Psychomotor Vigilance Test (PVT) to predict fatigue-related performance decrements on a simulated luggage-screening task (SLST). Methods: Thirty-six healthy nonprofessional subjects (mean age = 30.8 years, 20 women) participated in a 4-day laboratory protocol including a 34-hour period of total sleep deprivation with PVT and SLST testing every 2 hours. Results: Eleven and 20 lapses (355-ms threshold) on the PVT optimally divided SLST performance into high-, medium-, and low-performance bouts with significantly decreasing threat detection performance A′. Assignment to the different SLST performance groups replicated homeostatic and circadian patterns during total sleep deprivation. Conclusions: The 3-minute PVT was able to predict performance on a simulated luggage-screening task. Fitness-for-duty feasibility should now be tested in professional screeners and operational environments. Copyright © 2011 by American College of Occupational and Environmental Medicine.

Tomlinson-Phillips J.,Transportation Security Laboratory | Wooten A.,Battelle | Kozole J.,Transportation Security Laboratory | Kozole J.,DuPont Company | And 3 more authors.
Talanta | Year: 2014

Identification of the fragment ion species associated with the ion reaction mechanism of triacetone triperoxide (TATP), a homemade peroxide-based explosive, is presented. Ion mobility spectrometry (IMS) has proven to be a key analytical technique in the detection of trace explosive material. Unfortunately, IMS alone does not provide chemical identification of the ions detected; therefore, it is unknown what ion species are actually formed and separated by the IMS. In IMS, ions are primarily characterized by their drift time, which is dependent on the ions mass and molecular cross-section; thus, IMS as a standalone technique does not provide structural signatures, which is in sharp contrast to the chemical and molecular information that is generally obtained from other customary analytical techniques, such as NMR, Raman and IR spectroscopy and mass spectrometry. To help study the ion chemistry that gives rise to the peaks observed in IMS, the hardware of two different commercial IMS instruments has been directly coupled to triple quadrupole (QQQ) mass spectrometers, in order to ascertain each ions corresponding mass/charge (m/z) ratios with different dopants at two temperatures. Isotope labeling was then used to help identify and confirm the molecular identity of the explosive fragment and adduct ions of TATP. The m/z values and isotope labeling experiments were used to help propose probable molecular formulas for the ion fragments. In this report, the fragment and adduct ions m/z 58 and 240 of TATP have been confirmed to be [C3H6NHH]+ and [TATPNH4]+, respectively; while the fragment ions m/z 73 and 89 of TATP are identified as having the molecular formulas [C 4H9NH2]+ and [C4H 9O2]+, respectively. It is anticipated that the work in this area will not only help to facilitate improvements in mobility-based detection (IMS and MS), but also aid in the development and optimization of MS-based detection algorithms for TATP. © Published by Elsevier B.V.

Kozole J.,Transportation Security Laboratory | Kozole J.,Nova Research Inc. | Tomlinson-Phillips J.,Transportation Security Laboratory | Stairs J.R.,Transportation Security Laboratory | And 7 more authors.
Talanta | Year: 2012

A commercial-off-the-shelf (COTS) ion trap mobility spectrometry (ITMS) based explosive trace detector (ETD) has been interfaced to a triple quadrupole mass spectrometer (MS/MS) for the purpose of characterizing the gas phase ion chemistry intrinsic to the ITMS instrument. The overall objective of the research is to develop a fundamental understanding of the gas phase ionization processes in the ITMS based ETD to facilitate the advancement of its operational effectiveness as well as guide the development of next generation ETDs. Product ion masses, daughter ion masses, and reduced mobility values measured by the ITMS/MS/MS configuration for a suite of nitro, nitrate, and peroxide containing explosives are reported. Molecular formulas, molecular structures, and ionization pathways for the various product ions are inferred using the mass and mobility data in conjunction with density functional theory. The predominant product ions are identified as follows: [TNT-H] - for trinitrotoluene (TNT), [RDXCl] - for cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX), [NO 3] - for ethylene glycol dinitrate (EGDN), [NGNO 3] - for nitroglycerine (NG), [PETNNO 3] - for pentaerythritol tetranitrate (PETN), [HNO 3NO 3] - for ammonium nitrate (NH 4NO 3), [HMTD-NC 3H 6O 3HCl] - for hexamethylene triperoxide diamine (HMTD), and [(CH 3) 2CNH 2] for triacetone triperoxide (TATP). The predominant ionization pathways for the formation of the various product ions are determined to include proton abstraction, ion-molecule attachment, autoionization, first-order and multi-order thermolysis, and nucleophilic substitution. The ion trapping scheme in the reaction region of the ITMS instrument is shown to increase predominant ion intensities relative to the secondary ion intensities when compared to non-ion trap operation. © 2012 Elsevier B.V. All rights reserved.

Orton S.L.,University of Missouri | Chiarito V.P.,U.S. Army | Minor J.K.,U.S. Army | Coleman T.G.,Transportation Security Laboratory
Journal of Structural Engineering (United States) | Year: 2014

Strengthening reinforced concrete slab or wall structural elements with carbon fiber-reinforced polymer (CFRP) can improve their blast resistance. However, close-in blasts (blasts with a scaled range of less than 0.4 m/kg1/3) may undermine the effectiveness of the CFRP strengthening. This paper presents an experimental testing program on CFRP-strengthened reinforced concrete slab specimens that utilized fiber anchors. Two CFRP mitigation designs were tested under blast loads with a scaled range of 0.4 and 0.6 m/kg1/3. Tests on unmitigated reinforced concrete slab specimens provided baseline comparisons. The experimental results showed that the use of CFRP strengthening improved the blast resistance of reinforced concrete slab specimens. For a larger scaled range, 0.6 m/kg1/3, the CFRP successfully prevented flying debris and reduced the overall deflections of the slab specimens. However, for the closer scaled range, 0.4 m/kg1/3, the high shock blast pressures shattered the concrete through the thickness of the slab specimen and tore through the back-face CFRP. However, back-face velocity and overall deflections were reduced by about 75% compared to the baseline test slab specimen. © 2013 American Society of Civil Engineers.

Kozole J.,Transportation Security Laboratory | Kozole J.,Nova Research Inc. | Stairs J.R.,Transportation Security Laboratory | Cho I.,Transportation Security Laboratory | And 7 more authors.
Analytical Chemistry | Year: 2011

Hardware from a commercial-off-the-shelf (COTS) ion mobility spectrometry (IMS) based explosive trace detector (ETD) has been interfaced to an AB/SCIEX API 2000 triple quadrupole mass spectrometer. To interface the COTS IMS based ETD to the API 2000, the faraday plate of the IMS instrument and the curtain plate of the mass spectrometer were removed from their respective systems and replaced by a custom faraday plate, which was fabricated with a hole for passing the ion beam to the mass spectrometer, and a custom interface flange, which was designed to attach the IMS instrument onto the mass spectrometer. Additionally, the mass spectrometer was modified to increase the electric field strength and decrease the pressure in the differentially pumped interface, causing a decrease in the effect of collisional focusing and permitting a mobility spectrum to be measured using the mass spectrometer. The utility of the COTS-ETD/API 2000 configuration for the characterization of the gas phase ion chemistry of COTS-ETD equipment was established by obtaining mass and tandem mass spectra in the continuous ion flow and selected mobility monitoring operating modes and by obtaining mass-selected ion mobility spectra for the explosive standard 2,4,6 trinitrotoluene (TNT). This analysis confirmed that the product ion for TNT is [TNT - H] -, the predominant collision-induced dissociation pathway for [TNT- H] - is the loss of NO and NO 2, and the reduced mobility value for [TNT - H] - is 1.54 cm 2V -1 s -1. Moreover, this analysis was attained for sample amounts of 1 ng and with a resolving power of 37. The objective of the research is to advance the operational effectiveness of COTS IMS based ETD equipment by developing a platform that can facilitate the understanding of the ion chemistry intrinsic to the equipment. © 2011 American Chemical Society.

Windsor E.,U.S. National Institute of Standards and Technology | Najarro M.,U.S. National Institute of Standards and Technology | Bloom Jr. A.,U.S. National Institute of Standards and Technology | Benner B.,U.S. National Institute of Standards and Technology | And 3 more authors.
Analytical Chemistry | Year: 2010

The feasibility of the use of piezoelectric drop-on-demand inkjet printing to prepare test materials for trace explosive analysis is demonstrated. RDX (1,3,5-trinitro-1,3,5 triazcyclohexane) was formulated into inkjet printable solutions and jetted onto substrates suitable for calibration of the ion mobility spectrometry (IMS) instruments currently deployed worldwide for contraband screening. Gravimetric analysis, gas chromatography/mass spectrometry (GC/MS), and ultraviolet-visible (UV-vis) absorption spectroscopy were used to verify inkjet printer solution concentrations and the quantity of explosive dispensed onto test materials. Reproducibility of the inkjet printing process for mass deposition of the explosive RDX (1,3,5-trinitro-1,3,5 triazcyclohexane) was determined to be better than 2% for a single day of printing and better than 3% day-to-day. © This article not subject to U.S. Copyright. Published 2010 by the American Chemical Society.

Verkouteren J.R.,U.S. National Institute of Standards and Technology | Coleman J.L.,U.S. National Institute of Standards and Technology | Cho I.,Transportation Security Laboratory
Journal of Forensic Sciences | Year: 2010

A method is described to perform automated mapping of hexahydro-1,3,5- trinitro-1,3,5-triazine (RDX) particles in C-4 fingerprints. The method employs polarized light microscopy and image analysis to map the entire fingerprint and the distribution of RDX particles. This method can be used to evaluate a large number of fingerprints to aid in the development of threat libraries that can be used to determine performance requirements of explosive trace detectors. A series of 50 C-4 fingerprints were characterized, and results show that the number of particles varies significantly from print to print, and within a print. The particle size distributions can be used to estimate the mass of RDX in the fingerprint. These estimates were found to be within ±26% relative of the results obtained from dissolution gas chromatography/μ-electron capture detection for four of six prints, which is quite encouraging for a particle counting approach. By evaluating the average mass and frequency of particles with respect to size for this series of fingerprints, we conclude that particles 10-20 μm in diameter could be targeted to improve detection of traces of C-4 explosives. © 2010 American Academy of Forensic Sciences.

Rao E.,Transportation Security Administration | Remer J.,Transportation Security Laboratory
Proceedings - International Carnahan Conference on Security Technology | Year: 2014

The mitigation of threats posed by the potential introduction of improvised explosive devices into passenger aircraft via the cargo vector is the subject and driver of the Cargo Supply Chain Integrity Technology (CSIT) Research, Development, Test and Evaluation project undertaken jointly by the Transportation Security Administration (TSA) and the Department of Homeland Security's (DHS) Science and Technology (S&T) Directorate. Recognizing the security capability gap represented by unscreened cargo loaded into/ carried in the holds of passenger aircraft, section 1602(a) of the 'Implementing the Recommendations of the 9/11 Commission Act of 2007', (Public Law 110-53) mandated TSA to establish, by August 3, 2010, a system to screen 100% of all cargo shipped via passenger aircraft. The objective of the project is to develop standards and a process to evaluate and qualify technologies used to insure the security of screened cargo in transit to loading aboard aircraft. The initial phase consisted of a number of market surveys of existing cargo seal products that are commercially available. A web-based compilation of these surveys was established, which included a listing of relevant technical performance standards. Eight major classes of systems/devices were derived from these surveys as follows that included Tamper Evident Tapes and Labels, Mechanical and Electronic Lock Systems, and Other Technologies. The focus of this paper is to assess and evaluate secure locks in the chain of custody process. The process of laboratory and operational field testing of four main types of secure locks that were assessed will be detailed. The process included development of performance specifications, drawing from existing primary and secondary domestic and international standards, and evaluated test results. To date, testing and evaluation has been completed for electronic lock-based systems, identifying key performance parameters for the development of a draft standard. Other DHS secure conveyance and container initiatives by DHS Science and Technology for Custom Border and Patrol (CBP) that are related to this project will be briefly outlined. A key part of this project is the transfer of cargo seal certification/qualification laboratory testing from the DHS /TSA to private testing laboratories. The project is currently evaluating test laboratory certifications, standards, and processes, and enables TSA to qualify air cargo seal products to be used by regulated air cargo industry to ensure supply chain integrity in the Certified Cargo Screening Program (CCSP). This initiative is vital to meeting TSA's Air Cargo Congressional Cargo Mandate, as legislated in the 9-11 act, and providing the basis for longer term advancement of the technology of cargo supply chain integrity. © 2013 IEEE.

PubMed | Transportation Security Laboratory
Type: Journal Article | Journal: Applied spectroscopy | Year: 2015

The vibrational bands of erythritol tetranitrate (ETN) were measured experimentally with both Raman spectroscopy and attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy. Seventy-two (3N-6) vibrational modes were predicted for ETN using density functional theory calculations performed using the B3LYP/6-31G* density functional basis set and geometry optimization. Raman spectroscopy and ATR FT-IR were used to measure observable Raman and IR signatures between 140 and 3100 wavenumbers (cm(-1)). Within this spectral range, 32 Raman bands and 21 IR bands were measured and identified by their predicted vibrational motion. The spectroscopic and theoretical analysis of ETN performed will advance the detection and identification capabilities of field measuring instruments for this explosive.

PubMed | Kutztown University of Pennsylvania and Transportation Security Laboratory
Type: | Journal: Talanta | Year: 2015

The gas phase ion chemistry for an ion mobility spectrometer (IMS) based explosive detector has been elucidated using tandem mass spectrometry. The IMS system, which is operated with hexachloroethane and isobutyramide reagent gases and an ion shutter type gating scheme, is connected to the atmospheric pressure interface of a triple quadrupole mass spectrometer (MS/MS). Product ion masses, daughter ion masses, and reduced mobility values for a collection of nitro, nitrate, and peroxide explosives measured with the IMS/MS/MS instrument are reported. The mass and mobility data together with targeted isotopic labeling experiments and information about sample composition and reaction environment are leveraged to propose molecular formulas, structures, and ionization pathways for the various product ions. The major product ions are identified as [DNT-H](-) for DNT, [TNT-H](-) for TNT, [RDX+Cl](-) and [RDX+NO2](-) for RDX, [HMX+Cl](-) and [HMX+NO2](-) for HMX, [NO3](-) for EGDN, [NG+Cl](-) and [NG+NO3](-) for NG, [PETN+Cl](-) and [PETN+NO3](-) for PETN, [HNO3+NO3](-) for NH4NO3, [NO2](-) for DMNB, [HMTD-NC3H6O3+H+Cl](-) and [HMTD+H-CH2O-H2O2](+) for HMTD, and [(CH3)3CO2](+) for TATP. In general, the product ions identified for the IMS system studied here are consistent with the product ions reported previously for an ion trap mobility spectrometer (ITMS) based explosive trace detector, which is operated with dichloromethane and ammonia reagent gases and an ion trap type gating scheme. Differences between the explosive trace detectors include the [NG+Cl](-) and [PETN+Cl](-) product ions being major ions in the IMS system compared to minor ions in the ITMS system as well as the major product ion for TATP being [(CH3)3CO2](+) for the IMS system and [(CH3)2CNH2](+) for the ITMS system.

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