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Sample records for high explosive residues

  1. Differential spectroscopic imaging of particulate explosives residue

    NASA Astrophysics Data System (ADS)

    Bernacki, Bruce E.; Hô, Nicolas

    2008-04-01

    We present experimental results showing transmission and reflection imaging of approximately 100 μg quantities of particulate explosives residue using a commercial uncooled microbolometer infrared camera and CO II laser differential wavelength illumination. Fine particulates may be generated during bomb-making activities and these particulates can tenaciously adhere to packing material, as well as to the clothing or skin of the bomb maker and could be detectable during transportation. A rapid screening method that detects this residue can serve as a first-line screening method in conjunction with more sensitive, but invasive, approaches. Explosives exhibit absorption features in the mid-infrared molecular fingerprint region that spans 3 to 15 μm, which can be probed with many high-brightness sources such as fixed wavelength and tunable quantum cascade lasers, CO II, CO, and OPO lasers. Commercial uncooled microbolometer cameras typically have detection sensitivity from 7.5 to 13 μm, spanning an absorption region for explosives detection with adequate signal-to-noise ratio. By illuminating a target on and off its absorption wavelengths, ratio images of suspected residue can be obtained without any sample preparation or cooperation and contact with the target. Our proof-of-principle experiment employed tunable CO II lasers, with a tuning range from 9.2 to 10.6 μm, overlapping minor absorption features of RDX and Tetryl.

  2. SOLID PHASE MICROEXTRACTION SAMPLING OF HIGH EXPLOSIVE RESIDUES IN THE PRESENCE OF RADIONUCLIDES AND RADIONUCLIDE SURROGATE METALS

    SciTech Connect

    Duff, M; S Crump, S; Robert02 Ray, R; Donna Beals, D

    2007-04-13

    The Federal Bureau of Investigation (FBI) Laboratory currently does not have on site facilities for handling radioactive evidentiary materials and there are no established FBI methods or procedures for decontaminating high explosive (HE) evidence while maintaining evidentiary value. One experimental method for the isolation of HE residue involves using solid phase microextraction or SPME fibers to remove residue of interest. Due to their high affinity for organics, SPME fibers should have little affinity for most metals. However, no studies have measured the affinity of radionuclides for SPME fibers. The focus of this research was to examine the affinity of dissolved radionuclide ({sup 239/240}Pu, {sup 238}U, {sup 237}Np, {sup 85}Sr, {sup 133}Ba, {sup 137}Cs, {sup 60}Co and {sup 226}Ra) and stable radionuclide surrogate metals (Sr, Co, Ir, Re, Ni, Ba, Cs, Nb, Zr, Ru, and Nd) for SPME fibers at the exposure conditions that favor the uptake of HE residues. Our results from radiochemical and mass spectrometric analyses indicate these metals have little measurable affinity for these SPME fibers during conditions that are conducive to HE residue uptake with subsequent analysis by liquid or gas phase chromatography with mass spectrometric detection.

  3. Differential Spectroscopic Imaging of Particulate Explosives Residue

    SciTech Connect

    Bernacki, Bruce E.; Ho, Nicolas

    2008-04-01

    We present experimental results showing transmission and reflection imaging of approximately 100 microgram quantities of particulate explosives residue using a commercial uncooled microbolometer infrared camera and CO2 laser differential wavelength illumination.

  4. Bioremediation of high explosives

    SciTech Connect

    Kitts, C.L.; Alvarez, M.A.; Hanners, J.L.; Ogden, K.L.; Vanderberg-Twary, L.; Unkefer, P.J.

    1995-09-01

    Manufacture and use of high explosives has resulted in contamination of ground water and soils throughout the world. The use of biological methods for remediation of high explosives contamination has received considerable attention in recent years. Biodegradation is most easily studied using organisms in liquid cultures. Thus, the amount of explosive that can be degraded in liquid culture is quite small. However, these experiments are useful for gathering basic information about the biochemical pathways of biodegradation, identifying appropriate organisms and obtaining rates of degradation. The authors` laboratory has investigated all three major areas of explosives bioremediation: explosives in solution, explosives in soil, and the disposal of bulk explosives from demilitarization operations. They investigated the three explosives most commonly used in modern high explosive formulations: 2,4,6-trinitrotoluene (TNT), hexahydro 1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX).

  5. Infrared Spectroscopy of Explosives Residues: Measurement Techniques and Spectral Analysis

    SciTech Connect

    Phillips, Mark C.; Bernacki, Bruce E.

    2015-03-11

    Infrared laser spectroscopy of explosives is a promising technique for standoff and non-contact detection applications. However, the interpretation of spectra obtained in typical standoff measurement configurations presents numerous challenges. Understanding the variability in observed spectra from explosives residues and particles is crucial for design and implementation of detection algorithms with high detection confidence and low false alarm probability. We discuss a series of infrared spectroscopic techniques applied toward measuring and interpreting the reflectance spectra obtained from explosives particles and residues. These techniques utilize the high spectral radiance, broad tuning range, rapid wavelength tuning, high scan reproducibility, and low noise of an external cavity quantum cascade laser (ECQCL) system developed at Pacific Northwest National Laboratory. The ECQCL source permits measurements in configurations which would be either impractical or overly time-consuming with broadband, incoherent infrared sources, and enables a combination of rapid measurement speed and high detection sensitivity. The spectroscopic methods employed include standoff hyperspectral reflectance imaging, quantitative measurements of diffuse reflectance spectra, reflection-absorption infrared spectroscopy, microscopic imaging and spectroscopy, and nano-scale imaging and spectroscopy. Measurements of explosives particles and residues reveal important factors affecting observed reflectance spectra, including measurement geometry, substrate on which the explosives are deposited, and morphological effects such as particle shape, size, orientation, and crystal structure.

  6. Development in the Detection and Identification of Explosive Residues.

    PubMed

    Beveridge, A D

    1992-06-01

    In the past 2 decades, developments in the sensitivity and selectivity of instrument detectors have significantly improved the detection limits for explosives, particularly nitrated organic compounds. Significant improvements have also been made in clean up and recovery procedures for explosive residues. Methods which also have met the criterion of proven effectiveness in identifying explosive components in "real-world" residues from test explosions have been incorporated into systematic analysis protocols for explosive residues. This article first reviews developments in the application of both traditional and novel methods to analysis of unreacted explosives and explosive residues. Compounds used to formulate commercial, military, and "homemade" explosives are then cross-referenced to the analytical methods that have been specifically applied to them, both as pure chemicals and in explosive mixtures. The subsequent focus is on the combinations of methods used to systematically analyze and positively identify residues from improvised explosive devices, from handswabs derived from persons suspected of handling explosives, and from organic gunshot residue. Technology is available to positively identify virtually any unreacted explosive in residue, but no one method can detect all components of all explosives. Investigators and the courts are best served by well-equipped forensic science laboratories staffed with scientists who have gained experience by the successful analysis of post-blast residues from an explosives range and have comprehensive reference collections of physical material, analytical data, and literature. The greatest progress has been made with respect to nitrated organic compounds, but the new generation of commercial explosive slurries and emulsions which are primarily formulated with inorganic salts and non-nitrated organic compounds offer an ongoing challenge. PMID:26267286

  7. High-nitrogen explosives

    SciTech Connect

    Naud, D.; Hiskey, M. A.; Kramer, J. F.; Bishop, R. L.; Harry, H. H.; Son, S. F.; Sullivan, G. K.

    2002-01-01

    The syntheses and characterization of various tetrazine and furazan compounds offer a different approach to explosives development. Traditional explosives - such as TNT or RDX - rely on the oxidation of the carbon and hydrogen atoms by the oxygen carrying nitro group to produce the explosive energy. High-nitrogen compounds rely instead on large positive heats of formation for that energy. Some of these high-nitrogen compounds have been shown to be less sensitive to initiation (e.g. by impact) when compared to traditional nitro-containing explosives of similar performances. Using the precursor, 3,6-bis-(3,5-dimethylpyrazol-1-yl)-s-tetrazine (BDT), several useful energetic compounds based on the s-tetrazine system have been synthesized and studied. The compound, 3,3{prime}-azobis(6-amino-s-tetrazine) or DAAT, detonates as a half inch rate stick despite having no oxygen in the molecule. Using perfluoroacetic acid, DAAT can be oxidized to give mixtures of N-oxide isomers (DAAT03.5) with an average oxygen content of about 3.5. This energetic mixture burns at extremely high rates and with low dependency on pressure. Another tetrazine compound of interest is 3,6-diguanidino-s-tetrazine(DGT) and its dinitrate and diperchlorate salts. DGT is easily synthesized by reacting BDT with guanidine in methanol. Using Caro's acid, DGT can be further oxidized to give 3,6-diguanidino-s-tetrazine-1,4-di-N-oxide (DGT-DO). Like DGT, the di-N-oxide can react with nitric acid or perchloric acid to give the dinitrate and the diperchlorate salts. The compounds, 4,4{prime}-diamino-3,3{prime}-azoxyfurazan (DAAF) and 4,4{prime}-diamino-3,3{prime}-azofurazan (DAAzF), may have important future roles in insensitive explosive applications. Neither DAAF nor DAAzF can be initiated by laboratory impact drop tests, yet both have in some aspects better explosive performances than 1,3,5-triamino-2,4,6-trinitrobenzene TATB - the standard of insensitive high explosives. The thermal stability of DAAzF is

  8. Novel high explosive compositions

    DOEpatents

    Perry, D.D.; Fein, M.M.; Schoenfelder, C.W.

    1968-04-16

    This is a technique of preparing explosive compositions by the in-situ reaction of polynitroaliphatic compounds with one or more carboranes or carborane derivatives. One or more polynitroaliphatic reactants are combined with one or more carborane reactants in a suitable container and mixed to a homogeneous reaction mixture using a stream of inert gas or conventional mixing means. Ordinarily the container is a fissure, crack, or crevice in which the explosive is to be implanted. The ratio of reactants will determine not only the stoichiometry of the system, but will effect the quality and quantity of combustion products, the explosive force obtained as well as the impact sensitivity. The test values can shift with even relatively slight changes or modifications in the reaction conditions. Eighteen illustrative examples accompany the disclosure. (46 claims)

  9. High Explosive Radio Telemetry System

    SciTech Connect

    Bracht, R.R.; Crawford, T.R.; Johnson, R.L.; Mclaughlin, B.M.

    1998-11-04

    This paper overviews the High Explosive Radio Telemetry (HERT) system, under co-development by Los Alamos National Laboratories and Allied Signal Federal Manufacturing & Technologies. This telemetry system is designed to measure the initial performance of an explosive package under flight environment conditions, transmitting data from up to 64 sensors. It features high speed, accurate time resolution (10 ns) and has the ability to complete transmission of data before the system is destroyed by the explosion. In order to affect the resources and performance of a flight delivery vehicle as little as possible, the system is designed such that physical size, power requirements, and antenna demands are as small as possible.

  10. High explosive compound

    DOEpatents

    Crawford, Theodore C.

    1976-01-01

    1. A low detonation velocity explosive consisting essentially of a particulate mixture of ortho-boric acid and trinitrotoluene, said mixture containing from about 25 percent to about 65 percent by weight of ortho-boric acid, said ortho-boric acid comprised of from 60 percent to 90 percent of spherical particles having a mean particle size of about 275 microns and 10 percent to 40 percent of spherical particles having a particle size less than about 44 microns.

  11. Detection of residues from explosive manipulation by near infrared hyperspectral imaging: a promising forensic tool.

    PubMed

    Fernández de la Ossa, Ma Ángeles; Amigo, José Manuel; García-Ruiz, Carmen

    2014-09-01

    In this study near infrared hyperspectral imaging (NIR-HSI) is used to provide a fast, non-contact, non-invasive and non-destructive method for the analysis of explosive residues on human handprints. Volunteers manipulated individually each of these explosives and after deposited their handprints on plastic sheets. For this purpose, classical explosives, potentially used as part of improvised explosive devices (IEDs) as ammonium nitrate, blackpowder, single- and double-base smokeless gunpowders and dynamite were studied. A partial-least squares discriminant analysis (PLS-DA) model was built to detect and classify the presence of explosive residues in handprints. High levels of sensitivity and specificity for the PLS-DA classification model created to identify ammonium nitrate, blackpowder, single- and double-base smokeless gunpowders and dynamite residues were obtained, allowing the development of a preliminary library and facilitating the direct and in situ detection of explosives by NIR-HSI. Consequently, this technique is showed as a promising forensic tool for the detection of explosive residues and other related samples. PMID:25086347

  12. Standoff detection of explosive residues on unknown surfaces

    NASA Astrophysics Data System (ADS)

    Van Neste, C. W.; Liu, Xunchen; Gupta, Manisha; Kim, Seonghwan; Tsui, Ying; Thundat, T.

    2012-06-01

    Standoff identification of explosive residues may offer early warnings to many hazards plaguing present and future military operations. The greatest challenge is posed by the need for molecular recognition of trace explosive compounds on real-world surfaces. Most techniques that offer eye-safe, long-range detection fail when unknown surfaces with no prior knowledge of the surface spectral properties are interrogated. Inhomogeneity in the surface concentration and optical absorption from background molecules can introduce significant reproducibility challenges for reliable detection when surface residue concentrations are below tens of micrograms per square centimeter. Here we present a coupled standoff technique that allows identification of explosive residues concentrations in the sub microgram per square centimeter range on real-world surfaces. Our technique is a variation of standoff photoacoustic spectroscopy merged with ultraviolet chemical photodecomposition for selective identification of explosives. We demonstrate the detection of standard military grade explosives including RDX, PETN, and TNT along with a couple of common compounds such as diesel and sugar. We obtain identification at several hundred nanograms per centimeter square at a distance of four meters.

  13. Nanoplasmonic imaging of latent fingerprints with explosive RDX residues.

    PubMed

    Peng, Tianhuan; Qin, Weiwei; Wang, Kun; Shi, Jiye; Fan, Chunhai; Li, Di

    2015-09-15

    Explosive detection is a critical element in preventing terrorist attacks, especially in crowded and influential areas. It is probably more important to establish the connection of explosive loading with a carrier's personal identity. In the present work, we introduce fingerprinting as physical personal identification and develop a nondestructive nanoplasmonic method for the imaging of latent fingerprints. We further integrate the nanoplasmonic response of catalytic growth of Au NPs with NADH-mediated reduction of 1,3,5-trinitro-1,3,5-triazinane (RDX) for the quantitative analysis of RDX explosive residues in latent fingerprints. This generic nanoplasmonic strategy is expected to be used in forensic investigation to distinguish terrorists that carry explosives. PMID:26292147

  14. Field recovery of explosive residues using solid-phase microextraction followed by chromatographic analysis

    NASA Astrophysics Data System (ADS)

    Almirall, Jose R.; Wu, Lianming; Bi, Grace; Shannon, Michael W.; Furton, Kenneth G.

    1999-02-01

    An inexpensive, rapid and sensitive method for the field pre-concentration and subsequent analysis of high explosive residues from solid debris samples and from aqueous samples has been evaluated using solid-phase microextraction. Explosives studied included nitrobenzene, 2-nitrotoluene, 3- nitrotoluene, 4-nitrotoluene, 2,6-dinitrotoluene, 1,3- dinitrobenzene, 2,4-dinitrotoluene, trinitrotoluene, 1,3,5- trinitrobenzene, 4-amino-2,6-dinitrotoluene, 2-amino-4,6- dinitrotolene and tetryl.

  15. Residual Stress Measurements of Explosively Clad Cylindrical Pressure Vessels

    SciTech Connect

    Taylor, Douglas J; Watkins, Thomas R; Hubbard, Camden R; Hill, M. R.; Meith, W. A.

    2012-01-01

    Tantalum refractory liners were explosively clad into cylindrical pressure vessels, some of which had been previously autofrettaged. Using explosive cladding, the refractory liner formed a metallurgical bond with the steel of the pressure vessel at a cost of induced strain. Two techniques were employed to determine the residual stress state of the clad steel cylinders: neutron diffraction and mechanical slitting. Neutron diffraction is typically nondestructive; however, due to attenuation along the beam path, the cylinders had to be sectioned into rings that were nominally 25 mm thick. Slitting is a destructive method, requiring the sectioning of the cylindrical samples. Both techniques provided triaxial stress data and useful information on the effects of explosive cladding. The stress profiles in the hoop and radial directions were similar for an autofrettaged, nonclad vessel and a clad, nonautofrettaged vessel. The stress profiles in the axial direction appeared to be different. Further, the data suggested that residual stresses from the autofrettage and explosive cladding processes were not additive, in part due to evidence of reverse yielding. The residual stress data are presented, compared and discussed.

  16. Insensitive fuze train for high explosives

    DOEpatents

    Cutting, Jack L.; Lee, Ronald S.; Von Holle, William G.

    1994-01-01

    A generic insensitive fuze train to initiate insensitive high explosives, such as PBXW-124. The insensitive fuze train uses a slapper foil to initiate sub-gram quantities of an explosive, such as HNS-IV or PETN. This small amount of explosive drives a larger metal slapper onto a booster charge of an insensitive explosive, such as UF-TATB. The booster charge initiates a larger charge of an explosive, such as LX-17, which in turn, initiates the insensitive high explosive, such as PBXW-124.

  17. Insensitive fuze train for high explosives

    DOEpatents

    Cutting, J.L.; Lee, R.S.; Von Holle, W.G.

    1994-01-04

    A generic insensitive fuze train to initiate insensitive high explosives, such as PBXW-124 is described. The insensitive fuze train uses a slapper foil to initiate sub-gram quantities of an explosive, such as HNS-IV or PETN. This small amount of explosive drives a larger metal slapper onto a booster charge of an insensitive explosive, such as UF-TATB. The booster charge initiates a larger charge of an explosive, such as LX-17, which in turn, initiates the insensitive high explosive, such as PBXW-124. 3 figures.

  18. The spatial distribution patterns of condensed phase post-blast explosive residues formed during detonation.

    PubMed

    Abdul-Karim, Nadia; Blackman, Christopher S; Gill, Philip P; Karu, Kersti

    2016-10-01

    The continued usage of explosive devices, as well as the ever growing threat of 'dirty' bombs necessitates a comprehensive understanding of particle dispersal during detonation events in order to develop effectual methods for targeting explosive and/or additive remediation efforts. Herein, the distribution of explosive analytes from controlled detonations of aluminised ammonium nitrate and an RDX-based explosive composition were established by systematically sampling sites positioned around each firing. This is the first experimental study to produce evidence that the post-blast residue mass can distribute according to an approximate inverse-square law model, while also demonstrating for the first time that distribution trends can vary depending on individual analytes. Furthermore, by incorporating blast-wave overpressure measurements, high-speed imaging for fireball volume recordings, and monitoring of environmental conditions, it was determined that the principle factor affecting all analyte dispersals was the wind direction, with other factors affecting specific analytes to varying degrees. The dispersal mechanism for explosive residue is primarily the smoke cloud, a finding which in itself has wider impacts on the environment and fundamental detonation theory. PMID:27236429

  19. High temperature two component explosive

    DOEpatents

    Mars, James E.; Poole, Donald R.; Schmidt, Eckart W.; Wang, Charles

    1981-01-01

    A two component, high temperature, thermally stable explosive composition comprises a liquid or low melting oxidizer and a liquid or low melting organic fuel. The oxidizer and fuel in admixture are incapable of substantial spontaneous exothermic reaction at temperatures on the order of 475.degree. K. At temperatures on the order of 475.degree. K., the oxidizer and fuel in admixture have an activation energy of at least about 40 kcal/mol. As a result of the high activation energy, the preferred explosive compositions are nondetonable as solids at ambient temperature, and become detonable only when heated beyond the melting point. Preferable oxidizers are selected from alkali or alkaline earth metal nitrates, nitrites, perchlorates, and/or mixtures thereof. Preferred fuels are organic compounds having polar hydrophilic groups. The most preferred fuels are guanidinium nitrate, acetamide and mixtures of the two. Most preferred oxidizers are eutectic mixtures of lithium nitrate, potassium nitrate and sodium nitrate, of sodium nitrite, sodium nitrate and potassium nitrate, and of potassium nitrate, calcium nitrate and sodium nitrate.

  20. Ignition dynamics of high explosives

    SciTech Connect

    Ali, A.N.; Son, S.F.; Sander, R.K.; Asay, B.W.

    1998-12-31

    Mechanical insults of granular high explosives (HE) can result in localized areas of elevated temperature, or hot spots. The evolution of these hot spots is a central issue of HE science. Because of the complexity involved, it is worthwhile to study mechanical and reaction processes in isolation. Mechanical processes are isolated and studied using inert materials or weak insults where reaction may be minimal. Likewise, purely thermal processes can be considered to isolate HE reaction response. In this work the authors study the radiant ignition of various HEs of interest, including HMX (C{sub 4}H{sub 8}N{sub 8}O{sub 8}), PBX 9501 (95% HMX, 2.5% Estane, 2.5% BDNPA/BDNPF), RDX (C{sub 3}H{sub 6}N{sub 6}O{sub 6}), TATB (C{sub 6}H{sub 6}N{sub 6}O{sub 6}), and PBX 9502 (95% TATB, 5% Kel-F) and aged PBX 9502. Initial work has included unconfined samples at ambient pressure in air. Diagnostics have included photodiodes to record first light emission, high speed photography, microthermocouple and IR emission measurement to obtain surface temperature, IR emission of gases above the pellet, and a novel nonlinear optical technique to characterize the dynamic {beta}-{delta} solid phase transformation and the formation of a liquid layer. The authors find that ignition delays at various power levels is very similar for HMX and RDX; except that the minimum radiant flux needed for RDX ignition is higher. The addition of only 5% binder (PBX 9501) causes significantly longer ignition delays at lower heat fluxes compared with HMX alone. TATB and TATB-based explosives exhibit much longer ignition delays than HMX. In contrast to HMX, however, no measurable difference is observed in TATB by the addition of a binder (PBX 9502, aged or pristine).

  1. Apparatus and method for rapid detection of explosives residue from the deflagration signature thereof

    DOEpatents

    Funsten, H.O.; McComas, D.J.

    1999-06-15

    Apparatus and method are disclosed for rapid detection of explosives residue from the deflagration signature thereof. A property inherent to most explosives is their stickiness, resulting in a strong tendency of explosive particulate to contaminate the environment of a bulk explosive. An apparatus for collection of residue particulate, burning the collected particulate, and measurement of the ultraviolet emission produced thereby, is described. The present invention can be utilized for real-time screening of personnel, cars, packages, suspected devices, etc., and provides an inexpensive, portable, and noninvasive means for detecting explosives. 4 figs.

  2. Apparatus and method for rapid detection of explosives residue from the deflagration signature thereof

    DOEpatents

    Funsten, Herbert O.; McComas, David J.

    1997-01-01

    Apparatus and method for rapid detection of explosives residue from the deflagration signature thereof. A property inherent to most explosives is their stickiness, resulting in a strong tendency of explosive particulate to contaminate the environment of a bulk explosive. An apparatus for collection of residue particulate, burning the collected particulate, and measurement of the optical emission produced thereby is described. The present invention can be utilized for real-time screening of personnel, cars, packages, suspected devices, etc., and provides an inexpensive, portable, and noninvasive means for detecting explosives.

  3. Apparatus and method for rapid detection of explosives residue from the deflagration signature thereof

    DOEpatents

    Funsten, Herbert O.; McComas, David J.

    1999-01-01

    Apparatus and method for rapid detection of explosives residue from the deflagration signature thereof. A property inherent to most explosives is their stickiness, resulting in a strong tendency of explosive particulate to contaminate the environment of a bulk explosive. An apparatus for collection of residue particulate, burning the collected particulate, and measurement of the ultraviolet emission produced thereby, is described. The present invention can be utilized for real-time screening of personnel, cars, packages, suspected devices, etc., and provides an inexpensive, portable, and noninvasive means for detecting explosives.

  4. Explosives detection portal for high-volume personnel screening

    NASA Astrophysics Data System (ADS)

    Parmeter, John E.; Linker, Kevin L.; Rhykerd, Charles L.; Hannum, David W.; Bouchier, Francis A.

    1998-12-01

    We discuss a trace explosive detection portal for high-volume personnel screening, which has been developed recently at Sandia National Laboratories (SNL), using funding provided by the Federal Aviation Administration (FAA) and the Department of Energy (DOE) Office of Safeguards and Security (OSS). This portal screens individuals for explosives using noninvasive means to collect explosive residue in the forms of vapor and particulate contamination. The portal combines a commercially available ion mobility spectrometer (IMS) with a preconcentrator developed at SNL to perform detection of explosives. The prototype portal has undergone one series of tests at the Albuquerque International Airport, and we are now proceeding to develop an improved, second-generation portal, and to find a company to market the portal.

  5. High-explosive driven crowbar switch

    DOEpatents

    Dike, Robert S.; Kewish, Jr., Ralph W.

    1976-01-13

    The disclosure relates to a compact explosive driven switch for use as a low resistance, low inductance crowbar switch. A high-explosive charge extrudes a deformable conductive metallic plate through a polyethylene insulating layer to achieve a hard current contact with a supportive annular conductor.

  6. Detonation in shocked homogeneous high explosives

    SciTech Connect

    Yoo, C.S.; Holmes, N.C.; Souers, P.C.

    1995-11-01

    We have studied shock-induced changes in homogeneous high explosives including nitromethane, tetranitromethane, and single crystals of pentaerythritol tetranitrate (PETN) by using fast time-resolved emission and Raman spectroscopy at a two-stage light-gas gun. The results reveal three distinct steps during which the homogeneous explosives chemically evolve to final detonation products. These are (1) the initiation of shock compressed high explosives after an induction period, (2) thermal explosion of shock-compressed and/or reacting materials, and (3) a decay to a steady-state representing a transition to the detonation of uncompressed high explosives. Based on a gray-body approximation, we have obtained the CJ temperatures: 3800 K for nitromethane, 2950 K for tetranitromethane, and 4100 K for PETN. We compare the data with various thermochemical equilibrium calculations. In this paper we will also show a preliminary result of single-shot time-resolved Raman spectroscopy applied to shock-compressed nitromethane.

  7. Transport of Explosive Residue Surrogates in Saturated Porous Media

    SciTech Connect

    Lavoie, Bethsheba; Mayes, Melanie; McKay, Larry Donald

    2011-01-01

    Department of Defense operational ranges may become contaminated by particles of explosives residues (ER) as a result of low-order detonations of munitions. The goal of this study was to determine the extent to which particles of ER could migrate through columns of sandy sediment, representing model aquifer materials. Transport experiments were conducted in saturated columns (2 x 20 cm) packed with different grain sizes of clean sand or glass beads. Fine particles (approximately 2 to 50 {mu}m) of 2,6-dinitrotoluene (DNT) were used as a surrogate for ER. DNT particles were applied to the top 1 cm of sand or beads in the columns, and the columns were subsequently leached with artificial groundwater solutions. DNT migration occurred as both dissolved and particulate phases. Concentration differences between unfiltered and filtered samples indicate that particulate DNT accounted for up to 41% of the mass recovered in effluent samples. Proportionally, more particulate than dissolved DNT was recovered in effluent solutions from columns with larger grain sizes, while total concentrations of DNT in effluent were inversely related to grain size. Of the total DNT mass applied to the uppermost layer of the column, <3% was recovered in the effluent with the bulk remaining in the top 2 cm of the column. Our results suggest there is some potential for subsurface migration of ER particles and that most of the particles will be retained over relatively short transport distances.

  8. Evaluation of femtosecond laser-induced breakdown spectroscopy for explosive residue detection.

    PubMed

    De Lucia, Frank C; Gottfried, Jennifer L; Miziolek, Andrzej W

    2009-01-19

    Recently laser-induced breakdown spectroscopy (LIBS) has been investigated as a potential technique for trace explosive detection. Typically LIBS is performed using nanosecond laser pulses. For this work, we have investigated the use of femtosecond laser pulses for explosive residue detection at two different fluences. Femtosecond laser pulses have previously been shown to provide several advantages for laser ablation and other LIBS applications. We have collected LIBS spectra of several bulk explosives and explosive residues at different pulse durations and energies. In contrast to previous femtosecond LIBS spectra of explosives, we have observed atomic emission peaks for the constituent elements of explosives - carbon, hydrogen, nitrogen, and oxygen. Preliminary results indicate that several advantages attributed to femtosecond pulses are not realized at higher laser fluences. PMID:19158854

  9. On the Violence of High Explosive Reactions

    SciTech Connect

    Tarver, C M; Chidester, S K

    2004-02-09

    High explosive reactions can be caused by three general energy deposition processes: impact ignition by frictional and/or shear heating; bulk thermal heating; and shock compression. The violence of the subsequent reaction varies from benign slow combustion to catastrophic detonation of the entire charge. The degree of violence depends on many variables, including the rate of energy delivery, the physical and chemical properties of the explosive, and the strength of the confinement surrounding the explosive charge. The current state of experimental and computer modeling research on the violence of impact, thermal, and shock-induced reactions is reviewed.

  10. Classification of explosive residues on organic substrates using laser induced breakdown spectroscopy.

    PubMed

    De Lucia, Frank C; Gottfried, Jennifer L

    2012-03-01

    Standoff laser induced breakdown spectroscopy (LIBS) has previously been used to classify trace residues as either hazardous (explosives, biological, etc.) or benign. Correct classification can become more difficult depending on the surface/substrate underneath the residue due to variations in the laser-material interaction. In addition, classification can become problematic if the substrate material has a similar elemental composition to the residue. We have evaluated coupling multivariate analysis with standoff LIBS to determine the effectiveness of classifying thin explosive residue layers on painted surfaces. Good classification results were obtained despite the fact that the painted surface contributes to the LIBS emission signal. PMID:22410930

  11. High explosives skid impact initiation study

    SciTech Connect

    Vigil, A.S.; Bunch, J.M.; Jaeger, D.L.; Smith, P.D.; Abeyta, E.E.

    1990-06-01

    The objective of this study was to develop a better quantitative understanding of explosive behavior under skid impact conditions. We evaluated the effects of sample weight, impact velocity, contact surface area at impact, target surface roughness, and target material on the skid impact HE ignition threshold. We also quantified the effects of two parameters that had never been fully investigated in the standard skid impact sensitivity test: explosive sample size and angle of incidence. These parameters were studied experimentally by conducting a series of tests, and analytical, with a number of one-, two-, and three-dimensional computer models. This study is the first phase in a program to measure the transient heat produced in the ignition of a high explosive sample as it impacts an infrared (IR) transmissive target. We will use the experimentally derived data to enhance our ability to predict the onset of ignition in impact-heated high explosives. 12 refs., 9 figs., 2 tabs.

  12. Ignition dynamics of high explosives

    SciTech Connect

    Ali, A.N.; Son, S.F.; Sander, R.K.; Asay, B.W.; Brewster, M.Q.

    1999-04-01

    The laser ignition of the explosives HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine, C{sub 4}H{sub 8}N{sub 8}O{sub 8}), {delta}-phase HMX, PBX 9501 (95% HMX, 2.5% Estane, 2.5% BDNPA/BDNPF), TATB (1,3,5-triamino-2,4,6-trinitrobenzene, C{sub 6}H{sub 6}N{sub 6}O{sub 6}), and PBX 9502 (95% TATB, 5% Kel-F) and aged PBX 9502 has been conducted with the intent to compare the relative sensitivities of those explosives and to investigate the effect of beam profile, binder addition, and porosity. It has been found that there was little difference between a gaussian beam and a top hat profile on the laser ignition of HMX. The authors observe that the addition of binder in the amounts present in PBX 9501 resulted in longer ignition delays than that of HMX. In contrast to HMX, the addition of binder to TATB in PBX 9502 shows no measurable effect. Porosity effects were considered by comparing the ignition of granular HMX and pressed HMX pellets. Porosity appears to increase ignition delay due to an increased effective absorption scale and increased convective heat loss. This porosity effect also resulted in longer ignition delays for {delta}-phase HMX than for {beta}-phase HMX. In order to simulate ignition in voids or cracks, the standard ignition experiment was modified to include a NaCl window placed at variable distances above the sample surface. When ignition experiments were performed at 29 W/cm{sup 2} and 38 W/cm{sup 2} a critical gap distance was observed of 6 {+-} 0.4 mm below which ignition was severely inhibited. This result underscores the importance of gas phase processes in ignition and illustrates that conditions can exist where simple ignition criteria such as surface temperature is inadequate.

  13. Identification of improvised explosives residues using physical-chemical analytical methods under real conditions after an explosion

    NASA Astrophysics Data System (ADS)

    Kotrlý, Marek; Mareš, Bohumil; Turková, Ivana; Beroun, Ivo

    2016-05-01

    Within the analysis of cases relating to the use of explosives for crimes, we have experienced a shift from using industrial explosives towards substances made in amateur and illegal way. Availability of industrial explosives is increasingly limited to a narrow sphere of subjects with a relevant permission. Thus, on the part of perpetrators, terrorists, ever greater attention is paid to illegal production of explosives that are easily made from readily available raw materials. Another alarming fact is the availability of information found on the internet. Procedures of preparation are often very simple and do not require even a deeper professional knowledge. Explosive characteristics are not actually accessible for many of these substances (detonation velocity, sensitivity, working capacity, brisance, physical and chemical stability, etc.). Therefore, a project is being implemented, which on grounds of assessment of individual information available in literature and on the internet, aiming at choosing individual areas of potentially abusable substances (e.g. mixtures of nitric acid (98%) with organic substances, mixtures nitromethane and tetranitromethane with organic substances, mixtures of chlorates and perchlorates of alkali metals with organic substances, chemically individual compounds of organic base type of perchloric acid, azides, fulminates, acetylides, picrates, styphnates of heavy metals, etc.). It is directed towards preparation of these explosives also in non-stoichiometric mixtures, conducting test explosives, determination of explosive characteristics (if they are unknown) and analysis of both primary phases and post-blast residues through available analytical techniques, such as gas and liquid chromatography with mass detection, FTIR, micro-Raman spectrometry, electron microscopy with microanalysis and Raman microspectrometry directly in SEM chamber for analysis at the level of individual microparticles. The received characteristics will be used to

  14. Influence of steam explosion pretreatment on the anaerobic digestion of vinegar residue.

    PubMed

    Feng, Jiayu; Zhang, Jiyu; Zhang, Jiafu; He, Yanfeng; Zhang, Ruihong; Liu, Guangqing; Chen, Chang

    2016-07-01

    Vinegar residue is the by-product in the vinegar production process. The large amount of vinegar residue has caused a serious environmental problem owing to its acidity and corrosiveness. Anaerobic digestion is an effective way to convert agricultural waste into bioenergy, and a previous study showed that vinegar residue could be treated by anaerobic digestion but still had room to improve digestion efficiency. In this study, steam explosion at pressure of 0.8, 1.2, and 1.5 MPa and residence time of 5, 10, 15, and 20 min were used to pretreat vinegar residue to improve methane production, respectively. Scanning electron microscopy and X-ray diffraction analyses were applied to validate structural changes of vinegar residue after steam explosion. Results showed that steam explosion pretreatment could destroy the structure of lignocellulose by removing the hemicellulose and lignin, and improve the methane yield effectively. Steam explosion-treated vinegar residue at 0.8 MPa for 5 min produced the highest methane yield of 153.58 mL gVS (-1), which was 27.65% (significant, α < 0.05) more than untreated vinegar residue (120.31 mL gVS (-1)). The analyses of pH, total ammonia-nitrogen, total alkalinity, and volatile fatty acids showed that steam explosion did not influence the stability of anaerobic digestion. This study suggested that steam explosion pretreatment on vinegar residue might be a promising approach and it is worth further study to improve the efficiency of vinegar residue waste utilisation. PMID:27154975

  15. Explosive-driven, high speed, arcless switch

    DOEpatents

    Skogmo, P.J.; Tucker, T.J.

    1986-05-02

    An explosive-actuated, fast-acting arcless switch contains a highly conductive foil to carry high currents positioned adjacent a dielectric surface within a casing. At one side of the foil opposite the dielectric surface is an explosive which, when detonated, drives the conductive foil against the dielectric surface. A pattern of grooves in the dielectric surface ruptures the foil to establish a rupture path having a pattern corresponding to the pattern of the grooves. The impedance of the ruptured foil is greater than that of the original foil to divert high current to a load. Planar and cylindrical embodiments of the switch are disclosed.

  16. Explosive-driven, high speed, arcless switch

    DOEpatents

    Skogmo, P.J.; Tucker, T.J.

    1987-07-14

    An explosive-actuated, fast-acting arcless switch contains a highly conductive foil to carry high currents positioned adjacent a dielectric surface within a casing. At one side of the foil opposite the dielectric surface is an explosive which, when detonated, drives the conductive foil against the dielectric surface. A pattern of grooves in the dielectric surface ruptures the foil to establish a rupture path having a pattern corresponding to the pattern of the grooves. The impedance of the ruptured foil is greater than that of the original foil to divert high current to a load. Planar and cylindrical embodiments of the switch are disclosed. 7 figs.

  17. Explosive-driven, high speed, arcless switch

    DOEpatents

    Skogmo, Phillip J.; Tucker, Tillman J.

    1987-01-01

    An explosive-actuated, fast-acting arcless switch contains a highly conductive foil to carry high currents positioned adjacent a dielectric surface within a casing. At one side of the foil opposite the dielectric surface is an explosive which, when detonated, drives the conductive foil against the dielectric surface. A pattern of grooves in the dielectric surface ruptures the foil to establish a rupture path having a pattern corresponding to the pattern of the grooves. The impedance of the ruptured foil is greater than that of the original foil to divert high current to a load. Planar and cylindrical embodiments of the switch are disclosed.

  18. Study on metal foil explosion using high current

    NASA Astrophysics Data System (ADS)

    Mihara, Takayuki; Matsuo, N.; Otsuka, M.; Itoh, S.

    2009-12-01

    In the high energy processing using explosive, there are variety of application examples which is explosion welding of differential metallic plate and powder compaction of diamond. However a rule legal to explosives is severe and needs many efforts for handling qualification acquisition, maintenance, and security. In this research, the metallic foil explosion using high current is paid my attention to the method to obtain linear or planate explosive initiation easily, and the main evaluation of metallic foil explosion was conducted. The explosion power was evaluated by observing optically the underwater shock wave generated from the metallic foil explosion.

  19. Study on metal foil explosion using high current

    NASA Astrophysics Data System (ADS)

    Mihara, Takayuki; Matsuo, N.; Otsuka, M.; Itoh, S.

    2010-03-01

    In the high energy processing using explosive, there are variety of application examples which is explosion welding of differential metallic plate and powder compaction of diamond. However a rule legal to explosives is severe and needs many efforts for handling qualification acquisition, maintenance, and security. In this research, the metallic foil explosion using high current is paid my attention to the method to obtain linear or planate explosive initiation easily, and the main evaluation of metallic foil explosion was conducted. The explosion power was evaluated by observing optically the underwater shock wave generated from the metallic foil explosion.

  20. Pentaerythritol tetranitrate (PETN) profiling in post-explosion residues to constitute evidence of crime-scene presence.

    PubMed

    Brust, Hanneke; van Asten, Arian; Koeberg, Mattijs; van der Heijden, Antoine; Kuijpers, Chris-Jan; Schoenmakers, Peter

    2013-07-10

    Pentaerythritol tetranitrate (PETN) and its degradation products are analyzed to discriminate between residues originating from PETN explosions and residues obtained under other circumstances, such as natural degradation on textile, or after handling intact PETN. The degradation products observed in post-explosion samples were identified using liquid chromatography-mass spectrometry as the less-nitrated analogues of PETN: pentaerythritol trinitrate (PETriN), pentaerythritol dinitrate (PEDiN) and pentaerythritol mononitrate (PEMN). Significant levels of these degradation products were observed in post-explosion samples, whereas only very low levels were detected in a variety of intact PETN samples and naturally degraded PETN. No significant degradation was observed after 12 weeks of storage at room temperature and the influence of high relative humidity (90%) was found to be small. Natural degradation was accelerated by storage of small amounts of PETN on different types of textile, resembling the clothing of a suspect, at elevated temperature (333K). This resulted in significant levels of PETN degradation products, but the relative amounts remained much lower than in post-explosion PETN. For PETriN the peak area relative to PETN was 0.014 (SD=0.0051) and 0.39 (SD=0.19) respectively. Based on the peak areas of PETriN, PEDiN and PEMN relative to PETN, it was possible to fully distinguish the post-explosion profiles from the profiles obtained from intact PETN or after (accelerated) natural degradation. Although more data are required to accurately assess the strength of the evidence, this work illustrates that PETN profiling may yield valuable evidence when investigating a possible link between a suspect and post-explosion PETN found on a crime scene. Due to the substantial variation in the degradation pattern between explosion experiments and even between sampling positions in one experiment, the method is not able to distinguish different PETN explosion events. PMID

  1. Criticality safety in high explosives dissolution

    SciTech Connect

    Troyer, S.D.

    1997-06-01

    In 1992, an incident occurred at the Pantex Plant in which the cladding around a fissile material component (pit) cracked during dismantlement of the high explosives portion of a nuclear weapon. Although the event did not result in any significant contamination or personnel exposures, concerns about the incident led to the conclusion that the current dismantlement process was unacceptable. Options considered for redesign, dissolution tooling design considerations, dissolution tooling design features, and the analysis of the new dissolution tooling are summarized. The final tooling design developed incorporated a number of safety features and provides a simple, self-contained, low-maintenance method of high explosives removal for nuclear explosive dismantlement. Analyses demonstrate that the tooling design will remain subcritical under normal, abnormal, and credible accident scenarios. 1 fig.

  2. Fingerprinting postblast explosive residues by portable capillary electrophoresis with contactless conductivity detection.

    PubMed

    Kobrin, Eeva-Gerda; Lees, Heidi; Fomitšenko, Maria; Kubáň, Petr; Kaljurand, Mihkel

    2014-04-01

    A portable capillary electrophoretic system with contactless conductivity detection was used for fingerprint analysis of postblast explosive residues from commercial organic and improvised inorganic explosives on various surfaces (sand, concrete, metal witness plates). Simple extraction methods were developed for each of the surfaces for subsequent simultaneous capillary electrophoretic analysis of anions and cations. Dual-opposite end injection principle was used for fast (<4 min) separation of 10 common anions and cations from postblast residues using an optimized separation electrolyte composed of 20 mM MES, 20 mM l-histidine, 30 μM CTAB and 2 mM 18-crown-6. The concentrations of all ions obtained from the electropherograms were subjected to principal component analysis to classify the tested explosives on all tested surfaces, resulting in distinct cluster formations that could be used to verify (each) type of the explosive. PMID:24375169

  3. Securing Infrastructure from High Explosive Threats

    SciTech Connect

    Glascoe, L; Noble, C; Reynolds, J; Kuhl, A; Morris, J

    2009-03-20

    Lawrence Livermore National Laboratory (LLNL) is working with the Department of Homeland Security's Science and Technology Directorate, the Transportation Security Administration, and several infrastructure partners to characterize and help mitigate principal structural vulnerabilities to explosive threats. Given the importance of infrastructure to the nation's security and economy, there is a clear need for applied research and analyses (1) to improve understanding of the vulnerabilities of these systems to explosive threats and (2) to provide decision makers with time-critical technical assistance concerning countermeasure and mitigation options. Fully-coupled high performance calculations of structural response to ideal and non-ideal explosives help bound and quantify specific critical vulnerabilities, and help identify possible corrective schemes. Experimental validation of modeling approaches and methodologies builds confidence in the prediction, while advanced stochastic techniques allow for optimal use of scarce computational resources to efficiently provide infrastructure owners and decision makers with timely analyses.

  4. REVIEW: Application of laser photothermal spectroscopy for standoff detection of trace explosive residues on surfaces

    NASA Astrophysics Data System (ADS)

    Skvortsov, L. A.; Maksimov, E. M.

    2010-09-01

    Laser photothermal methods of standoff detection of trace explosive residues on surfaces are considered. The analysis is restricted to the most promising methods: photoacoustic spectroscopy, deflection spectroscopy, and IR photothermal imaging of objects under resonant irradiation. Particular attention is paid to the choice of radiation sources and detectors. Comparative analysis of the existing standoff detection methods for explosive particles on the object surface is performed. Prospects of laser photothermal spectroscopy in this field are discussed.

  5. Application of laser photothermal spectroscopy for standoff detection of trace explosive residues on surfaces

    SciTech Connect

    Skvortsov, L A; Maksimov, E M

    2010-09-10

    Laser photothermal methods of standoff detection of trace explosive residues on surfaces are considered. The analysis is restricted to the most promising methods: photoacoustic spectroscopy, deflection spectroscopy, and IR photothermal imaging of objects under resonant irradiation. Particular attention is paid to the choice of radiation sources and detectors. Comparative analysis of the existing standoff detection methods for explosive particles on the object surface is performed. Prospects of laser photothermal spectroscopy in this field are discussed. (review)

  6. Polymer blends as high explosive binders

    SciTech Connect

    Hoffman, D.M.; Caley, L.E.

    1984-10-05

    One approach to high-density, high-modulus binders for explosives is to blend low-density, high-modulus polymers with high-density, low-modulus polymers. Improved properties, which miscible pairs theoretically should have, are discussed. Two attempts to achieve miscibility between a high-density fluoropolymer (Kel-F 800) and high-modulus thermoplastics (Lucite 130 and Phenoxy PKHJ) were unsuccessful. These blends are immiscible and their physical properties are additive or not significantly enhanced. Anelastic properties of the blends indicate phase separation by the presence of two glass transitions, one associated with each phase. Unfortunately, neither of these pairs has merit as an improved plastic-bonded explosive binder. However, a compatible (miscible) pair would be an improved binder if the appropriate polymer pair could be found.

  7. Residual stresses in a stainless steel - titanium alloy joint made with the explosive technique

    NASA Astrophysics Data System (ADS)

    Taran, Yu V.; Balagurov, A. M.; Sabirov, B. M.; Evans, A.; Davydov, V.; Venter, A. M.

    2012-02-01

    Joining of pipes from stainless steel (SS) and titanium (Ti) alloy still experience serious technical problems. Recently, reliable and hermetic joining of SS and Ti pipes has been achieved with the explosive bonding technique in the Russian Federal Nuclear Center. Such adapters are earmarked for use at the future International Linear Collider. The manufactured SS-Ti adapters have excellent mechanical behavior at room and liquid nitrogen temperatures, during high-pressure tests and thermal cycling. We here report the first neutron diffraction investigation of the residual stresses in a SS-Ti adapter on the POLDI instrument at the SINQ spallation source. The strain scanning across the adapter walls into the SS-SS and SS-Ti pipes sections encompassed measurement of the axial, radial and hoop strain components, which were transformed into residual stresses. The full stress information was successfully determined for the three steel pipes involved in the joint. The residual stresses do not exceed 300 MPa in magnitude. All stress components have tensile values close to the adapter internal surface, whilst they are compressive close to the outer surface. The strong incoherent and weak coherent neutron scattering cross-sections of Ti did not allow for the reliable determination of stresses inside the titanic pipe.

  8. Detection of explosives and latent fingerprint residues utilizing laser pointer-based Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Malka, Itamar; Petrushansky, Alona; Rosenwaks, Salman; Bar, Ilana

    2013-12-01

    A modular, compact Raman spectrometer, based on a green laser pointer, an air cooled intensified charged coupled device and a x, y motorized translation stage was developed and applied for point detection. Its performance was tested for measurements of Raman spectra of liquids, trace amounts of explosives and individual particles, as well as for locating individual particles of interest and for chemical imaging of residues of latent human fingerprints. This system was found to be highly sensitive, identifying masses as low as ~1 ng in short times. The point and real-time detection capabilities of the spectrometer, together with the portability that it offers, make it a potential candidate for replacing existing Raman microscopes and for field applications.

  9. Collection of trace evidence of explosive residues from the skin in a death due to a disguised letter bomb. The synergy between confocal laser scanning microscope and inductively coupled plasma atomic emission spectrometer analyses.

    PubMed

    Turillazzi, Emanuela; Monaci, Fabrizio; Neri, Margherita; Pomara, Cristoforo; Riezzo, Irene; Baroni, Davide; Fineschi, Vittorio

    2010-04-15

    In most deaths caused by explosive, the victim's body becomes a depot for fragments of explosive materials, so contributing to the collection of trace evidence which may provide clues about the specific type of device used with explosion. Improvised explosive devices are used which contain "homemade" explosives rather than high explosives because of the relative ease with which such components can be procured. Many methods such as chromatography-mass spectrometry, scanning electron microscopy, stereomicroscopy, capillary electrophoresis are available for use in the identification of explosive residues on objects and bomb fragments. Identification and reconstruction of the distribution of explosive residues on the decedent's body may give additional hints in assessing the position of the victim in relation to the device. Traditionally these residues are retrieved by swabbing the body and clothing during the early phase, at autopsy. Gas chromatography-mass spectrometry and other analytical methods may be used to analyze the material swabbed from the victim body. The histological examination of explosive residues on skin samples collected during the autopsy may reveal significant details. The information about type, quantity and particularly about anatomical distribution of explosive residues obtained utilizing confocal laser scanning microscope (CLSM) together with inductively coupled plasma atomic emission spectrometer (ICP-AES), may provide very significant evidence in the clarification and reconstruction of the explosive-related events. PMID:20047806

  10. Computed tomography experiments of Pantex high explosives

    NASA Astrophysics Data System (ADS)

    Perkins, D. E.; Martz, H. E.; Hester, L. O.; Sobczak, G.; Pratt, C. L.

    1992-04-01

    X-ray computed tomography is an advanced imaging technique which provide three-dimensional nondestructive characterization of materials, components and assemblies. The CT Project group at Lawrence Livermore National Laboratory (LLNL) and the Pantex Plant are cooperating to examine the use of CT technology to inspect and characterize high-explosives pressings (e.g., PBX-9502, LX-10-2). High-explosives pressings manufactured by Pantex must be characterized prior to assembling into weapons systems; a nondestructive examination of all assembly parts would be preferable to the current sampling and destructive testing. The earlier in the processing cycle this can be done the more cost effective it will be. We have performed experiments that show that this characterization can be performed at the pressed billet stage using CT. We have detected 2-mm inclusions in a 15-cm diameter billet and 3.5-mm voids in a 20-cm diameter billet. Based on these results we show calculations that can be used to design production CT systems for characterization of high-explosives.

  11. Desorption of nitramine and nitroaromatic explosive residues from soils detonated under controlled conditions.

    PubMed

    Douglas, Thomas A; Walsh, Marianne E; McGrath, Christian J; Weiss, Charles A; Jaramillo, Ashley Marie; Trainor, Thomas P

    2011-02-01

    Potentially toxic nitroaromatic and nitramine compounds are introduced onto soils during detonation of explosives. The present study was conducted to investigate the desorption and transformation of explosive compounds loaded onto three soils through controlled detonation. The soils were proximally detonated with Composition B, a commonly used military explosive containing 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro 1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). Gas-exchangeable surface areas were measured from pristine and detonated soils. Aqueous batches of detonated soils were prepared by mixing each soil with ultrapure water. Samples were collected for 141 d and concentrations of Composition B compounds and TNT transformation products 2-amino-4,6-dinitrotoluene (2ADNT), 4-amino-2,6-dinitrotoluene (4ADNT), and 1,3,5-trinitrobenzene (1,3,5-TNB) were measured. The RDX, HMX, and TNT concentrations in detonated soil batches exhibited first-order physical desorption for the first, roughly, 10 d and then reached steady state apparent equilibrium within 40 d. An aqueous batch containing powdered Composition B in water was sampled over time to quantify TNT, RDX, and HMX dissolution from undetonated Composition B particles. The TNT, RDX, and HMX concentrations in aqueous batches of pure Composition B reached equilibrium within 6, 11, and 20 d, respectively. Detonated soils exhibited lower gas-exchangeable surface areas than their pristine counterparts. This is likely due to an explosive residue coating on detonated soil surfaces, shock-induced compaction, sintering, and/or partial fusion of soil particles under the intense heat associated with detonation. Our results suggest that explosive compounds loaded to soils through detonation take longer to reach equilibrium concentrations in aqueous batches than soils loaded with explosive residues through aqueous addition. This is likely due to the heterogeneous interactions between

  12. Morphological Variations of Explosive Residue Particles and Implications for Understanding Detonation Mechanisms.

    PubMed

    Abdul-Karim, Nadia; Blackman, Christopher S; Gill, Philip P; Morgan, Ruth M; Matjacic, Lidija; Webb, Roger; Ng, Wing H

    2016-04-01

    The possibility of recovering undetonated explosive residues following detonation events is well-known; however, the morphology and chemical identity of these condensed phase postblast particles remains undetermined. An understanding of the postblast explosive particle morphology would provide vital information during forensic examinations, allowing rapid initial indication of the explosive material to be microscopically determined prior to any chemical analyses and thereby saving time and resources at the crucial stage of an investigation. In this study, condensed phase particles collected from around the detonations of aluminized ammonium nitrate and RDX-based explosive charges were collected in a novel manner utilizing SEM stubs. By incorporating the use of a focused ion beam during analysis, for the first time it is possible to determine that such particles have characteristic shapes, sizes, and internal structures depending on the explosive and the distance from the detonation at which the particles are recovered. Spheroidal particles (10-210 μm) with microsurface features recovered following inorganic charge detonations were dissimilar to the irregularly shaped particles (5-100 μm) recovered following organic charge firings. Confirmatory analysis to conclude that the particles were indeed explosive included HPLC-MS, Raman spectroscopy, and mega-electron volt-secondary ionization mass spectrometry. These results may impact not only forensic investigations but also the theoretical constructs that govern detonation theory by indicating the potential mechanisms by which these particles survive and how they vary between the different explosive types. PMID:26938055

  13. Internal Detonation Velocity Measurements Inside High Explosives

    SciTech Connect

    Benterou, J; Bennett, C V; Cole, G; Hare, D E; May, C; Udd, E

    2009-01-16

    In order to fully calibrate hydrocodes and dynamic chemistry burn models, initiation models and detonation models of high explosives, the ability to continuously measure the detonation velocity within an explosive is required. Progress on an embedded velocity diagnostic using a 125 micron diameter optical fiber containing a chirped fiber Bragg grating is reported. As the chirped fiber Bragg grating is consumed by the moving detonation wave, the physical length of the unconsumed Bragg grating is monitored with a fast InGaAs photodiode. Experimental details of the associated equipment and data in the form of continuous detonation velocity records within PBX-9502 are presented. This small diameter fiber sensor has the potential to measure internal detonation velocities on the order of 10 mm/{micro}sec along path lengths tens of millimeters long.

  14. High pressure-resistant nonincendive emulsion explosive

    DOEpatents

    Ruhe, Thomas C.; Rao, Pilaka P.

    1994-01-01

    An improved emulsion explosive composition including hollow microspheres/bulking agents having high density and high strength. The hollow microspheres/bulking agents have true particle densities of about 0.2 grams per cubic centimeter or greater and include glass, siliceous, ceramic and synthetic resin microspheres, expanded minerals, and mixtures thereof. The preferred weight percentage of hollow microspheres/bulking agents in the composition ranges from 3.0 to 10.0 A chlorinated paraffin oil, also present in the improved emulsion explosive composition, imparts a higher film strength to the oil phase in the emulsion. The emulsion is rendered nonincendive by the production of sodium chloride in situ via the decomposition of sodium nitrate, a chlorinated paraffin oil, and sodium perchlorate. The air-gap sensitivity is improved by the in situ formation of monomethylamine perchlorate from dissolved monomethylamine nitrate and sodium perchlorate. The emulsion explosive composition can withstand static pressures to 139 bars and dynamic pressure loads on the order of 567 bars.

  15. Atmosphere issues in detection of explosives and organic residues

    NASA Astrophysics Data System (ADS)

    Brown, C. G.; Baudelet, M.; Bridge, C.; Fisher, M. K.; Sigman, M.; Dagdigian, P. J.; Richardson, M.

    2009-05-01

    This study makes a comparison of LIBS emission from molecular species in plasmas produced from organic residues on a non-metallic substrate by both a 5 ns Nd:YAG laser (1064 nm) and a 40 fs Ti:Sapphire laser (800 nm) in air and argon atmospheres. The organic samples analyzed had varying amounts of carbon, nitrogen, hydrogen, and oxygen in their molecular structure. The characterization was based on the atomic carbon, hydrogen, nitrogen, and oxygen lines as well as the diatomic species CN (B2Σ+ - X2Σ+) and the C2 (d3Πg - a3Πu). Principal Component Analysis (PCA) was used to identify similarities of the organic analyte via the emission spectra. The corresponding Receiver Operating Characteristics (ROC) curves show the limitations of the PCA model for the nanosecond regime in air.

  16. Standoff Hyperspectral Imaging of Explosives Residues Using Broadly Tunable External Cavity Quantum Cascade Laser Illumination

    SciTech Connect

    Bernacki, Bruce E.; Phillips, Mark C.

    2010-05-01

    We describe experimental results on the detection of explosives residues using active hyperspectral imaging by illumination of the target surface using an external cavity quantum cascade laser (ECQCL) and imaging using a room temperature microbolometer camera. The active hyperspectral imaging technique forms an image hypercube by recording one image for each tuning step of the ECQCL. The resulting hyperspectral image contains the full absorption spectrum produced by the illumination laser at each pixel in the image which can then be used to identify the explosive type and relative quantity using spectral identification approaches developed initially in the remote sensing community.

  17. Determining the effects of routine fingermark detection techniques on the subsequent recovery and analysis of explosive residues on various substrates.

    PubMed

    King, Sam; Benson, Sarah; Kelly, Tamsin; Lennard, Chris

    2013-12-10

    An offender who has recently handled bulk explosives would be expected to deposit latent fingermarks that are contaminated with explosive residues. However, fingermark detection techniques need to be applied in order for these fingermarks to be detected and recorded. Little information is available in terms of how routine fingermark detection methods impact on the subsequent recovery and analysis of any explosive residues that may be present. If an identifiable fingermark is obtained and that fingermark is found to be contaminated with a particular explosive then that may be crucial evidence in a criminal investigation (including acts of terrorism involving improvised explosive devices). The principal aims of this project were to investigate: (i) the typical quantities of explosive material deposited in fingermarks by someone who has recently handled bulk explosives; and (ii) the effects of routine fingermark detection methods on the subsequent recovery and analysis of explosive residues in such fingermarks. Four common substrates were studied: paper, glass, plastic (polyethylene plastic bags), and metal (aluminium foil). The target explosive compounds were 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), as well as chlorate and nitrate ions. Recommendations are provided in terms of the application of fingermark detection methods on surfaces that may contain explosive residues. PMID:24314527

  18. Three Decades of Explosive High Energy Transients

    NASA Technical Reports Server (NTRS)

    Kouveliotou, Chryssa

    2013-01-01

    Gamma-Ray Bursts are the most brilliant explosions in space. The first GRB was discovered on 1967, just 40 years ago. It took several years and multiple generations of space and ground instruments to unravel some of the mysteries of this phenomenon. However, many questions remain open today. I will discuss the history, evolution and current status of the GRB field and its contributions in our understanding of the transient high energy sky. Finally, I will describe how GRBs can be utilized in future missions as tools, to probe the cosmic chemical evolution of the Universe and the star formation rates.

  19. Influence of explosive density on mechanical properties of high manganese steel explosion hardened

    NASA Astrophysics Data System (ADS)

    Hu, Xiaoyan; Shen, Zhaowu; Liu, Yingbin; Liu, Tiansheng; Wang, Fengying

    2013-12-01

    The explosion hardening tests of high manganese steel were carried out by using two kinds of explosives of the same composition but different density, respectively. The detonation velocities were tested and the relevant mechanical properties were studied. The results show that the stronger single impulse acting on the specimen, the more hardness of surface increases and the more impact toughness decreases. Compared with the explosive of 1.48 g/cm3 density, the hardness, elongation rate, and impact toughness of the sample for triple explosion with explosive of 1.38 g/cm3 density are larger at the same hardening depth. In addition, the tensile strength of the sample for triple explosion with density of 1.38 g/cm3 is higher from the surface to 15 mm below the surface hardened.

  20. Determination of nitroaromatic explosives residue at military shooting ranges using a sweeping-MEKC method.

    PubMed

    Yang, Ying-Ying; Liu, Ju-Tsung; Lin, Cheng-Huang

    2009-03-01

    We report on the application of sweeping-MEKC, for the first time, using the Environmental Protection Agency Method 8330 stock standard (a mixture of 14 explosives). The use of a traditional MEKC mode provided the LODs (at S/N=3) ranging from 1.5 to 2.9 microg/mL for the 14 explosives standards, which were improved by as low as 3.1-6.5 ng/mL when a sweeping-MEKC technique was used. A set of 21 soil samples were collected from surface soil at military shooting ranges located at Kinmen County in Taiwan, and the findings showed that hexahydro-1,3,5-trini-tro-1,3,5-triazine and 2,4,6-trinitrotoluene made up the explosives residue present at the highest concentrations. This study is very useful for determining current levels of explosives residue and as a reference for making appropriate recommendations concerning future site characterization techniques. PMID:19229840

  1. Multistage reaction pathways in detonating high explosives

    SciTech Connect

    Li, Ying; Kalia, Rajiv K.; Nakano, Aiichiro; Nomura, Ken-ichi; Vashishta, Priya

    2014-11-17

    Atomistic mechanisms underlying the reaction time and intermediate reaction products of detonating high explosives far from equilibrium have been elusive. This is because detonation is one of the hardest multiscale physics problems, in which diverse length and time scales play important roles. Here, large spatiotemporal-scale reactive molecular dynamics simulations validated by quantum molecular dynamics simulations reveal a two-stage reaction mechanism during the detonation of cyclotrimethylenetrinitramine crystal. Rapid production of N{sub 2} and H{sub 2}O within ∼10 ps is followed by delayed production of CO molecules beyond ns. We found that further decomposition towards the final products is inhibited by the formation of large metastable carbon- and oxygen-rich clusters with fractal geometry. In addition, we found distinct unimolecular and intermolecular reaction pathways, respectively, for the rapid N{sub 2} and H{sub 2}O productions.

  2. Mesoscale modeling of metal-loaded high explosives

    SciTech Connect

    Bdzil, John Bohdan; Lieberthal, Brandon; Srewart, Donald S

    2010-01-01

    We describe a 3D approach to modeling multi-phase blast explosive, which is primarily condensed explosive by volume with inert embedded particles. These embedded particles are uniform in size and placed on the array of a regular lattice. The asymptotic theory of detonation shock dynamics governs the detonation shock propagation in the explosive. Mesoscale hydrodynamic simulations are used to show how the particles are compressed, deformed, and accelerated by the high-speed detonation products flow.

  3. Identification of homemade inorganic explosives by ion chromatographic analysis of post-blast residues.

    PubMed

    Johns, Cameron; Shellie, Robert A; Potter, Oscar G; O'Reilly, John W; Hutchinson, Joseph P; Guijt, Rosanne M; Breadmore, Michael C; Hilder, Emily F; Dicinoski, Greg W; Haddad, Paul R

    2008-02-29

    Anions and cations of interest for the post-blast identification of homemade inorganic explosives were separated and detected by ion chromatographic (IC) methods. The ionic analytes used for identification of explosives in this study comprised 18 anions (acetate, benzoate, bromate, carbonate, chlorate, chloride, chlorite, chromate, cyanate, fluoride, formate, nitrate, nitrite, perchlorate, phosphate, sulfate, thiocyanate and thiosulfate) and 12 cations (ammonium, barium(II), calcium(II), chromium(III), ethylammonium, magnesium(II), manganese(II), methylammonium, potassium(I), sodium(I), strontium(II), and zinc(II)). Two IC separations are presented, using suppressed IC on a Dionex AS20 column with potassium hydroxide as eluent for anions, and non-suppressed IC for cations using a Dionex SCS 1 column with oxalic acid/acetonitrile as eluent. Conductivity detection was used in both cases. Detection limits for anions were in the range 2-27.4ppb, and for cations were in the range 13-115ppb. These methods allowed the explosive residue ions to be identified and separated from background ions likely to be present in the environment. Linearity (over a calibration range of 0.05-50ppm) was evaluated for both methods, with r(2) values ranging from 0.9889 to 1.000. Reproducibility over 10 consecutive injections of a 5ppm standard ranged from 0.01 to 0.22% relative standard deviation (RSD) for retention time and 0.29 to 2.16%RSD for peak area. The anion and cation separations were performed simultaneously by using two Dionex ICS-2000 chromatographs served by a single autoinjector. The efficacy of the developed methods was demonstrated by analysis of residue samples taken from witness plates and soils collected following the controlled detonation of a series of different inorganic homemade explosives. The results obtained were also confirmed by parallel analysis of the same samples by capillary electrophoresis (CE) with excellent agreement being obtained. PMID:18221942

  4. Equation of state of unreacted high explosives at high pressures

    SciTech Connect

    Yoo, C-S

    1998-08-14

    Isotherms of unreacted high explosives (HMX, RDX, and PETN) have been determined to quasi-hydrostatic high pressures below 45 GPa, by using a diamond-anvil cell angle-resolved synchrotron x-ray diffraction method. The equation-of-state parameters (bulk modulus Bo, and its derivatives B' ) are presented for the 3rd-order Birch-Murnaghan formula based on the measured isotherms. The results are also used to retrieve unreacted Hugoniots in these high explosives and to develop the equations of state and kinetic models for composite high explolsivcs such as XTX-8003 and LX-04. The evidence of shear-induced chemistry of HMX in non-hydrostatic conditions is also presented.

  5. Energetic nanocomposites for detonation initiation in high explosives without primary explosives

    NASA Astrophysics Data System (ADS)

    Comet, Marc; Martin, Cédric; Klaumünzer, Martin; Schnell, Fabien; Spitzer, Denis

    2015-12-01

    The mixing of aluminum nanoparticles with a metal containing oxidizer (here, WO3 or Bi2(SO4)3) gives reactive materials called nanothermites. In this research, nanothermites were combined with high explosive nanoparticles (RDX) to prepare energetic nanocomposites. These smart nanomaterials have higher performances and are much less hazardous than primary explosives. Their flame propagation velocity can be tuned from 0.2 to 3.5 km/s, through their explosive content. They were used to initiate the detonation of a high explosive, the pentaerythritol tetranitrate. The pyrotechnic transduction of combustion into detonation was achieved with short length systems (<2 cm) and small amounts of energetic nanocomposites (˜100 mg) in semi-confined systems.

  6. Mechanisms of laser-induced photocatalytic decomposition of high explosives

    NASA Astrophysics Data System (ADS)

    Mitrofanov, Anatoly; Zverev, Anton; Rashkeev, Sergey; Tsyshevsky, Roman; Kuklja, Maija

    Using laser irradiation for triggering explosive decomposition of high density energy materials opens up new opportunities in design of safe optical detonators by removing primary explosive from the devices. Precise tuning of sensitivity to initiation of detonation via photo-excitation appears challenging because all secondary explosives are insulators with the band gap of 4-8 eV. We will discuss our combined experimental and theoretical studies that suggest feasible mechanisms of photocatalytic decomposition of explosives triggered by the laser excitation with the energy of 1.17 - 2.3 eV and the wavelength of 1064-532 nm. The first approach considers tuning the optical absorption via the controlled modification of the electronic structure of the explosive-metal oxide interfaces. The second approach involves incorporating photoactive organic molecules in the crystalline matrix of the explosive material.

  7. Behavior of Plastic Bonded Composite Explosives During High Acceleration

    NASA Astrophysics Data System (ADS)

    Lanzerotti, Y.

    1998-03-01

    The mechanical behavior of plastic bonded composite explosives has been studied during high acceleration in an ultracentrifuge. The pressed explosives studied include LX-14 [95% HMX (cyclotetramethylene- tetranitramine), 5% Estane], Composition A3 type II [91% RDX (cyclotrimethylene-trinitramine), 99% BDNPF (bis-dinitropropyl acetal formal), 6% CAB (cellulose acetate butyrate)], and PAX-3 (85% HMX, 9% BDNPF, 6% CAB/25% Aluminum). The fracture strength of LX-14 is greater than all pressed explosives studied to date. The fracture strength of Composition A3 type II is smaller than all pressed explosives studied to date.

  8. Contained high explosive firing facility (CHEFF)

    SciTech Connect

    Stacy, H.L.; Seitz, W.L.; Wackerle, J.; Polcyn, M.; Esparza, E.

    1993-08-01

    A cylindrical vessel capable of totally containing the products and shrapnel resulting from the detonation of 10 kg of TNT (or equivalent) has been designed and built by Southwest Research Institute for and according to the requirements of the Detonation Systems Group (M-7) of Los Alamos National Laboratory. The vessel is 6.0-m long by 3.6-m diameter and is manufactured of 50-mm (elliptical end caps) and 38-mm (cylindrical walls) thick high-strength steel (HY-100). The cylindrical walls of the vessel are lined with 13-mm thick replaceable steel plates for shrapnel protection. The floor is made of steel-covered concrete. Ten large-aperture (254 mm) optical ports are available for instrumentation and four ports are provided for cabling and plumbing. Two qualifying detonation tests of 8.8 kg of C-4 explosive (equivalent to 10 kg TNT) have shown that the maximum strain produced is less than 78% of the elastic limit. The vessel is installed in a converted outdoor firing facility that has been modified to include an insulated and heated metal building to house the vessel and additional instrumentation. A computer-based system for data acquisition, firing control, and the monitoring of vessel response is described.

  9. Multistage reaction pathways in detonating high explosives

    NASA Astrophysics Data System (ADS)

    Li, Ying; Kalia, Rajiv; Nakano, Aiichiro; Vashishta, Priya; CACS Collaboration; ALCF Team

    2015-06-01

    Atomistic mechanisms underlying the reaction time and intermediate reaction products of detonating high explosives far from equilibrium have been elusive. This is because detonation is one of the hardest multiscale physics problems, in which diverse length and time scales play important roles. Here, large spatiotemporal-scale reactive molecular dynamics simulations validated by quantum molecular dynamics simulations reveal a two-stage reaction mechanism during the detonation of cyclotrimethylenetrinitramine crystal. Rapid production of N2 and H2O within 10 ps is followed by delayed production of CO molecules beyond ns. We found that further decomposition towards the final products is inhibited by the formation of large metastable carbon- and oxygen-rich clusters with fractal geometry. In addition, we found distinct uni-molecular and intermolecular reaction pathways, respectively, for the rapid N2 and H2O productions. This work was supported by the Office of Naval Research Grant No. N000014-12-1-0555 and the Basic Research Program of Defense Threat Reduction Agency (DTRA) Grant No. HDTRA1-08-1-0036. All the simulations were performed at USC and Argonne LCF.

  10. Investigation Of Vapor Explosion Mechanisms Using High Speed Photography

    NASA Astrophysics Data System (ADS)

    Armstrong, Donn R.; Anderson, Richard P.

    1983-03-01

    The vapor explosion, a physical interaction between hot and cold liquids that causes the explosive vaporization of the cold liquid, is a hazard of concern in such diverse industries as metal smelting and casting, paper manufacture, and nuclear power generation. Intensive work on this problem worldwide, for the past 25 years has generated a number of theories and mechanisms proposed to explain vapor explosions. High speed photography has been the major instrument used to test the validity of the theories and to provide the observations that have lead to new theories. Examples are given of experimental techniques that have been used to investigate vapor explosions. Detailed studies of specific mechanisms have included microsecond flash photograph of contact boiling and high speed cinematography of shock driven breakup of liquid drops. Other studies looked at the explosivity of various liquid pairs using cinematography inside a pulsed nuclear reactor and x-ray cinematography of a thermite-sodium interaction.

  11. Turbulent mixing in high-altitude explosions

    SciTech Connect

    Kuhl, A.L.; Bell, J.B. ); Ferguson, R.E. ); White, W.W.; McCartor, T.H. )

    1992-09-01

    Numerical simulations of a high-altitude explosion were performed using a Godunov code with Adaptive Mesh Refinement (AMR). The code solves the two-dimensional (2-D), time-dependent conservation laws of inviscid gas dynamics while AMR is used to focus the computational effort in the mixing regions. The calculations revealed that a spherical density interface embedded in this flow was unstable and rolled up into a turbulent mixing layer. The shape of the interface was qualitatively similar to experimental photographs. Initially, the mixing layer width grew as a linear function of time, but eventually it reached an asymptotically-constant value. The flow field was azimuthally-averaged to evaluate the mean-flow profiles and the R.M.S. fluctuation profiles across the mixing layer. The mean kinetic energy rapidly approached zero as the blast wave decayed, but the fluctuating kinetic energy asymptotically approached a small constant value (a fraction of a percent of the maximum kinetic energy). This represents the rotational kinetic energy driven by the vorticity field, that continued to mix the fluid indefinitely. It was shown that the vorticity field corresponds to a function that fluctuates between plus and minus values -- with a volume-averaged mean of zero. The amplitude of the vorticity fluctuations decayed as t[sup [minus]1]. The corresponding enstrophy increased linearly with time because of a cascade process for the mean-squared vorticity. This result is in good agreement with the 2-D calculations of turbulent flow as reported by G.K. Batchelor. The problem should be recalculated in 3-D to study the decay of turbulent mixing for spherical interfaces.

  12. Turbulent mixing in high-altitude explosions

    SciTech Connect

    Kuhl, A.L.; Bell, J.B.; Ferguson, R.E.; White, W.W.; McCartor, T.H.

    1992-09-01

    Numerical simulations of a high-altitude explosion were performed using a Godunov code with Adaptive Mesh Refinement (AMR). The code solves the two-dimensional (2-D), time-dependent conservation laws of inviscid gas dynamics while AMR is used to focus the computational effort in the mixing regions. The calculations revealed that a spherical density interface embedded in this flow was unstable and rolled up into a turbulent mixing layer. The shape of the interface was qualitatively similar to experimental photographs. Initially, the mixing layer width grew as a linear function of time, but eventually it reached an asymptotically-constant value. The flow field was azimuthally-averaged to evaluate the mean-flow profiles and the R.M.S. fluctuation profiles across the mixing layer. The mean kinetic energy rapidly approached zero as the blast wave decayed, but the fluctuating kinetic energy asymptotically approached a small constant value (a fraction of a percent of the maximum kinetic energy). This represents the rotational kinetic energy driven by the vorticity field, that continued to mix the fluid indefinitely. It was shown that the vorticity field corresponds to a function that fluctuates between plus and minus values -- with a volume-averaged mean of zero. The amplitude of the vorticity fluctuations decayed as t{sup {minus}1}. The corresponding enstrophy increased linearly with time because of a cascade process for the mean-squared vorticity. This result is in good agreement with the 2-D calculations of turbulent flow as reported by G.K. Batchelor. The problem should be recalculated in 3-D to study the decay of turbulent mixing for spherical interfaces.

  13. Flying-plate detonator using a high-density high explosive

    DOEpatents

    Stroud, John R.; Ornellas, Donald L.

    1988-01-01

    A flying-plate detonator containing a high-density high explosive such as benzotrifuroxan (BTF). The detonator involves the electrical explosion of a thin metal foil which punches out a flyer from a layer overlying the foil, and the flyer striking a high-density explosive pellet of BTF, which is more thermally stable than the conventional detonator using pentaerythritol tetranitrate (PETN).

  14. Passive Infrared Hyperspectral Imaging for Standoff Detection of Tetryl Explosive Residue on a Steel Surface

    SciTech Connect

    Gallagher, Neal B.; Kelly, James F.; Blake, Thomas A.

    2010-06-15

    A commercial imaging FTIR spectrometer that operates between 850 and 1300 cm{sup -1} was used to passively image a galvanized steel plate stained with a residue of the explosive tetryl (2,4,6,N-tetranitro-N-methylaniline). The tetryl was coated onto the plate in a 30 cm diameter spot with an areal dosage of 90 {mu}g tetryl/cm{sup 2}. The stain on the plate was easily detected at standoff distances of 14 and 31 m by examining the hyperspectral data cubes using maximum autocorrelation factors and a slight modification to a generalized least squares target detection algorithm. End-member extraction showed good comparison in a few key bands between the target end-member and laboratory reflectance spectra; however, significant differences were also observed

  15. Method for enhancing stability of high explosives, for purposes of transport or storage, and the stabilized high explosives

    DOEpatents

    Nutt, Gerald L.

    1991-01-01

    The stability of porous solid high explosives, for purposes of transport or storage, is enhanced by reducing the sensitivity to shock initiation of a reaction that leads to detonation. The pores of the explosive down to a certain size are filled under pressure with a stable, low melt temperature material in liquid form, and the combined material is cooled so the pore filling material solidifies. The stability can be increased to progressively higher levels by filling smaller pores. The pore filling material can be removed, at least partially, by reheating above its melt temperature and drained off so that the explosive is once more suitable for detonation.

  16. Acoustic analysis of explosions in high noise environment

    NASA Astrophysics Data System (ADS)

    Man, Hong; Desai, Sachi

    2008-04-01

    Explosion detection and recognition is a critical capability to provide situational awareness to the war-fighters in battlefield. Acoustic sensors are frequently deployed to detect such events and to trigger more expensive sensing/sensor modalities (i.e. radar, laser spectroscope, IR etc.). Acoustic analysis of explosions has been intensively studied to reliably discriminate mortars, artillery, round variations, and type of blast (i.e. chemical/biological or high-explosive). One of the major challenges is high level of noise, which may include non-coherent noise generated from the environmental background and coherent noise induced by possible mobile acoustic sensor platform. In this work, we introduce a new acoustic scene analysis method to effectively enhance explosion classification reliability and reduce the false alarm rate at low SNR and with high coherent noise. The proposed method is based on acoustic signature modeling using Hidden Markov Models (HMMs). Special frequency domain acoustic features characterizing explosions as well as coherent noise are extracted from each signal segment, which forms an observation vector for HMM training and test. Classification is based on a unique model similarity measure between the HMM estimated from the test observations and the trained HMMs. Experimental tests are based on the acoustic explosion dataset from US ARMY ARDEC, and experimental results have demonstrated the effectiveness of the proposed method.

  17. Design of a hypersonic waterjet apparatus driven by high explosives

    SciTech Connect

    Weeks, Brandon L.; Klosterman, John; Worsey, Paul N.

    2001-08-01

    The design and construction of a hypersonic waterjet apparatus is described. Jet velocities from 0.5 to 5 km/s have been achieved using a high explosive charge. Images are obtained in situ on various target substrates using a high-speed framing camera. Experimental results are shown for the impact of high velocity waterjets on propellants and high explosive samples. By observing the impact of the waterjet at a wide range of velocities a safety threshold can be determined where no reaction takes place.

  18. Radio frequency overview of the high explosive radio telemetry project

    SciTech Connect

    Bracht, R.; Dimsdle, J.; Rich, D.; Smith, F.

    1998-12-31

    High explosive radio telemetry (HERT) is a project that is being developed jointly by Los Alamos National Laboratory and AlliedSignal Federal Manufacturing and Technologies. The ultimate goal is to develop a small, modular telemetry system capable of high-speed detection of explosive events, with an accuracy on the order of 10 nanoseconds. The reliable telemetry of this data, from a high-speed missile trajectory, is a very challenging opportunity. All captured data must be transmitted in less than 20 microseconds of time duration. This requires a high bits/Hertz microwave telemetry modulation code to insure transmission of the data with the limited time interval available.

  19. An Orientation to Explosive Safety.

    ERIC Educational Resources Information Center

    Harris, Betty W.

    1987-01-01

    Provides an overview of various types of explosives. Classifies and describes explosives as initiating or primary explosives, low explosives, and high (secondary explosives). Discusses detonating devices, domestic explosive systems, the sensitivity of explosives, explosive reactions, and emergency responses. (TW)

  20. High-explosive-driven delay line pulse generator

    SciTech Connect

    Shearer, J.W.

    1982-11-15

    The inclusion of a delay line circuit into the design of a high-explosive-driven generator shortens the time constant of the output pulse. After a brief review of generator concepts and previously described pulse-shortening methods, a geometry is presented which incorporates delay line circuit techcniques into a coil generator. The circuit constants are adjusted to match the velocity of the generated electromagnetic wave to the detonation velocity of the high explosive. The proposed generator can be modeled by adding a variable inductance term to the telegrapher's equation. A particular solution of this equation is useful for exploring the operational parameters of the generator. The duration of the electromagnetic pulse equals the radial expansion time of the high-explosive-driven armature until it strikes the coil. Because the impedance of the generator is a constant, the current multiplication factor is limited only by nonlinear effects such as voltage breakdown, diffusion, and compression at high energies.

  1. Tool force evaluation of lathe machined high explosives

    SciTech Connect

    Flowers, G.L.

    1980-04-01

    The purpose of this study was to develop a better understanding of the effects of machining properties upon tool forces encountered during lathe machining of high explosives, in order to optimize machining conditions for mechanical properties test specimens. Monetary considerations dictated that the tooling either already exist or be fabricated in-house using limited machine shop capability. The design chosen which fit between the tool holder and the tool post and interfaced to existing signal conditioners was easily fabricated. The study evaluated all forces on the cutter during machining of two types of high explosives at four cutter radii, four feed rates, three depths of cut and two cutting speeds. The study pointed out design problems, instrumentation drift, tool chatter and detection levels. It also showed that the type of high explosive was more significant than first thought toward influencing tool force levels.

  2. Are amino groups advantageous to insensitive high explosives (IHEs)?

    PubMed

    Cao, Xia; Wen, Yushi; Xiang, Bin; Long, Xinping; Zhang, Chaoyang

    2012-10-01

    There is usually a contradiction between increasing energy densities and reducing sensitivities of explosives. The explosives with both high energy densities and low sensitivities, or the so-called insensitive high explosives (IHEs), are desirable in most cases. It seems from applied explosives that amino groups are advantageous to IHE but the amount of amino groups contained IHEs is very limited. To make this clear, we present systemic examinations of the effects on the two properties stressed in IHEs after introducing amino groups to different molecular skeletons. As a result, the amino groups on resonant sites to nitro groups in conjugated systems can improve distinctly sensitivities and change energy densities in terms of oxygen balance; while the amino groups in unconjugated systems can hardly increase energy densities and usually cause increased sensitivities. It agrees well with a fact that almost all the molecules of applied amino group contained explosives possess conjugated skeletons. We therefore confirm that if amino groups are introduced resonantly to a nitro group in a conjugated system and the introduction improves OB, they are advantageous to IHEs. PMID:22660963

  3. High-Energy Processing of Materials Using Explosives

    NASA Astrophysics Data System (ADS)

    Ribeiro, J. B.; Mendes, R. L.; Farinha, A. R.; Plaksin, I. Ye.; Campos, J. A.; Góis, J. C.

    2009-12-01

    The overall field of application of the explosives substances for material processing and synthesis include: Cladding/welding of dissimilar materials; the compaction/consolidation of nanocrystalline, super-hard, high-Tc superconducting composites, metastable highly-alloyed or amorphous powdered materials; the forming of small-series of very special shape and/or very special materials plates; the cutting of metal and/or concrete structures and the synthesis of nanocrystalline, ultra-dispersed, spherical shaped, single component or multicomponent (binary and/or ternary) metal oxide particles. Pretending to be a contribution for the widespread use of explosives for material processing, this paper depicted the particular cases of the explosive welding and consolidation, presenting examples of the research activity developed recently in the Department of Mechanical Engineering of the University of Coimbra.

  4. Inkjet-printed silver nanoparticle paper detects airborne species from crystalline explosives and their ultratrace residues in open environment.

    PubMed

    Wang, Jianping; Yang, Liang; Liu, Bianhua; Jiang, Haihe; Liu, Renyong; Yang, Jingwei; Han, Guangmei; Mei, Qingsong; Zhang, Zhongping

    2014-04-01

    An electronic nose can detect highly volatile chemicals in foods, drugs, and environments, but it is still very much a challenge to detect the odors from crystalline compounds (e.g., solid explosives) with a low vapor pressure using the present chemosensing techniques in such way as a dog's olfactory system can do. Here, we inkjet printed silver nanoparticles (AgNPs) on cellulose paper and established a Raman spectroscopic approach to detect the odors of explosive trinitrotoluene (TNT) crystals and residues in the open environment. The layer-by-layer printed AgNP paper was modified with p-aminobenzenethiol (PABT) for efficiently collecting airborne TNT via a charge-transfer reaction and for greatly enhancing the Raman scattering of PABT by multiple spectral resonances. Thus, a Raman switch concept by the Raman readout of PABT for the detection of TNT was proposed. The AgNPs paper at different sites exhibited a highly uniform sensitivity to TNT due to the layer-by-layer printing, and the sensitive limit could reach 1.6 × 10(-17) g/cm(2) TNT. Experimentally, upon applying a beam of near-infrared low-energy laser to slightly heat (but not destruct) TNT crystals, the resulting airborne TNT in the open environment was probed at the height of 5 cm, in which the concentration of airborne species was lower than 10 ppt by a theoretical analysis. Similarly, the odors from 1.4 ppm TNT in soil and 7.2, 2.9, and 5.7 ng/cm(2) TNT on clothing, leather, and envelope, respectively, were also quickly sensed for 2 s without destoying these inspected objects. PMID:24605843

  5. Optimization of biological and instrumental detection of explosives and ignitable liquid residues including canines, SPME/ITMS and GC/MSn

    NASA Astrophysics Data System (ADS)

    Furton, Kenneth G.; Harper, Ross J.; Perr, Jeannette M.; Almirall, Jose R.

    2003-09-01

    A comprehensive study and comparison is underway using biological detectors and instrumental methods for the rapid detection of ignitable liquid residues (ILR) and high explosives. Headspace solid phase microextraction (SPME) has been demonstrated to be an effective sampling method helping to identify active odor signature chemicals used by detector dogs to locate forensic specimens as well as a rapid pre-concentration technique prior to instrumental detection. Common ignitable liquids and common military and industrial explosives have been studied including trinitrotoluene, tetryl, RDX, HMX, EGDN, PETN and nitroglycerine. This study focuses on identifying volatile odor signature chemicals present, which can be used to enhance the level and reliability of detection of ILR and explosives by canines and instrumental methods. While most instrumental methods currently in use focus on particles and on parent organic compounds, which are often involatile, characteristic volatile organics are generally also present and can be exploited to enhance detection particularly for well-concealed devices. Specific examples include the volatile odor chemicals 2-ethyl-1-hexanol and cyclohexanone, which are readily available in the headspace of the high explosive composition C-4; whereas, the active chemical cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) is not. The analysis and identification of these headspace 'fingerprint' organics is followed by double-blind dog trials of the individual components using certified teams in an attempt to isolate and understand the target compounds to which dogs are sensitive. Studies to compare commonly used training aids with the actual target explosive have also been undertaken to determine their suitability and effectiveness. The optimization of solid phase microextraction (SPME) combined with ion trap mobility spectrometry (ITMS) and gas chromatography/mass spectrometry/mass spectrometry (GC/MSn) is detailed including interface development

  6. Equations of State and High-Pressure Phases of Explosives

    NASA Astrophysics Data System (ADS)

    Peiris, Suhithi M.; Gump, Jared C.

    Energetic materials, being the collective name for explosives, propellants, pyrotechnics, and other flash-bang materials, span a wide range of composite chemical formulations. Most militarily used energetics are solids composed of particles of the pure energetic material held together by a binder. Commonly used binders include various oils, waxes, and polymers or plasticizers, and the composite is melt cast, cured, or pressed to achieve the necessary mechanical properties (gels, putties, sheets, solid blocks, etc.) of the final energetic material. Mining, demolition, and other industries use liquid energetics that are similarly composed of an actual energetic material or oxidizer together with a fuel, that is to be mixed and poured for detonation. Pure energetic materials that are commonly used are nitroglycerine, ammonium nitrate, ammonium or sodium perchlorate, trinitrotoluene (TNT), HMX, RDX, and TATB. All of them are molecular materials or molecular ions that when initiated or insulted undergoes rapid decomposition with excessive liberation of heat resulting in the formation of stable final products. When the final products are gases, and they are rapidly produced, the sudden pressure increase creates a shock wave. When decomposition is so rapid that the reaction moves through the explosive faster than the speed of sound in the unreacted explosive, the material is said to detonate. Typically, energetic materials that undergo detonation are known as high explosives (HEs) and energetic materials that burn rapidly or deflagrate are known as low explosives and/or propellants.

  7. An evaluation of high pressure coal dust explosions

    SciTech Connect

    Dennison, G.; Welford, G.B.; Sage, P.W.

    1995-12-31

    In the United Kingdom an industry-led consortium has been set up to continue the development of a coal-based advanced power generation system. The program primarily addresses the development of the key components for the Air Blown Gasification Cycle (ABGC), previously known as the British Coal Topping Cycle. One of the main features of the ABGC process is the use of an air blown pressurized fluidized bed gasifier which has the advantage over alternative oxygen blown systems, of not requiring air separation equipment. However, as a consequence the ABGC process does not have an available source of nitrogen for purging and pressurizing. Coal in the ABGC process is fed to the gasifier through lock hoppers pressurized up to 25 bar. The storage of coal in air at elevated pressures is associated with an increased propensity for spontaneous heating and dust explosion. This paper describes the experimental work commissioned by the Coal Technology Development Division of British Coal (and undertaken by TNO Prins Maurits Laboratory, Netherlands) to determine the explosive characteristics of a lignite, an anthracite, and a bituminous coal from UK sources over a range of elevated pressures up to 20 bar. Data on the maximum oxygen content, maximum explosion pressure and dust explosion constant are presented. This information will be used to consider the feasibility of alternatives to expensive nitrogen inerting. This will include partial inertization and high pressure dust explosion suppression systems.

  8. Sensitivity of once-shocked, weathered high explosives

    SciTech Connect

    Williams, K.L.; Harris, B.W.

    1998-07-01

    Effects caused by stimulating once-shocked, weathered high explosives (OSW-HE) are investigated. The sensitivity of OSW-HE to mechanical stimuli was determined using standard industry tests. Some initial results are given. Pieces of OSW-HE were collected from active and inactive firing sites and from an area surrounding a drop tower at Los Alamos where skid and spigot tests were done. Samples evaluated were cast explosives or plastic bonded explosive (PBX) formulations containing cyclotrimethylenetrinitramine (RDX), cyclotetramethylene tetranitramine (HMX), 2,4,6-trinitrotoluene (TNT), mock or inert HE [tris(beta-chloroethyl)phosphate (CEF)], barium nitrate, cyanuric acid, talc, and Kel-F. Once-shocked, weathered LX-10 Livermore explosive [HMX/Viton A, (95/5 wt %)], PBX 9011 [HMX/Estane, (90/10 wt %)], PBX 9404 [HMX/nitrocellulose, tris(beta-chloroethyl) phosphate, (94/3/3 wt %)], Composition B or cyclotol (TNT/RDX explosives), and PBX 9007 (90% RDX, 9.1% styrene, 0.5% dioctyl phthalate, and 0.45 resin) were subjected to the hammer test, the drop-weight impact sensitivity test, differential thermal analysis (DTA), the spark test, the Henkin`s critical temperature test, and the flame test. Samples were subjected to remote, wet cutting and drilling; remote, liquid-nitrogen-cooled grinding and crushing; and scanning electron microscope (SEM) surface analyses for morphological changes.

  9. Seismic characteristics of cavity decoupled explosions in limestone: An analysis of Soviet high explosive test data

    NASA Astrophysics Data System (ADS)

    Murphy, J. R.; Kitov, I. O.; Rimer, N.; Adushkin, V. V.; Barker, B. W.

    1997-12-01

    During the summer of 1960, Soviet scientists conducted a series of high-explosive, cavity decoupling tests in a mine in Kirghizia. These decoupled tests were carried out in a variety of mined cavities in limestone, including spherical cavities with diameters ranging from 3.5 to 10 m as well as nonspherical cavities with volumes of about 25 m3. The experiments of this test series consisted of 10 tamped and 12 decoupled explosions having yields of 0.1, 1.0, and 6.0 t, and seismic data were recorded at locations in the mine over a distance range extending from about 10 to 250 m from the sources. These data provide valuable new insight into the dependence of decoupling effectiveness on variables such as cavity volume, cavity shape, and charge emplacement geometry. In particular, analyses indicate that chemical explosions at a depth of 290 m in limestone are essentially fully decoupled in spherical cavities with scaled cavity radii larger than about 27 m/kt⅓ and that the low-frequency decoupling effectiveness under such conditions is approximately independent of cavity shape for roughly cylindrical cavities with length-to-width ratios of as much as 6-12. These results suggest that the possibility of cavity decoupling in nonspherical cavities in hard rock media will have to be carefully evaluated in establishing the seismic verification regime for the Comprehensive Test Ban Treaty.

  10. Establishing a universal swabbing and clean-up protocol for the combined recovery of organic and inorganic explosive residues.

    PubMed

    Song-im, Nopporn; Benson, Sarah; Lennard, Chris

    2012-11-30

    A single-step solvent extraction and a solid-phase extraction (SPE) clean-up procedure was developed and optimised in order to establish a universal sampling and clean-up protocol for the combined recovery of organic and inorganic explosive residues. Mixtures of three common swabbing solvents (acetone, acetonitrile and methanol) with water, in various ratios, were assessed for the extraction of four target organic explosives [pentaerythritol tetranitrate (PETN), 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and triacetone triperoxide (TATP)] and two inorganic anions (chlorate and nitrate) from alcohol wipes that were used as a swabbing medium. An efficient, single-step extraction of both organic and inorganic compounds from the wipes was achieved using 60% v/v methanol/water. To develop a clean-up procedure, four commercially available SPE cartridges (Oasis HLB, Isolute(®) C18, Bond-Elut(®) ENV and ABS ELUT Nexus) and an in-house packed XAD-7 cartridge were firstly evaluated for their retention capacity toward three organic explosives (PETN, TNT and RDX) in a mixture of methanol and water. A SPE technique was then developed and optimised from the short-listed sorbents with four representative organic explosives (including TATP). The Nexus cartridge was found to provide a suitable sorbent for extract clean-up following swab extraction with 60% v/v methanol/water. By incorporating the optimised clean-up procedure with the application of a polyester-based alcohol wipe as a sampling medium, a universal swabbing protocol for the combined recovery of both organic and inorganic explosive residues was established. The feasibility of the proposed protocol was assessed by collection and quantitation of the residue from a mixture of TNT, PETN and chlorate deposited on a laminate test surface. PMID:22959657

  11. High and low velocity detonation in a highly insensitive explosive

    NASA Astrophysics Data System (ADS)

    Sandusky, H. W.; Hayden, H. F.

    2014-05-01

    Low-velocity detonation (LVD) in a solid explosive from input shocks below the threshold for high-velocity detonation (HVD) had been previously reported for PBXN-109 in two gap tests with sample diameters of 36.5 and 73.0 mm. Similar phenomenon has now been observed for the highly insensitive PBXIH-140, whose critical diameter of ~100 mm required an even larger gap test with a sample diameter of 178 mm. When just exceeding the critical gap for HVD, LVD propagated at similar velocities as in PBXN-109 and would punch clean holes in a witness plate like HVD. For somewhat greater gaps, there was enough shock reaction to drive LVD at constant but reduced velocities as the input shock decreased to ~ ½ of critical. With a different formulation now exhibiting LVD, it may be more prevalent than previously realized. It is speculated to occur in various confinements when small percentages of easily detonable ingredients fail to initiate the remainder of less shock sensitive ingredients.

  12. Determination of Nanogram Microparticles from Explosives after Real Open-Air Explosions by Confocal Raman Microscopy.

    PubMed

    Zapata, Félix; García-Ruiz, Carmen

    2016-07-01

    Explosives are increasingly being used for terrorist attacks to cause devastating explosions. The detection of their postblast residues after an explosion is a high challenge, which has been barely investigated, particularly using spectroscopic techniques. In this research, a novel methodology using confocal Raman microscopy has been developed for the analysis of postblast residues from 10 open-air explosions caused by 10 different explosives (TNT, RDX, PETN, TATP, HMTD, dynamite, black powder, ANFO, chloratite, and ammonal) commonly used in improvised explosive devices. The methodology for the determination of postblast particles from explosives consisted of examining the samples surfaces with both the naked eye, first, and microscopically (10× and 50×), immediately afterward; and finally, analyzing the selected residues by confocal Raman spectroscopy in order to identify the postblast particles from explosives. Interestingly, confocal Raman microscopy has demonstrated to be highly suitable to rapidly, selectively, and noninvasively analyze postblast microscopic particles from explosives up to the nanogram range. PMID:27281604

  13. Modeling of high-current devices with explosive electron emission

    NASA Astrophysics Data System (ADS)

    Anishchenko, S. V.; Gurinovich, A. A.

    2014-01-01

    Based on a detailed analysis of explosive electron emission in high-current electronic devices, we formulate a system of equations that describes the expansion of cathode plasma and the generation of high-current electron beams. The system underlies the numerical algorithm for the hybrid code which enables the simulation of the charged particles’ dynamics in high-current vircators with open resonators. Using the Gabor-Morlet transform, we perform a time-frequency analysis of vircator radiation.

  14. Solid-state Forensic Finger sensor for integrated sampling and detection of gunshot residue and explosives: towards 'Lab-on-a-finger'.

    PubMed

    Bandodkar, Amay J; O'Mahony, Aoife M; Ramírez, Julian; Samek, Izabela A; Anderson, Sean M; Windmiller, Joshua R; Wang, Joseph

    2013-09-21

    Increasing security needs require field-deployable, on-the-spot detection tools for the rapid and reliable identification of gunshot residue (GSR) and nitroaromatic explosive compounds. This manuscript presents a simple, all-solid-state, wearable fingertip sensor for the rapid on-site voltammetric screening of GSR and explosive surface residues. To fabricate the new Forensic Fingers, we screen-print a three-electrode setup onto a nitrile finger cot, and coat another finger cot with an ionogel electrolyte layer. The new integrated sampling/detection methodology relies on 'voltammetry of microparticles' (VMP) and involves an initial mechanical transfer of trace amounts of surface-confined analytes directly onto the fingertip-based electrode contingent. Voltammetric measurements of the sample residues are carried out upon bringing the working electrode (printed on the index finger cot) in direct contact with a second finger cot coated with an ionogel electrolyte (worn on the thumb), thus completing the solid-state electrochemical cell. Sampling and screening are performed in less than four minutes and generate distinct voltammetric fingerprints which are specific to both GSR and explosives. The use of the solid, flexible ionogel electrolyte eliminates any liquid handling which can resolve problems associated with leakage, portability and contamination. A detailed study reveals that the fingertip detection system can rapidly identify residues of GSR and nitroaromatic compounds with high specificity, without compromising its attractive behavior even after undergoing repeated mechanical stress. This new integrated sampling/detection fingertip strategy holds considerable promise as a rapid, effective and low-cost approach for on-site crime scene investigations in various forensic scenarios. PMID:23865089

  15. Modeling Hot-Spot Contributions in Shocked High Explosives at the Mesoscale

    SciTech Connect

    Harrier, Danielle

    2015-08-12

    When looking at performance of high explosives, the defects within the explosive become very important. Plastic bonded explosives, or PBXs, contain voids of air and bonder between the particles of explosive material that aid in the ignition of the explosive. These voids collapse in high pressure shock conditions, which leads to the formation of hot spots. Hot spots are localized high temperature and high pressure regions that cause significant changes in the way the explosive material detonates. Previously hot spots have been overlooked with modeling, but now scientists are realizing their importance and new modeling systems that can accurately model hot spots are underway.

  16. High-Energy-Rate Processing of Materials Using Explosives

    NASA Astrophysics Data System (ADS)

    Ribeiro, J.; Mendes, R.; Farinha, R.; Plaksin, I.; Campos, J.; Gois, J.

    2009-06-01

    The overall field of application of explosives substances for material processing and synthesis include: Cladding/welding of dissimilar materials; the compaction/consolidation of nanocrystalline, super-hard, high-Tc superconducting composites, metastable highly-alloyed or amorphous powdered materials; the forming of small-series of very special shape and/or very special materials plates; the cutting of metal and/or concrete structures and the synthesis of nanocrystalline, ultra-dispersed, spherical shaped, single component or multicomponent (binary and/or ternary) metal oxide particles. The very special characteristic features of this technique makes it, sometimes, the only route available to achieve singular results and a promising widespread use can be envisaged for it in a near future. Pretending to contribute for that widespread use, this paper depicted the particular cases of the explosive welding and consolidation, presenting examples of the research activity developed recently at the Department of Mechanical Engineering of the University of Coimbra.

  17. Shock response of the commercial high explosive Detasheet

    NASA Astrophysics Data System (ADS)

    Asay, B. W.; Ramsay, J. B.; Anderson, M. U.; Graham, R. A.

    1994-12-01

    The mechanical and chemical response of the flexible commercial high explosive DetasheetR is studied under controlled impact and plane-wave, high explosive loading. Results on nonreactive material behavior, sound speed, shock-initiation sensitivity and detonation pressure are presented. The material is found to respond in a viscous manner reminiscent of viscoelastic response of polymeric materials. Time-resolved pressure and pressure-rate measurements with PVDF piezoelectric polymer gauges are presented along with Manganin pressure and plate-dent test measurements of detonation pressure. Detonation pressures of 18GPa are indicated. Pressure measurements show initiation of reaction between 3 and 8 mm for an impact stress of 3.1 GPa. Plane wave loading wedge tests show run distances to detonation consistent with the pressure measurements, and with behavior like that of XTX8003 (80 % PETN/20 % Sylgard 182R).

  18. Imaging High Speed Particles in Explosive Driven Blast Waves

    NASA Astrophysics Data System (ADS)

    Jenkins, Charles; Horie, Yasuyuki

    2009-06-01

    Researchers Mr. Charles Jenkins and Dr. Yasuyuki Horie at the High Explosive Research & Development (HERD) facility at Eglin AFB with sponsorship from DTRA has successfully imaged high speed explosively driven metallic particles. The process uses an adapted, commercially available Particle Image Velocimetry (PIV) instrument. Regional and particle flow vectors are determined from particle displacement between two images taken in rapid succession. The instrument consists of a 120 mJ, pulsed Nd:YAG laser, camera system, synchronizer, and proprietary imaging software. The new PIV capability provides the ability for scientists and engineers to map explosively driven metallic particles in a blast wave. Characteristics of particle motion, interaction and dispersion can be determined by this method, providing measurements of key parameters such as particle size, shape, velocity, and concentration. This new capability to image and track small (from a few microns to as large as several hundred microns) high-speed particles without direct intervention by physical means, ensures that the particles are unchanged in their environment and provides greater measurement accuracy of particle dynamics in very short time scales. The capability can also be used to map large areas (square feet) or to zoom down at higher magnifications to study particle features such as particle agglomeration.

  19. Characterization Of High Explosives Detonations Via Laser-Induced Plasmas

    SciTech Connect

    Villa-Aleman, E.

    2015-10-08

    One objective of the Department of Energy’s National Security Administration is to develop technologies that can help the United States government to detect foreign nuclear weapons development activities. The realm of high explosive (HE) experiments is one of the key areas to assess the nuclear ambitions of a country. SRNL has participated in the collection of particulates from HE experiments and characterized the material with the purpose to correlate particulate matter with HE. Since these field campaigns are expensive, on-demand simulated laboratory-scale explosion experiments are needed to further our knowledge of the chemistry and particle formation in the process. Our goal is to develop an experimental test bed in the laboratory to test measurement concepts and correlate particle formation processes with the observables from the detonation fireball. The final objective is to use this knowledge to tailor our experimental setups in future field campaigns. The test bed uses pulsed laser-induced plasmas to simulate micro-explosions, with the intent to study the temporal behavior of the fireball observed in field tests. During FY15, a plan was prepared and executed which assembled two laser ablation systems, procured materials for study, and tested a Step-Scan Fourier Transform Infrared Spectrometer (SS-FTIR). Designs for a shadowgraph system for shock wave analysis, design for a micro-particulate collector from ablated pulse were accomplished. A novel spectroscopic system was conceived and a prototype system built for acquisition of spectral/temporal characterization of a high speed event such as from a high explosive detonation. Experiments and analyses will continue into FY16.

  20. Integrated Experiment and Modeling of Insensitive High Explosives

    NASA Astrophysics Data System (ADS)

    Stewart, D. Scott; Lambert, David E.; Yoo, Sunhee; Lieber, M.; Holman, Steven

    2009-06-01

    New design paradigms for insensitive high explosives are being sought for use in munitions applications that require enhanced, safety, reliability and performance. We describe recent work of our group that uses an integrated approach to develop predictive models, guided by experiments. Insensitive explosive can have relatively longer detonation reaction zones and slower reaction rates than their sensitive counterparts. We employ reactive flow models that are constrained by detonation shock dynamics to pose candidate predictive models. We discuss variation of the pressure dependent reaction rate exponent and reaction order, on the length of the supporting reaction zone, the detonation velocity curvature relation, computed critical energy required for initiation, the relation between the diameter effect curve and the corresponding normal detonation velocity curvature relation. We discuss representative characterization experiments carried out at Eglin, AFB and the constraints imposed on models by a standardized experimental characterization sequence.

  1. Integrated Experiment and Modeling of Insensitive High Explosives

    NASA Astrophysics Data System (ADS)

    Stewart, D. Scott; Lambert, David E.; Yoo, Sunhee; Lieber, Mark; Holman, Steven

    2009-12-01

    New design paradigms for insensitive high explosives are being sought for use in munitions applications that require enhanced safety, reliability and performance. We describe recent work of our group that uses an integrated approach to develop predictive models, guided by experiments. Insensitive explosive can have relatively longer detonation reaction zones and slower reaction rates than their sensitive counterparts. We employ reactive flow models that are constrained by detonation shock dynamics (DSD) to pose candidate predictive models. We discuss the variation of the pressure dependent reaction rate exponent and reaction order on the length of the supporting reaction zone, the detonation velocity curvature relation, the computed critical energy required for initiation, the relation between the diameter effect curve and the corresponding normal detonation velocity curvature relation.

  2. High explosive violent reaction (HEVR) from slow heating conditions

    SciTech Connect

    Vigil, A.S.

    1999-03-01

    The high explosives (HEs) developed and used at the Los Alamos National Laboratory are designed to be insensitive to impact and thermal insults under all but the most extreme conditions. Nevertheless, violent reactions do occasionally occur when HE is involved in an accident. The HE response is closely dependent on the type of external stimulus that initiates the reaction. For example, fast heating of conventional HE will probably result in fairly benign burning, while long-term, slow heating of conventional HE is more likely to produce an HEVR that will do much more damage to the immediate surroundings. An HEVR (High Explosive Violent Reaction) can be defined as the rapid release of energy from an explosive that ranges from slightly faster than a deflagration (very rapid burning) to a reaction that approaches a detonation. A number of thermal analyses have been done to determine slow heat/cook-off conditions that produce HE self-heating that can build up to a catastrophic runaway reaction. The author specifies the conditions that control reaction violence, describes experiments that produced an HEVR, describes analyses done to determine a heating rate threshold for HEVR, and lists possible HEVR situations.

  3. High-speed imaging of explosive eruptions: applications and perspectives

    NASA Astrophysics Data System (ADS)

    Taddeucci, Jacopo; Scarlato, Piergiorgio; Gaudin, Damien; Capponi, Antonio; Alatorre-Ibarguengoitia, Miguel-Angel; Moroni, Monica

    2013-04-01

    Explosive eruptions, being by definition highly dynamic over short time scales, necessarily call for observational systems capable of relatively high sampling rates. "Traditional" tools, like as seismic and acoustic networks, have recently been joined by Doppler radar and electric sensors. Recent developments in high-speed camera systems now allow direct visual information of eruptions to be obtained with a spatial and temporal resolution suitable for the analysis of several key eruption processes. Here we summarize the methods employed to gather and process high-speed videos of explosive eruptions, and provide an overview of the several applications of these new type of data in understanding different aspects of explosive volcanism. Our most recent set up for high-speed imaging of explosive eruptions (FAMoUS - FAst, MUltiparametric Set-up,) includes: 1) a monochrome high speed camera, capable of 500 frames per second (fps) at high-definition (1280x1024 pixel) resolution and up to 200000 fps at reduced resolution; 2) a thermal camera capable of 50-200 fps at 480-120x640 pixel resolution; and 3) two acoustic to infrasonic sensors. All instruments are time-synchronized via a data logging system, a hand- or software-operated trigger, and via GPS, allowing signals from other instruments or networks to be directly recorded by the same logging unit or to be readily synchronized for comparison. FAMoUS weights less than 20 kg, easily fits into four, hand-luggage-sized backpacks, and can be deployed in less than 20' (and removed in less than 2', if needed). So far, explosive eruptions have been recorded in high-speed at several active volcanoes, including Fuego and Santiaguito (Guatemala), Stromboli (Italy), Yasur (Vanuatu), and Eyjafiallajokull (Iceland). Image processing and analysis from these eruptions helped illuminate several eruptive processes, including: 1) Pyroclasts ejection. High-speed videos reveal multiple, discrete ejection pulses within a single Strombolian

  4. Research and Development of High-performance Explosives

    PubMed Central

    Cornell, Rodger; Wrobel, Erik; Anderson, Paul E.

    2016-01-01

    Developmental testing of high explosives for military applications involves small-scale formulation, safety testing, and finally detonation performance tests to verify theoretical calculations. small-scale For newly developed formulations, the process begins with small-scale mixes, thermal testing, and impact and friction sensitivity. Only then do subsequent larger scale formulations proceed to detonation testing, which will be covered in this paper. Recent advances in characterization techniques have led to unparalleled precision in the characterization of early-time evolution of detonations. The new technique of photo-Doppler velocimetry (PDV) for the measurement of detonation pressure and velocity will be shared and compared with traditional fiber-optic detonation velocity and plate-dent calculation of detonation pressure. In particular, the role of aluminum in explosive formulations will be discussed. Recent developments led to the development of explosive formulations that result in reaction of aluminum very early in the detonation product expansion. This enhanced reaction leads to changes in the detonation velocity and pressure due to reaction of the aluminum with oxygen in the expanding gas products. PMID:26966969

  5. Research and Development of High-performance Explosives.

    PubMed

    Cornell, Rodger; Wrobel, Erik; Anderson, Paul E

    2016-01-01

    Developmental testing of high explosives for military applications involves small-scale formulation, safety testing, and finally detonation performance tests to verify theoretical calculations. small-scale For newly developed formulations, the process begins with small-scale mixes, thermal testing, and impact and friction sensitivity. Only then do subsequent larger scale formulations proceed to detonation testing, which will be covered in this paper. Recent advances in characterization techniques have led to unparalleled precision in the characterization of early-time evolution of detonations. The new technique of photo-Doppler velocimetry (PDV) for the measurement of detonation pressure and velocity will be shared and compared with traditional fiber-optic detonation velocity and plate-dent calculation of detonation pressure. In particular, the role of aluminum in explosive formulations will be discussed. Recent developments led to the development of explosive formulations that result in reaction of aluminum very early in the detonation product expansion. This enhanced reaction leads to changes in the detonation velocity and pressure due to reaction of the aluminum with oxygen in the expanding gas products. PMID:26966969

  6. PINS Measurements and Simulations for Stand-Off Detection of High Explosives

    SciTech Connect

    E.H. Seabury

    2011-07-01

    There has been some interest in the ability of Idaho National Laboratory's (INL) Portable Isotopic Neutron Spectroscopy System's (PINS) ability to detect high explosives at a distance. In order to assess the system's ability to perform this task, laboratory experiments on simulated or mock explosives and Monte Carlo simulations using MCNP on both mock and real explosives have been performed. The simulations and experiments on mock explosives have essentially identical configurations, allowing the models to be confirmed with experiment. This provides greater confidence in the simulations on real explosives without the need for experiment on live explosives.

  7. A case of death from the explosion of a 66mm M72 High Explosive Anti-Tank rocket.

    PubMed

    Ihama, Yoko; Miyazaki, Tetsuji; Fuke, Chiaki; Taira, Zenshin

    2008-07-01

    A 53-year-old male died from an explosion of a 66 mm M72 High Explosive Anti-Tank (HEAT) rocket. He had collected various cast-off military weapons and was selling them. There were numerous explosive injuries on the anterior side of the body, thus especially bilateral hands, left toe and right knee were severely crushed and fractured. The location and severity of the injuries suggest that he was down on his left knee and was manipulating the weapon with both hands at the moment of detonation. We consider that 66 mm M72 HEAT rocket accidentally detonated during his handling. Very rarely are civilians killed by a military weapon, except during wartime. Appropriate investigation of various explosive injuries provide not only evidence of the cause of death, but also the position and posture of the body. PMID:18346924

  8. Conversion of high explosive chemical energy into energy of powerful nanosecond high-current pulses

    NASA Astrophysics Data System (ADS)

    Gorbachev, K. V.; Mikhaylov, V. M.; Nesterov, E. V.; Stroganov, V. A.; Chernykh, E. V.

    2015-01-01

    This study is a contribution into the development of physicotechnical foundations for generation of powerful nanosecond high-current pulses on the basis of explosively driven magnetic flux compression generators. This problem is solved by using inductive storage of energy for matching comparatively low-voltage explosively driven magnetic flux compression generators and high-impedance loads; short forming lines and vacuum diodes. Experimental data of charging of forming lines are given.

  9. A second survey of high explosives traces in public places.

    PubMed

    Cullum, Hazel E; McGavigan, Claire; Uttley, Claire Z; Stroud, Mark A M; Warren, Derek C

    2004-07-01

    This survey was carried out as a follow-up to a 1994 survey carried out by this laboratory (1) in order to determine the background levels of explosives traces in public places. The first survey concentrated on transport areas and police stations in and around London. This second study examines levels in four of the United Kingdom's major cities: Birmingham, Cardiff, Glasgow, and Manchester. Samples were taken at various transport sites and from hotels, private houses, private vehicles, and clothing. The survey showed that traces of the high explosives nitroglycerine (NG), trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), and cyclotrimethylene trinitramine (RDX) are rare within the general public environment. Only one low-level trace of RDX was detected. NG, possibly associated with the use of firearms, was detected at low levels in two samples and 2,4-DNT was detected in a separate sample. No PETN was detected in any of the samples. The results of the survey indicate that it is unlikely that persons visiting public areas could become significantly contaminated with explosives. The analytical procedures employed would also have detected ethylene glycol dinitrate (EGDN) if present at levels greater than 2 ng, nitrobenzene (NB) if present at levels greater than 50 ng, mononitrotoluenes if present at levels greater than 50 ng, and the other common isomers of dinitrotoluene if these had been present at levels in excess of 10 ng. None of these were detected. The relatively high volatility of EGDN, NB, and the mononitrotoluenes would, however, cause traces of these compounds to disperse rapidly. A proportion of the samples (approximately 7%) were analyzed for the presence of HMX. No HMX was detected. PMID:15317181

  10. Study of high explosives in soil for holding determination

    SciTech Connect

    Tappan, B.C.; Campbell, M.S.

    1997-12-31

    A holding time is a regulated amount of time that a sample can be stored before analysis. The holding times that are now used for high explosives (HE) in soil and extracts are the EPA holding times set for semi-volatile organics. These holding times are 14 days at 4 C before sample extraction and 40 days before extract analysis. A previous study on Eastern U.S. soils found that actual decomposition in storage varies for different compounds and different soils, however, no studies prior to this have been performed on Los Alamos soils. The soil samples were spiked with an HE solution of HMX, RDX, TNT, TNB, 2,4-DNT, 2,6-DNT, 4-Am-2,6-DNT, 2-Am-4,6-DNT, Tetryl, NB, 1,3-DNB, 2-NT, 3-NT, and 4-NT, plus two surrogates 3,4-DNT and MNA. A total of five soil types were studied, four uncontaminated and one field contaminated. From the results of the study, it is clear that the EPA holding time now assigned to soils containing high explosives is much too long when analyzing for nitroaromatics, but sufficient when analyzing for HMX and RDX.

  11. High Explosive Verification and Validation: Systematic and Methodical Approach

    NASA Astrophysics Data System (ADS)

    Scovel, Christina; Menikoff, Ralph

    2011-06-01

    Verification and validation of high explosive (HE) models does not fit the standard mold for several reasons. First, there are no non-trivial test problems with analytic solutions. Second, an HE model depends on a burn rate and the equation of states (EOS) of both the reactants and products. Third, there is a wide range of detonation phenomena from initiation under various stimuli to propagation of curved detonation fronts with non-rigid confining materials. Fourth, in contrast to a shock wave in a non-reactive material, the reaction-zone width is physically significant and affects the behavior of a detonation wave. Because of theses issues, a systematic and methodical approach to HE V & V is needed. Our plan is to build a test suite from the ground up. We have started with the cylinder test and have run simulations with several EOS models and burn models. We have compared with data and cross-compared the different runs to check on the sensitivity to model parameters. A related issue for V & V is what experimental data are available for calibrating and testing models. For this purpose we have started a WEB based high explosive database (HED). The current status of HED will be discussed.

  12. Photoactive High Explosives: Substituents Effects on Tetrazine Photochemistry and Photophysics.

    PubMed

    McGrane, S D; Bolme, C A; Greenfield, M T; Chavez, D E; Hanson, S K; Scharff, R J

    2016-02-18

    High explosives that are photoactive, i.e., can be initiated with light, offer significant advantages in reduced potential for accidental electrical initiation. We examined a series of structurally related tetrazine based photoactive high explosive materials to detail their photochemical and photophysical properties. Using photobleaching infrared absorption, we determined quantum yields of photochemistry for nanosecond pulsed excitation at 355 and 532 nm. Changes in mass spectrometry during laser irradiation in vacuum measured the evolution of gaseous products. Fluorescence spectra, quantum yields, and lifetimes were measured to observe radiative channels of energy decay that compete with photochemistry. For the 6 materials studied, quantum yields of photochemistry ranged from <10(-5) to 0.03 and quantum yield of fluorescence ranged from <10(-3) to 0.33. In all cases, the photoexcitation nonradiatively relaxed primarily to heat, appropriate for supporting photothermal initiation processes. The photochemistry observed was dominated by ring scission of the tetrazine, but there was evidence of more extensive multistep reactions as well. PMID:26797486

  13. An explosively driven high-power microwave pulsed power system

    NASA Astrophysics Data System (ADS)

    Elsayed, M. A.; Neuber, A. A.; Dickens, J. C.; Walter, J. W.; Kristiansen, M.; Altgilbers, L. L.

    2012-02-01

    The increased popularity of high power microwave systems and the various sources to drive them is the motivation behind the work to be presented. A stand-alone, self-contained explosively driven high power microwave pulsed power system has been designed, built, and tested at Texas Tech University's Center for Pulsed Power and Power Electronics. The system integrates four different sub-units that are composed of a battery driven prime power source utilizing capacitive energy storage, a dual stage helical flux compression generator as the main energy amplification device, an integrated power conditioning system with inductive energy storage including a fast opening electro-explosive switch, and a triode reflex geometry virtual cathode oscillator as the microwave radiating source. This system has displayed a measured electrical source power level of over 5 GW and peak radiated microwaves of about 200 MW. It is contained within a 15 cm diameter housing and measures 2 m in length, giving a housing volume of slightly less than 39 l. The system and its sub-components have been extensively studied, both as integrated and individual units, to further expand on components behavior and operation physics. This report will serve as a detailed design overview of each of the four subcomponents and provide detailed analysis of the overall system performance and benchmarks.

  14. Field-based high-speed imaging of explosive eruptions

    NASA Astrophysics Data System (ADS)

    Taddeucci, J.; Scarlato, P.; Freda, C.; Moroni, M.

    2012-12-01

    Explosive eruptions involve, by definition, physical processes that are highly dynamic over short time scales. Capturing and parameterizing such processes is a major task in eruption understanding and forecasting, and a task that necessarily requires observational systems capable of high sampling rates. Seismic and acoustic networks are a prime tool for high-frequency observation of eruption, recently joined by Doppler radar and electric sensors. In comparison with the above monitoring systems, imaging techniques provide more complete and direct information of surface processes, but usually at a lower sampling rate. However, recent developments in high-speed imaging systems now allow such information to be obtained with a spatial and temporal resolution suitable for the analysis of several key eruption processes. Our most recent set up for high-speed imaging of explosive eruptions (FAMoUS - FAst, MUltiparametric Set-up,) includes: 1) a monochrome high speed camera, capable of 500 frames per second (fps) at high-definition (1280x1024 pixel) resolution and up to 200000 fps at reduced resolution; 2) a thermal camera capable of 50-200 fps at 480-120x640 pixel resolution; and 3) two acoustic to infrasonic sensors. All instruments are time-synchronized via a data logging system, a hand- or software-operated trigger, and via GPS, allowing signals from other instruments or networks to be directly recorded by the same logging unit or to be readily synchronized for comparison. FAMoUS weights less than 20 kg, easily fits into four, hand-luggage-sized backpacks, and can be deployed in less than 20' (and removed in less than 2', if needed). So far, explosive eruptions have been recorded in high-speed at several active volcanoes, including Fuego and Santiaguito (Guatemala), Stromboli (Italy), Yasur (Vanuatu), and Eyjafiallajokull (Iceland). Image processing and analysis from these eruptions helped illuminate several eruptive processes, including: 1) Pyroclasts ejection. High

  15. Laser methods for detecting explosive residues on surfaces of distant objects

    SciTech Connect

    Skvortsov, L A

    2012-01-31

    The basic methods of laser spectroscopy that are used for standoff detection and identification of explosive traces in the form of particles on the surfaces of objects tested under real or close-toreal conditions are briefly considered. The advantages and drawbacks of all methods are discussed and their characteristics are compared. Particular attention has been given to the prospects of development and practical implementation of the technologies discussed and justification of their most preferred applications. (review)

  16. Laser impingement on bare and encased high explosives: safety limits

    SciTech Connect

    Roeske, F

    1999-03-15

    During the course of experiments involving high explosives, (HE), alignment lasers are often employed where the laser beam impinges upon a metal encased HE sample or on the bare HE itself during manned operations. While most alignment lasers are of low enough power so as not to be of concern, safety questions arise when considering the maximum credible power output of the laser in a failure mode, or when multiple laser spots are focused onto the experiment simultaneously. Safety questions also arise when the focused laser spot size becomes very small, on the order of 100 {micro}m or less. This paper addresses these concerns by describing a methodology for determining safety margins for laser impingement on metal encased HE as well as one for bare HE. A variety of explosives encased in Al, Cu, Ta and stainless steel were tested using the first of these techniques. Additional experiments were performed using the second method where the laser beam was focused directly on eight different samples of pressed-powder HE.

  17. High Resolution Digital Elevation Models of Pristine Explosion Craters

    NASA Technical Reports Server (NTRS)

    Farr, T. G.; Krabill, W.; Garvin, J. B.

    2004-01-01

    In order to effectively capture a realistic terrain applicable to studies of cratering processes and landing hazards on Mars, we have obtained high resolution digital elevation models of several pristine explosion craters at the Nevada Test Site. We used the Airborne Terrain Mapper (ATM), operated by NASA's Wallops Flight Facility to obtain DEMs with 1 m spacing and 10 cm vertical errors of 4 main craters and many other craters and collapse pits. The main craters that were mapped are Sedan, Scooter, Schooner, and Danny Boy. The 370 m diameter Sedan crater, located on Yucca Flat, is the largest and freshest explosion crater on Earth that was formed under conditions similar to hypervelocity impact cratering. As such, it is effectively pristine, having been formed in 1962 as a result of a controlled detonation of a 100 kiloton thermonuclear device, buried at the appropriate equivalent depth of burst required to make a simple crater. Sedan was formed in alluvium of mixed lithology and subsequently studied using a variety of field-based methods. Nearby secondary craters were also formed at the time and were also mapped by ATM. Adjacent to Sedan and also in alluvium is Scooter, about 90 m in diameter and formed by a high-explosive event. Schooner (240 m) and Danny Boy (80 m) craters were also important targets for ATM as they were excavated in hard basalt and therefore have much rougher ejecta. This will allow study of ejecta patterns in hard rock as well as engineering tests of crater and rock avoidance and rover trafficability. In addition to the high resolution DEMs, crater geometric characteristics, RMS roughness maps, and other higher-order derived data products will be generated using these data. These will provide constraints for models of landing hazards on Mars and for rover trafficability. Other planned studies will include ejecta size-frequency distribution at the resolution of the DEM and at finer resolution through air photography and field measurements

  18. Continued development of a portable widefield hyperspectral imaging (HSI) sensor for standoff detection of explosive, chemical, and narcotic residues

    NASA Astrophysics Data System (ADS)

    Nelson, Matthew P.; Gardner, Charles W.; Klueva, Oksana; Tomas, David

    2014-05-01

    Passive, standoff detection of chemical, explosive and narcotic threats employing widefield, shortwave infrared (SWIR) hyperspectral imaging (HSI) continues to gain acceptance in defense and security fields. A robust and user-friendly portable platform with such capabilities increases the effectiveness of locating and identifying threats while reducing risks to personnel. In 2013 ChemImage Sensor Systems (CISS) introduced Aperio, a handheld sensor, using real-time SWIR HSI for wide area surveillance and standoff detection of explosives, chemical threats, and narcotics. That SWIR HSI system employed a liquid-crystal tunable filter for real-time automated detection and display of threats. In these proceedings, we report on a next generation device called VeroVision™, which incorporates an improved optical design that enhances detection performance at greater standoff distances with increased sensitivity and detection speed. A tripod mounted sensor head unit (SHU) with an optional motorized pan-tilt unit (PTU) is available for precision pointing and sensor stabilization. This option supports longer standoff range applications which are often seen at checkpoint vehicle inspection where speed and precision is necessary. Basic software has been extended to include advanced algorithms providing multi-target display functionality, automatic threshold determination, and an automated detection recipe capability for expanding the library as new threats emerge. In these proceedings, we report on the improvements associated with the next generation portable widefield SWIR HSI sensor, VeroVision™. Test data collected during development are presented in this report which supports the targeted applications for use of VeroVision™ for screening residue and bulk levels of explosive and drugs on vehicles and personnel at checkpoints as well as various applications for other secure areas. Additionally, we highlight a forensic application of the technology for assisting forensic

  19. Evaluation of soluble fraction and enzymatic residual fraction of dilute dry acid, ethylenediamine, and steam explosion pretreated corn stover on the enzymatic hydrolysis of cellulose.

    PubMed

    Qin, Lei; Liu, Li; Li, Wen-Chao; Zhu, Jia-Qing; Li, Bing-Zhi; Yuan, Ying-Jin

    2016-06-01

    This study is aimed to examine the inhibition of soluble fraction (SF) and enzymatic residual fraction (ERF) in dry dilute acid (DDA), ethylenediamine (EDA) and steam explosion (SE) pretreated corn stover (CS) on the enzymatic digestibility of cellulose. SF of DDA, EDA and SE pretreated CS has high xylose, soluble lignin and xylo-oligomer content, respectively. SF of EDA pretreated CS leads to the highest inhibition, followed by SE and DDA pretreated CS. Inhibition of ERF of DDA and SE pretreated CS is higher than that of EDA pretreated CS. The inhibition degree (A0/A) of SF is 1.76 and 1.21 times to that of ERF for EDA and SE pretreated CS, respectively. The inhibition degree of ERF is 1.05 times to that of SF in DDA pretreated CS. The quantitative analysis shows that SF of EDA pretreated CS, SF and ERF of SE pretreated CS cause significant inhibition during enzymatic hydrolysis. PMID:26970919

  20. High level triggers for explosive mafic volcanism: Albano Maar, Italy

    NASA Astrophysics Data System (ADS)

    Cross, J. K.; Tomlinson, E. L.; Giordano, G.; Smith, V. C.; De Benedetti, A. A.; Roberge, J.; Manning, C. J.; Wulf, S.; Menzies, M. A.

    2014-03-01

    Colli Albani is a quiescent caldera complex located within the Roman Magmatic Province (RMP), Italy. The recent Via dei Laghi phreatomagmatic eruptions led to the formation of nested maars. Albano Maar is the largest and has erupted seven times between ca 69-33 ka. The highly explosive nature of the Albano Maar eruptions is at odds with the predominant relatively mafic (SiO2 = 48-52 wt.%) foiditic (K2O = 9 wt.%) composition of the magma. The deposits have been previously interpreted as phreatomagmatic, however they contain large amounts (up to 30%vol) of deep seated xenoliths, skarns and all pre-volcanic subsurface units. All of the xenoliths have been excavated from depths of up to 6 km, rather than being limited to the depth at which magma and water interaction is likely to have occurred, suggesting an alternative trigger for eruption. High precision geochemical glass and mineral data of fresh juvenile (magmatic) clasts from the small volume explosive deposits indicate that the magmas have evolved along one of two evolutionary paths towards foidite or phonolite. The foiditic melts record ca. 50% mixing between the most primitive magma and Ca-rich melt, late stage prior to eruption. A major result of our study is finding that the generation of Ca-rich melts via assimilation of limestone, may provide storage for significant amounts of CO2 that can be released during a mixing event with silicate magma. Differences in melt evolution are inferred as having been controlled by variations in storage conditions: residence time and magma volume.

  1. PVDF shock sensors: applications to polar materials and high explosives.

    PubMed

    Bauer, F

    2000-01-01

    Ferroelectric polymers (PVDF) with well-defined and precisely known electrical properties are now routinely available from commercial sources. Electrical processing with the Bauer cyclic poling method can produce individual films with well-defined remanent polarization up to 9 /spl mu/C/cm/sup 2/. These polymers provide an unusual opportunity to study the structure and physical properties of materials subjected to shock loading. The behavior of PVDF has been studied over a wide range of pressures using high-pressure shock loading and has yielded well-behaved, reproducible data up to 25 GPa in inert materials. The application of PVDF gauges for recording shock waves induced in polar materials such as Kel-F, PMMA, or in reactive materials is hampered by observations of anomalous responses due to shock-induced polarization or an electrical charge released inside a shock-compressed explosive. A solution using an appropriate electrical shielding has been identified and applied to PVDF for shock measurement studies of Kel-F, and for Hugoniot measurements of high explosives (PH). Furthermore, shock pressure profiles obtained with in situ PVDF gauges in porous HE (Formex) in a detonation regime have been achieved. Typical results of shock pressure profile versus time show a fast superpressure of a few nanoseconds followed by a pressure release down to a plateau level and then by a pressure decay. More accurate measurements are reported with electrically improved PVDF gauges as well as with 0.25 mm/sup 2/ active area PVDF gauges. PMID:18238691

  2. Moderate Velocity Ball Impact of a Mock High-Explosive

    SciTech Connect

    Furmanski, Jevan; Rae, Philip; Clements, Bradford E.

    2012-06-05

    Modeling of thermal and mechanical events in high-explosive materials is complicated by the composite nature of the material, which experiences viscoelastic and plastic deformations and sustains damage in the form of microcracks that can dominate its overall behavior. A mechanical event of interest is projectile interaction with the material, which leads to extreme local deformation and adiabatic heating, which can potentially lead to adverse outcomes in an energetic material. Simulations of such an event predicted large local temperature rises near the path of a spherical projectile, but these were experimentally unconfirmed and hence potentially non-physical. This work concerns the experimental verification of local temperatures both at the surface and in the wake of a spherical projectile penetrating a mock (unreactive) high-explosive at {approx}700 m/s. Fast response thermocouples were embedded radially in a mid-plane of a cylindrical target, which was bonded around the thermocouples with epoxy and recorded by an oscilloscope through a low-pass filter with a bandwidth of 500 Hz. A peak temperature rise of 70 K was measured both at the equator of the projectile and in its wake, in good agreement with the temperature predicted in the minimally distorted elements at those locations by a finite element model in ABAQUS employing the ViscoSCRAM constitutive model. Further work is needed to elucidate the extreme temperature rises in material undergoing crushing or fragmentation, which is difficult to predict with meshed finite element methods due to element distortion, and also challenging to quantify experimentally.

  3. Identification of inorganic improvised explosive devices by analysis of postblast residues using portable capillary electrophoresis instrumentation and indirect photometric detection with a light-emitting diode.

    PubMed

    Hutchinson, Joseph P; Evenhuis, Christopher J; Johns, Cameron; Kazarian, Artaches A; Breadmore, Michael C; Macka, Miroslav; Hilder, Emily F; Guijt, Rosanne M; Dicinoski, Greg W; Haddad, Paul R

    2007-09-15

    A commercial portable capillary electrophoresis (CE) instrument has been used to separate inorganic anions and cations found in postblast residues from improvised explosive devices (IEDs) of the type used frequently in terrorism attacks. The purpose of this analysis was to identify the type of explosive used. The CE instrument was modified for use with an in-house miniaturized light-emitting diode (LED) detector to enable sensitive indirect photometric detection to be employed for the detection of 15 anions (acetate, benzoate, carbonate, chlorate, chloride, chlorite, cyanate, fluoride, nitrate, nitrite, perchlorate, phosphate, sulfate, thiocyanate, thiosulfate) and 12 cations (ammonium, monomethylammonium, ethylammonium, potassium, sodium, barium, strontium, magnesium, manganese, calcium, zinc, lead) as the target analytes. These ions are known to be present in postblast residues from inorganic IEDs constructed from ammonium nitrate/fuel oil mixtures, black powder, and chlorate/perchlorate/sugar mixtures. For the analysis of cations, a blue LED (470 nm) was used in conjunction with the highly absorbing cationic dye, chrysoidine (absorption maximum at 453 nm). A nonaqueous background electrolyte comprising 10 mM chrysoidine in methanol was found to give greatly improved baseline stability in comparison to aqueous electrolytes due to the increased solubility of chrysoidine and its decreased adsorption onto the capillary wall. Glacial acetic acid (0.7% v/v) was added to ensure chrysoidine was protonated and to enhance separation selectivity by means of complexation with transition metal ions. The 12 target cations were separated in less than 9.5 min with detection limits of 0.11-2.30 mg/L (calculated at a signal-to-noise ratio of 3). The anions separation system utilized a UV LED (370 nm) in conjunction with an aqueous chromate electrolyte (absorption maximum at 371 nm) consisting of 10 mM chromium(VI) oxide and 10 mM sodium chromate, buffered with 40 mM tris

  4. The High Resolution Tropospheric Ozone Residual

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.

    2006-01-01

    The co-flight of the MLS stratospheric limb sounder and the Ozone Monitoring Instrument (OMI) provides the capability of computing the Tropospheric Ozone Residual (TOR) in much greater detail [Ziemke et al., 2006]. Using forward trajectory calculations of MLS ozone measurements combined with OMI column ozone we have developed a high horizontal resolution tropospheric ozone residual (HTOR) which can provide even more detail than the standard TOR product. HTOR is especially useful for extra-tropical studies of tropospheric ozone transport. We find that both the Pacific pollution corridor (East Asia to Alaska) and the Atlantic pollution corridor (North America east coast to Europe) are also preferred locations for strat-trop folds leading to systematic overestimates of pollution amounts. In fact, fold events appear to dominate extra-tropical Northern Hemisphere day-to-day maps of HTOR. Model estimates of the tropospheric column are in reasonable agreement with the HTOR amounts when offsets due to different tropopause height calculations are taken into consideration.

  5. A cone on Mercury: Analysis of a residual central peak encircled by an explosive volcanic vent

    NASA Astrophysics Data System (ADS)

    Thomas, Rebecca J.; Lucchetti, Alice; Cremonese, Gabriele; Rothery, David A.; Massironi, Matteo; Re, Cristina; Conway, Susan J.; Anand, Mahesh

    2015-04-01

    We analyse a seemingly-unique landform on Mercury: a conical structure, encircled by a trough, and surrounded by a 23,000 km2 relatively bright and red anomaly of a type interpreted elsewhere on the planet as a pyroclastic deposit. At first glance, this could be interpreted as a volcanically-constructed cone, but if so, it would be the only example of such a landform on Mercury. We make and test the alternative hypothesis that the cone is the intrinsic central peak of an impact crater, the rim crest of which is visible beyond the cone-encircling trough, and that the trough is a vent formed through explosive volcanism that also produced the surrounding bright, red spectral anomaly. We test this hypothesis by comparing the morphology of the cone and the associated landform assemblage with morphologically-fresh impact craters of the same diameter as the putative host crater, and additionally, by modelling the original morphology of such a crater using a hydrocode model. We show that the present topography can be explained by formation of a vent completely encircling the crater's central peak and also make the observation that explosive volcanic vents frequently occur circumferential to the central peaks of impact craters on Mercury. This indicates that, although this cone initially appears unique, it is in fact an unusually well-developed example of a common process by which impact-related faults localize magma ascent near the centre of impact craters on Mercury, and represents an extreme end-member of the resulting landforms.

  6. DMSO/base hydrolysis method for the disposal of high explosives and related energetic materials

    DOEpatents

    Desmare, Gabriel W.; Cates, Dillard M.

    2002-05-14

    High explosives and related energetic materials are treated via a DMSO/base hydrolysis method which renders them non-explosive and/or non-energetic. For example, high explosives such as 1,3,5,7-tetraaza-1,3,5,7-tetranitrocyclooctane (HMX), 1,3,5-triaza-1,3,5-trinitrocyclohexane (RDX), 2,4,6-trinitrotoluene (TNT), or mixtures thereof, may be dissolved in a polar, aprotic solvent and subsequently hydrolyzed by adding the explosive-containing solution to concentrated aqueous base. Major hydrolysis products typically include nitrite, formate, and nitrous oxide.

  7. Model testing of a 1-kg high-explosive-cell maze

    SciTech Connect

    Bacigalupi, C.M.; Burton, W.A.

    1981-04-01

    The basement of the proposed High Explosives Applications Facility (Building 353) at the Lawrence Livermore National Laboratory includes several explosive test cells for the assembly and/or storage of up to 10 kg of high explosive (HE). This document reports 1/8-scale and 1/4-scale model tests conducted to confirm maze design criteria, to determine the cell explosive weight limit based on an allowable 10 psi reflected shock pressure at the hallway-maze doorway, and to specify permissible areas for handling HE within the cell. The integrity of cube-root scaling of the explosive charges detonated in the 1/8-scale model was verified by explosive testing in a comparable 1/4-scale model. Reflected shock pressures in the hallway adjacent to the maze and the effect of HE charge orientation were investigated and are also reported.

  8. Study of Spatially Resolved Temperature Diagnostics for High Explosives

    SciTech Connect

    Lee, H

    2000-04-05

    The next generation of 2-D and 3-D weapon-simulation codes will require marked advances in the spatial and temporal resolution of the various diagnostics to verify the complex physics predicted from these calculations. This is particularly true for the complicated physics of high-explosive (HE) detonation and burn, of which a detailed understanding is crucial to nuclear weapons performance and integrity. The processes involved in the detonation of HEs occur very rapidly and lead to extremely high pressures (several GPa) and temperatures (several thousand Kelvin). A key diagnostic that has so far eluded experimentalists is a temperature diagnostic for burning HE. Temperature is a basic thermodynamic property that enables a fundamental understanding of important HE physics such as the chemical processes involved in the shock-to-detonation transition, and to assess the thermal part of the equation-of-state of the detonation products. Accurate, spatially localized temperature measurements with high temporal resolution are thus crucial, but are unfortunately lacking. Our work address this important problem.

  9. High-Yield Magnetized Liner Fusion Explosions and Blast Mitigation

    NASA Astrophysics Data System (ADS)

    Slutz, Stephen; Vesey, Roger; Cuneo, Michael

    2011-10-01

    Cylindrical liner implosions with preheated and magnetized deuterium-tritium (DT) are predicted to reach fusion conditions on present pulsed power machines [S.A. Slutz et al Phys. Plasmas 17, 056303 (2010)]. We present simulations indicating that high yields (1-10 GJ) and gains (100-1000) may be possible at currents of about 60-70 MA if a cryogenic layer of solid DT is provided on the inside surface of the metal liner. A hot spot is formed from the central preheated magnetized low-density gas and a burn wave propagates radially into the surrounding cold dense fuel. These yields and gains are more than adequate for inertial fusion energy. However, the pulsed-power driver must be protected from the blast of these high-yield explosions. Numerical simulations are presented which show that the blast can be deflected and the fusion neutrons absorbed by a blanket that partially surrounds the liner. Thus a modest length transmission line can be used to deliver power to the liner. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  10. Systematic approach to verification and validation: High explosive burn models

    SciTech Connect

    Menikoff, Ralph; Scovel, Christina A.

    2012-04-16

    Most material models used in numerical simulations are based on heuristics and empirically calibrated to experimental data. For a specific model, key questions are determining its domain of applicability and assessing its relative merits compared to other models. Answering these questions should be a part of model verification and validation (V and V). Here, we focus on V and V of high explosive models. Typically, model developers implemented their model in their own hydro code and use different sets of experiments to calibrate model parameters. Rarely can one find in the literature simulation results for different models of the same experiment. Consequently, it is difficult to assess objectively the relative merits of different models. This situation results in part from the fact that experimental data is scattered through the literature (articles in journals and conference proceedings) and that the printed literature does not allow the reader to obtain data from a figure in electronic form needed to make detailed comparisons among experiments and simulations. In addition, it is very time consuming to set up and run simulations to compare different models over sufficiently many experiments to cover the range of phenomena of interest. The first difficulty could be overcome if the research community were to support an online web based database. The second difficulty can be greatly reduced by automating procedures to set up and run simulations of similar types of experiments. Moreover, automated testing would be greatly facilitated if the data files obtained from a database were in a standard format that contained key experimental parameters as meta-data in a header to the data file. To illustrate our approach to V and V, we have developed a high explosive database (HED) at LANL. It now contains a large number of shock initiation experiments. Utilizing the header information in a data file from HED, we have written scripts to generate an input file for a hydro code

  11. Biodegradation of the High Explosive Hexanitrohexaazaiso-wurtzitane (CL-20)

    PubMed Central

    Karakaya, Pelin; Christodoulatos, Christos; Koutsospyros, Agamemnon; Balas, Wendy; Nicolich, Steve; Sidhoum, Mohammed

    2009-01-01

    The aerobic biodegradability of the high explosive CL-20 by activated sludge and the white rot fungus Phanerochaete chrysosporium has been investigated. Although activated sludge is not effective in degrading CL-20 directly, it can mineralize the alkaline hydrolysis products. Phanerochaete chrysosporium degrades CL-20 in the presence of supplementary carbon and nitrogen sources. Biodegradation studies were conducted using various nutrient media under diverse conditions. Variables included the CL-20 concentration; levels of carbon (as glycerol) and ammonium sulfate and yeast extract as sources of nitrogen. Cultures that received CL-20 at the time of inoculation transformed CL-20 completely under all nutrient conditions studied. When CL-20 was added to pre-grown cultures, degradation was limited. The extent of mineralization was monitored by the 14CO2 time evolution; up to 51% mineralization was achieved when the fungus was incubated with [14C]-CL-20. The kinetics of CL-20 biodegradation by Phanerochaete chrysosporium follows the logistic kinetic growth model. PMID:19440524

  12. Tilt Correction of High Explosive Test Data with Examples

    NASA Astrophysics Data System (ADS)

    Hill, Larry; Francois, Elizabeth; Morris, John

    2013-06-01

    Many high-explosive experiments view a nominally-axially-symmetric detonation wave breaking through a charge surface. Emerging waves virtually always exhibit a degree of tilt, which one generally wants to excise from the data whilst quantifying its direction and magnitude. In some cases, such as front-curvature rate sticks and Onionskin (OS)-type tests, the diagnostic is a single-slit streak camera (1D correction). In other cases, such as a Plane-Wave Lens characterization test or a Furball test, multiple slits or fibers provide sparse data over a surface (2D correction). We demonstrate both 1D and 2D corrections, the latter of which is the more challenging. In 2D, we represent the breakout time as the sum of a symmetric component and an asymmetric component (a tilted plane). The two tilt angle components are found that minimize the data scatter associated with the symmetric component. The most compelling example is the Furball test, an OS-variant for which the breakout time over the hemispherical observation surface is measured at many points using optical fibers. Unlike the OS test that looks in one (random) direction, we are able to construct OS-type data in the direction of maximum tilt, even though there are generally no fibers at that direction.

  13. Development of a handheld widefield hyperspectral imaging (HSI) sensor for standoff detection of explosive, chemical, and narcotic residues

    NASA Astrophysics Data System (ADS)

    Nelson, Matthew P.; Basta, Andrew; Patil, Raju; Klueva, Oksana; Treado, Patrick J.

    2013-05-01

    The utility of Hyper Spectral Imaging (HSI) passive chemical detection employing wide field, standoff imaging continues to be advanced in detection applications. With a drive for reduced SWaP (Size, Weight, and Power), increased speed of detection and sensitivity, developing a handheld platform that is robust and user-friendly increases the detection capabilities of the end user. In addition, easy to use handheld detectors could improve the effectiveness of locating and identifying threats while reducing risks to the individual. ChemImage Sensor Systems (CISS) has developed the HSI Aperio™ sensor for real time, wide area surveillance and standoff detection of explosives, chemical threats, and narcotics for use in both government and commercial contexts. Employing liquid crystal tunable filter technology, the HSI system has an intuitive user interface that produces automated detections and real-time display of threats with an end user created library of threat signatures that is easily updated allowing for new hazardous materials. Unlike existing detection technologies that often require close proximity for sensing and so endanger operators and costly equipment, the handheld sensor allows the individual operator to detect threats from a safe distance. Uses of the sensor include locating production facilities of illegal drugs or IEDs by identification of materials on surfaces such as walls, floors, doors, deposits on production tools and residue on individuals. In addition, the sensor can be used for longer-range standoff applications such as hasty checkpoint or vehicle inspection of residue materials on surfaces or bulk material identification. The CISS Aperio™ sensor has faster data collection, faster image processing, and increased detection capability compared to previous sensors.

  14. Proton radiography experiments on shocked high explosive products.

    SciTech Connect

    Ferm, Eric N.; Dennsion, Steve; Lopez, Robert; Prestridge, Kathy; Quintana, John P.; Espinoza, Camilo; King, Gary Hogan Nick; Merrill, Frank; Kevin Morley,; Morris, Christopher L.; Pazuchanic, Peter

    2003-07-22

    We studied the propagation of detonation waves and reflections of normal incident detonation waves in explosive products using the 800 MeV proton radiography facility at LANSCE. Using this system, we obtain seven to twenty-one radiographic images of each experiment. We have examined the experimental wave velocity and density of the materials ahead and behind of the shocks as inferred from radiographs and compare them to standard explosive equations of state. Finally we compare the experiments with calculations of the experiments using the MESA hydrodynamics code.

  15. High explosive corner turning performance and the LANL Mushroom test

    SciTech Connect

    Hill, L.G.; Seitz, W.L.; Forest, C.A.; Harry, H.H.

    1997-09-01

    The Mushroom test is designed to characterize the corner turning performance of a new generation of less insensitive booster explosives. The test is described in detail, and three corner turning figures-of-merit are examined using pure TATB (both Livermore`s Ultrafine and a Los Alamos research blend) and PBX9504 as examples.

  16. High explosive corner turning performance and the LANL mushroom test

    SciTech Connect

    Hill, L.G.; Seitz, W.L.; Forest, C.A.; Harry, H.H.

    1998-07-01

    The Mushroom test is designed to characterize the corner turning performance of a new generation of less sensitive booster explosives. The test is described in detail, and three corner turning figures-of-merit are examined using pure TATB (both Livermore{close_quote}s Ultrafine and a Los Alamos research blend) and PBX9504 as examples. {copyright} {ital 1998 American Institute of Physics.}

  17. Detonation Initiation of Heterogeneous Melt-Cast High Explosives

    NASA Astrophysics Data System (ADS)

    Chuzeville, Vincent; Baudin, Gerard; Lefrancois, Alexandre; Boulanger, Remi; Catoire, Laurent

    2015-06-01

    The melt-cast explosives' shock initiation mechanisms are less investigated than pressed and cast-cured ones. If the existence of hot-spots is widely recognized, their formation mechanism is not yet established. We study here two melt-cast explosives, NTO-TNT 60:40 and RDX-TNT 60:40 in order to establish a relation between the microstructure and the reaction rate using a two-phase model based on a ZND approach. Such a model requires the reaction rate, the equations of state of the unreacted phase and of the detonation products and an interaction model between the two phases to describe the reaction zone thermodynamics. The reaction rate law can be written in a factorized form including the number of initiation sites, the explosive's deflagration velocity around hot spots and a function depending on gas volume fraction produced by the deflagration front propagation. The deflagration velocity mainly depends on pressure and is determined from pop-plot tests using the hypothesis of the single curve build-up. This hypothesis has been verified for our two melt-cast explosives. The function depending on gas volume fraction is deduced from microstructural observations and from an analogy with the solid nucleation and growth theory. It has been established for deflagration fronts growing from grain's surface and a given initial grain size distribution. The model requires only a few parameters, calibrated thanks to an inversion method. A good agreement is obtained between experiments and numerical simulations.

  18. Safety Guidelines for Laser Illumination on Exposed High Explosives and Metals in Contact with High Explosives with Calculational Results

    SciTech Connect

    Benterou, J; Roeske, F; Wilkins, P; Carpenter, K H

    2002-04-17

    Experimental tests have been undertaken to determine safe levels of laser exposure on bare high explosive (HE) samples and on common metals used in intimate contact with HE. Laser light is often focused on bare HE and upon metals in contact with HE during alignment procedures and experimental metrology experiments. This paper looks at effects caused by focusing laser beams at high energy densities directly onto the surface of various bare HE samples. Laser energy densities (fluence) exceeding 19 kilowatts/cm{sup 2} using a 5-milliwatt, 670 nm, cw laser diode were generated by focusing the laser down to a spot size diameter of 4 microns. Upon careful inspection, no laser damage was observed in any of the HE samples illuminated at this fluence level. Direct laser exposure of metals directly contacting HE surfaces was also tested. Laser energy densities (fluence) varying from 188 Watts/cm{sup 2} to 12.7 KW/cm{sup 2} were generated using an 11-Watt, 532 nm frequency-doubled Nd:YAG cw laser with focal spot size diameters as small as 100 microns. These measurements look at the temperature rise of the surface of the metal in contact with HE when laser energy is incident on the opposite side of the metal. The temperature rise was experimentally measured as a function of incident laser power, spot size, metal composition and metal thickness. Numerical simulations were also performed to solve the two-dimensional heat flow problem for this experimental geometry. In order to simplify the numerical simulation to allow representation of a large number of physical cases, the equations used in the simulation are expressed in terms of dimensionless variables. The normalized numerical solutions are then compared to the various experimental configurations utilized. Calculations and experiment agree well over the range measured. Safety guidelines for alignment laser illumination upon bare HE are outlined.

  19. Insensitive explosive

    SciTech Connect

    Lee, Kien-yin; Storm, C.B.

    1991-12-31

    This invention relates to the field of chemistry and, more particularly, to explosives. This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36). It is desirable to use explosives in weapons and other applications which are less sensitive than the common explosives RDX, TNT, and HMX, since there have been catastrophic explosions of munitions which use these compounds. In preliminary characterization and sensitivity testing, it has been found that 3-amino-5-nitro-1,2,4-triazole (ANTA) is a promising insensitive high explosive. This report details the safety, production, and physical properties of ANTA.

  20. Building quantitative prediction models for tissue residue of two explosives compounds in earthworms from microarray gene expression data.

    PubMed

    Gong, Ping; Loh, Po-Ru; Barker, Natalie D; Tucker, George; Wang, Nan; Zhang, Chenhua; Escalon, B Lynn; Berger, Bonnie; Perkins, Edward J

    2012-01-01

    Soil contamination near munitions plants and testing grounds is a serious environmental concern that can result in the formation of tissue chemical residue in exposed animals. Quantitative prediction of tissue residue still represents a challenging task despite long-term interest and pursuit, as tissue residue formation is the result of many dynamic processes including uptake, transformation, and assimilation. The availability of high-dimensional microarray gene expression data presents a new opportunity for computational predictive modeling of tissue residue from changes in expression profile. Here we analyzed a 240-sample data set with measurements of transcriptomic-wide gene expression and tissue residue of two chemicals, 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), in the earthworm Eisenia fetida. We applied two different computational approaches, LASSO (Least Absolute Shrinkage and Selection Operator) and RF (Random Forest), to identify predictor genes and built predictive models. Each approach was tested alone and in combination with a prior variable selection procedure that involved the Wilcoxon rank-sum test and HOPACH (Hierarchical Ordered Partitioning And Collapsing Hybrid). Model evaluation results suggest that LASSO was the best performer of minimum complexity on the TNT data set, whereas the combined Wilcoxon-HOPACH-RF approach achieved the highest prediction accuracy on the RDX data set. Our models separately identified two small sets of ca. 30 predictor genes for RDX and TNT. We have demonstrated that both LASSO and RF are powerful tools for quantitative prediction of tissue residue. They also leave more unknown than explained, however, allowing room for improvement with other computational methods and extension to mixture contamination scenarios. PMID:21776976

  1. Phenomenological model for infrared emissions from high-explosive detonation fireballs

    NASA Astrophysics Data System (ADS)

    Gross, Kevin C.

    Prior to this work, a phenomenological description of mid-wave infrared (MWIR) emissions from high-explosive (HE) detonation fireballs did not exist, hampering efforts to classify the type and size of HEs from their electro-optical signatures. In recent field tests, temporally-resolved infrared spectra (0.05 ≤ Delta t ≤ 0.12 s, 2 ≤ Deltanu ≤ 8 cm -1) were collected via a Fourier-transform spectrometer (FTS) from the detonation fireballs of two types of conventional military munitions (CMM) as well as uncased TNT and four types of enhanced novel explosives (ENEs). The FTS data is not appreciably corrupted by artifacts due to scene changes resulting from the fast transient events. The CMM spectra are dominated by continuum emission, and a single-temperature Planckian distribution, modified for atmospheric attenuation, captures most of the variation in the data. Fitted CMM temperatures are well described by an exponential decay to ambient at an approximate rate of 0.8 s-1. A two-temperature fit to CMM spectra improved results, suggesting variations in the temperature field are important. Some evidence of selective emission is identified by systematic patterns in the fit residuals. The behavior of these systematic residuals affords a distinction between the two types of CMMs studied. The uncased TNT and ENE spectra appear strongly influenced by both continuum and selective emission. For the purpose of dimensionality reduction, a physics-based spectral model is developed consisting of seven parameters---fireball size, temperature, particulate absorption coefficient, and gas concentrations for H2O, CO2, CO, and HCl. Fitting this model to the observed MWIR spectra affords a compact, high-fidelity representation with physically-constrained features that correlate with both the type and weight of the HE. For example, the hydrogen-to-carbon ratio (R) estimated from the fitted concentrations separates the TNT and ENE events. Spectrally-determined R values are somewhat

  2. Capillary-driven microfluidic paper-based analytical devices for lab on a chip screening of explosive residues in soil.

    PubMed

    Ueland, Maiken; Blanes, Lucas; Taudte, Regina V; Stuart, Barbara H; Cole, Nerida; Willis, Peter; Roux, Claude; Doble, Philip

    2016-03-01

    A novel microfluidic paper-based analytical device (μPAD) was designed to filter, extract, and pre-concentrate explosives from soil for direct analysis by a lab on a chip (LOC) device. The explosives were extracted via immersion of wax-printed μPADs directly into methanol soil suspensions for 10min, whereby dissolved explosives travelled upwards into the μPAD circular sampling reservoir. A chad was punched from the sampling reservoir and inserted into a LOC well containing the separation buffer for direct analysis, avoiding any further extraction step. Eight target explosives were separated and identified by fluorescence quenching. The minimum detectable amounts for all eight explosives were between 1.4 and 5.6ng with recoveries ranging from 53-82% from the paper chad, and 12-40% from soil. This method provides a robust and simple extraction method for rapid identification of explosives in complex soil samples. PMID:26850317

  3. Biodegradation of high explosives on granular activated carbon [GAC]: Enhanced desorption of high explosives from GAC -- Batch studies

    SciTech Connect

    Morley, M.C.; Speitel, G.E. Jr.

    1999-03-01

    Adsorption to GAC is an effective method for removing high explosives (HE) compounds from water, but no permanent treatment is achieved. Bioregeneration, which treats adsorbed contaminants by desorption and biodegradation, is being developed as a method for reducing GAC usage rates and permanently degrading RDX and HMX. Because desorption is often the limiting mass transfer mechanism in bioregeneration systems, several methods for increasing the rate and extent of desorption of RDX and HMX are being studied. These include use of cosolvents (methanol and ethanol), surfactants (both anionic and nonionic), and {beta}- and {gamma}-cyclodextrins. Batch experiments to characterize the desorption of these HEs from GAC have been completed using Northwestern LB-830, the GAC being used at Pantex. Over a total of 11 days of desorption, about 3% of the adsorbed RDX was desorbed from the GAC using buffered water as the desorption fluid. In comparison, about 96% of the RDX was extracted from the GAC by acetonitrile over the same desorption period. Ethanol and methanol were both effective in desorbing RDX and HMX; higher alcohol concentrations were able to desorb more HE from the GAC. Surfactants varied widely in their abilities to enhance desorption of HEs. The most effective surfactant that was studied was sodium dodecyl sulfate (SDS), which desorbed 56.4% of the adsorbed RDX at a concentration of 500 mg SDS/L. The cyclodextrins that were used were marginally more effective than water. Continuous-flow column tests are underway for further testing the most promising of these methods. These results will be compared to column experiments that have been completed under baseline conditions (using buffered water as the desorption fluid). Results of this research will support modeling and design of further desorption and bioregeneration experiments.

  4. High explosive safety manual. Final technical report, September 1978-May 1980

    SciTech Connect

    Albaugh, L.R.; McBride, D.A.

    1980-06-01

    A Safety Manual for High Explosive Processing, Handling, and Testing has been prepared for the Department of Energy. Background on the preparation and recommendations for manual implementation and augmentation are provided. The Manual is provided as a separate document.

  5. Conversion of direct process high-boiling residue to monosilanes

    DOEpatents

    Brinson, Jonathan Ashley; Crum, Bruce Robert; Jarvis, Jr., Robert Frank

    2000-01-01

    A process for the production of monosilanes from the high-boiling residue resulting from the reaction of hydrogen chloride with silicon metalloid in a process typically referred to as the "direct process." The process comprises contacting a high-boiling residue resulting from the reaction of hydrogen chloride and silicon metalloid, with hydrogen gas in the presence of a catalytic amount of aluminum trichloride effective in promoting conversion of the high-boiling residue to monosilanes. The present process results in conversion of the high-boiling residue to monosilanes. At least a portion of the aluminum trichloride catalyst required for conduct of the process may be formed in situ during conduct of the direct process and isolation of the high-boiling residue.

  6. Drill-pipe severing tool with high-temperature explosive

    SciTech Connect

    Koczan, S.P.; Patterson, W.W.; Rochester. R.H.

    1982-08-01

    A special-purpose borehole explosive tool designed to meet a need of the Los Alamos National laboratory Hot Dry Rock (HDR) Geothermal Energy Development Program is described. This tool's particular purpose is to sever stuck drill pipe in deep (> 4500 m), hot (> 320/sup 0/C), water-filled wellbores. No commercial severing tools are known to us that can be operated at temperatures above 260/sup 0/C.

  7. IMAGING HIGH SPEED PARTICLES IN EXPLOSIVE DRIVEN BLAST WAVES

    SciTech Connect

    Jenkins, C. M.; Horie, Y.; Ripley, R. C.; Wu, C.-Y.

    2009-12-28

    This research describes a new application of a commercially available particle image velocimetry (PIV) instrument adapted for imaging particles in a blast wave. Powder was dispersed through the PIV light sheet using a right circular cylindrical charge containing aluminum powder filled in the annular space between the explosive core and exterior paper tube wall of the charge. Images acquired from each shot showed particle agglomeration and unique structures with the smaller particle diameters having developed structured appearances.

  8. Explosion of heterogeneous water droplet in a high-temperature gaseous region

    NASA Astrophysics Data System (ADS)

    Piskunov, M. V.; Shcherbinina, A. A.

    2015-11-01

    Using high-speed video recording tools (up to 105 frames per second) and «TEMA Automotive» and «Phantom Camera Control» software packages the experimental features of explosive disintegration, boiling and evaporation of water droplets with comparably sized solid inclusions heated in high-temperature (more than 650 K) gaseous region were determined. The necessary and sufficient conditions of explosive vapor formation achievement with the next heterogeneous water droplet disintegration were found.

  9. Particle size analysis of prepared solutions and fingerprint deposits of high explosive materials

    SciTech Connect

    Carmack, W.J.; Hembree, P.B.

    1998-03-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) managed and operated by Lockheed Martin Idaho Technologies Company (LMITCO) was tasked via the Federal Aviation Administration (FAA) and US Department of Energy (DOE) to conduct various studies involving the detection and measurement of explosive materials and their associated residues. This report details the results of an investigation to determine the particle size characteristics of the explosive materials used in the design, development, and testing of trace explosives detection systems. These materials, in the form of water suspensions of plastic explosives, are used to provide a quantitative means of monitoring the performance characteristics of the detection systems. The purpose of this investigation is to provide data that allows a comparison between the particles deposited using the suspension standards and the particles deposited from fingerprints. This information may support the development of quality control aids, measurement methods, or performance criteria specifications for the use of trace explosives detection systems. For this report, particle size analyses were completed on explosives standard suspensions/solutions for composition C-4, Semtex-H, and Detasheet and fingerprints for C-4, Detasheet, and pentolite. Because of the difficulty in collecting microscopic images of the particles in the suspensions from test protocol surfaces, this paper discusses the characteristics of the particles as they are found on metal, glass, and paper. The results of the particle characterization analyses indicate that the water suspensions contain particulate composed of binder materials and dissolved portions of the explosive compounds. Upon drying of the water suspensions, significant particle nucleation and growth is observed. The nucleated particulate is comparable to the particulate deposited by fingerprints.

  10. Characterization of high-explosive initiation and safety at Los Alamos

    SciTech Connect

    McAfee, J.M.

    1994-10-01

    The Chapman-Jouget and ZND models of steady detonation have proved most useful for engineering estimation of the propagation of near-planar, steady detonation in short-reaction-zone explosives. However, even in well characterized systems, the purposeful initiation of detonation is not described by these models. The highly divergent and microscopic nature of point initiation require discerning experiments, modeling, and theoretical analysis. Recently, safety considerations in complex or damaged systems, possibly containing long-reaction-zone (insensitive) high explosives, have dominated the author`s thinking. These situations are rarely planar or steady, the physical state of the explosive may not be easily characterized, and there is a wide range of potential stimuli. The high-explosive reaction may range from none, to deflagration, to partial detonation, or to full detonation. Techniques and data applicable to estimating the level of response are needed.

  11. An explicit model of expanding cylindrical shells subjected to high explosive detonations

    SciTech Connect

    Martineau, R.L.; Prime, M.B.; Anderson, C.A.; Smith, F.W.

    1999-04-01

    A viscoplastic constitutive model was formulated to model the high strain-rate expansion of thin cylindrical shells subjected to internal explosive detonations. This model provides insight into the development of plastic instabilities, which occur on the surface of the shells prior to failure. The effects of shock heating and damage in the form of microvoid nucleation, growth, and coalescence were incorporated using the Johnson-Cook strength model with the Mie-Grueneisen equation of state and a modified Gurson yield surface. This model was implemented into ABAQUS/Explicit as a user material subroutine. A cylindrical copper shell was modeled using both axisymmetric and plane strain elements. The high explosive material inside of the cylinder was simulated using the high explosive burn model in ABAQUS/Explicit. Two experiments were conducted involving explosive-filled, copper cylinders and good agreement was obtained between the numerical results and experimental data.

  12. EVALUATING THE USE OF SNOW-COVERED RANGES TO ESTIMATE THE EXPLOSIVES RESIDUES THAT RESULT FROM DETONATION OF ARMY MUNITIONS

    EPA Science Inventory

    Estimating the amounts of residues remaining after munitions detonate is complicated by the presence of residues from previous detonations and the difficulty in easily obtaining adequately sized samples to overcome spatial heterogeneity in residue deposition. This study was cond...

  13. Detection of High Explosives Using Reflection Absorption Infrared Spectroscopy with Fiber Coupled Grazing Angle Probe/FTIR

    NASA Astrophysics Data System (ADS)

    Primera-Pedrozo, Oliva M.; Soto-Feliciano, Yadira M.; Pacheco-Londoño, Leonardo C.; Hernández-Rivera, Samuel P.

    2009-06-01

    Fiber Optic Coupled Reflection/Absorption Infrared Spectroscopy (RAIRS) has been investigated as a potential technique for developing methodologies of detection and quantification of explosive residues on metallic surfaces. TNT, DNT, HMX, PETN, and Tetryl were detected at loading concentrations less than 400 ng/cm2. Data were analyzed using Chemometrics statistical analysis routines. In particular, partial least squares multivariate analysis (PLS) was used for quantification studies. Peak areas were also used for data analysis to compare with linear multivariate analysis. The measurements resulted in intense absorption bands in the fingerprint region of the infrared spectrum that were used to quantify the target threat chemicals and to calculate the limit of detection for each compound. Micro-RAIRS vibrational imaging was also used for characterization of the distribution and form of layers of explosives deposited on stainless steel sheets. The degree of homogeneity depended strongly on the method of deposition. The images were generated by calculating the area under vibrational signals of 15 μm × 15 μm grids with a separation of 15 μm. Histograms of the maps were generated and the homogeneity was evaluated by using standard deviations, mean kurtosis, skewness, and moments of distributions obtained. Methanol solutions of High Explosives (HE) resulted in the optimum distributions on the stainless steel surfaces tested and therefore, Methanol selected as the preferred solvent for the Fiber Optics Coupled-RAIRS experiments.

  14. Hot-spot contributions in shocked high explosives from mesoscale ignition models

    NASA Astrophysics Data System (ADS)

    Levesque, G.; Vitello, P.; Howard, W. M.

    2013-06-01

    High explosive performance and sensitivity is strongly related to the mesoscale defect densities. Bracketing the population of mesoscale hot spots that are active in the shocked ignition of explosives is important for the development of predictive reactive flow models. By coupling a multiphysics-capable hydrodynamics code (ale3d) with a chemical kinetics solver (cheetah), we can parametrically analyze different pore sizes undergoing collapse in high pressure shock conditions with evolving physical parameter fields. Implementing first-principles based decomposition kinetics, burning hot spots are monitored, and the regimes of pore sizes that contribute significantly to burnt mass faction and those that survive thermal conduction on the time scales of ignition are elucidated. Comparisons are drawn between the thermal explosion theory and the multiphysics models for the determination of nominal pore sizes that burn significantly during ignition for the explosive 1,3,5-triamino-2,4,6-trinitrobenzene.

  15. Role of explosive instabilities in high-β disruptions in tokamaks

    NASA Astrophysics Data System (ADS)

    Aydemir, A. Y.; Lee, H. H.; Lee, S. G.; Seol, J.; Park, B. H.; In, Y. K.

    2016-05-01

    Intrinsically explosive growth of a ballooning finger is demonstrated in nonlinear magnetohydrodynamic calculations of high-β disruptions in tokamaks. The explosive finger is formed by an ideally unstable n  =  1 mode, dominated by an m/n  =  2/1 component. The quadrupole geometry of the 2/1 perturbed pressure field provides a generic mechanism for the formation of the initial ballooning finger and its subsequent transition from exponential to explosive growth, without relying on secondary processes. The explosive ejection of the hot plasma from the core and stochastization of the magnetic field occur on Alfvénic time scales, accounting for the extremely fast growth of the precursor oscillations and the rapidity of the thermal quench in some high-β disruptions.

  16. Invited Article: Quantitative imaging of explosions with high-speed cameras.

    PubMed

    McNesby, Kevin L; Homan, Barrie E; Benjamin, Richard A; Boyle, Vincent M; Densmore, John M; Biss, Matthew M

    2016-05-01

    The techniques presented in this paper allow for mapping of temperature, pressure, chemical species, and energy deposition during and following detonations of explosives, using high speed cameras as the main diagnostic tool. This work provides measurement in the explosive near to far-field (0-500 charge diameters) of surface temperatures, peak air-shock pressures, some chemical species signatures, shock energy deposition, and air shock formation. PMID:27250366

  17. Pressure loading of aluminum and quartz using spray deposited light-initiated high explosive

    SciTech Connect

    Benham, R. A.

    1980-02-01

    A series of experiments was conducted for the purpose of evaluating the impulsive pressure loading generated at a material surface by the detonation of light-initiated high explosive on that surface. The explosive was sprayed and then detonated directly on both carbon and quartz pressure transducers. The output was recorded to allow determination of the characteristics of the pressure loading, as well as to evaluate the variability of this loading.

  18. Characterization of Detonation Soot Produced During Steady and Overdriven Conditions for Three High Explosive Formulations

    NASA Astrophysics Data System (ADS)

    Podlesak, David; Amato, Ronald; Dattelbaum, Dana; Firestone, Millicent; Gustavsen, Richard; Huber, Rachel; Ringstrand, Bryan

    2015-06-01

    The detonation of high explosives (HE) produces a dense fluid of molecular gases and solid carbon. The solid detonation carbon contains various carbon allotropes such as detonation nanodiamonds, ``onion-like'' carbon, graphite and amorphous carbon, with the formation of the different forms dependent upon pressure, temperature and the environmental conditions of the detonation. We have collected solid carbon residues from controlled detonations of three HE formulations (Composition B-3, PBX 9501, and PBX 9502). Soot was collected from experiments designed to produce both steady and overdriven conditions, and from detonations in both an ambient (air) atmosphere and in an inert Ar atmosphere. Structural studies to glean the features of the solid carbon products have been performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Raman spectroscopy, small-angle X-ray scattering (SAXS), and X-Ray Pair Distribution Function measurements (PDF). Bulk soot was also analyzed for elemental and isotopic compositions. We will discuss differences in the structure and composition of the detonation carbon as a function of formulation, detonation conditions, and the surrounding atmosphere.

  19. A simple approach for determining detonation velocity of high explosive at any loading density.

    PubMed

    Keshavarz, Mohammad Hossein

    2005-05-20

    A simple empirical relationship is introduced between detonation velocity at any loading density and chemical composition of high explosive as well as its gas phase heat of formation, which is calculated by group additivity rules. The present work may be applied to any explosive that contains the elements of carbon, hydrogen, nitrogen and oxygen with no difficulties. The new correlation can easily be applied for determining detonation velocity of explosives with loading densities less than 1g/cm3 as well as greater than 1g/cm3. Calculated detonation velocities by this procedure for both pure and explosive formulations show good agreement with respect to measured detonation velocity over a wide range of loading density. PMID:15885403

  20. Continuous steam explosion

    SciTech Connect

    Taylor, J.D.; Yu, E.K.C.

    1995-02-01

    StakeTech has focused on developing steam explosion on a commercial basis. The company essentially a biomass conversion company dealing with cellulosic biomass such as wood, crop residues and, more recently, wastepaper and municipal solid waste (MSW). They are faced with a tremendous opportunity to develop uses for the 50% of biomass that is currently wasted. The StakeTech steam explosion process is able to break the bonds using only high-pressure steam with no chemical additives. The continuous StakeTech System now has been installed in five countries and has proved effective in processing a wide variety of raw materials including wood chips, straw, sugarcane bagasse, and waste paper. End-use applications range from specialty chemicals to large-volume agricultural products. The increase of development activities in steam explosion should lead to expanded end-use applications, and acceptance of the technology by industry should accelerate in the years to come.

  1. Computer code to predict the heat of explosion of high energy materials.

    PubMed

    Muthurajan, H; Sivabalan, R; Pon Saravanan, N; Talawar, M B

    2009-01-30

    The computational approach to the thermochemical changes involved in the process of explosion of a high energy materials (HEMs) vis-à-vis its molecular structure aids a HEMs chemist/engineers to predict the important thermodynamic parameters such as heat of explosion of the HEMs. Such a computer-aided design will be useful in predicting the performance of a given HEM as well as in conceiving futuristic high energy molecules that have significant potential in the field of explosives and propellants. The software code viz., LOTUSES developed by authors predicts various characteristics of HEMs such as explosion products including balanced explosion reactions, density of HEMs, velocity of detonation, CJ pressure, etc. The new computational approach described in this paper allows the prediction of heat of explosion (DeltaH(e)) without any experimental data for different HEMs, which are comparable with experimental results reported in literature. The new algorithm which does not require any complex input parameter is incorporated in LOTUSES (version 1.5) and the results are presented in this paper. The linear regression analysis of all data point yields the correlation coefficient R(2)=0.9721 with a linear equation y=0.9262x+101.45. The correlation coefficient value 0.9721 reveals that the computed values are in good agreement with experimental values and useful for rapid hazard assessment of energetic materials. PMID:18513863

  2. Measurement of trace explosive residues in a surrogate operational environment: implications for tactical use of chemical sensing in C-IED operations.

    PubMed

    Kunz, Roderick R; Gregory, Kerin Clow; Hardy, Dennis; Oyler, Jonathan; Ostazeski, Stanley A; Fountain, Augustus Way

    2009-09-01

    A campaign to measure the amount of trace explosive residues in an operational military environment was conducted on May 27-31, 2007, at the National Training Center at Fort Irwin, CA, USA. The objectives of this campaign were to develop the methods needed to collect and analyze samples from tactical military settings, to use the data obtained to determine what the trace explosive signatures suggest about the potential capabilities of chemical-based means to detect IEDs, and, finally, to present a framework whereby a sound understanding of the signature science can be used to guide development of new sensing technologies and sensor concepts of operation. Through our use of combined background and threat signature data, we have performed statistical analyses to estimate upper limits of notional sensor performance that is limited only by the spatial correlation of the signature chemicals to the threats of interest. PMID:19340417

  3. A novel method for the measurement of the von Neumann spike in detonating high explosives

    NASA Astrophysics Data System (ADS)

    Sollier, A.; Bouyer, V.; Hébert, P.; Doucet, M.

    2016-06-01

    We present detonation wave profiles measured in T2 (97 wt. % TATB) and TX1 (52 wt. % TATB and 45 wt. % HMX) high explosives. The experiments consisted in initiating a detonation wave in a 15 mm diameter cylinder of explosive using an explosive wire detonator and an explosive booster. Free surface velocity wave profiles were measured at the explosive/air interface using a Photon Doppler Velocimetry system. We demonstrate that a comparison of these free surface wave profiles with those measured at explosive/window interfaces in similar conditions allows to bracket the von Neumann spike in a narrow range. For T2, our measurements show that the spike pressure lies between 35.9 and 40.1 GPa, whereas for TX1, it lies between 42.3 and 47.0 GPa. The numerical simulations performed in support to these measurements show that they can be used to calibrate reactive burn models and also to check the accuracy of the detonation products equation of state at low pressure.

  4. On the high fidelity simulation of chemical explosions and their interaction with solid particle clouds

    NASA Astrophysics Data System (ADS)

    Balakrishnan, Kaushik

    The flow field behind chemical explosions in multiphase environments is investigated using a robust, state-of-the-art simulation strategy that accounts for the thermodynamics, gas dynamics and fluid mechanics of relevance to the problem. Focus is laid on the investigation of blast wave propagation, growth of hydrodynamic instabilities behind explosive blasts, the mixing aspects behind explosions, the effects of afterburn and its quantification, and the role played by solid particles in these phenomena. In particular, the confluence and interplay of these different physical phenomena are explored from a fundamental perspective, and applied to the problem of chemical explosions. A solid phase solver suited for the study of high-speed, two-phase flows has been developed and validated. This solver accounts for the inter-phase mass, momentum and energy transfer through empirical laws, and ensures two-way coupling between the two phases, viz. solid particles and gas. For dense flow fields, i.e., when the solid volume fraction becomes non-negligible (˜60%), the finite volume method with a Godunov type shock-capturing scheme requires modifications to account for volume fraction gradients during the computation of cell interface gas fluxes. To this end, the simulation methodology is extended with the formulation of an Eulerian gas, Lagrangian solid approach, thereby ensuring that the so developed two-phase simulation strategy can be applied for both flow conditions, dilute and dense alike. Moreover, under dense loading conditions the solid particles inevitably collide, which is accounted for in the current research effort with the use of an empirical collision/contact model from literature. Furthermore, the post-detonation flow field consists of gases under extreme temperature and pressure conditions, necessitating the use of real gas equations of state in the multiphase model. This overall simulation strategy is then extended to the investigation of chemical explosions in

  5. Spectral and angular dependence of mid-infrared diffuse scattering from explosives residues for standoff detection using external cavity quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Suter, Jonathan D.; Bernacki, Bruce; Phillips, Mark C.

    2012-09-01

    We present a study of the spectral and angular dependence of scattered mid-infrared light from surfaces coated with explosives residues (TNT, RDX, and tetryl) detected at a 2 m standoff distance. An external cavity quantum cascade laser provided tunable illumination between 7 and 8 μm. Important differences were identified in the spectral features between specular reflection and diffuse scattering which will impact most practical testing scenarios and complicate material identification. We discuss some of the factors influencing the dependence of observed spectra on the experimental geometry.

  6. Spectral and angular dependence of mid-infrared diffuse scattering from explosives residues for standoff detection using external cavity quantum cascade lasers

    SciTech Connect

    Suter, Jonathan D.; Bernacki, Bruce E.; Phillips, Mark C.

    2012-09-01

    We present a study of the spectral and angular dependence of scattered mid-infrared light from surfaces coated with explosives residues (TNT, RDX, and tetryl) detected at a 2 meter standoff distance. An external cavity quantum cascade laser provided tunable illumination between 7 and 8 µm. Important differences were identified in the spectral features between specular reflection and diffuse scattering which will impact most practical testing scenarios and complicate material identification. We discuss some of the factors influencing the dependence of observed spectra on the experimental geometry.

  7. In-field assessment of chemical high explosives using immunoassay techniques

    SciTech Connect

    Hardy, D.J.; Crossley, D.B.; O`Connell, M.S.

    1995-12-31

    Base realignment and weapons complex reconfiguration have prompted closure of former military related properties. As a result, chemical high explosives in environmental media are encountered with greater frequency during accelerated site characterization activities. The DOE`s Pantex nuclear weapons production/disassembly facility in Amarillo, Texas has observed nitroaromatic and nitramine compounds in soil and groundwater. Recognizing that phases characterization programs are time consuming and expensive, Pantex has employed compound specific immunoassay screening techniques to semi-quantitatively assess high explosive contamination in environmental media. As a result of using immunoassay techniques at over 500 sample locations, Pantex has achieved significant benefits corollary to reduced analytical expenses and timeframes, waste generation and management expenditures, field mobilization, and site characterization timeframes. Pantex Plant concludes that the use of immunoassay field screening of samples for chemical high explosives results in accelerated site characterization at a decreased expense while maintaining quality protocols and worker protection.

  8. Identification of high explosive RDX using terahertz imaging and spectral fingerprints

    NASA Astrophysics Data System (ADS)

    Liu, Jia; Fan, Wen-Hui; Chen, Xu; Xie, Jun

    2016-01-01

    We experimentally investigated the spectral fingerprints of high explosive cyclo-1,3,5- trimethylene-2,4,6-trinitramine (RDX) in terahertz frequency region. A home-made terahertz time-domain spectroscopy ranging from 0.2 THz∼ 3.4 THz was deployed. Furthermore, two sample pellets (RDX pellet and polyethylene pellet), which were concealed in an opaque envelop, could be identified by using terahertz pulse imaging system. For the purpose of distinguishing the RDX between two pellets, we further calculated the THz frequency -domain map using its spectral fingerprints. It is demonstrated that the high explosive RDX could similarly be identified using terahertz frequency-domain imaging.

  9. Engineering High-Fidelity Residue Separations for Selective Harvest

    SciTech Connect

    Kevin L. Kenney; Christopher T. Wright; Reed L. Hoskinson; J. Rochard Hess; David J. Muth, Jr.

    2006-07-01

    Composition and pretreatment studies of corn stover and wheat stover anatomical fractions clearly show that some corn and wheat stover anatomical fractions are of higher value than others as a biofeedstock. This premise, along with soil sustainability and erosion control concerns, provides the motivation for the selective harvest concept for separating and collecting the higher value residue fractions in a combine during grain harvest. This study recognizes the analysis of anatomical fractions as theoretical feedstock quality targets, but not as practical targets for developing selective harvest technologies. Rather, practical quality targets were established that identified the residue separation requirements of a selective harvest combine. Data are presented that shows that a current grain combine is not capable of achieving the fidelity of residue fractionation established by the performance targets. However, using a virtual engineering approach, based on an understanding of the fluid dynamics of the air stream separation, the separation fidelity can be significantly improved without significant changes to the harvester design. A virtual engineering model of a grain combine was developed and used to perform simulations of the residue separator performance. The engineered residue separator was then built into a selective harvest test combine, and tests performed to evaluate the separation fidelity. Field tests were run both with and without the residue separator installed in the test combine, and the chaff and straw residue streams were collected during harvest of Challis soft white spring wheat. The separation fidelity accomplished both with and without the residue separator was quantified by laboratory screening analysis. The screening results showed that the engineered baffle separator did a remarkable job of effecting high-fidelity separation of the straw and chaff residue streams, improving the chaff stream purity and increasing the straw stream yield.

  10. A verification and validation effort for high explosives at Los Alamos National Lab (u)

    SciTech Connect

    Scovel, Christina A; Menikoff, Ralph S

    2009-01-01

    We have started a project to verify and validate ASC codes used to simulate detonation waves in high explosives. Since there are no non-trivial analytic solutions, we are going to compare simulated results with experimental data that cover a wide range of explosive phenomena. The intent is to compare both different codes and different high explosives (HE) models. The first step is to test the products equation of state used for the HE models, For this purpose, the cylinder test, flyer plate and plate-push experiments are being used. These experiments sample different regimes in thermodynamic phase space: the CJ isentrope for the cylinder tests, the isentrope behind an overdriven detonation wave for the flyer plate experiment, and expansion following a reflected CJ detonation for the plate-push experiment, which is sensitive to the Gruneisen coefficient. The results of our findings for PBX 9501 are presented here.

  11. Composting of soils/sediments and sludges containing toxic organics including high energy explosives. Final report

    SciTech Connect

    Doyle, R.C.; Kitchens, J.F.

    1993-07-01

    Laboratory and pilot-scale experimentation were conducted to evaluate composting as an on-site treatment technology to remediate soils contaminated with hazardous waste at DOE`s PANTEX Plant. Suspected contaminated sites within the PANTEX Plant were sampled and analyzed for explosives, other organics, and inorganic wastes. Soils in drainage ditches and playas at PANTEX Plant were found to be contaminated with low levels of explosives (including RDX, HMX, PETN and TATB). Additional sites previously used for solvent disposal were heavily contaminated with solvents and transformation products of the solvent, as well as explosives and by-products of explosives. Laboratory studies were conducted using {sup 14}C-labeled explosives and {sup 14}C-labeled diacetone alcohol contaminated soil loaded into horse manure/hay composts at three rates: 20, 30, and 40%(W/W). The composts were incubated for six weeks at approximately 60{degree}C with continuous aeration. All explosives degraded rapidly and were reduced to below detection limits within 3 weeks in the laboratory studies. {sup 14}C-degradates from {sup 14}C-RDX, {sup 14}C-HMX and {sup 14}C-TATB were largely limited to {sup 14}CO{sub 2} and unextracted residue in the compost. Volatile and non-volatile {sup 14}C-degradates were found to result from {sup 14}C-PETN breakdown, but these compounds were not identified. {sup 14}C-diacetone alcohol concentrations were significantly reduced during composting. However, most of the radioactivity was volatilized from the compost as non-{sup 14}CO{sub 2} degradates or as {sup 14}C-diacetone alcohol. Pilot scale composts loaded with explosives contaminated soil at 30% (W/W) with intermittent aeration were monitored over six weeks. Data from the pilot-scale study generally was in agreement with the laboratory studies. However, the {sup 14}C-labeled TATB degraded much faster than the unlabeled TATB. Some formulations of TATB may be more resistant to composting activity than others.

  12. Full-scale high-speed schlieren imaging of explosions and gunshots

    NASA Astrophysics Data System (ADS)

    Settles, Gary S.; Grumstrup, Torben P.; Dodson, Lori J.; Miller, J. D.; Gatto, Joseph A.

    2005-03-01

    High-speed imaging and cinematography are important in research on explosions, firearms, and homeland security. Much can be learned from imaging the motion of shock waves generated by such explosive events. However, the required optical equipment is generally not available for such research due to the small aperture and delicacy of the optics and the expense and expertise required to implement high-speed optical methods. For example, previous aircraft hardening experiments involving explosions aboard full-scale aircraft lacked optical shock imaging, even though such imaging is the principal tool of explosion and shock wave research. Here, experiments are reported using the Penn State Full-Scale Schlieren System, a lens-and-grid-type optical system with a very large field-of-view. High-speed images are captured by photography using an electronic flash and by a new high-speed digital video camera. These experiments cover a field-of-view of 2x3 m at frame rates up to 30 kHz. Our previous high-speed schlieren cinematography experiments on aircraft hardening used a traditional drum camera and photographic film. A stark contrast in utility is found between that technology and the all-digital high-speed videography featured in this paper.

  13. High explosive spot test analyses of samples from Operable Unit (OU) 1111

    SciTech Connect

    McRae, D.; Haywood, W.; Powell, J.; Harris, B.

    1995-01-01

    A preliminary evaluation has been completed of environmental contaminants at selected sites within the Group DX-10 (formally Group M-7) area. Soil samples taken from specific locations at this detonator facility were analyzed for harmful metals and screened for explosives. A sanitary outflow, a burn pit, a pentaerythritol tetranitrate (PETN) production outflow field, an active firing chamber, an inactive firing chamber, and a leach field were sampled. Energy dispersive x-ray fluorescence (EDXRF) was used to obtain semi-quantitative concentrations of metals in the soil. Two field spot-test kits for explosives were used to assess the presence of energetic materials in the soil and in items found at the areas tested. PETN is the major explosive in detonators manufactured and destroyed at Los Alamos. No measurable amounts of PETN or other explosives were detected in the soil, but items taken from the burn area and a high-energy explosive (HE)/chemical sump were contaminated. The concentrations of lead, mercury, and uranium are given.

  14. A Statistical Hot Spot Reactive Flow Model for Shock Initiation and Detonation of Solid High Explosives

    SciTech Connect

    Nichols, A L; Tarver, C M

    2002-07-01

    A statistical hot spot reactive flow model for shock initiation and detonation of solid high explosives developed in the ALE3D hydrodynamic computer code is presented. This model is intended to evolve into a physically correct description of the physical and chemical mechanisms that control the onset of shock initiation via hotspot formation, the growth (01 failure to grow) of these hotspots into the surrounding explosive particles, the rapid transition to detonation, and self-sustaining detonation. Mesoscale modeling of the shock compression and temperature dependent chemical decomposition of individual explosive particles are currently yielding accurate predictions of hot spot formation and the subsequent growth (or failure) of these hotspot reactions in the surrounding grains. For two- and three-dimensional simulations of larger scale explosive charges, a statistical hotspot model that averages over thousands of individual hotspot dimensions and temperatures and then allows exothermic chemical reactions to grow (or fail to grow) due to thermal conduction is required. This paper outlines a first approach to constructing a probabilistic hot spot formulation based on the number density of potential hotspot sites. These hotspots can then either ignite or die out if they do not exceed certain ignition criteria, which are based on physical properties of the explosive particles. The growing hot spots spread at burn velocities given by experimentally determined deflagration velocity versus pressure relationships. The mathematics and assumptions involved in formulating the model and practical examples of its usefulness are given.

  15. Evaluation of different sampling media for their potential use as a combined swab for the collection of both organic and inorganic explosive residues.

    PubMed

    Song-im, Nopporn; Benson, Sarah; Lennard, Chris

    2012-10-10

    Commercially available skin cleansing alcohol wipes and conventional swabs were investigated for their use as a universal sampling medium for the simultaneous collection of both organic and inorganic explosive residues. Six compounds with the potential to be encountered in casework [pentaerythritol tetranitrate (PETN), 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), triacetone triperoxide (TATP), ammonium nitrate, and sodium chlorate] were selected as representative target compounds. Quantities of these target compounds were deposited on four different substrates (glass, plastic, aluminium foil and laminate). Two chosen alcohol wipes demonstrated better overall performance in the recovery of both the organic and inorganic representative compounds from each of the test surfaces compared to the results obtained using conventional cotton and polyester swabs, pre-moistened with various solvents, and a direct methanol wash (used as a control). Results obtained using dry cotton swabs indicated that it was not an effective swabbing system for the collection of both organic and inorganic explosive residues on common substrates. PMID:22658743

  16. Extrusion cast explosive

    DOEpatents

    Scribner, Kenneth J.

    1985-01-01

    Improved, multiphase, high performance, high energy, extrusion cast explosive compositions, comprising, a crystalline explosive material; an energetic liquid plasticizer; a urethane prepolymer, comprising a blend of polyvinyl formal, and polycaprolactone; a polyfunctional isocyanate; and a catalyst are disclosed. These new explosive compositions exhibit higher explosive content, a smooth detonation front, excellent stability over long periods of storage, and lower sensitivity to mechanical stimulants.

  17. Optically detonated explosive device

    NASA Technical Reports Server (NTRS)

    Yang, L. C.; Menichelli, V. J. (Inventor)

    1974-01-01

    A technique and apparatus for optically detonating insensitive high explosives, is disclosed. An explosive device is formed by containing high explosive material in a house having a transparent window. A thin metallic film is provided on the interior surface of the window and maintained in contact with the high explosive. A laser pulse provided by a Q-switched laser is focussed on the window to vaporize the metallic film and thereby create a shock wave which detonates the high explosive. Explosive devices may be concurrently or sequentially detonated by employing a fiber optic bundle to transmit the laser pulse to each of the several individual explosive devices.

  18. Mesoscopic simulations of shock-to-detonation transition in reactive liquid high explosive

    NASA Astrophysics Data System (ADS)

    Maillet, J. B.; Bourasseau, E.; Desbiens, N.; Vallverdu, G.; Stoltz, G.

    2011-12-01

    An extension of the model described in a previous work (see Maillet J. B. et al., EPL, 78 (2007) 68001) based on Dissipative Particle Dynamics is presented and applied to a liquid high explosive (HE), with thermodynamic properties mimicking those of liquid nitromethane. Large scale nonequilibrium simulations of reacting liquid HE with model kinetic under sustained shock conditions allow a better understanding of the shock-to-detonation transition in homogeneous explosives. Moreover, the propagation of the reactive wave appears discontinuous since ignition points in the shocked material can be activated by the compressive waves emitted from the onset of chemical reactions.

  19. Plasma-depleted holes, waves, and energized particles from high-altitude explosive plasma perturbation experiments

    NASA Technical Reports Server (NTRS)

    Wescott, E. M.; Stenbaek-Nielsen, H. C.; Hallinan, T.; Deehr, C.; Romick, J.; Olson, J.; Kelley, M. C.; Pfaff, R.; Torbert, R. B.; Newell, P.

    1985-01-01

    The results of high-explosive shaped charge experiments King Crab and Bubble Machines I and II, intended to perturb the ambient plasma and magnetic field, are discussed. The instrumentation was flown above an altitude of 460 km in March 1980 and 1981 and comprised a single-axis dipole electric field detector, a fixed bias cylindrical Langmuir probe, a three-axis attitude magnetometer, and curved plated energetic ion and electron electrostatic analyzer. Among the effects of the explosion which are detailed, emphasis is placed on the creation of an ion-depleted dark hole during the Bubble Machine II experiment; mechanisms explaining the phenomenon are outlined. The auroral intensity ion beams with energies of up to 6.8 keV, observed following the explosion in the field-aligned ion electrostatic analyzer, are suggested to represent an existing ion conic population pitch angle scattered by the released barium into the view of the detector.

  20. High-speed photography of the first hydrogen-bomb explosion

    SciTech Connect

    Brixner, B.

    1992-09-01

    Obtaining detailed photographs of the early stages of the first hydrogen bomb explosion in 1952 posed a number of problems. First, it was necessary to invent a continuous-access camera which could solve the problem that existing million-picture-per-second cameras were blind most of the time. The solution here was to alter an existing camera design so that two modified cameras could be mounted around a single high-speed rotating mirror. A second problem, acquiring the necessary lenses of precisely specified focal lengths, was solved by obtaining a large number of production lenses from war surplus salvage. A third hurdle to be overcome was to test the new camera at an A-bomb explosion. Finally, it was necessary to solve the almost impossible difficulty of building a safe camera shelter close to a megaton explosion. This paper describes the way these problems were solved. Unfortunately the successful pictures that were taken are sill classified.

  1. High-speed photography of the first hydrogen-bomb explosion

    SciTech Connect

    Brixner, B.

    1992-01-01

    Obtaining detailed photographs of the early stages of the first hydrogen bomb explosion in 1952 posed a number of problems. First, it was necessary to invent a continuous-access camera which could solve the problem that existing million-picture-per-second cameras were blind most of the time. The solution here was to alter an existing camera design so that two modified cameras could be mounted around a single high-speed rotating mirror. A second problem, acquiring the necessary lenses of precisely specified focal lengths, was solved by obtaining a large number of production lenses from war surplus salvage. A third hurdle to be overcome was to test the new camera at an A-bomb explosion. Finally, it was necessary to solve the almost impossible difficulty of building a safe camera shelter close to a megaton explosion. This paper describes the way these problems were solved. Unfortunately the successful pictures that were taken are sill classified.

  2. Simulating the Thermal Response of High Explosives on Time Scales of Days to Microseconds

    SciTech Connect

    Yoh, J J; McClelland, M A

    2003-07-16

    We present an overview of computational techniques for simulating the thermal cookoff of high explosives using a multi-physics hydrodynamics code, ALE3D. Recent improvements to the code have aided our computational capability in modeling the response of energetic materials systems exposed to extreme thermal environments, such as fires. We consider an idealized model process for a confined explosive involving the transition from slow heating to rapid deflagration in which the time scale changes from days to hundreds of microseconds. The heating stage involves thermal expansion and decomposition according to an Arrhenius kinetics model while a pressure-dependent burn model is employed during the explosive phase. We describe and demonstrate the numerical strategies employed to make the transition from slow to fast dynamics.

  3. An Improved Reaction Rate Equation for Simulating the Ignition and Growth of Reaction in High Explosives

    SciTech Connect

    Murphy, M J

    2010-03-08

    We describe an improved reaction rate equation for simulating ignition and growth of reaction in high explosives. It has been implemented into CALE and ALE3D as an alternate to the baseline the Lee-Tarver reactive flow model. The reactive flow model treats the explosive in two phases (unreacted/reactants and reacted/products) with a reaction rate equation to determine the fraction reacted, F. The improved rate equation has fewer parameters, is continuous with continuous derivative, results in a unique set of reaction rate parameters for each explosive while providing the same functionality as the baseline rate equation. The improved rate equation uses a cosine function in the ignition term and a sine function in the growth and completion terms. The improved rate equation is simpler with fewer parameters.

  4. Simple ideal gas model of the Pavlovskii high-explosive opening switch

    NASA Astrophysics Data System (ADS)

    Tucker, T. J.

    1983-08-01

    The behavior of the Pavlovskii type high-explosive opening switch is modeled using an ideal gas formulation. It is shown that this simple 1 dimensional model agrees with experiment during early arc compression but that at later times the process exhibits a more complex behavior, resulting from turbulent mixing.

  5. A Constitutive Model for Long Time Duration Mechanical Behavior in Insensitive High Explosives

    SciTech Connect

    Darnell, I M; Oh, S; Hrousis, C A; Cunningham, B J; Gagliardi, F J

    2010-03-09

    An anisotropic constitutive model for the long term dimensional stability of insensitive high explosives is proposed. Elastic, creep, thermal, and ratchet growth strains are developed. Pressure and temperature effects are considered. The constitutive model is implemented in an implicit finite element code and compared to a variety of experimental data.

  6. High explosive safety manual. Fifth quarterly technical progress report, October-December 1979

    SciTech Connect

    Albaugh, L.R.; McBride, D.A.

    1980-01-01

    This is the fifth quarterly technical report on a program to prepare a high explosive safety manual for the Department of Energy. The program is described and progress to date is presented. During this work period, the first draft of the manual was completed and the quantitative risk analysis begun.

  7. Trace detection of explosives using an in-line high-volume sampler, preconcentrator, and Fido explosives detector

    NASA Astrophysics Data System (ADS)

    Ingram, Russ; Sikes, John

    2010-04-01

    This paper shall demonstrate the results of a prototype system to detect explosive objects and obscured contaminated targets. By combining a high volume sampling nozzle with an inline 2-stage preconcentrator and a Fido, greater standoff is achieved than with the Fido alone. The direct application of this system is on the Autonomous Mine Detection System (AMDS) but could be deployed on a large variety of robotic platforms. It is being developed under the auspices of the U.S. Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate, Countermine Division. This device is one of several detection tools and technologies to be used on the AMDS. These systems will have multiple, and at times, overlapping objectives. One objective is trace detection on the surface of an unknown potential target. By increasing the standoff capabilities of the detector, the fine manipulation of the robot deploying the detector is less critical. Current detectors used on robotic systems must either be directly in the vapor plume or make direct contact with the target. By increasing the standoff, detection is more easily and quickly achieved. The end result detector must overcome cross-contamination, sample throughput, and environmental issues. The paper will provide preliminary results of the prototype system to include data, and where feasible, video of testing results.

  8. High-speed imaging, acoustic features, and aeroacoustic computations of jet noise from Strombolian (and Vulcanian) explosions

    NASA Astrophysics Data System (ADS)

    Taddeucci, J.; Sesterhenn, J.; Scarlato, P.; Stampka, K.; Del Bello, E.; Pena Fernandez, J. J.; Gaudin, D.

    2014-05-01

    High-speed imaging of explosive eruptions at Stromboli (Italy), Fuego (Guatemala), and Yasur (Vanuatu) volcanoes allowed visualization of pressure waves from seconds-long explosions. From the explosion jets, waves radiate with variable geometry, timing, and apparent direction and velocity. Both the explosion jets and their wave fields are replicated well by numerical simulations of supersonic jets impulsively released from a pressurized vessel. The scaled acoustic signal from one explosion at Stromboli displays a frequency pattern with an excellent match to those from the simulated jets. We conclude that both the observed waves and the audible sound from the explosions are jet noise, i.e., the typical acoustic field radiating from high-velocity jets. Volcanic jet noise was previously quantified only in the infrasonic emissions from large, sub-Plinian to Plinian eruptions. Our combined approach allows us to define the spatial and temporal evolution of audible jet noise from supersonic jets in small-scale volcanic eruptions.

  9. A rapid method for the identification of nitrocellulose in high explosives and smokeless powders using GC-EI-MS.

    PubMed

    Chajistamatiou, Aikaterini S; Bakeas, Evangelos B

    2016-05-01

    Nitrocellulose (NC) is one of the most common ingredients in explosive mixtures, however because of its non-volatility, its detection using Gas Chromatography-Electron Ionization-Mass Spectrometry (GC-EI-MS) has not been achieved until today. A rapid method for the identification of NC in bulk explosives using GC-EI-MS was developed. The sample preparation is simple and takes place in a test tube, employing standard equipment of a forensics laboratory. The protocol was optimized and applied to seven, both high and low, commercial explosives, which contained the substance of interest. Moreover, three explosives in the absence of NC were tested to cross check for false positives. Fourteen different standard explosive substances that are usually found in explosive mixtures were then employed in order to monitor the effect of the method on these compounds and check for interferences. Results showed that NC was detected, by its trimethylsilyl (TMS) derivatives, in all the explosive mixtures analyzed and no false positives were observed. The proposed method showed selectivity for NC, as it had no interference coming from other ingredients of explosive mixtures. The protocol introduced offers considerable improvement in identifying the individual components of an explosive mixture and contributes in successful classification of explosives. PMID:26946027

  10. Modeling of explosive electron emission and electron beam dynamics in high-current devices

    NASA Astrophysics Data System (ADS)

    Anishchenko, S. V.; Gurinovich, A. A.

    2014-03-01

    Based on a detailed analysis of explosive electron emission in high-current electronic devices, we formulate a system of equations that describes the expansion of the cathode plasma and the generation of high-current electron beams. The system underlies the numerical algorithm for the hybrid code which enables simulating the charged particles' dynamics in high-current vircators with open resonators. Using the Gabor-Morlet transform, we perform the time-frequency analysis of vircator radiation.

  11. Calculating the dynamics of High Explosive Violent Response (HEVR) after ignition

    SciTech Connect

    Reaugh, J E

    2008-10-15

    We are developing models to describe the circumstances when molecular and composite explosives undergo a rapid release of energy without detonating, and to describe the evolution of the energy release. The models also apply to the behavior of rocket propellants subject to mechanical insult, whether for accidents (Hazards) or the suite of standardized tests used to assess whether the system can be designated an Insensitive Munition (IM). In the applications described here, we are studying a UK-developed HMX (1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane) explosive, which is 91% by weight HMX and 9% binder-plasticizer. Most explosives and propellants, when subjected to a mechanical insult such as a drop or impact that is well below the threshold for detonation, have been observed to react. In some circumstances the reaction can be violent. This behavior is known as High Explosive Violent Response (HEVR). Fundamental to our model is the observation that the mechanical insult produces damage in a volume of the explosive near the trajectory of the impactor. The damage is manifest as surface area through the creation of cracks and fragments, and also as porosity through the separation of crack faces and isolation of the fragments. Open porosity permits a flame to spread easily and so ignite the newly formed surface area. The additional surface area leads to a direct increase in the mass-burning rate. As the kinetic energy and power of the insult increases, the degree of damage and the volume of damage both increase. Upon a localized ignition, the flame spreads to envelop the damaged volume, and the pressure rises at an accelerated rate until neither mechanical strength nor inertial confinement can successfully contain the pressure. The confining structure begins to expand. This reduces the pressure and may even extinguish the flame. Both the mass of explosive involved and the rate at which the gas is produced contribute to each of several different measures of violence

  12. Hydrogen Explosion Analysis for Cold Source Installation at the High Flux Isotope Reactor

    SciTech Connect

    Cook, David Howard

    2008-01-01

    Installation of a cold neutron source in the High Flux Isotope Reactor (HFIR) involved introduction of pressurized, cryogenic hydrogen into the facility and created explosion hazards to reactor safety-related equipment and personnel. Evaluation of potential hydrogen releases and facility/personnel consequences as a result of explosions was a key part of the safety analyses submitted to the DOE to obtain approval for testing and operation with hydrogen. This paper involves a description of the various hydrogen release and explosion consequence analyses that were performed. The range of explosion calculations involved (1) a detonation analysis using a 2D-transient CTH code model, (2) various BLAST/FX code models to estimate structural damage from equivalent point TNT sources, (3) a BLASTX code model to propagate shock and gas flow overpressures from a point TNT source, (4) a spreadsheet that combined a TNT-quivalence model and strong deflagration methods, and (5) a hydrogen jet model to evaluate potential high pressure jet releases.

  13. On the quantitative measurement of fracture toughness in high explosive and mock materials

    SciTech Connect

    Liu, Cheng; Cady, Carl M; Rae, Philip J; Lovato, Manuel L

    2010-01-01

    Two approaches in measuring the fracture toughness of heterogeneous high explosives and their mocks are explored in this investigation. One is the global measurement according to the ASTM E 1820-06 standard, which is primarily developed for metallic materials to obtain quantitative measurement of parameters such as the stress intensity factor, the J-integral, and the crack-tip opening displacement (CTOD). The second approach is based on local measurements using digital image correlation (DIC). Detailed results and comparisons of the two strategies will be presented for the Mock 900-21, a mechanical simulant of the PBX 9501 high explosive. Cracking is the most dominant mechanical failure mechanism in high explosives (HE) and a key parameter for describing and predicting crack initiation and extension is the fracture toughness. Quantitative measurement of such material property poses challenges, and this is mainly because that the material is highly heterogeneous with a very complicated microstructure and the contrast of the mechanical properties of the constituents is also remarkably high. In this investigation, we explore two strategies in measuring the fracture toughness of heterogeneous high explosives and their mocks. The first approach is based on the global measurement according to the ASTM E 1820-06 standard, which is primarily developed for metallic materials to obtain quantitative measurement of parameters such as the stress intensity factor, the J-integral, and the crack-tip opening displacement (CTOD). However, there are difficulties in applying the ASTM standard on energetic solids that include identifying the moment of crack initiation and pinpointing exact crack length at each instant of time. The second approach is based on local measurements. We developed a technique for quantitatively identifying the location and extent of macroscopic cracks in heterogeneous high explosive and mock material. By combining such a technique with the displacement field

  14. Response of standard and high-capacity HEPA filters to simulated tornado and explosive transients

    SciTech Connect

    Gregory, W.S.; Smith, P.R.

    1982-03-01

    An investigation was performed to determine the response of standard and high-capacity high-efficiency particulate air filters to simulated tornado and explosive transients. Most of the tests were directed toward evaluating the structural response of high-capacity filters to explosive transients. Selected tests were performed to evaluate the effects of particulate loading on filtration efficiencies. Also, several of the high-capacity filters were subjected to simulated toronado transients. The results indicate that the upper structural limits of high-capacity filters for explosive loading is 6.89-kPa (1-psi) peak pressure and 100-kPa-ms (14.51-psi-ms) impulse. These limits are below the approximately 13.78-kPa (2-psi) peak pressure loadings found for standard HEPA filters. Tests of high-capacity filters preloaded with aerosol indicated that the structural limits were further degraded by approximately 40%. The filtration efficiencies were degraded to approximately 70% when the filters were subjected to aerosol entrained within the shock pulse. The effect of simulated tornado transients on high-capacity filters resulted in an upper structural limit of 11.02 kPa (1.6 psi) for peak pressure.

  15. On the high fidelity simulation of chemical explosions and their interaction with solid particle clouds

    NASA Astrophysics Data System (ADS)

    Balakrishnan, Kaushik

    The flow field behind chemical explosions in multiphase environments is investigated using a robust, state-of-the-art simulation strategy that accounts for the thermodynamics, gas dynamics and fluid mechanics of relevance to the problem. Focus is laid on the investigation of blast wave propagation, growth of hydrodynamic instabilities behind explosive blasts, the mixing aspects behind explosions, the effects of afterburn and its quantification, and the role played by solid particles in these phenomena. In particular, the confluence and interplay of these different physical phenomena are explored from a fundamental perspective, and applied to the problem of chemical explosions. A solid phase solver suited for the study of high-speed, two-phase flows has been developed and validated. This solver accounts for the inter-phase mass, momentum and energy transfer through empirical laws, and ensures two-way coupling between the two phases, viz. solid particles and gas. For dense flow fields, i.e., when the solid volume fraction becomes non-negligible (˜60%), the finite volume method with a Godunov type shock-capturing scheme requires modifications to account for volume fraction gradients during the computation of cell interface gas fluxes. To this end, the simulation methodology is extended with the formulation of an Eulerian gas, Lagrangian solid approach, thereby ensuring that the so developed two-phase simulation strategy can be applied for both flow conditions, dilute and dense alike. Moreover, under dense loading conditions the solid particles inevitably collide, which is accounted for in the current research effort with the use of an empirical collision/contact model from literature. Furthermore, the post-detonation flow field consists of gases under extreme temperature and pressure conditions, necessitating the use of real gas equations of state in the multiphase model. This overall simulation strategy is then extended to the investigation of chemical explosions in

  16. Low amplitude impact testing and analysis of pristine and aged solid high explosives

    SciTech Connect

    Chidester, S K; Garza, R; Tarver, C M

    1998-08-17

    The critical impact velocities of 60.1 mm diameter blunt steel projectiles required for ignition of exothermic chemical reaction were determined for heavily confined charges of new and aged (15-30 years) solid HMX-based high explosives. The explosives in order of decreasing impact sensitivity were: PBX 9404; LX-lo; LX-14; PBX 9501; and LX-04. Embedded pressure gauges measured the interior pressure histories. Stockpile aged LX-04 and PBX 9501 from dismantled units were tested and compared to freshly pressed charges. The understanding of explosive aging on impact ignition and other hazards must improve as systems are being deployed longer than their initial estimated lifetimes. The charges that did not react on the first impact were subjected to multiple impacts. While the violence of reaction increased with impact velocity, it remained much lower than that produced by an intentional detonation. Ignition and Growth reactive flow models were developed to predict HMX-based explosive impact sensitivity in other geometries and scenarios.

  17. Development, testing and practical use of two special containment vessels for storage and transportation of high explosives

    SciTech Connect

    Dikken, H. den

    1995-12-31

    The storage and transportation of high explosives gives many logistic managers a headache, especially when it comes to forwarding of small quantities. Air transport is limited to 1.4 explosives on cargo aircraft and 1.4S classified explosives on passenger aircraft, so most samples cannot be transported by air. Ocean transport is a possibility, but due to stowage and segregation regulations of the IMDG code, a very expensive one. Road transport is often the only solution, but high explosives require special trucks with licensed drivers. The solution to these logistic problems is solved by creating a 1.4S (Class C) classification for all high explosives, when packed in special containment vessels.

  18. Numerical Modeling of Impact Initiation of High Explosives

    SciTech Connect

    Wu, C J; Piggott, T; Yoh, J; Reaugh, J

    2006-05-31

    We performed continuum mechanics simulations to examine the behavior of energetic materials in Ballistic Chamber Impact (BIC) experiments, using an Arbitrary Lagrangian-Eulerian code (ALE3D). Our simulations revealed that interface friction plays an important role in inducing the formation of shear bands, which result in 'hot spots' for ignition. The temperature localization during BIC impact was found to be significant in materials with high yield strength. In those materials, there are multiple locations inside shear bands can achieve temperatures exceeding the threshold temperature for reaction. In addition, we investigated the relevant parameters influencing the pressure profile of a BIC test by numerical analysis from a simple phenomenological model. To our surprise, we found that the peaks of BIC pressure profiles not only can be a result of multi-center chemical reactions, but can also arise from factors associated apparatus configuration.

  19. High PCB residues in birds from the Sheboygan River, Wisconsin

    USGS Publications Warehouse

    Heinz, G.H.; Swineford, D.M.; Katsma, D.E.

    1984-01-01

    Organochlorine residues were measured in the carcasses and, in some cases, brains and stomach contents of four species of birds collected along the Sheboygan River, Wisconsin during the years 1976 to 1980. Polychlorinated biphenyls (PCBs) were high in all samples and were the contaminants of greatest concern. Carcass residues ranged from 23 to 218 ppm PCBs on a wet weight basis; these are levels associated with reproductive impairment in laboratory studies with some birds. Food items in the stomachs of collected birds contained from 12 to 58 ppm PCBs, indicating a heavy contamination of food sources. The brain of one bird contained 220 ppm PCBs, a level that is not in the lethal range but is very high. Birds feeding in the contaminated portions of the Sheboygan River may have been harmed by high PCB levels.

  20. Modeling thermally driven energetic response of high explosives

    SciTech Connect

    Sharp, R; Couch, R; McCallen, R C; Nichols III, A L; Otero, I

    1998-02-01

    We have improved our ability to model the response of energetic materials to thermal stimuli and the processes involved in the energetic response. Traditionally, the analyses of energetic materials have involved coupled thermal transport/chemical reaction codes. This provides only a reasonable estimate of the time and location of ensuing rapid reaction. To predict the violence of the reaction, the mechanical motion must be included in the wide range of time scales associated with the thermal hazard. The ALE3D code has been modified to assess the hazards associated with heating energetic materials in weapons by coupling to thermal transport model and chemistry models. We have developed an implicit time step option to efficiently and accurately compute the hours of heating to reaction of the energetic material. Since, on these longer time scales materials can be expected to have significant motion, it is even more important to provide high-order advection for all components, including the chemical species. We show two examples of coupled thermal/mechanical/chemical models of energetic materials in thermal environments.

  1. Modeling thermally driven energetic response of high explosives

    SciTech Connect

    Couch, R; McCallen, R C; Nichols III, A L; Otero, I; Sharp, R

    1998-08-17

    We have improved our ability to model the response of energetic materials to thermal stimuli and the processes involved in the energetic response. Traditionally, the analyses of energetic materials have involved coupled thermal transport/chemical reaction codes. This provides only a reasonable estimate of the time and location of ensuing rapid reaction. To predict the violence of the reaction, the mechanical motion must be included in the wide range of time scales associated with the thermal hazard. The ALE3D code has been modified to assess the hazards associated with heating energetic materials in weapons by coupling to thermal transport model and chemistry models. We have developed an implicit time step option to efficiently and accurately compute the hours of heating to reaction of the energetic material. Since, on these longer time scales materials can be expected to have significant motion, it is even more important to provide high-order advection for all components, including the chemical species. We show two examples of coupled thermal/mechanical/chemical models of energetic materials in thermal environments.

  2. On the effect of grain size on shock sensitivity of heterogeneous high explosives

    NASA Astrophysics Data System (ADS)

    Khasainov, B. A.; Ermolaev, B. S.; Presles, H.-N.; Vidal, P.

    Analysis of available data on dependence of the critical detonation diameter dcr of various heterogeneous condensed explosives on mean size of grains and voids demonstrated that in many cases surprising correlations between dcr and the initial specific surface area of heterogeneous explosives Ao exist, namely, dcr=α 1+α 2/A_o or 1/dcr=β 1+β 2A_o. The run distance to detonation in wedge test with sustained strong shock of constant amplitude also linearly correlates with 1/Ao, i.e. L{P= Const}=γ 1+γ 2/A_o. At the same time, the shock sensitivity reversal effect is often observed when grain size of HE is reduced. Apart from that Moulard (1989) found that detonation critical diameter of plastic bonded explosive with mono- and bimodal RDX grain size distribution depends nonmonotonously on mean grain size. Complicated dependence of shock sensitivity of heterogeneous explosives on their specific surface area can be explained based on comparison of the critical hot spot size a*(P) at given characteristic pressure behind shock wave P with the mean heterogeneity size /line{a}. At high characteristic pressure (relative to the critical ignition pressure) a* is small compared with /line{a} and all specific surface area of heterogeneous explosive is available for the hot spot growth process in accordance with the grain burn concept. However, when characteristic pressure of shock wave decreases, a*(P) increases and can become comparable with /line{a}. In this case only relatively large potential hot spots (with size a>a*) can result in self-supported hot spot growth process and shock sensitivity is controlled by the specific surface area which corresponds to only larger heterogeneities and can be significantly smaller than initial specific surface area.

  3. Compact submicrosecond, high current generator for wire explosion experiments

    NASA Astrophysics Data System (ADS)

    Aranchuk, L. E.; Chuvatin, A. S.; Larour, J.

    2004-01-01

    The PIAF generator was designed for low total energy and high energy density experiments with liners, X-pinch or fiber Z-pinch loads. These studies are of interest for such applications as surface and material science, microscopy of biological specimens, lithography of x-ray sensitive resists, and x-ray backlighting of pulsed-power plasmas. The generator is based on an RLC circuit that includes six NWL 180 nF-50 kV capacitors that store up to 1.3 kJ. The capacitors are connected in parallel to a single multispark switch designed to operate at atmospheric pressure. The switch allows reaching a time delay between the trigger pulse and the current pulse of less than 80 ns and has jitter of 6 ns. The total inductance without a load compartment was optimized to be as low as 16 nH, which leads to extremely low impedance of ˜0.12 Ω. A 40 kV initial voltage provides 250 kA maximum current in a 6 nH inductive load with a 180 ns current rise time. PIAF has dimensions of 660×660×490 mm and weight of less than 100 kg, thus manifesting itself as robust, simple to operate, and cost effective. A description of the PIAF generator and the initial experimental results on PIAF with an X-pinch type load are reported. The generator was demonstrated to operate successfully with an X-pinch type load. The experiments first started with investigation of the previously unexplored X-pinch conduction time range, 100 ns-1 μs. A single short radiation pulse was obtained that came from a small, point-like plasma. The following x-ray source characteristics were achieved: typical hot spot size of 50-100 μm, radiation pulse duration of 1.5-2 ns, and radiation yield of about 250-500 mJ in the softer spectral range (hν⩾700 eV) and 50-100 mJ in the harder one (hν⩾1 keV). These results provide the potential for further application of this source, such as use as a backlight diagnostic tool.

  4. Modelling Of Residual Stresses Induced By High Speed Milling Process

    NASA Astrophysics Data System (ADS)

    Desmaison, Olivier; Mocellin, Katia; Jardin, Nicolas

    2011-05-01

    Maintenance processes used in heavy industries often include high speed milling operations. The reliability of the post-process material state has to be studied. Numerical simulation appears to be a very interesting way to supply an efficient residual stresses (RS) distribution prediction. Because the adiabatic shear band and the serrated chip shaping are features of the austenitic stainless steel high speed machining, a 2D high speed orthogonal cutting model is briefly presented. This finite element model, developed on Forge® software, is based on data taken from Outeiro & al.'s paper [1]. A new behaviour law fully coupling Johnson-Cook's constitutive law and Latham and Cockcroft's damage model is detailed in this paper. It ensures results that fit those found in literature. Then, the numerical tools used on the 2D model are integrated to a 3D high speed milling model. Residual stresses distribution is analysed, on the surface and into the depth of the material. Various revolutions and passes of the two teeth hemispheric mill on the workpiece are simulated. Thus the sensitivity of the residual stresses generation to the cutting conditions can be discussed. In order to validate the 3D model, a comparison of the cutting forces measured by EDF R&D to those given by numerical simulations is achieved.

  5. Modelling Of Residual Stresses Induced By High Speed Milling Process

    SciTech Connect

    Desmaison, Olivier; Mocellin, Katia; Jardin, Nicolas

    2011-05-04

    Maintenance processes used in heavy industries often include high speed milling operations. The reliability of the post-process material state has to be studied. Numerical simulation appears to be a very interesting way to supply an efficient residual stresses (RS) distribution prediction.Because the adiabatic shear band and the serrated chip shaping are features of the austenitic stainless steel high speed machining, a 2D high speed orthogonal cutting model is briefly presented. This finite element model, developed on Forge registered software, is based on data taken from Outeiro and al.'s paper [1]. A new behaviour law fully coupling Johnson-Cook's constitutive law and Latham and Cockcroft's damage model is detailed in this paper. It ensures results that fit those found in literature.Then, the numerical tools used on the 2D model are integrated to a 3D high speed milling model. Residual stresses distribution is analysed, on the surface and into the depth of the material. Various revolutions and passes of the two teeth hemispheric mill on the workpiece are simulated. Thus the sensitivity of the residual stresses generation to the cutting conditions can be discussed. In order to validate the 3D model, a comparison of the cutting forces measured by EDF R and D to those given by numerical simulations is achieved.

  6. Progress in model development to quantify High Explosive Violent Response (HEVR) to mechancial insult

    SciTech Connect

    Reaugh, J E

    2008-07-29

    The rapid release of chemical energy has found application for industrial and military purposes since the invention of gunpowder. Black powder, smokeless powder of various compositions, and pyrotechnics all exhibit the rapid release of energy without detonation when they are being used as designed. The rapidity of energy release for these materials is controlled by adjustments to the particle surface area (propellant grain configuration or powder particle size) in conjunction with the measured pressure-dependent burning rate, which is very subsonic. In this way a manufacturing process can be used to engineer the desired violence of the explosion. Detonations in molecular explosives, in contrast, propagate with a supersonic velocity that depends on the loading density, but is independent of the surface area. In ideal detonations, the reaction is complete within a small distance of the propagating shock front. Non-ideal detonations in molecular and composite explosives proceed with a slower velocity, and the reaction may continue well behind the shock front. We are developing models to describe the circumstances when molecular and composite explosives undergo a rapid release of energy without detonating. The models also apply to the behavior of rocket propellants subject to mechanical insult, whether for accidents (Hazards) or the suite of standardized tests used to assess whether the system can be designated an Insensitive Munition (IM). In the application described here, we are studying an HMX (1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane) explosive developed in the UK, which is 91% by weight HMX and 9% binder-plasticizer. Most explosives and propellants, when subjected to a mechanical insult, drop or impact that is well below the threshold for detonation have been observed to react violently. This behavior is known as High Explosive Violent Reaction (HEVR). The basis of our model is the observation that the mechanical insult produces damage in a volume of the

  7. Single and multiple impact ignition of new and aged high explosives in the Steven Impact Test

    SciTech Connect

    Chidester, S K; DePiero, A H; Garza, R G; Tarver, C M

    1999-06-01

    Threshold impact velocities for ignition of exothermic reaction were determined for several new and aged HMX-based solid high explosives using three types of projectiles in the Steven Test. Multiple impact threshold velocities were found to be approximately 10% lower in damaged charges that did not react in one or more prior impacts. Projectiles with protrusions that concentrate the friction work in a small volume of explosive reduced the threshold velocities by approximately 30%. Flat projectiles required nearly twice as high velocities for ignition as rounded projectiles. Blast overpressure gauges were used for both pristine and damaged charges to quantitatively measure reaction violence. Reactive flow calculations of single and multiple impacts with various projectiles suggest that the ignition rates double in damaged charges.

  8. Ground motion analyses: OSSY (a high explosive experiment) and MERLIN (a nuclear event)

    SciTech Connect

    Swift, R.P.

    1991-10-01

    We have analyzed recorded data and conducted numerical simulations of the seismic-calibration high explosive experiment OSSY and of the underground nuclear event MERLIN to determine if there is any physical correlation in their ground motion response. Waveforms recorded on OSSY and MERLIN show a distinct similarity in the form of a dual-pulse structure, with the second pulse as large or larger than the first pulse. Results with 1D and 2D simulations show that there is no correlation. The dual-pulse structure for OSSY can best be accounted for by a dilatancy feature resulting from pore recovery during unloading. There is also a notable influence on the pulse shape caused by the large length-to-diameter ratio of the high explosive charge. The dual-pulse structure recorded in MERLIN is most likely due to refraction from a higher-impedance layer about 60 m below the workout. 15 refs., 26 figs.

  9. Implementation of a High Explosive Equation of State into an Eulerian Hydrocode

    NASA Astrophysics Data System (ADS)

    Littlefield, David L.; Baker, Ernest L.

    2004-07-01

    The implementation of a high explosive equation of state into the Eulerian hydrocode CTH is described. The equation of state is an extension to JWL referred to as JWLB, and is intended to model the thermodynamic state of detonation products from a high explosive reaction. The EOS was originally cast in a form p = p(ρ, e), where p is the pressure, ρ is the density and e is the internal energy. However, the target application code requires an EOS of the form p = p(ρ, T), where T is the temperature, so it was necessary to reformulate the EOS in a thermodynamically consistent manner. A Helmholtz potential, developed from the original EOS, insures this consistency. Example calculations are shown that illustrate the veracity of this implementation.

  10. Generation of Electric and Magnetic Fields During Detonation of High Explosive Charges in Boreholes

    SciTech Connect

    Soloviev, S; Sweeney, J

    2004-06-04

    We present experimental results of a study of electromagnetic field generation during underground detonation of high explosive charges in holes bored in sandy loam and granite. Test conditions and physico-mechanical properties of the soil exert significant influence on the parameters of electromagnetic signals generated by underground TNT charges with masses of 2 - 200 kg. The electric and magnetic field experimental data are satisfactorily described by an electric dipole model with the source embedded in a layered media.

  11. High-throughput baggage scanning employing x-ray diffraction for accurate explosives detection

    NASA Astrophysics Data System (ADS)

    Green, Michael C.; Partain, Larry D.

    2003-07-01

    X-ray systems dominate the installed base of airport baggage scanning systems for explosives detection. The majority are conveyer systems with projection line scanners. These systems can achieve a high throughput but exhibit a high false positive rate and require significant operator involvement. Systems employing computed tomography (CT) are currently being installed at a rapid rate. These can provide good discrimination of levels of xray absorption coefficient and can largely circumvent superimposition effects. Nonetheless CT measures only x-ray absorption coefficient per voxel which does not provide a means of specific material identification resulting in many false positives, and it is relatively straightforward to configure explosive materials so that they are undetectable by CT systems. Diffraction-based x-ray systems present a solution to this problem. They detect and measure atomic layer spacings in crystalline and microcrystalline materials with high sensitivity. This provides a means of specific material identification. The majority of explosive compounds are well crystallized solids at room temperature. X-ray diffraction systems using both conventional wavelength-dispersive diffraction and fixed-angle, multi-wavelength diffraction for improved throughput are described. Large-area, flat-panel x-ray detector technology coupled with an extended x-ray source will permit a full 3D volumetric x-ray diffraction scan of a bag in a single pass, (patent pending).

  12. Rapid pyrolysis of agricultural residues at high temperatures

    SciTech Connect

    Zanzi, R.; Sjoestroem, K.; Bjoernbom, E.

    1995-11-01

    Agriculture plays an important role in the economy of many countries especially in Latin America. Gasification of agricultural residues such as bagasse from sugar cane for electricity production is a solution to meet energy demands with a favourable effect on the environment. Pyrolysis (heating solid biomass in absence of air to produce solid, liquid or gaseous fuels) is the first step in gasification and combustion. Depending on the conditions the solid, liquid or gaseous products are maximized. The treatment conditions in the pyrolysis determine the char yield and its reactivity in gasification. Char yield and char reactivity are important for the capacity of the gasifier. The rapid pyrolysis of biomass is performed in a free-fall reactor at 850{degrees}C. The biomass used in the study was wood (birch) and agricultural residues such as bagasse and leaves both from sugar cane and banana. The reactivity of the char obtained in pyrolysis is determined by reaction with steam in a thermobalance. The low amounts of a highly porous char and the high yield of gaseous products obtained in rapid pyrolysis of bagasse at high temperature are similar to those produced in rapid pyrolysis of wood. Bagasse gives more volatiles and less char than sugar cane residues and banana harvest residues. Bagasse produces a less reactive char after devolatilization than wood. The char obtained by rapid pyrolysis contains a fraction that can be further volatilized by slow pyrolysis. The fraction of char removed by slow pyrolysis is lower in chars from bagasse and sugar cane leaves than in chars from wood. The structures of the chars obtained from birch, bagasse, sugar cane and banana leaves were observed by scanning electron microscope. Qualitative X-ray microanalysis of the chars was made using an electron microscope supplied with an energy dispersive spectrometer. Ca, K, S, Si, Al and Mg were visible on the surface of the chars.

  13. Avian community composition in response to high explosive testing operations at Los Alamos National Laboratory in Northern New Mexico

    DOE PAGESBeta

    Keller, David C.; Fresquez, Philip R.; Hansen, Leslie A.; Kaschube, Danielle R.

    2015-12-28

    Breeding bird abundance, species richness, evenness, diversity, composition, productivity, and survivorship were determined near a high-explosive detonation site at Los Alamos National Laboratory, New Mexico, USA, during pre-operation (1997-1999) and operation (2000-2014) periods. The operation periods consisted of detonations (<23 kg in yield and <3 per breeding season) in open air (2000-2002), within foam containment (2003-2006) and within steel vessel containment (2007-2014) systems; the latter two were employed to reduce noise and dispersal of high-explosives residues. A total of 2952 bird captures, representing 80 species, was recorded during 18 years of mist net operations using the Monitoring Avian Productivity andmore » Survivorship protocol. Individuals captured were identified to species, aged, sexed, and banded during May through August of each year. There were no significant differences (p > 0.05) in mean avian abundance and species evenness in any of the operation periods as compared with the pre-operation period. Species richness and diversity were significantly higher (p < 0.05) during the vessel containment period (2007-2014) than the pre-operation period. The time period of this study coincided with a wildfire (2000), a bark beetle infestation (2002), and two periods of drought (Nov 1999-Mar 2004 and Dec 2005-Dec 2014) that affected the study area. Furthermore, analysis of aerial photos determined that the average percent canopy cover of mature ponderosa pines (Pinus ponderosa) within 100 feet of mist net sites declined from 12% to 3% between 1991 and 2014 and the percent cover of shrubs slightly increased.« less

  14. Avian community composition in response to high explosive testing operations at Los Alamos National Laboratory in Northern New Mexico

    SciTech Connect

    Keller, David C.; Fresquez, Philip R.; Hansen, Leslie A.; Kaschube, Danielle R.

    2015-12-28

    Breeding bird abundance, species richness, evenness, diversity, composition, productivity, and survivorship were determined near a high-explosive detonation site at Los Alamos National Laboratory, New Mexico, USA, during pre-operation (1997-1999) and operation (2000-2014) periods. The operation periods consisted of detonations (<23 kg in yield and <3 per breeding season) in open air (2000-2002), within foam containment (2003-2006) and within steel vessel containment (2007-2014) systems; the latter two were employed to reduce noise and dispersal of high-explosives residues. A total of 2952 bird captures, representing 80 species, was recorded during 18 years of mist net operations using the Monitoring Avian Productivity and Survivorship protocol. Individuals captured were identified to species, aged, sexed, and banded during May through August of each year. There were no significant differences (p > 0.05) in mean avian abundance and species evenness in any of the operation periods as compared with the pre-operation period. Species richness and diversity were significantly higher (p < 0.05) during the vessel containment period (2007-2014) than the pre-operation period. The time period of this study coincided with a wildfire (2000), a bark beetle infestation (2002), and two periods of drought (Nov 1999-Mar 2004 and Dec 2005-Dec 2014) that affected the study area. Furthermore, analysis of aerial photos determined that the average percent canopy cover of mature ponderosa pines (Pinus ponderosa) within 100 feet of mist net sites declined from 12% to 3% between 1991 and 2014 and the percent cover of shrubs slightly increased.

  15. Identification of Explosives from Porous Materials: Applications Using Reverse Phase High Performance Liquid Chromatography and Gas Chromatography

    SciTech Connect

    C.J. Miller; G. Elias; N.C. Schmitt; C. Rae

    2010-06-01

    High performance liquid chromatography and gas chromatography techniques are well documented and widely used for the detection of trace explosives from organic solvents. These techniques were modified to specifically identify and quantify explosives extracted from various materials taken from people who had recently handled explosives. Documented techniques were modified to specifically detect and quantify RDX, TNT, and PETN from denim, colored flannel, vinyl, and canvas extracted in methanol using no sample cleanup prior to analysis. The methanol extracts were injected directly into several different column types and analyzed by HPLC-UV and/or GC-ECD. This paper describes general screening methods that were used to determine the presence of explosives in unknown samples and techniques that have been optimized for quantification of each explosive from the substrate extracts.

  16. Effect of slow energy releasing on divergent detonation of Insensitive High Explosives

    NASA Astrophysics Data System (ADS)

    Hu, Xiaomian; Pan, Hao; Huang, Yong; Wu, Zihui

    2014-03-01

    There exists a slow energy releasing (SER) process in the slow reaction zone located behind the detonation wave due to the carbon cluster in the detonation products of Insensitive High Explosives (IHEs), and the process will affect the divergent detonation wave's propagation and the driving process of the explosives. To study the potential effect, a new artificial burn model including the SER process based on the programmed burn model is proposed in the paper. Quasi-steady analysis of the new model indicates that the nonlinearity of the detonation speed as a function of front curvature owes to the significant change of the reaction rate and the reaction zone length at the sonic state. What's more, in simulating the detonation of IHE JB-9014, the new model including the slow reaction can predict a slower jump-off velocity, in good agreement with the result of the test.

  17. Mechanisms of formation of trace decomposition products in complex high explosive mixtures

    SciTech Connect

    Woodyard, J.D.; Burgess, C.E.; Rainwater, K.A.

    1999-03-01

    A significant concern in the nation`s stockpile surveillance program in prediction of the lifetimes of the high explosives (HE) and their components as the weapons age. The Department of Energy`s Core Surveillance and Enhanced Surveillance programs specifically target issues of degradation of HE, binders, and plastic-bonded explosives (PBX) for determination of component lifetimes and handling procedures. These material science topics are being addressed at the DOE national laboratories and production plants, including Pantex. The principal goal of this project is to identify the mechanisms of decomposition of HE, plasticizers, plastic polymer binders, and radical stabilizers resulting from exposures to ionizing radiation, heat, and humidity. The following reports the work completed for 1998, including a comprehensive literature review about some of the materials examined and the laboratory work completed to date. The materials focused on in the laboratory are TATB, Estane 5301, and Irganox 1010.

  18. Engineering support for LLNL Chemistry's High Explosive Technology group. Final report

    SciTech Connect

    Weston, A.M.; James, E.

    1985-12-01

    Support for the Lawrence Livermore National Laboratory (LLNL) High Explosive Technology (HET), part of the Chemistry Division is described. Brief progress reports are presented for the following six tasks: (1) assess mechanical and explosive response of proposed extreme environmental weapon systems; (2) perform a hazard study relating to Trident D-5 motor response; (3) continue development and application of the deflagration to detonation (DDT) computer model (code RDUCT) for the hazard assessment for rocket propellants (HARP) program; (4) perform rocket motor vulnerability calculations for a proposed new air force mobile missile; (5) perform additional analyses relating to radioisotope thermo-electric generator PuO2 containment with possible NASA space shuttle accident scenarios; and (6) develop a relational data base for information pertinent to the hazard studies relating to the Trident D-5 motor response and the associated HARP program. (AT)

  19. Transmission and Reflection Terahertz Spectroscopy of Insensitive Melt-Cast High-Explosive Materials

    NASA Astrophysics Data System (ADS)

    Palka, Norbert; Szala, Mateusz

    2016-05-01

    Currently, artillery shells and grenades that are introduced into the market are based on melt-castable insensitive high explosives (IHEs), which do not explode while they run a risk of impact, heat or shrapnel. Particles of explosives (such as hexogen, nitroguanidine and nitrotriazolone) are suspended in different proportions in a matrix of 2.4-dinitroanisole. In this paper, we investigated samples of commonly used IHEs: PAX-41, IMX-104 and IMX-101, whose internal structures were determined by a scanning electron microscope. Terahertz time domain spectroscopy was applied in both transmission and reflection configurations. At first, the complex refraction indices of four pure constituents creating IHEs were determined and became the basis of further calculations. Next, the experimentally determined transmission and reflection spectra of IHEs and pure constituents were compared with theoretical considerations. The influence of the grain size of constituent material and scattering on the reflection spectra was analysed, and good agreement between the experimental and theoretical data was achieved.

  20. Hydrodynamic Modeling of Air Blast Propagation from the Humble Redwood Chemical High Explosive Detonations Using GEODYN

    SciTech Connect

    Chipman, V D

    2011-09-20

    Two-dimensional axisymmetric hydrodynamic models were developed using GEODYN to simulate the propagation of air blasts resulting from a series of high explosive detonations conducted at Kirtland Air Force Base in August and September of 2007. Dubbed Humble Redwood I (HR-1), these near-surface chemical high explosive detonations consisted of seven shots of varying height or depth of burst. Each shot was simulated numerically using GEODYN. An adaptive mesh refinement scheme based on air pressure gradients was employed such that the mesh refinement tracked the advancing shock front where sharp discontinuities existed in the state variables, but allowed the mesh to sufficiently relax behind the shock front for runtime efficiency. Comparisons of overpressure, sound speed, and positive phase impulse from the GEODYN simulations were made to the recorded data taken from each HR-1 shot. Where the detonations occurred above ground or were shallowly buried (no deeper than 1 m), the GEODYN model was able to simulate the sound speeds, peak overpressures, and positive phase impulses to within approximately 1%, 23%, and 6%, respectively, of the actual recorded data, supporting the use of numerical simulation of the air blast as a forensic tool in determining the yield of an otherwise unknown explosion.

  1. Individual contributions of friction and impact on non-shock initiation of high explosives

    NASA Astrophysics Data System (ADS)

    Peterson, Paul; Avilucea, Gabe; Bishop, Robert; Sanchez, John

    2007-06-01

    Throughout the years a variety of tests have been designed which provide insight into the sensitivity of high explosives (HE) to non-shock initiation. Various standard tests such as the LANL drop weight impact, LLNL drop hammer, drop tower and skid tests have been developed to measure energetic response of explosives subjected to a combination of friction and oblique impact. In addition, the BAM test (for HE powders on roughened ceramic) and ABL friction test (powders or solids on roughened metal) have been developed for testing HE under frictional loading. In an effort to understand first principles of non-shock initiation, we have designed a series of tests to try to isolate friction and impact during the insult of HE. An initial series of tests have been completed with PETN, HMX, and as-pressed pellets of PBX 9501 (95 wt. percent HMX, 5 wt. percent inert binder), PBX 9502 (95 wt. percent TATB, wt. percent inert binder), Cyclotol (75 wt. percent RDX/25, wt. percent TNT), and Comp B3 (60 wt. percent RDX, 40 wt. percent TNT). The results suggest that some types of high explosives are relatively insensitive to pure impact and pure friction but relatively sensitive to insults involving a combination of impact and friction.

  2. Individual Contributions of Friction and Impact on Non-Shock Initiation of High Explosives

    NASA Astrophysics Data System (ADS)

    Peterson, P. D.; Avilucea, G. R.; Bishop, R. L.; Sanchez, J. A.

    2007-12-01

    Throughout the years a variety of tests have been designed which provide insight into the sensitivity of high explosives (HE) to non-shock initiation. Various standard tests such as the LANL drop weight impact, LLNL drop hammer, drop tower and skid tests have been developed to measure energetic response of explosives subjected to a combination of friction and oblique impact. In addition, the BAM test (for HE powders on roughened ceramic) and ABL friction test (powders or solids on roughened metal) have been developed for testing HE under frictional loading. In an effort to understand first principles of non-shock initiation, we have designed a series of tests to try to isolate friction and impact during the insult of HE. An initial series of tests have been completed with PETN, HMX, and as-pressed pellets of PBX 9501 (95 wt% HMX, wt% inert binder), PBX 9502 (95 wt% TATB, 5 wt% inert binder), Cyclotol (75 wt% RDX/25, wt% TNT), and Comp B3 (60 wt% RDX, 40 wt% TNT). The results suggest that some types of high explosives are relatively insensitive to pure impact and pure friction but relatively sensitive to insults involving a combination of impact and friction.

  3. Micro- and nano- second time scale, high power electrical wire explosions in water.

    NASA Astrophysics Data System (ADS)

    Grinenko, Alon; Efimov, Sergey; Sayapin, Arkadii; Fedotov, Alexander; Gurovich, Viktor; Krasik, Yakov

    2006-10-01

    Experimental and magneto-hydro-dynamic simulation results of micro- and nanosecond time scale underwater electrical Al, Cu and W wires explosions are presented. A capacitor bank with stored energy up to 6 kJ (discharge current up to 80 kA with 2.5 μs quarter period) was used in microsecond time scale experiments and water forming line generator with current amplitude up to 100 kA and pulse duration of 100 ns were used in nanosecond time scale experiments. Extremely high energy deposition of up to 60 times the atomization enthalpy was registered in nanosecond time scale explosions. A discharge channel evolution and surface temperature were analyzed by streak shadow imaging and using fast photo-diode with a set of interference filters, respectively. Microsecond time scale electrical explosion of cylindrical wire array showed extremely high pressure of converging shock waves at the axis, up to 0.2 MBar. A 1D and 2D magneto-hydro-dynamic simulation demonstrated good agreement with such experimental parameters as discharge channel current, voltage, radius, and temperature.

  4. VISAR Validation Test Series at the Light Initiated High Explosive (LIHE) facility.

    SciTech Connect

    Covert, Timothy Todd

    2007-02-01

    A velocity interferometer system for any reflector (VISAR) was recently deployed at the light initiated high explosive facility (LIHE) to measure the velocity of an explosively accelerated flyer plate. The velocity data from the flyer plate experiments, using the vendor's fringe constant of 100m/s/fringe, were consistently lower than model predictions. The goal of the VISAR validation test series was to confirm the VISAR system fringe constant. A low velocity gas gun was utilized to impact and accelerate a target at the LIHE facility. VISAR velocity data from the accelerated target was compared against an independent velocity measurement. The data from this test series did in fact reveal the fringe constant was significantly higher than the vendor's specification. The correct fringe constant for the LIHE VISAR system has been determined to be 123 m/s/fringe. The Light Initiated High Explosive (LIHE) facility recently completed a Phase I test series to develop an explosively accelerated flyer plate (X-Flyer). The X-Flyer impulse technique consists of first spraying a thin layer of silver acetylide silver nitrate explosive onto a thin flyer plate. The explosive is then initiated using an intense flash of light. The explosive detonation accelerates the flyer across a small air gap towards the test item. The impact of the flyer with the test item creates a shock pulse and an impulsive load in the test unit. The goal of Phase I of the X-Flyer development series was to validate the technique theory and design process. One of the key parameters that control the shock pulse and impulsive load is the velocity of the flyer at impact. To measure this key parameter, a velocity interferometer system for any reflector (VISAR) was deployed at the LIHE facility. The VISAR system was assembled by Sandia personnel from the Explosive Projects and Diagnostics department. The VISAR was a three leg, push-pull system using a fixed delay cavity. The primary optical components consisted of

  5. Characterisation and modification of thermally stable high explosives for laser flyer applications

    SciTech Connect

    Parker, A.; Claridge, R. P.; Johnson, N. A.; Proud, W. G.

    2007-12-12

    Laser initiation offers improved weapon survivability, versatility and greater Insensitive Munitions (IM) compliance. Detonators based on laser-driven flyers are less vulnerable to electrical initiation and can be based on insensitive secondary explosives. Additionally, this technology will offer advantages in terms of improved flexibility and reliability. Hexanitrostilbene (HNS) and nonanitro-m-terphenyl (NONA) were selected for investigation at QinetiQ as their increased thermal stability over conventional explosives makes them ideal candidates for use in insensitive munition compliant applications. The response of these materials to short duration high-amplitude shock impulses provided by exploding foil initiators (EFI), the electrical equivalent of a laser-driven flyer system, was investigated. Preparation techniques including sonication and the incorporation of additives were used to sensitize the materials to flyer impact, yet maintain their insensitivity to external hazards. Sonication significantly reduced the particle size of both HNS and NONA. The reduced-size explosives exhibited increased sensitivity to EFI impact than the starting materials.

  6. Nanoengineered explosives

    DOEpatents

    Makowiecki, D.M.

    1996-04-09

    A complex modulated structure is described for reactive elements that have the capability of considerably more heat than organic explosives while generating a working fluid or gas. The explosive and method of fabricating same involves a plurality of very thin, stacked, multilayer structures, each composed of reactive components, such as aluminum, separated from a less reactive element, such as copper oxide, by a separator material, such as carbon. The separator material not only separates the reactive materials, but it reacts therewith when detonated to generate higher temperatures. The various layers of material, thickness of 10 to 10,000 angstroms, can be deposited by magnetron sputter deposition. The explosive detonates and combusts a high velocity generating a gas, such as CO, and high temperatures. 2 figs.

  7. Nanoengineered explosives

    DOEpatents

    Makowiecki, Daniel M.

    1996-01-01

    A complex modulated structure of reactive elements that have the capability of considerably more heat than organic explosives while generating a working fluid or gas. The explosive and method of fabricating same involves a plurality of very thin, stacked, multilayer structures, each composed of reactive components, such as aluminum, separated from a less reactive element, such as copper oxide, by a separator material, such as carbon. The separator material not only separates the reactive materials, but it reacts therewith when detonated to generate higher temperatures. The various layers of material, thickness of 10 to 10,000 angstroms, can be deposited by magnetron sputter deposition. The explosive detonates and combusts a high velocity generating a gas, such as CO, and high temperatures.

  8. Residual absorption of high temperature superconductors at THz frequencies

    SciTech Connect

    Keller, P.; Barowski, H.S.; Prenninger, M.; Pechen, E.V.; Renk, K.F.

    1996-12-31

    The authors report on a study of the residual absorption of high temperature superconductors (HTS) at THz frequencies. Using transmission Fabry-Perot interferometry, they determined both, real and imaginary part of the conductivity. They especially studied YBCO thin films. They found that the dynamical conductivity varied strongly from sample to sample. As a main result, they find that the absorptivity increases at frequencies above 1 THz much weaker than quadratically, i.e., the {omega}{sup 2} behavior of the absorptivity at microwave frequencies is not continued in the THz frequency range.

  9. [Residual risk: The roles of triglycerides and high density lipoproteins].

    PubMed

    Grammer, Tanja; Kleber, Marcus; Silbernagel, Günther; Scharnagl, Hubert; März, Winfried

    2016-06-01

    In clinical trials, the reduction of LDL-cholesterol (LDL-C) with statins reduces the incidence rate of cardiovascular events by approximately one third. This means, that a sizeable "residual risk" remains. Besides high lipoprotein (a), disorders in the metabolism of triglyceride-rich lipoproteins and high density liproteins have been implicated as effectors of the residual risk. Both lipoprotein parameters correlate inversely with each other. Therefore, the etiological contributions of triglycerides and / or of HDL for developing cardiovascular disease can hardly be estimated from either observational studies or from intervention studies. The largely disappointing results of intervention studies with inhibitors of the cholesteryl ester transfer protein and in particular the available set of genetically-epidemiological studies suggest that in the last decade, the importance of HDL cholesterol has been overvalued, while the importance of triglycerides has been underestimated. High triglycerides not always atherogenic, but only if they are associated with the accumulation relatively cholesterol-enriched, incompletely catabolized remnants of chylomicrons and very low density lipoproteins (familial type III hyperlipidemia, metabolic syndrome, diabetes mellitus). The normalization of the concentration of triglycerides and remnants by inhibiting the expression of apolipoprotein C3 is hence a new, promising therapeutic target. PMID:27305303

  10. Extrusion cast explosive

    DOEpatents

    Scribner, K.J.

    1985-11-26

    Disclosed is an improved, multiphase, high performance, high energy, extrusion cast explosive compositions, comprising, a crystalline explosive material; an energetic liquid plasticizer; a urethane prepolymer, comprising a blend of polyvinyl formal, and polycaprolactone; a polyfunctional isocyanate; and a catalyst. These new explosive compositions exhibit higher explosive content, a smooth detonation front, excellent stability over long periods of storage, and lower sensitivity to mechanical stimulants. 1 fig.

  11. Extrusion cast explosive

    DOEpatents

    Scribner, K.J.

    1985-01-29

    Improved, multiphase, high performance, high energy, extrusion cast explosive compositions, comprising, a crystalline explosive material; an energetic liquid plasticizer; a urethane prepolymer, comprising a blend of polyvinyl formal, and polycaprolactone; a polyfunctional isocyanate; and a catalyst are disclosed. These new explosive compositions exhibit higher explosive content, a smooth detonation front, excellent stability over long periods of storage, and lower sensitivity to mechanical stimulants. 1 fig.

  12. Capabilities for high explosive pulsed power research at Los Alamos National Laboratory

    SciTech Connect

    Goforth, James H; Oona, Henn; Tasker, Douglas G; Kaul, A M

    2008-01-01

    Research on topics requiring high magnetic fields and high currents have been pursued using high explosive pulsed power (HEPP) techniques since the 1950s at Los Alamos National Laboratory. We have developed many sophisticated HEPr systems through the years, and most of them depend on technology available from the nuclear weapons program. Through the 1980s and 1990s, our budgets would sustain parallel efforts in zpinch research using both HEPr and capacitor banks. In recent years, many changes have occurred that are driven by concerns such as safety, security, and environment, as well as reduced budgets and downsizing of the National Nuclear Security Administration (NNSA) complex due to the end of the cold war era. In this paper, we review the teclmiques developed to date, and adaptations that are driven by changes in budgets and our changing complex. One new Ranchero-based solid liner z-pinch experimental design is also presented. Explosives that are cast to shape instead of being machined, and initiation systems that depend on arrays of slapper detonators are important new tools. Some materials that are seen as hazardous to the environment are avoided in designs. The process continues to allow a wide range of research however, and there are few, if any, experiments that we have done in the past that could not be perform today. The HErr firing facility at Los Alamos continues to have a 2000 lb. high explosive limit, and our 2.4 MJ capacitor bank remains a mainstay of the effort. Modem diagnostic and data analysis capabilities allow fewer personnel to achieve better results, and in the broad sense we continue to have a robust capability.

  13. Submillimeter residual losses in high-{Tc} superconductors

    SciTech Connect

    Miller, D.

    1993-09-01

    Bolometry was used obtain accurate submillimeter residual loss data for epitaxial films of YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO), Tl{sub 2}Ca{sub 2}Ba{sub 2}Cu{sub 3}O{sub 10}, Tl{sub 2}CaBa{sub 2}Cu{sub 2}O{sub 8} (TCBCO), and Ba{sub 0.6}K{sub 0.4}BiO{sub 3} (BKBO). We were able to fit the absorptivity measured for Nb films to an Eliashberg strong coupling calculation; excellent agreement resulted between parameters from best fits and measured Residual Resistivity Ratio. Microwave surface resistance measurements made on the same YBCO and TCBCO films are in excellent agreement with submillimeter measurements. Absorptivities for all YBCO films studied are qualitatively similar, increasing smoothly with frequency, with no gap-like features below the well known absorption edge at 450 cm{sup {minus}1}. Losses in YBCO films were fit to a weakly coupled grain model for the a-b plane conductivity. Strong phonon structure was observed in TCBCO films between 60 and 700 cm{sup {minus}1} (2 THz and 23 THz); these losses could not be fitted to the simple weakly coupled grain model, in contrast to the case for other high-{Tc} superconductors where phonon structure observed in ceramics are is absent in epitaxial oriented films and crystals because of electronic screening due to high conductivity of a-b planes. Absorptivity data for the BKBO films all show a strong absorption onset near the BCS tunneling gap of 3.5 k{sub B}{Tc}. Comparison with strong coupling Eliashberg predictions and of a Kramers-Kronig analysis indicate that the absorption onset is consistent with a superconducting energy gap. Effects of magnetic field on residual losses in YBCO films show a resonant absorption feature in vicinity of predicted

  14. Understanding highly explosive basaltic eruptions: Evidence from olivine-hosted melt inclusions from Sunset Crater, AZ

    NASA Astrophysics Data System (ADS)

    Allison, C. M.; Roggensack, K.; Clarke, A. B.; Alfano, F.

    2013-12-01

    Basaltic scoria cone volcanoes are the most abundant volcanic landform on Earth and occur in all tectonic settings. Basaltic magmas have lower viscosities, higher temperatures, and lower volatile contents than silicic magmas, and therefore generally have a lower potential for explosive activity. However, basaltic eruptions display great variability, from mild lava flows to more energetic explosions with large plumes. The mechanism controlling highly explosive basaltic eruptions, such as the ca. 1085 AD eruption of Sunset Crater, is poorly understood. Processes or conditions such as high volatile content in the source magma, injection of a compositionally distinct magma at depth, interaction with shallow magma reservoirs, or rapid crystallization and/or bubble nucleation in the shallow subsurface could increase explosivity of basaltic magmas. One method to test these hypotheses is melt inclusion analysis in order to constrain initial melt composition, volatile content and minimum storage depth. The San Francisco Volcanic Field (SFVF) in northern Arizona, active from 6 Ma-present, consists of over 600 volcanoes - mainly alkali basalt scoria cones along with five silicic centers. The eruption of Sunset Crater in the SFVF during the Holocene was an anomalously large basaltic explosive eruption, consisting of >8 explosive phases and 3 lava flows. Typical scoria cone-forming eruptions produce <0.1 km3 DRE of material, while the Sunset Crater tephra deposit is on the order of ~0.3 km3 DRE, with each phase characterized by volumes of 0.02-0.08 km3 DRE. The phases vary in size and style; the beginning stages of explosive activity (phases 1-2) were considerably smaller than phases 3-5, classified as subplinian. Because of the young age and desert setting of the volcano, the eruptive material is fresh and the deposit is well preserved. The bulk composition is an alkali basalt with Mg# 74. We studied 40 primary melt inclusions (MIs) hosted in 36 olivine crystals 0.5-2 mm in

  15. Laser photoacoustic spectroscopy helps fight terrorism: High sensitivity detection of chemical Warfare Agent and explosives

    NASA Astrophysics Data System (ADS)

    Patel, C. K. N.

    2008-01-01

    Tunable laser photoacoustic spectroscopy is maturing rapidly in its applications to real world problems. One of the burning problems of the current turbulent times is the threat of terrorist acts against civilian population. This threat appears in two distinct forms. The first is the potential release of chemical warfare agents (CWA), such as the nerve agents, in a crowded environment. An example of this is the release of Sarin by Aum Shinrikyo sect in a crowded Tokyo subway in 1995. An example of the second terrorist threat is the ever-present possible suicide bomber in crowded environment such as airports, markets and large buildings. Minimizing the impact of both of these threats requires early detection of the presence of the CWAs and explosives. Photoacoustic spectroscopy is an exquisitely sensitive technique for the detection of trace gaseous species, a property that Pranalytica has extensively exploited in its CO2 laser based commercial instrumentation for the sub-ppb level detection of a number of industrially important gases including ammonia, ethylene, acrolein, sulfur hexafluoride, phosphine, arsine, boron trichloride and boron trifluoride. In this presentation, I will focus, however, on our recent use of broadly tunable single frequency high power room temperature quantum cascade lasers (QCL) for the detection of the CWAs and explosives. Using external grating cavity geometry, we have developed room temperature QCLs that produce continuously tunable single frequency CW power output in excess of 300 mW at wavelengths covering 5 μm to 12 μm. I will present data that show a CWA detection capability at ppb levels with false alarm rates below 1:108. I will also show the capability of detecting a variety of explosives at a ppb level, again with very low false alarm rates. Among the explosives, we have demonstrated the capability of detecting homemade explosives such as triacetone triperoxide and its liquid precursor, acetone which is a common household

  16. Initial characterization of a highly contaminated high explosives outfall in preparation for in situ bioremediation

    SciTech Connect

    Betty A. Strietelmeier; Patrick J. Coyne; Patricia A. Leonard; W. Lamar Miller; Jerry R. Brian

    1999-12-01

    In situ bioremediation is a viable, cost-effective treatment for environmental contamination of many kinds. The feasibility of using biological techniques to remediate soils contaminated with high explosives (HE) requires laboratory evaluation before proceeding to a larger scale field operation. Laboratory investigations have been conducted at pilot scale which indicate that an anaerobic process could be successful at reducing levels of HE, primarily HMX, RDX and TNT, in contaminated soils. A field demonstration project has been designed to create an anaerobic environment for the degradation of HE materials. The first step in this project, initial characterization of the test area, was conducted and is the subject of this report. The levels of HE compounds found in the samples from the test area were higher than the EPA Method 8330 was able to extract without subsequent re-precipitation; therefore, a new method was developed using a superior extractant system. The test area sampling design was relatively simple as one might expect in an initial characterization. A total of 60 samples were each removed to a depth of 4 inches using a 1 inch diameter corer. The samples were spaced at relatively even intervals across a 20 foot cross-section through the middle of four 7-foot-long adjacent plots which are designed to be a part of an in situ bioremediation experiment. Duplicate cores were taken from each location for HE extraction and analysis in order to demonstrate and measure the heterogeneity of the contamination. Each soil sample was air dried and ball-milled to provide a homogeneous solid for extraction and analysis. Several samples had large consolidated pieces of what appeared to be solid HE. These were not ball-milled due to safety concerns, but were dissolved and the solutions were analyzed. The new extraction method was superior in that results obtained for several of the contaminants were up to 20 times those obtained with the EPA extraction method. The

  17. Explosive laser

    DOEpatents

    Robinson, C.P.; Jensen, R.J.; Davis, W.C.; Sullivan, J.A.

    1975-09-01

    This patent relates to a laser system wherein reaction products from the detonation of a condensed explosive expand to form a gaseous medium with low translational temperature but high vibration population. Thermal pumping of the upper laser level and de-excitation of the lower laser level occur during the expansion, resulting in a population inversion. The expansion may be free or through a nozzle as in a gas-dynamic configuration. In one preferred embodiment, the explosive is such that its reaction products are CO$sub 2$ and other species that are beneficial or at least benign to CO$sub 2$ lasing. (auth)

  18. High explosives vapor detection by atmospheric sampling glow discharge ionization/tandem mass spectrometry

    SciTech Connect

    McLuckey, S.A.; Goeringer, D.E.; Asano, K.G.

    1996-02-01

    The combination of atmospheric sampling glow discharge ionization with tandem mass spectrometry for the detection of traces of high explosives is described. Particular emphasis is placed on use of the quadrupole ion trap as the type of tandem mass spectrometer. Atmospheric sampling glow discharge provides a simple, rugged, and efficient means for anion formation while the quadrupole ion trap provides for efficient tandem mass spectrometry. Mass selective ion accumulation and non-specific ion activation methods can be used to overcome deleterious effects arising from ion/ion interactions. Such interactions constitute the major potential technical barrier to the use of the ion trap for real-time monitoring of targeted compounds in uncontrolled and highly variable matrices. Tailored waveforms can be used to effect both mass selective ion accumulation and ion activation. Concatenated tailored waveforms allow for both functions in a single experiment thereby providing the capability for monitoring several targeted species simultaneously. The combination of atmospheric sampling glow discharge ionization with a state-of-the-art analytical quadrupole ion trap is a highly sensitive and specific detector for traces of high explosives. The combination is also small and inexpensive relative to virtually any other form of tandem mass spectrometry. The science and technology underlying the glow discharge/ion trap combination is sufficiently mature to form the basis for an engineering effort to make the detector portable. 85 refs.

  19. Explosive complexes

    DOEpatents

    Huynh, My Hang V.

    2009-09-22

    Lead-free primary explosives of the formula [M.sup.II(A).sub.R(B.sup.X).sub.S](C.sup.Y).sub.T, where A is 1,5-diaminotetrazole, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

  20. Explosive complexes

    DOEpatents

    Huynh, My Hang V.

    2011-08-16

    Lead-free primary explosives of the formula [M.sup.II(A).sub.R(B.sup.X).sub.S](C.sup.Y).sub.T, where A is 1,5-diaminotetrazole, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

  1. Isentropic Compression Driven by High-Explosive Application to TI-6AL-4V

    NASA Astrophysics Data System (ADS)

    Voltz, C.; Sollier, A.; Maillet, J.-B.; Bouyer, V.

    2009-12-01

    We report on an isentropic compression experiment of Ti-6Al-4V alloy based on the use of the release of detonation products from a high-explosive to generate a ramp wave compression in a multisteps target. VISAR and DLI measurements of the rear free surface velocities of the different steps allow computing the sound velocity of the material during its compression, which is characteristic of the EOS of the material. The experimental device is described and the sound velocity measurements are analyzed. We obtain Ti-6Al-4V strength along the compression up to 15 GPa. The results are compared with two dimensional elastic-plastic simulations.

  2. A study of the role of homogeneous process in heterogeneous high explosives

    SciTech Connect

    Tang, P.K.

    1993-05-01

    In a new hydrodynamic formulation of shock-induced chemical reaction, we can show formally that the presence of certain homogenous reaction characteristics is becoming more evident as shock pressure increase even in heterogeneous high explosives. The homogeneous reaction pathway includes nonequilibrium excitation and deactivation stages prior to chemical reaction. The excitation process leads to an intermediate state at higher energy level than the equilibrium state, and as a result, the effective activation energy appears to be lower than the value based on thermal experiments. As the pressure goes up higher, the homogeneous reaction can even surpass the heterogeneous process and becomes the dominant mechanism.

  3. A study of the role of homogeneous process in heterogeneous high explosives

    SciTech Connect

    Tang, P.K.

    1993-01-01

    In a new hydrodynamic formulation of shock-induced chemical reaction, we can show formally that the presence of certain homogenous reaction characteristics is becoming more evident as shock pressure increase even in heterogeneous high explosives. The homogeneous reaction pathway includes nonequilibrium excitation and deactivation stages prior to chemical reaction. The excitation process leads to an intermediate state at higher energy level than the equilibrium state, and as a result, the effective activation energy appears to be lower than the value based on thermal experiments. As the pressure goes up higher, the homogeneous reaction can even surpass the heterogeneous process and becomes the dominant mechanism.

  4. Explosives signatures and analysis

    NASA Astrophysics Data System (ADS)

    Fountain, Augustus Way, III; Oyler, Jonathan M.; Ostazeski, Stanley A.

    2008-04-01

    The challenge of sampling explosive materials for various high threat military and civilian operational scenarios requires the community to identify and exploit other chemical compounds within the mixtures that may be available to support stand-off detection techniques. While limited surface and vapor phase characterization of IEDs exist, they are insufficient to guide the future development and evaluation of field deployable explosives detection (proximity and standoff) capabilities. ECBC has conducted a limited investigation of three artillery ammunition types to determine what chemical vapors, if any, are available for sensing; the relative composition of the vapors which includes the more volatile compounds in munitions, i.e., plastersizers and binders; and the sensitivity needed detect these vapors at stand-off. Also in partnership with MIT-Lincoln Laboratory, we performed a background measurement campaign at the National Training Center to determine the baseline ambient amounts and variability of nitrates and nitro-ester compounds as vapors, particulates, and on surfaces; as well as other chemical compounds related to non-energetic explosive additives. Environmental persistence studies in contexts relevant to counter-IED sensing operations, such as surface residues, are still necessary.

  5. Non-detonable explosive simulators

    DOEpatents

    Simpson, R.L.; Pruneda, C.O.

    1994-11-01

    A simulator which is chemically equivalent to an explosive, but is not detonable. The simulator has particular use in the training of explosives detecting dogs and calibrating sensitive analytical instruments. The explosive simulants may be fabricated by different techniques, a first involves the use of standard slurry coatings to produce a material with a very high binder to explosive ratio without masking the explosive vapor, and the second involves coating inert beads with thin layers of explosive molecules. 5 figs.

  6. Non-detonable explosive simulators

    DOEpatents

    Simpson, Randall L.; Pruneda, Cesar O.

    1994-01-01

    A simulator which is chemically equivalent to an explosive, but is not detonable. The simulator has particular use in the training of explosives detecting dogs and calibrating sensitive analytical instruments. The explosive simulants may be fabricated by different techniques, a first involves the use of standard slurry coatings to produce a material with a very high binder to explosive ratio without masking the explosive vapor, and the second involves coating inert beads with thin layers of explosive molecules.

  7. The Plumbing System of a Highly Explosive Basaltic Volcano: Sunset Crater, AZ

    NASA Astrophysics Data System (ADS)

    Allison, C. M.; Roggensack, K.; Clarke, A. B.

    2015-12-01

    We seek to better understand highly explosive basaltic eruptions with specific focus on magmatic volatile solubility in alkali basalts and the magma plumbing system. Sunset Crater, an alkali basalt (~3.7 wt.% alkalis) scoria cone volcano, erupted explosively in 1085 AD. We analyzed 125 primary melt inclusions (MIs) from Sunset Crater tephra deposited by 2 subplinian phases and 1 Strombolian explosion to compare magma volatiles and storage conditions. We picked rapidly quenched free olivine crystals and selected large volume MIs (50-180 μm) located toward crystal cores. MIs are faceted and exhibit little major element composition variability with minor post entrapment crystallization (2-10%). MIs are relatively dry but CO2-rich. Water content varies from 0.4 wt.% to 1.5 wt.% while carbon dioxide abundance ranges between 1,150 ppm and 3,250 ppm. Most MIs contain >1 wt.% H2O and >2,150 ppm CO2. All observed MIs contain a vapor bubble, so we are evaluating MI vapor bubbles with Raman spectroscopy and re-homogenization experiments to determine the full volatile budget. Because knowledge of volatile solubility is critical to accurately interpret results from MI analyses, we measured H2O-CO2 solubility in the Sunset Crater bulk composition. Fluid-saturated experiments at 4 and 6 kbar indicate shallower entrapment pressures for these MIs than values calculated for this composition using existing models. Assuming fluid saturation, MIs record depths from 6 km to 14 km, including groupings suggesting two pauses for longer-term storage at ~6 km and ~10.5 km. We do not observe any significant differences in MIs from phases exhibiting different eruptive styles, suggesting that while a high CO2 content may drive rapid magma ascent and be partly responsible for highly explosive eruptions, shallower processes may govern the final eruptive character. To track shallow processes during magma ascent from depth of MI-entrapment up to the surface, we are examining MI re-entrants.

  8. Infrared Scattering Scanning Near-Field Optical Microscopy Using An External Cavity Quantum Cascade Laser For Nanoscale Chemical Imaging And Spectroscopy of Explosive Residues

    SciTech Connect

    Craig, Ian M.; Phillips, Mark C.; Taubman, Matthew S.; Josberger, Erik E.; Raschke, Markus Bernd

    2013-02-04

    Infrared scattering scanning near-field optical microscopy (s-SNOM) is an apertureless superfocusing technique that uses the antenna properties of a conducting atomic force microscope (AFM) tip to achieve infrared spatial resolution below the diffraction limit. The instrument can be used either in imaging mode, where a fixed wavelength light source is tuned to a molecular resonance and the AFM raster scans an image, or in spectroscopy mode where the AFM is held stationary over a feature of interest and the light frequency is varied to obtain a spectrum. In either case, a strong, stable, coherent infrared source is required. Here we demonstrate the integration of a broadly tunable external cavity quantum cascade laser (ECQCL) into an s-SNOM and use it to obtain infrared spectra of microcrystals of chemicals adsorbed onto gold substrates. Residues of the explosive compound tetryl was deposited onto gold substrates. s-SNOM experiments were performed in the 1260-1400 cm-1 tuning range of the ECQCL, corresponding to the NO2 symmetric stretch vibrational fingerprint region. Vibrational infrared spectra were collected on individual chemical domains with a collection area of *500nm2 and compared to ensemble averaged far-field reflection-absorption infrared spectroscopy (RAIRS) results.

  9. Infrared scattering scanning near-field optical microscopy using an external cavity quantum cascade laser for nanoscale chemical imaging and spectroscopy of explosive residues

    NASA Astrophysics Data System (ADS)

    Craig, Ian M.; Phillips, Mark C.; Taubman, Matthew S.; Josberger, Erik E.; Raschke, Markus B.

    2013-01-01

    Infrared scattering scanning near-field optical microscopy (s-SNOM) is an apertureless superfocusing technique that uses the antenna properties of a conducting atomic force microscope (AFM) tip to achieve infrared spatial resolution below the diffraction limit. The instrument can be used either in imaging mode, where a fixed wavelength light source is tuned to a molecular resonance and the AFM raster scans an image, or in spectroscopy mode where the AFM is held stationary over a feature of interest and the light frequency is varied to obtain a spectrum. In either case, a strong, stable, coherent infrared source is required. Here we demonstrate the integration of a broadly tunable external cavity quantum cascade laser (ECQCL) into an s-SNOM and use it to obtain infrared spectra of microcrystals of chemicals adsorbed onto gold substrates. Residues of the explosive compound tetryl was deposited onto gold substrates. s-SNOM experiments were performed in the 1260-1400cm-1 tuning range of the ECQCL, corresponding to the N02 symmetric stretch vibrational fingerprint region. Vibrational infrared spectra were collected on individual chemical domains with a collection area of ~500 nm2 and compared to ensemble averaged far-field reflection-absorption infrared spectroscopy (RAIRS) results.

  10. The Use of Explosive Energy for Joining Advanced High Strength Low Alloy Steels

    NASA Astrophysics Data System (ADS)

    Urbánek, Miroslav; Mašek, Bohuslav; Hronek, Pavel; Nesvadba, Petr

    2013-03-01

    This article deals with an alternative method of joining advanced steels for frame structures. These steels cannot be joined by a conventional process due to the impact of temperature on the base material. Therefore, a simple and cost-effective method of forming a high-strength joint, intended for advanced high-strength materials, was designed using explosive forming. One of its key advantages is that it preserves the microstructure of the high-strength material being joined. At the same time, the design of the joint allows it to undergo further plastic deformation if the yield stress is exceeded, thus preventing the step change in load-carrying capacity and the instability of the structure. The alternative joint was intended for materials with yield stress above 1000 MPa and elongation of 10%, under quasi-static conditions. However, the design is also suitable for materials with ultimate tensile strength higher than 2000 MPa. Testing of the load-carrying capacity of the joint in a mechanical testing shop showed that the larger the flow stress of the material, the higher the load-carrying capacity of the joint. The selected joint designs with good load-bearing capacity values were manufactured by forming using products of detonation of the SEMTEX industrial blasting explosive. In a compression test, the demonstration joints showed the axial load-bearing capacity of 200 kN with up to 20-mm displacement to failure.

  11. Deflagration Behavior of HMX-Based Explosives at High Temperatures and Pressures

    SciTech Connect

    Maienschein, J L; Wardell, J F

    2003-11-20

    We report the deflagration behavior of several HMX-based explosives at pressure from 10-600 MPa and temperatures from 20-180 C. We have made laminar burn rate measurements with the LLNL High Pressure Strand Burner, in which burn wires are used to record the time-of-arrival of the burn front in the cylindrical sample as a function of pressure. The explosive samples are 6.4 mm in diameter and 63 mm long, with ten burn wires embedded at different positions in the sample. Burning on the cylindrical surface is inhibited with an epoxy layer. With this direct measurement we do not have to account for product gas equation of state or heat losses in the system, and the burn wires allow detection of irregular burning. We find that formulation details are very important to overall deflagration behavior - the presence of 10% or less by weight of binder leads to physical deconsolidation and rapid deflagration at high pressures, and a larger particle size distribution leads to slower deflagration. High temperatures have a relatively minor effect on the deflagration rate until the beta-to-delta phase transition temperature is reached, beyond which the deflagration rate increases approximately 40-fold.

  12. Deflagration of HMX-Based Explosives at High Temperatures and Pressures

    SciTech Connect

    Maienschein, J L; Wardell, J F; DeHaven, M R; Black, C K

    2004-05-12

    We measure the deflagration behavior of energetic materials at extreme conditions (up to 520K and 1 GPa) in the LLNL High Pressure Strand Burner, thereby obtaining reaction rate data for prediction of violence of thermal explosions. The apparatus provides both temporal pressure history and flame time-of-arrival information during deflagration, allowing direct calculation of deflagration rate as a function of pressure. Samples may be heated before testing. Here we report the deflagration behavior of several HMX-based explosives at pressures of 10-600 MPa and temperatures of 300-460 K. We find that formulation details are very important to overall deflagration behavior. Formulations with high binder content (>15 wt%) deflagrate smoothly over the entire pressure range regardless of particle size, with a larger particle size distribution leading to a slower reaction. The deflagration follows a power law function with the pressure exponent being unity. Formulations with lower binder content ({le} 10% or less by weight) show physical deconsolidation at pressures over 100-200 MPA, with transition to a rapid erratic deflagration 10-100 times faster. High temperatures have a relatively minor effect on the deflagration rate until the HMX {beta} {yields} {delta} phase transition occurs, after which the deflagration rate increases by more than a factor of 10.

  13. Producing high sugar concentrations from loblolly pine using wet explosion pretreatment.

    PubMed

    Rana, Diwakar; Rana, Vandana; Ahring, Birgitte K

    2012-10-01

    We present quantitative analysis of pretreatment for obtaining high conversion and release of sugars from loblolly pine. We use wet explosion (WEx): wet oxidation followed by steam explosion and enzymatic hydrolysis (EH) at high dry matter to solubilize sugars. WEx was conducted at 25% (w/w) solids in presence of oxygen at pressures 6.5-7.2 bar, temperatures 170-175°C and residence time from 20 to 22.5 min. EH of pretreated samples was performed by Cellic® Ctec2 (60 mg protein/g cellulose) and Cellic® Htec2 enzymes (10% of Ctec2) at 50°C for 72 h. At the optimal WEx condition 96% cellulose and nearly 100% hemicellulose yield were obtained. The final concentrations of monomeric sugars were 152 g/L of glucose, 67 g/L of xylose, and 67 g/L of minor sugars (galactose, arabinose and mannose). Compared to previous work WEx seems to be superior for releasing high concentrations of monomeric sugars. PMID:22854131

  14. THE APPLICATION OF SINGLE PARTICLE AEROSOL MASS SPECTROMETRY FOR THE DETECTION AND IDENTIFICATION OF HIGH EXPLOSIVES AND CHEMICAL WARFARE AGENTS

    SciTech Connect

    Martin, A

    2006-10-23

    Single Particle Aerosol Mass Spectrometry (SPAMS) was evaluated as a real-time detection technique for single particles of high explosives. Dual-polarity time-of-flight mass spectra were obtained for samples of 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazinane (RDX), and pentaerythritol tetranitrate (PETN); peaks indicative of each compound were identified. Composite explosives, Comp B, Semtex 1A, and Semtex 1H were also analyzed, and peaks due to the explosive components of each sample were present in each spectrum. Mass spectral variability with laser fluence is discussed. The ability of the SPAMS system to identify explosive components in a single complex explosive particle ({approx}1 pg) without the need for consumables is demonstrated. SPAMS was also applied to the detection of Chemical Warfare Agent (CWA) simulants in the liquid and vapor phases. Liquid simulants for sarin, cyclosarin, tabun, and VX were analyzed; peaks indicative of each simulant were identified. Vapor phase CWA simulants were adsorbed onto alumina, silica, Zeolite, activated carbon, and metal powders which were directly analyzed using SPAMS. The use of metal powders as adsorbent materials was especially useful in the analysis of triethyl phosphate (TEP), a VX stimulant, which was undetectable using SPAMS in the liquid phase. The capability of SPAMS to detect high explosives and CWA simulants using one set of operational conditions is established.

  15. In-situ Raman spectroscopy and high-speed photography of a shocked triaminotrinitrobenzene based explosive

    SciTech Connect

    Saint-Amans, C.; Hébert, P. Doucet, M.; Resseguier, T. de

    2015-01-14

    We have developed a single-shot Raman spectroscopy experiment to study at the molecular level the initiation mechanisms that can lead to sustained detonation of a triaminotrinitrobenzene-based explosive. Shocks up to 30 GPa were generated using a two-stage laser-driven flyer plate generator. The samples were confined by an optical window and shock pressure was maintained for at least 30 ns. Photon Doppler Velocimetry measurements were performed at the explosive/window interface to determine the shock pressure profile. Raman spectra were recorded as a function of shock pressure and the shifts of the principal modes were compared to static high-pressure measurements performed in a diamond anvil cell. Our shock data indicate the role of temperature effects. Our Raman spectra also show a progressive extinction of the signal which disappears around 9 GPa. High-speed photography images reveal a simultaneous progressive darkening of the sample surface up to total opacity at 9 GPa. Reflectivity measurements under shock compression show that this opacity is due to a broadening of the absorption spectrum over the entire visible region.

  16. In-situ Raman spectroscopy and high-speed photography of a shocked triaminotrinitrobenzene based explosive

    NASA Astrophysics Data System (ADS)

    Saint-Amans, C.; Hébert, P.; Doucet, M.; de Resseguier, T.

    2015-01-01

    We have developed a single-shot Raman spectroscopy experiment to study at the molecular level the initiation mechanisms that can lead to sustained detonation of a triaminotrinitrobenzene-based explosive. Shocks up to 30 GPa were generated using a two-stage laser-driven flyer plate generator. The samples were confined by an optical window and shock pressure was maintained for at least 30 ns. Photon Doppler Velocimetry measurements were performed at the explosive/window interface to determine the shock pressure profile. Raman spectra were recorded as a function of shock pressure and the shifts of the principal modes were compared to static high-pressure measurements performed in a diamond anvil cell. Our shock data indicate the role of temperature effects. Our Raman spectra also show a progressive extinction of the signal which disappears around 9 GPa. High-speed photography images reveal a simultaneous progressive darkening of the sample surface up to total opacity at 9 GPa. Reflectivity measurements under shock compression show that this opacity is due to a broadening of the absorption spectrum over the entire visible region.

  17. Multiphysics Simulations of Hot-Spot Initiation in Shocked Insensitive High-Explosive

    NASA Astrophysics Data System (ADS)

    Najjar, Fady; Howard, W. M.; Fried, L. E.

    2010-11-01

    Solid plastic-bonded high-explosive materials consist of crystals with micron-sized pores embedded. Under mechanical or thermal insults, these voids increase the ease of shock initiation by generating high-temperature regions during their collapse that might lead to ignition. Understanding the mechanisms of hot-spot initiation has significant research interest due to safety, reliability and development of new insensitive munitions. Multi-dimensional high-resolution meso-scale simulations are performed using the multiphysics software, ALE3D, to understand the hot-spot initiation. The Cheetah code is coupled to ALE3D, creating multi-dimensional sparse tables for the HE properties. The reaction rates were obtained from MD Quantum computations. Our current predictions showcase several interesting features regarding hot spot dynamics including the formation of a "secondary" jet. We will discuss the results obtained with hydro-thermo-chemical processes leading to ignition growth for various pore sizes and different shock pressures.

  18. THz Dielectric Properties of High Explosives Calculated by Density Functional Theory for the Design of Detectors

    NASA Astrophysics Data System (ADS)

    Shabaev, A.; Lambrakos, S. G.; Bernstein, N.; Jacobs, V.; Finkenstadt, D.

    2011-12-01

    The current need for better detection of explosive devices has imposed a new necessity for determining the dielectric response properties of energetic materials with respect to electromagnetic wave excitation. Among the range of different frequencies for electromagnetic excitation, the THz frequency range is of particular interest because of its nondestructive nature and ability to penetrate materials that are characteristic of clothing. Typically, the dielectric response properties for electromagnetic wave excitation at THz frequencies, as well as at other frequencies, are determined by means of experimental measurements. The present study, however, emphasizes that density functional theory (DFT), and associated software technology, is sufficiently mature for the determination of dielectric response functions, and actually provides complementary information to that obtained from experiment. In particular, these dielectric response functions provide quantitative initial estimates of spectral response features that can be adjusted with respect to additional information such as laboratory measurements and other types of theory-based calculations, as well as providing for the molecular level interpretation of response structure. This point is demonstrated in the present study by calculations of ground-state resonance structure associated with the high explosives RDX, TNT1, and TNT2 using DFT, which is for the construction of parameterized dielectric response functions for excitation by electromagnetic waves at frequencies within the THz range. The DFT software NRLMOL was used for the calculations of ground-state resonance structure presented here.

  19. Numerical investigation of the density effect in modeling detonation propagation in high explosives

    NASA Astrophysics Data System (ADS)

    Chiquete, Carlos; Meyer, Chad D.; Short, Mark

    2015-11-01

    Detonation Shock Dynamics (DSD) is an asymptotically-derived detonation propagation model used in engineering models of high explosive (HE) performance. The method is based on the limit where the detonation reaction zone length and time scales are small in relation to the much larger geometry in which the HE is embedded. The intrinsic DSD propagation law (functionally relating the surface normal velocity and curvature) for each HE is typically calibrated to simplified geometry tests where steady-state front velocities and shapes are measured. This relationship is necessarily a function of the experimental conditions and is thus limited in scope. For HE's with variable pressing or casting density, a particular need exists for calibrations sensitive to this variability. However, there is little constraint on how the density effect is specifically incorporated into the fitting procedure. To investigate this issue, shock-attached calculations in simple slab or cylindrical geometries are performed for varying initial density for a ``numerical'' explosive model with a realistic equation of state. The steady-state detonation velocities, front shapes and the resulting DSD calibration of this generated data are analyzed as function of the applied HE density.

  20. 1,5-Di(nitramino)tetrazole: High Sensitivity and Superior Explosive Performance.

    PubMed

    Fischer, Dennis; Klapötke, Thomas M; Stierstorfer, Jörg

    2015-08-24

    Highly energetic 1,5-di(nitramino)tetrazole and its salts were synthesized. The neutral compound is very sensitive and one of the most powerful non-nuclear explosives to date. Selected nitrogen-rich and metal salts were prepared. The potassium salt can be used as a sensitizer in place of tetracene. The obtained compounds were characterized by low-temperature X-ray diffraction, IR and Raman spectroscopy, multinuclear NMR spectroscopy, elemental analysis, and DSC. Calculated energetic performances using the EXPLO5 code based on calculated (CBS-4M) heats of formation and X-ray densities support the high energetic performances of the 1,5-dinitraminotetrazolates as energetic materials. The sensitivities towards impact, friction, and electrostatic discharge were also explored. PMID:26095124

  1. Preliminary experiments using light-initiated high explosive for driving thin flyer plates. [SASN

    SciTech Connect

    Benham, R.A.

    1980-02-01

    Light-initiated high explosive, silver acelytide - silver-nitrate (SASN), has been used to produce simulated x ray blow-off impulse loading on reentry vehicles to study the system structural response. SASN can be used to accelerate thin flyer plates to high terminal velocities which, in turn, can deliver a pressure pulse that can be tailored to the target material. This process is important for impulse tests where both structural and material response is desired. The theories used to calculate the dynamic state of the flyer plate prior to impact are summarized. Data from several experiments are presented which indicate that thin flyer plates can be properly accelerated and that there are predictive techniques available which are adequate to calculate the motion of the flyer plate. Recommendations are made for future study that must be undertaken to make the SASN flyer plate technique usable.

  2. New 100 mm Gun Assembly Installation at Lawrence Livermore National Laboratory High Explosives Applications Facility

    SciTech Connect

    Vandersall, K S; Lee, R A; Chiao, P I; Garcia, F; Travis, J O; Forbes, J W

    2003-10-28

    A new 100mm gun assembly was recently installed and tested at Lawrence Livermore National Laboratories located in the High Explosives Applications Facility (HEAF). Thiot Ingenierie performed the design of the replacement barrel, based on improvements to the initial design. This design incorporated barrel and breech sections forged from CLARM series high-strength alloys obtained from Tecphy Corporation and machined by Manufacture de Forage. Part of the improvement of the design was implementing a laser alignment system for quick and accurate barrel alignment checks. This laser is also used to align the target assembly. This paper will detail the design changes incorporated into the installation, the testing process, and future direction of research for the new gun.

  3. Computational study of 3-D hot-spot initiation in shocked insensitive high-explosive

    NASA Astrophysics Data System (ADS)

    Najjar, F. M.; Howard, W. M.; Fried, L. E.; Manaa, M. R.; Nichols, A., III; Levesque, G.

    2012-03-01

    High-explosive (HE) material consists of large-sized grains with micron-sized embedded impurities and pores. Under various mechanical/thermal insults, these pores collapse generating hightemperature regions leading to ignition. A hydrodynamic study has been performed to investigate the mechanisms of pore collapse and hot spot initiation in TATB crystals, employing a multiphysics code, ALE3D, coupled to the chemistry module, Cheetah. This computational study includes reactive dynamics. Two-dimensional high-resolution large-scale meso-scale simulations have been performed. The parameter space is systematically studied by considering various shock strengths, pore diameters and multiple pore configurations. Preliminary 3-D simulations are undertaken to quantify the 3-D dynamics.

  4. Research topics in explosives - a look at explosives behaviors

    NASA Astrophysics Data System (ADS)

    Maienschein, J. L.

    2014-05-01

    The behaviors of explosives under many conditions - e.g., sensitivity to inadvertent reactions, explosion, detonation - are controlled by the chemical and physical properties of the explosive materials. Several properties are considered for a range of improvised and conventional explosives. Here I compare these properties across a wide range of explosives to develop an understanding of explosive behaviors. For improvised explosives, which are generally heterogeneous mixtures of ingredients, a range of studies is identified as needed to more fully understand their behavior and properties. For conventional explosives, which are generally comprised of crystalline explosive molecules held together with a binder, I identify key material properties that determine overall sensitivity, including the extremely safe behavior of Insensitive High Explosives, and discuss an approach to predicting the sensitivity or insensitivity of an explosive.

  5. Investigation into low-temperatures influence on high explosive compounds sensitivity to shock-wave impacts

    SciTech Connect

    Averin, A.N.; Alekseev, A.V.; Batalov, S.V.; Loboiko, B.G.; Litvinov, B.V.; Sumin, V.D.; Filin, V.P.; Yagnakov, A.N.

    1996-05-01

    Study of shock-wave sensitivity of explosives under various temperatures is of great significance for correct analysis of safe application of different industrial processes, technologies, as well as for correct understanding of explosion initiation mechanism in (explosives). Currently, the influence of low, ({minus}100{degree}C{hor_ellipsis}{minus}200{degree}C) temperatures on explosive sensitivity to weak shock waves is poorly studied. This paper gives experimental results on the influence of low temperatures on the sensitivity of HMX{emdash}based explosives to weak shock-waves. In the present paper an attempt is made to experimentally determine dependence of HMX{emdash}based explosive sensitivity to weak shock waves on temperatures. The original technique of the experiment is presented in the report. {copyright} {ital 1996 American Institute of Physics.}

  6. Harvesting materials formed under extreme conditions: Synthesis and isolation of nanocarbons derived from detonation of high explosives

    NASA Astrophysics Data System (ADS)

    Firestone, Millicent; Ringstrand, Bryan; Huber, Rachel; Dattelbaum, Dana; Gustavson, Richard; Podlesak, David

    High explosive detonation products are primarily composed of molecular gases and solid carbon products. Recent studies have shown that the solid carbon condensate morphologies can vary depending on the high explosive and / or the pressure, temperature, or environment of the detonation. These studies have revealed, for example, unique carbon nanoparticles possessing novel morphologies, such as ones composed of hollow cores surrounded by lamellar structured graphitic shells. Despite these observations little work has been done to isolate these particles from the recovered post-detonation soot. This lack of effort to isolate and purify these products limits our understanding of their materials properties and, ultimately our ability to adapt them for useful materials. Herein, we report our recent studies directed at the production of nano-carbons through the detonation of a high explosive (e.g., composition B) under a range of experimental conditions. We further describe work directed at isolation and purification of the carbon nanoparticles.

  7. Enhanced mass removal due to phase explosion during high irradiance nanosecond laser ablation of silicon

    SciTech Connect

    Yoo, Jong Hyun

    2000-05-20

    The morphology of craters resulting from high irradiance laser ablation of silicon was measured using a white light interferometry microscope. The craters show a dramatic increase in their depth and volume at a certain irradiance, indicating a change in the primary mechanism for mass removal. Laser shadowgraph imaging was used to characterize and differentiate the mass ejection processes for laser irradiances above and below the threshold value. Time-resolved images show distinct features of the mass ejected at irradiances above the threshold value including the presence of micron-sized particulates; this begins at approximately 300 {approx} 400 ns after the start of laser heating. The analysis of the phenomena was carried out by using two models: a thermal evaporation model and a phase explosion model. Estimation of the crater depth due to the thermally evaporated mass led to a large underestimation of the crater depth for irradiances above the threshold. Above the threshold irradiance, the possibility of phase explosion was analyzed. Two important results are the thickness of the superheated liquid layer that is close to the critical temperature and the time for vapor bubbles that are generated in the superheated liquid to achieve a critical size. After reaching the critical size, vapor bubbles can grow spontaneously resulting in a violent ejection of liquid droplets from the superheated volume. The effects of an induced transparency, i.e. of liquid silicon turning into an optically transparent liquid dielectric medium, are also introduced. The estimated time for a bubble to reach the critical size is in agreement with the delay time measured for the initiation of large mass ejection. Also, the thickness of the superheated liquid layer that is close to the critical temperature at the time of the beginning of the large mass ejection is representative of the crater depth at the threshold irradiance. These results suggest that phase explosion is a plausible thermal

  8. High vacuum for containing the blast and radioactive particulate from improvised nuclear devices or explosive radioactive dispersal devices

    SciTech Connect

    Dyckes, G.W.

    1980-07-01

    The problems associated with using a source of high vacuum for attenuating the shock overpressure from uncontained explosive devices were explored. Calculations and the experiments cited revealed that practical difficulties exist in achieving high vacuums in sufficient volume to produce significant decreases in peak shock wave overpressures.

  9. High-Speed Photographic Experiments To Investigate The Effects Of Booster Housing Geometry On The Detonability Of Secondary Explosives

    NASA Astrophysics Data System (ADS)

    Hutchinson, C. D.

    1985-02-01

    Warheads in conventional munitions contain three explosive components - a detonator, an augmenting charge known as a booster and a main filling. High-speed photographic experiments have indicated that a significant improvement in the initiating ability of boosters can be obtained if minor modifications are made to their containers, or housings. It is shown that in the situation where an aluminium alloy booster housing is inserted into a recess in the main filling, enhanced radial initiation can be achieved. This is especially welcome where insensitive plastic bonded high explosives are used as main charge fillings.

  10. A thermalized ion explosion model for high energy sputtering and track registration

    NASA Technical Reports Server (NTRS)

    Seiberling, L. E.; Griffith, J. E.; Tombrello, T. A.

    1980-01-01

    A velocity spectrum of neutral sputtered particles as well as a low resolution mass spectrum of sputtered molecular ions was measured for 4.74 MeV F-19(+2) incident of UF4. The velocity spectrum is dramatically different from spectra taken with low energy (keV) bombarding ions, and is shown to be consistent with a hot plasma of atoms in thermal equilibrium inside the target. A thermalized ion explosion model is proposed for high energy sputtering which is expected to describe track formation in dielectric materials. The model is shown to be consistent with the observed total sputtering yield and the dependence of the yield on the primary ionization rate of the incident ion.

  11. Lightning Protection Certification for High Explosives Facilities at Lawrence Livermore National Laboratory

    SciTech Connect

    Clancy, T J; Brown, C G; Ong, M M; Clark, G A

    2006-01-11

    Presented here is an innovation in lighting safety certification, and a description of its implementation for high explosives processing and storage facilities at Lawrence Livermore National Laboratory. Lightning rods have proven useful in the protection of wooden structures; however, modern structures made of rebar, concrete, and the like, require fresh thinking. Our process involves a rigorous and unique approach to lightning safety for modern buildings, where the internal voltages and currents are quantified and the risk assessed. To follow are the main technical aspects of lightning protection for modern structures and these methods comply with the requirements of the National Fire Protection Association, the National Electrical Code, and the Department of Energy [1][2]. At the date of this release, we have certified over 70 HE processing and storage cells at our Site 300 facility.

  12. High-energy particle acceleration by explosive electromagnetic interaction in an accretion disk

    NASA Technical Reports Server (NTRS)

    Haswell, C. A.; Tajima, T.; Sakai, J.-I.

    1992-01-01

    By examining electromagnetic field evolution occurring in an accretion disk around a compact object, we arrive at an explosive mechanism of particle acceleration. Flux-freezing in the differentially rotating disk causes the seed and/or generated magnetic field to wrap up tightly, becoming highly sheared and locally predominantly azimuthal in orientation. We show how asymptotically nonlinear solutions for the electromagnetic fields may arise in isolated plasma blobs as a result of the driving of the fluid equations by the accretion flow. These fields are capable of rapidly accelerating charged particles from the disk. Acceleration through the present mechanism from AGN can give rise to energies beyond 10 exp 20 eV. Such a mechanism may present an explanation for the extragalactic origin of the most energetic observed cosmic rays.

  13. Deflagration Rate Measurements of Three Insensitive High Explosives: LLM-105, TATB, and DAAF

    SciTech Connect

    Glascoe, E A; Maienschein, J L; Lorenz, K T; Tan, N; Koerner, J G

    2010-03-08

    The pressure dependent deflagration rates of LLM-105, DAAF and TATB based formulations were measured in the LLNL high pressure strand burner. The role of binder amount, explosive type, and thermal damage and their effects on the deflagration rate will be discussed. One DAAF formulation, two different formulations of LLM-105, and four formulations of TATB were studied; results indicate that binder amount and type play a minor role in the deflagration behavior. This is in sharp contrast to the HMX based formulations which strongly depend on binder amount and type. The effect of preheating these samples was considerably more dramatic. In the case of LLM-105, preheating the sample appears to have little effect on the deflagration rate. In contrast, preheating DAAF and TATB formulations causes the deflagration rate to accelerate. The thermal and mechanical properties of these formulations will be discussed in the context of their pressure and temperature dependent deflagration rates.

  14. Remedial investigation of the High-Explosives (HE) Process Area, Lawrence Livermore National Laboratory Site 300

    SciTech Connect

    Crow, N.B.; Lamarre, A.L.

    1990-08-01

    This report presents the results of a Remedial Investigation (RI) to define the extent of high explosives (HE) compounds and volatile organic compounds (VOCs) found in the soil, rocks, and ground water of the HE Process Area of Lawrence Livermore National Laboratory's (LLNL) Site 300 Facility. The report evaluates potential public health environmental risks associated with these compounds. Hydrogeologic information available before February 15, 1990, is included; however, chemical analyses and water-level data are reported through March 1990. This report is intended to assist the California Regional Water Quality Control Board (RWQCB)--Central Valley Region and the US Environmental Protection Agency (EPA) in evaluating the extent of environmental contamination of the LLNL HE Process Area and ultimately in designing remedial actions. 90 refs., 20 figs., 7 tabs.

  15. On beyond the standard model for high explosives: challenges & obstacles to surmount

    SciTech Connect

    Menikoff, Ralph Ds

    2009-01-01

    Plastic-bonded explosives (PBX) are heterogeneous materials. Nevertheless, current explosive models treat them as homogeneous materials. To compensate, an empirically determined effective burn rate is used in place of a chemical reaction rate. A significant limitation of these models is that different burn parameters are needed for applications in different regimes; for example, shock initiation of a PBX at different initial temperatures or different initial densities. This is due to temperature fluctuations generated when a heterogeneous material is shock compressed. Localized regions of high temperatures are called hot spots. They dominate the reaction for shock initiation. The understanding of hot spot generation and their subsequent evolution has been limited by the inability to measure transients on small spatial ({approx} 1 {micro}m) and small temporal ({approx} 1 ns) scales in the harsh environment of a detonation. With the advances in computing power, it is natural to try and gain an understanding of hot-spot initiation with numerical experiments based on meso-scale simulations that resolve material heterogeneities and utilize realistic chemical reaction rates. However, to capture the underlying physics correctly, such high resolution simulations will require more than fast computers with a large amount of memory. Here we discuss some of the issues that need to be addressed. These include dissipative mechanisms that generate hot spots, accurate thermal propceties for the equations of state of the reactants and products, and controlling numerical entropy error from shock impedance mismatches at material interfaces. The later can generate artificial hot spots and lead to premature reaction. Eliminating numerical hot spots is critical for shock initiation simulations due to the positive feedback between the energy release from reaction and the hydrodynamic flow.

  16. A case study of a transported bromine explosion event in the Canadian high arctic

    NASA Astrophysics Data System (ADS)

    Zhao, X.; Strong, K.; Adams, C.; Schofield, R.; Yang, X.; Richter, A.; Friess, U.; Blechschmidt, A.-M.; Koo, J.-H.

    2016-01-01

    Ozone depletion events in the polar troposphere have been linked to extremely high concentrations of bromine, known as bromine explosion events (BEE). However, the optimum meteorological conditions for the occurrence of these events remain uncertain. On 4-5 April 2011, a combination of both blowing snow and a stable shallow boundary layer was observed during a BEE at Eureka, Canada (86.4°W, 80.1°N). Measurements made by a Multi-Axis Differential Optical Absorption Spectroscopy spectrometer were used to retrieve BrO profiles and partial columns. During this event, the near-surface BrO volume mixing ratio increased to ~20 parts per trillion by volume, while ozone was depleted to ~1 ppbv from the surface to 700 m. Back trajectories and Global Ozone Monitoring Experiment-2 satellite tropospheric BrO columns confirmed that this event originated from a bromine explosion over the Beaufort Sea. From 30 to 31 March, meteorological data showed high wind speeds (24 m/s) and elevated boundary layer heights (~800 m) over the Beaufort Sea. Long-distance transportation (~1800 km over 5 days) to Eureka indicated strong recycling of BrO within the bromine plume. This event was generally captured by a global chemistry-climate model when a sea-salt bromine source from blowing snow was included. A model sensitivity study indicated that the surface BrO at Eureka was controlled by both local photochemistry and boundary layer dynamics. Comparison of the model results with both ground-based and satellite measurements confirmed that the BEE observed at Eureka was triggered by transport of enhanced BrO from the Beaufort Sea followed by local production/recycling under stable atmospheric shallow boundary layer conditions.

  17. Analysis on explosive welded Al/Mg plates in as-received state and after heat treatment using the in situ high-energy X-ray diffraction

    NASA Astrophysics Data System (ADS)

    Zhou, Qiang; Chen, Pengwan; Nie, Zhihua; Lan, Yazhu

    2015-06-01

    The synchrotron-based HEXRD method has a much better angular resolution in the reciprocal space than neutron or traditional laboratory XRD, which creates an opportunity that could precisely study the crystal structure and parameter from the XRD pattern. Due to the high penetration depth of high-energy X-ray, the micro-strain and phase distribution could be determined precisely. In this work, the explosive welded 2024 Al/AZ31 Mg plates, both in as-received state and after heat treatment, were investigated by HEXRD method. The XRD patterns were taken shot-by-shot, going from Al to Mg with step width of 0.1mm. The micro-strain, phase distribution and grain size of each step were estimated and analyzed within the general mechanism of explosive welding. It is interesting to find that the intense texture observed in both cladded and base materials disappeared at the welded interface. Residual stress, which was obviously detected at the interface for the as-received sample, was eliminated after heat treatment. For the as-received sample, the strain of Mg along the path from interface to free surface was different for different Azimuth angle and different crystal orientation; but such variations didn't occur for Al.

  18. Application of solid sorbent collection techniques and high performance liquid chromatography with electrochemical detection to the analysis of explosives in water samples: Final report

    SciTech Connect

    Maskarinec, M.P.; Manning, D.L.; Harvey, R.W.

    1986-11-01

    Methods were developed for the determination of several explosives components (nitro-organic compounds) in environmental waters. The methods are based on Porapak resin adsorption and Amberlite XAD-4 resin adsorption of the explosives components from aqueous samples. Following desorption with acetone, the explosives are measured by high performance liquid chromatography with electrochemical detection. The technique provides a high degree of selectivity and sensitivity for these compounds in actual samples. Detection limits approach 1 ..mu..g/l for many components.

  19. Explosives tester

    DOEpatents

    Haas, Jeffrey S.; Howard, Douglas E.; Eckels, Joel D.; Nunes, Peter J.

    2011-01-11

    An explosives tester that can be used anywhere as a screening tool by non-technical personnel to determine whether a surface contains explosives. First and second explosives detecting reagent holders and dispensers are provided. A heater is provided for receiving the first and second explosives detecting reagent holders and dispensers.

  20. Nuclear explosive safety study process

    SciTech Connect

    1997-01-01

    Nuclear explosives by their design and intended use require collocation of high explosives and fissile material. The design agencies are responsible for designing safety into the nuclear explosive and processes involving the nuclear explosive. The methodology for ensuring safety consists of independent review processes that include the national laboratories, Operations Offices, Headquarters, and responsible Area Offices and operating contractors with expertise in nuclear explosive safety. A NES Study is an evaluation of the adequacy of positive measures to minimize the possibility of an inadvertent or deliberate unauthorized nuclear detonation, high explosive detonation or deflagration, fire, or fissile material dispersal from the pit. The Nuclear Explosive Safety Study Group (NESSG) evaluates nuclear explosive operations against the Nuclear Explosive Safety Standards specified in DOE O 452.2 using systematic evaluation techniques. These Safety Standards must be satisfied for nuclear explosive operations.

  1. Global bioenergy potential from high-lignin agricultural residue.

    PubMed

    Mendu, Venugopal; Shearin, Tom; Campbell, J Elliott; Stork, Jozsef; Jae, Jungho; Crocker, Mark; Huber, George; DeBolt, Seth

    2012-03-01

    Almost one-quarter of the world's population has basic energy needs that are not being met. Efforts to increase renewable energy resources in developing countries where per capita energy availability is low are needed. Herein, we examine integrated dual use farming for sustained food security and agro-bioenergy development. Many nonedible crop residues are used for animal feed or reincorporated into the soil to maintain fertility. By contrast, drupe endocarp biomass represents a high-lignin feedstock that is a waste stream from food crops, such as coconut (Cocos nucifera) shell, which is nonedible, not of use for livestock feed, and not reintegrated into soil in an agricultural setting. Because of high-lignin content, endocarp biomass has optimal energy-to-weight returns, applicable to small-scale gasification for bioelectricity. Using spatial datasets for 12 principal drupe commodity groups that have notable endocarp byproduct, we examine both their potential energy contribution by decentralized gasification and relationship to regions of energy poverty. Globally, between 24 million and 31 million tons of drupe endocarp biomass is available per year, primarily driven by coconut production. Endocarp biomass used in small-scale decentralized gasification systems (15-40% efficiency) could contribute to the total energy requirement of several countries, the highest being Sri Lanka (8-30%) followed by Philippines (7-25%), Indonesia (4-13%), and India (1-3%). While representing a modest gain in global energy resources, mitigating energy poverty via decentralized renewable energy sources is proposed for rural communities in developing countries, where the greatest disparity between societal allowances exist. PMID:22355123

  2. Global bioenergy potential from high-lignin agricultural residue

    PubMed Central

    Mendu, Venugopal; Shearin, Tom; Campbell, J. Elliott; Stork, Jozsef; Jae, Jungho; Crocker, Mark; Huber, George; DeBolt, Seth

    2012-01-01

    Almost one-quarter of the world's population has basic energy needs that are not being met. Efforts to increase renewable energy resources in developing countries where per capita energy availability is low are needed. Herein, we examine integrated dual use farming for sustained food security and agro-bioenergy development. Many nonedible crop residues are used for animal feed or reincorporated into the soil to maintain fertility. By contrast, drupe endocarp biomass represents a high-lignin feedstock that is a waste stream from food crops, such as coconut (Cocos nucifera) shell, which is nonedible, not of use for livestock feed, and not reintegrated into soil in an agricultural setting. Because of high-lignin content, endocarp biomass has optimal energy-to-weight returns, applicable to small-scale gasification for bioelectricity. Using spatial datasets for 12 principal drupe commodity groups that have notable endocarp byproduct, we examine both their potential energy contribution by decentralized gasification and relationship to regions of energy poverty. Globally, between 24 million and 31 million tons of drupe endocarp biomass is available per year, primarily driven by coconut production. Endocarp biomass used in small-scale decentralized gasification systems (15–40% efficiency) could contribute to the total energy requirement of several countries, the highest being Sri Lanka (8–30%) followed by Philippines (7–25%), Indonesia (4–13%), and India (1–3%). While representing a modest gain in global energy resources, mitigating energy poverty via decentralized renewable energy sources is proposed for rural communities in developing countries, where the greatest disparity between societal allowances exist. PMID:22355123

  3. Ablation-induced explosion of metal using a high-power Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Yoh, Jack J.; Lee, Hyunhee; Choi, Jihee; Lee, Kyung-cheol; Kim, Ki-hong

    2008-02-01

    The interaction of a high-power pulsed-laser beam with metal targets in air from a 1.06 μm, 5 ns, 3 J/pulse, Nd:YAG pulsed laser is investigated together with hydrodynamic theories of laser-supported blast wave and multimaterial reactive Euler equations. The high-speed blast wave generated by the laser ablation of metal reaches a maximum velocity of several thousand meters per second. The apparently similar flow conditions to those of reactive shock wave allow one to apply the equations of motion for energetic materials and to understand the explosive behavior of metal vaporization upon laser ablation. The characteristic time at which the planar to spherical wave transition occurs is investigated at low (20 mJ/pulse) to high (200 mJ/pulse) beam intensities. The flow structure behind the leading shock wave during the early planar shock state is confirmed by the high-resolution multimaterial hydrocode originally developed for shock compression of condensed matter. A repeatable lab-scale blast wave experiment is conducted at various energy levels with three different ablative targets, and both theoretical and computational analyses are used to verify the flow structures behind the leading shock front that remains spherically symmetric until all the momentum transferred from the absorbed intensity dissipates into open air a few microseconds later.

  4. High Order Entropy-Constrained Residual VQ for Lossless Compression of Images

    NASA Technical Reports Server (NTRS)

    Kossentini, Faouzi; Smith, Mark J. T.; Scales, Allen

    1995-01-01

    High order entropy coding is a powerful technique for exploiting high order statistical dependencies. However, the exponentially high complexity associated with such a method often discourages its use. In this paper, an entropy-constrained residual vector quantization method is proposed for lossless compression of images. The method consists of first quantizing the input image using a high order entropy-constrained residual vector quantizer and then coding the residual image using a first order entropy coder. The distortion measure used in the entropy-constrained optimization is essentially the first order entropy of the residual image. Experimental results show very competitive performance.

  5. Fabrication of Optical Fiber Mechanical Shock Sensors for the Los Alamos HERT (High Explosive Radio Telemetry) Project

    SciTech Connect

    P. E. Klingsporn

    2005-11-14

    This document lists the requirements for the fiber optic mechanical shock sensor for the Los Alamos HERT (High Explosive Radio Telemetry) project and provides detailed process steps for fabricating, testing, and assembling the fiber shock sensors for delivery to Los Alamos.

  6. A highly efficient fluorescent sensor of explosive peroxide vapor via ZnO nanorod array catalyzed deboronation of pyrenyl borate.

    PubMed

    He, Chao; Zhu, Defeng; He, Qingguo; Shi, Liqi; Fu, Yanyan; Wen, Dan; Cao, Huimin; Cheng, Jiangong

    2012-06-11

    A new strategy capable of detecting explosive peroxide vapor via deboronation reaction induced fluorescence quenching has been developed. Using ordered assembly arrays of ZnO nanorods as catalyzing substrates, the deboronation reaction was 42 times faster than that on quartz substrates, which resulted in a very fast response and high sensitivity. PMID:22552712

  7. Demonstration of submersible high-throughput microfluidic immunosensors for underwater explosives detection.

    PubMed

    Adams, André A; Charles, Paul T; Deschamps, Jeffrey R; Kusterbeck, Anne W

    2011-11-15

    Significant security threats posed by highly energetic nitroaromatic compounds in aquatic environments and the demilitarization and pending cleanup of areas previously used for munitions manufacture and storage represent a challenge for less expensive, faster, and more sensitive systems capable of analyzing groundwater and seawater samples for trace levels of explosive materials. Presented here is an inexpensive high throughput microfluidic immunosensor (HTMI) platform intended for the rapid, highly selective quantitation of nitroaromatic compounds in the field. Immunoaffinity and fluorescence detection schemes were implemented in tandem on a novel microfluidic device containing 39 parallel microchannels that were 500 μm tall, 250 μm wide, and 2.54 cm long with covalently tethered antibodies that was engineered for high-throughput high-volume sample processing. The devices were produced via a combination of high precision micromilling and hot embossing. Mass transfer limitations were found in conventional microsystems and were minimized due to higher surface area to volume ratios that exceeded those possessed by conventional microdevices and capillaries. Until now, these assays were limited to maximum total volume flow rates of ~1 mL/min due in part to kinetics and high head pressures of single microchannels. In the design demonstrated here, highly parallelized microchannels afforded up to a 100-fold increase in total volume flow rate while maintaining favorable kinetic constraints for efficient antigen-antibody interaction. The assay employed total volume throughput of up to 6 mL/min while yielding signal-to-noise ratios of >15 in all cases. In addition to samples being processed up to 60 times faster than in conventional displacement-based immunoassays, the current system was capable of quantitating 0.01 ng/mL TNT samples without implementing offline preconcentration, thereby, demonstrating the ability to improve sensitivity by as much as 2 orders of magnitude

  8. Local fluctuation control of papain by changing a highly fluctuating residue

    NASA Astrophysics Data System (ADS)

    Nishiyama, Katsuhiko

    2013-01-01

    To control the local fluctuation of the amino acid residues of papain, ARG59, a highly fluctuating residue in papain, has been changed to GLY. We investigated the binding properties of 2-10GLY (peptides with between 2 and 10 glycine residues) to the modified papain structure via molecular dynamics and docking simulations. The change of the ARG59 residue to GLY alters the binding sites for some peptides, and changed its substrate specificity. Furthermore, the modification alters the binding stability of some peptides. Thus, control of the local fluctuations of residues in proteins has the potential to alter the protein's function.

  9. A study of phase explosion of metal using high power Nd:YAG laser ablation

    SciTech Connect

    Yoh, Jack J.; Lee, H. H.; Choi, J. H.; Lee, K. C.; Kim, K. H.

    2007-12-12

    The interaction of high-power pulsed-laser beam with metal targets in air from 1.06 {mu}m, 5 ns, 3 J/pulse max, Nd:YAG pulsed laser is investigated together with hydrodynamic theories of laser-supported detonation (LSD) wave and multi-material reactive Euler equations. The high speed blast wave generated by the laser ablation of metal reaches maximum velocity of several thousand meters per second. The apparently similar flow conditions to those of reactive shock wave allow one to apply the equations of motion for energetic materials and to understand the explosive behavior of metal vaporization upon laser ablation. The characteristic time at which planar to spherical wave transition occurs is confirmed at low (20 mJ/pulse) to higher (200 mJ/pulse) beam intensities. The flow structure behind the leading shock wave during the early planar shock state is confirmed by the high-resolution multi-material hydrocode originally developed for shock compression of condensed matter.

  10. a Study of Phase Explosion of Metal Using High Power Nd:YAG Laser Ablation

    NASA Astrophysics Data System (ADS)

    Yoh, Jack J.; Lee, H. H.; Choi, J. H.; Lee, K. C.; Kim, K. H.

    2007-12-01

    The interaction of high-power pulsed-laser beam with metal targets in air from 1.06 μm, 5 ns, 3 J/pulse max, Nd:YAG pulsed laser is investigated together with hydrodynamic theories of laser-supported detonation (LSD) wave and multi-material reactive Euler equations. The high speed blast wave generated by the laser ablation of metal reaches maximum velocity of several thousand meters per second. The apparently similar flow conditions to those of reactive shock wave allow one to apply the equations of motion for energetic materials and to understand the explosive behavior of metal vaporization upon laser ablation. The characteristic time at which planar to spherical wave transition occurs is confirmed at low (20 mJ/pulse) to higher (200 mJ/pulse) beam intensities. The flow structure behind the leading shock wave during the early planar shock state is confirmed by the high-resolution multi-material hydrocode originally developed for shock compression of condensed matter.

  11. Pressure wave measurements from thermal cook-off of an HMX based high explosive

    SciTech Connect

    Forbes, J W; Tarver, C M; Urtiew, P A; Garcia, F; Greenwood, D W; Vandersall, K S

    2000-10-10

    A better understanding of thermal cook-off is important for safe handling and storing explosive devices. A number of safety issues exist about what occurs when a cased explosive thermally cooks off. For example, violence of the events as a function of confinement are important for predictions of collateral damage. This paper demonstrates how adjacent materials can be gauged to measure the resulting pressure wave and how this wave propagates in this adjacent material. The output pulse from the thermal cook-off explosive containing fixture is of obvious interest for assessing many scenarios.

  12. Pressure Wave Measurements from Thermal Cook-Off of an HMX Based High Explosive PBX 9501

    SciTech Connect

    Garcia, F; Forbes, J W; Tarver, C M; Urtiew, P A; Greenwood, D W; Vandersall, K S

    2001-05-31

    A better understanding of thermal cook-off is important for safe handling and storing explosive devices. A number of safety issues exist about what occurs when a cased explosive thermally cooks off. For example, violence of the events as a function of confinement are important for predictions of collateral damage. This paper demonstrates how adjacent materials can be gauged to measure the resulting pressure wave and how this wave propagates in this adjacent material. The output pulse from the thermal cook-off explosive containing fixture is of obvious interest for assessing many scenarios.

  13. Quantum chemical studies on three novel 1,2,4-triazole N-oxides as potential insensitive high explosives.

    PubMed

    Wu, Qiong; Zhu, Weihua; Xiao, Heming

    2014-09-01

    Three novel explosives were designed by introducing N-oxides into 1,2,4-triazole: 1-amino-3,5-dinitro-1,2,4-triazole-2 N-oxide (ADT2NO), 1-amino-2,5-dinitro-1,2,4-triazole-3 N-oxide (ADT3NO), and 1-amino-3,5-dinitro-1,2,4-triazole-4 N-oxide (ADT4NO). Their detonation performance and sensitivity were estimated by using density functional theory and compared with some famous explosives like 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) and 1-methyl-2,4,6-trinitrobenzene (TNT). All three designed molecules are more powerful than HMX and less sensitive than TNT, indicating that ADT2NO, ADT3NO, and ADT4NO have high detonation performance as HMX and low sensitivity as TNT, making them being very valuable and may be considered as the potential candidates of insensitive high explosives. Properly introducing N-oxides into the energetic triazole derivatives can generate some superior energetic compounds with both high explosive performance and reduced sensitivity. PMID:25213112

  14. Non-detonable and non-explosive explosive simulators

    DOEpatents

    Simpson, Randall L.; Pruneda, Cesar O.

    1997-01-01

    A simulator which is chemically equivalent to an explosive, but is not detonable or explodable. The simulator is a combination of an explosive material with an inert material, either in a matrix or as a coating, where the explosive has a high surface ratio but small volume ratio. The simulator has particular use in the training of explosives detecting dogs, calibrating analytical instruments which are sensitive to either vapor or elemental composition, or other applications where the hazards associated with explosives is undesirable but where chemical and/or elemental equivalence is required. The explosive simulants may be fabricated by different techniques. A first method involves the use of standard slurry coatings to produce a material with a very high binder to explosive ratio without masking the explosive vapor, and a second method involves coating inert substrates with thin layers of explosive.

  15. Non-detonable and non-explosive explosive simulators

    DOEpatents

    Simpson, R.L.; Pruneda, C.O.

    1997-07-15

    A simulator which is chemically equivalent to an explosive, but is not detonable or explodable is disclosed. The simulator is a combination of an explosive material with an inert material, either in a matrix or as a coating, where the explosive has a high surface ratio but small volume ratio. The simulator has particular use in the training of explosives detecting dogs, calibrating analytical instruments which are sensitive to either vapor or elemental composition, or other applications where the hazards associated with explosives is undesirable but where chemical and/or elemental equivalence is required. The explosive simulants may be fabricated by different techniques. A first method involves the use of standard slurry coatings to produce a material with a very high binder to explosive ratio without masking the explosive vapor, and a second method involves coating inert substrates with thin layers of explosive. 11 figs.

  16. Automated High-Speed Video Detection of Small-Scale Explosives Testing

    NASA Astrophysics Data System (ADS)

    Ford, Robert; Guymon, Clint

    2013-06-01

    Small-scale explosives sensitivity test data is used to evaluate hazards of processing, handling, transportation, and storage of energetic materials. Accurate test data is critical to implementation of engineering and administrative controls for personnel safety and asset protection. Operator mischaracterization of reactions during testing contributes to either excessive or inadequate safety protocols. Use of equipment and associated algorithms to aid the operator in reaction determination can significantly reduce operator error. Safety Management Services, Inc. has developed an algorithm to evaluate high-speed video images of sparks from an ESD (Electrostatic Discharge) machine to automatically determine whether or not a reaction has taken place. The algorithm with the high-speed camera is termed GoDetect (patent pending). An operator assisted version for friction and impact testing has also been developed where software is used to quickly process and store video of sensitivity testing. We have used this method for sensitivity testing with multiple pieces of equipment. We present the fundamentals of GoDetect and compare it to other methods used for reaction detection.

  17. Accidental explosions

    SciTech Connect

    Medard, L.A.

    1989-01-01

    This book presents a survey of accidental explosions, their nature and their causes. It covers the physical and chemical conditions governing accidental explosions, whether in the gas phase, or in the liquid or solid state. The theoretical background of the kinetics and thermochemistry of explosions is outlined, followed by a detailed study of the explosion and detonation properties of both gas and condensed explosives. The author surveys a wide variety of substances in daily use in industry which can give rise to accidental explosions. Their properties and hazards are spelt out in detail, the discussion drawing on a long history of sometimes catastrophic accidents. Includes case studies, tables of physical and chemical data.

  18. Novel CE-MS technique for detection of high explosives using perfluorooctanoic acid as a MEKC and mass spectrometric complexation reagent.

    PubMed

    Brensinger, Karen; Rollman, Christopher; Copper, Christine; Genzman, Ashton; Rine, Jacqueline; Lurie, Ira; Moini, Mehdi

    2016-01-01

    To address the need for the forensic analysis of high explosives, a novel capillary electrophoresis mass spectrometry (CE-MS) technique has been developed for high resolution, sensitivity, and mass accuracy detection of these compounds. The technique uses perfluorooctanoic acid (PFOA) as both a micellar electrokinetic chromatography (MEKC) reagent for separation of neutral explosives and as the complexation reagent for mass spectrometric detection of PFOA-explosive complexes in the negative ion mode. High explosives that formed complexes with PFOA included RDX, HMX, tetryl, and PETN. Some nitroaromatics were detected as molecular ions. Detection limits in the high parts per billion range and linear calibration responses over two orders of magnitude were obtained. For proof of concept, the technique was applied to the quantitative analysis of high explosives in sand samples. PMID:26666592

  19. Implementation of algorithms to discriminate chemical/biological airbursts from high explosive airbursts utilizing acoustic signatures

    NASA Astrophysics Data System (ADS)

    Hohil, Myron E.; Desai, Sachi; Morcos, Amir

    2006-05-01

    The Army is currently developing acoustic sensor systems that will provide extended range surveillance, detection, and identification for force protection and tactical security. A network of such sensors remotely deployed in conjunction with a central processing node (or gateway) will provide early warning and assessment of enemy threats, near real-time situational awareness to commanders, and may reduce potential hazards to the soldier. In contrast, the current detection of chemical/biological (CB) agents expelled into a battlefield environment is limited to the response of chemical sensors that must be located within close proximity to the CB agent. Since chemical sensors detect hazardous agents through contact, the sensor range to an airburst is the key-limiting factor in identifying a potential CB weapon attack. The associated sensor reporting latencies must be minimized to give sufficient preparation time to field commanders, who must assess if an attack is about to occur, has occurred, or if occurred, the type of agent that soldiers might be exposed to. The long-range propagation of acoustic blast waves from heavy artillery blasts, which are typical in a battlefield environment, introduces a feature for using acoustics and other sensor suite technologies for the early detection and identification of CB threats. Employing disparate sensor technologies implies that warning of a potential CB attack can be provided to the solider more rapidly and from a safer distance when compared to current conventional methods. Distinct characteristics arise within the different airburst signatures because High Explosive (HE) warheads emphasize concussive and shrapnel effects, while chemical/biological warheads are designed to disperse their contents over immense areas, therefore utilizing a slower burning, less intensive explosion to mix and distribute their contents. Highly reliable discrimination (100%) has been demonstrated at the Portable Area Warning Surveillance System

  20. Implementation of algorithms to discriminate between chemical/biological airbursts and high explosive airbursts

    NASA Astrophysics Data System (ADS)

    Hohil, Myron E.; Desai, Sachi; Morcos, Amir

    2006-09-01

    The Army is currently developing acoustic sensor systems that will provide extended range surveillance, detection, and identification for force protection and tactical security. A network of such sensors remotely deployed in conjunction with a central processing node (or gateway) will provide early warning and assessment of enemy threats, near real-time situational awareness to commanders, and may reduce potential hazards to the soldier. In contrast, the current detection of chemical/biological (CB) agents expelled into a battlefield environment is limited to the response of chemical sensors that must be located within close proximity to the CB agent. Since chemical sensors detect hazardous agents through contact, the sensor range to an airburst is the key-limiting factor in identifying a potential CB weapon attack. The associated sensor reporting latencies must be minimized to give sufficient preparation time to field commanders, who must assess if an attack is about to occur, has occurred, or if occurred, the type of agent that soldiers might be exposed to. The long-range propagation of acoustic blast waves from heavy artillery blasts, which are typical in a battlefield environment, introduces a feature for using acoustics and other sensor suite technologies for the early detection and identification of CB threats. Employing disparate sensor technologies implies that warning of a potential CB attack can be provided to the solider more rapidly and from a safer distance when compared to current conventional methods. Distinct characteristics arise within the different airburst signatures because High Explosive (HE) warheads emphasize concussive and shrapnel effects, while chemical/biological warheads are designed to disperse their contents over immense areas, therefore utilizing a slower burning, less intensive explosion to mix and distribute their contents. Highly reliable discrimination (100%) has been demonstrated at the Portable Area Warning Surveillance System

  1. Extension and Explosivity during an Eccentric Era of the Early Oregon High Cascades

    NASA Astrophysics Data System (ADS)

    Pitcher, B. W.; Kent, A. J.; Grunder, A.; Duncan, R. A.; Eungard, D. W.

    2015-12-01

    One of the most profound changes that the Cascade arc experienced since its inception ~40 Ma, was an eastward shift in volcanic activity starting at ~7.5 Ma, which initiated the modern High Cascades. The infant stages of this arc are exceptionally well preserved within the Deschutes Fm. (~7.4 - 4.0 Ma) of Central Oregon. In stark contrast to the effusive andesitic eruptions that dominated ancestral Cascade volcanism for the preceding 10 million years, the Deschutes Fm. contains over 120 (uncorrelated) tephra fall units and 130 ignimbrite units, indicating an unusually explosive period of volcanism. Conservative estimates of the cumulative volume for 14 regionally extensive ignimbrites is greater than 80 km3. Furthermore, 40Ar-39Ar dating of plagioclase from 7 ignimbrites indicate that this large volume was erupted in less than 1 million years (6.24 ±0.07 to 5.44 ±0.04 Ma). Glass compositions of pumice (n=718) range from 54 to 76 wt. % SiO2. Most ignimbrites contain multiple pumice populations, including banded pumice, which can span nearly 20 wt. % SiO2, indicating involvement of multiple magma types. Two ignimbrites have a compositional gap between 62 and 68 wt. % SiO2, possibly suggesting mingling of a mafic magma with a silicic one derived from partial crustal melting. Trace element (e.g. Nb, Ce, Th) compositions of rhyolitic pumice differ between northern- and southern-sourced ignimbrites, which may be indicative of disparate crustal sources of partial melts (i.e. Siletzia in the North). In addition, Deschutes Fm. rocks are enriched in FeO* and Zr/Sr compared to Quaternary Cascades, and are more similar to High Lava Plains. These trends and the absence of amphibole within the formation suggests hotter and drier magmatic conditions. We suggest that regional extension contributed to increased basaltic flux, leading to anatexis of previously un-melted crust beneath the new arc axis, thereby producing large volumes of silicic magma during this short explosive

  2. High explosive simulations of supernovae and the supernova shell fragmentation model of solar system formation

    SciTech Connect

    Brown, W.K.

    1987-09-01

    Comparison of photographs of explosive experiments to the Casseopeia A supernova remnant reveals a striking similarity. The similarity could indicate the presence of a relatively cool, underlying shell in the Casseopeia A remnant. As this shell expands and fragments, the observable features are produced by hot gases squirting through the cracks - as in explosive experiments. The existence of such underlying shells in supernova remnants supports the author's model of solar system formation.

  3. Study of Explosive Electron Emission from a Pin Cathode Using High Resolution Point-Projection X-Ray Radiography

    NASA Astrophysics Data System (ADS)

    Pikuz, S. A.; Shelkovenko, T. A.; Hammer, D. A.; Parkevich, E. V.; Tilikin, I. N.; Mingaleev, A. R.; Agafonov, A. V.

    2015-11-01

    Most studies of Explosive Electron Emission (EEE) are based on the idea of cathode flares developing after explosion of metal whiskers (micron scale pins) on the cathode surface. The physical state of the pin material, the spatial structure of the explosion and its origin are still a matter of conjecture. In this work we used high-resolution point projection x-ray radiography to observe micron scale pin explosion in a high-current diode. Pin cathodes made from 10-25 micron Cu or Mo wires were placed in gaps in return current circuits of hybrid X-pinches on the XP and BIN pulsers. Pin lengths were varied over a range 1-4 mm and pin-anode gaps within 0.05-3 mm. The diode current and voltage were measured. In experiments with small pin-anode gap (0.1 - 1 mm) development of an expanded dense core of the pin was observed except the pin tip with length 100-200 microns indicating significant energy deposition in the wire material. In experiments with bigger gaps there was no visible wire core expansion within the spatial resolution of the experimental technique. Work at Cornell was supported by the National Nuclear Security Administration Stewardship Sciences Academic Programs under Department of Energy Cooperative Agreement No. DE-NA0001836 and at the Lebedev Institute by the RSF grant 142200273.

  4. Big Explosives Experimental Facility - BEEF

    SciTech Connect

    2014-10-31

    The Big Explosives Experimental Facility or BEEF is a ten acre fenced high explosive testing facility that provides data to support stockpile stewardship and other national security programs. At BEEF conventional high explosives experiments are safely conducted providing sophisticated diagnostics such as high speed optics and x-ray radiography.

  5. Big Explosives Experimental Facility - BEEF

    ScienceCinema

    None

    2015-01-07

    The Big Explosives Experimental Facility or BEEF is a ten acre fenced high explosive testing facility that provides data to support stockpile stewardship and other national security programs. At BEEF conventional high explosives experiments are safely conducted providing sophisticated diagnostics such as high speed optics and x-ray radiography.

  6. An X-band high-impedance relativistic klystron amplifier with an annular explosive cathode

    NASA Astrophysics Data System (ADS)

    Zhu, Danni; Zhang, Jun; Zhong, Huihuang; Qi, Zumin

    2015-11-01

    The feasibility of employing an annular beam instead of a solid one in the X-band high-impedance relativistic klystron amplifier (RKA) is investigated in theory and simulation. Small-signal theory analysis indicates that the optimum bunching distance, fundamental current modulation depth, beam-coupling coefficient, and beam-loaded quality factor of annular beams are all larger than the corresponding parameters of solid beams at the same beam voltage and current. An annular beam RKA and a solid beam RKA with almost the same geometric parameters are compared in particle-in-cell simulation. Output microwave power of 100 MW, gain of 50 dB, and power conversion efficiency of 42% are obtained in an annular beam RKA. The annular beam needs a 15% lower uniform guiding magnetic field than the solid beam. Our investigations demonstrate that we are able to use a simple annular explosive cathode immersed in a lower uniform magnetic field instead of a solid thermionic cathode in a complicated partially shielding magnetic field for designing high-impedance RKA, which avoids high temperature requirement, complicated electron-optical system, large area convergence, high current density, and emission uniformity for the solid beam. An equivalent method for the annular beam and the solid beam on bunching features is proposed and agrees with the simulation. The annular beam has the primary advantages over the solid beam that it can employ the immersing uniform magnetic field avoiding the complicated shielding magnetic field system and needs a lower optimum guiding field due to the smaller space charge effect.

  7. An X-band high-impedance relativistic klystron amplifier with an annular explosive cathode

    SciTech Connect

    Zhu, Danni; Zhang, Jun Zhong, Huihuang; Qi, Zumin

    2015-11-15

    The feasibility of employing an annular beam instead of a solid one in the X-band high-impedance relativistic klystron amplifier (RKA) is investigated in theory and simulation. Small-signal theory analysis indicates that the optimum bunching distance, fundamental current modulation depth, beam-coupling coefficient, and beam-loaded quality factor of annular beams are all larger than the corresponding parameters of solid beams at the same beam voltage and current. An annular beam RKA and a solid beam RKA with almost the same geometric parameters are compared in particle-in-cell simulation. Output microwave power of 100 MW, gain of 50 dB, and power conversion efficiency of 42% are obtained in an annular beam RKA. The annular beam needs a 15% lower uniform guiding magnetic field than the solid beam. Our investigations demonstrate that we are able to use a simple annular explosive cathode immersed in a lower uniform magnetic field instead of a solid thermionic cathode in a complicated partially shielding magnetic field for designing high-impedance RKA, which avoids high temperature requirement, complicated electron-optical system, large area convergence, high current density, and emission uniformity for the solid beam. An equivalent method for the annular beam and the solid beam on bunching features is proposed and agrees with the simulation. The annular beam has the primary advantages over the solid beam that it can employ the immersing uniform magnetic field avoiding the complicated shielding magnetic field system and needs a lower optimum guiding field due to the smaller space charge effect.

  8. Highly sensitive gas-phase explosive detection by luminescent microporous polymer networks.

    PubMed

    Räupke, André; Palma-Cando, Alex; Shkura, Eugen; Teckhausen, Peter; Polywka, Andreas; Görrn, Patrick; Scherf, Ullrich; Riedl, Thomas

    2016-01-01

    We propose microporous networks (MPNs) of a light emitting spiro-carbazole based polymer (PSpCz) as luminescent sensor for nitro-aromatic compounds. The MPNs used in this study can be easily synthesized on arbitrarily sized/shaped substrates by simple and low-cost electrochemical deposition. The resulting MPN afford an extremely high specific surface area of 1300 m(2)/g, more than three orders of magnitude higher than that of the thin films of the respective monomer. We demonstrate, that the luminescence of PSpCz is selectively quenched by nitro-aromatic analytes, e.g. nitrobenzene, 2,4-DNT and TNT. In striking contrast to a control sample based on non-porous spiro-carbazole, which does not show any luminescence quenching upon exposure to TNT at levels of 3 ppm and below, the microporous PSpCz shows a clearly detectable response even at TNT concentrations as low as 5 ppb, clearly demonstrating the advantage of microporous films as luminescent sensors for traces of explosive analytes. This level states the vapor pressure of TNT at room temperature. PMID:27373905

  9. Highly sensitive gas-phase explosive detection by luminescent microporous polymer networks

    NASA Astrophysics Data System (ADS)

    Räupke, André; Palma-Cando, Alex; Shkura, Eugen; Teckhausen, Peter; Polywka, Andreas; Görrn, Patrick; Scherf, Ullrich; Riedl, Thomas

    2016-07-01

    We propose microporous networks (MPNs) of a light emitting spiro-carbazole based polymer (PSpCz) as luminescent sensor for nitro-aromatic compounds. The MPNs used in this study can be easily synthesized on arbitrarily sized/shaped substrates by simple and low-cost electrochemical deposition. The resulting MPN afford an extremely high specific surface area of 1300 m2/g, more than three orders of magnitude higher than that of the thin films of the respective monomer. We demonstrate, that the luminescence of PSpCz is selectively quenched by nitro-aromatic analytes, e.g. nitrobenzene, 2,4-DNT and TNT. In striking contrast to a control sample based on non-porous spiro-carbazole, which does not show any luminescence quenching upon exposure to TNT at levels of 3 ppm and below, the microporous PSpCz shows a clearly detectable response even at TNT concentrations as low as 5 ppb, clearly demonstrating the advantage of microporous films as luminescent sensors for traces of explosive analytes. This level states the vapor pressure of TNT at room temperature.

  10. Low amplitude insult project: PBX 9501 high explosive violent reaction experiments

    SciTech Connect

    Idar, D.J.; Lucht, R.A.; Straight, J.W.; Scammon, R.J.; Browning, R.V.; Middleditch, J.; Dienes, J.K.; Skidmore, C.B.; Buntain, G.A.

    1998-12-31

    The Modified Steven test geometry has been used with several different target designs to investigate the mechanical loading behavior of PBX 9501 to a low velocity impact. A 2 kg. mild steel spigot projectile is launched via a new powder driven gun design, from {approximately} 20 to 105 m/s, at lightly confined, steel targets. Brief descriptions of the gun design and operation are given. The threshold velocity to reaction for various target designs, different PBX 9501 lots, and different high explosive (HE) thicknesses are reported and compared. Various diagnostics have been employed to evaluate the pressure profile and timing, and target strain behavior relative to projectile impact. The violence of reaction, as measured by both passive and active techniques, is reported relative to a steady state detonation in PBX 9501. Experimental results suggest slightly different ignition mechanisms dominate based on (HE) thickness, resulting in delayed reactions from {approximately} 0.2- to 2.8-ms after impact. Post-test analyses of the PBX 9501 are briefly summarized.

  11. Sensitivity effects of void density and arrangements in a REBO high explosive

    SciTech Connect

    Herring, Stuart Davis; Germann, Timothy C; Gronbech - Jensen, Niels

    2010-09-28

    The shock response of two-dimensional model, high explosive crystals with various arrangements of circular voids is explored. We simulate a piston impact using molecular dynamics simulations with a Reactive Empirical Bond Order (REBO) model potential for a sub-micron, sub-ns exothermic reaction in a diatomic molecular solid. In square lattices of voids all of one size, reducing that size or increasing the porosity while holding the other parameter fixed causes the hotspots to consume the material more quickly and detonation to occur sooner and at lower piston velocities. The early time behavior is seen to follow a very simple ignition and growth model. The hotspots are seen to collectively develop a broad pressure wave (a sonic, diffuse deflagration front) that, upon merging with the lead shock, transforms it into a detonation. The reaction yields produced by triangular lattices are not significantly different. With random void arrangements, the mean time to detonation is 15.5% larger than with the square lattice; the standard deviation of detonation delays is just 5.1%.

  12. Ecological surveys of the proposed high explosives wastewater treatment facility region

    SciTech Connect

    Haarmann, T.

    1995-07-01

    Los Alamos National Laboratory (LANL) proposes to improve its treatment of wastewater from high explosives (HE) research and development activities. The proposed project would focus on a concerted waste minimization effort to greatly reduce the amount of wastewater needing treatment. The result would be a 99% decrease in the HE wastewater volume, from the current level of 6,760,000 L/mo (1,786,000 gal./mo) to 41,200 L/mo (11,000 gal./mo). This reduction would entail closure of HE wastewater outfalls, affecting some wetland areas that depend on HE wastewater effluents. The outfalls also provide drinking water for many wildlife species. Terminating the flow of effluents at outfalls would represent an improvement in water quality in the LANL region but locally could have a negative effect on some wetlands and wildlife species. None of the affected species are protected by any state or federal endangered species laws. The purpose of this report is to briefly discuss the different biological studies that have been done in the region of the project area. This report is written to give biological information and baseline data and the biota of the project area.

  13. New, high-efficiency ion trap mobility detection system for narcotics and explosives

    NASA Astrophysics Data System (ADS)

    McGann, William J.; Bradley, V.; Borsody, A.; Lepine, S.

    1994-10-01

    A new patented Ion Trap Mobility Spectrometer (ITMS) design is presented. Conventional IMS designs typically operate below 0.1% efficiency. This is due primarily to electric field driven, sample ion discharge on a shutter grid. Since 99.9% of the sample ions generated in the reaction region are lost in this discharge process, the sensitivity of conventional systems is limited. The new design provides greater detection efficiency than conventional designs through the use of an `ion trap' concept. The paper describes the plasma and sample ion dynamics in the reaction region of the new detector and discusses the advantages of utilizing a `field-free' space to generate sample ions with high efficiency. Fast electronic switching is described which is used to perturb the field-free space and pulse the sample ions into the drift region for separation and subsequent detection using pseudo real-time software for analysis and display of the data. Many applications for this new detector are now being considered including the detection of narcotics and explosives. Preliminary ion spectra, reduced mobility data and sensitivity data are presented for fifteen narcotics, including cocaine, THC and LSD are reported.

  14. Transient Formation of Super-Explosives under High Pressure for Fast Ignition.

    NASA Astrophysics Data System (ADS)

    Winterberg, Friedwardt

    2007-11-01

    Dense matter, if put under high pressure, can undergo a transformation from an atomic to a molecular configuration, where the electron orbits go into lower energy levels. If the rise in pressure is very sudden, for example by a strong shock wave, the electrons change their orbits rapidly under the emission of photons, which for more than 100 megabar can reach keV energies. With the opacity of dense matter going in proportion to the square of the density, the photons can be efficiently released from the surface of the compressed matter by a rarefaction wave. The thusly produced X-ray photons can be used for the fast ignition of a thermonuclear target. Since as for thermite, the conjectured super-explosives are likely to come from the reaction between two different atoms, they should be made from a mixture of nanoparticles. The proposed mechanism may be also responsible for the large keV X-ray bursts in exploding wire arrays, which can not be explained by a simple kinetic into thermal energy conversion model.

  15. Highly sensitive gas-phase explosive detection by luminescent microporous polymer networks

    PubMed Central

    Räupke, André; Palma-Cando, Alex; Shkura, Eugen; Teckhausen, Peter; Polywka, Andreas; Görrn, Patrick; Scherf, Ullrich; Riedl, Thomas

    2016-01-01

    We propose microporous networks (MPNs) of a light emitting spiro-carbazole based polymer (PSpCz) as luminescent sensor for nitro-aromatic compounds. The MPNs used in this study can be easily synthesized on arbitrarily sized/shaped substrates by simple and low-cost electrochemical deposition. The resulting MPN afford an extremely high specific surface area of 1300 m2/g, more than three orders of magnitude higher than that of the thin films of the respective monomer. We demonstrate, that the luminescence of PSpCz is selectively quenched by nitro-aromatic analytes, e.g. nitrobenzene, 2,4-DNT and TNT. In striking contrast to a control sample based on non-porous spiro-carbazole, which does not show any luminescence quenching upon exposure to TNT at levels of 3 ppm and below, the microporous PSpCz shows a clearly detectable response even at TNT concentrations as low as 5 ppb, clearly demonstrating the advantage of microporous films as luminescent sensors for traces of explosive analytes. This level states the vapor pressure of TNT at room temperature. PMID:27373905

  16. Critical velocities for deflagration and detonation triggered by voids in a REBO high explosive

    SciTech Connect

    Herring, Stuart Davis; Germann, Timothy C; Jensen, Niels G

    2010-01-01

    The effects of circular voids on the shock sensitivity of a two-dimensional model high explosive crystal are considered. We simulate a piston impact using molecular dynamics simulations with a Reactive Empirical Bond Order (REBO) model potential for a sub-micron, sub-ns exothermic reaction in a diatomic molecular solid. The probability of initiating chemical reactions is found to rise more suddenly with increasing piston velocity for larger voids that collapse more deterministically. A void with radius as small as 10 nm reduces the minimum initiating velocity by a factor of 4. The transition at larger velocities to detonation is studied in a micron-long sample with a single void (and its periodic images). The reaction yield during the shock traversal increases rapidly with velocity, then becomes a prompt, reliable detonation. A void of radius 2.5 nm reduces the critical velocity by 10% from the perfect crystal. A Pop plot of the time-to-detonation at higher velocities shows a characteristic pressure dependence.

  17. Computational Study of 3-D Hot-Spot Initiation in Shocked Insensitive High-Explosive

    NASA Astrophysics Data System (ADS)

    Najjar, F. M.; Howard, W. M.; Fried, L. E.

    2011-06-01

    High explosive shock sensitivity is controlled by a combination of mechanical response, thermal properties, and chemical properties. The interplay of these physical phenomena in realistic condensed energetic materials is currently lacking. A multiscale computational framework is developed investigating hot spot (void) ignition in a single crystal of an insensitive HE, TATB. Atomistic MD simulations are performed to provide the key chemical reactions and these reaction rates are used in 3-D multiphysics simulations. The multiphysics code, ALE3D, is linked to the chemistry software, Cheetah, and a three-way coupled approach is pursued including hydrodynamics, thermal and chemical analyses. A single spherical air bubble is embedded in the insensitive HE and its collapse due to shock initiation is evolved numerically in time; while the ignition processes due chemical reactions are studied. Our current predictions showcase several interesting features regarding hot spot dynamics including the formation of a ``secondary'' jet. Results obtained with hydro-thermo-chemical processes leading to ignition growth will be discussed for various pore sizes and different shock pressures. LLNL-ABS-471438. This work performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

  18. Damage & fracture of high-explosive mock subject to cyclic loading

    SciTech Connect

    Liu, Cheng; Rae, Philip J; Cady, Carl M; Lovato, Manuel L

    2011-01-11

    We use four-point bend specimen with a single shallow edge notch to study the fracture process in Mock 900-21, a PBX 9501 high explosive simulant mock. Subject to monotonic loading we determine quantitatively the threshold load for macroscopic crack initiation from the notch tip. The four-point bend specimen is then subject to cyclic loading in such a way that during the first cycle, the applied force approaches but does not exceed the threshold load determined from the monotonic loading test and in the subsequent cycles, the overall maximum deformation is maintained to be equal to that of the first cycle. It is expected and is also confirmed that no macroscopic damage and cracking occur during the first cycle. However, we observe that sizable macroscopic crack is generated and enlarged during the subsequent cycles, even though the applied force never exceeds the threshold load. Details of the process of damage fonnation, accumulation, and crack extension are presented and the mechanical mechanism responsible for such failure process is postulated and discussed.

  19. New high-efficiency ion trap mobility detection system for narcotics and explosives

    NASA Astrophysics Data System (ADS)

    McGann, William J.; Jenkins, Anthony; Ribiero, K.; Napoli, J.

    1994-03-01

    A new patented ion trap mobility spectrometer design is presented. Conventional IMS designs typically operate below 0.1% efficiency. This is due primarily to electrical-field-driven, sample ion discharge on a shutter grid. Since 99.9% of the sample ions generated in the reaction region are lost in this discharge process, the sensitivity of conventional systems is limited. The new design provides greater detection efficiency than conventional designs through the use of an `ion trap' concept. The paper describes the plasma and sample ion dynamics in the reaction region of the new detector and discusses the advantages of utilizing a `field-free' space to generate sample ions with high efficiency. Fast electronic switching is described which is used to perturb the field-free space and pulse the sample ions into the drift region for separation and subsequent detection using pseudo real-time software for analysis and display of the data. Many applications for this new detector are now being considered including the detection of narcotics and explosives. Preliminary ion spectra, reduced mobility data and sensitivity data are presented for fifteen narcotics, including cocaine, THC, and LSD are reported.

  20. Performance evaluation of diaminoazoxyfurazan (DAAF) as a booster material for insensitive high explosives using the onionskin test

    SciTech Connect

    Morris, John S; Francois, Elizabeth G; Hooks, Daniel E; Hill, Larry G; Harry, Herbert H

    2010-11-09

    Initiation of insensitive high explosive (IHE) formulations requires the use of a booster explosive in the initiation train. Booster material selection is crucial, as the initiation must reliably function across some spectrum of physical parameters. The interest in DAAF for this application stems from the fact that it possesses many traits of an IHE but is shock sensitive enough to serve as an explosive booster. A hemispherical wave breakout test, termed the onionskin test, is one of the methods used to evaluate the performance of a booster material. The wave breakout time-position history at the surface of a hemisphericallHE charge is recorded and the relative uniformity of the breakout can be quantitatively compared between booster materials. A series of onionskin tests were performed to investigate breakout and propagation diaminoazoxyfurazan (DAAF) at low temperatures to evaluate ignition and detonation spreading in comparison to other explosives commonly used in booster applications. Some wave perturbation was observed with the DAAF booster in the onionskin tests presented. The results of these tests will be presented and discussed.

  1. High-resolution optical signatures of fresh and aged explosives in the 420nm to 620nm illumination range

    NASA Astrophysics Data System (ADS)

    Lunsford, Robert; Grun, Jacob; Gump, Jared

    2012-06-01

    Optical signatures of fresh and aged explosives are measured and compared to determine whether there exist differences in the signatures that can be exploited for detection. The explosives examined are RDX, TNT, and HMX, which have been heated for two weeks at 75 degrees centigrade or irradiated for two weeks with a 15-Watt ultraviolet lamp (254nm). The optical signatures are obtained by illuminating the samples with a sequence of laser wavelengths between 420nm and 620nm in 10 nm steps and measuring the spectra of light scattered from the sample at each laser wavelength. The measurements are performed on the Naval Research Laboratory's SWOrRD instrument. SWOrRD is capable of illuminating a sample with laser wavelength between 210nm and 2000nm, in steps of 0.1nm, and measuring the spectrum of light scattered from the sample at each wavelength. SWOrRD's broad tuning range, high average power (1- 300mW), narrow line width (< 4cm-1), and rapid wavelength tunability enable these measurements. Results, based on more than 80 measurements - each at 21 sequential laser wavelengths, indicate that the variation in spectral line amplitude observed when altering laser illumination wavelength differs between fresh and aged explosives. Thus, an instrument for rapid and reagent-less differentiation between aged and fresh explosives, based on illumination with a few appropriately chosen laser wavelengths appears feasible.

  2. Highly selective and sensitive fluorescent paper sensor for nitroaromatic explosive detection.

    PubMed

    Ma, Yingxin; Li, Hao; Peng, Shan; Wang, Leyu

    2012-10-01

    Rapid, sensitive, and selective detection of explosives such as 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitrophenol (TNP), especially using a facile paper sensor, is in high demand for homeland security and public safety. Although many strategies have been successfully developed for the detection of TNT, it is not easy to differentiate the influence from TNP. Also, few methods were demonstrated for the selective detection of TNP. In this work, via a facile and versatile method, 8-hydroxyquinoline aluminum (Alq(3))-based bluish green fluorescent composite nanospheres were successfully synthesized through self-assembly under vigorous stirring and ultrasonic treatment. These polymer-coated nanocomposites are not only water-stable but also highly luminescent. Based on the dramatic and selective fluorescence quenching of the nanocomposites via adding TNP into the aqueous solution, a sensitive and robust platform was developed for visual detection of TNP in the mixture of nitroaromatics including TNT, 2,4-dinitrotoluene (DNT), and nitrobenzene (NB). Meanwhile, the fluorescence intensity is proportional to the concentration of TNP in the range of 0.05-7.0 μg/mL with the 3σ limit of detection of 32.3 ng/mL. By handwriting or finger printing with TNP solution as ink on the filter paper soaked with the fluorescent nanocomposites, the bluish green fluorescence was instantly and dramatically quenched and the dark patterns were left on the paper. Therefore, a convenient and rapid paper sensor for TNP-selective detection was fabricated. PMID:22946839

  3. Development of an air cleaning system for dissolving high explosives from nuclear warheads

    SciTech Connect

    Bergman, W.; Wilson, K.; Staggs, K.; Wapman, D.

    1997-08-01

    The Department of Energy (DOE) has a major effort underway in dismantling nuclear weapons. In support of this effort we have been developing a workstation for removing the high explosive (HE) from nuclear warheads using hot sprays of dimethyl sulfoxide (DMSO) solvent to dissolve the HE. An important component of the workstation is the air cleaning system that is used to contain DMSO aerosols and vapor and radioactive aerosols. The air cleaning system consists of a condenser to liquefy the hot DMSO vapor, a demister pad to remove most of the DMSO aerosols, a high efficiency particulate air (HEPA) filter to remove the remaining aerosols, an activated carbon filter to remove the DMSO vapor, and a final HEPA filter to meet the redundancy requirement for HEPA filters in radioactive applications. The demister pad is a 4{double_prime} thick mat of glass and steel fibers and was selected after conducting screening tests on promising candidates. We also conducted screening tests on various activated carbons and found that all had a similar performance. The carbon breakthrough curves were fitted to a modified Wheeler`s equation and gave excellent predictions for the effect of different flow rates. After all of the components were assembled, we ran a series of performance tests on the components and system to determine the particle capture efficiency as a function of size for dioctyl sebacate (DOS) and DMSO aerosols using laser particle counters and filter samples. The pad had an efficiency greater than 990% for 0.1 {mu}m DMSO particles. Test results on the prototype carbon filter showed only 70% efficiency, instead of the 99.9% in small scale laboratory tests. Thus further work will be required to develop the prototype carbon filter. 7 refs., 18 figs., 10 tabs.

  4. Hydrolysis of plutonium: Corrosion kinetics in DMSO solutions containing simulated high explosive and water

    SciTech Connect

    Haschke, J.M.; Pruner, R.E. II

    1995-01-01

    A sequence of experiments is described that address the compatibility of plutonium metal with dimethyl sulfoxide solvent and with solutions containing simulated HMX explosive and simulated explosive plus water. In the absence of water, reaction is slow and forms a thin adherent product layer on clean metal surfaces. Corrosion of oxide-coated plutonium is observed after 15 to 20 days in a solution containing 0.18 mass % (0.11 M) water. After corrosion initiates, the rate accelerates rapidly and attains a value of 0.13 mg Pu/cm{sup 2} h with a surface that is approximately one percent active. Dependence of the Pu + H{sub 2}O reaction on water concentration is evaluated using the data from literature sources. Hazards associated with the use of wet dimethyl sulfoxide as a solvent for removing explosives during weapon dismantlement are identified and a simple method for their mitigation is outlined.

  5. Explosively pumped laser light

    DOEpatents

    Piltch, Martin S.; Michelotti, Roy A.

    1991-01-01

    A single shot laser pumped by detonation of an explosive in a shell casing. The shock wave from detonation of the explosive causes a rare gas to luminesce. The high intensity light from the gas enters a lasing medium, which thereafter outputs a pulse of laser light to disable optical sensors and personnel.

  6. Explosives simulants: Preliminary report

    SciTech Connect

    Moody, G.L.; Pruneda, C.O.; Simpson, R.L.

    1992-03-04

    Two TNT high explosives simulants have been developed. Small scale testing has shown them to be insensitive to: impact, spark, friction, temperature, and shock. The materials have been scaled to 0.5 kg quantities and samples given to the Protective Services Department for field evaluation using explosives detecting canines.

  7. Explosively pumped laser light

    SciTech Connect

    Piltch, M.S.; Michelott, R.A.

    1991-09-24

    This patent describes a single shot laser pumped by detonation of an explosive in a shell casing. The shock wave from detonation of the explosive causes a rare gas to luminesce. The high intensity light from the gas enters a lasing medium, which thereafter outputs a pulse of laser light to disable optical sensors and personnel.

  8. Surrogate Modeling of High-Fidelity Fracture Simulations for Real-Time Residual Strength Predictions

    NASA Technical Reports Server (NTRS)

    Spear, Ashley D.; Priest, Amanda R.; Veilleux, Michael G.; Ingraffea, Anthony R.; Hochhalter, Jacob D.

    2011-01-01

    A surrogate model methodology is described for predicting in real time the residual strength of flight structures with discrete-source damage. Starting with design of experiment, an artificial neural network is developed that takes as input discrete-source damage parameters and outputs a prediction of the structural residual strength. Target residual strength values used to train the artificial neural network are derived from 3D finite element-based fracture simulations. A residual strength test of a metallic, integrally-stiffened panel is simulated to show that crack growth and residual strength are determined more accurately in discrete-source damage cases by using an elastic-plastic fracture framework rather than a linear-elastic fracture mechanics-based method. Improving accuracy of the residual strength training data would, in turn, improve accuracy of the surrogate model. When combined, the surrogate model methodology and high-fidelity fracture simulation framework provide useful tools for adaptive flight technology.

  9. High Speed Photographic Observation Of The Initiation Of Detonation In Explosives By Imploding Shock Waves

    NASA Astrophysics Data System (ADS)

    Austing, James L.; Tulis, Allen J.; Heberlein, David C.

    1984-01-01

    This paper is concerned with the use of a Beckman & Whitley Model 189 framing camera to observe the initiation of detonation in cylindrical explosive charges by the detonation of a concentric outside layer of sheet explosive initiated at one end. Experiments were con-ducted with nitromethane, which is a transparent liquid explosive, and aluminum-potassium perchlorate, which is a binary mixture of fuel and oxidizer powders. The use of the transparent explosive permitted viewing along the entire length of the charge axis, so that the time of the nitromethane initiation as a function of the position of the concentric sheet explosive detonation could be observed. In the case of the binary charge, the experiment involved the simultaneous viewing of both the side and the end of the charge by a judicious positioning of two front-surface mirrors. One of these was oriented at the end of the charge at an angle of 45° with respect to the charge axis. The second mirror, larger in size, viewed the entire system, and was destructed at 656 psec by an explosive backing charge to preclude the possibility of film rewrite. Framing rates for both experiments were approximately 250,000 frames/sec. The induction time to initiation of detonation in the nitromethane was measured to be about 20 psec. However, the induction time for the aluminum-potassium perchlorate charge was too long to be recorded by the Beckman and Whitley camera. For this and other pyrotechnic dharges, it was necessary to use a slower writing Fastax camera recording at a rate of 2000 frames/sec; the induction times for the pyrotechnic systems were in the neighborhood of 1 to 3 msec, which is two orders of magnitude longer than for the nitromethane.

  10. Numerical simulation of Composition B high explosive charge desensitization in gap test assembly after loading by precursor wave

    NASA Astrophysics Data System (ADS)

    Balagansky, I. A.; Stepanov, A. A.

    2016-03-01

    Results of numerical research into the desensitization of high explosive charges in water gap test-based experimental assemblies are presented. The experimental data are discussed, and the analysis using ANSYS AUTODYN 14.5 is provided. The desensitization phenomenon is well reproduced in numerical simulation using the JWL EOS and the Lee-Tarver kinetic equation for modeling of the initiation of heterogeneous high explosives with as well as without shock front waves. The analysis of the wave processes occurring during the initiation of the acceptor HE charge has been carried out. Peculiarities of the wave processes in the water gap test assemblies, which can influence the results of sensitivity measurement, have been studied. In particular, it has been established that precursor waves in the walls of the gap test assemblies can influence the detonation transmission distance.

  11. Reliable discrimination of high explosive and chemical/biological artillery using acoustic UGS

    NASA Astrophysics Data System (ADS)

    Hohil, Myron E.; Desai, Sachi

    2005-10-01

    discrimination between conventional and simulated chemical/biological artillery rounds using acoustic signals produced during detonation. Distinct characteristics arise within the different airburst signatures because high explosive warheads emphasize concussive and shrapnel effects, while chemical/biological warheads are designed to disperse their contents over large areas, therefore employing a slower burning, less intense explosive to mix and spread their contents. The ensuing blast waves are readily characterized by variations in the corresponding peak pressure and rise time of the blast, differences in the ratio of positive pressure amplitude to the negative amplitude, and variations in the overall duration of the resulting waveform. We show that, highly reliable discrimination (> 98%) between conventional and potentially chemical/biological artillery is achieved at ranges exceeding 3km. A feedforward neural network classifier, trained on a feature space derived from the distribution of wavelet coefficients found within different levels of the multiresolution decomposition yields.

  12. The Off-Site Plowshare and Vela Uniform Programs: Assessing Potential Environmental Liabilities through an Examination of Proposed Nuclear Projects,High Explosive Experiments, and High Explosive Construction Activities Volume 3 of 3

    SciTech Connect

    Beck Colleen M.,Edwards Susan R.,King Maureen L.

    2011-09-01

    This document presents the results of nearly six years (2002-2008) of historical research and field studies concerned with evaluating potential environmental liabilities associated with U.S. Atomic Energy Commission projects from the Plowshare and Vela Uniform Programs. The Plowshare Program's primary purpose was to develop peaceful uses for nuclear explosives. The Vela Uniform Program focused on improving the capability of detecting, monitoring and identifying underground nuclear detonations. As a result of the Project Chariot site restoration efforts in the early 1990s, there were concerns that there might be other project locations with potential environmental liabilities. The Desert Research Institute conducted archival research to identify projects, an analysis of project field activities, and completed field studies at locations where substantial fieldwork had been undertaken for the projects. Although the Plowshare and Vela Uniform nuclear projects are well known, the projects that are included in this research are relatively unknown. They are proposed nuclear projects that were not executed, proposed and executed high explosive experiments, and proposed and executed high explosive construction activities off the Nevada Test Site. The research identified 170 Plowshare and Vela Uniform off-site projects and many of these had little or no field activity associated with them. However, there were 27 projects that merited further investigation and field studies were conducted at 15 locations.

  13. The Off-Site Plowshare and Vela Uniform Programs: Assessing Potential Environmental Liabilities through an Examination of Proposed Nuclear Projects,High Explosive Experiments, and High Explosive Construction Activities Volume 1 of 3

    SciTech Connect

    Beck Colleen M,Edwards Susan R.,King Maureen L.

    2011-09-01

    This document presents the results of nearly six years (2002-2008) of historical research and field studies concerned with evaluating potential environmental liabilities associated with U.S. Atomic Energy Commission projects from the Plowshare and Vela Uniform Programs. The Plowshare Program's primary purpose was to develop peaceful uses for nuclear explosives. The Vela Uniform Program focused on improving the capability of detecting, monitoring and identifying underground nuclear detonations. As a result of the Project Chariot site restoration efforts in the early 1990s, there were concerns that there might be other project locations with potential environmental liabilities. The Desert Research Institute conducted archival research to identify projects, an analysis of project field activities, and completed field studies at locations where substantial fieldwork had been undertaken for the projects. Although the Plowshare and Vela Uniform nuclear projects are well known, the projects that are included in this research are relatively unknown. They are proposed nuclear projects that were not executed, proposed and executed high explosive experiments, and proposed and executed high explosive construction activities off the Nevada Test Site. The research identified 170 Plowshare and Vela Uniform off-site projects and many of these had little or no field activity associated with them. However, there were 27 projects that merited further investigation and field studies were conducted at 15 locations.

  14. The Off-Site Plowshare and Vela Uniform Programs: Assessing Potential Environmental Liabilities through an Examination of Proposed Nuclear Projects,High Explosive Experiments, and High Explosive Construction Activities Volume 2 of 3

    SciTech Connect

    Beck Colleen M.,Edwards Susan R.,King Maureen L.

    2011-09-01

    This document presents the results of nearly six years (2002-2008) of historical research and field studies concerned with evaluating potential environmental liabilities associated with U.S. Atomic Energy Commission projects from the Plowshare and Vela Uniform Programs. The Plowshare Program's primary purpose was to develop peaceful uses for nuclear explosives. The Vela Uniform Program focused on improving the capability of detecting, monitoring and identifying underground nuclear detonations. As a result of the Project Chariot site restoration efforts in the early 1990s, there were concerns that there might be other project locations with potential environmental liabilities. The Desert Research Institute conducted archival research to identify projects, an analysis of project field activities, and completed field studies at locations where substantial fieldwork had been undertaken for the projects. Although the Plowshare and Vela Uniform nuclear projects are well known, the projects that are included in this research are relatively unknown. They are proposed nuclear projects that were not executed, proposed and executed high explosive experiments, and proposed and executed high explosive construction activities off the Nevada Test Site. The research identified 170 Plowshare and Vela Uniform off-site projects and many of these had little or no field activity associated with them. However, there were 27 projects that merited further investigation and field studies were conducted at 15 locations.

  15. Shock-to-detonation transition of RDX and NTO based composite high explosives: experiments and modeling

    NASA Astrophysics Data System (ADS)

    Baudin, Gerard; Roudot, Marie; Genetier, Marc

    2013-06-01

    Composite HMX and NTO based high explosives (HE) are widely used in ammunitions. Designing modern warheads needs robust and reliable models to compute shock ignition and detonation propagation inside HE. Comparing to a pressed HE, a composite HE is not porous and the hot-spots are mainly located at the grain - binder interface leading to a different behavior during shock-to-detonation transition. An investigation of how shock-to-detonation transition occurs inside composite HE containing RDX and NTO is proposed in this lecture. Two composite HE have been studied. The first one is HMX - HTPB 82:18. The second one is HMX - NTO - HTPB 12:72:16. These HE have been submitted to plane sustained shock waves at different pressure levels using a laboratory powder gun. Pressure signals are measured using manganin gauges inserted at several distances inside HE. The corresponding run-distances to detonation are determined using wedge test experiments where the plate impact is performed using a powder gun. Both HE exhibit a single detonation buildup curve in the distance - time diagram of shock-to-detonation transition. This feature seems a common shock-to-detonation behavior for composite HE without porosity. This behavior is also confirmed for a RDX - HTPB 85:15 based composite HE. Such a behavior is exploited to determine the heterogeneous reaction rate versus the shock pressure using a method based on the Cauchy-Riemann problem inversion. The reaction rate laws obtained allow to compute both run-distance to detonation and pressure signals.

  16. PBX 9501 high explosive violent response/low amplitude insult project: Phase I

    SciTech Connect

    Idar, D.J.; Lucht, R.A.; Scammon, R.; Straight, J.; Skidmore, C.B.

    1997-01-01

    Preliminary modeling and experimental analyses of the violent reaction threshold of semi-heavily confined PBX 9501 to low velocity impact have been completed. Experimental threshold measurements were obtained with ten tests using a spigot gun design to launch a hemispherical projectile at the high explosive contained in stainless steel. Powder curves were determined for several gun barrel designs, powders, and projectile materials and have proven to be very reproducible over the range of 75 to 325 ft/s. A threshold velocity of approximately 246 ft/s for violent reaction of the PBX 9501 was determined with experimental gauge and switch measurements and the remaining physical test evidence. Preliminary analyses of the PBX 9501 samples retrieved from both unreacted and partially reacted targets have been completed. Core samples were obtained from the unreacted targets and submitted for density determinations. The subsequent analysis supports the concept that the PBX 9501 yields and fractures under the low velocity compression event to expand and fill the annular gap in the target design. Samples of PBX 9501 from the partially reacted targets were examined with scanning electron microscope and light microscope techniques. Increased evidence of mechanical twinning effects are noted in the HMX crystals from the partially reacted targets. Finite element calculations using DYNA213, with a modified ORION post processor, without reaction or chemistry models, were used to support the design of targets, to compare predictive analyses with experimental measurements, and to evaluate a proposed ignition criterion in a power law form for threshold to reaction with dependence on pressure, maximum shear strain rate, and time variables. The calculations show good agreement with the physical dent and deformation data from the remaining target evidence; however, they do not match the experimental pressure gauge measurements well.

  17. Molecular design and property prediction of high density polynitro[3.3.3]-propellane-derivatized frameworks as potential high explosives.

    PubMed

    Zhang, Qinghua; Zhang, Jiaheng; Qi, Xiujuan; Shreeve, Jean'ne M

    2014-11-13

    Research in energetic materials is now heavily focused on the design and synthesis of novel insensitive high explosives (IHEs) for specialized applications. As an effective and time-saving tool for screening potential explosive structures, computer simulation has been widely used for the prediction of detonation properties of energetic molecules with relatively high precision. In this work, a series of new polynitrotetraoxopentaaza[3.3.3]-propellane molecules with tricyclic structures were designed. Their properties as potential high explosives including density, heats of formation, detonation properties, impact sensitivity, etc., have been extensively evaluated using volume-based thermodynamic calculations and density functional theory (DFT).These new energetic molecules exhibit high densities of >1.82 g cm(-3), in which 1 gives the highest density of 2.04 g cm(-3). Moreover, most new materials show good detonation properties and acceptable impact sensitivities, in which 5 displays much higher detonation velocity (9482 m s(-1)) and pressure (43.9 GPa) than HMX and has a h50 value of 11 cm. These results are expected to facilitate the experimental synthesis of new-generation nitramine-based high explosives. PMID:25325391

  18. Field-based study of volcanic ash via visible and thermal high-speed imaging of explosive eruptions

    NASA Astrophysics Data System (ADS)

    Tournigand, Pierre-Yves; Taddeucci, Jacopo; Scarlato, Piergiorgio; Gaudin, Damien; Del Bello, Elisabetta

    2015-04-01

    Subaerial explosive volcanic activity ejects a mixture of gas-ash-pyroclasts in the atmosphere. Parameterizing the physical processes responsible for ash injection and plume dynamics is crucial to constrain numerical models and forecasts of potentially hazardous ash dispersal events. In this study we present preliminary results from a new method based on visible and thermal high-speed video processing from Strombolian and Vulcanian explosions. High-speed videos were recorded by a Optronis CR600x2 camera (1280x1024 pixels definition, 500 Hz frame rate) for the visible and by a FLIR SC655 (640x480 pixels definition, 50 Hz frame rate) for the thermal. Qualitatively, different dynamics of ash injection and dispersal can be identified. High speed cameras allow us to observe all the different phases during volcanic plume dispersion with a very good time resolution. Multiple features were already observed about volcanic plumes, but this tool give a better accuracy to our observations and allow us to better define previously observed features and to be able to identify new ones. Quantitatively before using our videos a pre-processing is needed which aim is to isolate the plume from the background by using different types of filters without altering the data, to allow us to use automated procedures to track volcanic plumes. In this study we extract data from these videos (plume height, velocity, temperature, mass, volume,...) using different software tools. Doing this allow us to be able to define and constrain main parameters and processes in function of the observed volcano and explosion type, but also to find correlations between parameters and establish empirical relations. We define range of values for each parameter and their respective impact on plume dynamics and stability, to be able to obtain characteristic fields of values for each case and link it to explosions type and evolution.

  19. New Mix Explosives for Explosive Welding

    NASA Astrophysics Data System (ADS)

    Andreevskikh, Leonid

    2011-06-01

    Suggested and tested were some mix explosives--powder mixtures of a brisant high explosive (HE = RDX, PETN) and an inert diluent (baking soda)--for use in explosive welding. RDX and PETN were selected in view of their high throwing ability and low critical diameter. Since the decomposition of baking soda yields a huge amount of gaseous products, its presence ensures (even at a low HE percentage) a throwing speed that is sufficient for realization of explosive welding, at a reduced brisant action of charge. Mix chargers containing 30-70 wt % HE (the rest baking soda) have been tested experimentally and optimized. For study of possibility to reduce critical diameter of HE mixture, the mixture was prepared where HE crystal sizes did not exceed 10 μm. The tests, which were performed with this HE, revealed that the mixture detonated stably with the velocity D ~ 2 km/s, if the layer thickness was d = 2 mm. The above explosives afford to markedly diminish deformations within the oblique impact zone and thus to carry out explosive welding of hollow items and thin metallic foils.

  20. Hand held explosives detection system

    DOEpatents

    Conrad, Frank J.

    1992-01-01

    The present invention is directed to a sensitive hand-held explosives detection device capable of detecting the presence of extremely low quantities of high explosives molecules, and which is applicable to sampling vapors from personnel, baggage, cargo, etc., as part of an explosives detection system.

  1. Efficient neutron generation from solid-nanoparticle explosions driven by DPSSL-pumped high-repetition rate femtosecond laser pulse

    NASA Astrophysics Data System (ADS)

    Watari, T.; Matsukado, K.; Sekine, T.; Takeuchi, Y.; Hatano, Y.; Yoshimura, R.; Satoh, N.; Nishihara, K.; Takagi, M.; Kawashima, T.

    2016-03-01

    We propose novel neutron source using high-intensity laser based on the cluster fusion scheme. We developed DPSSL-pumped high-repetition-rate 20-TW laser system and solid nanoparticle target for neutron generation demonstration. In our neutron generation experiment, high-energy deuterons were generated from coulomb explosion of CD solid- nanoparticles and neutrons were generated by DD fusion reaction. Efficient and stable neutron generation was obtained by irradiating an intense femtosecond laser pulse of >2×1018 W/cm2. A yield of ∼105 neutrons per shot was stably observed during 0.1-1 Hz continuous operation.

  2. Thallium-201 imaging and estimation of residual high grade astrocytoma

    SciTech Connect

    Stafford-Schuck, K.; Mountz, J.M.; McKeever, P.; Taren, J.; Beierwaltes, W.H.

    1987-09-01

    Thallium-201 brain imaging was performed on five patients as a method to differentiate persistent and/or recurrent viable Grades III and IV astrocytoma tissue from necrosis or post-therapy changes. Planar images of the head and heart were obtained in order to calculate the ratio of tumor counts to cardiac counts. The heart was chosen as the internal reference organ, as thallium uptake dynamics are reproducible under ordinary circumstances. The numerical estimation of thallium uptake in the brain tumor, expressed in terms of the tumor/cardiac index, correlated well with the clinical course in all five patients. By visual inspection, the initial computed tomographic (CT) and thallium images suggested that the tumors were approximately the same size. Follow-up thallium images were discordant with follow-up CT images. Computed tomography, in general, appeared to depict image alterations suggesting more extensive regrowth of tumor than the actual clinical status or thallium brain scans demonstrated. Histologic examination best correlated with thallium images. In one patient's course of imaging they were able to detect tumor recurrence, by means of thallium imaging, 4 months prior to its appearance on CT. When performed serially, the tumor/cardiac index may provide an estimate of residual tumor burden, which can help distinguish tumor recurrence from changes secondary to therapy.

  3. A high sensitivity real-time NVR monitor. [Nonvolatile Residue

    NASA Technical Reports Server (NTRS)

    Bowers, William D.; Chuan, R. L.

    1992-01-01

    The use of a temperature-controlled 200-MHz SAW resonator piezoelectric mass microbalance to monitor the mass of nonvolatile residue (NVR) deposited on its surface in real time is reported. The fundamental frequency of this device is mainly dependent on the configuration of the transducers and not on the thickness of the substrate. Therefore, higher operating frequencies can be achieved without reducing the thickness of the crystal. The real-time instrument was integrated onto a conventional stainless steel NVR plate and operated flawlessly over a 14-d period at Kennedy Space Center and successfully measured less than 1 ng/sq cm d NVR contamination. Contamination episodes detected by the instrument were correlated with scheduled activities on the test stand. Under the assumption of a baseline noise level of +/- 2 Hz, the absolute mass lower limit of detection would be 0.065 ng/sq cm. This would enable the detection of a daily NVR deposition rate of less than 0.1 ng/sq cm d.

  4. Surrogate Modeling of High-Fidelity Fracture Simulations for Real-Time Residual Strength Predictions

    NASA Technical Reports Server (NTRS)

    Spear, Ashley D.; Priest, Amanda R.; Veilleux, Michael G.; Ingraffea, Anthony R.; Hochhalter, Jacob D.

    2011-01-01

    A surrogate model methodology is described for predicting, during flight, the residual strength of aircraft structures that sustain discrete-source damage. Starting with design of experiment, an artificial neural network is developed that takes as input discrete-source damage parameters and outputs a prediction of the structural residual strength. Target residual strength values used to train the artificial neural network are derived from 3D finite element-based fracture simulations. Two ductile fracture simulations are presented to show that crack growth and residual strength are determined more accurately in discrete-source damage cases by using an elastic-plastic fracture framework rather than a linear-elastic fracture mechanics-based method. Improving accuracy of the residual strength training data does, in turn, improve accuracy of the surrogate model. When combined, the surrogate model methodology and high fidelity fracture simulation framework provide useful tools for adaptive flight technology.

  5. Instabilities and soot formation in high-pressure, rich, iso-octane-air explosion flames. 1. Dynamical structure

    SciTech Connect

    Lockett, R.D.; Woolley, R.

    2007-12-15

    Simultaneous OH planar laser-induced fluorescence (PLIF) and Rayleigh scattering measurements have been performed on 2-bar rich iso-octane-air explosion flames obtained in the optically accessible Leeds combustion bomb. Separate shadowgraph high-speed video images have been obtained from explosion flames under similar mixture conditions. Shadowgraph images, quantitative Rayleigh images, and normalized OH concentration images have been presented for a selection of these explosion flames. Normalized experimental equilibrium OH concentrations behind the flame fronts have been compared with normalized computed equilibrium OH concentrations as a function of equivalence ratio. The ratio of superequilibrium OH concentration in the flame front to equilibrium OH concentration behind the flame front reveals the response of the flame to the thermal-diffusive instability and the resistance of the flame front to rich quenching. Burned gas temperatures have been determined from the Rayleigh scattering images in the range 1.4{<=}{phi}{<=}1.9 and are found to be in good agreement with the corresponding predicted adiabatic flame temperatures. Soot formation was observed to occur behind deep cusps associated with large-wavelength cracks occurring in the flame front for equivalence ratio {phi}{>=}1.8 (C/O{>=}0.576). The reaction time-scale for iso-octane pyrolysis to soot formation has been estimated to be approximately 7.5-10 ms. (author)

  6. Description and validation of ERAD: An atmospheric dispersion model for high explosive detonations

    SciTech Connect

    Boughton, B.A.; DeLaurentis, J.M.

    1992-10-01

    The Explosive Release Atmospheric Dispersion (ERAD) model is a three-dimensional numerical simulation of turbulent atmospheric transport and diffusion. An integral plume rise technique is used to provide a description of the physical and thermodynamic properties of the cloud of warm gases formed when the explosive detonates. Particle dispersion is treated as a stochastic process which is simulated using a discrete time Lagrangian Monte Carlo method. The stochastic process approach permits a more fundamental treatment of buoyancy effects, calm winds and spatial variations in meteorological conditions. Computational requirements of the three-dimensional simulation are substantially reduced by using a conceptualization in which each Monte Carlo particle represents a small puff that spreads according to a Gaussian law in the horizontal directions. ERAD was evaluated against dosage and deposition measurements obtained during Operation Roller Coaster. The predicted contour areas average within about 50% of the observations. The validation results confirm the model`s representation of the physical processes.

  7. Modeling the viscoelastic and brittle fracture response of a high explosive in an Eulerian hydrocode

    SciTech Connect

    Clancy, S.P.; Johnson, J.N.; Burkett, M.W.

    1998-12-31

    A constitutive model that incorporates brittle-fracture-mechanics and viscoelastic material response for PBX-9501 has been developed and implemented in the two-dimensional hydrocode MESA. The hydrocode with the visco-cracking model has been applied to numerous low-rate deformation and low-speed impact events. Several low-speed impact experiments that have quantified the deformation to the explosive have been used to assess the hydrocode and model for this type of material response problem. Comparisons between MESA w/visco-cracking model calculations and experimentally measured mechanical deformation to the explosive showed that reasonable agreement was achieved for the measured magnitude of deformation but the deformation profiles/shapes were found to be different.

  8. A Multipathway Model for High Explosives and Barium Transport Using GoldSim

    NASA Astrophysics Data System (ADS)

    Newman, B. D.; Hickmott, D. D.; Keating, E. H.; Robinson, B. A.; Gard, M. O.

    2002-05-01

    Outfalls from High Explosives (HE) production sites at Los Alamos National Laboratory (LANL) discharged RDX, TNT, HMX, and barium contaminated waters onto a mesa /canyon system on the western edge of the Pajarito Plateau from 1944 to 1996. HE concentrations in surface soils ranged to over 20 wt.%, and HE in waters range to over 800 ug/L. HE in water is present in springs, surface waters, alluvial waters and deep perched (> 700 ft. depth) and possibly regional (> 1200 ft depth) groundwaters. Barium concentrations range to over 4 wt.% in sediments, and to over 5000 ug/L in spring and alluvial waters. Because of the size of contaminant inventories and observations of HE in the perched zone and possibly deeper, there has been concern that there may be a long-term risk at a downgradient drinking water supply well. To address this concern, a GoldSim multipathway model was developed to simulate transport of HE and barium from source areas to the supply well. The objectives of the modeling effort were to generate a preliminary assessment of potential concentrations at the supply well and to identify any model components/parameters that require additional characterization based on model sensitivity and uncertainty. The model evaluates two main source areas, one is controlled by flow through the mesa vadose zone, and the other by flow through the canyon vadose zone. The two vadose zone modules feed into a saturated zone module that terminates at a pumping well (drinking water) module. The hydrogeology of the site is extremely complex and includes a heterogeneous, unfractured/fractured tuff vadose zone geology, ponds, springs, alluvial aquifers, a perennial stream reach, and two deep aquifers. Because of this complexity, and limited characterization and contaminant inventory information, we used a stochastic approach to quantitatively represent model/parameter uncertainties. Model parameters were developed using a variety of information including flow and transport modeling

  9. The face hallucinating two-step framework using hallucinated high-resolution residual

    NASA Astrophysics Data System (ADS)

    Naleer, H. M. M.; Lu, Yao; An, Yaozu

    2011-06-01

    In video surveillance, the attention human faces are frequently of small size. Image hallucination is an imperative factor disturbing the face classification by human and computer. In this paper, we propose a two-step face hallucination framework by means of training data sets which have a small quantity of low and high resolution images. In the first step, the global face is constructed based on optimal weights of training images. In the second step, a local residual compensation method bases on position patch via residual training face image data sets. Moreover, the hallucinated highresolution residual image which is obtained by the identical process can be subsequent for the local face. Finally, the hallucinated high-resolution residual image is appended with the input low-resolution face image which is interpolated to the high-resolution image dimension by an upsampling factor. Experiments fully demonstrate that our framework is very flexible and accomplishs good performance via small training data sets.

  10. Modeling the Structural Response from a Propagating High Explosive Using Smooth Particle Hydrodynamics

    SciTech Connect

    Margraf, J

    2012-06-12

    This report primarily concerns the use of two massively parallel finite element codes originally written and maintained at Lawrence Livermore National Laboratory. ALE3D is an explicit hydrodynamics code commonly employed to simulate wave propagation from high energy scenarios and the resulting interaction with nearby structures. This coupled response ensures that a structure is accurately applied with a blast loading varying both in space and time. Figure 1 illustrates the radial outward propagation of a pressure wave due to a center detonated spherical explosive originating from the lower left. The radial symmetry seen in this scenario is lost when instead a cylindrocal charge is detonated. Figure 2 indicates that a stronger, faster traveling pressure wave occurs in the direction of the normal axis to the cylinder. The ALE3D name is derived because of the use of arbitrary-Lagrange-Eulerian elements in which the mesh is allowed to advect; a process through which the mesh is modified to alleviate tanlging and general mesh distortion often cuased by high energy scenarios. The counterpart to an advecting element is a Lagrange element, whose mesh moves with the material. Ideally all structural components are kept Lagrange as long as possible to preserve accuracy of material variables and minimize advection related errors. Advection leads to mixed zoning, so using structural Lagrange elements also improves the visualization when post processing the results. A simplified representation of the advection process is shown in Figure 3. First the mesh is distorted due to material motion during the Lagrange step. The mesh is then shifted to an idealized and less distorted state to prevent irregular zones caused by the Lagrange motion. Lastly, the state variables are remapped to the elements of the newly constructed mesh. Note that Figure 3 represents a purely Eulerian mesh relaxation because the mesh is relocated back to the pre-Lagrange position. This is the case when the

  11. Optically measured explosive impulse

    NASA Astrophysics Data System (ADS)

    Biss, Matthew M.; McNesby, Kevin L.

    2014-06-01

    An experimental technique is investigated to optically measure the explosive impulse produced by laboratory-scale spherical charges detonated in air. Explosive impulse has historically been calculated from temporal pressure measurements obtained via piezoelectric transducers. The presented technique instead combines schlieren flow visualization and high-speed digital imaging to optically measure explosive impulse. Prior to an explosive event, schlieren system calibration is performed using known light-ray refractions and resulting digital image intensities. Explosive charges are detonated in the test section of a schlieren system and imaged by a high-speed digital camera in pseudo-streak mode. Spatiotemporal schlieren intensity maps are converted using an Abel deconvolution, Rankine-Hugoniot jump equations, ideal gas law, triangular temperature decay profile, and Schardin's standard photometric technique to yield spatiotemporal pressure maps. Temporal integration of individual pixel pressure profiles over the positive pressure duration of the shock wave yields the explosive impulse generated for a given radial standoff. Calculated explosive impulses are shown to exhibit good agreement between optically derived values and pencil gage pressure transducers.

  12. APPLICATION OF THE EMBEDDED FIBER OPTIC PROBE IN HIGH EXPLOSIVE DETONATION STUDIES: PBX-9502 AND LX-17

    SciTech Connect

    Hare, D; Goosman, D; Lorenz, K; Lee, E

    2006-09-26

    The Embedded Fiber Optic probe directly measures detonation speed continuously in time, without the need to numerically differentiate data, and is a new tool for measuring time-dependent as well as steady detonation speed to high accuracy. It consists of a custom-design optical fiber probe embedded in high explosive. The explosive is detonated and a refractive index discontinuity is produced in the probe at the location of the detonation front by the compression of the detonation. Because this index-jump tracks the detonation front a measurement of the Doppler shift of laser light reflected from the jump makes it possible to continuously measure detonation velocity with high spatial and temporal resolution. We have employed this probe with a Fabry-Perot-type laser Doppler velocimetry system additionally equipped with a special filter for reducing the level of non-Doppler shifted light relative to the signal. This is necessary because the index-jump signal is relatively weak compared to the return expected from a well-prepared surface in the more traditional and familiar example of material interface velocimetry. Our observations were carried out on a number of explosives but this work is focused on our results on PBX-9502 (95% TATB, 5% Kel-F) and LX-17 (92.5% TATB, 7.5% Kel-F) at varying initial charge density. Our measurements reveal a density dependence significantly lower than previous quoted values and lower than theoretical calculations. Our limited data on detonation speed dependence on wave curvature is in reasonable agreement with previous work using more standard methods and confirms deviation from the Wood-Kirkwood theoretical formula.

  13. Optimizing amorphous indium zinc oxide film growth for low residual stress and high electrical conductivity

    NASA Astrophysics Data System (ADS)

    Kumar, Mukesh; Sigdel, A. K.; Gennett, T.; Berry, J. J.; Perkins, J. D.; Ginley, D. S.; Packard, C. E.

    2013-10-01

    With recent advances in flexible electronics, there is a growing need for transparent conductors with optimum conductivity tailored to the application and nearly zero residual stress to ensure mechanical reliability. Within amorphous transparent conducting oxide (TCO) systems, a variety of sputter growth parameters have been shown to separately impact film stress and optoelectronic properties due to the complex nature of the deposition process. We apply a statistical design of experiments (DOE) approach to identify growth parameter-material property relationships in amorphous indium zinc oxide (a-IZO) thin films and observed large, compressive residual stresses in films grown under conditions typically used for the deposition of highly conductive samples. Power, growth pressure, oxygen partial pressure, and RF power ratio (RF/(RF + DC)) were varied according to a full-factorial test matrix and each film was characterized. The resulting regression model and analysis of variance (ANOVA) revealed significant contributions to the residual stress from individual growth parameters as well as interactions of different growth parameters, but no conditions were found within the initial growth space that simultaneously produced low residual stress and high electrical conductivity. Extrapolation of the model results to lower oxygen partial pressures, combined with prior knowledge of conductivity-growth parameter relationships in the IZO system, allowed the selection of two promising growth conditions that were both empirically verified to achieve nearly zero residual stress and electrical conductivities >1480 S/cm. This work shows that a-IZO can be simultaneously optimized for high conductivity and low residual stress.

  14. Residual Stresses in High-Velocity Oxy-Fuel Metallic Coatings

    SciTech Connect

    Terry C. Totemeier; Richard N. Wright; W. David Swank

    2004-06-01

    X-ray based residual stress measurements were made on type 316 stainless steel and Fe3A1 coatings that were high-velocity oxy-fuel (HVOF) sprayed onto low-carbon and stainless steel substrates. Nominal coating thicknesses varied from 250 to 1500 mm. The effect of HVOF spray particle velocity on residual stress and deposition efficiency was assessed by preparing coatings at three different torch chamber pressures. The effect of substrate thickness on residual stress was determined by spraying coatings onto thick (6.4 mm) and thin (1.4 mm) substrates. Residual stresses were compressive for both coating materials and increased in magnitude with spray velocity. For coatings applied to thick substrates, near-surface residual stresses were essentially constant with increasing coating thickness. Difference in thermal expansion coefficient between low-carbon and stainless steels led to a 180 MPa difference in residual stress for Fe3A1 coatings. Deposition efficiency for both materials is maximized at an intermediate (~600 m/s) velocity. Considerations for X-ray measurement of residual stresses in HVOF coatings are also presented.

  15. Detonation of insensitive high explosives by a Q-switched ruby laser.

    NASA Technical Reports Server (NTRS)

    Yang, L. C.; Menichelli, V. J.

    1971-01-01

    Immediate longitudinal detonations have been observed in confined small-diameter columns of PETN, RDX, and tetryl by using a focused Q-switched ruby laser. The energy ranged from 0.8 to 4.0 J in a pulse width of 25 nsec. A 1000-A-thick aluminum film deposited on a glass window was used to generate a shock wave at the window-explosive interface when irradiated by the laser. In some cases, steady-state detonations were reached in less than .5 microsec with less than 10% variation in the detonation velocity.

  16. Infrasonic observations and modeling of the Minor Uncle High Explosive event

    SciTech Connect

    Whitaker, R.; Noel, S.D.; Meadows, W.R.

    1994-09-01

    Minor Uncle was a Department of Defense sponsored explosive test of 2440 tons of ammonium nitrate and fuel oil (ANFO) executed on June 10, 1993, at White Sands Missile Range, NM. Los Alamos National Laboratory made infrasonic observations of this event at three stations: Los Alamos, NM, 250 km range; St. George, UT, 750 km range; and the Nevada Test Site, NV, 928 km range. All three stations obtained positive results and had very low background noise levels. Data from all stations will be presented, and normal mode calculations of the wave propagation, including upper atmospheric winds, to St. George will be compared to the data.

  17. High-explosive cratering analogs for bowl-shaped, central uplift, and multiring impact craters

    NASA Technical Reports Server (NTRS)

    Roddy, D. J.

    1976-01-01

    The paper describes six experimental explosion craters in terms of their basic morphology, subsurface structural deformation, and surrounding ejecta blanket. These craters exhibit one or more of the following features: bowl shapes with underlying breccia lens, central uplifts, multirings, terraced walls, rim strata, zones of concentric rim deformation, inner continuous ground cover of ejecta blankets formed by overturned flaps, secondary cratering, and fused alluvium. These craters were formed by large shock wave energy transfers at or near zero heights-of-burst, and it is possible that impact craters with analogous morphologic and structural features may have formed under similar surface energy transfer conditions.

  18. A Risk Management Framework to Characterize Black Swan Risks: A Case Study of Lightning Effects on Insensitive High Explosives

    NASA Astrophysics Data System (ADS)

    Sanders, Gary A.

    Effective and efficient risk management processes include the use of high fidelity modeling and simulation during the concept exploration phase as part of the technology and risk assessment activities, with testing and evaluation tasks occurring in later design development phases. However, some safety requirements and design architectures may be dominated by the low probability/high consequence "Black Swan" vulnerabilities that require very early testing to characterize and efficiently mitigate. Failure to address these unique risks has led to catastrophic systems failures including the space shuttle Challenger, Deepwater Horizon, Fukushima nuclear reactor, and Katrina dike failures. Discovering and addressing these risks later in the design and development process can be very costly or even lead to project cancellation. This paper examines the need for risk management process adoption of early hazard phenomenology testing to inform the technical risk assessment, requirements definition and conceptual design. A case study of the lightning design vulnerability of the insensitive high explosives being used in construction, mining, demolition, and defense industries will be presented to examine the impact of this vulnerability testing during the concept exploration phase of the design effort. While these insensitive high explosives are far less sensitive to accidental initiation by fire, impact, friction or even electrical stimuli, their full range of sensitivities have not been characterized and ensuring safe engineering design and operations during events such as lightning storms requires vulnerability testing during the risk assessment phase.

  19. Explosive Entrances

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Explosive Technology, Inc. manufactured explosives first used by NASA to separate stages of the Gemini launch vehicle. When firemen need to get into a burning building or chop a hole to provide ventilation, axes can be devastatingly slow. Controlled explosives developed to separate manned upper stages of space rockets in case of mishap have been adapted to cutting emergency exits and demolishing unsafe buildings and bridges. Detonation cuts through thick steel girders or other materials more cleanly than torches or saws. This device can also cut emergency holes in airplanes and trains so surviving passengers can escape.

  20. Parametric Explosion Spectral Model

    SciTech Connect

    Ford, S R; Walter, W R

    2012-01-19

    Small underground nuclear explosions need to be confidently detected, identified, and characterized in regions of the world where they have never before occurred. We develop a parametric model of the nuclear explosion seismic source spectrum derived from regional phases that is compatible with earthquake-based geometrical spreading and attenuation. Earthquake spectra are fit with a generalized version of the Brune spectrum, which is a three-parameter model that describes the long-period level, corner-frequency, and spectral slope at high-frequencies. Explosion spectra can be fit with similar spectral models whose parameters are then correlated with near-source geology and containment conditions. We observe a correlation of high gas-porosity (low-strength) with increased spectral slope. The relationship between the parametric equations and the geologic and containment conditions will assist in our physical understanding of the nuclear explosion source.

  1. Skin explosion of double-layer conductors in fast-rising high magnetic fields

    SciTech Connect

    Chaikovsky, S. A. Datsko, I. M.; Labetskaya, N. A.; Ratakhin, N. A.

    2014-04-15

    An experiment has been performed to study the electrical explosion of thick cylindrical conductors using the MIG pulsed power generator capable of producing a peak current of 2.5 MA within 100 ns rise time. The experimental goal was to compare the skin explosion of a solid conductor with that of a double-layer conductor whose outer layer had a lower conductivity than the inner one. It has been shown that in magnetic fields of peak induction up to 300 T and average induction rise rate 3 × 10{sup 9} T/s, the double-layer structure of a conductor makes it possible to achieve higher magnetic induction at the conductor surface before it explodes. This can be accounted for, in particular, by the reduction of the ratio of the Joule heat density to the energy density of the magnetic field at the surface of a double-layer conductor due to redistribution of the current density over the conductor cross section.

  2. Mid-IR DIAL for high-resolution mapping of explosive precursors

    NASA Astrophysics Data System (ADS)

    Mitev, V.; Babichenko, S.; Bennes, J.; Borelli, R.; Dolfi-Bouteyre, A.; Fiorani, L.; Hespel, L.; Huet, T.; Palucci, A.; Pistilli, M.; Puiu, A.; Rebane, O.; Sobolev, I.

    2013-10-01

    A DIAL instrument on a moving platform is seen as a valuable remote sensing component in a sensor network for area monitoring, targeting sites involved in unauthorised explosive manufacturing. Such instrument will perform the area mapping of the vapour concentration of key substances, known to be used as precursors in explosive fabrication, such as acetone and nitromethane. The IR spectra of acetone and nitromethane vapours have been defined from available spectroscopy databases and from laboratory measurements as showing optimal spectral band for the DIAL operation in the spectral range of 3.0 μm - 3.5 μm. The DIAL operation has been numerically simulated, with inputs based on the HITRAN database, the U.S. Standard Atmosphere and aerosol simulation software package OPAC. A combination of OPO and OPA has been chosen as a transmitter, where the idler wavelength is used for probing, with wavelength tuning in sequence. A scanner mounted on top of the coaxially aligned laser and receiver, is capable of covering almost 360 degrees horizontally and +/-30 degrees vertically. The detection is performed by a photovoltaic photodiode with 4-stage cooling, with a signal digitalisation having 14 bit amplitude resolution and 125 Ms/s sampling rate. Here we present the development and the first test of the DIAL instrument.

  3. Numerical model investigation for potential methane explosion and benzene vapor intrusion associated with high-ethanol blend releases.

    PubMed

    Ma, Jie; Luo, Hong; Devaull, George E; Rixey, William G; Alvarez, Pedro J J

    2014-01-01

    Ethanol-blended fuel releases usually stimulate methanogenesis in the subsurface, which could pose an explosion risk if methane accumulates in a confined space above the ground where ignitable conditions exist. Ethanol-derived methane may also increase the vapor intrusion potential of toxic fuel hydrocarbons by stimulating the depletion of oxygen by methanotrophs, and thus inhibiting aerobic biodegradation of hydrocarbon vapors. To assess these processes, a three-dimensional numerical vapor intrusion model was used to simulate the degradation, migration, and intrusion pathway of methane and benzene under different site conditions. Simulations show that methane is unlikely to build up to pose an explosion hazard (5% v/v) if diffusion is the only mass transport mechanism through the deeper vadose zone. However, if methanogenic activity near the source zone is sufficiently high to cause advective gas transport, then the methane indoor concentration may exceed the flammable threshold under simulated conditions. During subsurface migration, methane biodegradation could consume soil oxygen that would otherwise be available to support hydrocarbon degradation, and increase the vapor intrusion potential for benzene. Vapor intrusion would also be exacerbated if methanogenic activity results in sufficiently high pressure to cause advective gas transport in the unsaturated zone. Overall, our simulations show that current approaches to manage the vapor intrusion risk for conventional fuel released might need to be modified when dealing with some high ethanol blend fuel (i.e., E20 up to E95) releases. PMID:24354291

  4. Explosive detection using high-volume vapor sampling and analysis by trained canines and ultra-trace detection equipment

    NASA Astrophysics Data System (ADS)

    Fisher, Mark; Sikes, John; Prather, Mark

    2004-09-01

    The dog's nose is an effective, highly-mobile sampling system, while the canine olfactory organs are an extremely sensitive detector. Having been trained to detect a wide variety of substances with exceptional results, canines are widely regarded as the 'gold standard' in chemical vapor detection. Historically, attempts to mimic the ability of dogs to detect vapors of explosives using electronic 'dogs noses' has proven difficult. However, recent advances in technology have resulted in development of detection (i.e., sampling and sensor) systems with performance that is rapidly approaching that of trained canines. The Nomadics Fido was the first sensor to demonstrate under field conditions the detection of landmines with performance approaching that of canines. More recently, comparative testing of Fido against canines has revealed that electronic vapor detection, when coupled with effective sampling methods, can produce results comparable to that of highly-trained canines. The results of these comparative tests will be presented, as will recent test results in which explosives hidden in cargo were detected using Fido with a high-volume sampling technique. Finally, the use of canines along with electronic sensors will be discussed as a means of improving the performance and expanding the capabilities of both methods.

  5. Summary of efficiency testing of standard and high-capacity high-efficiency particulate air filters subjected to simulated tornado depressurization and explosive shock waves

    SciTech Connect

    Smith, P.R.; Gregory, W.S.

    1985-04-01

    Pressure transients in nuclear facility air cleaning systems can originate from natural phenomena such as tornadoes or from accident-induced explosive blast waves. This study was concerned with the effective efficiency of high-efficiency particulate air (HEPA) filters during pressure surges resulting from simulated tornado and explosion transients. The primary objective of the study was to examine filter efficiencies at pressure levels below the point of structural failure. Both standard and high-capacity 0.61-m by 0.61-m HEPA filters were evaluated, as were several 0.2-m by 0.2-m HEPA filters. For a particular manufacturer, the material release when subjected to tornado transients is the same (per unit area) for both the 0.2-m by 0.2-m and the 0.61-m by 0.61-m filters. For tornado transients, the material release was on the order of micrograms per square meter. When subjecting clean HEPA filters to simulated tornado transients with aerosol entrained in the pressure pulse, all filters tested showed a degradation of filter efficiency. For explosive transients, the material release from preloaded high-capacity filters was as much as 340 g. When preloaded high-capacity filters were subjected to shock waves approximately 50% of the structural limit level, 1 to 2 mg of particulate was released.

  6. Characterization of ANFO explosive by high accuracy ESI(±)-FTMS with forensic identification on real samples by EASI(-)-MS.

    PubMed

    Hernandes, Vinicius Veri; Franco, Marcos Fernado; Santos, Jandyson Machado; Melendez-Perez, Jose J; de Morais, Damila Rodrigues; Rocha, Werickson Fortunato de Carvalho; Borges, Rodrigo; de Souza, Wanderley; Zacca, Jorge Jardim; Logrado, Lucio Paulo Lima; Eberlin, Marcos Nogueira; Correa, Deleon Nascimento

    2015-04-01

    Ammonium nitrate fuel oil (ANFO) is an explosive used in many civil applications. In Brazil, ANFO has unfortunately also been used in criminal attacks, mainly in automated teller machine (ATM) explosions. In this paper, we describe a detailed characterization of the ANFO composition and its two main constituents (diesel and a nitrate explosive) using high resolution and accuracy mass spectrometry performed on an FT-ICR-mass spectrometer with electrospray ionization (ESI(±)-FTMS) in both the positive and negative ion modes. Via ESI(-)-MS, an ion marker for ANFO was characterized. Using a direct and simple ambient desorption/ionization technique, i.e., easy ambient sonic-spray ionization mass spectrometry (EASI-MS), in a simpler, lower accuracy but robust single quadrupole mass spectrometer, the ANFO ion marker was directly detected from the surface of banknotes collected from ATM explosion theft. PMID:25700111

  7. Global disturbances of the ionosphere caused by the electric field from the high-altitude nuclear explosion 'Starfish' on July 9, 1962. I, II

    NASA Astrophysics Data System (ADS)

    Tsedilina, E. E.; Shashun'kina, V. M.

    1990-10-01

    The theory of the formation of an artifical radiation belt of high-energy electrons in the magnetosphere is used to examine possible ionospheric effects from the electric field generated by the Starfish nuclear test explosion over Johnston Island on July 9, 1962. A region in the Northern Hemisphere is identified where the explosion led to a drop in electron density in the F-region maximum by about 20 percent and a lowering of the layer by 20-30 km in the course of one hour after the explosion. The F-layer gradually came back to normal in the following hour. It is suggested that, in the initial period after the explosion, this effect was associated with the western electric field, which caused the lowering of the F-layer, as well as with changes in the recombination-diffusion balance in this layer.

  8. Paroxysmal dome explosion during the Merapi 2010 eruption: Processes and facies relationships of associated high-energy pyroclastic density currents

    NASA Astrophysics Data System (ADS)

    Komorowski, Jean-Christophe; Jenkins, Susanna; Baxter, Peter J.; Picquout, Adrien; Lavigne, Franck; Charbonnier, Sylvain; Gertisser, Ralf; Preece, Katie; Cholik, Noer; Budi-Santoso, Agus; Surono

    2013-07-01

    An 11-minute sequence of laterally-directed explosions and retrogressive collapses on 5 November 2010 at Merapi (Indonesia) destroyed a rapidly-growing dome and generated high-energy pyroclastic density currents (PDCs) spreading over 22 km2 with a runout of 8.4 km while contemporaneous co-genetic valley-confined PDCs reached 15.5 km. This event formed Stage 4 of the multi-stage 2010 eruption, the most intense eruptive episode at Merapi since 1872. The deposits and the widespread devastating impact of associated high-energy PDCs on trees and buildings show striking similarities with those from historical volcanic blasts (Montagne Pelée, Martinique, Bezymianny, Russia, Mount St. Helens, USA, Soufrière Hills, Montserrat). We provide data from stratigraphic and sedimentologic analyses of 62 sections of the first unequivocal blast-like deposits in Merapi's recent history. We used high resolution satellite imagery to map eruptive units and flow direction from the pattern of extensive tree blowdown. The stratigraphy of Stage 4 consists of three depositional units (U0, U1, U2) that we correlate to the second, third and fourth explosions of the seismic record. Both U1 and U2 show a bi-partite layer stratigraphy consisting each of a lower L1 layer and an upper L2 layer. The lower L1 layer is typically very coarse-grained, fines-poor, poorly-sorted and massive, and was deposited by the erosive waxing flow head. The overlying L2 layer is much finer grained, fines-rich, moderately to well-sorted, with laminar to wavy stratification. L2 was deposited from the waning upper part and wake of the PDC. Field observations indicate that PDC height reached ~ 330 m with an internal velocity of ~ 100 m s- 1 within 3 km from the source. The summit's geometry and the terrain morphology formed by a major transversal ridge and a funneling deep canyon strongly focused PDC mass towards a major constriction, thereby limiting the loss of kinetic energy. This favored elevated PDC velocities and

  9. Model-Based Development of a Small-Scale Experiment for Non-Shock Ignition of High Explosives

    NASA Astrophysics Data System (ADS)

    White, Bradley; Springer, H.; Reaugh, J.

    2013-06-01

    We demonstrate a model-based approach for developing small-scale experiments for non-shock ignition of high explosives (HEs) that are representative of abnormal environmental conditions. While small-scale experiments are often favored over large-scale testing since costs are lower and samples sizes are amenable to early stage HE formulation, concerns remain about the ability to predict full-scale non-shock ignition response. Our approach is to perform simulations of full-scale systems (i.e., Skid test) to identify the localized material extrema states (e.g., pressure, pressure duration, shear stress, strain-rate) underlying the non-shock ignition mechanism. The extrema states then provide a metric for iterative model-based development of small-scale experiments using a drop-hammer system. We performed these simulations using the HERMES (High Explosive Response to MEchanical Stimuli) model in the multiphysics code, ALE3D. Optimized experimental geometries reach 10s MPa pressures over 1-3 ms durations while inducing a large degree of shear. The results of the experimental development and the effects of design variations on non-shock initiation response of Comp B will be presented. This work performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344. This work was funded in part by the Joint DoD-DOE Munitions Program.

  10. Specific binding of eukaryotic ORC to DNA replication origins depends on highly conserved basic residues.

    PubMed

    Kawakami, Hironori; Ohashi, Eiji; Kanamoto, Shota; Tsurimoto, Toshiki; Katayama, Tsutomu

    2015-01-01

    In eukaryotes, the origin recognition complex (ORC) heterohexamer preferentially binds replication origins to trigger initiation of DNA replication. Crystallographic studies using eubacterial and archaeal ORC orthologs suggested that eukaryotic ORC may bind to origin DNA via putative winged-helix DNA-binding domains and AAA+ ATPase domains. However, the mechanisms how eukaryotic ORC recognizes origin DNA remain elusive. Here, we show in budding yeast that Lys-362 and Arg-367 residues of the largest subunit (Orc1), both outside the aforementioned domains, are crucial for specific binding of ORC to origin DNA. These basic residues, which reside in a putative disordered domain, were dispensable for interaction with ATP and non-specific DNA sequences, suggesting a specific role in recognition. Consistent with this, both residues were required for origin binding of Orc1 in vivo. A truncated Orc1 polypeptide containing these residues solely recognizes ARS sequence with low affinity and Arg-367 residue stimulates sequence specific binding mode of the polypeptide. Lys-362 and Arg-367 residues of Orc1 are highly conserved among eukaryotic ORCs, but not in eubacterial and archaeal orthologs, suggesting a eukaryote-specific mechanism underlying recognition of replication origins by ORC. PMID:26456755

  11. Specific binding of eukaryotic ORC to DNA replication origins depends on highly conserved basic residues

    PubMed Central

    Kawakami, Hironori; Ohashi, Eiji; Kanamoto, Shota; Tsurimoto, Toshiki; Katayama, Tsutomu

    2015-01-01

    In eukaryotes, the origin recognition complex (ORC) heterohexamer preferentially binds replication origins to trigger initiation of DNA replication. Crystallographic studies using eubacterial and archaeal ORC orthologs suggested that eukaryotic ORC may bind to origin DNA via putative winged-helix DNA-binding domains and AAA+ ATPase domains. However, the mechanisms how eukaryotic ORC recognizes origin DNA remain elusive. Here, we show in budding yeast that Lys-362 and Arg-367 residues of the largest subunit (Orc1), both outside the aforementioned domains, are crucial for specific binding of ORC to origin DNA. These basic residues, which reside in a putative disordered domain, were dispensable for interaction with ATP and non-specific DNA sequences, suggesting a specific role in recognition. Consistent with this, both residues were required for origin binding of Orc1 in vivo. A truncated Orc1 polypeptide containing these residues solely recognizes ARS sequence with low affinity and Arg-367 residue stimulates sequence specific binding mode of the polypeptide. Lys-362 and Arg-367 residues of Orc1 are highly conserved among eukaryotic ORCs, but not in eubacterial and archaeal orthologs, suggesting a eukaryote-specific mechanism underlying recognition of replication origins by ORC. PMID:26456755

  12. Gas-dynamic explosion of water microparticles under action high-power femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Zemlyanov, Alexander A.; Geints, Yuri E.; Apeksimov, Dmitrii V.

    2006-02-01

    Among the broad audience of problems of atmospheric nonlinear optics the important place is occupied with a problem about interaction of intensive laser radiation with water microparticles. Drops, being in a field of powerful light radiation, owing to effects of evaporation or explosion change the optical characteristics and influence on the optical properties of an environment. It results to that process and the distribution of intensive laser radiation in a particle is characterized by self-influence and is capable to change the internal power of a drop due to occurrence of areas of optical breakdown. In the report the model of destruction of water microparticles under action of supershort laser radiation is submitted. The physical contents of model is the effect of shock boiling up of a liquid at it gas-dynamic expansion from areas subject to optical breakdown.

  13. Quantitative understanding of explosive stimulus transfer

    NASA Technical Reports Server (NTRS)

    Schimmel, M. L.

    1973-01-01

    The mechanisms of detonation transfer across hermetically sealed interfaces created by necessary interruptions in high explosive trains, such as at detonators to explosive columns, field joints in explosive columns, and components of munitions fuse trains are demostrated. Reliability of detonation transfer is limited by minimizing explosive quantities, the use of intensitive explosives for safety, and requirements to propagate across gaps and angles dictated by installation and production restraints. The major detonation transfer variables studied were: explosive quanity, sensitivity, and thickness, and the separation distances between donor and acceptor explosives.

  14. Field screening of soils contaminated with explosives using ion mobility spectrometry

    SciTech Connect

    Crockett, A.B.; Atkinson, D.A.; Jenkins, T.F.

    1996-09-01

    Soils contaminated with explosives constitute a problem at DOE facilities and Army installations. Because explosives in soil are often heterogeneously distributed and require high density sampling, field screening is essential to characterize sites more quickly, economically and accurately. Current immunoassay and colorimetric field screening procedures have proven useful, but have significant per sample costs and limited throughput. At present, several field screening are available for TNT in soil, three procedures for RDX, and one procedure for 2,4-DNTand ammonium picrate/picric acid (AP/PA). Ion mobility spectrometry (IMS) has been used to detect explosives in air at ppt levels, but limited work has been done to apply the technique to quantify explosives in soils. The objective of this study has been to evaluate the utility of IMS as a screening technique for quantifying explosive residues in soils.

  15. Dynamics of the detonation products of a TATB based high explosive: Photon Doppler Velocimetry and high-speed digital shadowgraphy of expanding species

    NASA Astrophysics Data System (ADS)

    Sollier, Arnaud; Bouyer, Viviane; Terzulli, Louis-Pierre; Doucet, Michel; Hebert, Philippe; Decaris, Lionel

    2011-06-01

    The present investigation attempts to further improve our experimental characterization of the reaction zone in plastic bonded high explosives, by focusing on the dynamic of expansion of the detonation products during its initial stage. To this purpose, we performed measurements of the free surface velocity history of the detonating explosive using a PDV velocimeter system developped at CEA. We also used digital high-speed shadowgraphy to characterize the shape and speed of the products as they release from the bare charge free surface. In our experiments, we used cylindrical samples of an insensitive triaminotrinitrobenzene (TATB) composition having a density about 1.86 g/cc. Most of the experiments were performed in a cylindrical chamber under vacuum, but some shots were also performed with air at atmospheric conditions. The results of these experiments are compared with those of thin push-plate and explosive-window interface velocity measurements performed in the same conditions, which allow to give new insight into the reactions zone. Numerical simulations with different reactive flow models are also presented and found to be in good agreement with experiments.

  16. Detonation of highly dilute porous explosives; II: Influence of inert additives on the structure of the front, the parameters, and the reaction time

    SciTech Connect

    Shvedov, K.K.; Aniskin, A.I.; Dremin, A.N.; Il'in, A.N.

    1982-06-01

    For the detonation of porous explosives with inert additives, as for the detonation of individual porous explosives, the basic postulates and conclusions of the modern gasdynamic theory of detonation are valid. The influence of solid, refractory inert additives on the decomposition mechanism of porous explosives depends on the individual properties of the explosives and mainly on the dispersity of the additives. With the elimination of pronounced heating of the additives in mixtures with TNT, a certain positive influence on the appearance of decomposition sources and the total reaction time is observed. In cases with hexogen, no such influence is observed, which is evidently the result of physical inhomogeneity of the porous structure of the charge and the sufficiently high detonation pressures of the mixtures. The basic influence of inert additives on the critical diameter, front structure, detonation parameters, and reaction time of porous explosives is exerted through processes of energy absorption in the reaction region and factors leading to energy losses may lead to ambiguity of the detonation conditions in a system with specified chemical potential energy. The state of the additive in the reaction region must be taken into account for reliable theoretical description of the detonation conditions of porous explosives with a large content of inert additives.

  17. PUFF TOO: a residual stress experiment

    SciTech Connect

    Smith, C.W.

    1980-04-01

    Following the passage of the dynamic effects in a contained explosive detonation, there remains a strong compressive stress field in the material about the cavity. In this experiment, a 454-kg (1000 lb) sphere of high explosive was detonated in saturated ashfall tuff. Instrumentation measured peak stresses over the range of 0.1 to 6.0 GPa (1 to 6 kbar) and the complete stress-time waveform, including the so-called residual stress, at the 0.1 GPa (1 kbar) peak stress range. Mineback revealed detonation-induced fractures and fractures induced by postevent work.

  18. Development of highly sensitive and selective antibodies for the detection of the explosive pentaerythritol tetranitrate (PETN) by bioisosteric replacement.

    PubMed

    Hesse, Almut; Biyikal, Mustafa; Rurack, Knut; Weller, Michael G

    2016-02-01

    An improved antibody against the explosive pentaerythritol tetranitrate (PETN) was developed. The immunogen was designed by the concept of bioisosteric replacement, which led to an excellent polyclonal antibody with extreme selectivity and immunoassays of very good sensitivity. Compounds such as nitroglycerine, 2,4,6-trinitrotoluene, 1,3,5-trinitrobenzene, hexogen (RDX), 2,4,6-trinitroaniline, 1,3-dinitrobenzene, octogen (HMX), triacetone triperoxide, ammonium nitrate, 2,4,6-trinitrophenol and nitrobenzene were tested for potential cross-reactivity. The detection limit of a competitive enzyme-linked immunosorbent assay was determined to be around 0.5 µg/l. The dynamic range of the assay was found to be between 1 and 1000 µg/l, covering a concentration range of three decades. This work shows the successful application of the bioisosteric concept in immunochemistry by exchange of a nitroester to a carbonate diester. The antiserum might be used for the development of quick tests, biosensors, microtitration plate immunoassays, microarrays and other analytical methods for the highly sensitive detection of PETN, an explosive frequently used by terrorists, exploiting the extreme difficulty of its detection. PMID:26463875

  19. Flumethrin residue levels in honey from apiaries of China by high-performance liquid chromatography.

    PubMed

    Yu, L S; Liu, F; Wu, H; Tan, H R; Ruan, X C; Chen, Y; Chao, Z

    2015-01-01

    A method for detection of flumethrin residue in honey by high-performance liquid chromatography was established. After n-hexane-dichloromethane (4:6, vol/vol) extraction, the honey samples were concentrated by rotary evaporation, purified by an Oasis HLB solid-phase extraction column, and detected using a UV detector at 267 nm. The interference of the matrix was greatly reduced by optimizing pretreatment conditions; thus, the minimal detection limit of cyhalothrin was 0.005 mg/kg, the average recovery was 80.8 to 96.8%, and the coefficient of variation was 0.6 to 1.5%. The precision and reproducibility of this method was suitable and applicable for detecting flumethrin residue in honey. With this method, 135 honey samples from seven locations in the People's Republic of China were tested; 77 samples tested positive for flumethrin residue, resulting in a detection rate of 75.3%. Samples from the Guangdong province had the highest flumethrin residue level (0.122 mg/kg) of the locations tested. On the basis of analytical validation, the high-performance liquid chromatography has been shown to be a promising alternative for the analysis of flumethrin residue in honey samples. PMID:25581190

  20. Neutron diffraction analysis of residual strain/stress distribution in the vicinity of high strength welds

    NASA Astrophysics Data System (ADS)

    Mráz, L.; Karlsson, L.; Hamák, I.; Vrána, M.; Mikula, P.

    2010-06-01

    Residual stresses resulting from non homogeneous heat distribution during welding process belong to most significant factor influencing behavior of welded structures. These stresses are responsible for defect occurrence during welding and they are also responsible for crack initiation and propagation at the either static or dynamic load. The significant effect of weld metal chemical composition as well as the effect of fatigue load and local plastic deformation on residual stress distribution and fatigue life have been recognized for high strength steels welds. The changes in residual stress distribution have then positive effect on cold cracking behavior and also on fatigue properties of the welds [1-3]. Several experimental methods, both destructive and non-destructive, such as hole drilling method, X-ray diffraction, neutron diffraction and others, have been used to examine residual stress distribution in all three significant orientations in the vicinity of the welds. The present contribution summarizes the results of neutron diffraction measurements of residual stress distribution in the vicinity of single-pass high-strength-steel welds having different chemical composition as well as the influence of fatigue load and local plastic deformation. It has been observed that the chemical composition of the weld metal has a significant influence on the stress distribution around the weld. Similarly, by aplying both cyclic load or pre-stress load on the specimens, stress relaxation was observed even in the region of approximately 40 mm far from the weld toe.

  1. High-Order Hyperbolic Residual-Distribution Schemes on Arbitrary Triangular Grids

    NASA Technical Reports Server (NTRS)

    Mazaheri, Alireza; Nishikawa, Hiroaki

    2015-01-01

    In this paper, we construct high-order hyperbolic residual-distribution schemes for general advection-diffusion problems on arbitrary triangular grids. We demonstrate that the second-order accuracy of the hyperbolic schemes can be greatly improved by requiring the scheme to preserve exact quadratic solutions. We also show that the improved second-order scheme can be easily extended to third-order by further requiring the exactness for cubic solutions. We construct these schemes based on the LDA and the SUPG methodology formulated in the framework of the residual-distribution method. For both second- and third-order-schemes, we construct a fully implicit solver by the exact residual Jacobian of the second-order scheme, and demonstrate rapid convergence of 10-15 iterations to reduce the residuals by 10 orders of magnitude. We demonstrate also that these schemes can be constructed based on a separate treatment of the advective and diffusive terms, which paves the way for the construction of hyperbolic residual-distribution schemes for the compressible Navier-Stokes equations. Numerical results show that these schemes produce exceptionally accurate and smooth solution gradients on highly skewed and anisotropic triangular grids, including curved boundary problems, using linear elements. We also present Fourier analysis performed on the constructed linear system and show that an under-relaxation parameter is needed for stabilization of Gauss-Seidel relaxation.

  2. Detection of Unexpected High Correlations between Balance Calibration Loads and Load Residuals

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.; Volden, T.

    2014-01-01

    An algorithm was developed for the assessment of strain-gage balance calibration data that makes it possible to systematically investigate potential sources of unexpected high correlations between calibration load residuals and applied calibration loads. The algorithm investigates correlations on a load series by load series basis. The linear correlation coefficient is used to quantify the correlations. It is computed for all possible pairs of calibration load residuals and applied calibration loads that can be constructed for the given balance calibration data set. An unexpected high correlation between a load residual and a load is detected if three conditions are met: (i) the absolute value of the correlation coefficient of a residual/load pair exceeds 0.95; (ii) the maximum of the absolute values of the residuals of a load series exceeds 0.25 % of the load capacity; (iii) the load component of the load series is intentionally applied. Data from a baseline calibration of a six-component force balance is used to illustrate the application of the detection algorithm to a real-world data set. This analysis also showed that the detection algorithm can identify load alignment errors as long as repeat load series are contained in the balance calibration data set that do not suffer from load alignment problems.

  3. Mechanisms of large strain, high strain rate plastic flow in the explosively driven collapse of Ni-Al laminate cylinders

    NASA Astrophysics Data System (ADS)

    Olney, K. L.; Chiu, P. H.; Higgins, A.; Serge, M.; Weihs, T. P.; Fritz, G.; Stover, A.; Benson, D. J.; Nesterenko, V. F.

    2014-05-01

    Ni-Al laminates have shown promise as reactive materials due to their high energy release through intermetallic reaction. In addition to the traditional ignition methods, the reaction may be initiated in hot spots that can be created during mechanical loading. The explosively driven thick walled cylinder (TWC) technique was performed on two Ni-Al laminates composed of thin foil layers with different mesostructues: concentric and corrugated. These experiments were conducted to examine how these materials accommodate large plastic strain under high strain rates. Finite element simulations of these specimens with mesostuctures digitized from the experimental samples were conducted to provide insight into the mesoscale mechanisms of plastic flow. The dependence of dynamic behaviour on mesostructure may be used to tailor the hot spot formation and therefore the reactivity of the material system.

  4. High luminosity, slow ejecta and persistent carbon lines: SN 2009dc challenges thermonuclear explosion scenarios

    NASA Astrophysics Data System (ADS)

    Taubenberger, S.; Benetti, S.; Childress, M.; Pakmor, R.; Hachinger, S.; Mazzali, P. A.; Stanishev, V.; Elias-Rosa, N.; Agnoletto, I.; Bufano, F.; Ergon, M.; Harutyunyan, A.; Inserra, C.; Kankare, E.; Kromer, M.; Navasardyan, H.; Nicolas, J.; Pastorello, A.; Prosperi, E.; Salgado, F.; Sollerman, J.; Stritzinger, M.; Turatto, M.; Valenti, S.; Hillebrandt, W.

    2011-04-01

    Extended optical and near-IR observations reveal that SN 2009dc shares a number of similarities with normal Type Ia supernovae (SNe Ia), but is clearly overluminous, with a (pseudo-bolometric) peak luminosity of log (L) = 43.47 (erg s-1). Its light curves decline slowly over half a year after maximum light [Δm15(B)true= 0.71], and the early-time near-IR light curves show secondary maxima, although the minima between the first and the second peaks are not very pronounced. The bluer bands exhibit an enhanced fading after ˜200 d, which might be caused by dust formation or an unexpectedly early IR catastrophe. The spectra of SN 2009dc are dominated by intermediate-mass elements and unburned material at early times, and by iron-group elements at late phases. Strong C II lines are present until ˜2 weeks past maximum, which is unprecedented in thermonuclear SNe. The ejecta velocities are significantly lower than in normal and even subluminous SNe Ia. No signatures of interaction with a circumstellar medium (CSM) are found in the spectra. Assuming that the light curves are powered by radioactive decay, analytic modelling suggests that SN 2009dc produced ˜1.8 M⊙ of 56Ni assuming the smallest possible rise time of 22 d. Together with a derived total ejecta mass of ˜2.8 M⊙, this confirms that SN 2009dc is a member of the class of possible super-Chandrasekhar-mass SNe Ia similar to SNe 2003fg, 2006gz and 2007if. A study of the hosts of SN 2009dc and other superluminous SNe Ia reveals a tendency of these SNe to explode in low-mass galaxies. A low metallicity of the progenitor may therefore be an important prerequisite for producing superluminous SNe Ia. We discuss a number of possible explosion scenarios, ranging from super-Chandrasekhar-mass white-dwarf progenitors over dynamical white-dwarf mergers and Type I? SNe to a core-collapse origin of the explosion. None of the models seems capable of explaining all properties of SN 2009dc, so that the true nature of this SN

  5. Measurement of carbon condensates using small-angle x-ray scattering during detonation of the high explosive hexanitrostilbene

    SciTech Connect

    Bagge-Hansen, M.; Lauderbach, L.; Hodgin, R.; Bastea, S.; Fried, L.; Jones, A.; Buuren, T. van; Hansen, D.; Benterou, J.; May, C.; Willey, T. M.; Graber, T.; Jensen, B. J.; Ilavsky, J.

    2015-06-28

    The dynamics of carbon condensation in detonating high explosives remains controversial. Detonation model validation requires data for processes occurring at nanometer length scales on time scales ranging from nanoseconds to microseconds. A new detonation endstation has been commissioned to acquire and provide time-resolved small-angle x-ray scattering (SAXS) from detonating explosives. Hexanitrostilbene (HNS) was selected as the first to investigate due to its ease of initiation using exploding foils and flyers, vacuum compatibility, high thermal stability, and stoichiometric carbon abundance that produces high carbon condensate yields. The SAXS data during detonation, collected with 300 ns time resolution, provide unprecedented signal fidelity over a broad q-range. This fidelity permits the first analysis of both the Guinier and Porod/power-law regions of the scattering profile during detonation, which contains information about the size and morphology of the resultant carbon condensate nanoparticles. To bolster confidence in these data, the scattering angle and intensity were additionally cross-referenced with a separate, highly calibrated SAXS beamline. The data show that HNS produces carbon particles with a radius of gyration of 2.7 nm in less than 400 ns after the detonation front has passed, and this size and morphology are constant over the next several microseconds. These data directly contradict previous pioneering work on RDX/TNT mixtures and TATB, where observations indicate significant particle growth (50% or more) continues over several microseconds. The power-law slope is about −3, which is consistent with a complex disordered, irregular, or folded sp{sup 2} sub-arrangement within a relatively monodisperse structure possessing radius of gyration of 2.7 nm after the detonation of HNS.

  6. Measurement of carbon condensates using small-angle x-ray scattering during detonation of the high explosive hexanitrostilbene

    DOE PAGESBeta

    Bagge-Hansen, M.; Lauderbach, L.; Hodgin, R.; Bastea, S.; Fried, L.; Jones, A.; van Buuren, T.; Hansen, D.; Benterou, J.; May, C.; et al

    2015-06-24

    In this study, the dynamics of carbon condensation in detonating high explosives remains controversial. Detonation model validation requires data for processes occurring at nanometer length scales on time scales ranging from nanoseconds to microseconds. A new detonation end station has been commissioned to acquire and provide time-resolved small-angle x-ray scattering (SAXS) from detonating explosives. Hexanitrostilbene (HNS) was selected as the first to investigate due to its ease of initiation using exploding foils and flyers, vacuum compatibility, high thermal stability, and stoichiometric carbon abundance that produces high carbon condensate yields. The SAXS data during detonation, collected with 300 ns time resolution,more » provide unprecedented signal fidelity over a broad q-range. This fidelity permits the first analysis of both the Guinier and Porod/power-law regions of the scattering profile during detonation, which contains information about the size and morphology of the resultant carbon condensate nanoparticles. To bolster confidence in these data, the scattering angle and intensity were additionally cross-referenced with a separate, highly calibrated SAXS beamline. The data show that HNS produces carbon particles with a radius of gyration of 2.7 nm in less than 400 ns after the detonation front has passed, and this size and morphology are constant over the next several microseconds. These data directly contradict previous pioneering work on RDX/TNT mixtures and TATB, where observations indicate significant particle growth (50% or more) continues over several microseconds. The power-law slope is about -3, which is consistent with a complex disordered, irregular, or folded sp2 sub-arrangement within a relatively monodisperse structure possessing radius of gyration of 2.7 nm after the detonation of HNS.« less

  7. Measurement of carbon condensates using small-angle x-ray scattering during detonation of the high explosive hexanitrostilbene

    SciTech Connect

    Bagge-Hansen, M.; Lauderbach, L.; Hodgin, R.; Bastea, S.; Fried, L.; Jones, A.; van Buuren, T.; Hansen, D.; Benterou, J.; May, C.; Graber, T.; Jensen, B. J.; Ilavsky, J.; Willey, T. M.

    2015-06-24

    In this study, the dynamics of carbon condensation in detonating high explosives remains controversial. Detonation model validation requires data for processes occurring at nanometer length scales on time scales ranging from nanoseconds to microseconds. A new detonation end station has been commissioned to acquire and provide time-resolved small-angle x-ray scattering (SAXS) from detonating explosives. Hexanitrostilbene (HNS) was selected as the first to investigate due to its ease of initiation using exploding foils and flyers, vacuum compatibility, high thermal stability, and stoichiometric carbon abundance that produces high carbon condensate yields. The SAXS data during detonation, collected with 300 ns time resolution, provide unprecedented signal fidelity over a broad q-range. This fidelity permits the first analysis of both the Guinier and Porod/power-law regions of the scattering profile during detonation, which contains information about the size and morphology of the resultant carbon condensate nanoparticles. To bolster confidence in these data, the scattering angle and intensity were additionally cross-referenced with a separate, highly calibrated SAXS beamline. The data show that HNS produces carbon particles with a radius of gyration of 2.7 nm in less than 400 ns after the detonation front has passed, and this size and morphology are constant over the next several microseconds. These data directly contradict previous pioneering work on RDX/TNT mixtures and TATB, where observations indicate significant particle growth (50% or more) continues over several microseconds. The power-law slope is about -3, which is consistent with a complex disordered, irregular, or folded sp2 sub-arrangement within a relatively monodisperse structure possessing radius of gyration of 2.7 nm after the detonation of HNS.

  8. Measurement of carbon condensation using small-angle x-ray scattering during detonation of the high explosive hexanitrostilbene

    SciTech Connect

    Bagge-Hansen, M.; Lauderbach, L. M.; Hodgin, R.; Bastea, S.; Fried, L.; Jones, A.; van Buuren, T.; Hansen, D.; Benterou, J.; May, C.; Graber, T.; Jensen, B. J.; Ilavsky, J.; Willey, T. M.

    2015-06-24

    The dynamics of carboncondensation in detonating high explosives remains controversial. Detonation model validation requires data for processes occurring at nanometer length scales on time scales ranging from nanoseconds to microseconds. A new detonation endstation has been commissioned to acquire and provide time-resolved small-angle x-ray scattering (SAXS) from detonating explosives. Hexanitrostilbene (HNS) was selected as the first to investigate due to its ease of initiation using exploding foils and flyers, vacuum compatibility, high thermal stability, and stoichiometric carbon abundance that produces high carbon condensate yields. The SAXS data during detonation, collected with 300 ns time resolution, provide unprecedented signal fidelity over a broad q-range. This fidelity permits the first analysis of both the Guinier and Porod/power-law regions of the scattering profile during detonation, which contains information about the size and morphology of the resultant carbon condensate nanoparticles. To bolster confidence in these data, the scattering angle and intensity were additionally cross-referenced with a separate, highly calibrated SAXS beamline. The data show that HNS produces carbon particles with a radius of gyration of 2.7 nm in less than 400 ns after the detonation front has passed, and this size and morphology are constant over the next several microseconds. These data directly contradict previous pioneering work on RDX/TNT mixtures and TATB, where observations indicate significant particle growth (50% or more) continues over several microseconds. As a result, the power-law slope is about –3, which is consistent with a complex disordered, irregular, or folded sp2 sub-arrangement within a relatively monodisperse structure possessing radius of gyration of 2.7 nm after the detonation of HNS.

  9. Measurement of carbon condensates using small-angle x-ray scattering during detonation of the high explosive hexanitrostilbene

    NASA Astrophysics Data System (ADS)

    Bagge-Hansen, M.; Lauderbach, L.; Hodgin, R.; Bastea, S.; Fried, L.; Jones, A.; van Buuren, T.; Hansen, D.; Benterou, J.; May, C.; Graber, T.; Jensen, B. J.; Ilavsky, J.; Willey, T. M.

    2015-06-01

    The dynamics of carbon condensation in detonating high explosives remains controversial. Detonation model validation requires data for processes occurring at nanometer length scales on time scales ranging from nanoseconds to microseconds. A new detonation endstation has been commissioned to acquire and provide time-resolved small-angle x-ray scattering (SAXS) from detonating explosives. Hexanitrostilbene (HNS) was selected as the first to investigate due to its ease of initiation using exploding foils and flyers, vacuum compatibility, high thermal stability, and stoichiometric carbon abundance that produces high carbon condensate yields. The SAXS data during detonation, collected with 300 ns time resolution, provide unprecedented signal fidelity over a broad q-range. This fidelity permits the first analysis of both the Guinier and Porod/power-law regions of the scattering profile during detonation, which contains information about the size and morphology of the resultant carbon condensate nanoparticles. To bolster confidence in these data, the scattering angle and intensity were additionally cross-referenced with a separate, highly calibrated SAXS beamline. The data show that HNS produces carbon particles with a radius of gyration of 2.7 nm in less than 400 ns after the detonation front has passed, and this size and morphology are constant over the next several microseconds. These data directly contradict previous pioneering work on RDX/TNT mixtures and TATB, where observations indicate significant particle growth (50% or more) continues over several microseconds. The power-law slope is about -3, which is consistent with a complex disordered, irregular, or folded sp2 sub-arrangement within a relatively monodisperse structure possessing radius of gyration of 2.7 nm after the detonation of HNS.

  10. Identification of Critical Paraoxonase 1 Residues Involved in High Density Lipoprotein Interaction.

    PubMed

    Gu, Xiaodong; Huang, Ying; Levison, Bruce S; Gerstenecker, Gary; DiDonato, Anthony J; Hazen, Leah B; Lee, Joonsue; Gogonea, Valentin; DiDonato, Joseph A; Hazen, Stanley L

    2016-01-22

    Paraoxonase 1 (PON1) is a high density lipoprotein (HDL)-associated protein with atherosclerosis-protective and systemic anti-oxidant functions. We recently showed that PON1, myeloperoxidase, and HDL bind to one another in vivo forming a functional ternary complex (Huang, Y., Wu, Z., Riwanto, M., Gao, S., Levison, B. S., Gu, X., Fu, X., Wagner, M. A., Besler, C., Gerstenecker, G., Zhang, R., Li, X. M., Didonato, A. J., Gogonea, V., Tang, W. H., et al. (2013) J. Clin. Invest. 123, 3815-3828). However, specific residues on PON1 involved in the HDL-PON1 interaction remain unclear. Unambiguous identification of protein residues involved in docking interactions to lipid surfaces poses considerable methodological challenges. Here we describe a new strategy that uses a novel synthetic photoactivatable and click chemistry-taggable phospholipid probe, which, when incorporated into HDL, was used to identify amino acid residues on PON1 that directly interact with the lipoprotein phospholipid surface. Several specific PON1 residues (Leu-9, Tyr-185, and Tyr-293) were identified through covalent cross-links with the lipid probes using affinity isolation coupled to liquid chromatography with on-line tandem mass spectrometry. Based upon the crystal structure for PON1, the identified residues are all localized in relatively close proximity on the surface of PON1, defining a domain that binds to the HDL lipid surface. Site-specific mutagenesis of the identified PON1 residues (Leu-9, Tyr-185, and Tyr-293), coupled with functional studies, reveals their importance in PON1 binding to HDL and both PON1 catalytic activity and stability. Specifically, the residues identified on PON1 provide important structural insights into the PON1-HDL interaction. More generally, the new photoactivatable and affinity-tagged lipid probe developed herein should prove to be a valuable tool for identifying contact sites supporting protein interactions with lipid interfaces such as found on cell membranes

  11. MANAGING NITROGEN FOR COTTON IN A HIGH-RESIDUE CONSERVATION TILLAGE SYSTEM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 70% of the cotton (Gossypium hirsutum L.) in the Tennessee Valley of northern Alabama is currently raised using conservation tillage techniques. High-residue small grain cover crops are becoming a common tool in these systems, but N immobilization may occur causing previous N recommendations t...

  12. Cotton nitrogen management in a high-residue conservation system: source, rate, method, and timing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 70% of the 94,226 ha of cotton (Gossypium hirsutum L.) in the Tennessee Valley of northern Alabama, USA, is produced using conservation tillage systems with cereal cover crops. Decreased N efficiency, as a result of N immobilization and/or ammonia volatilization in high-residue systems, require...

  13. NITROGEN MANAGEMENT FOR COTTON GROWN IN A HIGH-RESIDUE COVER CROP CONSERVATION TILLAGE SYSTEM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 70% of the cotton (Gossypium hirsutum L.) in the Tennessee Valley of northern Alabama is currently raised using conservation tillage techniques. High-residue small grain cover crops are becoming a common tool in these systems, but N immobilization may occur causing previous N recommendations t...

  14. HIGH-THROUGHPUT IDENTIFICATION OF CATALYTIC REDOX-ACTIVE CYSTEINE RESIDUES

    EPA Science Inventory

    Cysteine (Cys) residues often play critical roles in proteins; however, identification of their specific functions has been limited to case-by-case experimental approaches. We developed a procedure for high-throughput identification of catalytic redox-active Cys in proteins by se...

  15. Determination of Thermal Properties and Morphology of Eucalyptus Wood Residue Filled High Density Polyethylene Composites

    PubMed Central

    Mengeloglu, Fatih; Kabakci, Ayse

    2008-01-01

    Thermal behaviors of eucalyptus wood residue (EWR) filled recycled high density polyethylene (HDPE) composites have been measured applying the thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Morphology of the materials was also studied using scanning electron microscope (SEM). Addition of the EWR into the recycled HDPE matrix reduced the starting of degradation temperature. EWR filled recycled HDPE had two main decomposition peaks, one for EWR around 350 °C and one for recycled HDPE around 460 °C. Addition of EWR did not affect the melting temperature of the recycled HDPE. Morphological study showed that addition of coupling agent improved the compatibility between wood residue and recycled HDPE. PMID:19325736

  16. Tin particle size measurements in high explosively driven shockwave experiments using Mie scattering method

    NASA Astrophysics Data System (ADS)

    Monfared, Shabnam; Buttler, William; Schauer, Martin; Lalone, Brandon; Pack, Cora; Stevens, Gerald; Stone, Joseph; Special Technologies Laboratory Collaboration; Los Alamos National Laboratory Team

    2014-03-01

    Los Alamos National Laboratory is actively engaged in the study of material failure physics to support the hydrodynamic models development, where an important failure mechanism of explosively shocked metals causes mass ejection from the backside of a shocked surface with surface perturbations. Ejecta models are in development for this situation. Our past work has clearly shown that the total ejected mass and mass-velocity distribution sensitively link to the wavelength and amplitude of these perturbations. While we have had success developing ejecta mass and mass-velocity models, we need to better understand the size and size-velocity distributions of the ejected mass. To support size measurements we have developed a dynamic Mie scattering diagnostic based on a CW laser that permits measurement of the forward attenuation cross-section combined with a dynamic mass-density and mass-velocity distribution, as well as a measurement of the forward scattering cross-section at 12 angles (5- 32.5 degrees) in increments of 2.5 degrees. We compare size distribution followed from Beers law with attenuation cross-section and mass measurement to the dynamic size distribution determined from scattering cross-section alone. We report results from our first quality experiments.

  17. Equation of state formulation for unreacted solid high explosives, PETN and HMX

    NASA Astrophysics Data System (ADS)

    Nagayama, Kunihito

    2015-06-01

    Equation of state (EOS) for unreacted explosives has been formulated thermodynamically aiming at using with numerical code of SDT processes. A generalized form of EOS is given in terms of p-v-E from the available static isothermal compression curve with non-constant specific heat, and arbitrary Grüneisen volume function. In this paper, a procedure of providing p-v-E EOS is developed based on the specific heat at constant volume as a function of entropy, Grüneisen volume function, together with Birch-Murnagan form of the isotherm. Material function of EOS and shock Hugoniot for PETN and HMX has been calculated, which is compared with the experimental data of shock-particle velocity Hugoniot. Dependence of shock pressure and temperature on the Grüneisen volume function is discussed. Insensitivity of the shock-particle velocity relationship to functional form of Grüneisen volume function is also shown. Second author: Dr. Shiro Kubota (AIST Japan).

  18. Phenomenon of Energy Focusing in Explosive Systems which include High Modulus Elastic Elements

    NASA Astrophysics Data System (ADS)

    Balagansky, I.; Hokamoto, K.; Manikandan, P.; Matrosov, A.; Stadnichenko, I.; Miyoshi, H.

    2009-06-01

    The phenomenon was observed in a passive HE charge of cast Comp. B without cumulative shape under shock wave loading by explosion of an active HE charge through water after preliminary compression by a leading wave in silicon carbide insert. The phenomenon manifested itself as a hole in identification steel specimen with depth of about 10 mm and diameter of about 5 mm. Results of experiments on studying of conditions of implementation of this phenomenon for SEP and Comp. B are presented. For each HE a number of experiments has been executed at various length of silicon carbide insert. Presence or absence of a hole in the steel specimen was determined. Also a number of optical registrations of process in framing mode with record step of 1 μs have been executed. Digital video camera SHIMADZU HPV-1 was used for optical registration. Results of experiments testify that the phenomenon is reproduced both for SEP, and for Comp. B. Focusing process is observed in conditions close to critical conditions of transfer of a detonation from active to a passive HE charge.

  19. Biological Denitrification of High Nitrate Processing Wastewaters from Explosives Production Plant.

    PubMed

    Cyplik, Paweł; Marecik, Roman; Piotrowska-Cyplik, Agnieszka; Olejnik, Anna; Drożdżyńska, Agnieszka; Chrzanowski, Lukasz

    2012-05-01

    Wastewater samples originating from an explosives production plant (3,000 mg N l(-1) nitrate, 4.8 mg l(-1) nitroglycerin, 1.9 mg l(-1) nitroglycol and 1,200 mg l(-1) chemical oxygen demand) were subjected to biological purification. An attempt to completely remove nitrate and to decrease the chemical oxygen demand was carried out under anaerobic conditions. A soil isolated microbial consortium capable of biodegrading various organic compounds and reduce nitrate to atmospheric nitrogen under anaerobic conditions was used. Complete removal of nitrates with simultaneous elimination of nitroglycerin and ethylene glycol dinitrate (nitroglycol) was achieved as a result of the conducted research. Specific nitrate reduction rate was estimated at 12.3 mg N g(-1) VSS h(-1). Toxicity of wastewater samples during the denitrification process was studied by measuring the activity of dehydrogenases in the activated sludge. Mutagenicity was determined by employing the Ames test. The maximum mutagenic activity did not exceed 0.5. The obtained results suggest that the studied wastewater samples did not exhibit mutagenic properties. PMID:22593607

  20. High power laser coupling to carbon nano-tubes and ion Coulomb explosion

    SciTech Connect

    K, Magesh Kumar K; Tripathi, V. K.

    2013-09-15

    Linear and non linear interaction of laser with an array of carbon nanotubes is investigated. The ac conductivity of nanotubes, due to uneven response of free electrons in them to axial and transverse fields, is a tensor. The propagation constant for p-polarization shows resonance at a specific frequency that varies with the direction of laser propagation. It also shows surface plasmon resonance at ω=ω{sub p}/√(2), where ω{sub p} is the plasma frequency of free electrons inside a nanotube, assumed to be uniform plasma cylinder. The attenuation constant is also resonantly enhanced around these frequencies. At large laser amplitude, the nanotubes behave as thin plasma rods. As the electrons get heated, the nanotubes undergo hydrodynamic expansion. At an instant when plasma frequency reaches ω{sub p}=√(2)ω, the electron temperature rises rapidly and then saturates. For a Gaussian laser beam, the heating rate is maximum on the laser axis and falls off with the distance r from the axis. When the excursion of the electrons Δ is comparable or larger than the radius of the nanotube r{sub c}, the nanotubes undergo ion Coulomb explosion. The distribution function of ions turns out to be a monotonically decreasing function of energy.

  1. Highly sensitive standoff detection and identification of traces of explosives and of biological and chemical agents

    NASA Astrophysics Data System (ADS)

    Portnov, Alexander; Bar, Illana; Rosenwaks, Salman

    2010-10-01

    Our experiments focused on monitoring the signal obtained from diffuse reflections of forward-generated coherent anti-Stokes Raman scattering (CARS), occurring in different samples, referred to as "backward-CARS" (B-CARS). The methodology of B-CARS was developed and the feasibility of using it as a spectroscopic tool for standoff detection of particles of explosives and related compounds studied. Signals of both the B-CARS and spontaneous Raman scattering under similar conditions were monitored to compare their sensitivities. In addition, the dependence of the B-CARS signal on the distance was measured at short ranges and the standoff detection capabilities of the method at long distances estimated. The measurements imply that B-CARS allows favorable detection as compared to Raman. However, an inherent drawback of the developed narrowband B-CARS method is the need to scan the Stokes beam frequency to monitor the different vibrational levels of the detected species. We therefore embarked on a broadband B-CARS method (patent pending) which is based on the application of a sub-ns ultra-broadband laser source for the Stokes beam and enables to monitor simultaneously a wide span of vibrational transitions of the detected species.

  2. High-explosive properties from classical molecular dynamics simulations and quantum-chemical computations

    SciTech Connect

    Sewell, T. D.; Gan, C. K.; Jaramillo, E.; Strachan, A. H.

    2004-01-01

    We are using classical molecular dynamics and condensed phase electronic-structure methods to predict some of the thermophysical and mechanical properties that are needed as input to realistic mesoscale models for plastic-bonded explosives. The main materials studied to date are HMX, PETN, Estane copolymer, and bi(2,2-dinitropropyl) formal/acetal (BDNPF/A). Emphasis is placed on non-reactive properties and thermodynamic states relevant to cookoff and shock initiation phenomena. Both crystal and liquid-state properties are of interest. Typical simulation sizes and times are {approx}10{sup 2} molecules and 2-10 ns, respectively. The overarching goal is to develop internally consistent model thermodynamic and elastic mechanical descriptions for the materials. Prioritization among the set of properties amenable to atomistic simulation is made based on ongoing interactions with mesoscale modelers at Los Alamos and elsewhere. Recent work will be summarized and our view of profitable directions for future research will be discussed, including preliminary results for large-scale molecular dynamics simulations of shock response of crystalline HMX.

  3. High power laser coupling to carbon nano-tubes and ion Coulomb explosion

    NASA Astrophysics Data System (ADS)

    K, Magesh Kumar K.; Tripathi, V. K.

    2013-09-01

    Linear and non linear interaction of laser with an array of carbon nanotubes is investigated. The ac conductivity of nanotubes, due to uneven response of free electrons in them to axial and transverse fields, is a tensor. The propagation constant for p-polarization shows resonance at a specific frequency that varies with the direction of laser propagation. It also shows surface plasmon resonance at ω =ωp/√2 , where ωp is the plasma frequency of free electrons inside a nanotube, assumed to be uniform plasma cylinder. The attenuation constant is also resonantly enhanced around these frequencies. At large laser amplitude, the nanotubes behave as thin plasma rods. As the electrons get heated, the nanotubes undergo hydrodynamic expansion. At an instant when plasma frequency reaches ωp=√2 ω, the electron temperature rises rapidly and then saturates. For a Gaussian laser beam, the heating rate is maximum on the laser axis and falls off with the distance r from the axis. When the excursion of the electrons Δ is comparable or larger than the radius of the nanotube rc, the nanotubes undergo ion Coulomb explosion. The distribution function of ions turns out to be a monotonically decreasing function of energy.

  4. High-temperature vitrification of Hanford residual-liquid waste in a continuous melter

    SciTech Connect

    Barnes, S.M.

    1980-04-01

    Over 270 kg of high-temperature borosilicate glass have been produced in a series of three short-term tests in the High-Temperature Ceramic Melter vitrification system at PNL. The glass produced was formulated to vitrify simulated Hanford residual-liquid waste. The tests were designed to (1) demonstrate the feasibility of utilizing high-temperature, continuous-vitrification technology for the immobilization of the residual-liquid waste, (2) test the airlift draining technique utilized by the high-temperature melter, (3) compare glass produced in this process to residual-liquid glass produced under laboratory conditions, (4) investigate cesium volatility from the melter during waste processing, and (5) determine the maximum residual-liquid glass production rate in the high-temperature melter. The three tests with the residual-liquid composition confirmed the viability of the continuous-melting vitrification technique for the immobilization of this waste. The airlift draining technique was demonstrated in these tests and the glass produced from the melter was shown to be less porous than the laboratory-produced glass. The final glass produced from the second test was compared to a glass of the same composition produced under laboratory conditions. The comparative tests found the glasses to be indistinguishable, as the small differences in the test results fell within the precision range of the characterization testing equipment. The cesium volatility was examined in the final test. This examination showed that 0.44 wt % of the cesium (assumed to be cesium oxide) was volatilized, which translates to a volatilization rate of 115 mg/cm/sup 2/-h.

  5. High throughput secondary electron imaging of organic residues on a graphene surface

    PubMed Central

    Zhou, Yangbo; O'Connell, Robert; Maguire, Pierce; Zhang, Hongzhou

    2014-01-01

    Surface organic residues inhibit the extraordinary electronic properties of graphene, hindering the development of graphene electronics. However, fundamental understanding of the residue morphology is still absent due to a lack of high-throughput and high-resolution surface characterization methods. Here, we demonstrate that secondary electron (SE) imaging in the scanning electron microscope (SEM) and helium ion microscope (HIM) can provide sub-nanometer information of a graphene surface and reveal the morphology of surface contaminants. Nanoscale polymethyl methacrylate (PMMA) residues are visible in the SE imaging, but their contrast, i.e. the apparent lateral dimension, varies with the imaging conditions. We have demonstrated a quantitative approach to readily obtain the physical size of the surface features regardless of the contrast variation. The fidelity of SE imaging is ultimately determined by the probe size of the primary beam. HIM is thus evaluated to be a superior SE imaging technique in terms of surface sensitivity and image fidelity. A highly efficient method to reveal the residues on a graphene surface has therefore been established. PMID:25391356

  6. [Peculiarities of forensic medical reconstruction of the mechanism of injuries in numerous victims of the explosion of a high-capacity blasting device].

    PubMed

    Fradkina, N A; Kovalev, A V; Makarov, I Iu

    2013-01-01

    The systemic analysis of forensic medical practice in Moscow during the past 15 years has demonstrated the scientific, practical, and social significance of expertise of peace-time blast injuries resulting from many terrorist attacks with the use of improvised high-capacity explosive devices that caused multiple human victims. The authors emphasize the current lack of objective forensic medical criteria for the reconstruction of the mechanism of injuries in numerous victims of the explosion of a high-capacity blasting device. It dictates the necessity of their development and substantiation of their practical application. PMID:23802296

  7. Converting biowaste corncob residue into high value added porous carbon for supercapacitor electrodes.

    PubMed

    Qu, Wen-Hui; Xu, Yuan-Yuan; Lu, An-Hui; Zhang, Xiang-Qian; Li, Wen-Cui

    2015-08-01

    In this report, corncob residue, the main by-product in the furfural industry, is used as a precursor to prepare porous carbon by a simple and direct thermal treatment: one-step activation without pre-carbonization. As a consequence, the corncob residue derived porous carbon achieves a high surface area of 1210 m(2) g(-1) after ash-removal. The carbon material has the advantages of low cost and low environmental impact, with a superior electrochemical performance compared to those polymer-based synthetic carbons as electrode material for a supercapacitor. The carbon electrode exhibits a high capacitance of 314 F g(-1) in 6M KOH electrolyte. The corresponding sample also shows a superb cycling stability. Almost no capacitance decay was observed after 100,000 cycles. The excellent electrochemical performance is due to the combination of a high specific surface area with a fraction of mesopores and highly stable structure. PMID:25898091

  8. Closure plan for the decommissioned high explosives rinse-water lagoons at Lawrence Livermore National Laboratory Site 300

    SciTech Connect

    Carpenter, D.W.; Lamarre, A.L.; Crow, N.B.; Swearengen, P.M.

    1988-05-31

    The High Explosives (HE) Process Area is a major facility at Lawrence Livermore National Laboratory (LLNL) Site 300. Within the Process Area, rinse water from various buildings formerly was discharged to nine relatively small, unlined lagoons where it was disposed of by evaporation and infiltration. In 1985, LLNL decommissioned these lagoons and diverted the rinse waters to two doubly lined surface impoundments. LLNL conducted the hydrogeologic investigations required to support the permanent closure of the none decommissioned lagoons. These studies included drilling ground water monitoring wells and extensively collecting soil and rock samples, which were analyzed for EPA toxic metals, HE compounds, and purgeable and extractable priority organic pollutants. On October 26, 1987, the RWQCB requested that we prepare a comprehensive report to summarize and discuss the findings of the LLNL HE Process Area Investigation. This report is our response to the Board's request. 22 refs., 19 figs. , 45 tabs.

  9. Safety Considerations for Laser Power on Metals in Contact with High Explosives-Experimental an Calculational Results

    SciTech Connect

    Roeske, F.; Carpenter, K. H.

    2000-04-19

    Measurements have been made to determine safe levels of laser exposure on common metals used in contact with high explosive (HE) samples. Laser light is often used on metals in contact with HE during alignment procedures and experimental data collection. The measurements look at temperature rise of the surface of the metal in contact with HE when laser energy is incident on the opposite side of the metal. The temperature rise was measured as a function of incident laser power, spot size, metal composition and metal thickness. Numerical simulations were also performed to solve the two-dimensional heat flow problem for the experimental geometry. In order to allow a single numerical simulation to represent a large number of physical cases, the equations used in the simulation were expressed in terms of dimensionless variables. The normalized numerical solutions can then be compared with the various experimental configurations used. Calculations and experiment agree well over the range measured.

  10. PHETS (Permanent High Explosive Test Site) lightning hardening program: Misty Picture Event. Final report, January-November 1987

    SciTech Connect

    Chapman, G.P.; Gardner, R.L.; Lu, G.S.; Rison, W.; Gurbaxani, S.H.

    1988-06-01

    The Permanent High Explosive Test Site (PHETS) test-bed electrical topology and data flow are presented along with various equipments used in the topology. Using this information, recommendations are made to harden the test-bed instrumentation to electrical transients. These transients may be caused by lightning or electrostatic discharge. Specific attention is given to the junction box design, the shorting blocks, use of shielded cables, protection of the sensors, and the instrumentation bunker/container. Additional attention is given to the protection of personnel from lightning effects. Also, it is recommended the optimum design is of a Faraday-cage concept that completely encases the instrumentation from sensor to permanent recording medium. The optimum design should be prototyped and tested using the Precision Test bed and current injection before general application to the PHETS.

  11. A Comparison of Neutron-Based Non-Destructive Assessment Methods for Chemical Warfare Material and High Explosives

    SciTech Connect

    Seabury, E. H.; Chichester, D. L.; Wharton, C. J.; Caffrey, A. J.

    2009-03-10

    Prompt Gamma Neutron Activation Analysis (PGNAA) systems employ neutrons as a probe to interrogate items, e.g. chemical warfare materiel-filled munitions. The choice of a neutron source in field-portable systems is determined by its ability to excite nuclei of interest, operational concerns such as radiological safety and ease-of-use, and cost. Idaho National Laboratory's PINS Chemical Assay System has traditionally used a {sup 252}Cf isotopic neutron source, but recently a deuterium-tritium (DT) electronic neutron generator (ENG) has been tested as an alternate neutron source. This paper presents the results of using both of these neutron sources to interrogate chemical warfare materiel (CWM) and high explosive (HE) filled munitions.

  12. A Comparison of Neutron-Based Non-Destructive Assessment Methods for Chemical Warfare Materiel and High Explosives

    SciTech Connect

    E.H. Seabury; D.L. Chichester; C.J. Wharton; A.J. Caffrey

    2008-08-01

    Prompt Gamma Neutron Activation Analysis (PGNAA) systems employ neutrons as a probe to interrogate items, e.g. chemical warfare materiel-filled munitions. The choice of a neutron source in field-portable systems is determined by its ability to excite nuclei of interest, operational concerns such as radiological safety and ease-of-use, and cost. Idaho National Laboratory’s PINS Chemical Assay System has traditionally used a Cf-252 isotopic neutron source, but recently a Deuterium-Tritium (DT) Electronic Neutron Generator (ENG) has been tested as an alternate neutron source. This paper presents the results of using both of these neutron sources to interrogate chemical warfare materiel (CWM) and high explosive (HE) filled munitions.

  13. A Comparison of Neutron-Based Non-Destructive Assessment Methods for Chemical Warfare Materiel and High Explosives

    NASA Astrophysics Data System (ADS)

    Seabury, E. H.; Chichester, D. L.; Wharton, C. J.; Caffrey, A. J.

    2009-03-01

    Prompt Gamma Neutron Activation Analysis (PGNAA) systems employ neutrons as a probe to interrogate items, e.g. chemical warfare materiel-filled munitions. The choice of a neutron source in field-portable systems is determined by its ability to excite nuclei of interest, operational concerns such as radiological safety and ease-of-use, and cost. Idaho National Laboratory's PINS Chemical Assay System has traditionally used a 252Cf isotopic neutron source, but recently a deuterium-tritium (DT) electronic neutron generator (ENG) has been tested as an alternate neutron source. This paper presents the results of using both of these neutron sources to interrogate chemical warfare materiel (CWM) and high explosive (HE) filled munitions.

  14. Report on the suitability of Class 6, U.S. government security repositories for the storage of small quantities of high explosives

    SciTech Connect

    Harry, H.H.; Murk, D.

    1998-03-01

    The Explosives Review Committee initiated a study into the safety aspects of the common practice of storing small amounts (< 10 grams per drawer) of high explosives in safes. Although storage of HE in older asbestos lined safes was permitted, the newer style Class 6 Security safes are an unacceptable repository for even very small amounts of HE without the use of a blast mitigating insert. The authors have developed a drawer liner in the form of a laminated Lexan, foam, plywood box that will withstand the blast and contain the fragments from up to 10 grams of high explosives. This liner will fit into the drawer of any existing safe. The liner will provide blast and fragment protection, and the safe will provide security protection. This report describes the testing of modern safes and the performance of the liner insert.

  15. Environmental Assessment for the High Explosives Wastewater Treatment Facility, Los Alamos National Laboratory, Los Alamos, New Mexico

    SciTech Connect

    1995-08-03

    The Department of Energy (DOE) has identified a need to improve the management of wastewater resulting from high explosives (HE) research and development work at Los Alamos National Laboratory (LANL). LANL`s current methods off managing HE-contaminated wastewater cannot ensure that discharged HE wastewater would consistently meet the Environmental Protection Agency`s (EPA`s) standards for wastewater discharge. The DOE needs to enhance He wastewater management to e able to meet both present and future regulatory standards for wastewater discharge. The DOE also proposes to incorporate major pollution prevention and waste reduction features into LANL`s existing HE production facilities. Currently, wastewater from HE processing buildings at four Technical Areas (TAs) accumulates in sumps where particulate HE settles out and barium is precipitated. Wastewater is then released from the sumps to the environment at 15 permitted outfalls without treatment. The released water may contain suspended and dissolved contaminants, such as HE and solvents. This Environmental Assessment (EA) analyzes two alternatives, the Proposed Action and the Alternative Action, that would meet the purpose and need for agency action. Both alternatives would treat all HE process wastewater using sand filters to remove HE particulates and activated carbon to adsorb organic solvents and dissolved HE. Under either alternative, LANL would burn solvents and flash dried HE particulates and spent carbon following well-established procedures. Burning would produce secondary waste that would be stored, treated, and disposed of at TA-54, Area J. This report contains the Environmental Assessment, as well as the Finding of No Significant Impact and Floodplain Statement of Findings for the High Explosives Wastewater Treatment Facility.

  16. Abiotic transformation of high explosives by freshly precipitated iron minerals in aqueous Fe¹¹ solutions

    SciTech Connect

    Boparai, Hardiljeet K.; Comfort, Steve; Satapanajaru, Tunlawit; Szecsody, James E.; Grossl, Paul; Shea, Patrick

    2010-05-11

    Zerovalent iron barriers have become a viable treatment for field-scale cleanup of various ground water contaminants. While contact with the iron surface is important for contaminant destruction, the interstitial pore water within and near the iron barrier will be laden with aqueous, adsorbed and precipitated FeII phases. These freshly precipitated iron minerals could play an important role in transforming high explosives (HE). Our objective was to determine the transformation of RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine), HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine), and TNT (2,4,6-trinitrotoluene) by freshly precipitated iron FeII/FeIII minerals. This was accomplished by quantifying the effects of initial FeII concentration, pH, and the presence of aquifer solids (FeIII phases) on HE transformation rates. Results showed that at pH 8.2, freshly precipitated iron minerals transformed RDX, HMX, and TNT with reaction rates increasing with increasing FeII concentrations. RDX and HMX transformations in these solutions also increased with increasing pH (5.8-8.55). By contrast, TNT transformation was not influenced by pH (6.85-8.55) except at pH values <6.35. Transformations observed via LC/MS included a variety of nitroso products (RDX, HMX) and amino degradation products (TNT). XRD analysis identified green rust and magnetite as the dominant iron solid phases that precipitated from the aqueous FeII during HE treatment under anaerobic conditions. Geochemical modeling also predicted FeII activity would likely be controlled by green rust and magnetite. These results illustrate the important role freshly precipitated FeII/FeIII minerals in aqueous FeII solutions play in the transformation of high explosives.

  17. Explosive cord

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Device, jetcord, is metal-clad linear explosive of sufficient flexibility to allow forming into intricate shapes. Total effect is termed ''cutting'' with jetcord consistently ''cutting'' a target of greater thickness than can be penetrated. Applications include sheet metal working, pipe cutting and fire-fighting.

  18. Human immunodeficiency virus type 1 integrase: effect on viral replication of mutations at highly conserved residues.

    PubMed

    Cannon, P M; Wilson, W; Byles, E; Kingsman, S M; Kingsman, A J

    1994-08-01

    Sequence comparisons of the integrase (IN) proteins from different retroviruses have identified several highly conserved residues. We have introduced mutations at 16 of these sites into the integrase gene of human immunodeficiency virus type 1 and analyzed the phenotypes of the resulting viruses. The viruses were all normal for p24 content and reverse transcriptase activity. In addition, all of the mutants could infect T-cell lines and undergo reverse transcription, as assessed by PCR analysis. Most of the mutant viruses also had normal Western blot (immunoblot) profiles, although three of the mutations resulted in reduced signals for IN relative to the wild type on the immunoblots and mutation of residue W235 completely abolished recognition of the protein by pooled sera from human immunodeficiency virus type 1-positive patients. Mutations that have previously been shown to abolish activity in in vitro studies produced noninfectious viruses. The substitution of W235 was notable in producing a noninfectious virus, despite previous reports of this residue being nonessential for IN activity in vitro (A.D. Leavitt, L. Shiue, and H.E. Varmus, J. Biol. Chem. 268:2113-2119, 1993). In addition, we have identified four highly conserved residues that can be mutated without any affect on viral replication in T-cell lines. PMID:8035478

  19. Partial alignment and measurement of residual dipolar couplings of proteins under high hydrostatic pressure

    PubMed Central

    Fu, Yinan; Wand, A. Joshua

    2013-01-01

    High-pressure NMR spectroscopy has emerged as a complementary approach for investigating various structural and thermodynamic properties of macromolecules. Noticeably absent from the array of experimental restraints that have been employed to characterize protein structures at high hydrostatic pressure is the residual dipolar coupling, which requires the partial alignment of the macromolecule of interest. Here we examine five alignment media that are commonly used at ambient pressure for this purpose. We find that the spontaneous alignment of Pf1 phage, d(GpG) and a C12E5/n-hexnanol mixture in a magnetic field is preserved under high hydrostatic pressure. However, DMPC/ DHPC bicelles and collagen gel are found to be unsuitable. Evidence is presented to demonstrate that pressure-induced structural changes can be identified using the residual dipolar coupling. PMID:23807390

  20. Sunset Crater, AZ: Evolution of a highly explosive basaltic eruption as indicated by granulometry and clast componentry

    NASA Astrophysics Data System (ADS)

    Allison, C. M.; Clarke, A. B.; Pioli, L.; Alfano, F.

    2011-12-01

    Basaltic scoria cone volcanoes are the most abundant volcanic edifice on Earth and occur in all tectonic settings. Basaltic magmas have lower viscosities, higher temperatures, and lower volatile contents than silicic magmas, and therefore generally have a lower potential for explosive activity. However, basaltic eruptions display great variability in eruptive style, from mild lava flows to more energetic explosions with large plumes. The San Francisco Volcanic Field (SFVF) in northern Arizona, active from 6 Ma-present, consists of over 600 volcanoes, mostly alkali basalt scoria cones, and five silicic centers [Wood and Kienle (1990), Cambridge University Press]. The eruption of Sunset Crater in the SFVF during the Holocene was an anomalously large basaltic explosive eruption, consisting of eight tephra-bearing phases and three lava flows [Amos (1986), MS thesis, ASU]. Typical scoria cone-forming eruptions have volumes <0.1km3 DRE, while the Sunset Crater deposit is at least 0.6km3 DRE [Amos (1986)]. The phases vary in size and style; the beginning stages of explosive activity (phases 1-2) were considerably smaller than phases 3-5, classified as subplinian. Due to its young age, the eruptive material is fresh and the deposit is well-preserved. We sampled the first five tephra units at 25 locations, ranging from 6 km to 20 km from the vent, concentrating our efforts in the downwind direction (E and SE of the vent) along the primary dispersal axes of several phases. Notable variations among the first five phases were found from evaluation of juvenile clast componentry, with each phase containing some proportion of red, grey, and glassy to iridescent clasts. The red and grey clasts are sub-rounded to rounded with high sphericity, while the other clasts are highly angular and slightly elongate, with blue-black to gold glassy and iridescent surfaces. The glassy and iridescent clasts likely represent fresh, juvenile ejecta, which were quenched rapidly, whereas the red and

  1. TOWARD END-TO-END MODELING FOR NUCLEAR EXPLOSION MONITORING: SIMULATION OF UNDERGROUND NUCLEAR EXPLOSIONS AND EARTHQUAKES USING HYDRODYNAMIC AND ANELASTIC SIMULATIONS, HIGH-PERFORMANCE COMPUTING AND THREE-DIMENSIONAL EARTH MODELS

    SciTech Connect

    Rodgers, A; Vorobiev, O; Petersson, A; Sjogreen, B

    2009-07-06

    This paper describes new research being performed to improve understanding of seismic waves generated by underground nuclear explosions (UNE) by using full waveform simulation, high-performance computing and three-dimensional (3D) earth models. The goal of this effort is to develop an end-to-end modeling capability to cover the range of wave propagation required for nuclear explosion monitoring (NEM) from the buried nuclear device to the seismic sensor. The goal of this work is to improve understanding of the physical basis and prediction capabilities of seismic observables for NEM including source and path-propagation effects. We are pursuing research along three main thrusts. Firstly, we are modeling the non-linear hydrodynamic response of geologic materials to underground explosions in order to better understand how source emplacement conditions impact the seismic waves that emerge from the source region and are ultimately observed hundreds or thousands of kilometers away. Empirical evidence shows that the amplitudes and frequency content of seismic waves at all distances are strongly impacted by the physical properties of the source region (e.g. density, strength, porosity). To model the near-source shock-wave motions of an UNE, we use GEODYN, an Eulerian Godunov (finite volume) code incorporating thermodynamically consistent non-linear constitutive relations, including cavity formation, yielding, porous compaction, tensile failure, bulking and damage. In order to propagate motions to seismic distances we are developing a one-way coupling method to pass motions to WPP (a Cartesian anelastic finite difference code). Preliminary investigations of UNE's in canonical materials (granite, tuff and alluvium) confirm that emplacement conditions have a strong effect on seismic amplitudes and the generation of shear waves. Specifically, we find that motions from an explosion in high-strength, low-porosity granite have high compressional wave amplitudes and weak shear

  2. Visualization of explosion phenomena using a high-speed video camera with an uncoupled objective lens by fiber-optic

    NASA Astrophysics Data System (ADS)

    Tokuoka, Nobuyuki; Miyoshi, Hitoshi; Kusano, Hideaki; Hata, Hidehiro; Hiroe, Tetsuyuki; Fujiwara, Kazuhito; Yasushi, Kondo

    2008-11-01

    Visualization of explosion phenomena is very important and essential to evaluate the performance of explosive effects. The phenomena, however, generate blast waves and fragments from cases. We must protect our visualizing equipment from any form of impact. In the tests described here, the front lens was separated from the camera head by means of a fiber-optic cable in order to be able to use the camera, a Shimadzu Hypervision HPV-1, for tests in severe blast environment, including the filming of explosions. It was possible to obtain clear images of the explosion that were not inferior to the images taken by the camera with the lens directly coupled to the camera head. It could be confirmed that this system is very useful for the visualization of dangerous events, e.g., at an explosion site, and for visualizations at angles that would be unachievable under normal circumstances.

  3. [High-dose chemotherapy and residual tumor resection in male germ cell tumors].

    PubMed

    Lorch, A; Albers, P; Winter, C; Beyer, J

    2011-09-01

    As a consequence of the unsatisfactory results of conventional dose salvage regimens, in particular for patients with poor prognostic features at the time of relapse or in patients with refractory disease, high-dose chemotherapy (HDCT) was introduced into clinical practice in the late 1980s. The combination of carboplatin and etoposide (CE) still remains the backbone of most high-dose regimens. Multiple modifications with more dose escalations or addition of further drugs have been explored, most often with increased toxicity. With improved expertise in supportive care and the use of peripheral blood stem cells, hematopoetic recovery has been significantly shortened and the initial high treatment-related mortality reduced from more than 10% to about 3%. Since the incorporation of HDCT, even patients with unfavorable prognostic features or patients with second or subsequent relapses can achieve long-term remission. Following HDCT residual tumor resection plays a major role in achieving these long-term results. The proportion of vital residual tumor after HDCT is much higher than in patients after conventional chemotherapy. The role of HDCT remains controversial particularly as a first-line treatment and less so in the first salvage setting. As these patients are rare HDCT and residual tumor resection should only be be provided by high-volume centers with sufficient expertise in performing these complex procedures. PMID:21845425

  4. Raman and photothermal spectroscopies for explosive detection

    NASA Astrophysics Data System (ADS)

    Finot, Eric; Brulé, Thibault; Rai, Padmnabh; Griffart, Aurélien; Bouhélier, Alexandre; Thundat, Thomas

    2013-06-01

    Detection of explosive residues using portable devices for locating landmine and terrorist weapons must sat- isfy the application criteria of high reproducibility, specificity, sensitivity and fast response time. Vibrational spectroscopies such as Raman and infrared spectroscopies have demonstrated their potential to distinguish the members of the chemical family of more than 30 explosive materials. The characteristic chemical fingerprints in the spectra of these explosives stem from the unique bond structure of each compound. However, these spectroscopies, developed in the early sixties, suffer from a poor sensitivity. On the contrary, MEMS-based chemical sensors have shown to have very high sensitivity lowering the detection limit down to less than 1 picogram, (namely 10 part per trillion) using sensor platforms based on microcantilevers, plasmonics, or surface acoustic waves. The minimum amount of molecules that can be detected depends actually on the transducer size. The selectivity in MEMS sensors is usually realized using chemical modification of the active surface. However, the lack of sufficiently selective receptors that can be immobilized on MEMS sensors remains one of the most critical issues. Microcantilever based sensors offer an excellent opportunity to combine both the infrared photothermal spectroscopy in their static mode and the unique mass sensitivity in their dynamic mode. Optical sensors based on localized plasmon resonance can also take up the challenge of addressing the selectivity by monitoring the Surface Enhanced Raman spectrum down to few molecules. The operating conditions of these promising localized spectroscopies will be discussed in terms of reliability, compactness, data analysis and potential for mass deployment.

  5. Micellar electrokinetic chromatography of organic and peroxide-based explosives.

    PubMed

    Johns, Cameron; Hutchinson, Joseph P; Guijt, Rosanne M; Hilder, Emily F; Haddad, Paul R; Macka, Mirek; Nesterenko, Pavel N; Gaudry, Adam J; Dicinoski, Greg W; Breadmore, Michael C

    2015-05-30

    CE methods have been developed for the analysis of organic and peroxide-based explosives. These methods have been developed for deployment on portable, in-field instrumentation for rapid screening. Both classes of compounds are neutral and were separated using micellar electrokinetic chromatography (MEKC). The effects of sample composition, separation temperature, and background electrolyte composition were investigated. The optimised separation conditions (25 mM sodium tetraborate, 75 mM sodium dodecyl sulfate at 25°C, detection at 200 nm) were applied to the separation of 25 organic explosives in 17 min, with very high efficiency (typically greater than 300,000 plates m(-1)) and high sensitivity (LOD typically less than 0.5 mg L(-1); around 1-1.5 μM). A MEKC method was also developed for peroxide-based explosives (10 mM sodium tetraborate, 100 mM sodium dodecyl sulfate at 25°C, detection at 200 nm). UV detection provided LODs between 5.5 and 45.0 mg L(-1) (or 31.2-304 μM), which is comparable to results achieved using liquid chromatography. Importantly, no sample pre-treatment or post-column reaction was necessary and the peroxide-based explosives were not decomposed to hydrogen peroxide. Both MEKC methods have been applied to pre-blast analysis and for the detection of post-blast residues recovered from controlled, small scale detonations of organic and peroxide-based explosive devices. PMID:25998463

  6. Measurement of residual stresses on ceramic materials with high spatial resolution

    SciTech Connect

    Kozaczek, K.J.; Ruud, C.O.; Fitting, J.D.

    1993-12-31

    A fast x-ray diffraction technique has been developed for measuring the residual stresses with high spatial resolution in ceramic materials. This resolution is limited by the mean size of grains and the radiation type. The effective diffraction elastic constants were experimentally determined for alumina as (E/l+{nu})){sub (1016)} = 200 GPa. The accuracy of XRD measurement of residual stresses with the spatial resolution of 170 {mu}m and precision {plus_minus} 15 MPa was verified experimentally by strain gauge measurements. The stress field around a singular Kovar pin brazed to alumina was asymmetric with high tangential stresses in the vicinity of the pin decreasing with the distance from the pin.

  7. Explosion containment device

    DOEpatents

    Benedick, William B.; Daniel, Charles J.

    1977-01-01

    The disclosure relates to an explosives storage container for absorbing and containing the blast, fragments and detonation products from a possible detonation of a contained explosive. The container comprises a layer of distended material having sufficient thickness to convert a portion of the kinetic energy of the explosion into thermal energy therein. A continuous wall of steel sufficiently thick to absorb most of the remaining kinetic energy by stretching and expanding, thereby reducing the momentum of detonation products and high velocity fragments, surrounds the layer of distended material. A crushable layer surrounds the continuous steel wall and accommodates the stretching and expanding thereof, transmitting a moderate load to the outer enclosure. These layers reduce the forces of the explosion and the momentum of the products thereof to zero. The outer enclosure comprises a continuous pressure wall enclosing all of the layers. In one embodiment, detonation of the contained explosive causes the outer enclosure to expand which indicates to a visual observer that a detonation has occurred.

  8. Determination of nitroxynil residues in tissues using high-performance liquid chromatography-thermospray mass spectrometry.

    PubMed

    Blanchflower, W J; Kennedy, D G

    1989-09-01

    A method is described for the determination of nitroxynil residues in muscle, liver and kidney. The samples were extracted into diethyl ether and cleaned-up using a simple liquid-liquid extraction step. Any nitroxynil present was separated from interfering compounds by high-performance liquid chromatography and detected using thermospray mass spectrometry. The assay is specific and sensitive, with a detection limit of 2 ng g-1 in tissues. PMID:2610364

  9. The Interaction of Explosively Generated Plasma with Explosives

    NASA Astrophysics Data System (ADS)

    Tasker, Douglas; LANL Team

    2015-06-01

    It has been shown that the temperature of explosively generated plasma (EGP) is of the order of 1 eV and plasma ejecta can be focused to achieve velocities as high as 25 km/s. These high velocity plasma can readily penetrate a wide range of materials including metals. Proof-of-principle tests were performed to determine if EGP could be used for explosive ordnance demolition and other applications. The test goals were: to benignly disable ordnance containing relatively sensitive high performance explosives (PBX-9501); and to investigate the possibility of interrupting an ongoing detonation in a powerful high explosive (again PBX-9501) with EGP. Experiments were performed to establish the optimum sizes of plasma generators for the benign deactivation of high explosives, i.e., the destruction of the ordnance without initiating a detonation or comparable violent event. These experiments were followed by attempts to interrupt an ongoing detonation by the destruction of the unreacted explosive in its path. The results were encouraging. First, it was demonstrated that high explosives could be destroyed without the initiation of a detonation or high order reaction. Second, ongoing detonations were successfully interrupted with EGP. LA-UR-15-20612.

  10. Explosive Joining

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Laurence J. Bement of Langley Research Center invented a technique to permit metal joining operations under hazardous or inaccessible conditions. The process, which provides a joint with double the strength of the parent metal, involves the use of very small quantities of ribbon explosive to create hermetically sealed joints. When the metal plates are slammed together by the explosion's force, joining is accomplished. The collision causes a skin deep melt and ejection of oxide films on the surfaces, allowing a linkup of electrons that produce superstrong, uniform joints. The technique can be used to join metals that otherwise would not join and offers advantages over mechanical fasteners and adhesives. With Langley assistance, Demex International Ltd. refined and commercialized the technology. Applications include plugging leaking tubes in feedwater heaters. Demex produces the small plugs, associated sleeves and detonators. The technology allows faster plugging, reduces downtime, cuts plugging costs and increases reliability.

  11. Demonstration Explosion

    NASA Astrophysics Data System (ADS)

    Lee, Charles "Skip"

    1998-05-01

    Last week I did a demonstration that produced a serious explosion. After putting methanol in a big glass carboy and rotating the carboy to build up some methanol vapor, I lit the mouth of the carboy. What normally happens is a "jet engine" effect out of the mouth of the carboy. In my case, the carboy exploded. Two polycarbonate blast shields were shattered and glass was blown as far as 15 feet away. I was not seriously cut and bruised, but had I not been using the two blast shields, I would have been severely injured. At this time, I am not sure what caused the explosion. I have done this demonstration around one hundred times with no problem using the exact same amount of methanol and technique. I think it is important to get the word out that this demonstration may be more dangerous than previously thought. I would also welcome any hypotheses concerning what caused the carboy to explode.

  12. Minimizing high spatial frequency residual error in active space telescope mirrors

    NASA Astrophysics Data System (ADS)

    Gray, Thomas L.; Smith, Matthew W.; Cohan, Lucy E.; Miller, David W.

    2009-08-01

    The trend in future space telescopes is towards larger apertures, which provide increased sensitivity and improved angular resolution. Lightweight, segmented, rib-stiffened, actively controlled primary mirrors are an enabling technology, permitting large aperture telescopes to meet the mass and volume restrictions imposed by launch vehicles. Such mirrors, however, are limited in the extent to which their discrete surface-parallel electrostrictive actuators can command global prescription changes. Inevitably some amount of high spatial frequency residual error is added to the wavefront due to the discrete nature of the actuators. A parameterized finite element mirror model is used to simulate this phenomenon and determine designs that mitigate high spatial frequency residual errors in the mirror surface figure. Two predominant residual components are considered: dimpling induced by embedded actuators and print-through induced by facesheet polishing. A gradient descent algorithm is combined with the parameterized mirror model to allow rapid trade space navigation and optimization of the mirror design, yielding advanced design heuristics formulated in terms of minimum machinable rib thickness. These relationships produce mirrors that satisfy manufacturing constraints and minimize uncorrectable high spatial frequency error.

  13. Brontides: natural explosive noises.

    PubMed

    Gold, T; Soter, S

    1979-04-27

    Episodes of explosive noises of natural origin, or brontides, have been well documented, often in association with seismic activity and in a few cases as precursors to major earthquakes. Ground-to-air acoustic transmission from shallow earthquakes can account for many of these episodes, but not for all, and other causes, such as the sudden eruption of gas from high-pressure sources in the ground may at times have been responsible. Confusion with distant thunder or artillery at times of anomalous sound propagation complicates the analysis, and more recently the greatly increased frequency of artificial explosive noises and sonic booms has tended to mask the recognition of natural brontides. PMID:17757998

  14. Destruction of peroxide explosives.

    PubMed

    Oxley, Jimmie C; Smith, James L; Huang, Jiaorong; Luo, Wei

    2009-09-01

    Chemicals containing multiple peroxide functionalities, such as triacetone triperoxide (TATP), diacetone diperoxide (DADP), or hexamethylene triperoxide diamine (HMTD), can be explosive. They are impractical and are not used by legitimate military groups because they are shock and heat sensitive compared to military explosives. They are attractive to terrorists because synthesis is straightforward, requiring only a few easily obtained ingredients. Physical removal of these synthesis products is highly hazardous. This paper discusses methods to degrade peroxide explosives chemically, at room temperature. A number of mixtures containing metals (e.g., zinc, copper) and metal salts (e.g., zinc sulfate, copper chloride) were found effective, some capable of destroying TATP solutions in a few hours. Strong acids proved useful against solid peroxide materials; however, on a 1 g scale, addition of concentrated sulfuric acid caused TATP to detonate. Thus, this technique should only be used to destroy small-laboratory quantities. PMID:19737243

  15. Effect of electrode force condition on nugget diameter and residual stress in resistance spot welded high-strength steel sheets

    NASA Astrophysics Data System (ADS)

    Iyota, M.; Mikami, Y.; Hashimoto, T.; Taniguchi, K.; Ikeda, R.; Mochizuki, M.

    2012-08-01

    This study examines the effect of the electrode force condition on the nugget diameter and residual stress in spot welded high-strength steel sheets. Numerical simulations of spot welding were performed to examine the nugget diameter and residual stress. The results indicate that adjusting the force profile changes the current density and stress state at the spot welds. Therefore, choosing an appropriate force profile extends the nugget diameter and reduces the residual stress.

  16. Trace Explosive Detection Using Nanosensors

    SciTech Connect

    Senesac, Larry R; Thundat, Thomas George

    2008-01-01

    Selective and sensitive detection of explosives is very important in countering terrorist threats. Detecting trace explosives has become a very complex and expensive endeavor because of a number of factors, such as the wide variety of materials that can be used as explosives, the lack of easily detectable signatures, the vast number of avenues by which these weapons can be deployed, and the lack of inexpensive sensors with high sensitivity and selectivity. High sensitivity and selectivity, combined with the ability to lower the deployment cost of sensors using mass production, is essential in winning the war on explosives-based terrorism. Nanosensors have the potential to satisfy all the requirements for an effective platform for the trace detection of explosives.

  17. Residue-free fabrication of high-performance graphene devices by patterned PMMA stencil mask

    SciTech Connect

    Shih, Fu-Yu; Chen, Shao-Yu; Wu, Tsuei-Shin; Wang, Wei-Hua; Liu, Cheng-Hua; Chen, Yang-Fang; Ho, Po-Hsun; Chen, Chun-Wei

    2014-06-15

    Two-dimensional (2D) atomic crystals and their hybrid structures have recently attracted much attention due to their potential applications. The fabrication of metallic contacts or nanostructures on 2D materials is very common and generally achieved by performing electron-beam (e-beam) lithography. However, e-beam lithography is not applicable in certain situations, e.g., cases in which the e-beam resist does not adhere to the substrates or the intrinsic properties of the 2D materials are greatly altered and degraded. Here, we present a residue-free approach for fabricating high-performance graphene devices by patterning a thin film of e-beam resist as a stencil mask. This technique can be generally applied to substrates with varying surface conditions, while causing negligible residues on graphene. The technique also preserves the design flexibility offered by e-beam lithography and therefore allows us to fabricate multi-probe metallic contacts. The graphene field-effect transistors fabricated by this method exhibit smooth surfaces, high mobility, and distinct magnetotransport properties, confirming the advantages and versatility of the presented residue-free technique for the fabrication of devices composed of 2D materials.

  18. Residue-free fabrication of high-performance graphene devices by patterned PMMA stencil mask

    NASA Astrophysics Data System (ADS)

    Shih, Fu-Yu; Chen, Shao-Yu; Liu, Cheng-Hua; Ho, Po-Hsun; Wu, Tsuei-Shin; Chen, Chun-Wei; Chen, Yang-Fang; Wang, Wei-Hua

    2014-06-01

    Two-dimensional (2D) atomic crystals and their hybrid structures have recently attracted much attention due to their potential applications. The fabrication of metallic contacts or nanostructures on 2D materials is very common and generally achieved by performing electron-beam (e-beam) lithography. However, e-beam lithography is not applicable in certain situations, e.g., cases in which the e-beam resist does not adhere to the substrates or the intrinsic properties of the 2D materials are greatly altered and degraded. Here, we present a residue-free approach for fabricating high-performance graphene devices by patterning a thin film of e-beam resist as a stencil mask. This technique can be generally applied to substrates with varying surface conditions, while causing negligible residues on graphene. The technique also preserves the design flexibility offered by e-beam lithography and therefore allows us to fabricate multi-probe metallic contacts. The graphene field-effect transistors fabricated by this method exhibit smooth surfaces, high mobility, and distinct magnetotransport properties, confirming the advantages and versatility of the presented residue-free technique for the fabrication of devices composed of 2D materials.

  19. Highly sensitive homogeneous electrochemical aptasensor for antibiotic residues detection based on dual recycling amplification strategy.

    PubMed

    Wang, Xiuzhong; Dong, Shanshan; Gai, Panpan; Duan, Rui; Li, Feng

    2016-08-15

    The ubiquitous presence of antibiotic residues in foodstuff have serious health consequences for consumers from allergic reactions to the evolution of antibiotic-resistant bacteria. To address this problem, a novel homogeneous electrochemical aptasensor with high sensitivity and specificity is designed for antibiotic residues detection based on target-induced and T7 exonuclease-assisted dual recycling signal amplification strategy. It was realized by the remarkable diffusivity difference between hairpin probe and the mononucleotides towards the negatively charged indium tin oxide electrode. For the proof-of-concept experiment, ampicillin, was employed as a model analyte to examine the desirable properties of this assay. A low detection limit of 4.0pM toward ampicillin with an excellent selectivity could be achieved, which has been successfully applied to assay antibiotic in milk. What's more, compared with the immobilization-based electrochemical means, the proposed sensing system avoids the tedious and time-consuming steps of electrode modification, making the experimental processes much simpler and more convenient. With the advantages of high sensitivity, excellent selectivity and simple operation, it is believed that this strategy possesses great potential for the simple, easy and convenient detection of antibiotic residues in food safety field. PMID:27040941

  20. Determination of tylosin residues in pig tissues using high-performance liquid chromatography.

    PubMed

    De Liguoro, M; Anfossi, P; Angeletti, R; Montesissa, C

    1998-06-01

    In accordance with the maximum residue limit of 100 micrograms kg-1 established by EU legislation, a simple and sensitive high-performance liquid chromatographic (HPLC) method was developed for the measurement of tylosin residues in pig tissues (fat, kidney, liver and muscle). Tylosin, a macrolide antibiotic, is extracted with water-methanol and cleaned-up by solid-phase extraction (SPE) on cation-exchange cartridges using methanol elution. Tylosin was determined by reversed-phase HPLC with UV detection at 280 nm and the mean recovery from pig tissues fortified in the range 50-200 micrograms kg-1 was 70-85%, with intra- and inter-day RSDs in the ranges 3.4-9.1 and 3.9-10.1% respectively. PMID:9764508

  1. Spectroscopic Measurement of High-Frequency Electric Fields in the Interaction of Explosive Debris Plasma with Ambient, Magnetized Background Plasma

    NASA Astrophysics Data System (ADS)

    Bondarenko, Anton; Schaeffer, Derek; Everson, Erik; Clark, Eric; Vincena, Stephen; van Compernolle, Bart; Tripathi, Shreekrishna; Constantin, Carmen; Niemann, Chris

    2014-10-01

    The explosive expansion of dense, high-beta debris plasma into relatively tenuous, magnetized background plasma is relevant to a wide variety of astrophysical and space environments. Electric fields play a fundamental role in the coupling of momentum and energy from debris to background, and emission spectroscopy provides a powerful diagnostic for assessing electric fields via the Stark effect. A recent experiment utilizing a unique experimental platform at UCLA that combines the Large Plasma Device and the Raptor laser facility has investigated the super-Alfvénic, quasi-perpendicular expansion of a laser-produced carbon (C) debris plasma through a preformed, ambient, magnetized helium (He) background plasma via emission spectroscopy. Spectral profiles of the He II 468.6 nm line have been analyzed via single-mode and multi-mode time-dependent Stark broadening models for hydrogen-like ions, yielding large magnitude (~100 kV/cm), high-frequency (~100 GHz) electric fields. The measurements suggest the development of an electron beam-plasma instability, and a simple instability saturation model demonstrates that the measured electric field magnitudes are feasible under the experimental conditions.

  2. Explosive simulants for testing explosive detection systems

    DOEpatents

    Kury, John W.; Anderson, Brian L.

    1999-09-28

    Explosives simulants that include non-explosive components are disclosed that facilitate testing of equipment designed to remotely detect explosives. The simulants are non-explosive, non-hazardous materials that can be safely handled without any significant precautions. The simulants imitate real explosives in terms of mass density, effective atomic number, x-ray transmission properties, and physical form, including moldable plastics and emulsions/gels.

  3. Method for fabricating non-detonable explosive simulants

    DOEpatents

    Simpson, Randall L.; Pruneda, Cesar O.

    1995-01-01

    A simulator which is chemically equivalent to an explosive, but is not detonable. The simulator has particular use in the training of explosives detecting dogs and calibrating sensitive analytical instruments. The explosive simulants may be fabricated by different techniques, a first involves the use of standard slurry coatings to produce a material with a very high binder to explosive ratio without masking the explosive vapor, and the second involves coating inert beads with thin layers of explosive molecules.

  4. Method for fabricating non-detonable explosive simulants

    DOEpatents

    Simpson, R.L.; Pruneda, C.O.

    1995-05-09

    A simulator is disclosed which is chemically equivalent to an explosive, but is not detonable. The simulator has particular use in the training of explosives detecting dogs and calibrating sensitive analytical instruments. The explosive simulants may be fabricated by different techniques, a first involves the use of standard slurry coatings to produce a material with a very high binder to explosive ratio without masking the explosive vapor, and the second involves coating inert beads with thin layers of explosive molecules. 5 figs.

  5. Analysis of Picattiny Sample for Trace Explosives

    SciTech Connect

    Klunder, G; Whipple, R; Carman, L; Spackman, P E; Reynolds, J; Alcaraz, A

    2008-05-23

    The sample received from Picatinny Arsenal was analyzed for trace amounts of high explosives (HE). A complete wash of the surface was performed, concentrated, and analyzed using two sensitive analysis techniques that are capable of detecting numerous types of explosives. No explosives were detected with either test.

  6. Thermally stable, plastic-bonded explosives

    DOEpatents

    Benziger, Theodore M.

    1979-01-01

    By use of an appropriate thermoplastic rubber as the binder, the thermal stability and thermal stress characteristics of plastic-bonded explosives may be greatly improved. In particular, an HMX-based explosive composition using an oil-extended styrene-ethylenebutylene-styrene block copolymer as the binder exhibits high explosive energy and thermal stability and good handling safety and physical properties.

  7. Doping explosive materials for neutron radiographic enhancement.

    NASA Technical Reports Server (NTRS)

    Golliher, K. G.

    1971-01-01

    Discussion of studies relating to the selection of doping materials of high neutron absorption usable for enhancing the neutron radiographic imaging of explosive mixtures, without interfering with the proper chemical reaction of the explosives. The results of the studies show that gadolinium oxide is an excellent material for doping explosive mixtures to enhance the neutron radiographic image.

  8. Characterization of laboratory analogs of interstellar/cometary organic residues using very high resolution mass spectrometry

    NASA Astrophysics Data System (ADS)

    Danger, G.; Orthous-Daunay, F.-R.; de Marcellus, P.; Modica, P.; Vuitton, V.; Duvernay, F.; Flandinet, L.; Le Sergeant d'Hendecourt, L.; Thissen, R.; Chiavassa, T.

    2013-10-01

    Studying the chemical composition of organic matter in astrophysical environments is an important means to improve our understanding of its origin and evolution. This organic matter evolves from molecular clouds to protoplanetary disks, and as a final destination, takes part in the formation of many objects of our solar system, such as primitive chondritic material, planetesimals and finally planets. In this contribution, we perform experimental simulations based on the VUV irradiation and warming-up of primitive interstellar ice analogs (CH3OH:NH3:H2O), and characterize, for the first time, the resulting refractory residue, using very high resolution mass spectrometry (VHRMS) with an LTQ-orbitrap-XL instrument. An electrospray source allows ionizing all the molecules having proton donor or acceptor chemical functions, while limiting as much as possible their damages. Thus, this method provides the analysis of the whole ionizable molecules making up the residue. The analysis of the spectra shows that these residues contain a large number of molecules formed of CHNO elements, including macromolecular entities beyond 4000 Da. The average elemental composition of the residue is of H/C = 1.5, N/C = 0.4, O/C = 0.4. These first results are tentatively compared to VHRMS analyses of the soluble organic matter (SOM) present in the Murchison’s meteorite, a primitive chondrite of the CM class. The molecular richness observed can be considered as the “first step” of the complex abiotic organic matter in extraterrestrial media. This initial matter, that may be rather universal, could then evolve toward more processed materials in parent bodies, such as comets and asteroids, materials that are then observed and subsequently analyzed in meteorites found on Earth. In addition to providing some insight on the mixture complexity, VHRMS allows for the search of specific molecules. For instance, hexamethylenetetramine (HMT) and some of its derivatives are identified in these

  9. High Residue Winter Cover Crops Deplete Winter Annual Weed Seed Across a Landscape in a Long-Term Tillage Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High residue conservation agriculture systems have the potential to maximize environmental benefits achieved when practicing reduced tillage. A greenhouse study was conducted in 2006 through 2008 to determine the effects of cover crop residue on weed seed density within the soil seedbank under varyi...

  10. What factors control the superficial lava dome explosivity?

    NASA Astrophysics Data System (ADS)

    Boudon, Georges; Balcone-Boissard, Hélène; Villemant, Benoit; Morgan, Daniel J.

    2015-04-01

    Dome-forming eruption is a frequent eruptive style; lava domes result from intermittent, slow extrusion of viscous lava. Most dome-forming eruptions produce highly microcrystallized and highly- to almost totally-degassed magmas which have a low explosive potential. During lava dome growth, recurrent collapses of unstable parts are the main destructive process of the lava dome, generating concentrated pyroclastic density currents (C-PDC) channelized in valleys. These C-PDC have a high, but localized, damage potential that largely depends on the collapsed volume. Sometimes, a dilute ash cloud surge develops at the top of the concentrated flow with an increased destructive effect because it may overflow ridges and affect larger areas. In some cases, large lava dome collapses can induce a depressurization of the magma within the conduit, leading to vulcanian explosions. By contrast, violent, laterally directed, explosions may occur at the base of a growing lava dome: this activity generates dilute and turbulent, highly-destructive, pyroclastic density currents (D-PDC), with a high velocity and propagation poorly dependent on the topography. Numerous studies on lava dome behaviors exist, but the triggering of lava dome explosions is poorly understood. Here, seven dome-forming eruptions are investigated: in the Lesser Antilles arc: Montagne Pelée, Martinique (1902-1905, 1929-1932 and 650 y. BP eruptions), Soufrière Hills, Montserrat; in Guatemala, Santiaguito (1929 eruption); in La Chaîne des Puys, France (Puy de Dome and Puy Chopine eruptions). We propose a new model of superficial lava-dome explosivity based upon a textural and geochemical study (vesicularity, microcrystallinity, cristobalite distribution, residual water contents, crystal transit times) of clasts produced by these key eruptions. Superficial explosion of a growing lava dome may be promoted through porosity reduction caused by both vesicle flattening due to gas escape and syn-eruptive cristobalite

  11. Morphologically manipulated Ag/ZnO nanostructures as surface enhanced Raman scattering probes for explosives detection

    NASA Astrophysics Data System (ADS)

    Shaik, Ummar Pasha; Hamad, Syed; Ahamad Mohiddon, Md.; Soma, Venugopal Rao; Ghanashyam Krishna, M.

    2016-03-01

    The detection of secondary explosive molecules (e.g., ANTA, FOX-7, and CL-20) using Ag decorated ZnO nanostructures as surface enhanced Raman scattering (SERS) probes is demonstrated. ZnO nanostructures were grown on borosilicate glass substrates by rapid thermal oxidation of metallic Zn films at 500 °C. The oxide nanostructures, including nanosheets and nanowires, emerged over the surface of the Zn film leaving behind the metal residue. We demonstrate that SERS measurements with concentrations as low as 10 μM, of the three explosive molecules ANTA, FOX-7, and CL-20 over ZnO/Ag nanostructures, resulted in enhancement factors of ˜107, ˜107, and ˜104, respectively. These measurements validate the high sensitivity of detection of explosive molecules using Ag decorated ZnO nanostructures as SERS substrates. The Zn metal residue and conditions of annealing play an important role in determining the detection sensitivity.

  12. Dynamics of the detonation products of a TATB based high explosive: Photon doppler velocimetry and high-speed digital shadowgraphy of expanding species

    NASA Astrophysics Data System (ADS)

    Sollier, Arnaud; Bouyer, Viviane; Terzulli, Louis-Pierre; Doucet, Michel; Hebert, Philippe; Decaris, Lionel

    2012-03-01

    We have performed time-resolved free surface velocity measurements of the expanding products from the detonation of a TATB based high explosive composition, using both Heterodyne Velocimetry (i.e. Photon Doppler Velocimetry) and digital high speed shadowgraphy. The free surface velocity waveforms exhibit features which can be directly related to charateristics of the reaction zone. This allows to estimate the von Neumann spike pressure to PVN ≃41 GPa and the duration of the reaction zone to 400-500 ns, in good agreement with previous studies. 2D Eulerian direct numerical simulations performed with the wide-ranging equation of state and reaction rate model developed by Wescott, Scott Stewart and Davis are found to be in very good agreement with our experimental results.

  13. Optical detection of explosives: spectral signatures for the explosive bouquet

    NASA Astrophysics Data System (ADS)

    Osborn, Tabetha; Kaimal, Sindhu; Causey, Jason; Burns, William; Reeve, Scott

    2009-05-01

    Research with canines suggests that sniffer dogs alert not on the odor from a pure explosive, but rather on a set of far more volatile species present in an explosive as impurities. Following the explosive trained canine example, we have begun examining the vapor signatures for many of these volatile impurities utilizing high resolution spectroscopic techniques in several molecular fingerprint regions. Here we will describe some of these high resolution measurements and discuss strategies for selecting useful spectral signature regions for individual molecular markers of interest.

  14. In-situ monitoring of flow-permeable surface area of high explosive powder using small sample masses

    SciTech Connect

    Maiti, Amitesh; Han, Yong; Zaka, Fowzia; Gee, Richard H.

    2015-02-17

    To ensure good performance of high explosive devices over long periods of time, initiating powders need to maintain their specific surface area within allowed margins during the entire duration of deployment. A common diagnostic used in this context is the Fisher sub-sieve surface area (FSSA). Furthermore, commercial permeametry instruments measuring the FSSA requires the utilization of a sample mass equal to the crystal density of the sample material, an amount that is often one or two orders of magnitude larger than the typical masses found in standard detonator applications. Here we develop a customization of the standard device that can utilize just tens of milligram samples, and with simple calibration yield FSSA values at ac curacy levels comparable to the standard apparatus. This necessitated a newly designed sample holder, made from a material of low coefficient of thermal expansion, which is conveniently transferred between an aging chamber and a re-designed permeametry tube. This improves the fidelity of accelerated aging studies by allowing measurement on the same physical sample at various time - instants during the aging process, and by obviating the need for a potentially FSSA-altering powder re-compaction step. We used the customized apparatus to monitor the FSSA evolution of a number of undoped and homolog-doped PETN powder samples that were subjected to artificial aging for several months at elevated temperatures. These results, in conjunction with an Arrhenius-based aging model were used to assess powder-coarsening - rates under long-term storage.

  15. An explosive outbreak of Streptococcus pneumoniae serotype-8 infection in a highly vaccinated residential care home, England, summer 2012.

    PubMed

    Thomas, H L; Gajraj, R; Slack, M P E; Sheppard, C; Hawkey, P; Gossain, S; Drew, C M; Pebody, R G

    2015-07-01

    In August 2012, an explosive outbreak of severe lower respiratory tract infection (LRTI) due to Streptococcus pneumoniae serotype-8 occurred in a highly vaccinated elderly institutionalized population in England. Fifteen of 23 residents developed LRTI over 4 days (attack rate 65%); 11 had confirmed S. pneumoniae serotype-8 disease, and two died. Following amoxicillin chemoprophylaxis and pneumococcal polysaccharide vaccine (PPV) re-vaccination no further cases occurred in the following 2 months. No association was found between being an outbreak-associated case and age (P = 0.36), underlying comorbidities [relative risk (RR) 0.84 95% confidence interval (CI) 0.34-2.09], or prior receipt of PPV (RR 1.4, 95% CI 0.60-3.33). However, the median number of years since PPV was significantly higher for cases (n = 15, 10.2 years, range 7.3-17.9 years) than non-cases (n = 8, 7.2 years, range 6.8-12.8 years) (P = 0.045), provided evidence of waning immunity. Alternative vaccination strategies should be considered to prevent future S. pneumoniae outbreaks in institutionalized elderly populations. PMID:25298247

  16. A Method of Highly Sensitive Detecting of Explosives on the Basis of FAIMS Analyzer with Laser Ion Source

    NASA Astrophysics Data System (ADS)

    Chistyakov, A. A.; Kotkovskii, G. E.; Odulo, I. P.; Spitsyn, E. M.; Shestakov, A. V.

    In this work comparison of the desorption effectiveness of picosecond and nanosecond laser sources (λ=266, 532 nm) were carried out to investigate the possibility of creating a non-contact sampling device for detectors of explosives on the principles of ion mobility spectrometry (IMS) and field asymmetric ion mobility spectrometry (FAIMS). The results of mass spectrometric studies of TNT (2,4,6-Trinitrotoluene), HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine), RDX (1,3,5-Trinitro-1,3,5-triazacyclohexane) laser desorption from a quartz substrate are presented. It is shown that the most effective laser source is a Nd:YAG3+ laser (λ = 266 nm; E = 1 mJ; τ = 5-10 ns; q = 108 W/cm2). The typical desorbed mass is 2 ng for RDX, 4-6 ng for TNT and 0.02 ng HMX per single laser pulse. The results obtained make it possible to create a non-contact portable laser sampling device operating in frequency mode with high efficiency.

  17. A flow integrated DSD hydrodynamics strategy for computing the motion of detonation of insensitive high explosives on an Eulerian grid

    SciTech Connect

    Short, Mark; Aslam, Tariq D

    2010-01-01

    The detonation structure in many insensitive high explosives consists of two temporally disparate zones of heat release. In PBX 9502, there is a fast reaction zone ({approx} 25 ns) during which reactants are converted to gaseous products and small carbon clusters, followed by a slower regime ({approx} 250 ns) of carbon coagulation. A hybrid approach for determining the propagation of two-stage heat release detonations has been developed that utilizes a detonation shock dynamics (DSD) based strategy for the fast reaction zone with a direct hydrodynamic simulation of the flow in the slow zone. Unlike a standard DSD/programmed bum formulation, the evolution of the fast zone DSD-like surface is coupled to the flow in the slow reaction zone. We have termed this formulation flow integrated detonation shock dynamics (FIDSD). The purpose of the present paper is to show how the FIDSD formulation can be applied to detonation propagation on an Eulerian grid using an algorithm based on level set interface tracking and a ghost fluid approach.

  18. Investigation of heat transfer in high-capacity power transformers having modifications preventing explosions

    NASA Astrophysics Data System (ADS)

    Aksenov, A. A.; Zhluktov, S. V.; Kudimov, N. F.; Son, E. E.; Savitskii, D. V.; Tretiyakova, O. N.; Shishaeva, A. S.

    2014-12-01

    Results of numerical simulation of complex conjugate heat transfer in a high power electric transformer are presented. Simulation of the flow and heat transfer inside a transformer with static blast protection was carried out. Analysis of test calculations performed in the FlowVision software suit was carried out. Comparison of the performance of created numerical model against the real experimental data from the thermal tests of the transformer was made.

  19. Prompt detonation of secondary explosives by laser

    SciTech Connect

    Paisley, D.L.

    1989-01-01

    Secondary high explosives have been promptly detonated by directing a laser beam of various wavelengths from 266 nanometers to 1.06 micron on the surface of the explosives. For this paper ''prompt'' means the excess transit time through an explosive charge is /approximately/250 nanoseconds (or less) less than the accepted full detonation velocity time. Timing between laser pulse, explosive initiation and detonation velocity and function time have been recorded. The laser parameters studied include: wavelength, pulse length, energy and power density, and beam diameter (spot size). Explosives evaluated include: PETN, HNS, HMX, and graphited PETN, HNS, and HMX. Explosive parameters that have been correlated with optical parameters include: density, surface area, critical diameter (spot size), spectral characteristics and enhance absorption. Some explosives have been promptly detonated over the entire range of wavelengths, possibly by two competing initiating mechanisms. Other explosives could not be detonated at any of the wavelengths or power densities tested. 8 refs., 12 figs., 1 tab.

  20. Detonation wave profiles in HMX based explosives

    SciTech Connect

    Gustavsen, R.L.; Sheffield, S.A.; Alcon, R.R.

    1997-11-01

    Detonation wave profiles have been measured in several HMX based plastic bonded explosives including PBX9404, PBX9501, and EDC-37, as well as two HMX powders (coarse and fine) pressed to 65% of crystal density. The powders had 120 and 10 {micro}m average grain sizes, respectively. Planar detonations were produced by impacting the explosive with projectiles launched in a 72-mm bore gas gun. Impactors, impact velocity, and explosive thickness were chosen so that the run distance to detonation was always less than half the explosive thickness. For the high density plastic bonded explosives, particle velocity wave profiles were measured at an explosive/window interface using two VISAR interferometers. PMMA windows with vapor deposited aluminum mirrors were used for all experiments. Wave profiles for the powdered explosives were measured using magnetic particle velocity gauges. Estimates of the reaction zone parameters were obtained from the profiles using Hugoniots of the explosive and window.

  1. Coupled High Speed Imaging and Seismo-Acoustic Recordings of Strombolian Explosions at Etna, July 2014: Implications for Source Processes and Signal Inversions.

    NASA Astrophysics Data System (ADS)

    Taddeucci, J.; Del Bello, E.; Scarlato, P.; Ricci, T.; Andronico, D.; Kueppers, U.; Cannata, A.; Sesterhenn, J.; Spina, L.

    2015-12-01

    Seismic and acoustic surveillance is routinely performed at several persistent activity volcanoes worldwide. However, interpretation of the signals associated with explosive activity is still equivocal, due to both source variability and the intrinsically limited information carried by the waves. Comparison and cross-correlation of the geophysical quantities with other information in general and visual recording in particular is therefore actively sought. At Etna (Italy) in July 2014, short-lived Strombolian explosions ejected bomb- to lapilli-sized, molten pyroclasts at a remarkably repeatable time interval of about two seconds, offering a rare occasion to systematically investigate the seismic and acoustic fields radiated by this common volcanic source. We deployed FAMoUS (FAst, MUltiparametric Setup for the study of explosive activity) at 260 meters from the vents, recording more than 60 explosions in thermal and visible high-speed videos (50 to 500 frames per second) and broadband seismic and acoustic instruments (1 to 10000 Hz for the acoustic and from 0.01 to 30 Hz for the seismic). Analysis of this dataset highlights nonlinear relationships between the exit velocity and mass of ejecta and the amplitude and frequency of the acoustic signals. It also allows comparing different methods to estimate source depth, and to validate existing theory on the coupling of airwaves with ground motion.

  2. NEW GUN CAPABILITY WITH INTERCHANGABLE BARRELS TO INVESTIGATE LOW VELOCITY IMPACT REGIMES AT THE LAWRENCE LIVERMORE NATIONAL LABORATORY HIGH EXPLOSIVES APPLICATIONS FACILITY

    SciTech Connect

    Vandersall, K S; Behn, A; Gresshoff, M; Jr., L F; Chiao, P I

    2009-09-16

    A new gas gun capability is being activated at Lawrence Livermore National Laboratories located in the High Explosives Applications Facility (HEAF). The single stage light gas (dry air, nitrogen, or helium) gun has interchangeable barrels ranging from 25.4 mm to 76.2 mm in diameter with 1.8 meters in length and is being fabricated by Physics Applications, Inc. Because it is being used for safety studies involving explosives, the gun is planned for operation inside a large enclosed firing tank, with typical velocities planned in the range of 10-300 m/s. Three applications planned for this gun include: low velocity impact of detonator or detonator/booster assemblies with various projectile shapes, the Steven Impact test that involves impact initiation of a cased explosive target, and the Taylor impact test using a cylindrical explosive sample impacted onto a rigid anvil for fracture studies of energetic materials. A highlight of the gun features, outline on work in progress for implementing this capability, and discussion of the planned areas of research will be included.

  3. Explosive radiation in high Andean Hypericum—rates of diversification among New World lineages

    PubMed Central

    Nürk, Nicolai M.; Scheriau, Charlotte; Madriñán, Santiago

    2013-01-01

    The páramos, high-elevation Andean grasslands ranging from ca. 2800 m to the snow line, harbor one of the fastest evolving biomes worldwide since their appearance in the northern Andes 3–5 million years (Ma) ago. Hypericum (St. John's wort), with over 65% of its Neotropical species, has a center of diversity in these high Mountain ecosystems. Using nuclear rDNA internal transcribed spacer (ITS) sequences of a broad sample of New World Hypericum species we investigate phylogenetic patterns, estimate divergence times, and provide the first insights into diversification rates within the genus in the Neotropics. Two lineages appear to have independently dispersed into South America around 3.5 Ma ago, one of which has radiated in the páramos (Brathys). We find strong support for the polyphyly of section Trigynobrathys, several species of which group within Brathys, while others are found in temperate lowland South America (Trigynobrathys s.str.). All páramo species of Hypericum group in one clade. Within these páramo Hypericum species enormous phenotypic evolution has taken place (life forms from arborescent to prostrate shrubs) evidently in a short time frame. We hypothesize multiple mechanisms to be responsible for the low differentiation in the ITS region contrary to the high morphological diversity found in Hypericum in the páramos. Amongst these may be ongoing hybridization and incomplete lineage sorting, as well as the putative adaptive radiation, which can explain the contrast between phenotypic diversity and the close phylogenetic relationships. PMID:24062764

  4. Explosive radiation in high Andean Hypericum-rates of diversification among New World lineages.

    PubMed

    Nürk, Nicolai M; Scheriau, Charlotte; Madriñán, Santiago

    2013-01-01

    The páramos, high-elevation Andean grasslands ranging from ca. 2800 m to the snow line, harbor one of the fastest evolving biomes worldwide since their appearance in the northern Andes 3-5 million years (Ma) ago. Hypericum (St. John's wort), with over 65% of its Neotropical species, has a center of diversity in these high Mountain ecosystems. Using nuclear rDNA internal transcribed spacer (ITS) sequences of a broad sample of New World Hypericum species we investigate phylogenetic patterns, estimate divergence times, and provide the first insights into diversification rates within the genus in the Neotropics. Two lineages appear to have independently dispersed into South America around 3.5 Ma ago, one of which has radiated in the páramos (Brathys). We find strong support for the polyphyly of section Trigynobrathys, several species of which group within Brathys, while others are found in temperate lowland South America (Trigynobrathys s.str.). All páramo species of Hypericum group in one clade. Within these páramo Hypericum species enormous phenotypic evolution has taken place (life forms from arborescent to prostrate shrubs) evidently in a short time frame. We hypothesize multiple mechanisms to be responsible for the low differentiation in the ITS region contrary to the high morphological diversity found in Hypericum in the páramos. Amongst these may be ongoing hybridization and incomplete lineage sorting, as well as the putative adaptive radiation, which can explain the contrast between phenotypic diversity and the close phylogenetic relationships. PMID:24062764

  5. High Temperature Residual Properties of Carbon Fiber Composite Sandwich Panel with Pyramidal Truss Cores

    NASA Astrophysics Data System (ADS)

    Liu, Jiayi; Zhou, Zhengong; Wu, Linzhi; Ma, Li; Pan, Shidong

    2013-08-01

    A study on the mechanical property degradation of carbon fiber composite sandwich panel with pyramidal truss cores by high temperature exposure is performed. Analytical formulae for the residual bending strength of composite sandwich panel after thermal exposure are presented for possible competing failure modes. The composite sandwich panels were fabricated from unidirectional carbon/epoxy prepreg, and were exposed to different temperatures for different time. The bending properties of the exposed specimens were measured by three-point bending tests. Then the effect of high temperature exposure on the bending properties and damage mechanism were analyzed. The results have shown that the residual bending strength of composite sandwich panels decreased with increasing exposure temperature and time, which was caused by the degradation of the matrix property and fiber-matrix interface property at high temperature. The effect of thermal exposure on failure mode of composite sandwich panel was observed as well. The measured failure loads showed good agreement with the analytical predictions. It is expected that this study can provide useful information on the design and application of carbon fiber composite sandwich panel at high temperature.

  6. Performance Enhancement of a High Speed Jet Impingement System for Nonvolatile Residue Removal

    NASA Technical Reports Server (NTRS)

    Klausner, James F.; Mei, Renwei; Near, Steve; Stith, Rex

    1996-01-01

    A high speed jet impingement cleaning facility has been developed to study the effectiveness of the nonvolatile residue removal. The facility includes a high pressure air compressor which charges the k-bottles to supply high pressure air, an air heating section to vary the temperature of the high pressure air, an air-water mixing chamber to meter the water flow and generate small size droplets, and a converging- diverging nozzle to deliver the supersonic air-droplet mixture flow to the cleaning surface. To reliably quantify the cleanliness of the surface, a simple procedure for measurement and calibration is developed to relate the amount of the residue on the surface to the relative change in the reflectivity between a clean surface and the greased surface. This calibration procedure is economical, simple, reliable, and robust. a theoretical framework is developed to provide qualitative guidance for the design of the test and interpretation of the experimental results. The result documented in this report support the theoretical considerations.

  7. High-speed imaging of explosive exoemission from an alumina ceramic in vacuum

    NASA Astrophysics Data System (ADS)

    Coaker, B. M.; Xu, N. S.; Jones, F. J.; Latham, R. V.

    1994-05-01

    A fast-video imaging technique was used to observe the pulsed breakdown behavior of an alumina tube, having two concentric planar electrodes on its end-face. Voltage-pulses, typically of 5 kV amplitude (5 kV microsecond(s) -1 time rate-of-rise), were applied to the radial M-I-M insulator-electrode regime under ultra-high vacuum (pressure < 10-8 Torr), with video recordings made at 1000 frames per second. Images of the observed breakdown phenomena are presented, viewing along the center-axis and also in the plane of the M-I-M structure. These images are discussed in relation to plasma-jets associated with vacuum arcs, and the nature of the ion species within such jets.

  8. Dissolution and sorption of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and 2,4,6-trinitrotoluene (TNT) residues from detonated mineral surfaces.

    PubMed

    Jaramillo, Ashley M; Douglas, Thomas A; Walsh, Marianne E; Trainor, Thomas P

    2011-08-01

    Composition B (Comp B) is a commonly used military formulation composed of the toxic explosive compounds 2,4,6-trinitrotoluene (TNT), and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). Numerous studies of the temporal fate of explosive compounds in soils, surface water and laboratory batch reactors have been conducted. However, most of these investigations relied on the application of explosive compounds to the media via aqueous addition and thus these studies do not provide information on the real world loading of explosive residues during detonation events. To address this we investigated the dissolution and sorption of TNT and RDX from Comp B residues loaded to pure mineral phases through controlled detonation. Mineral phases included nontronite, vermiculite, biotite and Ottawa sand (quartz with minor calcite). High Performance Liquid Chromatography and Attenuated Total Reflectance Fourier Transform Infrared spectroscopy were used to investigate the dissolution and sorption of TNT and RDX residues loaded onto the mineral surfaces. Detonation resulted in heterogeneous loading of TNT and RDX onto the mineral surfaces. Explosive compound residues dissolved rapidly (within 9 h) in all samples but maximum concentrations for TNT and RDX were not consistent over time due to precipitation from solution, sorption onto mineral surfaces, and/or chemical reactions between explosive compounds and mineral surfaces. We provide a conceptual model of the physical and chemical processes governing the fate of explosive compound residues in soil minerals controlled by sorption-desorption processes. PMID:21601233

  9. High-throughput multiclass method for antibiotic residue analysis by liquid chromatography-tandem mass spectrometry.

    PubMed

    Chico, J; Rúbies, A; Centrich, F; Companyó, R; Prat, M D; Granados, M

    2008-12-12

    A simple and rapid method has been developed for the residue analysis of 39 antibiotics (tetracyclines, quinolones, penicillins, sulfonamides and macrolides) in foodstuffs of animal origin. The method combines an effective extraction technique, which uses water-methanol as extracting solvent, with ultra-high-pressure liquid chromatography-tandem mass spectrometry, allowing both confirmation and quantification in a single chromatographic run. The multiresidue method has been validated in chicken muscle matrix according to European Union Decision 2002/657/EC. It has been implemented as a routine method in a Public Health Laboratory, instead of the five plates test and LC methods previously used. PMID:18992888

  10. Residual Stress Reversal in Highly Strained Shot Peened Structural Elements. Degree awarded by Florida Univ.

    NASA Technical Reports Server (NTRS)

    Mitchell, William S.; Throckmorton, David (Technical Monitor)

    2002-01-01

    The purpose of this research was to further the understanding of a crack initiation problem in a highly strained pressure containment housing. Finite Element Analysis methods were used to model the behavior of shot peened materials undergoing plastic deformation. Analytical results are in agreement with laboratory tensile tests that simulated the actual housing load conditions. These results further validate the original investigation finding that the shot peened residual stress had reversed, changing from compressive to tensile, and demonstrate that analytical finite element methods can be used to predict this behavior.

  11. Determination of tylosin residues in different animal tissues by high performance liquid chromatography.

    PubMed

    Prats, C; Francesch, R; Arboix, M; Pérez, B

    2002-01-01

    A HPLC method to determine and quantify tylosin residues from calves, pigs and poultry is reported. This procedure permitted tylosin to be separated from muscle, liver, kidney and fat after a simple extraction with chloroform or ethyl acetate under basic conditions. The analytical methodology showed a high specificity and sensitivity and an adequate precision and accuracy with a limit of quantification of 50 microg/kg. Eight calves were administered 20 mg/kg/day of tylosin for 5 days and slaughtered at 7 and 14 days post-administration. Results showed that at the 14th day tylosin levels were lower than the MRL in all target tissues. PMID:11820296

  12. Modeling thermally driven energetic response of high explosives in ALE3D

    SciTech Connect

    Aro, C.; McCallen, R.C.; Neely, R.; Nichols, A.L. III; Sharp, R.

    1998-10-01

    The authors have improved their ability to model the response of energetic materials to thermal stimuli and the processes involved in the energetic response. Traditionally, the analyses of energetic materials have involved coupled thermal transport/chemical reaction codes. This provides only a reasonable estimate of the time and location of ensuing rapid reaction. To predict the violence of the reaction, the mechanical motion must be included in the wide range of time scales associated with the thermal hazard. The ALE3D code has been modified to assess the hazards associated with heating energetic materials in weapons by coupling to thermal transport model and chemistry models. They have developed an implicit time step option to efficiently and accurately compute the hours of heating to reaction of the energetic material. Since, on these longer time scales materials can be expected to have significant motion, it is even more important to provide high-order advection for all components, including the chemical species. They show two examples of coupled thermal/mechanical/chemical models of energetic materials in thermal environments.

  13. Suppression of sludge formation by two-stage hydrocracking of vacuum residue at high conversion

    SciTech Connect

    Mochida, I.; Zhao, X.; Sakanishi, K. )

    1990-12-01

    This paper reports on hydrocracked products from Arabian light vacuum residue at high conversion into distillate ({gt}50%) that were analyzed in order to reveal how sludge formation was suppressed in the two-stage reaction. Although the asphaltene in the starting residue was highly soluble in the starting maltene in spite of is largest molecular weight, single-stage hydrocracking at a higher temperature of 420{degrees}C increased the aromaticity of the asphaltene through extensive deaklylation and dehydrogenation, leading to sludge formation. In contrast, two-stage hydrocracking at 390{degrees}C--3 h/420{degrees}C--1/h accomplished effective depolymerization of the asphaltene, high conversion being achieved without sludge. The carbon aromaticity (f{sub a}) of the produced asphaltene was maintained rather low, although its amount in the product was much the same regardless of the reaction conditions. The heptane-soluble maltenes in the hydrocracked oils exhibited variable dissolving abilities against the asphaltene according to the content and aromaticity of its aromatic fraction, also influencing sludge formation. Hydrocracking produced paraffins through the hydrogenative deaklylation of long-chain alkylbenzenes, decreasing f{sub a} and the dissolving ability of the hydrocracked maltene.

  14. Pretreatment of bamboo by ultra-high pressure explosion with a high-pressure homogenizer for enzymatic hydrolysis and ethanol fermentation.

    PubMed

    Jiang, Zehui; Fei, Benhua; Li, Zhiqiang

    2016-08-01

    Bamboo shoots, 2- and 5-year-old bamboo were treated by using a homogenizer in a constant suspended state, a process termed as ultra-high pressure explosion (UHPE). The bamboo powder was heated in 2% NaOH solution at 121°C, and then 100MPa UHPE-treated through a homogenizer. The results verified that UHPE changed the suspension solution of powder into a stick fluid. The contents of lignin were decreased significantly. The bamboo shoots and 2-year-old bamboo were completely hydrolyzed to glucose within 48h by enzymes loading of 15 FPU of cellulase and 30IU of β-glucosidase per gram glucan. Fermentation of enzymatic hydrolyzates with Saccharomyces cerevisiae resulted in about 89.7-95.1% of the theoretical ethanol yield after 24h. Therefore, NaOH+UHPE is argued to be a potential alternative technology for pretreatment of bamboo. PMID:27189535

  15. The combustion of explosives

    SciTech Connect

    Son, S. F.

    2001-01-01

    The safe use of energetic materials has been scientifically studied for over 100 years. Even with this long history of scientific inquiry, the level of understanding of the important deflagration phenomena in accidental initiations of high explosives remains inadequate to predict the response to possible thermal and mechanical (impact) scenarios. The! search also continues for more well behaved explosives and propellants that perform well, yet are insensitive. Once ignition occurs in an explosive, the question then becomes what the resulting violence will be. The classical view is that simple wave propagation proceeds from the ignition point. Recently, several experiments have elucidated the importance of reactive cracks involved in reaction violence in both thermally ignited experiments and impacted explosives, in contrast to classical assumptions, This work presents a viiw of reaction violence, in both thermal and mechanical insults, that argues for the importance of reactive cracks, rather than simple wave propagation processes. Recent work in this area will be reviewed and presented. Initial results involving novel energetic materials will also be discussed.

  16. Nejapa Tephra: The youngest (c. 1 ka BP) highly explosive hydroclastic eruption in western Managua (Nicaragua)

    NASA Astrophysics Data System (ADS)

    Rausch, Juanita; Schmincke, Hans-Ulrich

    2010-05-01

    Nejapa Maar (2.5 × 1.4 km, c. 120 m deep), the largest maar along the 15-km-long Holocene Nejapa-Miraflores Lineament (NML), is the source vent of the youngest relatively widespread basaltic tholeiitic tephra blanket (Nejapa Tephra: NT) in western central Nicaragua, as shown by isopachs and isopleths (Rausch and Schmincke, 2008). The NT covers an area of > 10 km 2 in W/NW Managua. The minimum total magma volume erupted is estimated as 0.09 km 3. Juvenile, dominantly slightly vesicular (20-40 vol.%) basically tachylitic cauliflower-shaped lapilli with an average density of 2.1 g/cm 3, make up > 90 vol.% of the deposit, while lithoclasts comprise < 10 vol.% except proximally. This, the paucity of fine-grained tuffs and the dominant plane-parallel bedding all suggest fragmentation by shallow interaction of a rising magma starting to vesiculate and fragment pyroclastically with external water. The complex particles so generated erupted in moderately high eruption columns (at least 7-10 km) and were dominantly deposited as dry to damp, warm to cool fallout. Minor surge transport is inferred from fine-grained, locally cross-bedded tephra beds chiefly north of Nejapa and just west of Asososca Maars. Synvolcanic faulting along the NML is inferred. Faults in the study area indicate that activation of the N-S-trending Nejapa-Miraflores Fault (NMF), representing the western flank of Managua Graben, preceded deposition of NT and underlying Masaya Tuff (c.1.8 ka BP), Chiltepe Pumice (c. 1.9 ka BP) and Masaya Triple Layer (2.1 ka BP). The NT deposit is underlain regionally by a paleosol and topped by a soil. The basal paleosol contains pottery sherds made by the Usulután negative technique during the Late Formative period (700 BCE-300 CE) (2.7-1.7 ka BP). The soil overlying NT contains pottery related to the Ometepe technique dated as between 1350 and 1550 CE (650-450 a BP). These, and the radiocarbon dates of the pottery-bearing paleosols (1245 ± 125 and 535 ± 110 a BP

  17. Chaotic explosions

    NASA Astrophysics Data System (ADS)

    Altmann, Eduardo G.; Portela, Jefferson S. E.; Tél, Tamás

    2015-02-01

    We investigate chaotic dynamical systems for which the intensity of trajectories might grow unlimited in time. We show that i) the intensity grows exponentially in time and is distributed spatially according to a fractal measure with an information dimension smaller than that of the phase space, ii) such exploding cases can be described by an operator formalism similar to the one applied to chaotic systems with absorption (decaying intensities), but iii) the invariant quantities characterizing explosion and absorption are typically not directly related to each other, e.g., the decay rate and fractal dimensions of absorbing maps typically differ from the ones computed in the corresponding inverse (exploding) maps. We illustrate our general results through numerical simulation in the cardioid billiard mimicking a lasing optical cavity, and through analytical calculations in the baker map.

  18. Structural changes of high-amylose rice starch residues following in vitro and in vivo digestion.

    PubMed

    Man, Jianmin; Yang, Yang; Zhang, Changquan; Zhou, Xinghua; Dong, Ying; Zhang, Fengmin; Liu, Qiaoquan; Wei, Cunxu

    2012-09-12

    High-amylose cereal starch has a great benefit on human health through its resistant starch content. In this paper, starches were isolated from mature grains of high-amylose transgenic rice line (TRS) and its wild-type rice cultivar Te-qing (TQ) and digested in vitro and in vivo. The structural changes of digestive starch residues were characterized using DSC, XRD, (13)C CP/MAS NMR, and ATR-FTIR. TQ starch was very susceptible to digestion; its residues following in vitro and in vivo digestion showed similar structural characteristics with TQ control starch, which suggested that both amorphous and crystalline structures were simultaneously digested. Both amorphous and the long-range order structures were also simultaneously hydrolyzed in TRS starch, but the short-range order (double helix) structure in the external region of TRS starch granule increased with increasing digestion time. The A-type polymorph of TRS C-type starch was hydrolyzed more rapidly than the B-type polymorph. These results suggested that B-type crystallinity and short-range order structure in the external region of starch granule made TRS starch resistant to digestion. PMID:22917081

  19. Morphology and structural properties of high-amylose rice starch residues hydrolysed by amyloglucosidase.

    PubMed

    Man, Jianmin; Yang, Yang; Huang, Jun; Zhang, Changquan; Zhang, Fengmin; Wang, Youping; Gu, Minghong; Liu, Qiaoquan; Wei, Cunxu

    2013-06-15

    High-amylose starches are attracting considerable attention because of their potential health benefits and industrial uses. Enzyme hydrolysis of starch is involved in many biological and industrial processes. In this paper, starches were isolated from high-amylose transgenic rice (TRS) and its wild type rice, Te-qing (TQ). The morphological and structural changes of starch residues following Aspergillus niger amyloglucosidase (AAG) hydrolysis were investigated. AAG hydrolysed TQ starch from the granule surface, and TRS starch from the granule interior. During AAG hydrolysis, the content of amorphous structure increased, the contents of ordered structure and single helix decreased, and gelatinisation enthalpy decreased in TQ and TRS starch residues. The A-type polymorph of TRS C-type starch was hydrolysed faster than the B-type polymorph. The short-range ordered structure and B-type polymorph in the peripheral region of the subgranule and the surrounding band of TRS starch increased the resistance of TRS starch to AAG hydrolysis. PMID:23497862

  20. On residual gas analysis during high temperature baking of graphite tiles

    NASA Astrophysics Data System (ADS)

    Prakash, A. A.; Chaudhuri, P.; Khirwadkar, S.; Chauhan, N.; Raole, P. M.; Reddy, D. Chenna; Saxena, Y. C.

    2008-05-01

    Steady-state Super-conducting Tokamak-1 (SST-1) is a medium size tokamak with major radius of 1.1 m and minor radius of 0.20 m. It is designed for plasma discharge duration of 1000 seconds to obtain fully steady-state plasma operation. Plasma Facing Components (PFC), consisting of divertors, passive stabilizers, baffles and poloidal limiters are also designed to be UHV compatible for steady state operation. All PFC are made up of graphite tiles mechanically attached to the copper alloy substrate. Graphite is one of the preferred first wall armour material in present day tokamaks. High thermal shock resistance and low atomic number of carbon are the most important properties of graphite for this application. High temperature vacuum baking of graphite tiles is the standard process to remove the impurities. Residual Gas Analyzer (RGA) has been used for qualitative and quantitative measurements of released gases from graphite tiles during baking. Surface Analysis of graphite tiles has also been done before and after baking. This paper describes the residual gas analysis during baking and surface analysis of graphite tiles.

  1. High-Brightness Electron Accelerator Injection System and Experimental Studies of Laser-Induced Explosive Electron Emission.

    NASA Astrophysics Data System (ADS)

    Wang, Xijie

    1992-01-01

    Design studies for the Brookhaven Accelerator Test facility (ATF) injection system are presented. The injection system consists of a high-brightness electron source (photocathode RF gun) and a low-energy transport line. Cavity properties of the RF gun were measured, and found to agree with the calculated results obtained using the computer program SUPERFISH. We also studied the effect of using a non-symmetrical laser spot and RF focusing techniques to reduce the emittance growth in the injection system. A tracking program was developed to investigate higher-order effects on the transverse emittance and the bunch length of the electron beam in the transport line. Field-related electron emissions, i.e., field emission, the Schottky effect in photoemission and field -assisted thermionic emission, were measured. The effect of these electron emissions on the performance of the photocathode RF gun was studied. The possibility of using the momentum of the field emission current for measurement of the RF power in the RF gun was considered. Laser-induced explosive electron emission (EEE) was observed for the first time. It was found that the thresholds of the laser power for RF (80 MV/m) and DC (10 MV/m) cases are 10^9 W/cm ^2 and 10^{11} W/cm^2, respectively. No laser frequency dependence was detected. We infer a 1 muC charge with 20 A average current in RF case, and measured 0.17 muC for the DC situation from laser-induced EEE. The temporal structure of laser-induced EEE was measured. We discussed the possibility of using laser-induced EEE as electron and ion sources.

  2. In-situ monitoring of flow-permeable surface area of high explosive powder using small sample masses

    DOE PAGESBeta

    Maiti, Amitesh; Han, Yong; Zaka, Fowzia; Gee, Richard H.

    2015-02-17

    To ensure good performance of high explosive devices over long periods of time, initiating powders need to maintain their specific surface area within allowed margins during the entire duration of deployment. A common diagnostic used in this context is the Fisher sub-sieve surface area (FSSA). Furthermore, commercial permeametry instruments measuring the FSSA requires the utilization of a sample mass equal to the crystal density of the sample material, an amount that is often one or two orders of magnitude larger than the typical masses found in standard detonator applications. Here we develop a customization of the standard device that canmore » utilize just tens of milligram samples, and with simple calibration yield FSSA values at ac curacy levels comparable to the standard apparatus. This necessitated a newly designed sample holder, made from a material of low coefficient of thermal expansion, which is conveniently transferred between an aging chamber and a re-designed permeametry tube. This improves the fidelity of accelerated aging studies by allowing measurement on the same physical sample at various time - instants during the aging process, and by obviating the need for a potentially FSSA-altering powder re-compaction step. We used the customized apparatus to monitor the FSSA evolution of a number of undoped and homolog-doped PETN powder samples that were subjected to artificial aging for several months at elevated temperatures. These results, in conjunction with an Arrhenius-based aging model were used to assess powder-coarsening - rates under long-term storage.« less

  3. Simultaneous extraction and biotransformation process to obtain high bioactivity phenolic compounds from Brazilian citrus residues.

    PubMed

    Madeira, Jose Valdo; Macedo, Gabriela Alves

    2015-01-01

    Recent studies have pointed to a reduction in the incidence of some cancers, diabetes, and neuro-degenerative diseases as a result of human health benefits from flavanones. Currently, flavanones are obtained by chemical synthesis or extraction from plants, and these processes are only produced in the glycosylated form. An interesting environmentally friendly alternative that deserves attention regarding phenolic compound production is the simultaneous extraction and biotransformation of these molecules. Orange juice consumption has become a worldwide dietary habit and Brazil is the largest producer of orange juice in the world. Approximately half of the citrus fruit is discarded after the juice is processed, thus generating large amounts of residues (peel and pectinolytic material). Hence, finding an environmentally clean technique to extract natural products and bioactive compounds from different plant materials has presented a challenging task over the last decades. The aim of this study was to obtain phenolics from Brazilian citrus residues with high bioactivity, using simultaneous extraction (cellulase and pectinase) and biotransformation (tannase) by enzymatic process. The highest hesperetin, naringenin and ellagic acid production in the experiment were 120, 80, and 11,250 µg g(-1), respectively, at 5.0 U mL(-1) of cellulase and 7.0 U mL(-1) of tannase at 40°C and 200 rpm. Also, the development of this process generated an increase of 77% in the total antioxidant capacity. These results suggest that the bioprocess obtained innovative results where the simultaneous enzymatic and biotransformatic extracted flavanones from agro-industrial residues was achieved without the use of organic solvents. The methodology can therefore be considered a green technology. PMID:26081498

  4. Understanding Magma Storage Conditions that Produce Highly Explosive Monogenetic Basaltic Eruptions Using Olivine-Hosted Melt Inclusions from Sunset Crater, AZ

    NASA Astrophysics Data System (ADS)

    Allison, C. M.; Roggensack, K.; Clarke, A. B.

    2014-12-01

    To investigate mechanisms of explosive basaltic volcanism, we studied the ca. 1085 AD Sunset Crater eruption in the San Francisco Volcanic Field (SFVF) of northern Arizona. This eruption, the youngest in the SFVF, first featured fissure eruptions (explosive phases 1-2) and a small lava flow, and then activity narrowed to a central vent producing explosive phases 3-8 and two additional lava flows. While the first two phases were Strombolian-style explosions, middle phases (3-5) were subplinian in character and produced an anomalously large tephra deposit. The final phases (6-8) are poorly characterized at this stage. The total erupted volume of lava and tephra is >0.7 km3 DRE of alkali olivine basalt with a large proportion of crystal-free glass and low phenocryst content. We studied 82 primary melt inclusions (MIs) in the largest tephra units (explosive phases 3, 4) to investigate magma volatiles and storage conditions. To prioritize primary volatile contents, we picked rapidly quenched free olivine crystals (Fo 81-85; 0.5-2 mm) and selected large volume MIs (50-180 μm) located near crystal cores for analysis. We observed vapor bubbles in all MIs and also noted rare occurrences of CO2-rich gas inclusions. MIs show little major element variability suggesting little crystal fractionation (K2O 0.8-1.1 wt.%). Post-entrapment crystallization is also minor (2-9%). The MI compositions from the two phases largely overlap, with phase 4 skewed to slightly higher K2O. FTIR spectroscopy shows that the MIs are relatively dry and CO2-rich. Water abundances vary 0.8-1.6 wt.% with a median of 1.25 wt.%, while most MIs have CO2 abundances 1,600-3,400 ppm. Phases 3 and 4 are essentially identical in water content. CO2 contents of phases 3 and 4 show considerable overlap, however the phase 4 MIs are skewed toward high CO2 (>2,500 ppm). These results require a minimum MI entrapment depth of ~11 km from fluid saturation constraints. Overall, the MIs indicate a largely homogeneous

  5. Sorption of high explosives to water-dispersible clay: influence of organic carbon, aluminosilicate clay, and extractable iron.

    PubMed

    Dontsova, Katerina M; Hayes, Charolett; Pennington, Judith C; Porter, Beth

    2009-01-01

    Explosives in soils can present environmental problems for military installations. Fine, mobile particles represent the most reactive fraction of the soil and, therefore, are expected to adsorb explosives and potentially facilitate their transport. The objective of this study was to determine the relative significance of phyllosilicate clay, organic matter, and two forms of extractable iron in adsorption of 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by the colloidal water-dispersible clay (WDC) fraction of the soil. The WDC fraction of two mineral and one organic soil was separated and then treated to remove organic carbon (OC) and several forms of iron (Fe(o), oxalate extractable, and Fe(d), dithionite-citrate extractable). Adsorption coefficients were determined for whole soils, untreated, and treated WDC. For mineral soils, adsorption of TNT and RDX on the WDC was greater than on the whole soil. The presence of OC increased explosives sorption by WDC. When OC was removed, iron interfered with TNT sorption. In the presence of OC, removal of Fe(o) decreased RDX adsorption and increased TNT adsorption indicating different adsorption mechanisms. Organic carbon was a more significant indicator of explosives adsorption by WDC than clays or iron oxides and hydroxides. Therefore, OC is the most likely medium for facilitated transport of TNT and RDX. PMID:19465721

  6. Residual Stresses in Inertia-Friction-Welded Dissimilar High-Strength Steels

    NASA Astrophysics Data System (ADS)

    Moat, R. J.; Hughes, D. J.; Steuwer, A.; Iqbal, N.; Preuss, M.; Bray, S. E.; Rawson, M.

    2009-09-01

    The welding of dissimilar alloys is seen increasingly as a way forward to improve efficiencies in modern aeroengines, because it allows one to tailor varying material property demands across a component. Dissimilar inertia friction welding (IFW) of two high-strength steels, Aermet 100 and S/CMV, has been identified as a possible joint for rotating gas turbine components and the resulting welds are investigated in this article. In order to understand the impact of the welding process and predict the life expectancy of such structures, a detailed understanding of the residual stress fields present in the welded component is needed. By combining energy-dispersive synchrotron X-ray diffraction (EDSXRD) and neutron diffraction, it has been possible to map the variations in lattice spacing of the ferritic phase on both sides of two tubular Aermet 100-S/CMV inertia friction welds (as-welded and postweld heat-treated condition) with a wall thickness of 37 mm. Laboratory-based XRD measurements were required to take into account the variation in the strain-free d-spacing across the weld region. It was found that, in the heat-affected zone (HAZ) slightly away from the weld line, residual stress fields showed tensile stresses increasing most dramatically in the hoop direction toward the weld line. Closer to the weld line, in the plastically affected zone, a sharp drop in the residual stresses was observed on both sides, although more dramatically in the S/CMV. In addition to residual stress mapping, synchrotron XRD measurements were carried out to map microstructural changes in thin slices cut from the welds. By studying the diffraction peak asymmetry of the 200- α diffraction peak, it was possible to demonstrate that a martensitic phase transformation in the S/CMV is responsible for the significant stress reduction close to the weld line. The postweld heat treatment (PWHT) chosen to avoid any overaging of the Aermet 100 and to temper the S/CMV martensite resulted in little

  7. Detection of explosives in soils

    DOEpatents

    Chambers, William B.; Rodacy, Philip J.; Phelan, James M.; Woodfin, Ronald L.

    2002-01-01

    An apparatus and method for detecting explosive-indicating compounds in subsurface soil. The apparatus has a probe with an adsorbent material on some portion of its surface that can be placed into soil beneath the ground surface, where the adsorbent material can adsorb at least one explosive-indicating compound. The apparatus additional has the capability to desorb the explosive-indicating compound through heating or solvent extraction. A diagnostic instrument attached to the probe detects the desorbed explosive-indicating compound. In the method for detecting explosive-indicating compounds in soil, the sampling probe with an adsorbent material on at least some portion of a surface of the sampling probe is inserted into the soil to contact the adsorbent material with the soil. The explosive-indicating compounds are then desorbed and transferred as either a liquid or gas sample to a diagnostic tool for analysis. The resulting gas or liquid sample is analyzed using at least one diagnostic tool selected from the group consisting of an ion-mobility spectrometer, a gas chromatograph, a high performance liquid chromatograph, a capillary electrophoresis chromatograph, a mass spectrometer, a Fourier-transform infrared spectrometer and a Raman spectrometer to detect the presence of explosive-indicating compounds.

  8. Shock desensitizing of solid explosives

    SciTech Connect

    Davis, William C

    2010-01-01

    Solid explosive can be desensitized by a shockwave too weak to initiate it promptly, and desensitized explosive does not react although its chemical composition is almost unchanged. A strong second shock does not cause reaction until it overtakes the first shock. The first shock, if it is strong enough, accelerates very slowly at first, and then more rapidly as detonation approaches. These facts suggest that there are two competing reactions. One is the usual explosive goes to products with the release of energy, and the other is explosive goes to dead explosive with no chemical change and no energy release. The first reaction rate is very sensitive to the local state, and the second is only weakly so. At low pressure very little energy is released and the change to dead explosive dominates. At high pressure, quite the other way, most of the explosive goes to products. Numerous experiments in both the initiation and the full detonation regimes are discussed and compared in support of these ideas.

  9. Shock desensitizing of solid explosive

    SciTech Connect

    Davis, William C

    2010-01-01

    Solid explosive can be desensitized by a shock wave too weak to initiate it promptly, and desensitized explosive does not react although its chemical composition is almost unchanged. A strong second shock does not cause reaction until it overtakes the first shock. The first shock, if it is strong enough, accelerates very slowly at first, and then more rapidly as detonation approaches. These facts suggest that there are two competing reactions. One is the usual explosive goes to products with the release of energy, and the other is explosive goes to dead explosive with no chemical change and no energy release. The first reaction rate is very sensitive to the local state, and the second is only weakly so. At low pressure very little energy is released and the change to dead explosive dominates. At high pressure, quite the other way, most of the explosive goes to products. Numerous experiments in both the initiation and the full detonation regimes are discussed and compared in testing these ideas.

  10. Simulating intracrater ash recycling during mid-intensity explosive activity: high temperature laboratory experiments on natural basaltic ash

    NASA Astrophysics Data System (ADS)

    D'Oriano, Claudia; Pompilio, Massimo; Bertagnini, Antonella; Cioni, Raffaello; Pichavant, Michel

    2010-05-01

    Direct observations of mid-intensity eruptions, in which a huge amount of ash is generated, indicate that ash recycling is quite common. The recognition of juvenile vs. recycled fragments is not straightforward, and no unequivocal, widely accepted criteria exist to support this. The presence of recycled glassy fragments can hide primary magmatic information, introducing bias in the interpretations of the ongoing magmatic and volcanic activity. High temperature experiments were performed at atmospheric pressure on natural samples to investigate the effects of reheating on morphology, texture and composition of volcanic ash. Experiments simulate the transformation of juvenile glassy fragments that, falling into the crater or in the upper part of the conduit, are recycled by following explosions. Textural and compositional modifications obtained in laboratory are compared with similar features observed in natural samples in order to identify some main general criteria to be used for the discrimination of recycled material. Experiments were carried out on tephra produced during Strombolian activity, fire fountains and continuous ash emission at Etna, Stromboli and Vesuvius. Coarse glassy clasts were crushed in a nylon mortar in order to create an artificial ash, and then sieved to select the size interval of 1-0.71 mm. Ash shards were put in a sealed or open quartz tube, in order to prevent or to reproduce effects of air oxidation. The tube was suspended in a HT furnace at INGV-Pisa and kept at different temperatures (up to to 1110°C) for increasing time (0.5-12 hours). Preliminary experiments were also performed under gas flux conditions. Optical and electron microscope observations indicate that high temperature and exposure to the air induce large modifications on clast surface, ranging from change in color, to incipient plastic deformation till complete sintering. Significant change in color of clasts is strictly related to the presence of air, irrespective of

  11. Explosive fragmentation of orbiting propellant tanks

    NASA Technical Reports Server (NTRS)

    Benz, F. J.; Kays, R. L.; Bishop, C. V.; Eck, M. B.

    1989-01-01

    An examination is made of the in-orbit explosive characteristics of the Delta second stage and Ariane third stage, with a view to the vehicle breakups of the Ariane SPOT third-stage fuel tank in November, 1986, and of two Delta second stage tanks. Attention is given to the possible role of residual propellants in these breakups. After reviewing orbital data and comparing predicted fragment velocities with observed fragment velocities in debris patterns, a comparison has been made of total debris energy with total calculated explosion energy. Both physical and chemical explosions are deemed possible.

  12. Highly sensitive terahertz spectroscopy of residual pesticide using nano-antenna

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Kyu; Kim, Giyoung; Son, Joo-Hiuk; Seo, Minah

    2016-02-01

    In this report, a novel type of highly sensitive small molecule sensing tool has been employed to detect residual pesticide molecules including e. g. methomyl using terahertz (THz) time-domain spectroscopy (TDS) system with nano-slotantenna array. Enhance THz wave by the nano-slot-antenna array induces strong THz field enhancement around nano antenna and thus increases an absorption cross section leading to the detection sensitivity upto ppm level even in solution state. Measured spectrums in transmission and reflection show an excellent performance in both sensitivity and selectivity. We also tested the performance of our nano-antenna array in reflection imaging geometry to simply detect the contained residual pesticide at the real fruit surface as it is, without any extraction or sampling preprocess. The clear difference in the obtained THz reflection image distinguishes the stained area with methomyl from the bare area. Our observation can offer the possibility for further application as a prompt and an accurate small molecule monitoring tool in real time. A quantitative analysis tool for such small molecule can be also developed by this method.

  13. Analysis of abamectin residues in avocados by high-performance liquid chromatography with fluorescence detection.

    PubMed

    Hernández-Borges, Javier; Ravelo-Pérez, Lidia M; Hernández-Suárez, Estrella M; Carnero, Aurelio; Rodríguez-Delgado, Miguel Angel

    2007-09-21

    In this work an analytical method for the determination of abamectin residues in avocados is developed using high-performance liquid chromatography (HPLC) with fluorescence (FL) detection. A pre-column derivatization with trifluoroacetic anhydride (TFAA) and N-methylimidazole (NMIM) was carried out. The mobile phase consisted of water, methanol and acetonitrile (5:47.5:47.5 v/v/v) and was pumped at a rate of 1 mL/min (isocratic elution). The fluorescence detector was set at an excitation wavelength of 365 nm and an emission wavelength of 470 nm. Homogenized avocado samples were extracted twice with acetonitrile:water 8:2 (v/v) and cleaned using C(18) solid-phase extraction (SPE) cartridges. Recovery values were in the range 87-98% with RSD values lower than 13%. The limits of detection (LODs) and quantification (LOQs) of the whole method were 0.001 and 0.003 mg/kg, respectively. These values are lower than the maximum residue limit (MRL) established by the European Union (EU) and the Spanish legislation in avocado samples. PMID:17681518

  14. Determination of sulphachloropyrazine-diaveridine residues by high performance liquid chromatography in broiler edible tissues.

    PubMed

    Li, Yongjun; Bu, Shijin

    2016-01-01

    Diaveridine (DVD) is used in combination with sulphachloropyrazine (SPZ) as an effective antibacterial agent and antiprotozoal agent, respectively, in humans and animals. To gain a better understanding of the metabolism of SPZ and DVD in the food-producing animals, a high performance liquid chromatography (HPLC) method to determine and quantify sulphachloropyrazine (SPZ) and diaveridine (DVD) suspension residues from broilers is reported. Thirty healthy chickens were orally administered with sulphachloropyrazine-diaveridine (SPZ-DVD) suspension in water of 300 mg/l (SPZ) per day for seven successive days. Six chickens per day were slaughtered at 0, 1, 3, 5 and 7 days after the last administration. This procedure permitted SPZ and DVD to be separated from muscle tissue, liver, kidneys and skin with fat after extraction with acetonitrile and acetone under slightly acidic conditions. From the detected residuals in different tissues, we found that SPZ was quickly eliminated in liver and muscle, and slowly eliminated in kidney and skin with fat. DVD was quickly eliminated in liver and slowly eliminated in kidney. The withdrawal period of SPZ was 3.26, 3.72, 4.39 and 5.43 days in muscle, liver, kidney and skin with fat, respectively. The withdrawal period of DVD was 4.77, 4.94, 6.74 and 4.58 days in muscle, liver, kidney and skin with fat, respectively. Therefore, the suggested withdrawal period for SPZ-DVD suspension should be 7 days after dosing for seven successive days. PMID:26212255

  15. Determination of sulphachloropyrazine-diaveridine residues by high performance liquid chromatography in broiler edible tissues

    PubMed Central

    LI, Yongjun; BU, Shijin

    2015-01-01

    Diaveridine (DVD) is used in combination with sulphachloropyrazine (SPZ) as an effective antibacterial agent and antiprotozoal agent, respectively, in humans and animals. To gain a better understanding of the metabolism of SPZ and DVD in the food-producing animals, a high performance liquid chromatography (HPLC) method to determine and quantify sulphachloropyrazine (SPZ) and diaveridine (DVD) suspension residues from broilers is reported. Thirty healthy chickens were orally administered with sulphachloropyrazine-diaveridine (SPZ-DVD) suspension in water of 300 mg/l (SPZ) per day for seven successive days. Six chickens per day were slaughtered at 0, 1, 3, 5 and 7 days after the last administration. This procedure permitted SPZ and DVD to be separated from muscle tissue, liver, kidneys and skin with fat after extraction with acetonitrile and acetone under slightly acidic conditions. From the detected residuals in different tissues, we found that SPZ was quickly eliminated in liver and muscle, and slowly eliminated in kidney and skin with fat. DVD was quickly eliminated in liver and slowly eliminated in kidney. The withdrawal period of SPZ was 3.26, 3.72, 4.39 and 5.43 days in muscle, liver, kidney and skin with fat, respectively. The withdrawal period of DVD was 4.77, 4.94, 6.74 and 4.58 days in muscle, liver, kidney and skin with fat, respectively. Therefore, the suggested withdrawal period for SPZ-DVD suspension should be 7 days after dosing for seven successive days. PMID:26212255

  16. D-β-aspartyl residue exhibiting uncommon high resistance to spontaneous peptide bond cleavage

    PubMed Central

    Aki, Kenzo; Okamura, Emiko

    2016-01-01

    Although L-amino acids were selected as main constituents of peptides and proteins during chemical evolution, D-aspartyl (Asp) residue is found in a variety of living tissues. In particular, D-β-Asp is thought to be stable than any other Asp isomers, and this could be a reason for gradual accumulation in abnormal proteins and peptides to modify their structures and functions. It is predicted that D-β-Asp shows high resistance to biomolecular reactions. For instance, less reactivity of D-β-Asp is expected to bond cleavage, although such information has not been provided yet. In this work, the spontaneous peptide bond cleavage was compared between Asp isomers, by applying real-time solution-state NMR to eye lens αΑ-crystallin 51–60 fragment, S51LFRTVLD58SG60 and αΒ-crystallin 61–67 analog, F61D62TGLSG67 consisting of L-α- and D-β-Asp 58 and 62, respectively. Kinetic analysis showed how tough the uncommon D-β-Asp residue was against the peptide bond cleavage as compared to natural L-α-Asp. Differences in pKa and conformation between L-α- and D-β-Asp side chains were plausible factors to determine reactivity of Asp isomers. The present study, for the first time, provides a rationale to explain less reactivity of D-β-Asp to allow abnormal accumulation. PMID:26876027

  17. Recycling of automobile shredder residue with a microwave pyrolysis combined with high temperature steam gasification.

    PubMed

    Donaj, Pawel; Yang, Weihong; Błasiak, Włodzimierz; Forsgren, Christer

    2010-10-15

    Presently, there is a growing need for handling automobile shredder residues--ASR or "car fluff". One of the most promising methods of treatment ASR is pyrolysis. Apart of obvious benefits of pyrolysis: energy and metals recovery, there is serious concern about the residues generated from that process needing to be recycled. Unfortunately, not much work has been reported providing a solution for treatment the wastes after pyrolysis. This work proposes a new system based on a two-staged process. The ASR was primarily treated by microwave pyrolysis and later the liquid and solid products become the feedstock for the high temperature gasification process. The system development is supported within experimental results conducted in a lab-scale, batch-type reactor at the Royal Institute of Technology (KTH). The heating rate, mass loss, gas composition, LHV and gas yield of producer gas vs. residence time are reported for the steam temperature of 1173 K. The sample input was 10 g and the steam flow rate was 0.65 kg/h. The conversion reached 99% for liquids and 45-55% for solids, dependently from the fraction. The H(2):CO mol/mol ratio varied from 1.72 solids and 1.4 for liquid, respectively. The average LHV of generated gas was 15.8 MJ/Nm(3) for liquids and 15 MJ/Nm(3) for solids fuels. PMID:20580160

  18. D-β-aspartyl residue exhibiting uncommon high resistance to spontaneous peptide bond cleavage

    NASA Astrophysics Data System (ADS)

    Aki, Kenzo; Okamura, Emiko

    2016-02-01

    Although L-amino acids were selected as main constituents of peptides and proteins during chemical evolution, D-aspartyl (Asp) residue is found in a variety of living tissues. In particular, D-β-Asp is thought to be stable than any other Asp isomers, and this could be a reason for gradual accumulation in abnormal proteins and peptides to modify their structures and functions. It is predicted that D-β-Asp shows high resistance to biomolecular reactions. For instance, less reactivity of D-β-Asp is expected to bond cleavage, although such information has not been provided yet. In this work, the spontaneous peptide bond cleavage was compared between Asp isomers, by applying real-time solution-state NMR to eye lens αΑ-crystallin 51-60 fragment, S51LFRTVLD58SG60 and αΒ-crystallin 61-67 analog, F61D62TGLSG67 consisting of L-α- and D-β-Asp 58 and 62, respectively. Kinetic analysis showed how tough the uncommon D-β-Asp residue was against the peptide bond cleavage as compared to natural L-α-Asp. Differences in pKa and conformation between L-α- and D-β-Asp side chains were plausible factors to determine reactivity of Asp isomers. The present study, for the first time, provides a rationale to explain less reactivity of D-β-Asp to allow abnormal accumulation.

  19. Shifts in leaf N:P stoichiometry during rehabilitation in highly alkaline bauxite processing residue sand

    PubMed Central

    Goloran, Johnvie B.; Chen, Chengrong; Phillips, Ian R.; Elser, James J.

    2015-01-01

    Large quantities of sodic and alkaline bauxite residue are produced globally as a by-product from alumina refineries. Ecological stoichiometry of key elements [nitrogen (N) and phosphorus (P)] plays a critical role in establishing vegetation cover in bauxite residue sand (BRS). Here we examined how changes in soil chemical properties over time in rehabilitated sodic and alkaline BRS affected leaf N to P stoichiometry of native species used for rehabilitation. Both Ca and soil pH influenced the shifts in leaf N:P ratios of the study species as supported by consistently significant positive relationships (P < 0.001) between these soil indices and leaf N:P ratios. Shifts from N to P limitation were evident for N-fixing species, while N limitation was consistently experienced by non-N-fixing plant species. In older rehabilitated BRS embankments, soil and plant indices (Ca, Na, pH, EC, ESP and leaf N:P ratios) tended to align with those of the natural ecosystem, suggesting improved rehabilitation performance. These findings highlight that leaf N:P stoichiometry can effectively provide a meaningful assessment on understanding nutrient limitation and productivity of native species used for vegetating highly sodic and alkaline BRS, and is a crucial indicator for assessing ecological rehabilitation performance. PMID:26443331

  20. Long-range seismic recording of the MISTY PICTURE high-explosive test, White Sands Missile Range, New Mexico. Environmental research papers, February 1987-February 1988

    SciTech Connect

    Cipar, J.

    1988-02-04

    The Solid Earth Geophysics Branch of the Air Force Geophysics Laboratory recorded the MISTY PICTURE high-explosive test at nine sites in the Tularosa Basin of southern New Mexico. Each site consisted of a three-component seismometer set and a digital-event recorder. The stations were due south of the explosion between 95 and 127 km. Analysis of P-wave travel times indicates that the crust is 30-32 km thick beneath the Tularosa Basin, a side graben of the Rio Grande Rift. S-wave travel times are consistent with earlier surface-wave results. Polarization analysis indicates complex scattered and converted energy between the P- and S-wave groups.