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Sample records for unmarked plastic explosives

  1. 27 CFR 555.180 - Prohibitions relating to unmarked plastic explosives.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... unmarked plastic explosives. 555.180 Section 555.180 Alcohol, Tobacco Products, and Firearms BUREAU OF... Marking of Plastic Explosives § 555.180 Prohibitions relating to unmarked plastic explosives. (a) No person shall manufacture any plastic explosive that does not contain a detection agent. (b) No...

  2. 27 CFR 555.180 - Prohibitions relating to unmarked plastic explosives.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... unmarked plastic explosives. 555.180 Section 555.180 Alcohol, Tobacco Products, and Firearms BUREAU OF... Marking of Plastic Explosives § 555.180 Prohibitions relating to unmarked plastic explosives. (a) No person shall manufacture any plastic explosive that does not contain a detection agent. (b) No...

  3. 27 CFR 555.180 - Prohibitions relating to unmarked plastic explosives.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... unmarked plastic explosives. 555.180 Section 555.180 Alcohol, Tobacco Products, and Firearms BUREAU OF... Marking of Plastic Explosives § 555.180 Prohibitions relating to unmarked plastic explosives. (a) No person shall manufacture any plastic explosive that does not contain a detection agent. (b) No...

  4. 27 CFR 555.180 - Prohibitions relating to unmarked plastic explosives.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... unmarked plastic explosives. 555.180 Section 555.180 Alcohol, Tobacco Products, and Firearms BUREAU OF... Marking of Plastic Explosives § 555.180 Prohibitions relating to unmarked plastic explosives. (a) No person shall manufacture any plastic explosive that does not contain a detection agent. (b) No...

  5. 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.

  6. 27 CFR 555.181 - Reporting of plastic explosives.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Reporting of plastic..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of Plastic Explosives § 555.181 Reporting of plastic explosives. All persons, other than an agency of the United...

  7. 27 CFR 555.181 - Reporting of plastic explosives.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Reporting of plastic..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of Plastic Explosives § 555.181 Reporting of plastic explosives. All persons, other than an agency of the United...

  8. 27 CFR 555.181 - Reporting of plastic explosives.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Reporting of plastic..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of Plastic Explosives § 555.181 Reporting of plastic explosives. All persons, other than an agency of the United...

  9. 27 CFR 555.181 - Reporting of plastic explosives.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Reporting of plastic..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of Plastic Explosives § 555.181 Reporting of plastic explosives. All persons, other than an agency of the United...

  10. 27 CFR 555.181 - Reporting of plastic explosives.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Reporting of plastic..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of Plastic Explosives § 555.181 Reporting of plastic explosives. All persons, other than an agency of the United...

  11. 27 CFR 555.180 - Prohibitions relating to unmarked plastic explosives.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... imported or brought into, or manufactured in the United States prior to April 24, 1996, by or on behalf of... the United States, i.e., not later than June 21, 2013. (c) No person shall ship, transport, transfer... that was imported or brought into, or manufactured in the United States prior to April 24, 1996, by...

  12. Microscopical examination of plastic-bonded explosives

    SciTech Connect

    Skidmore, C.B.; Phillips, D.S.; Crane, N.B.

    1997-10-01

    Polarized Light Microscopy is a powerful technique for the identification of powdered explosives. The authors apply the technique here to the characterization in bulk of composite, plastic-bonded explosives, typically consisting of 95 w/o explosive particulate and 5 w/o polymeric binder. Mounting and polishing techniques are described, along with attendant issues of mount dyeing and some complications of cleaning very soft samples. The microstructures of PBX 9501 (based on cyclotetramethylene tetranitramine, or HMX), PBX 9502 (based on triaminotrinitrobenzene or TATB), and X-0535 (based on diaminotetrazine dioxide, or TZX) are compared and contrasted. Selected case studies are presented in which development of prominent structural characteristics, such as particle size and crack density, are tracked from the starting powders through formulation and pressing to serviceable, formed articles.

  13. Microstructural Characterization of Plastic Bonded Explosives

    NASA Astrophysics Data System (ADS)

    Yeager, John; Hooks, Daniel; Bahr, David

    2010-03-01

    Plastic bonded explosives (PBX), a mixture of hard, anisotropic grains in a compliant matrix, represent an interesting case for understanding composite mechanical response and failure. PBX 9501 (0.95 cyclotetramethylene tetranitramine [HMX], 0.05 polymer binder) is relatively safe formulation of HMX, which is thought to be due to the high compliance of the binder. Crack formation between the crystals and the binder has been observed in this and many other systems and is usually the failure mechanism of PBX materials under mechanical strain. Thus the properties of the crystal-binder interface are important for development of failure models. The interfacial properties of PBX 9501 as well as an inert simulant have been characterized using several methods. Surface energies of several polymer binders and various crystallographic faces of HMX have been determined with a contact angle measurement technique, allowing for thermodynamic work of adhesion at the interface to be calculated. Surface roughness of the crystal faces has been measured with atomic force microscopy (AFM). PBX formulation methods are suspected to lead to a diffuse interface, but the nature of this interface has not previously been characterized in detail. Here, the coherence of the interface has been studied using tapping mode AFM for modulus contrast, and these findings are correlated with results from diffraction techniques.

  14. Compacting Plastic-Bonded Explosive Molding Powders to Dense Solids

    SciTech Connect

    B. Olinger

    2005-04-15

    Dense solid high explosives are made by compacting plastic-bonded explosive molding powders with high pressures and temperatures for extended periods of time. The density is influenced by manufacturing processes of the powders, compaction temperature, the magnitude of compaction pressure, pressure duration, and number of repeated applications of pressure. The internal density variation of compacted explosives depends on method of compaction and the material being compacted.

  15. A parametric pressing study using a plastic-bonded explosive

    SciTech Connect

    Hayden, D. J.; Maez, L. R.; Olinger, B. W.; Powell, S. J.

    2002-01-01

    Pressed plastic-bonded explosives, PBXs, are commonly used by defense and private industry. PBX 9501 is composed of HMX crystals held together with a plastic binder 'softened' with plasticizers. The detonation behavior of any explosive is very dependent upon its density, with the desire to have a uniform, high density throughout the explosive component. A parametric study has been performed pressing PBX 9501 hydrostatically and uniaxially. The effects of several pressing parameters on the bulk density and density profile, as well as mechanical properties, have been measured. The parameters investigated include pressure, temperature, number of cycles, dwell time, rest time, sack thickness, and particle distribution and size. Density distributions within the pressed explosives were also compared.

  16. Mesoscale numerical modeling of plastic bonded explosives under shock loading

    NASA Astrophysics Data System (ADS)

    Shang, Hailin; Zhao, Feng; Ji, Guangfu; Fu, Hua

    2015-09-01

    Mesoscale responses of plastic bonded explosives under shock loading are investigated using material point method as implemented in the Uintah Computational Framework. The two-dimensional geometrical model which can approximately reflect the mesoscopic structure of plastic bonded explosives was created based on the Voronoi tessellation. Shock loading for the explosive was performed by a piston moving at a constant velocity. For the purpose of investigating the influence of shock strength on the responses of explosives, two different velocities for the piston were used, 200 m/s and 400 m/s, respectively. The simulation results indicate that under shock loading there forms some stress localizations on the grain boundary of explosive. These stress localizations lead to large plastic deformations, and the plastic strain energy transforms to thermal energy immediately, causing temperature to rise rapidly and form some hot spots on grain boundary areas. The comparison between two different piston velocities shows that with increasing shock strength, the distribution of plastic strain and temperature does not have significant change, but their values increase obviously. Namely, the higher the shock strength is, the higher the hot spot temperature will be.

  17. Aktau Plastics Plant Explosives Material Report

    SciTech Connect

    CASE JR.,ROGER S.

    1999-12-01

    The U.S. Department of Energy (DOE) has been cooperating with the Republic of Kazakhstanin Combined Threat Reduction (CTR) activities at the BN350 reactor located at the Mangyshlak Atomic Energy Complex (MAEC) in the city of Aktau, Kazakhstan since 1994. DOE contract personnel have been stationed at this facility for the last two years and DOE representatives regularly visit this location to oversee the continuing cooperative activities. Continued future cooperation is planned. A Russian news report in September 1999 indicated that 75 metric tons of organic peroxides stored at the Plastics Plant near Aktau were in danger of exploding and killing or injuring nearby residents. To ensure the health and safety of the personnel at the BN350 site, the DOE conducted a study to investigate the potential danger to the BN350 site posed by these materials at the Plastics Plant. The study conclusion was that while the organic peroxides do have hazards associated with them, the BN350 site is a safe distance from the Plastics Plant. Further, because the Plastics Plant and MAEC have cooperative fire-fighting agreements,and the Plastics Plant had exhausted its reserve of fire-fighting foam, there was the possibility of the Plastics Plant depleting the store of fire-fighting foam at the BN350 site. Subsequently, the DOE decided to purchase fire-fighting foam for the Plastics Plant to ensure the availability of free-fighting foam at the BN350 site.

  18. Microstructural characterization of simulated plastic-bonded explosives

    NASA Astrophysics Data System (ADS)

    Yeager, John David

    2011-12-01

    Plastic-bonded explosives (PBX) are highly complex molecular composites. Recent mechanical investigations of PBX properties, in particular deformation and failure under uniaxial and cyclic loading, have revealed microstructure-dependent fracture behavior. A methodology of characterizing the relationship between microstructure and mechanical properties of PBX materials has been developed and tested on simulated materials with particular focus on the interface. Synchrotron X-ray studies of molecular crystals, explosive binders and formulated simulant composites revealed some intriguing possibilities in real-time observation of cracks, bubbles, delamination, and void collapse during high-speed loading events. A surface energy and thermomechanical study of several molecular crystals, including explosives, and potential binder candidates revealed thermodynamic interactions were not likely to be more important than mechanical properties for insensitive explosives. Ellipsometry and neutron reflectometry were used to identify the interfacial structure of polymer-acetaminophen (an explosive simulant) composites. The crystal-polymer interfacial structure was altered by inclusion of a plasticizing agent -- an important result considering the commonality of plasticizing polymers in PBX formulation. The difference in interfacial properties was also observed mechanically with nanoindentation. Specifically, the plasticizer inhibited formation of a large, diffuse interface / interphase and resulted in a composite which was more likely to experience film delamination than the non-plasticized composite. The difference in mechanical behavior caused by the difference in interfacial structure has important implications for crack initiation and explosive sensitivity. Additionally, certain crystalbinder composites were investigated with a new delamination test, which, while preliminary, resulted in additional insights into fracture behavior. The methodology presented herein provides a pathway for studying PBXs, or similar composites, from the nano-scale to the macro-scale, both in terms of structure and processing, and shows important relationships between interfacial properties and mechanical behavior.

  19. Fatigue of LX-14 and LX-19 plastic bonded explosives

    SciTech Connect

    Hoffman, D. M., LLNL

    1998-04-23

    The DOD uses the plastic bonded explosive (PBX) LX-14 in a wide variety of applications including shaped charges and explosively forged projectiles. LX- 19 is a higher energy explosive, which could be easily substituted for LX-14 because it contains the identical Estane 5703p binder and more energetic CL-20 explosive. Delivery systems for large shaped charges, such as TOW-2, include the Apache helicopter. Loads associated with vibrations and expansion from thermal excursions in field operations may, even at low levels over long time periods, cause flaws, already present in the PBX to grow. Flaws near the explosive/liner interface of a shaped charge can reduce performance. Small flaws in explosives are one mechanism (the hot spot mechanism) proposed for initiation and growth to detonation of PBXs like LX-14, PBXN 5, LX-04 and LX-17 among others. Unlike cast-cured explosives and propellants, PBXs cannot usually be compression molded to full density. Generally, the amount of explosive ignited by a shock wave is approximately equal to the original void volume. Whether or not these flaws or cracks grow during field operations to an extent sufficient to adversely affect the shaped charge performance or increase the vulnerability of the PBX is the ultimate question this effort could address. Currently the fatigue life of LX-14 under controlled conditions is being studied in order to generate its failure stress as a function of the number of fatigue cycles (S- N curve). Proposed future work will address flaw and crack growth and their relationship to hot-spot concentration and explosive vulnerability to shock and/or fragment initiation.

  20. A Plastic Explosive-Degrading Enzyme

    NASA Astrophysics Data System (ADS)

    Miller, Anne-Frances

    2006-03-01

    The enzyme nitroreductase catalyzes reduction of high explosives such as TNT and RDX. Although a well-resolved ^1H^15N-HSQC is obtained at 37 ^oC, the HSQC at 4 ^oC is concentrated between 7.5 and 8.5 ppm and is comprised of sharp overlapped peaks. Thus, it appears that the protein denatures upon cooling. However, the non-covalently-bound FMN cofactor is not released at the lower temperature. Similarly, ultra-violet CD spectroscopy shows that the protein retains essentially full secondary structural content at 4 ^oC. Thus, it appears that nitroreductase exists as an ensemble of rapidly interconverting loose structures at lower temperature, only adopting a single long-lived structure above 20 ^oC. Both saturation transfer from water and solvent proton exchange measurements, demonstrate that resonances of the poorly-dispersed spectrum represent protons closer to water, and in faster exchange with it. Thus we propose that the single well-defined structure is favored entropically, by release of water molecules that solvate the protein at 4 ^oC. We propose that the loosely structured state plays a role in accommodating binding of diverse substrates.

  1. Taylor impact tests and simulations of plastic bonded explosives

    NASA Astrophysics Data System (ADS)

    Clements, Brad E.; Thompson, Darla; Luscher, D. J.; DeLuca, Racci; Brown, Geoffrey

    2012-03-01

    Taylor impact tests were conducted on plastic bonded explosives PBX 9501 and PBXN-9 for impact velocities between 80 and 214 m/s. High-speed photography was used to image the impact event at a rate of one frame for every 25 μs. For early times, PBXN-9 showed large-deformation mushrooming of the explosive cylinders, followed by fragmentation by an amount proportional to the impact speed, was observed at all velocities. PBX 9501 appeared to be more brittle than PBXN-9, the latter demonstrated a more viscoelastic response. The post-shot fragments were collected and particle size distributions were obtained. The constitutive model ViscoSCRAM was then used to model the Taylor experiments using the finite element code ABAQUS. Prior to the Taylor simulations, ViscoSCRAM was parameterized for the two explosives using uniaxial stress-strain data. Simulating Taylor impact tests validates the model in situations undergoing extreme damage and fragmentation.

  2. Decomposition of Nitroplasticizer in Plastic Bonded Explosive PBX 9501

    NASA Astrophysics Data System (ADS)

    Pauler, Denise

    2005-07-01

    In the plastic bonded explosive PBX 9501, a 50/50 mixture of Estane 5703, a polyester urethane random copolymer, and nitroplastizer (NP) binds the HMX explosive crystals. Chemical kinetic mechanisms are being developed for the thermal degradation of NP for high temperatures (explosions) and low temperatures (natural and accelerated aging studies). The goal of this work is to investigate reaction mechanisms using density functional electronic structure theory in addition to the data obtained from explosion and aging experiments. NP consists of a 50/50 mixture of bis-2,2-dinitropropyl acetal and formal. Using 2,2-dinitro-1-methoxypropane as a model compound, a library of reactions was investigated to propose a mechanism for the decomposition of NP. The current mechanism begins with the elimination of HONO, which remains trapped within the material. HONO then adds onto the backbone of NP, which can lead to the formation of esters and oximes that may react further to produce carbon monoxide, carbon dioxide, and NOx gases. This work is supported by the Enhanced Surveillance Campaign and the Advanced Simulation and Computing program.

  3. Marked vs. Unmarked Structures in Modern Written Arabic (Part I).

    ERIC Educational Resources Information Center

    Thalji, Abdel-Majid I.

    1986-01-01

    Considers marked and unmarked structures in modern Arabic in terms of defending a basic unmarked structure which carries the least presuppositional background to which other surface orders can be related and a lexical treatment of number in Arabic. (CB)

  4. NQR Characteristics of an RDX Plastic Explosives Simulant.

    PubMed

    Turecek, J; Schwitter, B; Miljak, D; Stancl, M

    2012-12-01

    For reliable detection of explosives, a combination of methods integrated within a single measurement platform may increase detection performance. However, the efficient field testing of such measurement platforms requires the use of inexplosive simulants that are detectable by a wide range of methods. Physical parameters such as simulant density, elemental composition and crystalline structure must closely match those of the target explosive. The highly discriminating bulk detection characteristics of nuclear quadrupole resonance (NQR) especially constrain simulant design. This paper describes the development of an inexplosive RDX simulant suited to a wide range of measurement methods, including NQR. Measurements are presented that confirm an RDX NQR response from the simulant. The potential use of the simulant for field testing a prototype handheld NQR-based RDX detector is analyzed. Only modest changes in prototype operation during field testing would be required to account for the use of simulant rather than real explosive. PMID:23204647

  5. Literature review of the lifetime of DOE materials: Aging of plastic bonded explosives and the explosives and polymers contained therein

    SciTech Connect

    Burgess, C.E.; Woodyard, J.D.; Rainwater, K.A.; Lightfoot, J.M.; Richardson, B.R.

    1998-09-01

    There are concerns about the lifetime of the nation`s stockpile of high explosives (HEs) and their components. The DOE`s Core Surveillance and Enhanced Surveillance programs specifically target degradation of HE, binders, and plastic-bonded explosives (PBXs) for determination of component lifetimes and handling procedures. The principal goal of this project is to identify the decomposition mechanisms of HEs, plasticizers, and plastic polymer binders resulting from exposure to ionizing radiation, heat, and humidity. The primary HEs of concern are 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and 1,3,5,7-tetranitro-1,3,5,7-tetraazocyclooctane (HMX). Hexahydro-1,3,5-triazine (RDX) is closely related to these two compounds and is also included in the literature review. Both Kel-F 800 and Estane are polymers of interest. A stabilizer, Irganox 1010, and an energetic plasticizer that is a blend of acetaldehyde 2,2-dinitropropyl acetal, are also of interest, but the focus of this report will be on the explosives and polymers. This presents a literature review that provides background on the synthesis, degradation, and techniques to analyze TATB, HMX, RDX, Kel-F 800, Estane, and the PBXs of these compounds. As there are many factors that can influence degradation of materials, the degradation discussion will be divided into sections based on each factor and how it might affect the degradation mechanism. The factors reviewed that influence the degradation of these materials are exposure to heat, UV- and {gamma}-irradiation, and the chemistry of these compounds. The report presents a recently compiled accounting of the available literature. 80 refs., 7 figs.

  6. Modeling shock responses of plastic bonded explosives using material point method

    NASA Astrophysics Data System (ADS)

    Shang, Hailin; Zhao, Feng; Fu, Hua

    2015-06-01

    Shock responses of plastic bonded explosives are modeled using material point method as implemented in the Uintah Computational Framework. The two-dimensional geometrical model was established based on the micrograph of PBX9501. Shock loading for this explosive was performed by a piston moving at a constant velocity. Simulation results indicate that under shock loading there forms some stress localizations on the grain boundary of HMX explosive. These stress localizations lead to some serious plastic deformation. Simultaneously, the plastic strain energy transforms to thermal energy, causing the temperature to rise rapidly and form some hot spots on grain boundary areas. There are also some micro cracks appear at early time of the shock loading. But after some time these cracks begin to close, forming a few hot spots. The influence of shock strength on the responses of explosive was also investigated by increasing the piston velocity. And the results show that with increasing shock strength, the distribution of plastic strain and temperature does not have significant change, but their values increase obviously. Namely, the higher the shock strength is, the higher the hot spot temperature will be. Supported by the National Natural Science Foundation of China (11272296).

  7. Towards Accurate Molecular Modeling of Plastic Bonded Explosives

    NASA Astrophysics Data System (ADS)

    Chantawansri, T. L.; Andzelm, J.; Taylor, D.; Byrd, E.; Rice, B.

    2010-03-01

    There is substantial interest in identifying the controlling factors that influence the susceptibility of polymer bonded explosives (PBXs) to accidental initiation. Numerous Molecular Dynamics (MD) simulations of PBXs using the COMPASS force field have been reported in recent years, where the validity of the force field in modeling the solid EM fill has been judged solely on its ability to reproduce lattice parameters, which is an insufficient metric. Performance of the COMPASS force field in modeling EMs and the polymeric binder has been assessed by calculating structural, thermal, and mechanical properties, where only fair agreement with experimental data is obtained. We performed MD simulations using the COMPASS force field for the polymer binder hydroxyl-terminated polybutadiene and five EMs: cyclotrimethylenetrinitramine, 1,3,5,7-tetranitro-1,3,5,7-tetra-azacyclo-octane, 2,4,6,8,10,12-hexantirohexaazazisowurzitane, 2,4,6-trinitro-1,3,5-benzenetriamine, and pentaerythritol tetranitate. Predicted EM crystallographic and molecular structural parameters, as well as calculated properties for the binder will be compared with experimental results for different simulation conditions. We also present novel simulation protocols, which improve agreement between experimental and computation results thus leading to the accurate modeling of PBXs.

  8. Pilot-scale base hydrolysis processing of HMX-based plastic-bonded explosives

    SciTech Connect

    Flesner, R.L.; Dell`orco, P.C.; Spontarelli, T.; Bishop, R.L.; Skidmore, C.; Uher, K.J.; Kramer, J.F.

    1996-07-01

    Los Alamos National Laboratory has demonstrated that many energetic materials can be rendered non-energetic via reaction with sodium hydroxide or ammonia. This process is known as base hydrolysis. A pilot scale reactor has been developed to process up to 20 kg of plastic bonded explosive in a single batch operation. In this report, we discuss the design and operation of the pilot scale reactor for the processing of PBX 9404, a standard Department of Energy plastic bonded explosive containing HMX and nitrocellulose. Products from base hydrolysis, although non-energetic, still require additional processing before release to the environment Decomposition products, destruction efficiencies, and rates of reaction for base hydrolysis will be presented. Hydrothermal processing, previously known as supercritical water oxidation, has been proposed for converting organic products from hydrolysis to carbon dioxide, nitrogen, and nitrous oxide. Base hydrolysis in combination with hydrothermal processing may yield a viable alternative to open burning/open detonation for destruction of many energetic materials.

  9. Creep Testing Plastic-Bonded Explosives in Uni-axial Compression

    SciTech Connect

    Gagliardi, F J; Cunningham, B J

    2008-03-13

    High fidelity measurements of time-dependent strain in the plastic-bonded explosives LX-17-1 and PBX 9502 have been performed under constant, uni-axial, compressive load using a custom designed apparatus. The apparatus uses a combination of extensometers and linear variable differential transformers coupled with a data acquisition system, thermal controls, and gravitational loading. The materials being tested consist of a crystalline explosive material mixed with a polymeric binder. The behavior of each material is related to the type of explosive and to the percentage and type of binder. For any given plastic-bonded explosive, the creep behavior is also dependent on the stress level and test temperature. Experiments were conducted using a 3 x 3 stress-temperature matrix with a temperature range of 24 C to 70 C and with stresses ranging from 250-psi to 780-psi. Analysis of the data has shown that logarithmic curve fits provide an accurate means of quantification and facilitate a long-term predictive capability. This paper will discuss the design of the apparatus, experimental results, and analyses.

  10. Clean, agile alternative binders, additives and plasticizers for propellant and explosive formulations

    SciTech Connect

    Hoffman, D.M.; Hawkins, T.W.; Lindsay, G.A.

    1994-12-01

    As part of the Strategic Environmental Research and Development Program (SERDP) a clean, agile manufacturing of explosives, propellants and pyrotechniques (CANPEP) effort set about to identify new approaches to materials and processes for producing propellants, explosives and pyrotechniques (PEP). The RDX based explosive PBXN-109 and gun propellant M-43 were identified as candidates for which waste minimization and recycling modifications might be implemented in a short time frame. The binders, additives and plasticizers subgroup identified cast non-curable thermoplastic elastomer (TPE) formulations as possible replacement candidates for these formulations. Paste extrudable explosives were also suggested as viable alternatives to PBXN-109. Commercial inert and energetic TPEs are reviewed. Biodegradable and hydrolyzable binders are discussed. The applicability of various types of explosive formulations are reviewed and some issues associated with implementation of recyclable formulations are identified. It is clear that some processing and weaponization modifications will need to be made if any of these approaches are to be implemented. The major advantages of formulations suggested here over PBXN-109 and M-43 is their reuse/recyclability. Formulations using TPE or Paste could by recovered from a generic bomb or propellant and reused if they met specification or easily reprocessed and sold to the mining industry.

  11. Noninvasive detection of concealed explosives: depth profiling through opaque plastics by time-resolved Raman spectroscopy.

    PubMed

    Petterson, Ingeborg E Iping; López-López, María; García-Ruiz, Carmen; Gooijer, Cees; Buijs, Joost B; Ariese, Freek

    2011-11-15

    The detection of explosives concealed behind opaque, diffusely scattering materials is a challenge that requires noninvasive analytical techniques for identification without having to manipulate the package. In this context, this study focuses on the application of time-resolved Raman spectroscopy (TRRS) with a picosecond pulsed laser and an intensified charge-coupled device (ICCD) detector for the noninvasive identification of explosive materials through several millimeters of opaque polymers or plastic packaging materials. By means of a short (250 ps) gate which can be delayed several hundred picoseconds after the laser pulse, the ICCD detector allows for the temporal discrimination between photons from the surface of a sample and those from deeper layers. TRRS was applied for the detection of the two main isomers of dinitrotoluene, 2,4-dinitrotoluene, and 2,6-dinitrotoluene as well as for various other components of explosive mixtures, including akardite II, diphenylamine, and ethyl centralite. Spectra were obtained through different diffuse scattering white polymer materials: polytetrafluoroethylene (PTFE), polyoxymethylene (POM), and polyethylene (PE). Common packaging materials of various thicknesses were also selected, including polystyrene (PS) and polyvinyl chloride (PVC). With the demonstration of the ability to detect concealed, explosives-related compounds through an opaque first layer, this study may have important applications in the security and forensic fields. PMID:21967622

  12. Aspects of the Tribology of the Plastic Bonded Explosive LX-04

    SciTech Connect

    Hoffman, D M; Chandler, J B

    2004-07-08

    The coefficient of friction, {mu}, of the plastic bonded explosive (PBX) LX-04 was measured on stainless steel, aluminum, Teflon and the explosive itself as a function of temperature between ambient and 135 C at a rotational speed of 0.0025 rad/sec{sup -1}. An optical profilometer was used to analyze the mean surface roughness, R{sub a}, of the various materials. LX-04 is a composite of the explosive 1,3,5,7-tetranitroazacyclooctane (HMX) and Viton A in an 85/15 weight ratio. The average roughness of the pressed explosive surface was R{sub a} = 0.55 {micro}m. The coefficient of friction for LX-04 on stainless steel of R{sub a} = 0.40 {micro}m decreased from 0.38 at ambient to 0.18 at 95 C. Above this temperature {mu} was nearly constant to about 125 C, where the coefficient began to increase again. The opposite behavior was observed with aluminum with R{sub a} = 0.31 {micro}m. The coefficient of friction increased from about 0.3 at ambient to 0.46 at 125 C. At this temperature or above, {mu} tended to increase during the measurement, indicating that the sample may have been sticking to the counter surface. The coefficient of friction against Teflon of R{sub a} = 0.054 {micro}m was nearly constant from ambient to 65 C at 0.43 {+-} 0.02, then decreased to 0.17 at 100 C and remained there up to 135 C. Against LX-04 itself at temperatures between 35 and 95 C the coefficient of friction averaged 0.64, but tended to increase during the measurement, probably due to adhesion of the Viton to itself. Above 95 C the coefficient dropped off and became nearly constant again at 0.16 from 115 up to 135 C. Some preliminary measurements on stainless steel with the mock explosive RM-04-BR, a composite of cyanuric acid and Viton A in the same weight ratio as the actual explosive, were made to evaluate the set up procedures and safety of the operation with live explosive. Both pressed, R{sub a} = 0.37 {micro}m, and machined, R{sub a} = 1.7 {micro}m, surfaces were evaluated for the mock. Results compared reasonably well with the explosive itself on steel, indicating that the binder plays a major role in determining the coefficient of friction for these types of composites.

  13. On the Nature of Variations in Density and Composition within TATB-based Plastic Bonded Explosives

    SciTech Connect

    Kinney, J H; Willey, T M; Overturf, G

    2006-06-27

    Initiation of insensitive high explosives is affected by porosity in the 100 nm to micron size range. It is also recognized that as-pressed plastic bonded explosives (PBX) are heterogeneous in composition and density at much coarser length scale (10 microns-100 microns). However, variations in density and composition of these explosives have been poorly characterized. Here, we characterize the natural variations in composition and density of TATB-based PBX LX-17 with synchrotron radiation tomography and ultra small angle x-ray scattering. Large scale variations in composition occur as a result of binder enrichment at the prill particle boundaries. The pore fraction is twice as high in the prill particle as in the boundary. The pore distribution is bimodal, with small pores of 50-100 nm in radius and a broader distribution of pores in the 0.5-1.5 micron size range. The higher pore density within the prill particle is attributed to contact asperities between the crystallites that might inhibit complete consolidation and binder infiltration.

  14. Effect of subcritical damage on sensitivity of a plastic bonded explosive

    NASA Astrophysics Data System (ADS)

    Sunny, George; Krawietz, Thomas; Cox, John; Jordan, Jennifer; Rumchik, Chad

    2014-03-01

    As energetic materials are subjected to increasingly extreme environments, a more thorough understanding of the relationships between mechanical insult and changes in explosive sensitivity is desired. To that end, a Shock Wave Apparatus, originally developed at TDW (Schrobenhausen, Germany), has been employed to induce subcritical shocks of up to 0.7 GPa in a plastic bonded explosive sample while preserving the sample for further study. Changes in density due to the subcritical shocks are measured, and the sensitivity of the damaged explosive is determined through a TDW/AFRL Modified Gap Test configuration that allows the run-to-detonation (RTD) to be determined for a given shock loading. Changes in sensitivity are determined by comparing the RTD for each damaged sample with corresponding RTD for pristine (i.e. undamaged) samples. Confined Split-Hopkinson Pressure Bar experiments are also conducted in order to understand the effects of damage at lower strain-rates and pressures. Finally, the effects on sensitivity due to multiple shocks are also investigated in this study. Support was provided by the Air Force Office of Scientific Research, Grant FY12RW03COR.

  15. Microwave frequency material properties and ignition predictions of neat and plastic bound explosives

    NASA Astrophysics Data System (ADS)

    Daily, M.; Son, S.; Glover, B.; Groven, L.

    2013-06-01

    Microwave energy has been considered for ignition, enhanced burning, and detection/defeat of energetic materials. However, the very limited data set of electromagnetic properties for both neat and plastic bound explosives has severely limited design and implementation of detection, defeat, and initiation devices. In this work, we report complex permittivity measurements for both neat and plastic bonded energetic materials such as HMX, RDX, PBX9501, etc. These measurements provide a new, more extensive set of self-consistent data that can be used to predict the response of such materials to electromagnetic energy. Using this data in conjunction with finite element analysis software, a high localized field experimental microwave applicator was designed and microwave heating predictions were calculated. Predictions show the feasibility of heating low-loss energetic materials in such cavities with high local electric fields without the need for susceptor particles. For the plastic bound materials, the effect of the binder is presented, showing that electromagnetic energy is preferentially absorbed in the more absorptive binder, resulting in significant gradients within individual energetic crystals (e.g., HMX crystals in PBX 9501). These predictions are now being used to aid experimental work with the applicator cavity and have demonstrated the feasibility of volumetrically heating energetic materials in short time scales with low microwave power levels.

  16. X-ray Photoelectron Spectroscopy study of the compatibility of the explosive PETN with candidate plastic bonding materials

    SciTech Connect

    Vannet, M.D.; Wang, P.S.; Moddeman, W.E.; Bowling, W.C.

    1985-01-01

    The compatibility of the explosive PETN with two plastic bonding materials, ethyl cellulose and a halogenated vinyl polymer (FPC 461), was determined by X-ray Photoelectron Spectroscopy (XPS). Both were found to coat the PETN crystals, and no change in chemical composition was found in the PETN or the plastic due to either the process or their mutual presence. 3 refs., 1 fig., 1 tab.

  17. Thermal expansion of PBX 9501 and PBX 9502 plastic-bonded explosives

    SciTech Connect

    Thompson, Darla Graff; Brown, Geoff W; Deluca, Racci; Giambra, Anna; Sandstrom, Mary

    2009-01-01

    Two applications of thermal expansion measurements on plastic-bonded explosive (PBX) composites are described. In the first dilatometer application, thermal expansion properties of HMX-based PBX 9501 are measured over a broad thermal range that includes glass and domain-restructuring transitions in the polymeric binder. Results are consistent with other thermal measurements and analyses performed on the composite, as well as on the binder itself. The second application used the dilatometer to distinguish the reversible and irreversible components of thermal expansion in PBX 9502, a TATB-based explosive. Irreversible expansion of the composite is believed to derive from the highly-anisotropic coefficient of thermal expansion (CTE) values measured on single T A TB crystals, although the mechanism is not well understood. Effects of specimen density, thermal ramp rate, and thermal range variation (warm first or cold first) were explored, and the results are presented and discussed. Dilatometer measurements are ongoing towards gaining insight into the mechanism(s) responsible for PBX 9502 irreversible thermal expansion.

  18. Portable standoff Raman system for fast detection of homemade explosives through glass, plastic, and water

    NASA Astrophysics Data System (ADS)

    Misra, Anupam K.; Sharma, Shiv K.; Acosta, Tayro E.; Porter, John N.; Lucey, Paul G.; Bates, David E.

    2012-06-01

    The University of Hawaii has been developing portable remote Raman systems capable of detecting chemicals in daylight from a safe standoff distance. We present data on standoff detection of chemicals used in the synthesis of homemade explosives (HME) using a portable standoff Raman system utilizing an 8-inch telescope. Data show that good-quality Raman spectra of various hazardous chemicals such as ammonium nitrate, potassium nitrate, potassium perchlorate, sulfur, nitrobenzene, benzene, acetone, various organic and inorganic chemicals etc. could be easily obtained from remote distances, tested up to 120 meters, with a single-pulse laser excitation and with detection time less than 1 μs. The system uses a frequency-doubled Nd:YAG pulsed laser source (532 nm, 100 mJ/pulse, 15 Hz, pulse width 10 ns) capable of firing a single or double pulse. The double-pulse configuration also allows the system to perform standoff LIBS (Laser-Induced Breakdown Spectroscopy) at 50 m range. In the standoff Raman detection, the doublepulse sequence simply doubles the signal to noise ratio. Significant improvement in the quality of Raman spectra is observed when the standoff detection is made with 1s integration time. The system uses a 50-micron slit and has spectral resolution of 8 cm-1. The HME chemicals could be easily detected through clear and brown glass bottles, PP and HDPE plastic bottles, and also through fluorescent plastic water bottles. Standoff Raman detection of HME chemical from a 10 m distance through non-visible concealed bottles in plastic bubble wrap packaging is demonstrated with 1 s integration time. Possible applications of the standoff Raman system for homeland security and environmental monitoring are discussed.

  19. Identification of volatile chemical signatures from plastic explosives by SPME-GC/MS and detection by ion mobility spectrometry.

    PubMed

    Lai, Hanh; Leung, Alfred; Magee, Matthew; Almirall, José R

    2010-04-01

    This study demonstrates the use of solid-phase microextraction (SPME) to extract and pre-concentrate volatile signatures from static air above plastic explosive samples followed by detection using ion mobility spectrometry (IMS) optimized to detect the volatile, non-energetic components rather than the energetic materials. Currently, sample collection for detection by commercial IMS analyzers is conducted through swiping of suspected surfaces for explosive particles and vapor sampling. The first method is not suitable for sampling inside large volume areas, and the latter method is not effective because the low vapor pressure of some explosives such as RDX and PETN make them not readily available in the air for headspace sampling under ambient conditions. For the first time, headspace sampling and detection of Detasheet, Semtex H, and C-4 is reported using SPME-IMS operating under one universal setting with limits of detection ranging from 1.5 to 2.5 ng for the target volatile signatures. The target signature compounds n-butyl acetate and the taggant DMNB are associated with untagged and tagged Detasheet explosives, respectively. Cyclohexanone and DMNB are associated with tagged C-4 explosives. DMNB is associated with tagged Semtex H explosives. Within 10 to 60 s of sampling, the headspace inside a glass vial containing 1 g of explosive, more than 20 ng of the target signatures can be extracted by the SPME fiber followed by IMS detection. PMID:20229010

  20. Efficient construction of unmarked recombinant mycobacteria using an improved system.

    PubMed

    Yang, Feng; Tan, Yaoju; Liu, Jia; Liu, Tianzhou; Wang, Bangxing; Cao, Yuanyuan; Qu, Yue; Lithgow, Trevor; Tan, Shouyong; Zhang, Tianyu

    2014-08-01

    The genetic study of mycobacteria, such as Mycobacterium tuberculosis and Mycobacterium ulcerans, is hampered heavily by their slow growth. We have developed efficient, versatile, and improved genetic tools for constructing unmarked recombinant mycobacteria more rapidly including generating multiple mutants using the same antibiotic marker in both fast- and slow-growing mycobacteria. PMID:24873745

  1. Performance evaluation of booster materials in the plastic bonded explosive PBX 9502 in a hemispherical wave breakout test

    SciTech Connect

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

    2008-01-01

    An explosive booster is normally required to initiate detonation in an insensitive high explosive (lHE). Booster materials must be ignitable by a conventional detonator and deliver sufficient energy and favorable pulse shape to initiate the IHE charge. The explosive booster should be as insensitive as reasonably possible to maintain the overall safety margin of the explosive assembly. A hemispherical wave breakout test termed the on ionskin test is one of the methods of testing the performance of booster materials in an initiation train assembly. There are several variations of this basic test which are known by other names. In this test, the wave breakout time-position history at the surface of a hemispherical IHE acceptor charge is recorded, and the relative uniformity of breakout allows qualitative comparison between booster candidates and quantitative comparison of several metrics. The results of a series of onionskin experiments evaluating the performance of some new booster formulations in the triaminotrinitrobenzene (TA TB) -based plastic bonded explosive PBX 9502 will be presented. The boosters were tested in an onionskin arrangement in which the booster pellet was cylindrical, and the tests were performed at a temperature of-55{sup o}C to emphasize variations in spreading performance. The modification from the traditional hemispherical geometry facilitated efficient explosive fabrication and charge assembly, but the results indicate that this geometry was not ideal for several reasons. Despite the complications arising from geometry, promising performance was observed from booster formulations including 3,3' -diamino-4,4'azoxyfurazan.

  2. Line-imaging velocimetry for observing spatially heterogeneous mechanical and chemical responses in plastic bonded explosives during impact

    NASA Astrophysics Data System (ADS)

    Bolme, C. A.; Ramos, K. J.

    2013-08-01

    A line-imaging velocity interferometer was implemented on a single-stage light gas gun to probe the spatial heterogeneity of mechanical response, chemical reaction, and initiation of detonation in explosives. The instrument is described in detail, and then data are presented on several shock-compressed materials to demonstrate the instrument performance on both homogeneous and heterogeneous samples. The noise floor of this diagnostic was determined to be 0.24 rad with a shot on elastically compressed sapphire. The diagnostic was then applied to two heterogeneous plastic bonded explosives: 3,3'-diaminoazoxyfurazan (DAAF) and PBX 9501, where significant spatial velocity heterogeneity was observed during the build up to detonation. In PBX 9501, the velocity heterogeneity was consistent with the explosive grain size, however in DAAF, we observed heterogeneity on a much larger length scale than the grain size that was similar to the imaging resolution of the instrument.

  3. Line-imaging velocimetry for observing spatially heterogeneous mechanical and chemical responses in plastic bonded explosives during impact.

    PubMed

    Bolme, C A; Ramos, K J

    2013-08-01

    A line-imaging velocity interferometer was implemented on a single-stage light gas gun to probe the spatial heterogeneity of mechanical response, chemical reaction, and initiation of detonation in explosives. The instrument is described in detail, and then data are presented on several shock-compressed materials to demonstrate the instrument performance on both homogeneous and heterogeneous samples. The noise floor of this diagnostic was determined to be 0.24 rad with a shot on elastically compressed sapphire. The diagnostic was then applied to two heterogeneous plastic bonded explosives: 3,3(')-diaminoazoxyfurazan (DAAF) and PBX 9501, where significant spatial velocity heterogeneity was observed during the build up to detonation. In PBX 9501, the velocity heterogeneity was consistent with the explosive grain size, however in DAAF, we observed heterogeneity on a much larger length scale than the grain size that was similar to the imaging resolution of the instrument. PMID:24007075

  4. An initial evaluation of stable isotopic characterisation of post-blast plastic debris from improvised explosive devices.

    PubMed

    Quirk, Anthony T; Bellerby, John M; Carter, James F; Thomas, Fay A; Hill, Jenny C

    2009-06-01

    A number of two-way radios, similar to those which have been employed to initiate Improvised Explosive Devices (IEDs), were acquired from a commercial supplier and grouped into four pairs. Samples of plastic material were collected from five distinct regions of each radio and analysed by Infrared and Raman spectroscopy to identify the nature of the material. One radio of each pair was then subjected to detonation with a commercially available plastic explosive. The combination of radio and explosive was considered to be representative of the components of an IED. Following detonation, fragments were recovered and, where possible, identified as specific sampling points of the radio. A combination of delta2H and delta13C stable isotopic analysis of material from each of the five sampling points was found to provide a pattern which was characteristic of a given radio and provided a means to associate pairs of radios. When few fragments were recovered, no positive association could be made between the fragments and the paired, undamaged radio. This was attributed, in part, to manufacturing variation in the radios. However, when three or more post-blast fragments were recovered it was possible to associate these with the paired, undamaged radio with a high degree of certainty. PMID:19606586

  5. 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.

  6. Detonation wave profiles measured in plastic bonded explosives using 1550 nm photon doppler velocimetry (PDV)

    SciTech Connect

    Gustavsen, Richard L; Bartram, Brian D; Sanchez, Nathaniel J

    2009-01-01

    We present detonation wave profiles measured in two TATB based explosives and two HMX based explosives. Profiles were measured at the interface of the explosive and a Lithium-Fluoride (LiF) window using 1550 nm Photon Doppler Velocimetry (PDV). Planar detonations were produced by impacting the explosive with a projectile launched in a gas-gun. The impact state was varied to produce varied distance to detonation, and therefore varied support of the Taylor wave following the Chapman-Jouget (CJ) or sonic state. Profiles from experiments with different support should be the same between the Von-Neumann (VN) spike and CJ state and different thereafter. Comparison of profiles with differing support, therefore, allows us to estimate reaction zone lengths. For the TATB based explosive, a reaction zone length of {approx} 3.9 mm, 500 ns was measured in EDC-35, and a reaction zone length of {approx} 6.3 mm, 800 ns was measured in PBX 9502 pre-cooled to -55 C. The respective VN spike state was 2.25 {+-} 0.05 km/s in EDC-35 and 2.4 {+-} 0.1 km/s in the cooled PBX 9502. We do not believe we have resolved either the VN spike state (> 2.6 km/s) nor the reaction zone length (<< 50 ns) in the HMX based explosives.

  7. Inference about density and temporary emigration in unmarked populations

    USGS Publications Warehouse

    Chandler, Richard B.; Royle, J. Andrew; King, David I.

    2011-01-01

    Few species are distributed uniformly in space, and populations of mobile organisms are rarely closed with respect to movement, yet many models of density rely upon these assumptions. We present a hierarchical model allowing inference about the density of unmarked populations subject to temporary emigration and imperfect detection. The model can be fit to data collected using a variety of standard survey methods such as repeated point counts in which removal sampling, double-observer sampling, or distance sampling is used during each count. Simulation studies demonstrated that parameter estimators are unbiased when temporary emigration is either "completely random" or is determined by the size and location of home ranges relative to survey points. We also applied the model to repeated removal sampling data collected on Chestnut-sided Warblers (Dendroica pensylvancia) in the White Mountain National Forest, USA. The density estimate from our model, 1.09 birds/ha, was similar to an estimate of 1.11 birds/ha produced by an intensive spot-mapping effort. Our model is also applicable when processes other than temporary emigration affect the probability of being available for detection, such as in studies using cue counts. Functions to implement the model have been added to the R package unmarked.

  8. 9 CFR 325.5 - Unmarked inspected product transported under official seal between official establishments for...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Unmarked inspected product transported... CERTIFICATION TRANSPORTATION § 325.5 Unmarked inspected product transported under official seal between official... transported from one official establishment to another for further processing without each article...

  9. Constitutive response of two plastic-bonded explosive binder materials as a function of temperature and strain-rate

    SciTech Connect

    Cady, C. M.; Blumenthal, W. R.; Gray, G. T. , III; Idar, D. J.

    2004-01-01

    Recently, interest has been shown concerning the mechanical response of plastic-bonded explosives (PBX) and propellants to enable the development of predictive materials models describing the mechanical behavior of these composites. Accordingly, detailed information about the constitutive response is crucial. Compression measurements were conducted on two explosive formulation binders, extruded Estane{trademark} 5703 (hereafter referred to as Estane) and plasticized Estane as a function of temperature from -60 C to +23 C using a specially-designed split Hopkinson pressure bar (strain rate of {approx} 2800 s{sup -1}) and quasi-stattically (strain rates from {approx} 0.001 to 1 s{sup -1}) using a hydraulic load frame. The mechanical response of the Estane was found to exhibit a stronger dependency on strain rate and temperature and higher flow strength for similar test conditions of the materials tested. Plasticized Estane was less sensitively dependent on strain rate and temperature. The visco-elastic recovery of both binders is seen to dominate the mechanical behavior at temperatures above the glass transition temperature (T{sub g}). The binders exhibited increasing elastic loading moduli, E, with increasing strain rate or decreasing temperature, which is similar to other polymeric materials. There is a pronounced shift in the apparent T{sub g} to higher temperatures as the strain rate is increased. At low strain rates the binders exhibit a yield behavior followed by a drop in the flow stress which may or may not recover. At high strain rates the load drop does not occur and the flow stresses level out. A discussion of the Hopkinson bar technique as applied to polymeric or low impedance materials is described in detail.

  10. Implementation of strength and burn models for plastic-bonded explosives and propellants

    SciTech Connect

    Reaugh, J E

    2009-05-07

    We have implemented the burn model in LS-DYNA. At present, the damage (porosity and specific surface area) is specified as initial conditions. However, history variables that are used by the strength model are reserved as placeholders for the next major revision, which will be a completely interactive model. We have implemented an improved strength model for explosives based on a model for concrete. The model exhibits peak strength and subsequent strain softening in uniaxial compression. The peak strength increases with increasing strain rate and/or reduced ambient temperature. Under triaxial compression compression, the strength continues to increase (or at least not decrease) with increasing strain. This behaviour is common to both concrete and polymer-bonded explosives (PBX) because the microstructure of these composites is similar. Both have aggregate material with a broad particle size distribution, although the length scale for concrete aggregate is two orders of magnitude larger than for PBX. The (cement or polymer) binder adheres to the aggregate, and is both pressure and rate sensitive. There is a larger bind binder content in concrete, compared to the explosive, and the aggregates have different hardness. As a result we expect the parameter values to differ, but the functional forms to be applicable to both. The models have been fit to data from tests on an AWE explosive that is HMX based. The decision to implement the models in LS-DYNA was based on three factors: LS-DYNA is used routinely by the AWE engineering analysis group and has a broad base of experienced users; models implemented in LS-DYNA can be transferred easily to LLNL's ALE 3D using a material model wrapper developed by Rich Becker; and LS-DYNA could accommodate the model requirements for a significant number of additional history variables without the significant time delay associated with code modification.

  11. Mechanisms of high strain, high strain rate plastic flow in the explosively driven collapse of Ni-Al laminate cylinders

    NASA Astrophysics Data System (ADS)

    Olney, Karl; Chiu, Po-Hsun; Higgins, Andrew; Serge, Matthew; Fritz, Gregory; Stover, Adam; Benson, David; Nesterenko, Vitali

    2013-06-01

    Laminate materials composed of thin Ni and Al foils have shown promise as material systems used in reactive material applications due to the ability of the material to support a self-sustaining reaction between the Al and Ni layers. In addition to the traditional ignition methods, ignition may occur in the shear bands developed during mechanical loading. The thick-walled cylinder (TWC) technique was performed on samples of Ni-Al laminate materials with two different mesostructues; concentric and corrugated both constructed using alternating layers of Ni and Al thin foils on the order of 20-30 micron foil thickness. These TWC experiments were performed to examine how these materials accommodated large plastic strain during the collapse which may be used to tailor reactivity in the material system. Large scale numerical simulations of these specimens with mesostuctures digitized from the experimental samples were conducted to provide an insight into the mesoscale mechanisms of plastic flow during collapse of the thick walled laminate material during the explosive loading. Funding was provided by ONR MURI N00014-07-1-0740 (Program Officer Dr. Clifford Bedford)

  12. Modeling structured population dynamics using data from unmarked individuals

    USGS Publications Warehouse

    Grant, Evan H. Campbell; Zipkin, Elise; Thorson, James T.; See, Kevin; Lynch, Heather J.; Kanno, Yoichiro; Chandler, Richard; Letcher, Benjamin H.; Royle, J. Andrew

    2014-01-01

    The study of population dynamics requires unbiased, precise estimates of abundance and vital rates that account for the demographic structure inherent in all wildlife and plant populations. Traditionally, these estimates have only been available through approaches that rely on intensive mark–recapture data. We extended recently developed N-mixture models to demonstrate how demographic parameters and abundance can be estimated for structured populations using only stage-structured count data. Our modeling framework can be used to make reliable inferences on abundance as well as recruitment, immigration, stage-specific survival, and detection rates during sampling. We present a range of simulations to illustrate the data requirements, including the number of years and locations necessary for accurate and precise parameter estimates. We apply our modeling framework to a population of northern dusky salamanders (Desmognathus fuscus) in the mid-Atlantic region (USA) and find that the population is unexpectedly declining. Our approach represents a valuable advance in the estimation of population dynamics using multistate data from unmarked individuals and should additionally be useful in the development of integrated models that combine data from intensive (e.g., mark–recapture) and extensive (e.g., counts) data sources.

  13. 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.

  14. 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.

  15. 10 CFR 1045.45 - Review of unmarked documents with potential restricted data or formerly restricted data.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Review of unmarked documents with potential restricted data or formerly restricted data. 1045.45 Section 1045.45 Energy DEPARTMENT OF ENERGY (GENERAL... Restricted Data and Formerly Restricted Data § 1045.45 Review of unmarked documents with potential...

  16. 10 CFR 1045.45 - Review of unmarked documents with potential restricted data or formerly restricted data.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Review of unmarked documents with potential restricted data or formerly restricted data. 1045.45 Section 1045.45 Energy DEPARTMENT OF ENERGY (GENERAL... Restricted Data and Formerly Restricted Data § 1045.45 Review of unmarked documents with potential...

  17. 9 CFR 325.5 - Unmarked inspected product transported under official seal between official establishments for...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... under official seal between official establishments for further processing; certificate. 325.5 Section... CERTIFICATION TRANSPORTATION § 325.5 Unmarked inspected product transported under official seal between official... other means of conveyance which is sealed by a Program employee with an official seal of the...

  18. 9 CFR 325.5 - Unmarked inspected product transported under official seal between official establishments for...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... under official seal between official establishments for further processing; certificate. 325.5 Section... CERTIFICATION TRANSPORTATION § 325.5 Unmarked inspected product transported under official seal between official... other means of conveyance which is sealed by a Program employee with an official seal of the...

  19. 9 CFR 316.8 - Unmarked inspected products; moved between official establishments; moved in commerce.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... between official establishments; moved in commerce. 316.8 Section 316.8 Animals and Animal Products FOOD... commerce. (a) Unmarked products which have been inspected and passed but do not bear the official... from such closed container the product may not be further transported in commerce unless such...

  20. 9 CFR 316.8 - Unmarked inspected products; moved between official establishments; moved in commerce.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... between official establishments; moved in commerce. 316.8 Section 316.8 Animals and Animal Products FOOD... commerce. (a) Unmarked products which have been inspected and passed but do not bear the official... from such closed container the product may not be further transported in commerce unless such...

  1. 9 CFR 316.8 - Unmarked inspected products; moved between official establishments; moved in commerce.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... between official establishments; moved in commerce. 316.8 Section 316.8 Animals and Animal Products FOOD... commerce. (a) Unmarked products which have been inspected and passed but do not bear the official... from such closed container the product may not be further transported in commerce unless such...

  2. 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.

  3. 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.

  4. Unmarked: An R package for fitting hierarchical models of wildlife occurrence and abundance

    USGS Publications Warehouse

    Fiske, I.J.; Chandler, R.B.

    2011-01-01

    Ecological research uses data collection techniques that are prone to substantial and unique types of measurement error to address scientic questions about species abundance and distribution. These data collection schemes include a number of survey methods in which unmarked individuals are counted, or determined to be present, at spatially- referenced sites. Examples include site occupancy sampling, repeated counts, distance sampling, removal sampling, and double observer sampling. To appropriately analyze these data, hierarchical models have been developed to separately model explanatory variables of both a latent abundance or occurrence process and a conditional detection process. Because these models have a straightforward interpretation paralleling mecha- nisms under which the data arose, they have recently gained immense popularity. The common hierarchical structure of these models is well-suited for a unied modeling in- terface. The R package unmarked provides such a unied modeling framework, including tools for data exploration, model tting, model criticism, post-hoc analysis, and model comparison.

  5. unmarked: An R package for fitting hierarchical models of wildlife occurrence and abundance

    USGS Publications Warehouse

    Fiske, Ian J.; Chandler, Richard B.

    2011-01-01

    Ecological research uses data collection techniques that are prone to substantial and unique types of measurement error to address scientific questions about species abundance and distribution. These data collection schemes include a number of survey methods in which unmarked individuals are counted, or determined to be present, at spatially- referenced sites. Examples include site occupancy sampling, repeated counts, distance sampling, removal sampling, and double observer sampling. To appropriately analyze these data, hierarchical models have been developed to separately model explanatory variables of both a latent abundance or occurrence process and a conditional detection process. Because these models have a straightforward interpretation paralleling mechanisms under which the data arose, they have recently gained immense popularity. The common hierarchical structure of these models is well-suited for a unified modeling interface. The R package unmarked provides such a unified modeling framework, including tools for data exploration, model fitting, model criticism, post-hoc analysis, and model comparison.

  6. Efficient and simple generation of multiple unmarked gene deletions in Mycobacterium smegmatis

    PubMed Central

    Mao, Xu-Jian; Yan, Mei-Yi; Zhu, Hui; Guo, Xiao-Peng; Sun, Yi-Cheng

    2016-01-01

    Research on mycobacterial genetics relies heavily on techniques for directed gene mutation, but genetic studies are often hampered by the difficulty of generating gene deletions in mycobacteria. We developed an efficient and improved deletion system, described here in detail, which can be used to construct multiple unmarked recombinants in mycobacteria. We tested this system by using it to sequentially delete four pairs of toxin-antitoxin genes in Mycobacterium smegmatis. PMID:26972108

  7. Laser Feedback Interferometry as a Tool for Analysis of Granular Materials at Terahertz Frequencies: Towards Imaging and Identification of Plastic Explosives

    PubMed Central

    Han, She; Bertling, Karl; Dean, Paul; Keeley, James; Burnett, Andrew D.; Lim, Yah Leng; Khanna, Suraj P.; Valavanis, Alexander; Linfield, Edmund H.; Davies, A. Giles; Indjin, Dragan; Taimre, Thomas; Rakić, Aleksandar D.

    2016-01-01

    We propose a self-consistent method for the analysis of granular materials at terahertz (THz) frequencies using a quantum cascade laser. The method is designed for signals acquired from a laser feedback interferometer, and applied to non-contact reflection-mode sensing. Our technique is demonstrated using three plastic explosives, achieving good agreement with reference measurements obtained by THz time-domain spectroscopy in transmission geometry. The technique described in this study is readily scalable: replacing a single laser with a small laser array, with individual lasers operating at different frequencies will enable unambiguous identification of select materials. This paves the way towards non-contact, reflection-mode analysis and identification of granular materials at THz frequencies using quantum cascade lasers. PMID:27005629

  8. Laser Feedback Interferometry as a Tool for Analysis of Granular Materials at Terahertz Frequencies: Towards Imaging and Identification of Plastic Explosives.

    PubMed

    Han, She; Bertling, Karl; Dean, Paul; Keeley, James; Burnett, Andrew D; Lim, Yah Leng; Khanna, Suraj P; Valavanis, Alexander; Linfield, Edmund H; Davies, A Giles; Indjin, Dragan; Taimre, Thomas; Rakić, Aleksandar D

    2016-01-01

    We propose a self-consistent method for the analysis of granular materials at terahertz (THz) frequencies using a quantum cascade laser. The method is designed for signals acquired from a laser feedback interferometer, and applied to non-contact reflection-mode sensing. Our technique is demonstrated using three plastic explosives, achieving good agreement with reference measurements obtained by THz time-domain spectroscopy in transmission geometry. The technique described in this study is readily scalable: replacing a single laser with a small laser array, with individual lasers operating at different frequencies will enable unambiguous identification of select materials. This paves the way towards non-contact, reflection-mode analysis and identification of granular materials at THz frequencies using quantum cascade lasers. PMID:27005629

  9. Abundance, stock origin, and length of marked and unmarked juvenile Chinook salmon in the surface waters of greater Puget Sound

    USGS Publications Warehouse

    Rice, C.A.; Greene, C.M.; Moran, P.; Teel, D.J.; Kuligowski, D.R.; Reisenbichler, R.R.; Beamer, E.M.; Karr, J.R.; Fresh, K.L.

    2011-01-01

    This study focuses on the use by juvenile Chinook salmon Oncorhynchus tshawytscha of the rarely studied neritic environment (surface waters overlaying the sublittoral zone) in greater Puget Sound. Juvenile Chinook salmon inhabit the sound from their late estuarine residence and early marine transition to their first year at sea. We measured the density, origin, and size of marked (known hatchery) and unmarked (majority naturally spawned) juveniles by means of monthly surface trawls at six river mouth estuaries in Puget Sound and the areas in between. Juvenile Chinook salmon were present in all months sampled (April-November). Unmarked fish in the northern portion of the study area showed broader seasonal distributions of density than did either marked fish in all areas or unmarked fish in the central and southern portions of the sound. Despite these temporal differences, the densities of marked fish appeared to drive most of the total density estimates across space and time. Genetic analysis and coded wire tag data provided us with documented individuals from at least 16 source populations and indicated that movement patterns and apparent residence time were, in part, a function of natal location and time passed since the release of these fish from hatcheries. Unmarked fish tended to be smaller than marked fish and had broader length frequency distributions. The lengths of unmarked fish were negatively related to the density of both marked and unmarked Chinook salmon, but those of marked fish were not. These results indicate more extensive use of estuarine environments by wild than by hatchery juvenile Chinook salmon as well as differential use (e.g., rearing and migration) of various geographic regions of greater Puget Sound by juvenile Chinook salmon in general. In addition, the results for hatchery-generated timing, density, and length differences have implications for the biological interactions between hatchery and wild fish throughout Puget Sound. ?? American Fisheries Society 2011.

  10. idTracker: tracking individuals in a group by automatic identification of unmarked animals.

    PubMed

    Prez-Escudero, Alfonso; Vicente-Page, Julin; Hinz, Robert C; Arganda, Sara; de Polavieja, Gonzalo G

    2014-07-01

    Animals in groups touch each other, move in paths that cross, and interact in complex ways. Current video tracking methods sometimes switch identities of unmarked individuals during these interactions. These errors propagate and result in random assignments after a few minutes unless manually corrected. We present idTracker, a multitracking algorithm that extracts a characteristic fingerprint from each animal in a video recording of a group. It then uses these fingerprints to identify every individual throughout the video. Tracking by identification prevents propagation of errors, and the correct identities can be maintained indefinitely. idTracker distinguishes animals even when humans cannot, such as for size-matched siblings, and reidentifies animals after they temporarily disappear from view or across different videos. It is robust, easy to use and general. We tested it on fish (Danio rerio and Oryzias latipes), flies (Drosophila melanogaster), ants (Messor structor) and mice (Mus musculus). PMID:24880877

  11. Improving airport explosives detection

    SciTech Connect

    Krause, C.

    1990-01-01

    ORNL has developed the technology to detect hidden explosives in luggage using X ray and neutron detection devices. The Federal Aviation Administration has ordered the airlines to buy and install Thermal Neutron Analysis (TNA) units. The combined pulsed-neutron and X-ray interrogation inspection (CPNX) system developed at ORNL uses less radioactive materials as well as being more sensitive to weapons, electronic devices and plastic explosives.

  12. Spatially explicit models for inference about density in unmarked or partially marked populations

    USGS Publications Warehouse

    Chandler, Richard B.; Royle, J. Andrew

    2013-01-01

    Recently developed spatial capture–recapture (SCR) models represent a major advance over traditional capture–recapture (CR) models because they yield explicit estimates of animal density instead of population size within an unknown area. Furthermore, unlike nonspatial CR methods, SCR models account for heterogeneity in capture probability arising from the juxtaposition of animal activity centers and sample locations. Although the utility of SCR methods is gaining recognition, the requirement that all individuals can be uniquely identified excludes their use in many contexts. In this paper, we develop models for situations in which individual recognition is not possible, thereby allowing SCR concepts to be applied in studies of unmarked or partially marked populations. The data required for our model are spatially referenced counts made on one or more sample occasions at a collection of closely spaced sample units such that individuals can be encountered at multiple locations. Our approach includes a spatial point process for the animal activity centers and uses the spatial correlation in counts as information about the number and location of the activity centers. Camera-traps, hair snares, track plates, sound recordings, and even point counts can yield spatially correlated count data, and thus our model is widely applicable. A simulation study demonstrated that while the posterior mean exhibits frequentist bias on the order of 5–10% in small samples, the posterior mode is an accurate point estimator as long as adequate spatial correlation is present. Marking a subset of the population substantially increases posterior precision and is recommended whenever possible. We applied our model to avian point count data collected on an unmarked population of the northern parula (Parula americana) and obtained a density estimate (posterior mode) of 0.38 (95% CI: 0.19–1.64) birds/ha. Our paper challenges sampling and analytical conventions in ecology by demonstrating that neither spatial independence nor individual recognition is needed to estimate population density—rather, spatial dependence can be informative about individual distribution and density.

  13. A novel method to generate unmarked gene deletions in the intracellular pathogen Rhodococcus equi using 5-fluorocytosine conditional lethality

    PubMed Central

    van der Geize, R.; de Jong, W.; Hessels, G. I.; Grommen, A. W. F.; Jacobs, A. A. C.; Dijkhuizen, L.

    2008-01-01

    A novel method to efficiently generate unmarked in-frame gene deletions in Rhodococcus equi was developed, exploiting the cytotoxic effect of 5-fluorocytosine (5-FC) by the action of cytosine deaminase (CD) and uracil phosphoribosyltransferase (UPRT) enzymes. The opportunistic, intracellular pathogen R. equi is resistant to high concentrations of 5-FC. Introduction of Escherichia coli genes encoding CD and UPRT conferred conditional lethality to R. equi cells incubated with 5-FC. To exemplify the use of the codA::upp cassette as counter-selectable marker, an unmarked in-frame gene deletion mutant of R. equi was constructed. The supA and supB genes, part of a putative cholesterol catabolic gene cluster, were efficiently deleted from the R. equi wild-type genome. Phenotypic analysis of the generated ΔsupAB mutant confirmed that supAB are essential for growth of R. equi on cholesterol. Macrophage survival assays revealed that the ΔsupAB mutant is able to survive and proliferate in macrophages comparable to wild type. Thus, cholesterol metabolism does not appear to be essential for macrophage survival of R. equi. The CD-UPRT based 5-FC counter-selection may become a useful asset in the generation of unmarked in-frame gene deletions in other actinobacteria as well, as actinobacteria generally appear to be 5-FC resistant and 5-FU sensitive. PMID:18984616

  14. A method for estimating abundance of mobile populations using telemetry and counts of unmarked animals

    USGS Publications Warehouse

    Clement, Matthew; O'Keefe, Joy M; Walters, Brianne

    2015-01-01

    While numerous methods exist for estimating abundance when detection is imperfect, these methods may not be appropriate due to logistical difficulties or unrealistic assumptions. In particular, if highly mobile taxa are frequently absent from survey locations, methods that estimate a probability of detection conditional on presence will generate biased abundance estimates. Here, we propose a new estimator for estimating abundance of mobile populations using telemetry and counts of unmarked animals. The estimator assumes that the target population conforms to a fission-fusion grouping pattern, in which the population is divided into groups that frequently change in size and composition. If assumptions are met, it is not necessary to locate all groups in the population to estimate abundance. We derive an estimator, perform a simulation study, conduct a power analysis, and apply the method to field data. The simulation study confirmed that our estimator is asymptotically unbiased with low bias, narrow confidence intervals, and good coverage, given a modest survey effort. The power analysis provided initial guidance on survey effort. When applied to small data sets obtained by radio-tracking Indiana bats, abundance estimates were reasonable, although imprecise. The proposed method has the potential to improve abundance estimates for mobile species that have a fission-fusion social structure, such as Indiana bats, because it does not condition detection on presence at survey locations and because it avoids certain restrictive assumptions.

  15. Efficient and simple generation of unmarked gene deletions in Mycobacterium smegmatis.

    PubMed

    Shenkerman, Yael; Elharar, Yifat; Vishkautzan, Marina; Gur, Eyal

    2014-01-01

    Genetic research in molecular laboratories relies heavily on directed mutagenesis and gene deletion techniques. In mycobacteria, however, genetic analysis is often hindered by difficulties in the preparation of deletion mutants. Indeed, in comparison to the allelic exchange systems available for the study of other common model organisms, such as Saccharomyces cerevisiae and Escherichia coli, mycobacterial gene disruption systems suffer from low mutant isolation success rates, mostly due to inefficient homologous recombination and a high degree of non-specific recombination. Here, we present a gene deletion system that combines efficient homologous recombination with advanced screening of mutants. This novel methodology allows for gene disruption in three consecutive steps. The first step relies on the use of phage Che9c recombineering proteins for directed insertion into the chromosome of a linear DNA fragment that encodes GFP and confers hygromycin resistance. In the second step, GFP positive and hygromycin resistant colonies are selected, and in the last step, the gfp-hyg cassette is excised from the chromosome, thus resulting in the formation of an unmarked deletion. We provide a detailed gene deletion methodology and demonstrate the use of this genetic system by deleting the prcSBA operon of Mycobacterium smegmatis. PMID:24100088

  16. 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.

  17. 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.

  18. Geophysical Investigation of an Abandoned Cemetery: Teachers Discover Evidence of Unmarked Graves in Prairie View, TX

    NASA Astrophysics Data System (ADS)

    Henning, A. T.; Sawyer, D. S.; Baldwin, R.; Kahera, A.; Thoms, A.

    2007-12-01

    In July 2007, a group of nineteen K-12 teachers investigated an abandoned cemetery in Prairie View, Texas, utilizing ground-penetrating radar (GPR) to image the subsurface. In a period of two weeks, the group acquired and interpreted 59 GPR profiles in Wyatt Chapel Cemetery and surrounding areas in order to determine the local stratigraphy and try to locate unmarked graves. The sandy soil in this area is ideally suited for GPR investigations and numerous geophysical anomalies were identified. Wyatt Chapel Cemetery is located adjacent to the campus of Prairie View A&M University in Prairie View, TX, and is thought to have originated as a slave burial ground in the 1850's. Participants in a summer course at Rice University conducted a geophysical investigation of the site. Participants were in-service K-12 teachers from urban Houston school districts where the majority of students are members of historically underrepresented minority groups. Recruitment efforts targeted educators who are currently teaching science without a science degree. Participants included elementary, middle and high school teachers. This summer experience is followed by a content-intensive academic year course in Physical Geology. GPR is an excellent tool for investigating the sandy soil encountered at Wyatt Chapel Cemetery. The stratigraphy in the area consists of 3-6 feet of reddish-brown, medium-grained sand overlying a light gray, highly compacted clay. The sand-clay boundary appears as a strong reflector on the GPR profiles. Participants identified numerous anomalies in the GPR data and two were excavated. One consisted of a pair of bright hyperbolae, suggesting two edges of a metal object. This excavation resulted in the discovery of a metal plank thought to be a burial cover. The second anomaly consisted of a break in the horizon representing the top of the clay layer, and subsequent excavation revealed a grave shaft. Participants experienced the process of science first-hand and used geophysics for community service (i.e. restoring an abandoned cemetery). Through background research, they derived a rich historical context for their investigation and learned to appreciate the multi-disciplinary aspect of solving real-world scientific problems.

  19. The effectiveness of ground-penetrating radar surveys in the location of unmarked burial sites in modern cemeteries

    NASA Astrophysics Data System (ADS)

    Fiedler, Sabine; Illich, Bernhard; Berger, Jochen; Graw, Matthias

    2009-07-01

    Ground-penetration radar (GPR) is a geophysical method that is commonly used in archaeological and forensic investigations, including the determination of the exact location of graves. Whilst the method is rapid and does not involve disturbance of the graves, the interpretation of GPR profiles is nevertheless difficult and often leads to incorrect results. Incorrect identifications could hinder criminal investigations and complicate burials in cemeteries that have no information on the location of previously existing graves. In order to increase the number of unmarked graves that are identified, the GPR results need to be verified by comparing them with the soil and vegetation properties of the sites examined. We used a modern cemetery to assess the results obtained with GPR which we then compared with previously obtained tachymetric data and with an excavation of the graves where doubt existed. Certain soil conditions tended to make the application of GPR difficult on occasions, but a rough estimation of the location of the graves was always possible. The two different methods, GPR survey and tachymetry, both proved suitable for correctly determining the exact location of the majority of graves. The present study thus shows that GPR is a reliable method for determining the exact location of unmarked graves in modern cemeteries. However, the method did not allow statements to be made on the stage of decay of the bodies. Such information would assist in deciding what should be done with graves where ineffective degradation creates a problem for reusing graves following the standard resting time of 25 years.

  20. 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.

  1. Bayesian Integration and Classification of Composition C-4 Plastic Explosives Based on Time-of-Flight-Secondary Ion Mass Spectrometry and Laser Ablation-Inductively Coupled Plasma Mass Spectrometry.

    PubMed

    Mahoney, Christine M; Kelly, Ryan T; Alexander, Liz; Newburn, Matt; Bader, Sydney; Ewing, Robert G; Fahey, Albert J; Atkinson, David A; Beagley, Nathaniel

    2016-04-01

    Time-of-flight-secondary ion mass spectrometry (TOF-SIMS) and laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) were used for characterization and identification of unique signatures from a series of 18 Composition C-4 plastic explosives. The samples were obtained from various commercial and military sources around the country. Positive and negative ion TOF-SIMS data were acquired directly from the C-4 residue on Si surfaces, where the positive ion mass spectra obtained were consistent with the major composition of organic additives, and the negative ion mass spectra were more consistent with explosive content in the C-4 samples. Each series of mass spectra was subjected to partial least squares-discriminant analysis (PLS-DA), a multivariate statistical analysis approach which serves to first find the areas of maximum variance within different classes of C-4 and subsequently to classify unknown samples based on correlations between the unknown data set and the original data set (often referred to as a training data set). This method was able to successfully classify test samples of C-4, though with a limited degree of certainty. The classification accuracy of the method was further improved by integrating the positive and negative ion data using a Bayesian approach. The TOF-SIMS data was combined with a second analytical method, LA-ICPMS, which was used to analyze elemental signatures in the C-4. The integrated data were able to classify test samples with a high degree of certainty. Results indicate that this Bayesian integrated approach constitutes a robust classification method that should be employable even in dirty samples collected in the field. PMID:26913559

  2. Explosive Surface Hardening of Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Kovacs-Coskun, T.

    2016-04-01

    In this study, the effects of explosion hardening on the microstructure and the hardness of austenitic stainless steel have been studied. The optimum explosion hardening technology of austenitic stainless steel was researched. In case of the explosive hardening used new idea mean indirect hardening setup. Austenitic stainless steels have high plasticity and can be easily cold formed. However, during cold processing the hardening phenomena always occurs. Upon the explosion impact, the deformation mechanism indicates a plastic deformation and this deformation induces a phase transformation (martensite). The explosion hardening enhances the mechanical properties of the material, includes the wear resistance and hardness. In case of indirect hardening as function of the setup parameters specifically the flayer plate position the hardening increased differently. It was find a relationship between the explosion hardening setup and the hardening level.

  3. Explosive volcanism

    SciTech Connect

    Sheridan, M.F.; Barberi, F.

    1983-01-01

    The 21 papers in this book address the problem of explosive volcanism - a subject that has been the focus of intense research in recent years. Studies of explosive volcanism are important for both basic research into geologic processes and practical application of volcanic phenomena. Models of magma evolution in shallow chamber generally require an interpretation of samples taken from explosive products. Likewise, the evaluation of the potential volcanic risk at active volcanoes and the exploration for geothermal energy in volcanic regions require an understanding of the processes of explosive volcanism and the interaction of subsurface water with magma.

  4. White phosphorus poisoning--explosive encounter.

    PubMed

    Pande, T K; Pandey, S

    2004-03-01

    Poisoning by white or yellow phosphorus is reported in various forms and also in ages varying from infants to adults, but spontaneous combustion and explosion during its management has never been described. This incidence occurred while attempting to pass a Ryle's tube. Its free end first exhibited a yellow flame and this later on led to an explosive encounter. Role of static electricity generated while handling plastic materials leading to ignition and explosion cannot be overlooked. PMID:15636320

  5. An Analytic Tool to Investigate the Effect of Binder on the Sensitivity of HMX-Based Plastic Bonded Explosives in the Skid Test

    SciTech Connect

    D.W. Hayden

    2005-02-01

    This project will develop an analytical tool to calculate performance of HMX based PBXs in the skid test. The skid-test is used as a means to measure sensitivity for large charges in handling situations. Each series of skid tests requires dozens of drops of large billets. It is proposed that the reaction (or lack of one) of PBXs in the skid test is governed by the mechanical properties of the binder. If true, one might be able to develop an analytical tool to estimate skid test behavior for new PBX formulations. Others over the past 50 years have tried to develop similar models. This project will research and summarize the works of others and couple the work of 3 into an analytical tool that can be run on a PC to calculate drop height of HMX based PBXs. Detonation due to dropping a billet is argued to be a dynamic thermal event. To avoid detonation, the heat created due to friction at impact, must be conducted into the charge or the target faster than the chemical kinetics can create additional energy. The methodology will involve numerically solving the Frank-Kamenetskii equation in one dimension. The analytical problem needs to be bounded in terms of how much heat is introduced to the billet and for how long. Assuming an inelastic collision with no rebound, the billet will be in contact with the target for a short duration determined by the equations of motion. For the purposes of the calculations, it will be assumed that if a detonation is to occur, it will transpire within that time. The surface temperature will be raised according to the friction created using the equations of motion of dropping the billet on a rigid surface. The study will connect the works of Charles Anderson, Alan Randolph, Larry Hatler, Alfonse Popolato, and Charles Mader into a single PC based analytic tool. Anderson's equations of motion will be used to calculate the temperature rise upon impact, the time this temperature is maintained (contact time) will be obtained from the work of Hatler et. al., and the reactive temperature rise will be obtained from Mader's work. Finally, the assessment of when a detonation occurs will be derived from Bowden and Yoffe's thermal explosion theory (hot spot).

  6. Explosive welding of pipes

    NASA Astrophysics Data System (ADS)

    Drennov, O.; Burtseva, O.; Kitin, A.

    2006-08-01

    For connection by welding it is suggested to use the explosive welding method. This method is rather new. Nevertheless, it has become commonly used among the technological developments. This method can be advantageous (saving material and physical resources) comparing to its statical analogs (electron-beam welding, argon-arc welding, plasma welding, gas welding, etc.), in particular, in hard-to-reach areas due to their geographic and climatic conditions. The suggestion is to use water as filler. The principle of non-compressibility of liquid under quasi-dynamic loading is used. In one-dimensional gasdynamic and elastic-plastic calculations we determined non-deformed mass of water. Model experiments with pipes having radii R = 57 mm confirmed results of the calculations and the possibility in principle to weld pipes by explosion with use of water as filler.

  7. 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.

  8. 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)

  9. The Generation of Successive Unmarked Mutations and Chromosomal Insertion of Heterologous Genes in Actinobacillus pleuropneumoniae Using Natural Transformation

    PubMed Central

    Bossé, Janine T.; Soares-Bazzolli, Denise M.; Li, Yanwen; Wren, Brendan W.; Tucker, Alexander W.; Maskell, Duncan J.; Rycroft, Andrew N.; Langford, Paul R.

    2014-01-01

    We have developed a simple method of generating scarless, unmarked mutations in Actinobacillus pleuropneumoniae by exploiting the ability of this bacterium to undergo natural transformation, and with no need to introduce plasmids encoding recombinases or resolvases. This method involves two successive rounds of natural transformation using linear DNA: the first introduces a cassette carrying cat (which allows selection by chloramphenicol) and sacB (which allows counter-selection using sucrose) flanked by sequences to either side of the target gene; the second transformation utilises the flanking sequences ligated directly to each other in order to remove the cat-sacB cassette. In order to ensure efficient uptake of the target DNA during transformation, A. pleuropneumoniae uptake sequences are added into the constructs used in both rounds of transformation. This method can be used to generate multiple successive deletions and can also be used to introduce targeted point mutations or insertions of heterologous genes into the A. pleuropneumoniae chromosome for development of live attenuated vaccine strains. So far, we have applied this method to highly transformable isolates of serovars 8 (MIDG2331), which is the most prevalent in the UK, and 15 (HS143). By screening clinical isolates of other serovars, it should be possible to identify other amenable strains. PMID:25409017

  10. Plastic Surgery

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? Plastic Surgery KidsHealth > For Teens > Plastic Surgery Print A A ... her forehead lightened with a laser? What Is Plastic Surgery? Just because the name includes the word "plastic" ...

  11. "Explosive" Physics.

    ERIC Educational Resources Information Center

    Kienzynski, Mark J.

    1998-01-01

    Describes a physics demonstration in which two-liter plastic bottles can be used to show how force relates to pressure and area. Identical drinking straws are launched out of similar plastic bottles with different-sized openings. This demonstration proves qualitatively that pressure is inversely proportional to the area exposed to an object when a…

  12. Explosive signatures: Pre & post blast

    NASA Astrophysics Data System (ADS)

    Bernier, Evan Thomas

    Manuscripts 1 and 2 of this dissertation both involve the pre-blast detection of trace explosive material. The first manuscript explores the analysis of human hair as an indicator of exposure to explosives. Field analysis of hair for trace explosives is quick and non-invasive, and could prove to be a powerful linkage to physical evidence in the form of bulk explosive material. Individuals tested were involved in studies which required handling or close proximity to bulk high explosives such as TNT, PETN, and RDX. The second manuscript reports the results of research in the design and application of canine training aids for non-traditional, peroxide-based explosives. Organic peroxides such as triacetonetriperoxide (TATP) and hexamethylenetriperoxidediamine (HMTD) can be synthesized relatively easily with store-bought ingredients and have become popular improvised explosives with many terrorist groups. Due to the hazards of handling such sensitive compounds, this research established methods for preparing training aids which contained safe quantities of TATP and HMTD for use in imprinting canines with their characteristic odor. Manuscripts 3 and 4 of this dissertation focus on research conducted to characterize pipe bombs during and after an explosion (post-blast). Pipe bombs represent a large percentage of domestic devices encountered by law enforcement. The current project has involved the preparation and controlled explosion of over 90 pipe bombs of different configurations in order to obtain data on fragmentation patterns, fragment velocity, blast overpressure, and fragmentation distance. Physical data recorded from the collected fragments, such as mass, size, and thickness, was correlated with the relative power of the initial device. Manuscript 4 explores the microstructural analysis of select pipe bomb fragments. Shock-loading of the pipe steel led to plastic deformation and work hardening in the steel grain structure as evidenced by optical microscopy and microhardness testing respectively.

  13. 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.

  14. 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.

  15. Explosives sensor

    SciTech Connect

    Not Available

    1987-01-01

    A compact and supersensitive device that can rapidly detect minute trace vapors from concealed explosives has been developed by scientists at Oak Ridge National Laboratory (ORNL). The new explosives sensor can detect and chemically identify organic nitrogen-oxygen compounds which are the building blocks of explosives such as TNT, plastiques, and nitroglycerine. The device could be used to scan persons entering airport terminals, nuclear power plants, defense installations, or other sensitive locations, providing greater security against potential terrorism. This device works on a glow discharge principle, and is more specifically called an ''Atmospheric Sampling Glow Discharge Ionization'' (ASGDI) source. The new detector is a highly automated, miniaturized version of research mass spectrometers widely used to trace constituents of chemical mixtures. Detail of this device's construction and advantages are discussed in this paper. 2 figs.

  16. 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)

  17. Explosive Welding of Pipes

    NASA Astrophysics Data System (ADS)

    Burtseva, Olga

    2007-06-01

    For connection by welding it is suggested to use the explosive welding method. This method is rather new. Nevertheless, it has become commonly used among the technological developments. This method can be advantageous (saving material and physical resources) comparing to its statical analogs (electron-beam welding, argon-arc welding, plasma welding, gas welding, etc.), in particular, in hard-to-reach areas due to their geographic and climatic conditions. The suggestion is to use water as filler. The principle of non-compressibility of liquid under quasi-dynamic loading is used. In one-dimensional gasdynamic and elastic-plastic calculations we determined non-deformed mass of water (perturbations, which are moving in the axial direction with sound velocity, should not reach the layer end boundaries for 5-7 circulations of shock waves in the radial direction). Linear dimension of the water layer from the zone of pipe coupling along axis in each direction is >= 2R, where R is the internal radius of pipe. Model experiments with pipes having radii R = 57 mm confirmed results of the calculations and the possibility in principle to weld pipes by explosion with use of water as filler. Reduction of pipe diameter after dynamic loading and explosive welding was ˜2%.

  18. Explosive Welding of Pipes

    NASA Astrophysics Data System (ADS)

    Drennov, Oleg; Drennov, Andrey; Burtseva, Olga

    2013-06-01

    For connection by welding it is suggested to use the explosive welding method. This method is rather new. Nevertheless, it has become commonly used among the technological developments. This method can be advantageous (saving material and physical resources) comparing to its statical analogs (electron-beam welding, argon-arc welding, plasma welding, gas welding, etc.), in particular, in hard-to-reach areas due to their geographic and climatic conditions. Explosive welding of cylindrical surfaces is performed by launching of welded layer along longitudinal axis of construction. During this procedure, it is required to provide reliable resistance against radial convergent strains. The traditional method is application of fillers of pipe cavity, which are dense cylindrical objects having special designs. However, when connecting pipes consecutively in pipelines by explosive welding, removal of the fillers becomes difficult and sometimes impossible. The suggestion is to use water as filler. The principle of non-compressibility of liquid under quasi-dynamic loading is used. In one-dimensional gasdynamic and elastic-plastic calculations we determined non-deformed mass of water (perturbations, which are moving in the axial direction with sound velocity, should not reach the layer end boundaries for 5-7 circulations of shock waves in the radial direction). Linear dimension of the water layer from the zone of pipe coupling along axis in each direction is >= 2R, where R is the internal radius of pipe.

  19. Mesoscale Mechanics of Plastic Bonded Explosives

    NASA Astrophysics Data System (ADS)

    Roessig, Keith M.

    2002-07-01

    The dynamic behavior of particulate materials is important to a wide range of problems. When dealing with energetic particulate materials, mechanical ignition is an added concern for safety and performance issues. Micrographs from unconfined impact tests show specific crystal damage paths within the matrix. Under loading conditions consistent with real world applications, these materials can be subjected to large hydrostatic pressures combined with shear deformation. Subsequent stress chain formation concentrates the compressive load into small regions, providing ignition sites within the material. A photoelastic experiment with high speed photography has been constructed to record stress state formation within PMMA disks set in different binder systems. The propagation of shear stress across disk/binder interfaces is shown to be important in the overall stress state of the particle bed. Binders with similar mechanical and acoustic properties as the PMMA disks remove stress concentrations and allow waves to propagate as if in a continuum. Softer binder with lower acoustical wave speeds and hard binders that have debonded from the disks do not allow shear stresses to be transferred. These configurations cause stress concentrations similar to a binderless system of disks.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. FLP-FRT-Based Method To Obtain Unmarked Deletions of CHU_3237 (porU) and Large Genomic Fragments of Cytophaga hutchinsonii

    PubMed Central

    Wang, Ying; Wang, Zhiquan; Cao, Jing; Guan, Zhiwei

    2014-01-01

    Cytophaga hutchinsonii is a widely distributed cellulolytic bacterium in the phylum Bacteroidetes. It can digest crystalline cellulose rapidly without free cellulases or cellulosomes. The mechanism of its cellulose utilization remains a mystery. We developed an efficient method based on a linear DNA double-crossover and FLP-FRT recombination system to obtain unmarked deletions of both single genes and large genomic fragments in C. hutchinsonii. Unmarked deletion of CHU_3237 (porU), an ortholog of the C-terminal signal peptidase of a type IX secretion system (T9SS), resulted in defects in colony spreading, cellulose degradation, and protein secretion, indicating that it is a component of the T9SS and that T9SS plays an important role in cellulose degradation by C. hutchinsonii. Furthermore, deletions of four large genomic fragments were obtained using our method, and the sizes of the excised fragments varied from 9 to 19 kb, spanning from 6 to 22 genes. The customized FLP-FRT method provides an efficient tool for more rapid progress in the cellulose degradation mechanism and other physiological aspects of C. hutchinsonii. PMID:25063660

  5. Insensitive explosive composition of halogenated copolymer and triaminotrinitrobenzene

    DOEpatents

    Benziger, Theodore M.

    1976-01-01

    A highly insensitive and heat resistant plastic-bonded explosive containing 90 wt % triaminotrinitrobenzene and 10 wt % of a fully saturated copolymer of chlorotrifluoroethylene and vinylidene fluoride is readily manufactured by the slurry process.

  6. Explosion risks from nanomaterials

    NASA Astrophysics Data System (ADS)

    Bouillard, Jacques; Vignes, Alexis; Dufaud, Olivier; Perrin, Laurent; Thomas, Dominique

    2009-05-01

    Emerging nanomanufactured products are being incorporated in a variety of consumer products ranging from closer body contact products (i.e. cosmetics, sunscreens, toothpastes, pharmaceuticals, clothing) to more remote body-contact products (electronics, plastics, tires, automotive and aeronautical), hence posing potential health and environmental risks. The new field of nanosafety has emerged and needs to be explored now rather than after problems becomes so ubiquitous and difficult to treat that their trend become irreversible. Such endeavour necessitates a transdisciplinary approach. A commonly forgotten and/or misunderstood risk is that of explosion/detonation of nanopowders, due to their high specific active surface areas. Such risk is emphasized and illustrated with the present development of an appropriate risk analysis. For this particular risk, a review of characterization methods and their limitations with regard to nanopowders is presented and illustrated for a few organic and metallic nanopowders.

  7. Plastic Jellyfish.

    ERIC Educational Resources Information Center

    Moseley, Christine

    2000-01-01

    Presents an environmental science activity designed to enhance students' awareness of the hazards of plastic waste for wildlife in aquatic environments. Discusses how students can take steps to reduce the effects of plastic waste. (WRM)

  8. The Use of Complementary GPR Surveys with Different Grid Spacing to Locate Unmarked Graves in a 19th Century Cemetery in Selinsgrove PA

    NASA Astrophysics Data System (ADS)

    Lachhab, A.; Zawacki, A.

    2014-12-01

    Ground-penetrating radar (GPR) is a geophysical survey tool with many archaeological applications, including the search for graves. A 400 megahertz GPR was employed to locate unmarked graves and buried headstones in a neglected Pennsylvania cemetery dating from the 19th century. The site was initially scanned using a grid pattern with 50cm transect spacings. A smaller site within the cemetery was then selected and scanned at a higher 'resolution,' using smaller transect spacings, to determine whether this improved the accuracy of the findings. Supplementary perpendicular transects were also added. A number of potential sources of error were identified and their consequences were outlined. Short transects with small spacings were found to significantly improve the quality of the obtained data, as was the addition of perpendicular transects. The results are applicable to the search for graves and, more broadly, the use of GPR to identify and locate other subsurface features.

  9. Isolator fragmentation and explosive initiation tests

    SciTech Connect

    Dickson, Peter; Rae, Philip John; Foley, Timothy J.; Novak, Alan M.; Armstrong, Christopher Lee; Baca, Eva V.; Gunderson, Jake Alfred

    2015-09-30

    Three tests were conducted to evaluate the effects of firing an isolator in proximity to a barrier or explosive charge. The tests with explosive were conducted without barrier, on the basis that since any barrier will reduce the shock transmitted to the explosive, bare explosive represents the worst-case from an inadvertent initiation perspective. No reaction was observed. The shock caused by the impact of a representative plastic material on both bare and cased PBX9501 is calculated in the worst-case, 1-D limit, and the known shock response of the HE is used to estimate minimum run-to-detonation lengths. The estimates demonstrate that even 1-D impacts would not be of concern and that, accordingly, the divergent shocks due to isolator fragment impact are of no concern as initiating stimuli.

  10. Chromospheric explosions

    NASA Technical Reports Server (NTRS)

    Doschek, G. A.; theory. (3) Resolved: Most chromospheric h; theory. (3) Resolved: Most chromospheric h

    1986-01-01

    Three issues relative to chromospheric explosions were debated. (1) Resolved: The blue-shifted components of x-ray spectral lines are signatures of chromospheric evaporation. It was concluded that the plasma rising with the corona is indeed the primary source of thermal plasma observed in the corona during flares. (2) Resolved: The excess line broading of UV and X-ray lines is accounted for by a convective velocity distribution in evaporation. It is concluded that the hypothesis that convective evaporation produces the observed X-ray line widths in flares is no more than a hypothesis. It is not supported by any self-consistent physical theory. (3) Resolved: Most chromospheric heating is driven by electron beams. Although it is possible to cast doubt on many lines of evidence for electron beams in the chromosphere, a balanced view that debaters on both sides of the question might agree to is that electron beams probably heat the low corona and upper chromosphere, but their direct impact on evaporating the chromosphere is energetically unimportant when compared to conduction. This represents a major departure from the thick-target flare models that were popular before the Workshop.

  11. 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.

  12. Method for digesting a nitro-bearing explosive compound

    DOEpatents

    Shah, Manish M.

    2000-01-01

    The present invention is a process wherein superoxide radicals from superoxide salt are used to break down the explosive compounds. The process has an excellent reaction rate for degrading explosives, and operates at ambient temperature and atmospheric pressure in aqueous or non-aqueous conditions. Because the superoxide molecules are small, much smaller than an enzyme molecule for example, they can penetrate the microstructure of plastic explosives faster. The superoxide salt generates reactive hydroxyl radicals, which can destroy other organic contaminants, if necessary, along with digesting the explosive nitro-bearing compound.

  13. Ammonium nitrate explosive systems

    DOEpatents

    Stinecipher, Mary M.; Coburn, Michael D.

    1981-01-01

    Novel explosives which comprise mixtures of ammonium nitrate and an ammonium salt of a nitroazole in desired ratios are disclosed. A preferred nitroazole is 3,5-dinitro-1,2,4-triazole. The explosive and physical properties of these explosives may readily be varied by the addition of other explosives and oxidizers. Certain of these mixtures have been found to act as ideal explosives.

  14. 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.

  15. 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).

  16. Totally confined explosive welding

    NASA Technical Reports Server (NTRS)

    Bement, L. J. (Inventor)

    1978-01-01

    The undesirable by-products of explosive welding are confined and the association noise is reduced by the use of a simple enclosure into which the explosive is placed and in which the explosion occurs. An infrangible enclosure is removably attached to one of the members to be bonded at the point directly opposite the bond area. An explosive is completely confined within the enclosure at a point in close proximity to the member to be bonded and a detonating means is attached to the explosive. The balance of the enclosure, not occupied by explosive, is filled with a shaped material which directs the explosive pressure toward the bond area. A detonator adaptor controls the expansion of the enclosure by the explosive force so that the enclosure at no point experiences a discontinuity in expansion which causes rupture. The use of the technique is practical in the restricted area of a space station.

  17. Inspection tester for explosives

    DOEpatents

    Haas, Jeffrey S.; Simpson, Randall L.; Satcher, Joe H.

    2007-11-13

    An inspection tester that can be used anywhere as a primary screening tool by non-technical personnel to determine whether a surface contains explosives. It includes a body with a sample pad. First and second explosives detecting reagent holders and dispensers are operatively connected to the body and the sample pad. The first and second explosives detecting reagent holders and dispensers are positioned to deliver the explosives detecting reagents to the sample pad. A is heater operatively connected to the sample pad.

  18. Inspection tester for explosives

    DOEpatents

    Haas, Jeffrey S.; Simpson, Randall L.; Satcher, Joe H.

    2010-10-05

    An inspection tester that can be used anywhere as a primary screening tool by non-technical personnel to determine whether a surface contains explosives. It includes a body with a sample pad. First and second explosives detecting reagent holders and dispensers are operatively connected to the body and the sample pad. The first and second explosives detecting reagent holders and dispensers are positioned to deliver the explosives detecting reagents to the sample pad. A is heater operatively connected to the sample pad.

  19. Evaluation of Protection Afforded by Brucella abortus and Brucella melitensis Unmarked Deletion Mutants Exhibiting Different Rates of Clearance in BALB/c Mice

    PubMed Central

    Kahl-McDonagh, M. M.; Ficht, T. A.

    2006-01-01

    Research for novel Brucella vaccines has focused upon the development of live vaccine strains, which have proven more efficacious than killed or subunit vaccines. In an effort to develop improved vaccines, signature-tagged mutant banks were screened to identify mutants attenuated for survival. Mutants selected from these screens exhibited various degrees of attenuation characterized by the rate of clearance, ranging from a failure to grow in macrophages after 24 h of infection to a failure to persist in the mouse model beyond 8 weeks. Ideal vaccine candidates should be safe to the host, while evoking protective immunity. In the present work, we constructed unmarked deletion mutants of three gene candidates, manBA, virB2, and asp24, in both Brucella abortus and Brucella melitensis. The Δasp24 mutants, which persist for extended periods in vivo, are superior to current vaccine strains and to other deletion strains tested in the mouse model against homologous challenge infection after 12, 16, and 20 weeks postvaccination. The Δasp24 mutants also display superior protection compared to ΔmanBA and ΔvirB2 mutants against heterologous challenge in mice. From this study, a direct association between protection against infection and cytokine response was not apparent between all vaccine groups and, therefore, correlates of protective immunity will need to be considered further. A distinct correlation between persistence of the vaccine strain and protection against infection was corroborated. PMID:16790778

  20. Mapping anthropogenic fill with GPR for unmarked grave detection: a case study from a possible location of Mokare's grave, Albany, Western Australia

    NASA Astrophysics Data System (ADS)

    Bladon, Paul; Moffat, Ian; Guilfoyle, David; Beale, Alice; Milani, Jennifer

    2011-11-01

    Geophysical techniques are a commonly used, non-invasive method for the location of unmarked graves. Contrary to popular perception, most studies rely not on directly imaging skeletal material but instead on locating the subsurface disturbance created by grave digging. This approach is effective only when sufficient contrast exists between detectable properties (such as structure, mineralogy or porosity) of the grave fill and the surrounding sediment. Resolving these features can be particularly problematic in disturbed areas where other anthropogenic fill is in place, as it is often complex in character and lacks a natural stratigraphy. In many cultural heritage projects, it is often more important to ensure that burials are not disturbed rather than to specifically locate them. Under these circumstances, ground penetrating radar (GPR) can be used to locate modern anthropogenic fill. This may show which areas of the site are younger than the targeted graves and therefore of no archaeological interest. This approach is trialled on a site thought to contain the grave of Mokare, a significant historical figure in the colonial settlement of the Albany area in Western Australia. The delineation of a package of modern fill in the shallow subsurface in the context of the probable history of earthworks on the site demonstrates that Mokare is not buried in the surveyed location. This approach, applied to suitable sites, could contribute to culturally sensitive non-invasive investigation of burial sites in other locations.

  1. Terahertz reflection spectroscopy for the detection of explosives

    NASA Astrophysics Data System (ADS)

    Leahy-Hoppa, Megan R.; Fitch, Michael J.; Osiander, Robert

    2008-02-01

    Terahertz (THz) technology has been demonstrated as a promising tool for detection of explosives and is being developed for aviation screening and sensing of improvised explosive devices. THz radiation is attractive for many applications due to its ability to penetrate through a wide range of dielectric materials including clothing, paper, cardboard, plastics, and wood. Of course, metals block THz waves as is the case for microwave, IR, and visible light. Our work has involved investigating the reflection spectroscopy of a variety of materials including explosives such as RDX and PETN, plastic explosive taggants such as DMDNB, and other organic materials. We have also investigated the changes of the reflection spectra in varying grades of sucrose. Spectral differences are observed between three grades of crystalline sugar in the region from 0.1 to 1 THz. By exploiting the unique spectral features, the discrimination capabilities of THz reflection spectroscopy points to the broad applicability of identifying a wide variety of materials.

  2. EPDM plasticizers

    SciTech Connect

    Godail, M.J.

    1983-08-01

    The properties of paraffinic, naphthenic, and aromatic extender oils used as EPDM plasticizers are discussed in detail. Particular attention is given to viscosity, volatility, specific gravity, and aromatic content.

  3. Detection of explosives by olfactory sensory neurons.

    PubMed

    Corcelli, Angela; Lobasso, Simona; Lopalco, Patrizia; Dibattista, Michele; Araneda, Ricardo; Peterlin, Zita; Firestein, Stuart

    2010-03-15

    The response of olfactory sensory neurons to TNT and RDX as well as to some volatile organic compounds present in the vapors of antipersonnel landmines has been studied both in the pig and in the rat. GC/MS analyses of different plastic components of six different kinds of landmines were performed in order to identify the components of the "perfume" of mines. Studies on rat olfactory mucosa were carried out with electro-olfactogram and calcium imaging techniques, while changes in the cyclic adenosine monophosphate (cAMP) levels following exposure to odorants and explosives were used as a criterion to evaluate the interaction of TNT and RDX with olfactory receptors in a preparation of isolated pig olfactory cilia. These studies indicate that chemical compounds associated with explosives and explosive devices can activate mammalian olfactory receptors. PMID:19913995

  4. Explosion proofing the ``explosion proof`` vacuum cleaner

    SciTech Connect

    Jones, R.D.; Chen, K.C.; Holmes, S.W.

    1995-07-01

    Because of the low humidity environments required in the fabrication of nuclear explosives, assembly technicians can be charged to tens of kilovolts while operating, for example, compressed air, venturi-type, `explosion proof` vacuum cleaners. Nuclear explosives must be isolated from all sources of, and return paths for, AC power and from any part of the lightning protection system. This requirement precludes the use of static ground conductors to drain any charge accumulations. Accordingly, an experimental study of the basic charging mechanisms associated with vacuum operations were identified, the charge generation efficacies of various commercial cleaners were established, and a simple method for neutralizing the charge was devised.

  5. 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 ?m. 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.

  6. Plastic condoms.

    PubMed

    1968-01-01

    Only simple equipment, simple technology and low initial capital investment are needed in their manufacture. The condoms can be made by people who were previously unskilled or only semi-skilled workers. Plastic condoms differ from those made of latex rubber in that the nature of the plastic film allows unlimited shelf-life. Also, the plastic has a higher degree of lubricity than latex rubber; if there is a demand for extra lubrication in a particular market, this can be provided. Because the plastic is inert, these condoms need not be packaged in hermetically sealed containers. All these attributes make it possible to put these condoms on the distributors' shelves in developing countries competitively with rubber condoms. The shape of the plastic condom is based on that of the lamb caecum, which has long been used as luxury-type condom. The plastic condom is made from plastic film (ethylene ethyl acrilate) of 0.001 inch (0.0254 mm.) thickness. In addition, a rubber ring is provided and sealed into the base of the condom for retention during coitus. The advantage of the plastic condom design and the equipment on which it is made is that production can be carried out either in labour-intensive economy or with varying degrees of mechanization and automation. The uniform, finished condom if made using previously untrained workers. Training of workers can be done in a matter of hours on the two machines which are needed to produce and test the condoms. The plastic film is provided on a double wound roll, and condom blanks are prepared by means of a heat-sealing die on the stamping machine. The rubber rings are united to the condom blanks on an assembly machine, which consists of a mandrel and heat-sealing equipment to seal the rubber ring to the base of the condom. Built into the assembly machine is a simple air-testing apparatus that can detect the smallest pinhole flaw in a condom. The manufacturing process is completed by unravelling the condom from the assembly mandrel. The condom is then ready for packaging, either on automatic equipment or manually into small envelopes of highly polished paper. Although their present design is based on a heat-sealed blank, it may be possible shortly to manufacture plastic condoms on the same principle as rubber ones. A dipping process would be used, but with less sophisticated technology and with higher outputs per increment of capital investment. The present equipment used to make plastic condoms cost about 3,000 for one stamping machine and 22 assembly and testing machines. On a three shift per day, 300-day working year, it is possible, with experienced workers, to make 100,000 gross of plastic condoms for each manufacturing unit annually. As the technology is refined, the output should improve significantly. PMID:12155569

  7. Method of digesting an explosive nitro compound

    DOEpatents

    Shah, Manish M.

    2000-01-01

    The present invention is a process wherein bleaching oxidants are used to digest explosive nitro compounds. The process has an excellent reaction rate for digesting explosives and operates under multivariate conditions. Reaction solutions may be aqueous, non-aqueous or a combination thereof, and can also be any pH, but preferably have a pH between 2 and 9. The temperature may be ambient as well as any temperature above which freezing of the solution would occur and below which any degradation of the bleaching oxidant would occur or below which any explosive reaction would be initiated. The pressure may be any pressure, but is preferably ambient or atmospheric, or a pressure above a vapor pressure of the aqueous solution to avoid boiling of the solution. Because the bleaching oxidant molecules are small, much smaller than an enzyme molecule for example, they can penetrate the microstructure of plastic explosives faster. The bleaching oxidants generate reactive hydroxyl radicals, which can destroy other organic contaminants, if necessary, along with digesting the explosive nitro compound.

  8. Shock Analysis of Water Backed Perforated Plate Subjected to Underwater Explosion

    NASA Astrophysics Data System (ADS)

    Nandagopan, Obla Ramanandam; Ranjithkumar, Santharam; Nandakumar, Chirayil Gopalakrishnannair

    2016-03-01

    Perforated plates are essential structural components of sonar acoustic domes of the submarines and underwater platforms. The sonar acoustic domes are considered as `water backed condition' for structural analysis. It is of utmost importance to study the structural response of sonar acoustic domes subjected to noncontact underwater explosion since it has wide scope in defence application. It is intended to investigate the free field pressure due to the underwater explosion and structural response of perforated plate using ANSYS LS-DYNA software for plastic explosive kirkee (PEK), Tri Nitro Toluene (TNT) and Composition 4 explosives. The free field pressure from TNT explosion is validated with the Cole's expression available for this explosive. The time history plots for free field pressure, displacement and principal stress are plotted for all the three explosives. The free field pressure is validated with Cole's formula and found 18 % variation for TNT and 14 % for PEK explosive.

  9. "Fooling fido"--chemical and behavioral studies of pseudo-explosive canine training aids.

    PubMed

    Kranz, William D; Strange, Nicholas A; Goodpaster, John V

    2014-12-01

    Genuine explosive materials are traditionally employed in the training and testing of explosive-detecting canines so that they will respond reliably to these substances. However, challenges arising from the acquisition, storage, handling, and transportation of explosives have given rise to the development of "pseudo-explosive" training aids. These products attempt to emulate the odor of real explosives while remaining inert. Therefore, a canine trained on a pseudo-explosive should respond to its real-life analog. Similarly, a canine trained on an actual explosive should respond to the pseudo-explosive as if it was real. This research tested those assumptions with a focus on three explosives: single-base smokeless powder, 2,4,6-trinitrotoluene (TNT), and a RDX-based plastic explosive (Composition C-4). Using gas chromatography-mass spectrometry with solid phase microextraction as a pre-concentration technique, we determined that the volatile compounds given off by pseudo-explosive products consisted of various solvents, known additives from explosive formulations, and common impurities present in authentic explosives. For example, simulated smokeless powders emitted terpenes, 2,4-dinitrotoluene, diphenylamine, and ethyl centralite. Simulated TNT products emitted 2,4- and 2,6-dinitrotoluene. Simulated C-4 products emitted cyclohexanone, 2-ethyl-1-hexanol, and dimethyldinitrobutane. We also conducted tests to determine whether canines trained on pseudo-explosives are capable of alerting to genuine explosives and vice versa. The results show that canines trained on pseudo-explosives performed poorly at detecting all but the pseudo-explosives they are trained on. Similarly, canines trained on actual explosives performed poorly at detecting all but the actual explosives on which they were trained. PMID:25424725

  10. Explosives tester with heater

    DOEpatents

    Del Eckels, Joel; Nunes, Peter J.; Simpson, Randall L.; Whipple, Richard E.; Carter, J. Chance; Reynolds, John G.

    2010-08-10

    An inspection tester system for testing for explosives. The tester includes a body and a swab unit adapted to be removeably connected to the body. At least one reagent holder and dispenser is operatively connected to the body. The reagent holder and dispenser contains an explosives detecting reagent and is positioned to deliver the explosives detecting reagent to the swab unit. A heater is operatively connected to the body and the swab unit is adapted to be operatively connected to the heater.

  11. Free radical explosive composition

    DOEpatents

    Walker, Franklin E.; Wasley, Richard J.

    1979-01-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a getter additive comprising a compound or mixture of compounds capable of capturing or deactivating free radicals or ions under mechanical or electrical shock conditions and which is not an explosive. Exemplary getter additives are isocyanates, olefins and iodine.

  12. Plastics Technician.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This document contains 16 units to consider for use in a tech prep competency profile for the occupation of plastics technician. All the units listed will not necessarily apply to every situation or tech prep consortium, nor will all the competencies within each unit be appropriate. Several units appear within each specific occupation and would…

  13. Cosmetic Plastic Surgery Statistics

    MedlinePlus

    2014 Cosmetic Plastic Surgery Statistics Cosmetic Procedure Trends 2014 Plastic Surgery Statistics Report Please credit the AMERICAN SOCIETY OF PLASTIC SURGEONS when citing statistical data or using ...

  14. Los Alamos explosives performance data

    SciTech Connect

    Mader, C.L.; Crane, S.L.; Johnson, J.N.

    1983-01-01

    This book provides explosives performances, as measured by plate acceleration data, aquarium data, and detonation velocity data. It includes some 800 pages of data and is for explosives scientists more than engineers. (This is a companion volume to the 1980 ''LASL Explosive Property Data'' which covered only pure explosives and well-characterized explosive formulations).

  15. 49 CFR Appendix D to Part 173 - Test Methods for Dynamite (Explosive, Blasting, Type A)

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Test Methods for Dynamite (Explosive, Blasting...—Test Methods for Dynamite (Explosive, Blasting, Type A) 1. Test method D-1—Leakage Test A wooden stick... ends open, and is assembled in the following manner: (a) Close the bottom with a plastic plug...

  16. The development of an inert simulant for HNS/teflon explosive

    NASA Technical Reports Server (NTRS)

    Elban, W. L.

    1972-01-01

    The report describes the development and evaluation of an inert simulant for the thermally stable, heat-resistant plastic-bonded explosive HNS/Teflon. The simulant is made by dry blending vinylidene fluoride, melamine and Teflon which when compared has a pressed density and thermal properties corresponding closely to the explosive. In addition, the machinability and handling characteristics of the simulant are similar to the explosive.

  17. Cell phone explosion.

    PubMed

    Atreya, Alok; Kanchan, Tanuj; Nepal, Samata; Pandey, Bhuwan Raj

    2016-03-01

    Cell phone explosions and resultant burn injuries are rarely reported in the scientific literature. We report a case of cell phone explosion that occurred when a young male was listening to music while the mobile was plugged in for charging. PMID:26427492

  18. Explosively pumped laser light

    DOEpatents

    Piltch, Martin S. (Los Alamos, NM); Michelotti, Roy A. (Los Alamos, NM)

    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.

  19. Detection of explosives with laser-induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Wang, Qian-Qian; Liu, Kai; Zhao, Hua; Ge, Cong-Hui; Huang, Zhi-Wen

    2012-12-01

    Our recent work on the detection of explosives by laser-induced breakdown spectroscopy (LIBS) is reviewed in this paper. We have studied the physical mechanism of laser-induced plasma of an organic explosive, TNT. The LIBS spectra of TNT under single-photon excitation are simulated using MATLAB. The variations of the atomic emission lines intensities of carbon, hydrogen, oxygen, and nitrogen versus the plasma temperature are simulated too. We also investigate the time-resolved LIBS spectra of a common inorganic explosive, black powder, in two kinds of surrounding atmospheres, air and argon, and find that the maximum value of the O atomic emission line SBR of black powder occurs at a gate delay of 596 ns. Another focus of our work is on using chemometic methods such as principle component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) to distinguish the organic explosives from organic materials such as plastics. A PLS-DA model for classification is built. TNT and seven types of plastics are chosen as samples to test the model. The experimental results demonstrate that LIBS coupled with the chemometric techniques has the capacity to discriminate organic explosive from plastics.

  20. Supercritical Solubility of Binders Used in Explosive Formulations, Final Report

    SciTech Connect

    David A. Bell

    2002-12-18

    In-situ ultraviolet spectroscopy was used to measure the dissolution of polymers in supercritical carbon dioxide. Absorbance versus time data were taken to obtain both solubilities and diffusion coefficients. The tested polymers were potential binders for plastic-bonded explosives.

  1. Explosives detection with quadrupole resonance analysis

    NASA Astrophysics Data System (ADS)

    Rayner, Timothy J.; Thorson, Benjamin D.; Beevor, Simon; West, Rebecca; Krauss, Ronald A.

    1997-02-01

    The increase in international terrorist activity over the past decade has necessitated the exploration of new technologies for the detection of plastic explosives. Quadrupole resonance analysis (QRA) has proven effective as a technique for detecting the presence of plastic, sheet, and military explosive compounds in small quantities, and can also be used to identify narcotics such as heroin and cocaine base. QRA is similar to the widely used magnetic resonance (MR) and magnetic resonance imaging (MRI) techniques, but has the considerable advantage that the item being inspected does not need to be immersed in a steady, homogeneous magnetic field. The target compounds are conclusively identified by their unique quadrupole resonance frequencies. Quantum magnetics has develop and introduced a product line of explosives and narcotics detection devices based upon QRA technology. The work presented here concerns a multi-compound QRA detection system designed to screen checked baggage, cargo, and sacks of mail at airports and other high-security facilities. The design philosophy and performance are discussed and supported by test results from field trials conducted in the United States and the United Kingdom. This detection system represents the current state of QRA technology for field use in both commercial and government sectors.

  2. 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.

  3. 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.

  4. Photochromic plastics

    SciTech Connect

    Chu, N.Y.C.

    1990-12-31

    The benefits of photochromic glazing materials as well as other switchable devices for solar control and/or use have been analyzed. The analysis indicates that the saving in cooling costs may be significant for a commercial building. This saving can be further increased if other solar control technologies which operate in the solar spectra region outside the visible range are integrated with photochromic property. Photochromic plastics have the advantage of readiness to integrate with other solar control technologies as in the case of retrofit polyester film. The glazing applications of spirooxazines have only been considered recently. The few examples described in the preceding section are just exploratory. Improvements in photochromic performance and durability are definitely probable as more spirooxazine compounds and formulations are tested and stabilization methods are discovered. Recently, an all plastic model house was constructed by General Electric in which both photochromic and electrochromic switchable windows were employed. Thus, commercialization of photochromic plastics for glazing applications may not be as remote as it was not too long ago. 66 refs., 4 figs., 1 tab.

  5. 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.

  6. Explosive acceleration of plates using nonconventional explosives heavily loaded with inert and reactive materials

    NASA Astrophysics Data System (ADS)

    Loiseau, Jason; Petel, Oren; Huneault, Justin; Serge, Matthew; Frost, David; Higgins, Andrew

    2013-06-01

    The detonation behavior of high explosives containing dispersed quantities or packed beds of dense additives has been previously investigated with the observation that such systems depart from the ``gamma law'' behavior typical of homogeneous explosives due to momentum transfer and thermalization between particles and detonation products. However, the influence of this non-ideal detonation behavior on the divergence speed of plates has been far less rigorously studied and existing literature suggests that the effect of dense additives cannot be explained solely through the straightforward application of the Gurney method with energy and density averaging of the explosive. In the current study, the acceleration history and terminal velocity of aluminum flyers launched by packed beds of granular material saturated by amine-sensitized nitromethane is reported. Two experimental configurations are used to study acceleration either by a purely grazing detonation in a finite thickness slab of explosive or by a normal detonation from an effectively infinite thickness of explosive. Flyer acceleration and velocity is measured via Photonic Doppler Velocimetry. Packed beds of plastic, aluminum, glass, iron, and bismuth are considered and the data is compared to Gurney velocity predictions.

  7. Lithium niobate explosion monitor

    DOEpatents

    Bundy, C.H.; Graham, R.A.; Kuehn, S.F.; Precit, R.R.; Rogers, M.S.

    1990-01-09

    Monitoring explosive devices is accomplished with a substantially z-cut lithium niobate crystal in abutment with the explosive device. Upon impact by a shock wave from detonation of the explosive device, the crystal emits a current pulse prior to destruction of the crystal. The current pulse is detected by a current viewing transformer and recorded as a function of time in nanoseconds. In order to self-check the crystal, the crystal has a chromium film resistor deposited thereon which may be heated by a current pulse prior to detonation. This generates a charge which is detected by a charge amplifier. 8 figs.

  8. Lithium niobate explosion monitor

    DOEpatents

    Bundy, Charles H.; Graham, Robert A.; Kuehn, Stephen F.; Precit, Richard R.; Rogers, Michael S.

    1990-01-01

    Monitoring explosive devices is accomplished with a substantially z-cut lithium niobate crystal in abutment with the explosive device. Upon impact by a shock wave from detonation of the explosive device, the crystal emits a current pulse prior to destruction of the crystal. The current pulse is detected by a current viewing transformer and recorded as a function of time in nanoseconds. In order to self-check the crystal, the crystal has a chromium film resistor deposited thereon which may be heated by a current pulse prior to detonation. This generates a charge which is detected by a charge amplifier.

  9. Estimation of point explosion parameters by body-wave spectra

    NASA Astrophysics Data System (ADS)

    Tsereteli, Nino; Kereselidze, Zurab

    2014-05-01

    Radial model of point explosion is presented. According to this model the epicenter are consists with two qualitatively different spherical area. In the first sphere the explosion energy is spent on plastic deformations. The second spherical area, where the medium are elastically, presents area where the body waves are generated. The frequency spectrum of this wave can presents the intrinsic frequency of natural oscillations of the point explosion. The Euler radial equation was used during the modeling of this process. Using analytical equation of discrete frequency spectrum is possible to solve the inverse seismological problem. In other words it is possible to calculate the internal and external radius of elastic area. Finally we can obtain a sufficiently correct analytic solution to define the linear characteristics of the point explosion area and estimating the energy released.

  10. Fast Internal Temperature Measurements in PBX9501 Thermal Explosions

    NASA Astrophysics Data System (ADS)

    Smilowitz, L.; Henson, B. F.; Sandstrom, M. M.; Asay, B. W.; Oschwald, D. M.; Romero, J. J.; Novak, A. M.

    2006-07-01

    We have made spatially and temporally resolved temperature measurements internal to a thermal explosion in PBX9501, which is a plastic bonded explosive composed of 95% HMX and 2.5% estane mixed with 2.5% nitroplasticizer (BDNPA/F). In order to study the evolution of ignition in a thermally treated piece of explosive, we have pushed the time resolution of several different temperature diagnostics. In this paper, we will discuss the details of the time response of these diagnostics including temperature uncertainties. The temperature measurements are made both by thermocouples with corrections applied to compensate for the thermocouple response time and with optical pyrometry. An additional goal of adding high energy radiography diagnostics to future experiments has motivated an effort to synchronize thermal explosions to an external clock. In this paper, I discuss our current capabilities for controlling and measuring the development of an ignition within a piece of heated PBX9501.

  11. Disorder induces explosive synchronization.

    PubMed

    Skardal, Per Sebastian; Arenas, Alex

    2014-06-01

    We study explosive synchronization, a phenomenon characterized by first-order phase transitions between incoherent and synchronized states in networks of coupled oscillators. While explosive synchronization has been the subject of many recent studies, in each case strong conditions on the heterogeneity of the network, its link weights, or its initial construction are imposed to engineer a first-order phase transition. This raises the question of how robust explosive synchronization is in view of more realistic structural and dynamical properties. Here we show that explosive synchronization can be induced in mildly heterogeneous networks by the addition of quenched disorder to the oscillators' frequencies, demonstrating that it is not only robust to, but moreover promoted by, this natural mechanism. We support these findings with numerical and analytical results, presenting simulations of a real neural network as well as a self-consistency theory used to study synthetic networks. PMID:25019837

  12. 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.

  13. Idaho Explosives Detection System

    NASA Astrophysics Data System (ADS)

    Reber, Edward L.; Blackwood, Larry G.; Edwards, Andrew J.; Jewell, J. Keith; Rohde, Kenneth W.; Seabury, Edward H.; Klinger, Jeffery B.

    2005-12-01

    The Idaho Explosives Detection System was developed at the Idaho National Laboratory (INL) to respond to threats imposed by delivery trucks potentially carrying explosives into military bases. A full-scale prototype system has been built and is currently undergoing testing. The system consists of two racks, one on each side of a subject vehicle. Each rack includes a neutron generator and an array of NaI detectors. The two neutron generators are pulsed and synchronized. A laptop computer controls the entire system. The control software is easily operable by minimally trained staff. The system was developed to detect explosives in a medium size truck within a 5-min measurement time. System performance was successfully demonstrated with explosives at the INL in June 2004 and at Andrews Air Force Base in July 2004.

  14. Idaho Explosive Detection System

    SciTech Connect

    Klinger, Jeff

    2011-01-01

    Learn how INL researchers are making the world safer by developing an explosives detection system that can inspect cargo. For more information about INL security research, visit http://www.facebook.com/idahonationallaboratory

  15. Idaho Explosives Detection System

    SciTech Connect

    Edward L. Reber; J. Keith Jewell; Larry G. Blackwood; Andrew J. Edwards; Kenneth W. Rohde; Edward H. Seabury

    2004-10-01

    The Idaho Explosives Detection System (IEDS) was developed at the Idaho National Laboratory (INL) to respond to threats imposed by delivery trucks carrying explosives into military bases. A full-scale prototype system has been built and is currently undergoing testing. The system consists of two racks, one on each side of a subject vehicle. Each rack includes a neutron generator and an array of NaI detectors. The two neutron generators are pulsed and synchronized. A laptop computer controls the entire system. The control software is easily operable by minimally trained staff. The system was developed to detect explosives in a medium size truck within a 5-minute measurement time. System performance was successfully demonstrated with explosives at the INL in June 2004 and at Andrews Air Force Base in July 2004.

  16. Explosion suppression system

    DOEpatents

    Sapko, Michael J.; Cortese, Robert A.

    1992-01-01

    An explosion suppression system and triggering apparatus therefor are provided for quenching gas and dust explosions. An electrically actuated suppression mechanism which dispenses an extinguishing agent into the path ahead of the propagating flame is actuated by a triggering device which is light powered. This triggering device is located upstream of the propagating flame and converts light from the flame to an electrical actuation signal. A pressure arming device electrically connects the triggering device to the suppression device only when the explosion is sensed by a further characteristic thereof beside the flame such as the pioneer pressure wave. The light powered triggering device includes a solar panel which is disposed in the path of the explosion and oriented between horizontally downward and vertical. Testing mechanisms are also preferably provided to test the operation of the solar panel and detonator as well as the pressure arming mechanism.

  17. Modeling nuclear explosion

    NASA Astrophysics Data System (ADS)

    Redd, Jeremy; Panin, Alexander

    2012-10-01

    As a result of the Nuclear Test Ban Treaty, no nuclear explosion tests have been performed by the US since 1992. This appreciably limits valuable experimental data needed for improvement of existing weapons and development of new ones, as well as for use of nuclear devices in non-military applications (such as making underground oil reservoirs or compressed air energy storages). This in turn increases the value of numerical modeling of nuclear explosions and of their effects on the environment. We develop numerical codes simulating fission chain reactions in a supercritical U and Pu core and the dynamics of the subsequent expansion of generated hot plasma in order to better understand the impact of such explosions on their surroundings. The results of our simulations (of both above ground and underground explosions) of various energy yields are presented.

  18. Idaho Explosive Detection System

    ScienceCinema

    Klinger, Jeff

    2013-05-28

    Learn how INL researchers are making the world safer by developing an explosives detection system that can inspect cargo. For more information about INL security research, visit http://www.facebook.com/idahonationallaboratory

  19. Quantified explosives transfer on surfaces for the evaluation of trace detection equipment.

    PubMed

    Tam, Maggie; Pilon, Pierre; Zaknoun, Hafid

    2013-09-01

    Trace explosive test surfaces are often required for the evaluation of trace detection equipment to determine the equipment performance. Test surfaces of C-4, Detasheet, Semtex-H, TNT, and HMTD were prepared by transferring trace amount of explosive deposited on polytetrafluoroethylene (PTFE) transfer strips onto different surfaces (Kraft paper, hard plastic, woven fabric, and soft vinyl). The amount of explosive transferred was deduced from the amount of explosive remaining on the PTFE strips after transfer, as quantified by direct analysis using tandem mass spectrometry with thermal desorption. From the data set of over 2000 transfers, we experienced lower transfer efficiency for Semtex-H and Detasheet, and for soft vinyl and hard plastic. However, the rapid quantification mass spectrometric method allowed the transfer efficiency to be determined for all test surfaces used in an evaluation of trace explosive detectors, thereby permitting only the test surfaces with desired transfer to be accepted for the assessment. PMID:23879631

  20. Volcanic explosion on Io

    NASA Technical Reports Server (NTRS)

    1979-01-01

    VOLCANIC EXPLOSION ON IO: Voyager 1 acquired this image of Io on March 4 at 5:30 p.m. (PST) about 11 hours before closest approach to the Jupiter moon. The distance to Io was about 490,000 kilometers (304,000 miles). An enormous volcanic explosion can be seen silhouetted against dark space over Io's bright limb. The brightness of the plume has been increased by the computer as it is normally extremely faint, whereas the relative color of the plume (greenish white) has been preserved. At this time solid material had been thrown up to an altitude of about 100 miles. This requires an ejection velocity from the volcanic vent of about 1200 miles per hour, material reaching the crest of the fountain in several minutes. The vent area is a complex circular structure consisting of a bright ring about 300 kilometers in diameter and a central region of irregular dark and light patterns. Volcanic explosions similar to this occur on the Earth when magmatic gases expand explosively as material is vented. On Earth water is the major gas driving the explosion. Because Io is thought to be extremely dry, scientists are searching for other gases to explain the explosion. JPL manages and controls the Voyager Project for NASA's Office of Space Science.

  1. 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.

  2. Direct real-time detection of vapors from explosive compounds.

    PubMed

    Ewing, Robert G; Clowers, Brian H; Atkinson, David A

    2013-11-19

    The real-time detection of vapors from low volatility explosives including PETN, tetryl, RDX, and nitroglycerine along with various compositions containing these substances was demonstrated. This was accomplished with an atmospheric flow tube (AFT) using a nonradioactive ionization source coupled to a mass spectrometer. Direct vapor detection was accomplished in less than 5 s at ambient temperature without sample preconcentration. The several seconds of residence time of analytes in the AFT provided a significant opportunity for reactant ions to interact with analyte vapors to achieve ionization. This extended reaction time, combined with the selective ionization using the nitrate reactant ions (NO3(-) and NO3(-)·HNO3), enabled highly sensitive explosives detection from explosive vapors present in ambient laboratory air. Observed signals from diluted explosive vapors indicated detection limits below 10 ppqv using selected ion monitoring (SIM) of the explosive-nitrate adduct at m/z 349, 378, 284, and 289 for tetryl, PETN, RDX, and NG, respectively. Also provided is a demonstration of the vapor detection from 10 different energetic formulations sampled in ambient laboratory air, including double base propellants, plastic explosives, and commercial blasting explosives using SIM for the NG, PETN, and RDX product ions. PMID:24090362

  3. 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.

  4. 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.

  5. 49 CFR 172.522 - EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3 placards.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3... INFORMATION, TRAINING REQUIREMENTS, AND SECURITY PLANS Placarding § 172.522 EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3 placards. (a) Except for size and color, the EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES...

  6. 49 CFR 172.522 - EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3 placards.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3... INFORMATION, TRAINING REQUIREMENTS, AND SECURITY PLANS Placarding § 172.522 EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3 placards. (a) Except for size and color, the EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES...

  7. 49 CFR 172.522 - EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3 placards.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3... INFORMATION, TRAINING REQUIREMENTS, AND SECURITY PLANS Placarding § 172.522 EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3 placards. (a) Except for size and color, the EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES...

  8. 49 CFR 172.522 - EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3 placards.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3... INFORMATION, TRAINING REQUIREMENTS, AND SECURITY PLANS Placarding § 172.522 EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES 1.3 placards. (a) Except for size and color, the EXPLOSIVES 1.1, EXPLOSIVES 1.2 and EXPLOSIVES...

  9. Evaluation of EL836 explosive stimulation of Devonian gas shale

    SciTech Connect

    Barbour, T G

    1980-07-01

    This report presents an evaluation of EL836, an explosive developed at E.I. duPont de Nemours and Company Laboratories, in stimulating gas shale. EL836 is a water gel type explosive with a high aluminum content. The computational evaluation of EL836 involved four one-dimensional cyclindrical geometry calculations to assess the influence of two equation-of-state descriptios of EL836, the effect or rock yielding and the effect of internal crack pressurization. Results of a computational evaluation of the EL836 explosive in stimulating Devonian gas shale suggest the following: Extensive plastic yielding will occur in a region immediate to the borehole. Extensive tensile fracture will occur in a region that begins at the outer boundary of plastic deformation and terminates at more than 100 borehole radii. Without a mechanism of ;near-wellbore fracture, such as crushing or pre-cracking during drilling or intentional borehole grooving, the plastic flow that occurs adjacent to the wellbore causes stress redistributions which prohibit early-time (less than a millisecond) tensile fracture immediate to the wellbore and thus prohibits gas penetration from the wellbore into the crack system. The barrier that the near-wellbore plastic zone presents to gas flow from the wellbore is reduced in radial dimension as time increases. Natural fractures in the wellbore wall or cataclysmic deformation and fracture adjacent to the wellbore, as a result of the explosive detonation, will likely assist in breaking down the barrier to gas flow. Very significatn enhancement is achieved in the EL836 stimulation treatment when gases penetrate the stress-wave induced radial cracks. Only minor differences were observed in the EL836 stimulation effects when comparison is made between two different explosive equations-of-state. 33 figures, 2 tables.

  10. Mesoscale thermal-mechanical analysis of shocked induced granular explosives and polymer-bonded explosives

    NASA Astrophysics Data System (ADS)

    Wang, Xinjie; Wu, Yanqing; Huang, Fenglei

    2015-06-01

    The thermal-mechanical response of HMX-based granular explosives (GXs) and polymer-bonded explosives (PBXs) with variable number of crystals from 10 to 100 under impact loading is investigated with finite element software ABAQUS. A series of three dimensional mesoscale calculations are carried out with the crystal plasticity constitutive model for HMX crystals that accounts for nonlinear elasticity and crystalline plasticity and the viscoelastic model for the polymer binder. To make the analysis comparable, the morphology and the size of HMX crystals are kept the same for both GXs and PBXs. In order to quantify the effect of polymer binder under different strain rate, the calculation models are impacted with initial boundary velocities from 10 to 100 m/s. The results shows that the average pressure of PBXs is approximately 50% higher than GXs and that the localized stress and temperature is highly increased with the polymer binder, which indicates the crystal anisotropy as well as the polymer binder plays an important role in influencing the stress and thermal response of HMX crystals. The thermal-mechanical response analyzed here is essential to predict the formation of hot spot and the ignition of explosives.

  11. Plastic Surgery for Teenagers

    MedlinePlus

    ... Surgery for Teenagers Plastic Surgery For Teenagers Briefing Paper Teenagers who want to have plastic surgery usually ... 669-678. Share Related Links Plastic Surgery Briefing Papers Find Your Surgeon Please enter a search Menu ...

  12. 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.

  13. Sub-Nanogram Detection of RDX Explosive by Monoclonal Antibodies.

    PubMed

    Ulaeto, David O; Hutchinson, Alistair P; Nicklin, Stephen

    2015-08-01

    Polyclonal and monoclonal antibodies were raised to protein carrier molecules haptenized with RDX, a major component of many plastic explosives including Semtex. Sera from immunized mice detected RDX protein conjugates in standard ELISA. Clonally purified monoclonal antibodies had detection limits in the sub-ng/mL range for underivatized RDX in competition ELISA. The monoclonal antibodies are not dependent on the presence of taggants added during the manufacturing process, and are likely to have utility in the detection of any explosive containing RDX, or RDX contamination of environmental sites. PMID:26252765

  14. Sub-Nanogram Detection of RDX Explosive by Monoclonal Antibodies

    PubMed Central

    Hutchinson, Alistair P.; Nicklin, Stephen

    2015-01-01

    Polyclonal and monoclonal antibodies were raised to protein carrier molecules haptenized with RDX, a major component of many plastic explosives including Semtex. Sera from immunized mice detected RDX protein conjugates in standard ELISA. Clonally purified monoclonal antibodies had detection limits in the sub-ng/mL range for underivatized RDX in competition ELISA. The monoclonal antibodies are not dependent on the presence of taggants added during the manufacturing process, and are likely to have utility in the detection of any explosive containing RDX, or RDX contamination of environmental sites. PMID:26252765

  15. Shear band formation in plastic bonded explosive (PBX)

    SciTech Connect

    Dey, T.N.; Johnson, J.N.

    1997-07-01

    Adiabatic shear bands can be a source of ignition and lead to detonation. At low to moderate deformation rates, 10-1000/s , two other mechanisms can also give rise to shear bands. These mechanisms are: 1) softening caused by microcracking and 2) a constitutive response with a non-associated flow rule as is observed in granular material such as soil. Brittle behavior at small strains and the granular nature of HMX suggest that PBX-9501 constitutive behavior may be similar to sand. A constitutive model for the first of these mechanisms is studied in a series of calculations. This viscoelastic constitutive model for PBX-9501 softens via a statistical crack model. A sand model is used to provide a non-associated flow rule and detailed results will be reported elsewhere. Both models generate shear band formation at 1-2% strain at nominal strain rates at and below 1000/s. Shear band formation is suppressed at higher strain rates. Both mechanisms may accelerate the formation of adiabatic shear bands.

  16. 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)

  17. Explosive synchronization is discontinuous

    NASA Astrophysics Data System (ADS)

    Vlasov, Vladimir; Zou, Yong; Pereira, Tiago

    2015-07-01

    Spontaneous explosive is an abrupt transition to collective behavior taking place in heterogeneous networks when the frequencies of the nodes are positively correlated with the node degree. This explosive transition was conjectured to be discontinuous. Indeed, numerical investigations reveal a hysteresis behavior associated with the transition. Here, we analyze explosive synchronization in star graphs. We show that in the thermodynamic limit the transition to (and out of) collective behavior is indeed discontinuous. The discontinuous nature of the transition is related to the nonlinear behavior of the order parameter, which in the thermodynamic limit exhibits multiple fixed points. Moreover, we unravel the hysteresis behavior in terms of the graph parameters. Our numerical results show that finite-size graphs are well described by our predictions.

  18. 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.

  19. Bioremediation of explosives

    SciTech Connect

    Unkefer, P.J.; Alvarez, M.A.; Hanners, J.L.; Unkefer, C.J.; Stenger, M.; Margiotta, E.A.

    1990-01-01

    The extensive manufacture, packing, and the use of explosives has often resulted in significant contamination of soils and ground waters near these activities. Congressional mandate has now required that such sites be remediated. An especially promising technology for this explosives problem is biotechnology. When applicable, biotechnology is cheap and provides complete conversion of hazardous compounds to harmless biomass or carbon dioxide. The focus of this paper will be on our present understanding of the microbial metabolism of the explosives, TNT and RDX, which have been used most extensively in the United States. To assure that an efficient process is developed for TNT biodegradation, we are conducting appropriate lab scale tests with TNT contaminated soil. First, we are testing their efficiency in soil/water slurries; we are also testing their efficiency in a column system designed to simulate composting conditions. A pilot scale test of this bacterial degradation will be conducted as soon as weather permits. 36 refs., 5 figs.

  20. Loading of wellbores with explosives

    SciTech Connect

    Loving, F.A.; Simmons, W.J.

    1983-04-26

    Bags of explosive are loaded rapidly into deep wellbores by suspending a rigid positioning tube partway into the wellbore, and loading the bags into the tube, the bags being prevented from dropping through the open bottom end of the tube by a cord attached to the lowermost bag and secured at the upper end of the tube when the tube-suspending cable is in tension by a cordsecuring/releasing means, E.G., a pivotable bar having a hook on one end. When the bag-laden tube is lowered to the bottom of the wellbore, or to a column of bags previously placed therein, the tension on the cable is relaxed and the cord is released, allowing the positioning tube thereafter to be raised to the surface for re-use, leaving the cord and bags in the wellbore. Freedom of the bag-supporting cord to move with respect to the positioning tube when the latter is raised to the surface is assured by threading the cord through plastic tubing mounted to the wall of the positioning tube and releasable therefrom for reuse.

  1. An explosion in Tunguska

    NASA Astrophysics Data System (ADS)

    Nistor, Ioan

    A detailed History of exploration of the place at Podkamennaya Tunguska, where a well known explosion has occured on 30 June 1908 is given with emphasys on the role by Leonid Kulik (1928-29). A short biography of Leonid Kulik is given. A review of subsequent expeditions is given. A review of existing theories concerning the explosion at Podkamennaya Tunguska on 30 June 1908 is given, including that of a meteor impact, asteroid impact, atomic explosion (F. Zigel and other), comet impact (V.G. Fesenkov and other). The theory sustained by author is that of a methan gas explosion initialazed by a meteor in a volume of about 0.25-2.5 billions m3 of methan. The shape of the place could be explained by few gaseous pouches, which could explode in a chain reaction. A review of similar explosions on the level of ground is given in the USSR as well as elsewhere. The soil fluidization is reviewed during earthquakes and similar phenomena. The original hypothesis by author was published in the "Lumea" N 41 magazin (Romania) on October 12 1989. The author disagree with atomic hypotesis enounced by F. Zigel, while the main factor of the explosion is the formation of one or few methan pouches above the soil. The programe of one of the most important international workshops (Tunguska 96 in Bologna on July 14-17) is attached. The site by Ioan Nistor gives a collection of informations about the event from elsewhere as well as the "gaseous pouches" hypothesis by the author.

  2. 78 FR 64246 - Commerce in Explosives; List of Explosives Materials

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-28

    ... supersedes the List of Explosives Materials dated September 20, 2012 (Docket No. ATF 47N, 77 FR 58410.... Aluminum containing polymeric propellant. Aluminum ophorite explosive. Amatex. Amatol. Ammonal. Ammonium... (excluding ammonium perchlorate composite propellant (APCP)). Ammonium picrate . Ammonium salt lattice...

  3. Explosive Welding with Nitroguanidine.

    PubMed

    Sadwin, L D

    1964-03-13

    By using the explosive nitroguanidine, continuous welds can be made between similar and dissimilar metals. Since low detonation pressures are attainable, pressure transfer media are not required between the explosive and the metal surface. The need for either a space or an angle between the metals is eliminated, and very low atmospheric pressures are not required. Successful welds have been made between tantalum and 4140 steel, 3003H14 aluminum and 4140 steel, and 304 stainless steel and 3003H14 aluminum. PMID:17833901

  4. Microcantilever detector for explosives

    DOEpatents

    Thundat, T.G.

    1999-06-29

    Methods and apparatus for detecting the presence of explosives by analyzing a vapor sample from the suspect vicinity utilize at least one microcantilever. Explosive gas molecules which have been adsorbed onto the microcantilever are subsequently heated to cause combustion. Heat, along with momentum transfer from combustion, causes bending and a transient resonance response of the microcantilever which may be detected by a laser diode which is focused on the microcantilever and a photodetector which detects deflection of the reflected laser beam caused by heat-induced deflection and resonance response of the microcantilever. 2 figs.

  5. Microcantilever detector for explosives

    DOEpatents

    Thundat, Thomas G.

    1999-01-01

    Methods and apparatus for detecting the presence of explosives by analyzing a vapor sample from the suspect vicinity utilize at least one microcantilever. Explosive gas molecules which have been adsorbed onto the microcantilever are subsequently heated to cause combustion. Heat, along with momentum transfer from combustion, causes bending and a transient resonance response of the microcantilever which may be detected by a laser diode which is focused on the microcantilever and a photodetector which detects deflection of the reflected laser beam caused by heat-induced deflection and resonance response of the microcantilever.

  6. 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 equal to that of hexanitrostilbene (HNS), yet it has a greater CJ pressure and detonation velocity. In an effort to reduce the critical diameter of TATB without sacrificing its insensitivity, we have studied the explosive performances of TATB mixed with DAAzlF (X-0561) and TATB mixed with DAAF (X-0563).

  7. Direct Real-Time Detection of Vapors from Explosive Compounds

    SciTech Connect

    Ewing, Robert G.; Clowers, Brian H.; Atkinson, David A.

    2013-10-03

    The real-time detection of vapors from low volatility explosives including PETN, tetryl, RDX and nitroglycerine along with various compositions containing these substances is demonstrated. This was accomplished with an atmospheric flow tube (AFT) using a non-radioactive ionization source and coupled to a mass spectrometer. Direct vapor detection was demonstrated in less than 5 seconds at ambient temperature without sample pre-concentration. The several seconds of residence time of analytes in the AFT provides a significant opportunity for reactant ions to interact with analyte vapors to achieve ionization. This extended reaction time, combined with the selective ionization using the nitrate reactant ions (NO3- and NO3-•HNO3), enables highly sensitive explosives detection. Observed signals from diluted explosive vapors indicate detection limits below 10 ppqv using selected ion monitoring (SIM) of the explosive-nitrate adduct at m/z 349, 378, 284 and 289 for tetryl, PETN, RDX and NG respectively. Also provided is a demonstration of the vapor detection from 10 different energetic formulations, including double base propellants, plastic explosives and commercial blasting explosives using SIM for the NG, PETN and RDX product ions.

  8. Portable raman explosives detection

    SciTech Connect

    Moore, David Steven; Scharff, Robert J

    2008-01-01

    Recent advances in portable Raman instruments have dramatically increased their application to emergency response and forensics, as well as homeland defense. This paper reviews the relevant attributes and disadvantages of portable Raman spectroscopy, both essentially and instrumentally, to the task of explosives detection in the field.

  9. Managing the data explosion

    USGS Publications Warehouse

    Hooper, Richard P.; Aulenbach, Brent T.

    1993-01-01

    The 'data explosion' brought on by electronic sensors and automatic samplers can strain the capabilities of existing water-quality data-management systems just when they're needed most to process the information. The U.S. Geological Survey has responded to the problem by setting up an innovative system that allows rapid data analysis.

  10. Explosive inventory program

    SciTech Connect

    Lewis, L.A.; Taylor, R.S.

    1990-09-01

    This report describes the computer program used at the Tonopah Test Range to maintain the explosive inventory. The program, which uses dBASE III or dBASE III Plus and runs on an IBM PC or compatible, has the capabilities to update (add or subtract) items, edit or delete, append, and generate various reports.

  11. 75 FR 5545 - Explosives

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-03

    ...In this notice, OSHA is terminating the rulemaking to amend its Explosives and Blasting Agents Standard at 29 CFR 1910.109. OSHA is taking this action because it has limited rulemaking resources, which are currently devoted to higher priority projects that will affect a more significant improvement in worker safety and health than would this...

  12. Portable Raman explosives detection.

    PubMed

    Moore, David S; Scharff, R Jason

    2009-03-01

    Recent advances in portable Raman instruments have dramatically increased their application to emergency response and forensics, as well as homeland defense. This paper reviews the relevant attributes and disadvantages of portable Raman spectroscopy, both essentially and instrumentally, to the task of explosives detection in the field. PMID:19023565

  13. Defusing the Cambrian 'explosion'?

    PubMed

    Morris, S C

    1997-02-01

    A recent molecular phylogenetic study argues against the orthodox view that metazoan phyla emerged abruptly during the Cambrian 'explosion', pointing instead to a protracted history for metazoans that arguably stretches back a billion years or more; the fossils, however, seem to tell a different story. PMID:9081666

  14. 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.

  15. Ecotoxicology of Explosives

    SciTech Connect

    Efroymson, Rebecca Ann; Giffen, Neil R; Morrill, Valerie; Jenkins, Thomas

    2009-04-01

    Managing sites contaminated with munitions constituents is an international challenge. Although the choice of approach and the use of Ecological Risk Assessment (ERA) tools may vary from country to country, the assurance of quality and the direction of ecotoxicological research are universally recognized as shared concerns. Drawing on a multidisciplinary team of contributors, 'Ecotoxicology of Explosives' provides comprehensive and critical reviews available to date on fate, transport, and effects of explosives. The book delineates the state of the science of the ecotoxicology of explosives, past, present, and recently developed. It reviews the accessible fate and ecotoxicological data for energetic materials (EMs) and the methods for their development. The chapters characterize the fate of explosives in the environment, then provide information on their ecological effects in key environmental media, including aquatic, sedimentary, and terrestrial habitats. The book also discusses approaches for assembling these lines of evidence for risk assessment purposes. The chapter authors have critically examined the peer-reviewed literature to identify and prioritize the knowledge gaps and to recommend future areas of research. The editors include a review of the genotoxic effects of the EMs and the cellular and molecular mechanisms underlying the toxicity of these chemicals. They also discuss the transport, transformation, and degradation pathways of these chemicals in the environment that underlie the potential hazardous impact and bioaccumulation of EMs in different terrestrial and aquatic ecological receptors. This information translates into practical applications for the environmental risk assessment of EM-contaminated sites and into recommendations for the sustainable use of defense installations.

  16. Steam explosions and associated hazards

    NASA Astrophysics Data System (ADS)

    Theofanus, T. G.

    The different kinds of situation where steam explosions can occur (underwater volcanoes, metals and paper industry, liquefied gas, nuclear reactors) and well-known accidents involving steam explosions are discussed. A set of mechanistic elementary processes, useful for comprehending the key aspects of the steam explosion phenomenon and associated structural damage is outlined. A major steam explosion event in a nuclear reactor that is being subjected to a core-melt accident is assessed to illustrate the methodology, including quantification of uncertainties.

  17. Features of misoriented structures in a copper-copper bilayer plate obtained by explosive welding

    NASA Astrophysics Data System (ADS)

    Rybin, V. V.; Ushanova, E. A.; Zolotorevskii, N. Yu.

    2013-09-01

    Structures induced by deformation in the narrow zone of a contact between two copper plates that is prepared by explosive welding are systematically investigated at the micro-, meso-, and macrolevels. Plastic jets, regions of metal plastic flow anomalous localization, are discovered in areas adjacent to the contact surface. The defect structure of the plastic jets is examined by transmission electron microscopy and electron backscatter diffraction. It is shown that at the mesolevel the plastic jets are regions with a heavily fragmented structure. The statistics of the fragment distribution over misorientations and transverse sizes is studied.

  18. Hydrogen explosion testing with a simulated transuranic drum

    SciTech Connect

    Dykes, K.L.; Meyer, M.L.

    1990-01-01

    Transuranic (TRU) waste generated at the Savannah River Site (SRS) is currently stored onsite for future retrieval and permanent disposal at the Waste Isolation Pilot Plant (WIPP). Some of the TRU waste is stored in vented 210-liter (55-gallon) drums and consists of gloves, wipes, plastic valves, tools, etc. Gas generation caused by radiolysis and biodegradation of these organic waste materials may produce a flammable hydrogen-air mixture (>4% v/v) in the multi-layer plastic waste bags. Using a worst case scenario, a drum explosion test program was carried out to determine the hydrogen concentration necessary to cause removal of the drum lid. Test results indicate an explosive mixture up to 15% v/v of hydrogen can be contained in an SRS TRU drum without total integrity failure via lid removal.

  19. Hydrogen explosion testing with a simulated transuranic drum

    SciTech Connect

    Dykes, K.L.; Meyer, M.L.

    1990-12-31

    Transuranic (TRU) waste generated at the Savannah River Site (SRS) is currently stored onsite for future retrieval and permanent disposal at the Waste Isolation Pilot Plant (WIPP). Some of the TRU waste is stored in vented 210-liter (55-gallon) drums and consists of gloves, wipes, plastic valves, tools, etc. Gas generation caused by radiolysis and biodegradation of these organic waste materials may produce a flammable hydrogen-air mixture (>4% v/v) in the multi-layer plastic waste bags. Using a worst case scenario, a drum explosion test program was carried out to determine the hydrogen concentration necessary to cause removal of the drum lid. Test results indicate an explosive mixture up to 15% v/v of hydrogen can be contained in an SRS TRU drum without total integrity failure via lid removal.

  20. 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.

  1. 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.

  2. New explosive seam welding concepts

    NASA Technical Reports Server (NTRS)

    Bement, L. J.

    1973-01-01

    Recently developed techniques provide totally-confined linear explosive seam welding and produce scarf joint with linear explosive seam welding. Linear ribbon explosives are utilized in making narrow, continuous, airtight joints in variety of aluminum alloys, titanium, copper, brass, and stainless steel.

  3. 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.

  4. Underwater explosive welding of thin tungsten foils and copper

    NASA Astrophysics Data System (ADS)

    Manikandan, P.; Lee, J. O.; Mizumachi, K.; Mori, A.; Raghukandan, K.; Hokamoto, K.

    2011-11-01

    This study demonstrates the ability to clad pure tungsten foils on copper plate using underwater shock waves generated by the detonation of explosive. Microstructural characterization revealed that a higher preset inclination results in wavy morphology. Weld formed at lower inclination exhibit a planar interfacial layer comprising fine grained particles of both components. The plastic flow of tungsten is ascribed to the synergistic influence of high pressure and high strain rate at the collision point.

  5. Fracture of explosively compacted aluminum particles in a cylinder

    NASA Astrophysics Data System (ADS)

    Frost, David; Loiseau, Jason; Goroshin, Sam; Zhang, Fan; Milne, Alec; Longbottom, Aaron

    2015-06-01

    The explosive compaction, fracture and dispersal of aluminum particles contained within a cylinder have been investigated experimentally and computationally. The aluminum particles were weakly confined in a cardboard tube and surrounded a central cylindrical burster charge. The compaction and fracture of the particles are visualized with flash radiography and the subsequent fragment dispersal with high-speed photography. The aluminum fragments produced are much larger than the original aluminum particles and similar in shape to those generated from the explosive fracture of a solid aluminum cylinder, suggesting that the shock transmitted into the aluminum compacts the powder to near solid density. The casing of the burster explosive (plastic-, copper-, and un-cased charges were used) had little influence on the fragment size. The effect of an air gap between the burster and the aluminum particles was also investigated. The particle motion inferred from the radiographs is compared with the predictions of a multimaterial hydrocode.

  6. NQR: From imaging to explosives and drugs detection

    NASA Astrophysics Data System (ADS)

    Osán, Tristán M.; Cerioni, Lucas M. C.; Forguez, José; Ollé, Juan M.; Pusiol, Daniel J.

    2007-02-01

    The main aim of this work is to present an overview of the nuclear quadrupole resonance (NQR) spectroscopy capabilities for solid state imaging and detection of illegal substances, such as explosives and drugs. We briefly discuss the evolution of different NQR imaging techniques, in particular those involving spatial encoding which permit conservation of spectroscopic information. It has been shown that plastic explosives and other forbidden substances cannot be easily detected by means of conventional inspection techniques, such as those based on conventional X-ray technology. For this kind of applications, the experimental results show that the information inferred from NQR spectroscopy provides excellent means to perform volumetric and surface detection of dangerous explosive and drug compounds.

  7. Effects of water states on steam explosion of lignocellulosic biomass.

    PubMed

    Sui, Wenjie; Chen, Hongzhang

    2016-01-01

    The work aimed to identify the complexity and roles of water states in steam explosion process of corn stalk to enhance the treatment efficiency. Results showed that two main water states with different mobility existed in corn stalk and influenced steam explosion treatment. By correlating dynamic water states data to feedstock mechanical properties and treatment process characteristics, the bound water being the excellent plasticizer that reduced the mechanical strength of fibers by over 30%, was conducive to treatment; while, the free water presenting buffering effects in treatment by hindering heat transfer which was reflected by the increase of temperature rising time by 1.29 folds and steam consumption by 2.18 folds, was not conducive. The distinguished point of these two waters was fiber saturated point. By considering treatment efficacy and energy consumption, the significance of fiber saturated point was highlighted as the optimal water states for steam explosion of corn stalk. PMID:26364827

  8. 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

  9. Assessment and mitigation of combustible dust hazards in the plastics industry

    NASA Astrophysics Data System (ADS)

    Stern, Michael C.; Ibarreta, Alfonso; Myers, Timothy J.

    2015-05-01

    A number of recent industrial combustible dust fires and explosions, some involving powders used in the plastics industry, have led to heightened awareness of combustible dust hazards, increased regulatory enforcement, and changes to the current standards and regulations. This paper provides a summary of the fundamentals of combustible dust explosion hazards, comparing and contrasting combustible dust to flammable gases and vapors. The types of tests used to quantify and evaluate the potential hazard posed by plastic dusts are explored. Recent changes in NFPA 654, a standard applicable to combustible dust in the plastics industry, are also discussed. Finally, guidance on the primary methods for prevention and mitigation of combustible dust hazards are provided.

  10. Molecular hydrodynamics of high explosives

    SciTech Connect

    Belak, J.

    1994-11-01

    High explosives release mechanical energy through chemical reactions. Applications of high explosives are vast in the mining and military industries and are beginning to see more civilian applications such as the deployment of airbags in modern automobiles. One of the central issues surrounding explosive materials is decreasing their sensitivity, necessary for their safe handling, while maintaining a high yield. Many practical tests have been devised to determine the sensitivity of explosive materials to shock, to impact, to spark, and to friction. These tests have great value in determining yield and setting precautions for safe handling but tell little of the mechanisms of initiation. How is the mechanical energy of impact or friction transformed into the chemical excitation that initiates explosion? The answer is intimately related to the structure of the explosive material, the size and distribution of grains, the size and presence of open areas such as voids and gas bubbles, and inevitably the bonding between explosive molecules.

  11. Explosive bulk charge

    DOEpatents

    Miller, Jacob Lee

    2015-04-21

    An explosive bulk charge, including: a first contact surface configured to be selectively disposed substantially adjacent to a structure or material; a second end surface configured to selectively receive a detonator; and a curvilinear side surface joining the first contact surface and the second end surface. The first contact surface, the second end surface, and the curvilinear side surface form a bi-truncated hemispherical structure. The first contact surface, the second end surface, and the curvilinear side surface are formed from an explosive material. Optionally, the first contact surface and the second end surface each have a substantially circular shape. Optionally, the first contact surface and the second end surface consist of planar structures that are aligned substantially parallel or slightly tilted with respect to one another. The curvilinear side surface has one of a smooth curved geometry, an elliptical geometry, and a parabolic geometry.

  12. Simulating Explosive Volcanic Eruptions

    NASA Astrophysics Data System (ADS)

    Gisler, G. R.

    2010-12-01

    Explosive volcanic eruptions represent a significant geological hazard. Depending on the setting and the circumstances of the eruption, the hazard may consist of pyroclastic flows, ash falls from plumes, lahars, or floods from sudden melting of glaciers. Numerical modelling of volcanic eruptions is an art still in infancy, but notable strides have been made in the last few years. We list four distinct recent approaches. Pelanti and Leveque (2006) used a finite-volume code to simulate the hot dusty gas of an explosive volcanic jet by coupling the compressible fluid equations of a gas to equations for the pressure-less flow of dust. Dartevelle and Valentine (2007) modelled an explosive eruption that occurred through a geothermal borehole as an analogue of natural volcanic eruptions, using a multiphase gas-particle code. Ogden, Glatzmeier and Wohletz (2008) used a single-fluid Eulerian code to model unsteady flow in an overpressured column. These four different numerical approaches have different realms of applicability and respective advantages and disadvantages. We will discuss some of these, and will also present some all-new simulations with the adaptive-mesh multi-material finite-volume code Sage. We have simulated an erupting column of magma arising from depth, penetrating layered media, and emerging at the surface. When pockets of water are encountered at depth and heated suddenly, the resulting supercritical fluid aids the vertical penetration, eventually exploding violently at the surface. When a dry magma column encounters water or ice at the surface, explosive fragmentation is also observed.

  13. [Explosive "Roman find"].

    PubMed

    Stiel, Michael; Dettmeyer, Reinhard; Madea, Burkhard

    2006-01-01

    A case of a 40-year-old hobby archeologist is presented who searched for remains from Roman times. After finding an oblong, cylindrical object, he opened it with a saw to examine it, which triggered an explosion killing the man. The technical investigation of the remains showed that the find was actually a grenade from the 2nd World War. The autopsy findings and the results of the criminological investigation are presented. PMID:16529179

  14. 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.

  15. 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.

  16. Adhesion of explosives.

    PubMed

    Chaffee-Cipich, Michelle N; Sturtevant, Bryce D; Beaudoin, Stephen P

    2013-06-01

    It is of increasing importance to understand how explosive particles adhere to surfaces in order to understand how to remove them for detection in airport or other security settings. In this study, adhesion forces between royal demolition explosive (cyclotrimethylenetrinitramine) (RDX), pentaerythritol tetranitrate (PETN), and trinitrotoluene (TNT) in their crystalline forms and aluminum coupons with three finishes, acrylic melamine (clear coating), polyester acrylic melamine (white coating) automotive finishes, and a green military-grade finish, were measured and modeled. The force measurements were performed using the atomic force microscopy (AFM)-based colloidal probe microscopy (CPM) method. Explosive particles were mounted on AFM cantilevers and repeatedly brought in and out of contact with the surfaces of interest while the required force needed to pull out of contact was recorded. An existing Matlab-based simulator was used to describe the observed adhesion force distributions, with excellent agreement. In these simulations, the measured topographies of the interacting surfaces were considered, although the geometries were approximated. The simulations were performed using a van der Waals force-based adhesion model and a composite effective Hamaker constant. It was determined that certain combinations of roughness on the interacting surfaces led to preferred particle-substrate orientations that produced extreme adhesion forces. PMID:23510004

  17. Superenantioselective chiral surface explosions.

    PubMed

    Gellman, Andrew J; Huang, Ye; Feng, Xu; Pushkarev, Vladimir V; Holsclaw, Brian; Mhatre, Bharat S

    2013-12-26

    Chiral inorganic materials predated life on Earth, and their enantiospecific surface chemistry may have played a role in the origins of biomolecular homochirality. However, enantiospecific differences in the interaction energies of chiral molecules with chiral surfaces are small and typically lead to modest enantioselectivities in adsorption, catalysis, and chemistry on chiral surfaces. To yield high enantioselectivities, small energy differences must be amplified by reaction mechanisms such as autocatalytic surface explosions which have nonlinear kinetics. Herein, we report the first observations of superenantiospecificity resulting from an autocatalytic surface explosion reaction of a chiral molecule on a naturally chiral surface. R,R- and S,S-tartaric acid decompose via a vacancy-mediated surface explosion mechanism on Cu single crystal surfaces. When coupled with surface chirality, this leads to decomposition rates that exhibit extraordinarily high enantiospecificity. On the enantiomorphs of naturally chiral Cu(643)(R&S), Cu(17,5,1)(R&S), Cu(531)(R&S) and Cu(651)(R&S) single crystal surfaces, R,R- and S,S-tartaric acid exhibit enantiospecific decomposition rates that differ by as much as 2 orders of magnitude, despite the fact that the effective rates constants for decomposition differ by less than a factor of 2. PMID:24261645

  18. The use of MAVIS II to integrate the modeling and analysis of explosive valve interactions

    SciTech Connect

    Ng, R.; Kwon, D.M.

    1998-12-31

    The MAVIS II computer program provides for the modeling and analysis of explosive valve interactions. This report describes the individual components of the program and how MAVIS II is used with other available tools to integrate the design and understanding of explosive valves. The rationale and model used for each valve interaction is described. Comparisons of the calculated results with available data have demonstrated the feasibility and accuracy of using MAVIS II for analytical studies of explosive valve interactions. The model used for the explosive or pyrotechnic used as the driving force in explosive valves is the most critical to be understood and modeled. MAVIS II is an advanced version that incorporates a plastic, as well as elastic, modeling of the deformations experienced when plungers are forced into a bore. The inclusion of a plastic model has greatly expanded the use of MAVIS for all categories (opening, closure, or combined) of valves, especially for the closure valves in which the sealing operation requires the plastic deformation of either a plunger or bore over a relatively large area. In order to increase its effectiveness, the use of MAVIS II should be integrated with the results from available experimental hardware. Test hardware such as the Velocity Interferometer System for Any Reflector (VISAR) and Velocity Generator test provide experimental data for accurate comparison of the actual valve functions. Variable Explosive Chamber (VEC) and Constant Explosive Volume (CEV) tests are used to provide the proper explosive equation-of-state for the MAVIS calculations of the explosive driving forces. The rationale and logistics of this integration is demonstrated through an example. A recent valve design is used to demonstrate how MAVIS II can be integrated with experimental tools to provide an understanding of the interactions in this valve.

  19. Hidden explosives detector employing pulsed neutron and x-ray interrogation

    DOEpatents

    Schultz, F.J.; Caldwell, J.T.

    1993-04-06

    Methods and systems for the detection of small amounts of modern, highly-explosive nitrogen-based explosives, such as plastic explosives, hidden in airline baggage. Several techniques are employed either individually or combined in a hybrid system. One technique employed in combination is X-ray imaging. Another technique is interrogation with a pulsed neutron source in a two-phase mode of operation to image both nitrogen and oxygen densities. Another technique employed in combination is neutron interrogation to form a hydrogen density image or three-dimensional map. In addition, deliberately-placed neutron-absorbing materials can be detected.

  20. Hidden explosives detector employing pulsed neutron and x-ray interrogation

    DOEpatents

    Schultz, Frederick J.; Caldwell, John T.

    1993-01-01

    Methods and systems for the detection of small amounts of modern, highly-explosive nitrogen-based explosives, such as plastic explosives, hidden in airline baggage. Several techniques are employed either individually or combined in a hybrid system. One technique employed in combination is X-ray imaging. Another technique is interrogation with a pulsed neutron source in a two-phase mode of operation to image both nitrogen and oxygen densities. Another technique employed in combination is neutron interrogation to form a hydrogen density image or three-dimensional map. In addition, deliberately-placed neutron-absorbing materials can be detected.

  1. 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.

  2. Simulation of Seismic Waves for Nuclear Explosion Monitoring

    NASA Astrophysics Data System (ADS)

    Rodgers, Arthur

    2010-05-01

    Improvements in numerical algorithms for simulating shock wave and anelastic wave excitation and propagation in three-dimensional (3D) earth models and the inexorable increase in computational power now make it possible to simulate the ground motions generated by underground nuclear explosions with fidelities commensurate with the frequency content of observations. Though it is not possible to model the end-to-end generation and propagation of the complete waveform to the sensor at teleseismic distances and high-frequencies, it is possible to simulate different regimes and gain valuable phenomenological insights to reduce uncertainties in nuclear monitoring observables such as yield scaling, explosion source models and S-wave generation of underground explosions. Currently we are modeling three regimes: 1) the immediate near source hydrodynamic region (~3 km) including the impact of source emplacement conditions (e.g. material strength and depth-of-burial), shock wave excitation and non-linear effect (cavity formation, porous compaction, damage, plasticity); 2) the local near-source region (~40 km) including 3D structure (free-surface topography and volumetric heterogeneity) using a Cartesian finite difference method; and 3) regional-scale (~2000 km) anelastic propagation in 3D structure using a spherical spectral element method. We will present simulations of recent underground explosions conducted in North Korea to illustrate the application simulations to nuclear explosion monitoring.

  3. Non-shock initiation model for explosive families : experimental results.

    SciTech Connect

    Anderson, Mark U.; Jensen, Charles B.; Todd, Steven N.; Hugh, Chance G.; Caipen, Terry L.

    2010-03-01

    The 'DaMaGe-Initiated-Reaction' (DMGIR) computational model has been developed to predict the response of high explosives to non-shock mechanical insults. The distinguishing feature of this model is the introduction of a damage variable, which relates the evolution of damage to the initiation of a reaction in the explosive, and its growth to detonation. Specifically designed experiments were used to study the initiation process of each explosive family with embedded shock sensors and optical diagnostics. The experimental portion of this model development began with a study of PBXN-5 to develop DMGIR model coefficients for the rigid plastic bonded family, followed by studies of the cast, and bulk-moldable explosive families. The experimental results show an initiation mechanism that is related to input energy and material damage, with well defined initiation thresholds for each explosive family. These initiation details will extend the predictive capability of the DMGIR model from the rigid family into the cast and bulk-moldable families.

  4. 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.

  5. Ear Plastic Surgery

    MedlinePlus

    ... Find an ENT Doctor Near You Ear Plastic Surgery Ear Plastic Surgery Patient Health Information News media ... weight earrings. Does Insurance Pay for Cosmetic Ear Surgery? Insurance usually does not cover surgery solely for ...

  6. Prompt Reaction of Aluminum in Detonating Explosives

    SciTech Connect

    Sandusky, H. W.; Granholm, R. H.

    2006-07-28

    The potential of aluminum (Al) reaction to boost detonation energy has been studied for decades, most recently spurred by the availability of nanometer-sized particles. A literature review is consistent with results from the small-scale shock reactivity test (SSRT). In this test, <1/2-g samples in confinement are shock loaded on one end, and the output at the other end dents a soft witness block. For samples in which 0.3 g of cyclotetramethylenetetranitramine (HMX) was mixed with 8 {mu}m Al, the deepest dent occurred at 15% Al. When ammonium perchlorate (AP) was mixed with the same Al, the increased dents were consistent with changes in detonation velocity previously reported on similar mixtures. One outcome of this study is a new interpretation for the participation of Al in large scale gap tests on plastic-bonded explosives, which was discussed by Bernecker at this meeting in 1987.

  7. Plastics in Building.

    ERIC Educational Resources Information Center

    Skeist, Irving, Ed.

    The evaluation and use of plastics in the construction industry are explained. The contributors offer extensive, timely, and thoroughly researched data on the chemistry, properties, functions, engineering behavior, and specific applications of plastics to building requirements. The major subjects discussed in depth are--(1) the role of plastics in

  8. Tomorrow's Plastic World

    ERIC Educational Resources Information Center

    Macdonald, Averil

    2005-01-01

    Far from being just cheap packaging materials, plastics may be the materials of tomorrow. Plastic can conduct electricity, and this opens up a host of high-tech possibilities in the home and in energy generation. These possibilities are discussed here along with how plastic can be recycled and perhaps even grown.

  9. Processing of plastics

    PubMed Central

    Spaak, Albert

    1975-01-01

    An overview is given of the processing of plastic materials from the handling of polymers in the pellet and powder form to manufacturing of a plastic fabricated product. Various types of equipment used and melt processing ranges of various polymer formulations to make the myriad of plastic products that are commercially available are discussed. PMID:1175556

  10. Plastics in Building.

    ERIC Educational Resources Information Center

    Skeist, Irving, Ed.

    The evaluation and use of plastics in the construction industry are explained. The contributors offer extensive, timely, and thoroughly researched data on the chemistry, properties, functions, engineering behavior, and specific applications of plastics to building requirements. The major subjects discussed in depth are--(1) the role of plastics in…

  11. Gasdynamics of explosions today.

    NASA Technical Reports Server (NTRS)

    Brode, H. L.; Glass, I. I.; Oppenheim, A. K.

    1971-01-01

    A brief review is given of blast and detonation wave phenomena and some of their uses in war and peace. It is concluded that great strides have been made over the last three decades toward the physical understanding, the analytical-numerical solution, and the measurement of dynamic and thermodynamic quantities, also taking into consideration severe environments and extremely short durations. Questions of internal ballistics are discussed together with hypervelocity launchers and shock tubes, collapsing cylindrical drivers, spherical implosions, explosive weapons, dynamic response, and equation of state data.

  12. Explosions on the Sun

    NASA Astrophysics Data System (ADS)

    Harra, Louise K.

    2005-10-01

    I describe two of the most dynamic and highly energetic phenomena in the Solar System - these are the eruptions and flaring that occur on the Sun. They can release as much energy as 10 million volcanoes, and throw out material into the solar system with similar mass to Mount Everest! The theories of what can produce such an explosion are based around the magnetic field that confines the gas. These events can produce emission right across the electromagnetic spectrum. The status of our ability to predict these events is discussed.

  13. Simplified explosive-weld evaluation

    NASA Technical Reports Server (NTRS)

    Mclarty, D. M.

    1976-01-01

    Weld surfaces, coated with commercially available molybdenum disulfide, allow visual inspection of significant indications of bond quality. Process reduces number of trial welds, making explosive bonding more competitive.

  14. Towards optoelectronic detection of explosives

    NASA Astrophysics Data System (ADS)

    Wojtas, J.; Stacewicz, T.; Bielecki, Z.; Rutecka, B.; Medrzycki, R.; Mikolajczyk, J.

    2013-06-01

    Detection of explosives is an important challenge for contemporary science and technology of security systems. We present an application of NOx sensors equipped with concentrator in searching of explosives. The sensors using CRDS with blue — violet diode lasers (410 nm) as well as with QCL lasers (5.26 μm and 4.53 μm) are described. The detection method is based either on reaction of the sensors to the nitrogen oxides emitted by explosives or to NOx produced during thermal decomposition of explosive vapours. For TNT, PETN, RDX, and HMX the detection limit better than 1 ng has been achieved.

  15. Explosive scabbling of structural materials

    DOEpatents

    Bickes, Jr., Robert W.; Bonzon, Lloyd L.

    2002-01-01

    A new approach to scabbling of surfaces of structural materials is disclosed. A layer of mildly energetic explosive composition is applied to the surface to be scabbled. The explosive composition is then detonated, rubbleizing the surface. Explosive compositions used must sustain a detonation front along the surface to which it is applied and conform closely to the surface being scabbled. Suitable explosive compositions exist which are stable under handling, easy to apply, easy to transport, have limited toxicity, and can be reliably detonated using conventional techniques.

  16. Zirconium hydride containing explosive composition

    DOEpatents

    Walker, Franklin E.; Wasley, Richard J.

    1981-01-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a donor additive comprising a non-explosive compound or mixture of non-explosive compounds which when subjected to an energy fluence of 1000 calories/cm.sup.2 or less is capable of releasing free radicals each having a molecular weight between 1 and 120. Exemplary donor additives are dibasic acids, polyamines and metal hydrides.

  17. Low voltage nonprimary explosive detonator

    DOEpatents

    Dinegar, Robert H.; Kirkham, John

    1982-01-01

    A low voltage, electrically actuated, nonprimary explosive detonator is disclosed wherein said detonation is achieved by means of an explosive train in which a deflagration-to-detonation transition is made to occur. The explosive train is confined within a cylindrical body and positioned adjacent to low voltage ignition means have electrical leads extending outwardly from the cylindrical confining body. Application of a low voltage current to the electrical leads ignites a self-sustained deflagration in a donor portion of the explosive train which then is made to undergo a transition to detonation further down the train.

  18. Controlled by Distant Explosions

    NASA Astrophysics Data System (ADS)

    2007-03-01

    VLT Automatically Takes Detailed Spectra of Gamma-Ray Burst Afterglows Only Minutes After Discovery A time-series of high-resolution spectra in the optical and ultraviolet has twice been obtained just a few minutes after the detection of a gamma-ray bust explosion in a distant galaxy. The international team of astronomers responsible for these observations derived new conclusive evidence about the nature of the surroundings of these powerful explosions linked to the death of massive stars. At 11:08 pm on 17 April 2006, an alarm rang in the Control Room of ESO's Very Large Telescope on Paranal, Chile. Fortunately, it did not announce any catastrophe on the mountain, nor with one of the world's largest telescopes. Instead, it signalled the doom of a massive star, 9.3 billion light-years away, whose final scream of agony - a powerful burst of gamma rays - had been recorded by the Swift satellite only two minutes earlier. The alarm was triggered by the activation of the VLT Rapid Response Mode, a novel system that allows for robotic observations without any human intervention, except for the alignment of the spectrograph slit. ESO PR Photo 17a/07 ESO PR Photo 17a/07 Triggered by an Explosion Starting less than 10 minutes after the Swift detection, a series of spectra of increasing integration times (3, 5, 10, 20, 40 and 80 minutes) were taken with the Ultraviolet and Visual Echelle Spectrograph (UVES), mounted on Kueyen, the second Unit Telescope of the VLT. "With the Rapid Response Mode, the VLT is directly controlled by a distant explosion," said ESO astronomer Paul Vreeswijk, who requested the observations and is lead-author of the paper reporting the results. "All I really had to do, once I was informed of the gamma-ray burst detection, was to phone the staff astronomers at the Paranal Observatory, Stefano Bagnulo and Stan Stefl, to check that everything was fine." The first spectrum of this time series was the quickest ever taken of a gamma-ray burst afterglow, let alone with an instrument such as UVES, which is capable of splitting the afterglow light with uttermost precision. What is more, this amazing record was broken less than two months later by the same team. On 7 June 2006, the Rapid-Response Mode triggered UVES observations of the afterglow of an even more distant gamma-ray source a mere 7.5 minutes after its detection by the Swift satellite. Gamma-ray bursts are the most intense explosions in the Universe. They are also very brief. They randomly occur in galaxies in the distant Universe and, after the energetic gamma-ray emission has ceased, they radiate an afterglow flux at longer wavelengths (i.e. lower energies). They are classified as long and short bursts according to their duration and burst energetics, but hybrid bursts have also been discovered (see ESO PR 49/06). The scientific community agrees that gamma-ray bursts are associated with the formation of black holes, but the exact nature of the bursts remains enigmatic. ESO PR Photo 17b/07 ESO PR Photo 17b/07 Kueyen at Night Because a gamma-ray burst typically occurs at very large distances, its optical afterglow is faint. In addition, it fades very rapidly: in only a few hours the optical afterglow brightness can fade by as much as a factor of 500. This makes detailed spectral analysis possible only for a few hours after the gamma-ray detection, even with large telescopes. During the first minutes and hours after the explosion, there is also the important opportunity to observe time-dependent phenomena related to the influence of the explosion on its surroundings. The technical challenge therefore consists of obtaining high-resolution spectroscopy with 8-10 m class telescopes as quickly as possible. "The afterglow spectra provide a wealth of information about the composition of the interstellar medium of the galaxy in which the star exploded. Some of us even hoped to characterize the gas in the vicinity of the explosion," said team member Cédric Ledoux (ESO). ESO PR Photo 17c/07 ESO PR Photo 17c/07 The Kueyen Control Room The Rapid Response Mode UVES observations of 17 April 2006 allowed the astronomers to discover variable spectral features associated with a huge gas cloud in the host galaxy of the gamma-ray burst. The cloud was found to be neutral but excited by the radiation from the UV afterglow light. From detailed modelling of these observations, the astronomers were able - for the first time - to not only pinpoint the physical mechanism responsible for the excitation of the atoms, but also determine the distance of the cloud to the GRB. This distance was found to be 5,500 light-years, which is much further out than was previously thought. Either this is a special case, or the common picture that the features seen in optical spectra originate very close to the explosion has to be revised. As a comparison, this distance of 5,500 light-years is more than one fifth of that between the Sun and the centre of our Galaxy. "All the material in this region of space must have been ionised, that is, the atoms have been stripped of most if not all of their electrons," said co-author Alain Smette (ESO). "Were there any life in this region of the Universe, it would most probably have been eradicated." "With the Rapid-Response Mode of the VLT, we are really looking at gamma-ray bursts as quickly as possible," said team member Andreas Jaunsen from the University of Oslo (Norway). "This is crucial if we are to unravel the mysteries of these gigantic explosions and their links with black holes!" More Information The two gamma-ray bursts were discovered with the NASA/ASI/PPARC Swift satellite, which is dedicated to the discovery of these powerful cosmic explosions. Preliminary reports on these observations have been presented in GCN GRB Observation Reports 4974 and 5237. A paper is also in press in the journal Astronomy & Astrophysics ("Rapid-Response Mode VLT/UVES spectroscopy of GRB 060418 - Conclusive evidence for UV pumping from the time evolution of Fe II and Ni II excited- and metastable-level populations" by P. M. Vreeswijk et al.). DOI: 10.1051/0004-6361:20066780 The team is composed of Paul Vreeswijk, Cédric Ledoux, Alain Smette, Andreas Kaufer and Palle Møller (ESO), Sara Ellison (University of Victoria, Canada), Andreas Jaunsen (University of Oslo, Norway), Morten Andersen (AIP, Potsdam, Germany), Andrew Fruchter (STScI, Baltimore, USA), Johan Fynbo and Jens Hjorth (Dark Cosmology Centre, Copenhagen, Denmark), Patrick Petitjean (IAP, Paris, France), Sandra Savaglio (MPE, Garching, Germany), and Ralph Wijers (Astronomical Institute, University of Amsterdam, The Netherlands). Paul Vreeswijk was at the time of this study also associated with the Universidad de Chile, Santiago.

  19. Biodegradability of plastics.

    PubMed

    Tokiwa, Yutaka; Calabia, Buenaventurada P; Ugwu, Charles U; Aiba, Seiichi

    2009-09-01

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed. PMID:19865515

  20. Biodegradability of Plastics

    PubMed Central

    Tokiwa, Yutaka; Calabia, Buenaventurada P.; Ugwu, Charles U.; Aiba, Seiichi

    2009-01-01

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed. PMID:19865515

  1. Laser machining of explosives

    DOEpatents

    Perry, Michael D.; Stuart, Brent C.; Banks, Paul S.; Myers, Booth R.; Sefcik, Joseph A.

    2000-01-01

    The invention consists of a method for machining (cutting, drilling, sculpting) of explosives (e.g., TNT, TATB, PETN, RDX, etc.). By using pulses of a duration in the range of 5 femtoseconds to 50 picoseconds, extremely precise and rapid machining can be achieved with essentially no heat or shock affected zone. In this method, material is removed by a nonthermal mechanism. A combination of multiphoton and collisional ionization creates a critical density plasma in a time scale much shorter than electron kinetic energy is transferred to the lattice. The resulting plasma is far from thermal equilibrium. The material is in essence converted from its initial solid-state directly into a fully ionized plasma on a time scale too short for thermal equilibrium to be established with the lattice. As a result, there is negligible heat conduction beyond the region removed resulting in negligible thermal stress or shock to the material beyond a few microns from the laser machined surface. Hydrodynamic expansion of the plasma eliminates the need for any ancillary techniques to remove material and produces extremely high quality machined surfaces. There is no detonation or deflagration of the explosive in the process and the material which is removed is rendered inert.

  2. Explosive components facility certification tests

    SciTech Connect

    Dorrell, L.; Johnson, D.

    1995-08-01

    Sandia National Laboratories has recently completed construction of a new Explosive Components Facility (ECF) that will be used for the research and development of advanced explosives technology. The ECF includes nine indoor firing pads for detonating explosives and monitoring the detonations. Department of Energy requirements for certification of this facility include detonation of explosive levels up to 125 percent of the rated firing pad capacity with no visual structural degradation resulting from the explosion. The Explosives Projects and Diagnostics Department at Sandia decided to expand this certification process to include vibration and acoustic monitoring at various locations throughout the building during these explosive events. This information could then be used to help determine the best locations for noise and vibration sensitive equipment (e.g. scanning electron microscopes) used for analysis throughout the building. This facility has many unique isolation features built into the explosive chamber and laboratory areas of the building that allow normal operation of other building activities during explosive tests. This paper discusses the design of this facility and the various types of explosive testing performed by the Explosives Projects and Diagnostics Department at Sandia. However, the primary focus of the paper is directed at the vibration and acoustic data acquired during the certification process. This includes the vibration test setup and data acquisition parameters, as well as analysis methods used for generating peak acceleration levels and spectral information. Concerns over instrumentation issues such as the choice of transducers (appropriate ranges, resonant frequencies, etc.) and measurements with long cable lengths (500 feet) are also discussed.

  3. New plastic joints for plastic orthoses.

    PubMed

    Watanabe, H; Kutsuna, T; Morinaga, H; Okabe, T

    1982-04-01

    Plastic joints for orthoses have more advantages than metal joints. They are lightweight, noiseless comfortable to use, rust proof, corrosion free, and radiolucent. Two types of plastic joints were developed by the authors, one for the ankle joint and the other for the knee joint, elbow joint or hip joint. Polypropylene was chosen as the joint material because of its appropriate flexibility and toughness. PMID:7079105

  4. Numerical Model for Hydrovolcanic Explosions.

    NASA Astrophysics Data System (ADS)

    Mader, Charles; Gittings, Michael

    2007-03-01

    A hydrovolcanic explosion is generated by the interaction of hot magma with ground water. It is called Surtseyan after the 1963 explosive eruption off Iceland. The water flashes to steam and expands explosively. Liquid water becomes water gas at constant volume and generates pressures of about 3GPa. The Krakatoa hydrovolcanic explosion was modeled using the full Navier-Stokes AMR Eulerian compressible hydrodynamic code called SAGE [1] which includes the high pressure physics of explosions. The water in the hydrovolcanic explosion was described as liquid water heated by magma to 1100 K. The high temperature water is treated as an explosive with the hot liquid water going to water gas. The BKW [2] steady state detonation state has a peak pressure of 8.9 GPa, a propagation velocity of 5900 meters/sec and the water is compressed to 1.33 g/cc. [1] Numerical Modeling of Water Waves, Second Edition, Charles L. Mader, CRC Press 2004. [2] Numerical Modeling of Explosions and Propellants, Charles L. Mader, CRC Press 1998.

  5. Variations on the "Whoosh" Bottle Alcohol Explosion Demonstration Including Safety Notes

    NASA Astrophysics Data System (ADS)

    Fortman, John J.; Rush, Andrea C.; Stamper, Jennifer E.

    1999-08-01

    The explosion or burning of methanol, ethanol, n-propanol, and isopropanol in large small-necked bottles when ignited with a match has been studied with respect to the nature of the alcohol, temperature, concentration dilutions with water, oxygen concentration, plastic versus glass bottles, and salts added for color. The various effects are explained in terms of vapor pressures. Safety guidelines are emphasized.

  6. Pulsed terahertz spectroscopy and imaging applied to inspection of explosives and inflammable liquids

    NASA Astrophysics Data System (ADS)

    Yamamoto, Kohji; Yamaguchi, Mariko; Miyamaru, Fumiaki; Tani, Masahiko; Hangyo, Masanori; Ikeda, Takeshi; Matsushita, Akira; Koide, Kenji; Tatsuno, Michiaki; Manami, Yukio

    We carried out applied researches on the pulsed terahertz spectroscopy and the terahertz imaging to detect the C-4 explosive hidden in a mail and inflammable liquids stored in plastic bottles. We confirm that THz techniques are quite efficient at contactless and nondestructive inspection of hazardous materials used in terrorist activities.

  7. The Scaled Thermal Explosion Experiment

    SciTech Connect

    Wardell, J F; Maienschein, J L

    2002-07-05

    We have developed the Scaled Thermal Explosion Experiment (STEX) to provide a database of reaction violence from thermal explosion for explosives of interest. Such data are needed to develop, calibrate, and validate predictive capability for thermal explosions using simulation computer codes. A cylinder of explosive 25, 50 or 100 mm in diameter, is confined in a steel cylinder with heavy end caps, and heated under controlled conditions until reaction. Reaction violence is quantified through non-contact micropower impulse radar measurements of the cylinder wall velocity and by strain gauge data at reaction onset. Here we describe the test concept, design and diagnostic recording, and report results with HMX- and RDX-based energetic materials.

  8. 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.

  9. High performance, extrusion cast explosive

    SciTech Connect

    Scribner, K.J.

    1984-02-01

    The Lawrence Livermore National Laboratory has been developing a new high energy explosive system for use in precision, high performance munitions. It is a system because the composition and the manufacturing techniques are both unique. The explosive has an energy/density greater than 78% Octol. It is similar to modern type cast/cure explosives except that we can work with higher apparent viscosities since we use low pressure hydraulic systems for deaeration and casting of the explosive. We load any desired device configuration. The crystalline HMX has a nominal 60 ..mu.. particle size which contributes to an extremely smooth detonation front. This explosive is suitable for use in the most critical applications such as shaped charges and self forging fragment systems.

  10. Shock and High Strain Rate Characterization of HTPB with Varying Plasticizer

    NASA Astrophysics Data System (ADS)

    Montaigne, Didier; Neel, Christopher; Gould, Peter; Molek, Christopher; Jordan, Jennifer

    2013-06-01

    Hydroxy-terminated polybutadiene (HTPB) has long been used as a binder in propellants and explosives. However, cured HTPB rubbery polyurethanes have not been characterized in a systematic fashion as function of plasticizer content. In this study, four isocyanate-cured HTPB variants with different amounts of plasticizer have been formulated. The materials were characterized using dynamic mechanical analysis and quasi-static and dynamic compression experiments. Additionally, the shock Hugoniot was measured on the two extremes of the material - no plasticizer and maximum plasticizer. The properties of the HTPB were predicted using the Porter-Gould model for polymers.

  11. How Plastics Work

    NASA Astrophysics Data System (ADS)

    Bloomfield, Louis

    2013-03-01

    We encounter plastics every day, but despite their widespread use, amazing range of properties, and basic scientific underpinnings, most physicists--like most people--know relatively little about plastics. In contrast to hard crystalline and amorphous solids (e.g., metals, salts, ceramics, and glasses), we take plastics for granted, select them carelessly, and examine them more closely only on a need-to-know basis. By ignoring plastics until we need them, however, we risk not knowing what we don't know and using the wrong ones. To repurpose a familiar advertisement, ``there's a plastic for that.'' This talk will review some of the basic physics and science of plastics. It will examine the roles of temperature, order, intermolecular forces, entanglements, and linkages in plastics, and how those issues affect the properties of a given plastic. We'll stop along the way to recognize a few of the more familiar plastics, natural and synthetic, and explain some of their mechanical, chemical, and optical properties. The talk will conclude by explaining the remarkable properties of a plastic that has been largely misunderstood since its discovery 70 years ago: Silly Putty.

  12. Mixing in explosions

    SciTech Connect

    Kuhl, A.L.

    1993-12-01

    Explosions always contain embedded turbulent mixing regions, for example: boundary layers, shear layers, wall jets, and unstable interfaces. Described here is one particular example of the latter, namely, the turbulent mixing occurring in the fireball of an HE-driven blast wave. The evolution of the turbulent mixing was studied via two-dimensional numerical simulations of the convective mixing processes on an adaptive mesh. Vorticity was generated on the fireball interface by baroclinic effects. The interface was unstable, and rapidly evolved into a turbulent mixing layer. Four phases of mixing were observed: (1) a strong blast wave phase; (2) and implosion phase; (3) a reshocking phase; and (4) an asymptotic mixing phase. The flowfield was azimuthally averaged to evaluate the mean and r.m.s. fluctuation profiles across the mixing layer. The vorticity decayed due to a cascade process. This caused the corresponding enstrophy parameter to increase linearly with time -- in agreement with homogeneous turbulence calculations of G.K. Batchelor.

  13. Assessing nuclear explosions

    NASA Astrophysics Data System (ADS)

    Smith, Joseph V.

    The all-Union session on the Geophysical and Geochemical Consequences of Nuclear Explosions at the 1983 AGU Fall Meeting attracted a large audience, and many were unable to find a seat or standing room. The speakers and questioners emphasized the complexity of the processes and the need to extend the computer models. In particular, the global-circulation models presented byscientists from the National Center for Atmospheric Research showed that smoke/dust clouds should cause major changes in the weather systems with great contrast between the temperature perturbations over oceanic, coastal, and continental regions. Important developments in the models and conclusions can be expected over the next few years as AGU members from many disciplines contribute their skills.

  14. Nucleosynthesis in stellar explosions

    SciTech Connect

    Woosley, S.E.; Axelrod, T.S.; Weaver, T.A.

    1983-01-01

    The final evolution and explosion of stars from 10 M/sub solar/ to 10/sup 6/ M/sub solar/ are reviewed with emphasis on factors affecting the expected nucleosynthesis. We order our paper in a sequence of decreasing mass. If, as many suspect, the stellar birth function was peaked towards larger masses at earlier times (see e.g., Silk 1977; but also see Palla, Salpeter, and Stahler 1983), this sequence of masses might also be regarded as a temporal sequence. At each stage of Galactic chemical evolution stars form from the ashes of preceding generations which typically had greater mass. A wide variety of Type I supernova models, most based upon accreting white dwarf stars, are also explored using the expected light curves, spectra, and nucleosynthesis as diagnostics. No clearly favored Type I model emerges that is capable of simultaneously satisfying all three constraints.

  15. 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.

  16. On the violence of thermal explosion in solid explosives

    SciTech Connect

    Chidester, S.K.; Tarver, C.M.; Green, L.G.; Urtiew, P.A.

    1997-07-01

    Heavily confined cylinders of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and triaminotrinitrobenzene (TATB) were heated at rates varying from 2 C/min to 3.3 C/h. Fourteen of the cylinders were hollow, and inner metallic liners with small heaters attached were used to produce uniform temperatures just prior to explosion. A complex thermocouple pattern was used to measure the temperature history throughout the charge and to determine the approximate location where the runaway exothermic reaction first occurred. The violence of the resulting explosion was measured using velocity pin arrays placed inside and outside of the metal confinement cylinders, flash x-rays, overpressure gauges, and fragment collection techniques. Five cylinders were intentionally detonated for violence comparisons. The measured temperature histories, times to explosion, and the locations of first reaction agreed closely with those calculated by a two-dimensional heat transfer code using multistep chemical decomposition models. The acceleration of the confining metal cylinders by the explosion process was accurately simulated using a two-dimensional pressure dependent deflagration reactive flow hydrodynamic mode. The most violent HMX thermal explosions gradually accelerated their outer cases to velocities approaching those of intentional detonations approximately 120 {micro}m after the onset of explosion. The measured inner cylinder collapse velocities from thermal explosions were considerably lower than those produced by detonations. In contrast to the HMX thermal reactions, no violent thermal explosions were produced by the TATB-based explosive LX-17. A heavily confined, slowly heated LX-17 test produced sufficient pressure to cause a 0.1 cm bend in a 2 cm thick steel plate.

  17. Our plastic age.

    PubMed

    Thompson, Richard C; Swan, Shanna H; Moore, Charles J; vom Saal, Frederick S

    2009-07-27

    Within the last few decades, plastics have revolutionized our daily lives. Globally we use in excess of 260 million tonnes of plastic per annum, accounting for approximately 8 per cent of world oil production. In this Theme Issue of Philosophical Transactions of the Royal Society, we describe current and future trends in usage, together with the many benefits that plastics bring to society. At the same time, we examine the environmental consequences resulting from the accumulation of waste plastic, the effects of plastic debris on wildlife and concerns for human health that arise from the production, usage and disposal of plastics. Finally, we consider some possible solutions to these problems together with the research and policy priorities necessary for their implementation. PMID:19528049

  18. Our plastic age

    PubMed Central

    Thompson, Richard C.; Swan, Shanna H.; Moore, Charles J.; vom Saal, Frederick S.

    2009-01-01

    Within the last few decades, plastics have revolutionized our daily lives. Globally we use in excess of 260 million tonnes of plastic per annum, accounting for approximately 8 per cent of world oil production. In this Theme Issue of Philosophical Transactions of the Royal Society, we describe current and future trends in usage, together with the many benefits that plastics bring to society. At the same time, we examine the environmental consequences resulting from the accumulation of waste plastic, the effects of plastic debris on wildlife and concerns for human health that arise from the production, usage and disposal of plastics. Finally, we consider some possible solutions to these problems together with the research and policy priorities necessary for their implementation. PMID:19528049

  19. 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.

  20. Plasticized phenolphthalein polycarbonate

    NASA Technical Reports Server (NTRS)

    Harrison, E. S.

    1976-01-01

    Phenolphthalein polycarbonate was successfully plasticized with polychlorinated biphenyls (e.g., Aroclor 1231) or tricresyl phosphate and cast from tetrahydrofuran to give clear films without loss of fire resistance. At loadings of 20 to 30 percent plasticizer the Tg was lowered to approximately 100 C which would render phenolphthalein polycarbonate easily moldable. Although these materials had some mechanical integrity as shown by their film forming ability, the room temperature toughness of the plasticized polymer was not significantly improved over unmodified polymer.

  1. Additives in plastics.

    PubMed Central

    Deanin, R D

    1975-01-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products. PMID:1175566

  2. Astrocytes: Orchestrating synaptic plasticity?

    PubMed

    De Pittà, M; Brunel, N; Volterra, A

    2016-05-26

    Synaptic plasticity is the capacity of a preexisting connection between two neurons to change in strength as a function of neural activity. Because synaptic plasticity is the major candidate mechanism for learning and memory, the elucidation of its constituting mechanisms is of crucial importance in many aspects of normal and pathological brain function. In particular, a prominent aspect that remains debated is how the plasticity mechanisms, that encompass a broad spectrum of temporal and spatial scales, come to play together in a concerted fashion. Here we review and discuss evidence that pinpoints to a possible non-neuronal, glial candidate for such orchestration: the regulation of synaptic plasticity by astrocytes. PMID:25862587

  3. Quantitative experiments on phreatomagmatic explosions

    NASA Astrophysics Data System (ADS)

    Zimanowski, Bernd; Frhlich, Georg; Lorenz, Volker

    1991-12-01

    An experimental set-up for controlled generation of thermal explosions (Fuel Coolant Interactions) has been built by an interdisciplinary research group of volcanologists, physicists and engineering scientists: The TEE-Haus (Thermal Explosion Experiment). During the last 3 years more than 500 experimental runs were performed. Aim of the project was not to build a "mini volcano" but to produce igniteable mixtures of water and hot melt on a small scale in order to investigate basic physical aspects. Such small scale mixtures, however, most probably also occur during phreatomagmatic events in nature. Mixtures of water and magma on a large scale may be modelled by combination of small elements. Earlier experimental studies of thermal explosions were carried out with the use of metal melts nearly exclusively. Therefore, a carbonate melt (approx. 0.3 kg of 1:1 mass ratio Na 2CO 3 / K 2CO 3) was used for initial experimental series because of easy handling and more "magma similarity". By injection of water into this melt explosive mixtures were produced and ignited (self-triggering). Explosive interactions occurred in a wide melt-temperature range (720 to 1040C). At melt temperatures exceeding 1000C, CO 2 increasingly degassed. Presence of non-condensible gas bubbles in the melt strongly reduced the explosivity. The intensity of explosions only slightly increased with higher melt temperatures but strongly increased with higher water injection velocities, because of more intensive mixing. A minimum injection velocity was found to be approx. 0.7 m s -1. Experiments with silicate melts, derived from diverse remelted volcanic rocks were carried out with a slightly modified set-up. Explosions were ignited by an additional trigger: a shock wave of approx. 8 J. In volcanic systems, shock waves of this magnitude are abundant (volcanic tremor, etc.). Strong explosions with silicate melts were produced at melt temperatures between 1350 and 1750C. The produced explosions exerted repulsion forces of up to 24,000 N with a typical pulse duration of 1 ms (carbonate melt) resp. 1.5 ms (silicate melts). The ejection velocity was found to be in a range between 200 and 400 m s -1. Explosion energy values up to 500 J were calculated. The maximum explosion pressure was calculated to be in the range between 10 and 100 MPa. Only part of the melt (so-called interactive melt) reacts explosively with injected water. Most of the melt is passively ejected by and after the thermal explosion. Different fragmentation processes result in specific grain size and grain shape populations that can be distinguished from each other. Particles resulting from the fine fragmentation process that precedes and causes the thermal explosion are characterized by angular to subrounded shapes and grain sizes ranging from 20 ?m to 180 ?m. The amount of interactive melt is proportional to the intensity of the explosion. The maximum amount of water vapourized at the explosive interaction (so-called interactive water) was estimated. Thus, the water/melt mass ratio for explosive interactions could be calculated. The values range between {1}/{25} and {1}/{35} (carbonate melt) resp. between {1}/{6} and {1}/{25} (silicate melts).

  4. 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.

  5. 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.

  6. 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.

  7. Discriminating between explosions and earthquakes

    NASA Astrophysics Data System (ADS)

    Cho, Kwang-Hyun

    2014-12-01

    Earthquake, explosion, and a nuclear test data are compared with forward modeling and band-pass filtered surface wave amplitude data for exploring methodologies to improve earthquake-explosion discrimination. The proposed discrimination method is based on the solutions of a double integral transformation in the wavenumber and frequency domains. Recorded explosion data on June 26, 2001 (39.212°N, 125.383°E) and October 30, 2001 (38.748°N, 125.267°E), a nuclear test on October 9, 2006 (41.275°N, 129.095°E), and two earthquakes on April 14, 2002 (39.207°N, 125.686°E) and June 7, 2002 (38.703°N, 125.638°E), all in North Korea, are used to discriminate between explosions and earthquakes by seismic wave analysis and numerical modeling. The explosion signal is characterized by first P waves with higher energy than that of S waves. Rg waves are clearly dominant at 0.05-0.5 Hz in the explosion data but not in the earthquake data. This feature is attributed to the dominant P waves in the explosion and their coupling with the SH components.

  8. Explosive detection research and development

    SciTech Connect

    Malotky, L.O.

    1988-01-01

    The detection of explosives carried by a passenger or included in checked baggage is a priority objective of the Federal Aviation Administration's (FAA) Security Research and Development Program. Significant accomplishments have been made in the detection of explosives in checked baggage. A technology, thermal neutron analysis, has been developed and tested extensively in airports with actual passenger baggage. The screening of people for explosives is also progressing with laboratory testing underway of an integrated passenger screening portal. The portal is designed to extract and detect not only the more volatile explosives but also the low-vapor-pressure military explosives. In addition to these two mature technologies, the FAA is also funding research in new technologies for bulk and vapor detection of explosives to identify and refine approaches which will be more efficient and effective. The ultimate objective is to field systems to protect the traveling public from terrorist-placed explosives without interrupting the free flow of people and materials we have grown to expect.

  9. Radiologic diagnosis of explosion casualties.

    PubMed

    Eastridge, Brian J; Blackbourne, Lorne; Wade, Charles E; Holcomb, John B

    2008-01-01

    The threat of terrorist events on domestic soil remains an ever-present risk. Despite the notoriety of unconventional weapons, the mainstay in the armament of the terrorist organization is the conventional explosive. Conventional explosives are easily weaponized and readily obtainable, and the recipes are widely available over the Internet. According to the US Department of State and the Federal Bureau of Investigation, over one half of the global terrorist events involve explosions, averaging two explosive events per day worldwide in 2005 (Terrorism Research Center. Available at www.terrorism.com. Accessed April 1, 2007). The Future of Emergency Care in the United States Health System: Emergency Medical Services at the Crossroads, published by the Institute of Medicine, states that explosions were the most common cause of injuries associated with terrorism (Institute of Medicine Report: The Future of Emergency Care in the United States Health System: Emergency Medical Services at the Crossroads. Washington DC: National Academic Press, 2007). Explosive events have the potential to inflict numerous casualties with multiple injuries. The complexity of this scenario is exacerbated by the fact that few providers or medical facilities have experience with mass casualty events in which human and material resources can be rapidly overwhelmed. Care of explosive-related injury is based on same principles as that of standard trauma management paradigms. The basic difference between explosion-related injury and other injury mechanisms are the number of patients and multiplicity of injuries, which require a higher allocation of resources. With this caveat, the appropriate utilization of radiology resources has the potential to impact in-hospital diagnosis and triage and is an essential element in optimizing the management of the explosive-injured patients. PMID:19069034

  10. The evolution of microstructural changes in pressed HMX explosives

    SciTech Connect

    Skidmore, C.B.; Phillips, D.S.; Howe, P.M.; Mang, J.T.; Romero, J.A.

    1998-12-31

    Recently developed techniques for investigating the microstructure of plastic-bonded explosives have been applied to HMX explosives pressed to various levels of porosity. Microstructural changes in PBX 9501 area followed from the early stages of prill consolidation through typical density to very low porosity (0.6%). As porosity is reduced, the following sequence is observed. Large inter- and intra-prill voids are eliminated with first damage to HMX crystals occurring at prill boundaries. This is followed by increased incidence of crystal twinning and cracking. At the lowest porosities, spall pullout artifacts are observed, cracks associated with particle contact points are more obvious, and the results of intercrystalline indentation or intergrowth migration processes are apparent. A comparison is made, at lowest porosities achieved, with PX 9404 and X-0242 (a formulation like PBX 9501 with higher binder volume). Possible implications on porosity trends in shock sensitivity data are discussed.

  11. Noise From Shallow Underwater Explosions

    NASA Astrophysics Data System (ADS)

    Soloway, Alexander G.

    Naval activities such as ordnance disposal, demolition and requisite training, can involve detonation of small explosive charges in shallow water that have the potential to harm nearby marine life. Measurements of the underwater sound generated by sub-surface explosions were collected as part of a naval training exercise. In this thesis the noise levels from these explosions will be investigated using peak pressure, sound exposure level and energy spectral density. Measurements of very-low frequency Scholte interface waves will also be presented and used to investigate elastic parameters in the sediment.

  12. 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.

  13. Donor free radical explosive composition

    DOEpatents

    Walker, Franklin E. [15 Way Points Rd., Danville, CA 94526; Wasley, Richard J. [4290 Colgate Way, Livermore, CA 94550

    1980-04-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a donor additive comprising an organic compound or mixture of organic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and which is not an explosive, or an inorganic compound or mixture of inorganic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and selected from ammonium or alkali metal persulfates.

  14. Light metal explosives and propellants

    DOEpatents

    Wood, Lowell L.; Ishikawa, Muriel Y.; Nuckolls, John H.; Pagoria, Phillip F.; Viecelli, James A.

    2005-04-05

    Disclosed herein are light metal explosives, pyrotechnics and propellants (LME&Ps) comprising a light metal component such as Li, B, Be or their hydrides or intermetallic compounds and alloys containing them and an oxidizer component containing a classic explosive, such as CL-20, or a non-explosive oxidizer, such as lithium perchlorate, or combinations thereof. LME&P formulations may have light metal particles and oxidizer particles ranging in size from 0.01 .mu.m to 1000 .mu.m.

  15. Explosive Microsphere Particle Standards for Trace Explosive Detection Instruments

    NASA Astrophysics Data System (ADS)

    Staymates, Matthew; Fletcher, Robert; Gillen, Greg

    2007-11-01

    Increases in Homeland Security measures have led to a substantial deployment of trace explosive detection systems within the United States and US embassies around the world. One such system is a walk-through portal which aerodynamically screens people for trace explosive particles. Another system is a benchtop instrument that can detect explosives from swipes used to collect explosive particles from surfaces of luggage and clothing. The National Institute of Standards and Technology is involved in a chemical metrology program to support the operational deployment and effective utilization of trace explosive and narcotic detection devices and is working to develop a measurement infrastructure to optimize, calibrate and standardize these instruments. Well characterized test materials are essential for validating the performance of these systems. Particle size, chemical composition, and detector response are particularly important. Here, we describe one method for producing monodisperse polymer microspheres encapsulating trace explosives, simulants, and narcotics using a sonicated co-flow Berkland nozzle. The nozzle creates uniform droplets that undergo an oil/water emulsion process and cure to form hardened microspheres containing the desired analyte. Issues such as particle size, particle uniformity and levels of analyte composition will be discussed.

  16. 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.

  17. An assessment of the flammability and explosion potential of transuranic waste

    SciTech Connect

    Silva, M.

    1991-06-01

    The explosion potential of transuranic (TRU) waste, destined for the Waste Isolation Pilot (WIPP), was recently examined in EEG-45. That investigation focused on the volatile organic compounds (VOCs) in the waste, particularly acetone, and concluded that an explosion due to the VOCs was unlikely. Recent evidence raises serious concerns about drums containing mixed radioactive hazardous waste bound for the WIPP. Static electricity generated by the plastic bags represents a potential ignition source for other fuels, such as methane gas or hydrogen gas, during transportation and during the test phase. The potential danger of explosion due to hydrogen gas or methane gas generation has not yet been resolved. This report investigates that potential hazard and examines documented ignitions, fires, explosions and incidents of overpressurization of containers at generating and storage sites planning to send transuranic waste to the WIPP for disposal. 68 refs., 6 figs.

  18. The Cambrian explosion.

    PubMed

    Briggs, Derek E G

    2015-10-01

    The sudden appearance of fossils that marks the so-called 'Cambrian explosion' has intrigued and exercised biologists since Darwin's time. In On the Origin of Species, Darwin made it clear that he believed that ancestral forms 'lived long before' their first fossil representatives. While he considered such an invisible record necessary to explain the level of complexity already seen in the fossils of early trilobites, Darwin was at a loss to explain why there were no corresponding fossils of these earlier forms. In chapter 9 of the Origin, entitled 'On the imperfection of the geological record', he emphasized the 'poorness of our palaeontological collections' and stated categorically that 'no organism wholly soft can be preserved'. Fortunately much has been discovered in the last 150 years, not least multiple examples of Cambrian and Precambrian soft-bodied fossils. We now know that the sudden appearance of fossils in the Cambrian (541-485 million years ago) is real and not an artefact of an imperfect fossil record: rapid diversification of animals coincided with the evolution of biomineralized shells. And although fossils in earlier rocks are rare, they are not absent: their rarity reflects the low diversity of life at this time, as well as the low preservation potential of Precambrian organisms (see Primer by Butterfield, in this issue). PMID:26439348

  19. Furball Explosive Breakout Test

    SciTech Connect

    Carroll, Joshua David

    2015-08-05

    For more than 30 years the Onionskin test has been the primary way to study the surface breakout of a detonation wave. Currently the Onionskin test allows for only a small, one dimensional, slice of the explosive in question to be observed. Asymmetrical features are not observable with the Onionskin test and its one dimensional view. As a result, in 2011, preliminary designs for the Hairball and Furball were developed then tested. The Hairball used shorting pins connected to an oscilloscope to determine the arrival time at 24 discrete points. This limited number of data points, caused by the limited number of oscilloscope channels, ultimately led to the Hairball’s demise. Following this, the Furball was developed to increase the number of data points collected. Instead of shorting pins the Furball uses fiber optics imaged by a streak camera to determine the detonation wave arrival time for each point. The original design was able to capture the detonation wave’s arrival time at 205 discrete points with the ability to increase the number of data points if necessary.

  20. Explosive Contagion in Networks

    PubMed Central

    Gómez-Gardeñes, J.; Lotero, L.; Taraskin, S. N.; Pérez-Reche, F. J.

    2016-01-01

    The spread of social phenomena such as behaviors, ideas or products is an ubiquitous but remarkably complex phenomenon. A successful avenue to study the spread of social phenomena relies on epidemic models by establishing analogies between the transmission of social phenomena and infectious diseases. Such models typically assume simple social interactions restricted to pairs of individuals; effects of the context are often neglected. Here we show that local synergistic effects associated with acquaintances of pairs of individuals can have striking consequences on the spread of social phenomena at large scales. The most interesting predictions are found for a scenario in which the contagion ability of a spreader decreases with the number of ignorant individuals surrounding the target ignorant. This mechanism mimics ubiquitous situations in which the willingness of individuals to adopt a new product depends not only on the intrinsic value of the product but also on whether his acquaintances will adopt this product or not. In these situations, we show that the typically smooth (second order) transitions towards large social contagion become explosive (first order). The proposed synergistic mechanisms therefore explain why ideas, rumours or products can suddenly and sometimes unexpectedly catch on. PMID:26819191

  1. Explosive Contagion in Networks

    NASA Astrophysics Data System (ADS)

    Gómez-Gardeñes, J.; Lotero, L.; Taraskin, S. N.; Pérez-Reche, F. J.

    2016-01-01

    The spread of social phenomena such as behaviors, ideas or products is an ubiquitous but remarkably complex phenomenon. A successful avenue to study the spread of social phenomena relies on epidemic models by establishing analogies between the transmission of social phenomena and infectious diseases. Such models typically assume simple social interactions restricted to pairs of individuals; effects of the context are often neglected. Here we show that local synergistic effects associated with acquaintances of pairs of individuals can have striking consequences on the spread of social phenomena at large scales. The most interesting predictions are found for a scenario in which the contagion ability of a spreader decreases with the number of ignorant individuals surrounding the target ignorant. This mechanism mimics ubiquitous situations in which the willingness of individuals to adopt a new product depends not only on the intrinsic value of the product but also on whether his acquaintances will adopt this product or not. In these situations, we show that the typically smooth (second order) transitions towards large social contagion become explosive (first order). The proposed synergistic mechanisms therefore explain why ideas, rumours or products can suddenly and sometimes unexpectedly catch on.

  2. Explosive actuated valves

    DOEpatents

    Cobb, Jr., Lawrence L.

    1983-01-01

    1. A device of the character described comprising the combination of a generally tubular housing having an end portion forming a chamber to receive the sensitive portion of an explosive squib, a plunger within said housing having an end portion exposed to said chamber, squib retaining means for engaging said housing and a said squib to releasably maintain the squib in close proximity to said plunger end portion including a retaining ring of fusible material spaced outwardly from and encircling at least part of a said squib and part of its sensitive portion for reception of heat from an external source prior to appreciable reception thereof by the sensitive portion of the squib, an annular compression spring bearing at one end against said housing for urging at least a portion of the squib retaining means and a said squib away from said housing and from said plunger end portion upon subjection of the fusible material to heat sufficient to melt at least a portion thereof, and guide means for said spring to maintain even expansion thereof as a said squib is being urged away from said housing.

  3. Explosive actuated valve

    DOEpatents

    Byrne, Kenneth G.

    1983-01-01

    1. A device of the character described comprising the combination of a housing having an elongate bore and including a shoulder extending inwardly into said bore, a single elongate movable plunger disposed in said bore including an outwardly extending flange adjacent one end thereof overlying said shoulder, normally open conduit means having an inlet and an outlet perpendicularly piercing said housing intermediate said shoulder and said flange and including an intermediate portion intersecting and normally openly communicating with said bore at said shoulder, normally closed conduit means piercing said housing and intersecting said bore at a location spaced from said normally open conduit means, said elongate plunger including a shearing edge adjacent the other end thereof normally disposed intermediate both of said conduit means and overlying a portion of said normally closed conduit means, a deformable member carried by said plunger intermediate said flange and said shoulder and normally spaced from and overlying the intermediate portion of said normally open conduit means, and means on the housing communicating with the bore to retain an explosive actuator for moving said plunger to force the deformable member against the shoulder and extrude a portion of the deformable member out of said bore into portions of the normally open conduit means for plugging the same and to effect the opening of said normally closed conduit means by the plunger shearing edge substantially concomitantly with the plugging of the normally open conduit means.

  4. Explosive Contagion in Networks.

    PubMed

    Gómez-Gardeñes, J; Lotero, L; Taraskin, S N; Pérez-Reche, F J

    2016-01-01

    The spread of social phenomena such as behaviors, ideas or products is an ubiquitous but remarkably complex phenomenon. A successful avenue to study the spread of social phenomena relies on epidemic models by establishing analogies between the transmission of social phenomena and infectious diseases. Such models typically assume simple social interactions restricted to pairs of individuals; effects of the context are often neglected. Here we show that local synergistic effects associated with acquaintances of pairs of individuals can have striking consequences on the spread of social phenomena at large scales. The most interesting predictions are found for a scenario in which the contagion ability of a spreader decreases with the number of ignorant individuals surrounding the target ignorant. This mechanism mimics ubiquitous situations in which the willingness of individuals to adopt a new product depends not only on the intrinsic value of the product but also on whether his acquaintances will adopt this product or not. In these situations, we show that the typically smooth (second order) transitions towards large social contagion become explosive (first order). The proposed synergistic mechanisms therefore explain why ideas, rumours or products can suddenly and sometimes unexpectedly catch on. PMID:26819191

  5. Detecting plastics in seedcotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The US cotton industry wants to increase market share and value by supplying pure cotton. Removing contamination requires developing a means to detect plastics in seedcotton. This study was conducted to determine if Ion Mobility Spectrometry (IMS) could be used to find small amounts of plastic in ...

  6. Detecting plastics in seedcotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To increase global market share and value the US cotton industry needs to supply cotton lint that is free of contamination. Removing plastic contamination first requires developing a means to detect plastics in seedcotton. This study was conducted to validate a custom Ion Mobility Spectrometer (IM...

  7. The challenge of improvised explosives

    SciTech Connect

    Maienschein, Jon L.

    2012-06-14

    Energetic materials have been developed for decades, and indeed centuries, with a common set of goals in mind. Performance (as a detonating explosive, a propellant, or a pyrotechnic) has always been key, equally important have been the attributes of safety, stability, and reproducibility. Research and development with those goals has led to the set of energetic materials commonly used today. In the past few decades, the adoption and use of improvised explosives in attacks by terrorists or third-world parties has led to many questions about these materials, e.g., how they may be made, what threat they pose to the intended target, how to handle them safely, and how to detect them. The unfortunate advent of improvised explosives has opened the door for research into these materials, and there are active programs in many countries. I will discuss issues and opportunities facing research into improvised explosives.

  8. Explosive Spot Joining of Metals

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J. (Inventor); Perry, Ronnie B. (Inventor)

    1997-01-01

    The invention is an apparatus and method for wire splicing using an explosive joining process. The apparatus consists of a prebend, U-shaped strap of metal that slides over prepositioned wires. A standoff means separates the wires from the strap before joining. An adhesive means holds two ribbon explosives in position centered over the U-shaped strap. A detonating means connects to the ribbon explosives. The process involves spreading strands of each wire to be joined into a flat plane. The process then requires alternating each strand in alignment to form a mesh-like arrangement with an overlapped area. The strap slides over the strands of the wires. and the standoff means is positioned between the two surfaces. The detonating means then initiates the ribbon explosives that drive the strap to accomplish a high velocity. angular collision between the mating surfaces. This collision creates surface melts and collision bonding resulting in electron-sharing linkups.

  9. Explosive plane-wave lens

    DOEpatents

    Marsh, S.P.

    1988-03-08

    An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive. 4 figs.

  10. Explosive plane-wave lens

    DOEpatents

    Marsh, S.P.

    1987-03-12

    An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive. 3 figs., 3 tabs.

  11. Explosives characterization in terahertz range

    NASA Astrophysics Data System (ADS)

    Maestrojuán, I.; Palacios, I.; Etayo, D.; Iriarte, J. C.; Teniente, J.; Ederra, I.; Gonzalo, R.

    2011-11-01

    A Thz spectral characterization of the behaviour of different explosives is presented in this paper. This characterization will be done in the frequency range from 20 GHz to 4 THz using a Teraview Spectra 3000. This system has a capacity of measuring from 20 GHz to 4 THz fed by a laser source. With the Teraview Spectra 3000 equipment will be possible to calculate the refractive index, the absorbance and other important parameters of the explosive samples. With this study it will be possible to characterize some of the most common used explosives, i.e., gun explosive, gunpowder mine, pent, TNT, RDX, etc, and it will allow to determine their electromagnetic peculiarities in order to design a future imaging system that allow detecting them in security and defense sectors.

  12. Molecular clocks and explosive radiations.

    PubMed

    Bromham, Lindell

    2003-01-01

    Molecular data are ideal for exploring evolutionary history because of its universality, stochasticity, and abundance. These features provide a means of exploring the evolutionary history of all organisms (including those that do not tend to leave fossils), potentially within a statistical framework that allows testing of evolutionary hypotheses. However, the discrepancy between molecular and paleontological dates for three key "explosive" radiations inferred from the fossil record--the Cambrian explosion of animal phyla and the post-KT radiations of modern orders of mammals and birds--have led to a reexamination of the assumptions on which molecular dates are based. Could variation in the rate of molecular evolution, perhaps associated with "explosive" radiations, cause overestimation of diversification dates? Here I examine four hypothetical causes of fast molecular rates in explosive radiations--body size, morphological rate, speciation rate, and ecological diversification--using available empirical evidence on patterns of variation in rate of molecular evolution. PMID:15008399

  13. Explosive plane-wave lens

    DOEpatents

    Marsh, Stanley P.

    1988-01-01

    An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive.

  14. The challenge of improvised explosives

    DOE PAGESBeta

    Maienschein, Jon L.

    2012-06-14

    Energetic materials have been developed for decades, and indeed centuries, with a common set of goals in mind. Performance (as a detonating explosive, a propellant, or a pyrotechnic) has always been key, equally important have been the attributes of safety, stability, and reproducibility. Research and development with those goals has led to the set of energetic materials commonly used today. In the past few decades, the adoption and use of improvised explosives in attacks by terrorists or third-world parties has led to many questions about these materials, e.g., how they may be made, what threat they pose to the intendedmore » target, how to handle them safely, and how to detect them. The unfortunate advent of improvised explosives has opened the door for research into these materials, and there are active programs in many countries. I will discuss issues and opportunities facing research into improvised explosives.« less

  15. Explosion modelling for complex geometries

    NASA Astrophysics Data System (ADS)

    Nehzat, Naser

    A literature review suggested that the combined effects of fuel reactivity, obstacle density, ignition strength, and confinement result in flame acceleration and subsequent pressure build-up during a vapour cloud explosion (VCE). Models for the prediction of propagating flames in hazardous areas, such as coal mines, oil platforms, storage and process chemical areas etc. fall into two classes. One class involves use of Computation Fluid Dynamics (CFD). This approach has been utilised by several researchers. The other approach relies upon a lumped parameter approach as developed by Baker (1983). The former approach is restricted by the appropriateness of sub-models and numerical stability requirements inherent in the computational solution. The latter approach raises significant questions regarding the validity of the simplification involved in representing the complexities of a propagating explosion. This study was conducted to investigate and improve the Computational Fluid Dynamic (CFD) code EXPLODE which has been developed by Green et al., (1993) for use on practical gas explosion hazard assessments. The code employs a numerical method for solving partial differential equations by using finite volume techniques. Verification exercises, involving comparison with analytical solutions for the classical shock-tube and with experimental (small-scale, medium and large-scale) results, demonstrate the accuracy of the code and the new combustion models but also identify differences between predictions and the experimental results. The project has resulted in a developed version of the code (EXPLODE2) with new combustion models for simulating gas explosions. Additional features of this program include the physical models necessary to simulate the combustion process using alternative combustion models, improvement to the numerical accuracy and robustness of the code, and special input for simulation of different gas explosions. The present code has the capability of predicting venting failures by different combustion models, something that was not shown clearly in the open literature by the previous numerical studies in gas explosions. The work accomplished in this research was undertaken put of the need for an objective method to predict explosion parameters for vapour cloud explosions in confined and semi-confined areas. The thesis describes basic features of a numerical explosion model that has been developed for predicting explosion pressure and flame propagation in confined and semi confined regions. The validation of the code and combustion models against analytical and several experimental data supports the code and its combustion models as a good tool for prediction of VCEs. This thesis starts with a basic description of explosion, assessment methods, theory, turbulent combustion, different combustion models and concludes with a discussion of the results and areas of uncertainty.

  16. 30 CFR 7.306 - Explosion tests.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Explosion tests. 7.306 Section 7.306 Mineral... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Electric Motor Assemblies § 7.306 Explosion tests. (a) The following shall be used for conducting an explosion test: (1) An explosion test chamber...

  17. 36 CFR 2.38 - Explosives.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Explosives. 2.38 Section 2.38... PROTECTION, PUBLIC USE AND RECREATION § 2.38 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and...

  18. 36 CFR 1002.38 - Explosives.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Explosives. 1002.38 Section... RECREATION § 1002.38 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and conditions of a permit....

  19. 30 CFR 77.1301 - Explosives; magazines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Explosives; magazines. 77.1301 Section 77.1301... MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Explosives and Blasting § 77.1301 Explosives; magazines. (a) Detonators and explosives other than blasting...

  20. 32 CFR 234.9 - Explosives.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 2 2013-07-01 2013-07-01 false Explosives. 234.9 Section 234.9 National Defense... PENTAGON RESERVATION § 234.9 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and conditions of...

  1. 32 CFR 234.9 - Explosives.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 2 2014-07-01 2014-07-01 false Explosives. 234.9 Section 234.9 National Defense... PENTAGON RESERVATION § 234.9 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and conditions of...

  2. 32 CFR 234.9 - Explosives.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 2 2012-07-01 2012-07-01 false Explosives. 234.9 Section 234.9 National Defense... PENTAGON RESERVATION § 234.9 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and conditions of...

  3. 32 CFR 1903.9 - Explosives.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Explosives. 1903.9 Section 1903.9 National... INSTALLATIONS § 1903.9 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents, ammunition or explosive materials is prohibited on any Agency installation, except as authorized by...

  4. 36 CFR 2.38 - Explosives.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Explosives. 2.38 Section 2.38... PROTECTION, PUBLIC USE AND RECREATION § 2.38 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and...

  5. 14 CFR 420.63 - Explosive siting.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Explosive siting. 420.63 Section 420.63... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Responsibilities of a Licensee § 420.63 Explosive... configuration of the launch site follows its explosive site plan, and the licensee's explosive site...

  6. 36 CFR 1002.38 - Explosives.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Explosives. 1002.38 Section... RECREATION § 1002.38 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and conditions of a permit....

  7. 36 CFR 1002.38 - Explosives.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Explosives. 1002.38 Section... RECREATION § 1002.38 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and conditions of a permit....

  8. 36 CFR 2.38 - Explosives.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Explosives. 2.38 Section 2.38... PROTECTION, PUBLIC USE AND RECREATION § 2.38 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and...

  9. 30 CFR 77.1301 - Explosives; magazines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Explosives; magazines. 77.1301 Section 77.1301... MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Explosives and Blasting § 77.1301 Explosives; magazines. (a) Detonators and explosives other than blasting...

  10. 30 CFR 77.1301 - Explosives; magazines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Explosives; magazines. 77.1301 Section 77.1301... MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Explosives and Blasting § 77.1301 Explosives; magazines. (a) Detonators and explosives other than blasting...

  11. 32 CFR 1903.9 - Explosives.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Explosives. 1903.9 Section 1903.9 National... INSTALLATIONS § 1903.9 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents, ammunition or explosive materials is prohibited on any Agency installation, except as authorized by...

  12. 14 CFR 420.63 - Explosive siting.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Explosive siting. 420.63 Section 420.63... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Responsibilities of a Licensee § 420.63 Explosive... configuration of the launch site follows its explosive site plan, and the licensee's explosive site...

  13. 30 CFR 7.306 - Explosion tests.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Explosion tests. 7.306 Section 7.306 Mineral... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Electric Motor Assemblies § 7.306 Explosion tests. (a) The following shall be used for conducting an explosion test: (1) An explosion test chamber...

  14. 30 CFR 77.1301 - Explosives; magazines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Explosives; magazines. 77.1301 Section 77.1301... MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Explosives and Blasting § 77.1301 Explosives; magazines. (a) Detonators and explosives other than blasting...

  15. 32 CFR 234.9 - Explosives.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 2 2011-07-01 2011-07-01 false Explosives. 234.9 Section 234.9 National Defense... PENTAGON RESERVATION § 234.9 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and conditions of...

  16. 36 CFR 1002.38 - Explosives.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Explosives. 1002.38 Section... RECREATION § 1002.38 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and conditions of a permit....

  17. 36 CFR 1002.38 - Explosives.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Explosives. 1002.38 Section... RECREATION § 1002.38 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and conditions of a permit....

  18. 36 CFR 2.38 - Explosives.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Explosives. 2.38 Section 2.38... PROTECTION, PUBLIC USE AND RECREATION § 2.38 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and...

  19. 32 CFR 1903.9 - Explosives.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Explosives. 1903.9 Section 1903.9 National... INSTALLATIONS § 1903.9 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents, ammunition or explosive materials is prohibited on any Agency installation, except as authorized by...

  20. 30 CFR 77.1301 - Explosives; magazines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosives; magazines. 77.1301 Section 77.1301... MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Explosives and Blasting § 77.1301 Explosives; magazines. (a) Detonators and explosives other than blasting...

  1. 32 CFR 234.9 - Explosives.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Explosives. 234.9 Section 234.9 National Defense... PENTAGON RESERVATION § 234.9 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and conditions of...

  2. 36 CFR 2.38 - Explosives.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Explosives. 2.38 Section 2.38... PROTECTION, PUBLIC USE AND RECREATION § 2.38 Explosives. (a) Using, possessing, storing, or transporting explosives, blasting agents or explosive materials is prohibited, except pursuant to the terms and...

  3. A method for introduction of unmarked mutations in the genome of Paracoccus denitrificans: construction of strains with multiple mutations in the genes encoding periplasmic cytochromes c550, c551i, and c553i.

    PubMed Central

    Van Spanning, R J; Wansell, C W; Reijnders, W N; Harms, N; Ras, J; Oltmann, L F; Stouthamer, A H

    1991-01-01

    A new suicide vector, pRVS1, was constructed to facilitate the site-directed introduction of unmarked mutations in the chromosome of Paracoccus denitrificans. The vector was derived from suicide vector pGRPd1, which was equipped with the lacZ gene encoding beta-galactosidase. The reporter gene was found to be a successful screening marker for the discrimination between plasmid integrant strains and mutant strains which had lost the plasmid after homologous recombination. Suicide vectors pGRPd1 and pRVS1 were used in gene replacement techniques for the construction of mutant strains with multiple mutations in the cycA, moxG, and cycB genes encoding the periplasmic cytochromes c550, c551i, and c553i, respectively. Southern analyses of the DNA and protein analyses of the resultant single, double, and triple mutant strains confirmed the correctness of the mutations. The wild type and mutant strains were all able to grow on succinate and choline chloride. In addition, all strains grew on methylamine and displayed wild-type levels of methylamine dehydrogenase activities. cycA mutant strains, however, showed a decreased maximum specific growth rate on the methylamine substrate. The wild-type strain, cycA and cycB mutant strains, and the cycA cycB double mutant strain were able to grow on methanol and showed wild-type levels of methanol dehydrogenase activities. moxG mutant strains failed to grow on methanol and had low levels of methanol dehydrogenase activities. The maximum specific growth rate of the cycA mutant strain on methanol was comparable with that of the wild-type strain. The data indicate the involvement of the soluble cytochromes c in clearly defined electron transport routes. Images FIG. 3 FIG. 4 PMID:1657872

  4. Track recording plastic compositions

    NASA Technical Reports Server (NTRS)

    Tarle, Gregory (Inventor)

    1983-01-01

    Improved nuclear track recording plastic compositions are provided which exhibit greatly decreased surface roughness when etched to produce visible tracks of energetic nuclear particles which have passed into and/or through said plastic. The improved compositions incorporate a small quantity of a phthalic acid ester into the major plastic component which is derived from the polymerization of monomeric di-ethylene glycol bis allyl carbonate. Di-substituted phthalic acid esters are preferred as the added component, with the further perference that the ester substituent has a chain length of 2 or more carbon atoms. The inclusion of the phthalic acid ester to an extent of from about 1-2% by weight of the plastic compositions is sufficient to drastically reduce the surface roughness ordinarily produced when the track recording plastic is contacted by etchants.

  5. Anaerobic Metabolism and Bioremediation of Explosives-Contaminated Soil

    NASA Astrophysics Data System (ADS)

    Boopathy, Raj

    Nitroaromatic compounds pollute soil, water, and food via use of pesticides, plastics, pharmaceuticals, landfill dumping of industrial wastes, and the military use of explosives. Biotransformation of trinitrotoluene and other nitroaromatics by aerobic bacteria in the laboratory has been frequently reported, but the anaerobic bacterial metabolism of nitroaromatics has not been studied as extensively perhaps due to the difficulty in working with anaerobic cultures and the slow growth of anaerobes. Sulfate-reducing and methanogenic bacteria can metabolize nitroaromatic compounds under anaerobic conditions if appropriate electron donors and electron acceptors are present in the environment.

  6. Optimized thermal desorption for improved sensitivity in trace explosives detection by ion mobility spectrometry.

    PubMed

    Najarro, Marcela; Dávila Morris, Melissa E; Staymates, Matthew E; Fletcher, Robert; Gillen, Greg

    2012-06-01

    In this work we evaluate the influence of thermal desorber temperature on the analytical response of a swipe-based thermal desorption ion mobility spectrometer (IMS) for detection of trace explosives. IMS response for several common high explosives ranging from 0.1 ng to 100 ng was measured over a thermal desorber temperature range from 60 °C to 280 °C. Most of the explosives examined demonstrated a well-defined maximum IMS signal response at a temperature slightly below the melting point. Optimal temperatures, giving the highest IMS peak intensity, were 80 °C for trinitrotoluene (TNT), 100 °C for pentaerythritol tetranitrate (PETN), 160 °C for cyclotrimethylenetrinitramine (RDX) and 200 °C for cyclotetramethylenetetranitramine (HMX). By modifying the desorber temperature, we were able to increase cumulative IMS signal by a factor of 5 for TNT and HMX, and by a factor of 10 for RDX and PETN. Similar signal enhancements were observed for the same compounds formulated as plastic-bonded explosives (Composition 4 (C-4), Detasheet, and Semtex). In addition, mixtures of the explosives exhibited similar enhancements in analyte peak intensities. The increases in sensitivity were obtained at the expense of increased analysis times of up to 20 seconds. A slow sample heating rate as well as slower vapor-phase analyte introduction rate caused by low-temperature desorption enhanced the analytical sensitivity of individual explosives, plastic-bonded explosives, and explosives mixtures by IMS. Several possible mechanisms that can affect IMS signal response were investigated such as thermal degradation of the analytes, ionization efficiency, competitive ionization from background, and aerosol emission. PMID:22498665

  7. System for analysis of explosives

    SciTech Connect

    Haas, Jeffrey S.

    2010-06-29

    A system for analysis of explosives. Samples are spotted on a thin layer chromatography plate. Multi-component explosives standards are spotted on the thin layer chromatography plate. The thin layer chromatography plate is dipped in a solvent mixture and chromatography is allowed to proceed. The thin layer chromatography plate is dipped in reagent 1. The thin layer chromatography plate is heated. The thin layer chromatography plate is dipped in reagent 2.

  8. Net Catches Debris From Explosion

    NASA Technical Reports Server (NTRS)

    Kahn, Jon B.; Schneider, William C.

    1992-01-01

    Device restrains fragments and absorbs their kinetic energy. Net of stitched webbing folds compactly over honeycomb plug. Attaches to frame mounted on wall around rectangular area to be cut out by explosion. Honeycomb panel absorbs debris from explosion and crumples into net. Dissipates energy by ripping about 9 in. of stitched net. Developed for emergency escape system in Space Shuttle, adaptable to restraint belts for vehicles; subjecting passengers to more gradual deceleration and less shock.

  9. The characterization and evaluation of accidental explosions

    NASA Technical Reports Server (NTRS)

    Strehlow, R. A.; Baker, W. E.

    1975-01-01

    Accidental explosions are discussed from a number of viewpoints. First, all accidental explosions, intentional explosions and natural explosions are characterized by type. Second, the nature of the blast wave produced by an ideal (point source or HE) explosion is discussed to form a basis for describing how other explosion processes yield deviations from ideal blast wave behavior. The current status blast damage mechanism evaluation is also discussed. Third, the current status of our understanding of each different category of accidental explosions is discussed in some detail.

  10. 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.

  11. Microbial remediation of explosive waste.

    PubMed

    Singh, Baljinder; Kaur, Jagdeep; Singh, Kashmir

    2012-05-01

    Explosives are synthesized globally mainly for military munitions. Nitrate esters, such as GTN and PETN, nitroaromatics like TNP and TNT and nitramines with RDX, HMX and CL20, are the main class of explosives used. Their use has resulted in severe contamination of environment and strategies are now being developed to clean these substances in an economical and eco-friendly manner. The incredible versatility inherited in microbes has rendered these explosives as a part of the biogeochemical cycle. Several microbes catalyze mineralization and/or nonspecific transformation of explosive waste either by aerobic or anaerobic processes. It is likely that ongoing genetic adaptation, with the recruitment of silent sequences into functional catabolic routes and evolution of substrate range by mutations in structural genes, will further enhance the catabolic potential of bacteria toward explosives and ultimately contribute to cleansing the environment of these toxic and recalcitrant chemicals. This review summarizes information on the biodegradation and biotransformation pathways of several important explosives. Isolation, characterization, utilization and manipulation of the major detoxifying enzymes and the molecular basis of degradation are also discussed. This may be useful in developing safer and economic microbiological methods for clean up of soil and water contaminated with such compounds. The necessity of further investigations concerning the microbial metabolism of these substances is also discussed. PMID:22497284

  12. Plastic Surgery for Ethnic Patients

    MedlinePlus

    ... Home > News > Plastic Surgery for Ethnic Patients Briefing Paper: Plastic Surgery for Ethnic Patients More than 3. ... 2067-2071. Share Related Links Plastic Surgery Briefing Papers Menu Cosmetic Reconstructive Patient Safety Before & After Find ...

  13. Dynamic compression of solid HMX-based explosives under ramp wave loading

    NASA Astrophysics Data System (ADS)

    Wang, G. J.; Cai, J. T.; Zhang, H. P.; Zhao, F.; Tan, F. L.; Wu, G.

    2012-11-01

    By means of the new techniques of magnetically driven quasi-isentropic compression based on compact capacitor bank facility CQ-1.5 developed by us, the dynamic compression of two mixed HMX-based plastic bonded explosives (PBX) explosives is researched under ramp wave loading. A pressure of 5-8 GPa over 600-800 ns is realized on explosive samples by optimizing loading electrodes and controlling charging voltages of CQ-1.5. And loading strain rates vary from 105 1/s to 106 1/s along the thickness of explosive samples. For experiments, the particle velocities of interface between explosive samples with different thicknesses and LiF windows are measured to determine material response by a displacement interferometry technique of Doppler pins system (DPS), and the experimental compression isentropes of researched explosives are obtained using the data processing method of backward integration and Lagrangian analysis for quasi-isentropic compression experiments, which are in agreement with the theoretical isentropes based on Mie-Grüneisen equation of state (EOS) and the results by Baer. For simulations, one-dimensional hydrodynamics code SSS is used to analyze the dynamic process, and the calculated results of particle velocity of interfaces are consistent with the experimental ones. Finally, one of the explosive constituents, the binder fluoride rubber F2311, is also investigated using this technique, and some properties under ramp wave loading are gained.

  14. Development of SRM 2907 trace terrorist explosives simulants for the detection of Semtex and triacetone triperoxide.

    PubMed

    MacCrehan, William; Moore, Stephanie; Hancock, Diane

    2011-12-01

    Effective and accurate detection of trace explosives is crucial in the effort to thwart terrorist explosives attacks. A National Institute of Standards and Technology (NIST) standard reference material (SRM) has been developed for the evaluation of trace explosives detectors that sample by collection of residue particles using swiping or air filtration. SRM 2907 Trace Terrorist Explosives Simulants consists of two materials individually simulating the residues of the plastic explosive Semtex [for pentaerytritol tetranitrate (PETN)] and the improvised explosive triacetone triperoxide (TATP). Unique challenges were encountered in the development of these materials, including the selection of suitable inert substrates, material preparation, thermal stability testing, and analytical method development. Two independent analytical methods based on liquid chromatography with ultraviolet absorbance and mass spectrometric detection, LC-UV and LC/MS, respectively, were developed and used to certify the mass fractions of PETN and TATP. These materials were further evaluated for their suitability on a field swipe-sampled trace explosives detectors based on ion mobility spectrometry (IMS). PMID:22004378

  15. 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

  16. Modeling of explosive densensitization by preshocking

    SciTech Connect

    Mader, C.L.

    1986-01-01

    Densensitization of heterogeneous explosives by shocks too weak to initiate propagating detonation occurs because the preshock desensitizes the heterogeneous explosive by closing the voids and making it more homogeneous. A higher pressure second shock has a lower temperature in the multiple shocked explosive than in single shocked explosive. The multiple shock temperature may be low enough to cause a detonation wave to fail to propagate through the preshocked explosive. 9 refs., 8figs., 2 tabs.

  17. Detection and mapping of trace explosives on surfaces under ambient conditions using multiphoton electron extraction spectroscopy (MEES).

    PubMed

    Tang, Shisong; Vinerot, Nataly; Fisher, Danny; Bulatov, Valery; Yavetz-Chen, Yehuda; Schechter, Israel

    2016-08-01

    Multiphoton electron extraction spectroscopy (MEES) is an analytical method in which UV laser pulses are utilized for extracting electrons from solid surfaces in multiphoton processes under ambient conditions. Counting the emitted electrons as a function of laser wavelength results in detailed spectral features, which can be used for material identification. The method has been applied to detection of trace explosives on a variety of surfaces. Detection was possible on dusty swabs spiked with explosives and also in the standard dry-transfer contamination procedure. Plastic explosives could also be detected. The analytical limits of detection (LODs) are in the sub pmole range, which indicates that MEES is one of the most sensitive detection methods for solid surface under ambient conditions. Scanning the surface with the laser allows for its imaging, such that explosives (as well as other materials) can be located. The imaging mode is also useful in forensic applications, such as detection of explosives in human fingerprints. PMID:27216679

  18. The Quiet Explosion

    NASA Astrophysics Data System (ADS)

    2008-07-01

    A European-led team of astronomers are providing hints that a recent supernova may not be as normal as initially thought. Instead, the star that exploded is now understood to have collapsed into a black hole, producing a weak jet, typical of much more violent events, the so-called gamma-ray bursts. The object, SN 2008D, is thus probably among the weakest explosions that produce very fast moving jets. This discovery represents a crucial milestone in the understanding of the most violent phenomena observed in the Universe. Black Hole ESO PR Photo 23a/08 A Galaxy and two Supernovae These striking results, partly based on observations with ESO's Very Large Telescope, will appear tomorrow in Science Express, the online version of Science. Stars that were at birth more massive than about 8 times the mass of our Sun end their relatively short life in a cosmic, cataclysmic firework lighting up the Universe. The outcome is the formation of the densest objects that exist, neutron stars and black holes. When exploding, some of the most massive stars emit a short cry of agony, in the form of a burst of very energetic light, X- or gamma-rays. In the early afternoon (in Europe) of 9 January 2008, the NASA/STFC/ASI Swift telescope discovered serendipitously a 5-minute long burst of X-rays coming from within the spiral galaxy NGC 2770, located 90 million light-years away towards the Lynx constellation. The Swift satellite was studying a supernova that had exploded the previous year in the same galaxy, but the burst of X-rays came from another location, and was soon shown to arise from a different supernova, named SN 2008D. Researchers at the Italian National Institute for Astrophysics (INAF), the Max-Planck Institute for Astrophysics (MPA), ESO, and at various other institutions have observed the supernova at great length. The team is led by Paolo Mazzali of INAF's Padova Observatory and MPA. "What made this event very interesting," says Mazzali, "is that the X-ray signal was very weak and 'soft' [1], very different from a gamma-ray burst and more in line with what is expected from a normal supernova." So, after the supernova was discovered, the team rapidly observed it from the Asiago Observatory in Northern Italy and established that it was a Type Ic supernova. "These are supernovae produced by stars that have lost their hydrogen and helium-rich outermost layers before exploding, and are the only type of supernovae which are associated with (long) gamma-ray bursts," explains Mazzali. "The object thus became even more interesting!" Earlier this year, an independent team of astronomers reported in the journal Nature that SN 2008D is a rather normal supernova. The fact that X-rays were detected was, they said, because for the first time, astronomers were lucky enough to catch the star in the act of exploding. Mazzali and his team think otherwise. "Our observations and modeling show this to be a rather unusual event, to be better understood in terms of an object lying at the boundary between normal supernovae and gamma-ray bursts." The team set up an observational campaign to monitor the evolution of the supernova using both ESO and national telescopes, collecting a large quantity of data. The early behaviour of the supernova indicated that it was a highly energetic event, although not quite as powerful as a gamma-ray burst. After a few days, however, the spectra of the supernova began to change. In particular Helium lines appeared, showing that the progenitor star was not stripped as deeply as supernovae associated with gamma-ray bursts. Over the years, Mazzali and his group have developed theoretical models to analyse the properties of supernovae. When applied to SN2008D, their models indicated that the progenitor star was at birth as massive as 30 times the Sun, but had lost so much mass that at the time of the explosion the star had a mass of only 8-10 solar masses. The likely result of the collapse of such a massive star is a black hole. "Since the masses and energies involved are smaller than in every known gamma-ray burst related supernova, we think that the collapse of the star gave rise to a weak jet, and that the presence of the Helium layer made it even more difficult for the jet to remain collimated, so that when it emerged from the stellar surface the signal was weak," says Massimo Della Valle, co-author. "The scenario we propose implies that gamma-ray burst-like inner engine activity exists in all supernovae that form a black hole," adds co-author Stefano Valenti. "As our X-ray and gamma-ray instruments become more advanced, we are slowly uncovering the very diverse properties of stellar explosions," explains Guido Chincarini, co-author and the Principal Investigator of the Italian research on gamma-ray bursts. "The bright gamma-ray bursts were the easiest to discover, and now we are seeing variations on a theme that link these special events to more normal ones." These are however very important discoveries, as they continue to paint a picture of how massive star end their lives, producing dense objects, and injecting new chemical elements back into the gas from which new stars will be formed.

  19. Recycled ejecta modulating Strombolian explosions

    NASA Astrophysics Data System (ADS)

    Capponi, Antonio; Taddeucci, Jacopo; Scarlato, Piergiorgio; Palladino, Danilo M.

    2016-02-01

    Two main end-members of eruptive regimes are identified from analyses of high-speed videos collected at Stromboli volcano (Italy), based on vent conditions: one where the vent is completely clogged by debris, and a second where the vent is open, without any cover. By detailing the vent processes for each regime, we provide the first account of how the presence of a cover affects eruptive dynamics compared to open-vent explosions. For clogged vents, explosion dynamics are controlled by the amount and grain size of the debris. Fine-grained covers are entirely removed by explosions, favouring the generation of fine ash plumes, while coarse-grained covers are only partially removed by the explosions, involving minor amounts of ash. In both fine- and coarse-grained cases, in-vent ground deformation of the debris reflect variations in the volumetric expansion of gas in the conduit, with rates of change of the deformation comparable to ground inflation related to pre-burst conduit pressurization. Eruptions involve the ejection of relatively slow and cold bombs and lapilli, and debris is observed to both fall back into the vent after each explosion and to gravitationally accumulate between explosions by rolling down the inner crater flanks to produce the cover itself. Part of this material may also contribute to the formation of a more degassed, crystallized and viscous magma layer at the top of the conduit. Conversely, open-vent explosions erupt with hotter pyroclasts, with higher exit velocity and with minor or no ash phase involved.

  20. Shape-Shifting Plastic

    SciTech Connect

    2015-05-20

    A new plastic developed by ORNL and Washington State University transforms from its original shape through a series of temporary shapes and returns to its initial form. The shape-shifting process is controlled through changes in temperature

  1. A Plastic Menagerie

    ERIC Educational Resources Information Center

    Hadley, Mary Jane

    2010-01-01

    Bobble heads had become quite popular, depicting all sorts of sports figures, animals, and even presidents. In this article, the author describes how her fourth graders made bobble head sculptures out of empty plastic drink bottles. (Contains 1 online resource.)

  2. Recycle plastics into feedstocks

    SciTech Connect

    Kastner, H.; Kaminsky, W.

    1995-05-01

    Thermal cracking of mixed-plastics wastes with a fluidized-bed reactor can be a viable and cost-effective means to meet mandatory recycling laws. Strict worldwide environmental statutes require the hydrocarbon processing industry (HPI) to develop and implement product applications and technologies that reuse post-consumer mixed-plastics waste. Recycling or reuse of plastics waste has a broad definition. Recycling entails more than mechanical regranulation and remelting of polymers for film and molding applications. A European consortium of academia and refiners have investigated if it is possible and profitable to thermally crack plastics into feedstocks for refining and petrochemical applications. Development and demonstration of pyrolysis methods show promising possibilities of converting landfill garbage into valuable feedstocks such as ethylene, propylene, BTX, etc. Fluidized-bed reactor technologies offer HPI operators a possible avenue to meet recycling laws, conserve raw materials and yield a profit. The paper describes thermal cracking for feedstocks and pyrolysis of polyolefins.

  3. Plasticity of amorphous carbon

    NASA Astrophysics Data System (ADS)

    von Lautz, Julian; Moseler, Michael; Pastewka, Lars

    2014-03-01

    We use molecular dynamics simulations to probe the plastic response of representative bulk volumes of amorphous carbon at densities from 2.0 g cm-3 to 3.3 g cm-3 in simple and triaxial shear. After an initial elastic response the samples yield with only little strain hardening or softening. Individual plastic events in this network forming glass are strikingly similar to those observed for bulk metallic glasses: We find that plasticity is carried by fundamental rearrangements of regions of around 100 atoms, the shear transformation zone. In the simple shear geometry, those events coalesce to form a shear-band on longer time scales. During plastic deformation, the material changes its hybridization by transforming sp3 carbon atoms to sp2. We provide evidence that this transformation of the structural state occurs before the material yields, hence weakening the material. This work was supported by the European Commission (Marie-Curie IOF 272619).

  4. Thermodynamic States in Explosion Fields

    SciTech Connect

    Kuhl, A L

    2009-10-16

    Here we investigate the thermodynamic states occurring in explosion fields from the detonation of condensed explosives in air. In typical applications, the pressure of expanded detonation products gases is modeled by a Jones-Wilkins-Lee (JWL) function: P{sub JWL} = f(v,s{sub CJ}); constants in that function are fit to cylinder test data. This function provides a specification of pressure as a function of specific volume, v, along the expansion isentrope (s = constant = s{sub CJ}) starting at the Chapman-Jouguet (CJ) state. However, the JWL function is not a fundamental equation of thermodynamics, and therefore gives an incomplete specification of states. For example, explosions inherently involve shock reflections from surfaces; this changes the entropy of the products, and in such situations the JWL function provides no information on the products states. In addition, most explosives are not oxygen balanced, so if hot detonation products mix with air, they after-burn, releasing the heat of reaction via a turbulent combustion process. This raises the temperature of explosion products cloud to the adiabatic flame temperature ({approx}3,000K). Again, the JWL function provides no information on the combustion products states.

  5. Laser cutting plastic materials

    SciTech Connect

    Van Cleave, R.A.

    1980-08-01

    A 1000-watt CO/sub 2/ laser has been demonstrated as a reliable production machine tool for cutting of plastics, high strength reinforced composites, and other nonmetals. More than 40 different plastics have been laser cut, and the results are tabulated. Applications for laser cutting described include fiberglass-reinforced laminates, Kevlar/epoxy composites, fiberglass-reinforced phenolics, nylon/epoxy laminates, ceramics, and disposable tooling made from acrylic.

  6. The vapor pressures of explosives

    SciTech Connect

    Ewing, Robert G.; Waltman, Melanie J.; Atkinson, David A.; Grate, Jay W.; Hotchkiss, Peter

    2013-01-05

    The vapor pressures of many explosive compounds are extremely low and thus determining accurate values proves difficult. Many researchers, using a variety of methods, have measured and reported the vapor pressures of explosives compounds at single temperatures, or as a function of temperature using vapor pressure equations. There are large variations in reported vapor pressures for many of these compounds, and some errors exist within individual papers. This article provides a review of explosive vapor pressures and describes the methods used to determine them. We have compiled primary vapor pressure relationships traceable to the original citations and include the temperature ranges for which they have been determined. Corrected values are reported as needed and described in the text. In addition, after critically examining the available data, we calculate and tabulate vapor pressures at 25 °C.

  7. Evidence for nearby supernova explosions.

    PubMed

    Benítez, Narciso; Maíz-Apellániz, Jesús; Canelles, Matilde

    2002-02-25

    Supernova (SN) explosions are one of the most energetic---and potentially lethal---phenomena in the Universe. We show that the Scorpius-Centaurus OB association, a group of young stars currently located at approximately 130 pc from the Sun, has generated 20 SN explosions during the last 11 Myr, some of them probably as close as 40 pc to our planet. The deposition on Earth of (60)Fe atoms produced by these explosions can explain the recent measurements of an excess of this isotope in deep ocean crust samples. We propose that approximately 2 Myr ago, one of the SNe exploded close enough to Earth to seriously damage the ozone layer, provoking or contributing to the Pliocene-Pleistocene boundary marine extinction. PMID:11863949

  8. Optimal dynamic detection of explosives

    SciTech Connect

    Moore, David Steven; Mcgrane, Shawn D; Greenfield, Margo T; Scharff, R J; Rabitz, Herschel A; Roslund, J

    2009-01-01

    The detection of explosives is a notoriously difficult problem, especially at stand-off distances, due to their (generally) low vapor pressure, environmental and matrix interferences, and packaging. We are exploring optimal dynamic detection to exploit the best capabilities of recent advances in laser technology and recent discoveries in optimal shaping of laser pulses for control of molecular processes to significantly enhance the standoff detection of explosives. The core of the ODD-Ex technique is the introduction of optimally shaped laser pulses to simultaneously enhance sensitivity of explosives signatures while reducing the influence of noise and the signals from background interferents in the field (increase selectivity). These goals are being addressed by operating in an optimal nonlinear fashion, typically with a single shaped laser pulse inherently containing within it coherently locked control and probe sub-pulses. With sufficient bandwidth, the technique is capable of intrinsically providing orthogonal broad spectral information for data fusion, all from a single optimal pulse.

  9. Explosive evaporation in solar flares

    NASA Technical Reports Server (NTRS)

    Fisher, George H.

    1987-01-01

    This paper develops a simple analytical model for the phenomenon of 'explosive evaporation' driven by nonthermal electron heating in solar flares. The model relates the electron energy flux and spectrum, plus details of the preflare atmosphere, to the time scale for explosive evaporation to occur, the maximum pressure and temperature to be reached, rough estimates for the UV pulse emission flux and duration, and the evolution of the blueshifted component of the soft X-ray lines. An expression is given for the time scale for buildup to maximum pressures and the onset of rapid motion of the explosively evaporating plasma. This evaporation can excite a rapid response of UV line and continuum emission. The emission lines formed in the plasma approach a given emissivity-weighted blueshift speed.

  10. Permeability enhancement using explosive techniques

    SciTech Connect

    Adams, T.F.; Schmidt, S.C.; Carter, W.J.

    1980-01-01

    In situ recovery methods for many of our hydrocarbon and mineral resources depend on the ability to create or enhance permeability in the resource bed to allow uniform and predictable flow. To meet this need, a new branch of geomechanics devoted to computer prediction of explosive rock breakage and permeability enhancement has developed. The computer is used to solve the nonlinear equations of compressible flow, with the explosive behavior and constitutive properties of the medium providing the initial/boundary conditions and material response. Once the resulting computational tool has been verified and calibrated with appropriate large-scale field tests, it can be used to develop and optimize commercially useful explosive techniques for in situ resource recovery.

  11. The Most Powerful Stellar Explosions

    NASA Astrophysics Data System (ADS)

    Chen, Ke-Jung; Heger, Alexander; Woosley, Stan; Almgren, Ann; Zhang, Weiqun

    2013-04-01

    We present the results from our 3D simulations of thermonuclear supernovae from the stars with initial masses above 80 solar masses by using CASTRO, a new, massively parallel, multidimensional Eulerian, adaptive mesh refinement (AMR), radiation-hydrodynamics code. We first use Kepler, a one-dimensional spherically-symmetric Lagrangian code to model the possible explosions beyond hypernovae. These extreme explosions include two types of electron/positron production instability supernovae and one type of general relativity instability supernovae. The resulting 1D presupernova profiles are mapped onto 3D grids of CASTRO as initial conditions. We simulate the explosion in 3D and resolve the emergent fluid instabilities. In this talk, we will discuss the energetics, nucleosynthesis, and possible observational signatures of these supernovae.

  12. 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.

  13. 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.

  14. Prompt Reaction of Aluminum in Detonating Explosives

    NASA Astrophysics Data System (ADS)

    Sandusky, Harold

    2005-07-01

    The potential of aluminum reaction to boost detonation energy has been studied for decades, most recently spurred by the availability of nanometer-sized particles. A review of the literature provides perspective for a recent study with the small-scale shock reactivity test. In this test, <1/2-g samples in confinement are shock loaded on one end, and the output at the other end dents a soft witness block. One test series had 0.3 g of HMX mixed with various forms of aluminum added in amounts of up to 25% of the total sample mass, with the deepest dent for H-5 aluminum occuring at 15%. Test results on ammonium perchlorate mixed with H-5 aluminum were consistent with the peak in detonation velocity reported in Combustion and Flame by Price in 1973 on similar mixtures. One outcome of this study is a new interpretation for the participation of aluminum in large scale gap tests on plastic-bonded explosives, which was discussed by Bernecker at this meeting in 1987.

  15. The Need for Plastics Education.

    ERIC Educational Resources Information Center

    Society of Plastics Engineers, Inc., Stamford, CT.

    In view of a lack of trained personnel in the industry, the Plastics Education Foundation proposes that educators (1) add more plastics programs, (2) establish plastics engineering degrees at appropriate 4-year institutions, (3) add plastics processing technology to current engineering curricula, and (4) interest younger students in courses and/or…

  16. The Need for Plastics Education.

    ERIC Educational Resources Information Center

    Society of Plastics Engineers, Inc., Stamford, CT.

    In view of a lack of trained personnel in the industry, the Plastics Education Foundation proposes that educators (1) add more plastics programs, (2) establish plastics engineering degrees at appropriate 4-year institutions, (3) add plastics processing technology to current engineering curricula, and (4) interest younger students in courses and/or

  17. Lightning Protection for Explosive Facilities

    SciTech Connect

    Ong, M

    2001-12-01

    Lawrence Livermore National Laboratory funds construction of lightning protection systems to protect explosive processing and storage facilities. This paper provides an intuitive understanding of the lighting risks and types of lightning protection available. Managers can use this information to decide if limited funds should be spent constructing a lightning protection system for their own facilities. This paper answers the following questions: (1) Why do you need lightning protection systems? (2) How do lightning protection systems work? and (3) Why are there no documented cases of lightning problems at existing explosive facilities?

  18. Intravesical explosion during transurethral electrosurgery.

    PubMed

    Georgios, Kallinikas; Evangelos, Boulinakis; Helai, Habib; Ioannis, Gerzelis

    2015-05-01

    Intravesical explosion is a very rare complication of transurethral resection of prostate and transurethral resection of bladder tumour operations. In vitro studies have shown that the gases produced during the procedure could result in a blast once they are mixed with air from the atmosphere. A 79-year-old male experienced an explosion in his bladder while undergoing a transurethral resection of bladder tumour. The case is presented as well as the way that it was treated as an emergency. Precautions of such events are finally suggested. PMID:25680867

  19. Explosive coalescence of magnetic islands

    NASA Technical Reports Server (NTRS)

    Tajima, T.; Sakai, J.-I.

    1986-01-01

    Simulation results from both the EM collisionless particle code and the MHD particle code reveal an explosive reconnection process associated with nonlinear evolution of the coalescence instability. The explosive coalescence is a self-similar process of magnetic collapse, and ensuing amplitude oscillations in the magnetic and electrostatic energies and temperatures are modeled by an equation of motion for the scale factor in the Sagdeev potential. This phenomenon may explain the rapid energy release of a certain class of solar flares during their impulsive phase.

  20. HERMES: A Model to Describe Deformation, Burning, Explosion, and Detonation

    SciTech Connect

    Reaugh, J E

    2011-11-22

    HERMES (High Explosive Response to MEchanical Stimulus) was developed to fill the need for a model to describe an explosive response of the type described as BVR (Burn to Violent Response) or HEVR (High Explosive Violent Response). Characteristically this response leaves a substantial amount of explosive unconsumed, the time to reaction is long, and the peak pressure developed is low. In contrast, detonations characteristically consume all explosive present, the time to reaction is short, and peak pressures are high. However, most of the previous models to describe explosive response were models for detonation. The earliest models to describe the response of explosives to mechanical stimulus in computer simulations were applied to intentional detonation (performance) of nearly ideal explosives. In this case, an ideal explosive is one with a vanishingly small reaction zone. A detonation is supersonic with respect to the undetonated explosive (reactant). The reactant cannot respond to the pressure of the detonation before the detonation front arrives, so the precise compressibility of the reactant does not matter. Further, the mesh sizes that were practical for the computer resources then available were large with respect to the reaction zone. As a result, methods then used to model detonations, known as {beta}-burn or program burn, were not intended to resolve the structure of the reaction zone. Instead, these methods spread the detonation front over a few finite-difference zones, in the same spirit that artificial viscosity is used to spread the shock front in inert materials over a few finite-difference zones. These methods are still widely used when the structure of the reaction zone and the build-up to detonation are unimportant. Later detonation models resolved the reaction zone. These models were applied both to performance, particularly as it is affected by the size of the charge, and to situations in which the stimulus was less than that needed for reliable performance, whether as a result of accident, hazard, or a fault in the detonation train. These models describe the build-up of detonation from a shock stimulus. They are generally consistent with the mesoscale picture of ignition at many small defects in the plane of the shock front and the growth of the resulting hot-spots, leading to detonation in heterogeneous explosives such as plastic-bonded explosives (PBX). The models included terms for ignition, and also for the growth of reaction as tracked by the local mass fraction of product gas, {lambda}. The growth of reaction in such models incorporates a form factor that describes the change of surface area per unit volume (specific surface area) as the reaction progresses. For unimolecular crystalline-based explosives, the form factor is consistent with the mesoscale picture of a galaxy of hot spots burning outward and eventually interacting with each other. For composite explosives and propellants, where the fuel and oxidizer are segregated, the diffusion flame at the fuel-oxidizer interface can be interpreted with a different form factor that corresponds to grains burning inward from their surfaces. The form factor influences the energy release rate, and the amount of energy released in the reaction zone. Since the 19th century, gun and cannon propellants have used perforated geometric shapes that produce an increasing surface area as the propellant burns. This helps maintain the pressure as burning continues while the projectile travels down the barrel, which thereby increases the volume of the hot gas. Interior ballistics calculations use a geometric form factor to describe the changing surface area precisely. As a result, with a suitably modified form factor, detonation models can represent burning and explosion in damaged and broken reactant. The disadvantage of such models in application to accidents is that the ignition term does not distinguish between a value of pressure that results from a shock, and the same pressure that results from a more gradual increase. This disagrees with experiments, where explosives were subjected to a gradual rise in pressure and did not exhibit reaction. More recent models do distinguish between slow pressure rises and shocks, and have had some success in the describing the response of explosives to single and multiple shocks, and the increase of shock sensitivity with porosity, at least over a limited range. The original formulation is appropriate for sustained shocks, but further work is ongoing to describe the response to short pulses. The HERMES model combines features from these prior models. It describes burning and explosion in damaged reactant, and also will develop a detonation if the gradual rise in pressure from burning steepens into a strong-enough shock. The shock strength needed for detonation in a fixed run distance decreases with increasing porosity.

  1. Trace Detection of RDX, HMX and PETN Explosives Using a Fluorescence Spot Sensor

    PubMed Central

    Wang, Chen; Huang, Helin; Bunes, Benjamin R.; Wu, Na; Xu, Miao; Yang, Xiaomei; Yu, Li; Zang, Ling

    2016-01-01

    1,3,5-trinitroperhydro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and pentaerythritol tetranitrate (PETN), the major components in plastic explosives, pose a significant threat to public safety. A quick, sensitive, and low-cost detection method for these non-volatile explosives is eagerly demanded. Here we present a fluo-spot approach, which can be employed for in situ detection of trace amount of explosives. The sensor molecule is a charge-transfer fluorophore, DCM, which is strongly fluorescent in its pristine state, but non-fluorescent after the quick reaction with NO2· (or NO2+) generated from the UV photolysis of RDX, HMX (or PETN). When fabricated within silica gel TLC plate, the fluo-spot sensor features high sensitivity owing to the large surface area and porous structure of the substrate. The sensor reaction mechanism was verified by various experimental characterizations, including chromatography, UV-Vis absorption and fluorescence spectroscopy, MS and 1H NMR spectrometry. The fluo-spot also demonstrated high selectivity towards RDX, HMX and PETN, as no significant fluorescence quenching was observed for other chemical compounds including common nitro-aromatic explosives and inorganic oxidative compounds. The DCM sensor can also be used as an economical spray kit to directly spot the explosives by naked eyes, implying great potential for quick, low-cost trace explosives detection. PMID:27146290

  2. Trace Detection of RDX, HMX and PETN Explosives Using a Fluorescence Spot Sensor.

    PubMed

    Wang, Chen; Huang, Helin; Bunes, Benjamin R; Wu, Na; Xu, Miao; Yang, Xiaomei; Yu, Li; Zang, Ling

    2016-01-01

    1,3,5-trinitroperhydro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and pentaerythritol tetranitrate (PETN), the major components in plastic explosives, pose a significant threat to public safety. A quick, sensitive, and low-cost detection method for these non-volatile explosives is eagerly demanded. Here we present a fluo-spot approach, which can be employed for in situ detection of trace amount of explosives. The sensor molecule is a charge-transfer fluorophore, DCM, which is strongly fluorescent in its pristine state, but non-fluorescent after the quick reaction with NO2· (or NO2(+)) generated from the UV photolysis of RDX, HMX (or PETN). When fabricated within silica gel TLC plate, the fluo-spot sensor features high sensitivity owing to the large surface area and porous structure of the substrate. The sensor reaction mechanism was verified by various experimental characterizations, including chromatography, UV-Vis absorption and fluorescence spectroscopy, MS and (1)H NMR spectrometry. The fluo-spot also demonstrated high selectivity towards RDX, HMX and PETN, as no significant fluorescence quenching was observed for other chemical compounds including common nitro-aromatic explosives and inorganic oxidative compounds. The DCM sensor can also be used as an economical spray kit to directly spot the explosives by naked eyes, implying great potential for quick, low-cost trace explosives detection. PMID:27146290

  3. Numerical simulation study on thermal response of PBX explosive by low velocity impact

    NASA Astrophysics Data System (ADS)

    Lou, Jianfeng; Zhou, Tingting; Zhang, Yangeng; Zhang, Xiaoli

    2015-06-01

    It is a great threat for both bare dynamite and shell charge when subjected to low velocity impact involved in traffic accidents or charge piece drops. The impact sensitivity is an important index in evaluating the safety and performance of explosives. The Steven Test is an effective tool to evaluate the relative sensitivity of various explosives. In 1993, Chidester et al. preliminarily designed the Steven Test, and then applied it to delay detonation (XDT) phenomenon study. Subsequently, a series of low velocity impact Steven Tests on HMX based explosives were carried out by S K Chidester, D J Idar, R J Scammon, S Wortley et al. In this paper, we built the numerical simulation method involving mechanical, thermo and chemical properties of Steven Test based on the thermo-mechanical coupled material model. In the model, the stress-strain relationship is described by dynamic plasticity model, the thermal effect of the explosive induced by impact is depicted by isotropic thermal material model, the chemical reaction of explosives is described by Arrhenius reaction rate law, and the effects of heating and melting on mechanical properties and thermal properties of materials are also taken into account. Specific to the standard Steven Test, the thermal and mechanical response rules of PBX9501 at different impact velocities were numerical analyzed, and the threshold velocity of explosive initiation was obtained. In addition, the effect of confine condition of test device to the threshold velocity was explored.

  4. Apparatus for monitoring linear explosive performance

    NASA Technical Reports Server (NTRS)

    Bement, L. J.

    1974-01-01

    Techniques provide performance monitoring standard for acceptance, lot qualification, and comparison testing of devices. Exhibit high degree of simplicity, accuracy, and reproducibility. Apparatus simultaneously measures explosive pressure stimulus energy, explosive cutting, or rupturing, ability, and detonation propagation rate.

  5. 46 CFR 188.10-25 - Explosive.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... mixture, the primary purpose of which is to function by explosion; i.e., with substantially instantaneous release of gas and heat. Explosives are discussed in more detail in 49 CFR parts 171-179....

  6. 46 CFR 188.10-25 - Explosive.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... mixture, the primary purpose of which is to function by explosion; i.e., with substantially instantaneous release of gas and heat. Explosives are discussed in more detail in 49 CFR parts 171-179....

  7. 46 CFR 188.10-25 - Explosive.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... mixture, the primary purpose of which is to function by explosion; i.e., with substantially instantaneous release of gas and heat. Explosives are discussed in more detail in 49 CFR parts 171-179....

  8. Sandia Explosive Inventory and Information System

    SciTech Connect

    Clements, D.A.

    1994-08-01

    The Explosive Inventory and Information System (EIS) is being developed and implemented by Sandia National Laboratories (SNL) to incorporate a cradle to grave structure for all explosives and explosive containing devices and assemblies at SNL from acquisition through use, storage, reapplication, transfer or disposal. The system does more than track all material inventories. It provides information on material composition, characteristics, shipping requirements; life cycle cost information, plan of use; and duration of ownership. The system also provides for following the processes of explosive development; storage review; justification for retention; Resource, Recovery and Disposition Account (RRDA); disassembly and assembly; and job description, hazard analysis and training requirements for all locations and employees involved with explosive operations. In addition, other information systems will be provided through the system such as the Department of Energy (DOE) and SNL Explosive Safety manuals, the Navy`s Department of Defense (DoD) Explosive information system, and the Lawrence Livermore National Laboratories (LLNL) Handbook of Explosives.

  9. The plasticity of clays

    USGS Publications Warehouse

    Group, F.F.

    1905-01-01

    (1) Sand injures plasticity little at first because the grains are suspended in a plastic mass. It is only when grains are abundant enough to come in contact with their neighbors, that the effect becomes serious, and then both strength and amount of possible flow are injured. (2) Certain rare organic colloids increase the plasticity by rendering the water viscous. (3) Fineness also tends to increase plasticity. (4) Plane surfaces (plates) increase the amount of possible flow. They also give a chance for lubrication by thinner films, thus increasing the friction of film, and the strength of the whole mass. The action of plates is thus twofold ; but fineness may be carried to such an extent as to break up plate-like grains into angular fragments. The beneficial effects of plates are also decreased by the fact that each is so closely surrounded by others in the mass. (5) Molecular attraction is twofold in increasing plasticity. As the attraction increases, the coherence and strength of the mass increase, and the amount of possible deformation before crumbling also increases. Fineness increases this action by requiring more water. Colloids and crystalloids in solution may also increase the attraction. It is thus seen to be more active than any other single factor.

  10. Some features of the fabrication of multilayer fiber composites by explosive welding

    NASA Technical Reports Server (NTRS)

    Kotov, V. A.; Mikhaylov, A. N.; Cabelka, D.

    1985-01-01

    The fabrication of multilayer fiber composites by explosive welding is characterized by intense plastic deformation of the matrix material as it fills the spaces between fibers and by high velocity of the collision between matrix layers due to acceleration in the channels between fibers. The plastic deformation of the matrix layers and fiber-matrix friction provide mechanical and thermal activation of the contact surfaces, which contributes to the formation of a bond. An important feature of the process is that the fiber-matrix adhesion strength can be varied over a wide range by varying the parameters of impulsive loading.

  11. Numerical Simulations of Thermobaric Explosions

    SciTech Connect

    Kuhl, A L; Bell, J B; Beckner, V E; Khasainov, B

    2007-05-04

    A Model of the energy evolution in thermobaric explosions is presented. It is based on the two-phase formulation: conservation laws for the gas and particle phases along with inter-phase interaction terms. It incorporates a Combustion Model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gas dynamic fields. The Model takes into account both the afterburning of the detonation products of the booster with air, and the combustion of the fuel (Al or TNT detonation products) with air. Numerical simulations were performed for 1.5-g thermobaric explosions in five different chambers (volumes ranging from 6.6 to 40 liters and length-to-diameter ratios from 1 to 12.5). Computed pressure waveforms were very similar to measured waveforms in all cases - thereby proving that the Model correctly predicts the energy evolution in such explosions. The computed global fuel consumption {mu}(t) behaved as an exponential life function. Its derivative {dot {mu}}(t) represents the global rate of fuel consumption. It depends on the rate of turbulent mixing which controls the rate of energy release in thermobaric explosions.

  12. Turbulent Combustion in SDF Explosions

    SciTech Connect

    Kuhl, A L; Bell, J B; Beckner, V E

    2009-11-12

    A heterogeneous continuum model is proposed to describe the dispersion and combustion of an aluminum particle cloud in an explosion. It combines the gas-dynamic conservation laws for the gas phase with a continuum model for the dispersed phase, as formulated by Nigmatulin. Inter-phase mass, momentum and energy exchange are prescribed by phenomenological models. It incorporates a combustion model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gasdynamic fields, along with a model for mass transfer from the particle phase to the gas. The model takes into account both the afterburning of the detonation products of the C-4 booster with air, and the combustion of the Al particles with air. The model equations were integrated by high-order Godunov schemes for both the gas and particle phases. Numerical simulations of the explosion fields from 1.5-g Shock-Dispersed-Fuel (SDF) charge in a 6.6 liter calorimeter were used to validate the combustion model. Then the model was applied to 10-kg Al-SDF explosions in a an unconfined height-of-burst explosion. Computed pressure histories are compared with measured waveforms. Differences are caused by physical-chemical kinetic effects of particle combustion which induce ignition delays in the initial reactive blast wave and quenching of reactions at late times. Current simulations give initial insights into such modeling issues.

  13. Anomalous electrodynamic explosions in liquids

    SciTech Connect

    Aspden, H.

    1986-06-01

    The recently reported Graneau experiments on electrodynamic explosions in liquids, which reveal anomalous longitudinal electrodynamic forces of the order of 10/sup 4/ times greater than expected, verify the need for a term in the law of electrodynamics that corresponds to the ion/electron mass ratio. This confirms an earlier theoretical interpretation of the anomalous cathode reaction forces found in the vacuum arc.

  14. Lead-free primary explosives

    DOEpatents

    Huynh, My Hang V.

    2010-06-22

    Lead-free primary explosives of the formula (cat).sub.Y[M.sup.II(T).sub.X(H.sub.2O).sub.6-X].sub.Z, where T is 5-nitrotetrazolate, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

  15. Episodic explosions in interstellar ices

    NASA Astrophysics Data System (ADS)

    Rawlings, J. M. C.; Williams, D. A.; Viti, S.; Cecchi-Pestellini, C.; Duley, W. W.

    2013-03-01

    We present a model for the formation of large organic molecules in dark clouds. The molecules are produced in the high-density gas phase that exists immediately after ice mantles are explosively sublimated. The explosions are initiated by the catastrophic recombination of trapped atomic hydrogen. We propose that, in molecular clouds, the processes of freeze-out on to ice mantles, accumulation of radicals, explosion and then rapid (three-body) gas-phase chemistry occurs in a cyclic fashion. This can lead to a cumulative molecular enrichment of the interstellar medium. A model of the time-dependent chemistries, based on this hypothesis, shows that significant abundances of large molecular species can be formed, although the complexity of the species is limited by the short expansion time-scale in the gas, immediately following mantle explosion. We find that this mechanism may be an important source of smaller organic species, such as methanol and formaldehyde, as well as precursors to bio-molecule formation. Most significantly, we predict the gas-phase presence of these larger molecular species in quiescent molecular clouds and not just dynamically active regions, such as hot cores. As such the mechanism that we propose complements alternative methods of large molecule formation, such as those that invoke solid-state chemistry within activated ice mantles.

  16. Soft container for explosive nuts

    NASA Technical Reports Server (NTRS)

    Glenn, D. C.; Drummond, W. E.; Miller, G.

    1981-01-01

    Flexible fabric fits over variety of assembly shapes to contain debris produced by detonations or safety tests. Bag material is woven multifilament polyamide or aramid. Belt loops hold bag to clamp. Ring supports explosive nut structure and detonator wires, and after nut is mounted, bag and clamp are slipped over ring and fastened.

  17. Explosion welding and cutting in aerospace engineering

    NASA Astrophysics Data System (ADS)

    Volgin, L. A.; Koroteev, A. Ia.; Malakovich, A. P.; Petushkov, V. G.; Sitalo, V. G.; Novikov, V. K.

    The paper presents the results of works of the E.O. Paton Electric Welding Institute and other Soviet organizations on the development of technology for explosion-welding of multilayer transition pieces and pipes used in the manufacture of aerospace products. Equipment and accessories used for this technology are described; in particular, a powerful explosion chamber of a tubular structure for up to 200 kg of explosives is presented. Information is also given about linear explosion separation devices.

  18. Explosives for Lunar Seismic Profiling Experiment (LSPE)

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Explosive charges of various sizes were investigated for use in lunar seismic studies. Program logistics, and the specifications for procurement of bulk explosives are described. The differential analysis, thermal properties, and detonation velocity measurements on HNS/Teflon 7C 90/10 are reported along with the field tests of the hardware. It is concluded that nearly all large explosive charges crack after fabrication, from aging or thermal shock. The cracks do not affect the safety, or reliability of the explosives.

  19. 76 FR 64974 - Commerce in Explosives; List of Explosive Materials (2011R-18T)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-19

    ... Explosive Materials dated November 17, 2010 (Docket No. ATF 42N, 75 FR 70291). Notice of List of Explosive... propellant. Aluminum ophorite explosive. Amatex. Amatol. Ammonal. Ammonium nitrate explosive mixtures (cap... composite propellant (APCP)). Ammonium picrate . Ammonium salt lattice with isomorphously...

  20. Acoustic nonlinearity in plastics

    NASA Astrophysics Data System (ADS)

    Nagy, Peter B.; Adler, Laszlo

    A quasi-static acoustoelastic technique is employed to measure the second-order acoustoelastic parameter in plastic beams under bending deformation. The effect of material composition, temperature, and fatigue on the nonlinear behavior of plastics is studied, and the sensitivity of different linear and nonlinear parameters to the degradation of material strength during long-term fatigue loads is examined. Plastics are found to be highly nonlinear, and the second-order acoustoelastic parameter is argued to be much more sensitive to the degradation of strength due to long-term fatigue loads than linear parameters such as the 'quasi-static' Young's modulus, sound velocity, and attenuation. These results are in agreement with earlier predictions that nonlinear ultrasonic measurement technique and analysis are essential to predict failure mechanisms in adhesively bonded structures.

  1. Consumer hazards of plastics.

    PubMed Central

    Wiberg, G S

    1976-01-01

    The modern consumer is exposed to a wide variety of plastic and rubber products in his day to day life: at home, work, school, shopping, recreation and play, and transport. A large variety of toxic sequellae have resulted from untoward exposures by many different routes: oral, dermal, inhalation, and parenteral. Toxic change may result from the plastic itself, migration of unbound components and additives, chemical decomposition or toxic pyrolysis products. The type of damage may involve acute poisoning, chronic organ damage, reproductive disorders, and carcinogenic, mutagenic and teratogenic episodes. Typical examples for all routes are cited along with the activites of Canadian regulatory agencies to reduce both the incidence and severity of plastic-induced disease. PMID:1026409

  2. Plastic condom developed.

    PubMed

    1992-01-01

    A prototype plastic condom that is expected to be at least as strong as latex, less likely to fail, and more comfortable to use has been designed by researchers at North Carolina-based Family Health International (FHI). The National Institutes of Health has granted the nonprofit medical research organization $1.3 million to conduct tests that will include clinical trials involving volunteer couples to examine the condom/s safety, efficacy in preventing pregnancy, and acceptability among users. Researchers hope the tests, expected to take about 4 years, will show that the plastic condom can be stored for years without weakening, whereas latex loses strength with time. In addition, FHI claims the plastic condom can be used with any kind of lubricant, while Latex is limited to water-based or silicone lubricants. Latex condoms lose up to 90% of their strength when used with oil-based lubricants such as hand lotion, according to studies. PMID:12285831

  3. Involvement in plastic pipe

    SciTech Connect

    Buczala, G.S.; Walker, R.P.

    1983-08-01

    Vested with the responsibility of writing plastic pipe standards, ASTM's Subcommittee D20.17 on Thermoplastic Pipe and Fittings (later reorganized as a full committee, F-17) compiled many of the test methods and standards now accepted by local, state, and federal agencies. One of the most comprehensive piping specifications under F-17's jurisdiction covers gas-pressure piping materials including cellusone acetate butyrate, acrylonitrile butadiene styrene, high- and normal-impact polyvinyl chloride, a variety of polyethylenes, and polybutylene. All of these materials have been used for gas distribution service, some dating back to 1942. As of 1982, figures show that 200,000 miles of all sizes of plastic gas pipe for both gas services and mains have been installed, representing 16.5% of the total gas distribution system in the US. From a handful of early pioneers, the number of utilities using plastic pipe now stands at 933.

  4. Transuranic drum hydrogen explosion tests

    SciTech Connect

    Dykes, K.L.; Meyer, M.L.

    1991-06-01

    Radiolysis of transuranic (TRU) waste can produce flammable ({gt}4%) mixtures of hydrogen gas in 55 gallon vented waste storage drums. Explosion testing was conducted at the E. I. duPont Explosion Hazards Laboratory to determine the minimum concentration at which a drum lid removal occurs. A secondary objective was to investigate the maximum pressure and rate of pressure rise as a function of hydrogen concentration. Prior to beginning any drum explosion tests, small-scale pressure vessel tests and drum mixing tests were completed. The pressure vessel tests established a relationship between hydrogen concentration and the maximum pressure and pressure rise. These small-scale tests were used to establish the concentration range over which a drum lid removal might occur. Mixing tests were also conducted to determine the equilibration times for two different hydrogen-air mixtures in a TRU drum. Nine successful drum explosion tests were conducted over a hydrogen concentration range of 13--36% (v/v), test results suggest total integrity failure via drum lid removal will not occur below 15% (v/v). Controlled small-scale pressure vessel tests were conducted over a range of 5--50% (v/v) to determine the pressure and pressure rise as a function of hydrogen concentration. No similar relationship could be established for the drum explosion tests due to the variability in drum lid sealing and retaining ring closure. Mixing tests conducted at 5% and 25% (v/v) indicate adding pure hydrogen to the middle of a drum causes some initial stratification along the drum length, but the air and hydrogen become well-mixed after 50 minutes. 4 refs., 11 figs., 2 tabs.

  5. 46 CFR 153.921 - Explosives.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Explosives. 153.921 Section 153.921 Shipping COAST GUARD....921 Explosives. No person may load, off-load, or carry a cargo listed in this part on board a vessel that carries explosives unless he has the prior written permission of the Commandant (CG-ENG)....

  6. 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.

  7. 33 CFR 401.67 - Explosive vessels.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Explosive vessels. 401.67 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Dangerous Cargo § 401.67 Explosive vessels. A vessel carrying explosives, either Government or commercial, as defined in the Dangerous Cargo Act of the...

  8. 33 CFR 401.67 - Explosive vessels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Explosive vessels. 401.67 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Dangerous Cargo § 401.67 Explosive vessels. A vessel carrying explosives, either Government or commercial, as defined in the Dangerous Cargo Act of the...

  9. 14 CFR 420.63 - Explosive siting.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Explosive siting. 420.63 Section 420.63... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Responsibilities of a Licensee § 420.63 Explosive... the configuration of the launch site is in accordance with an explosive site plan, and that...

  10. 46 CFR 153.921 - Explosives.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Explosives. 153.921 Section 153.921 Shipping COAST GUARD....921 Explosives. No person may load, off-load, or carry a cargo listed in this part on board a vessel that carries explosives unless he has the prior written permission of the Commandant (CG-ENG)....

  11. 33 CFR 401.67 - Explosive vessels.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Explosive vessels. 401.67 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Dangerous Cargo § 401.67 Explosive vessels. A vessel carrying explosives, either Government or commercial, as defined in the Dangerous Cargo Act of the...

  12. 46 CFR 153.921 - Explosives.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Explosives. 153.921 Section 153.921 Shipping COAST GUARD....921 Explosives. No person may load, off-load, or carry a cargo listed in this part on board a vessel that carries explosives unless he has the prior written permission of the Commandant (CG-ENG)....

  13. 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.

  14. 14 CFR 420.63 - Explosive siting.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Explosive siting. 420.63 Section 420.63... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Responsibilities of a Licensee § 420.63 Explosive... the configuration of the launch site is in accordance with an explosive site plan, and that...

  15. 46 CFR 153.921 - Explosives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Explosives. 153.921 Section 153.921 Shipping COAST GUARD....921 Explosives. No person may load, off-load, or carry a cargo listed in this part on board a vessel that carries explosives unless he has the prior written permission of the Commandant (CG-522)....

  16. 46 CFR 153.921 - Explosives.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Explosives. 153.921 Section 153.921 Shipping COAST GUARD....921 Explosives. No person may load, off-load, or carry a cargo listed in this part on board a vessel that carries explosives unless he has the prior written permission of the Commandant (CG-522)....

  17. 46 CFR 188.10-25 - Explosive.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... release of gas and heat. Explosives are discussed in more detail in 49 CFR parts 171-179. ... 46 Shipping 7 2011-10-01 2011-10-01 false Explosive. 188.10-25 Section 188.10-25 Shipping COAST... Definition of Terms Used in This Subchapter § 188.10-25 Explosive. This term means a chemical compound...

  18. 46 CFR 188.10-25 - Explosive.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... release of gas and heat. Explosives are discussed in more detail in 49 CFR parts 171-179. ... 46 Shipping 7 2010-10-01 2010-10-01 false Explosive. 188.10-25 Section 188.10-25 Shipping COAST... Definition of Terms Used in This Subchapter § 188.10-25 Explosive. This term means a chemical compound...

  19. 14 CFR 420.63 - Explosive siting.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Explosive siting. 420.63 Section 420.63... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Responsibilities of a Licensee § 420.63 Explosive... the configuration of the launch site is in accordance with an explosive site plan, and that...

  20. 33 CFR 401.67 - Explosive vessels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Explosive vessels. 401.67 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Dangerous Cargo § 401.67 Explosive vessels. A vessel carrying explosives, either Government or commercial, as defined in the Dangerous Cargo Act of the...

  1. 33 CFR 401.67 - Explosive vessels.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Explosive vessels. 401.67 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Dangerous Cargo § 401.67 Explosive vessels. A vessel carrying explosives, either Government or commercial, as defined in the Dangerous Cargo Act of the...

  2. Plastic complementary microelectromechanical switches

    NASA Astrophysics Data System (ADS)

    Yokota, Tomoyuki; Nakano, Shintaro; Sekitani, Tsuyoshi; Someya, Takao

    2008-07-01

    We have fabricated plastic complementary microelectromechanical switches by using ink-jet printing technologies. Two vertically stacked regular plastic microelectromechanical switches that are complementary to each other realize the function of an inverter. While rectangular voltage waveforms were periodically applied to the control electrodes in the air, the delay times and durability were examined systematically. The frequency response was 50 Hz for an operation voltage of 60 V. When the number of periodic cycles exceeded 106, the changes in the on resistance of the top and bottom switches were 9% and 43%, respectively.

  3. Explosives detection through fast-neutron time-of-flight attenuation measurements

    NASA Astrophysics Data System (ADS)

    Overley, J. C.; Chmelik, M. S.; Rasmussen, R. J.; Schofield, R. M. S.; Lefevre, H. W.

    1995-05-01

    Computer simulations have been used to devise an algorithm for detection of explosives in luggage which is based upon measured projected number densities of H, C, N, and O. Other elements are lumped together as projection X. Dependence on luggage-thickness is reduced by normalizing the projection for each element by the total. Normalization constrains projections to a 4-dimensional space. Distributions of nonexplosive ( N) and explosive ( E) situations are generated by sorting results of simulations into bins in that 4-space. A detection matrix element, given by the ratio {E}/{(N + E)} for each bin, is addressed by a measurement. For a realistic distribution of the numbers and types of luggage materials, the plastic explosive RDX, at 10% of suitcase thickness, can be detected in a single pixel with 85% reliability and a false alarm rate of 3%.

  4. Desorption electrospray ionization of explosives on surfaces: sensitivity and selectivity enhancement by reactive desorption electrospray ionization.

    PubMed

    Cotte-Rodríguez, Ismael; Takáts, Zoltán; Talaty, Nari; Chen, Huanwen; Cooks, R Graham

    2005-11-01

    Desorption electrospray ionization (DESI), an ambient mass spectrometry technique, is used for trace detection of the explosives trinitrohexahydro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), 2,4,6-trinitrotoluene (TNT), Pentaerythritol tetranitrate (PETN), and their plastic compositions (Composition C-4, Semtex-H, Detasheet) directly from a wide variety of surfaces (metal, plastic, paper, polymer) without sample preparation or pretreatment. Analysis of the explosives is performed under ambient conditions from virtually any surface in very short times (<5 s) including confirmatory tandem mass spectrometry (MS/MS) experiments, while retaining the sensitivity and specificity that mass spectrometry offers. Increased selectivity is obtained both by MS/MS and by performing additional experiments in which additives are included in the spray solvent. These reactive DESI experiments (reactions accompanying desorption) produce such ions as the chloride and trifluoroacetate adducts of RDX and HMX or the Meisenheimer complex of TNT. Desorption atmospheric pressure chemical ionization, a variant of DESI that uses gas-phase ions generated by atmospheric pressure corona discharges of toluene or other organic compounds, provides evidence for a heterogeneous-phase (gaseous ion/absorbed analyte) charge-transfer mechanism of DESI ionization in the case of explosives. Plastic explosives on surfaces were analyzed directly as fingerprints, without sample preparation, to test DESI as a possible method for in situ detection of explosives-contaminated surfaces. DESI also allowed detection of explosives in complex matrixes, including lubricants, household cleaners, vinegar, and diesel fuel. Absolute limits of detection for the neat explosives were subnanogram in all cases and subpicogram in the case of TNT. The DESI response was linear over 3 orders of magnitude for TNT. Quantification of RDX on paper gave a precision (RSD) of 2.3%. Pure water could be used as the spray solution for DESI, and it showed ionization efficiencies for RDX in the negative ion mode similar to that given by methanol/water. DESI represents a simple and rapid way to detect explosives in situ with high sensitivity and specificity and is especially useful when they are present in complex mixtures or in trace amounts on ordinary environmental surfaces. PMID:16255571

  5. Fast and sensitive recognition of various explosive compounds using Raman spectroscopy and principal component analysis

    NASA Astrophysics Data System (ADS)

    Hwang, Joonki; Park, Aaron; Chung, Jin Hyuk; Choi, Namhyun; Park, Jun-Qyu; Cho, Soo Gyeong; Baek, Sung-June; Choo, Jaebum

    2013-06-01

    Recently, the development of methods for the identification of explosive materials that are faster, more sensitive, easier to use, and more cost-effective has become a very important issue for homeland security and counter-terrorism applications. However, limited applicability of several analytical methods such as, the incapability of detecting explosives in a sealed container, the limited portability of instruments, and false alarms due to the inherent lack of selectivity, have motivated the increased interest in the application of Raman spectroscopy for the rapid detection and identification of explosive materials. Raman spectroscopy has received a growing interest due to its stand-off capacity, which allows samples to be analyzed at distance from the instrument. In addition, Raman spectroscopy has the capability to detect explosives in sealed containers such as glass or plastic bottles. We report a rapid and sensitive recognition technique for explosive compounds using Raman spectroscopy and principal component analysis (PCA). Seven hundreds of Raman spectra (50 measurements per sample) for 14 selected explosives were collected, and were pretreated with noise suppression and baseline elimination methods. PCA, a well-known multivariate statistical method, was applied for the proper evaluation, feature extraction, and identification of measured spectra. Here, a broad wavenumber range (200- 3500 cm-1) on the collected spectra set was used for the classification of the explosive samples into separate classes. It was found that three principal components achieved 99.3 % classification rates in the sample set. The results show that Raman spectroscopy in combination with PCA is well suited for the identification and differentiation of explosives in the field.

  6. 27 CFR 555.32 - Special explosive devices.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Special explosive devices..., AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.32 Special explosive devices. The Director may exempt certain explosive...

  7. 27 CFR 555.205 - Movement of explosive materials.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Movement of explosive..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage § 555.205 Movement of explosive materials. All explosive materials must be kept in locked magazines meeting...

  8. 27 CFR 555.32 - Special explosive devices.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Special explosive devices..., AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.32 Special explosive devices. The Director may exempt certain explosive...

  9. 27 CFR 555.32 - Special explosive devices.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Special explosive devices..., AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.32 Special explosive devices. The Director may exempt certain explosive...

  10. 27 CFR 555.205 - Movement of explosive materials.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Movement of explosive..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage § 555.205 Movement of explosive materials. All explosive materials must be kept in locked magazines meeting...

  11. 27 CFR 555.205 - Movement of explosive materials.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Movement of explosive..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage § 555.205 Movement of explosive materials. All explosive materials must be kept in locked magazines meeting...

  12. 27 CFR 555.32 - Special explosive devices.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Special explosive devices..., AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.32 Special explosive devices. The Director may exempt certain explosive...

  13. 27 CFR 555.32 - Special explosive devices.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Special explosive devices..., AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.32 Special explosive devices. The Director may exempt certain explosive...

  14. 27 CFR 555.205 - Movement of explosive materials.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Movement of explosive..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage § 555.205 Movement of explosive materials. All explosive materials must be kept in locked magazines meeting...

  15. 27 CFR 555.109 - Identification of explosive materials.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... explosive materials. 555.109 Section 555.109 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Conduct of Business or Operations § 555.109 Identification of explosive materials. (a) General. Explosive...

  16. 27 CFR 555.109 - Identification of explosive materials.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Identification of explosive..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Conduct of Business or Operations § 555.109 Identification of explosive materials. (a) General. Explosive materials,...

  17. 27 CFR 555.205 - Movement of explosive materials.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Movement of explosive..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage § 555.205 Movement of explosive materials. All explosive materials must be kept in locked magazines meeting...

  18. Explosive events on the Sun.

    PubMed

    Harra, Louise K

    2002-12-15

    I describe two of the most dynamic and highly energetic phenomena in the Solar System--the explosive flares that can occur when plasma is confined by magnetic fields and the large-scale ejections of material known as 'coronal mass ejections'. These explosive events are poorly understood and yet occur in a variety of contexts in the Universe, ranging from planetary magnetospheres to active galactic nuclei. Understanding why flares and coronal mass ejections occur is a major goal across a wide range of space physics and astrophysics. Although explosive events from the Sun have dramatic effects on Earth, flares in other stars, for example, can be vastly more energetic and have an even more profound effect on their environment. We are now in the unprecedented position of having access to a number of space observatories dedicated to the Sun: the Yohkoh spacecraft, the Solar and Heliospheric Observatory, the Transition Region and Coronal Explorer and the Ramaty High Energy Solar Spectroscopic Imager. These cover a wide wavelength range from white light to gamma rays with both spectroscopy and imaging, and allow huge progress to be made in understanding the processes involved in such large explosions. The high-resolution data show dramatic and complex explosions of material on all spatial scales on the Sun. They have revealed that the Sun is constantly changing everywhere on its surface--something that was never imagined before. One of the mechanisms that has been proposed to account for the large energy release is magnetic reconnection. Recent observations from space increasingly support this view. This article will discuss those observations that support this model and also those that suggest different processes. The current space missions have given us an excellent insight into the actual explosive processes in the Sun. However, they have provided us with only a tantalizing glimpse of what causes the elusive trigger. Future missions such as Solar-B (the follow-on to Yohkoh), the Solar Terrestrial Relations Observatory, the Solar Dynamics Observatory and the Solar Orbiter mission will allow us to probe the trigger in a way that was not dreamt of a decade ago, by providing stereo views, measurements from Sun-grazing orbit, and much higher spatial, temporal and spectral resolution. It is an exciting time for solar physics and everything that we learn about the Sun will improve our ability to understand other magnetic phenomena in the Universe. PMID:12630406

  19. Gas chromatography/ion mobility spectrometry as a hyphenated technique for improved explosives detection and analysis

    NASA Technical Reports Server (NTRS)

    Mercado, AL; Marsden, Paul

    1995-01-01

    Ion Mobility Spectrometry (IMS) is currently being successfully applied to the problem of on-line trace detection of plastic and other explosives in airports and other facilities. The methods of sample retrieval primarily consist of batch sampling for particulate residue on a filter card for introduction into the IMS. The sample is desorbed into the IMS using air as the carrier and negative ions of the explosives are detected, some as an adduct with a reagent ion such as Cl(-). Based on studies and tests conducted by different airport authorities, this method seems to work well for low vapor pressure explosives such as RDX and PETN, as well as TNT that are highly adsorptive and can be found in nanogram quantities on contaminated surfaces. Recently, the changing terrorist threat and the adoption of new marking agents for plastic explosives has meant that the sample introduction and analysis capabilities of the IMS must be enhanced in order to keep up with other detector developments. The IMS has sufficient analytical resolution for a few threat compounds but the IMS Plasmogram becomes increasingly more difficult to interpret when the sample mixture gets more complex.

  20. Plastics in Perspective.

    ERIC Educational Resources Information Center

    Bergandine, David R.; Holm, D. Andrew

    The materials in this curriculum supplement, developed for middle school or high school science classes, present solid waste problems related to plastics. The set of curriculum materials is divided into two units to be used together or independently. Unit I begins by comparing patterns in solid waste from 1960 to 1990 and introducing methods for…

  1. Hydrodynamic Elastic Magneto Plastic

    Energy Science and Technology Software Center (ESTSC)

    1985-02-01

    The HEMP code solves the conservation equations of two-dimensional elastic-plastic flow, in plane x-y coordinates or in cylindrical symmetry around the x-axis. Provisions for calculation of fixed boundaries, free surfaces, pistons, and boundary slide planes have been included, along with other special conditions.

  2. Individual differences in behavioural plasticities.

    PubMed

    Stamps, Judy A

    2016-05-01

    Interest in individual differences in animal behavioural plasticities has surged in recent years, but research in this area has been hampered by semantic confusion as different investigators use the same terms (e.g. plasticity, flexibility, responsiveness) to refer to different phenomena. The first goal of this review is to suggest a framework for categorizing the many different types of behavioural plasticities, describe examples of each, and indicate why using reversibility as a criterion for categorizing behavioural plasticities is problematic. This framework is then used to address a number of timely questions about individual differences in behavioural plasticities. One set of questions concerns the experimental designs that can be used to study individual differences in various types of behavioural plasticities. Although within-individual designs are the default option for empirical studies of many types of behavioural plasticities, in some situations (e.g. when experience at an early age affects the behaviour expressed at subsequent ages), 'replicate individual' designs can provide useful insights into individual differences in behavioural plasticities. To date, researchers using within-individual and replicate individual designs have documented individual differences in all of the major categories of behavioural plasticities described herein. Another important question is whether and how different types of behavioural plasticities are related to one another. Currently there is empirical evidence that many behavioural plasticities [e.g. contextual plasticity, learning rates, IIV (intra-individual variability), endogenous plasticities, ontogenetic plasticities) can themselves vary as a function of experiences earlier in life, that is, many types of behavioural plasticity are themselves developmentally plastic. These findings support the assumption that differences among individuals in prior experiences may contribute to individual differences in behavioural plasticities observed at a given age. Several authors have predicted correlations across individuals between different types of behavioural plasticities, i.e. that some individuals will be generally more plastic than others. However, empirical support for most of these predictions, including indirect evidence from studies of relationships between personality traits and plasticities, is currently sparse and equivocal. The final section of this review suggests how an appreciation of the similarities and differences between different types of behavioural plasticities may help theoreticians formulate testable models to explain the evolution of individual differences in behavioural plasticities and the evolutionary and ecological consequences of individual differences in behavioural plasticities. PMID:25865135

  3. Sensitivity to friction for primary explosives.

    PubMed

    Matyáš, Robert; Šelešovský, Jakub; Musil, Tomáš

    2012-04-30

    The sensitivity to friction for a selection of primary explosives has been studied using a small BAM friction apparatus. The probit analysis was used for the construction of a sensitivity curve for each primary explosive tested. Two groups of primary explosives were chosen for measurement (a) the most commonly used industrially produced primary explosives (e.g. lead azide, tetrazene, dinol, lead styphnate) and (b) the most produced improvised primary explosives (e.g. triacetone triperoxide, hexamethylenetriperoxide diamine, mercury fulminate, acetylides of heavy metals). A knowledge of friction sensitivity is very important for determining manipulation safety for primary explosives. All the primary explosives tested were carefully characterised (synthesis procedure, shape and size of crystals). The sensitivity curves obtained represent a unique set of data, which cannot be found anywhere else in the available literature. PMID:22349715

  4. Spot test kit for explosives detection

    DOEpatents

    Pagoria, Philip F; Whipple, Richard E; Nunes, Peter J; Eckels, Joel Del; Reynolds, John G; Miles, Robin R; Chiarappa-Zucca, Marina L

    2014-03-11

    An explosion tester system comprising a body, a lateral flow membrane swab unit adapted to be removeably connected to the body, a first explosives detecting reagent, a first reagent holder and dispenser operatively connected to the body, the first reagent holder and dispenser containing the first explosives detecting reagent and positioned to deliver the first explosives detecting reagent to the lateral flow membrane swab unit when the lateral flow membrane swab unit is connected to the body, a second explosives detecting reagent, and a second reagent holder and dispenser operatively connected to the body, the second reagent holder and dispenser containing the second explosives detecting reagent and positioned to deliver the second explosives detecting reagent to the lateral flow membrane swab unit when the lateral flow membrane swab unit is connected to the body.

  5. Hazards of explosives dusts: Particle size effects

    SciTech Connect

    Cashdollar, K L; Hertzberg, M; Green, G M

    1992-02-01

    At the request of the Department of Energy, the Bureau of Mines has investigated the hazards of military explosives dispersed as dust clouds in a 20-L test chamber. In this report, the effect of particle size for HMX, HNS, RDX, TATB, and TNT explosives dusts is studied in detail. The explosibility data for these dusts are also compared to those for pure fuel dusts. The data show that all of the sizes of the explosives dusts that were studied were capable of sustaining explosions as dust clouds dispersed in air. The finest sizes (<10 [mu]m) of explosives dusts were less reactive than the intermediate sizes (20 to 60 [mu]m); this is opposite to the particle size effect observed previously for the pure fuel dusts. At the largest sizes studied, the explosives dusts become somewhat less reactive as dispersed dust clouds. The six sizes of the HMX dust were also studied as dust clouds dispersed in nitrogen.

  6. Seismic verification of underground explosions

    SciTech Connect

    Glenn, L.A.

    1985-06-01

    The first nuclear test agreement, the test moratorium, was made in 1958 and lasted until the Soviet Union unilaterally resumed testing in the atmosphere in 1961. It was followed by the Limited Test Ban Treaty of 1963, which prohibited nuclear tests in the atmosphere, in outer space, and underwater. In 1974 the Threshold Test Ban Treaty (TTBT) was signed, limiting underground tests after March 1976 to a maximum yield of 250 kt. The TTBT was followed by a treaty limiting peaceful nuclear explosions and both the United States and the Soviet Union claim to be abiding by the 150-kt yield limit. A comprehensive test ban treaty (CTBT), prohibiting all testing of nuclear weapons, has also been discussed. However, a verifiable CTBT is a contradiction in terms. No monitoring technology can offer absolute assurance that very-low-yield illicit explosions have not occurred. The verification process, evasion opportunities, and cavity decoupling are discussed in this paper.

  7. Elasticity of crystalline molecular explosives

    SciTech Connect

    Hooks, Daniel E.; Ramos, Kyle J.; Bolme, C. A.; Cawkwell, Marc J.

    2015-04-14

    Crystalline molecular explosives are key components of engineered explosive formulations. In precision applications a high degree of consistency and predictability is desired under a range of conditions to a variety of stimuli. Prediction of behaviors from mechanical response and failure to detonation initiation and detonation performance of the material is linked to accurate knowledge of the material structure and first stage of deformation: elasticity. The elastic response of pentaerythritol tetranitrate (PETN), cyclotrimethylene trinitramine (RDX), and cyclotetramethylene tetranitramine (HMX), including aspects of material and measurement variability, and computational methods are described in detail. Experimental determinations of elastic tensors are compared, and an evaluation of sources of error is presented. Furthermore, computed elastic constants are also compared for these materials and for triaminotrinitrobenzene (TATB), for which there are no measurements.

  8. Elasticity of crystalline molecular explosives

    DOE PAGESBeta

    Hooks, Daniel E.; Ramos, Kyle J.; Bolme, C. A.; Cawkwell, Marc J.

    2015-04-14

    Crystalline molecular explosives are key components of engineered explosive formulations. In precision applications a high degree of consistency and predictability is desired under a range of conditions to a variety of stimuli. Prediction of behaviors from mechanical response and failure to detonation initiation and detonation performance of the material is linked to accurate knowledge of the material structure and first stage of deformation: elasticity. The elastic response of pentaerythritol tetranitrate (PETN), cyclotrimethylene trinitramine (RDX), and cyclotetramethylene tetranitramine (HMX), including aspects of material and measurement variability, and computational methods are described in detail. Experimental determinations of elastic tensors are compared, andmore » an evaluation of sources of error is presented. Furthermore, computed elastic constants are also compared for these materials and for triaminotrinitrobenzene (TATB), for which there are no measurements.« less

  9. Printable sensors for explosive detonation

    SciTech Connect

    Griffith, Matthew J. Cooling, Nathan A.; Elkington, Daniel C.; Belcher, Warwick J.; Dastoor, Paul C.; Muller, Elmar

    2014-10-06

    Here, we report the development of an organic thin film transistor (OTFT) based on printable solution processed polymers and employing a quantum tunnelling composite material as a sensor to convert the pressure wave output from detonation transmission tubing (shock tube) into an inherently amplified electronic signal for explosives initiation. The organic electronic detector allows detection of the signal in a low voltage operating range, an essential feature for sites employing live ordinances that is not provided by conventional electronic devices. We show that a 30-fold change in detector response is possible using the presented detector assembly. Degradation of the OTFT response with both time and repeated voltage scans was characterised, and device lifetime is shown to be consistent with the requirements for on-site printing and usage. The integration of a low cost organic electronic detector with inexpensive shock tube transmission fuse presents attractive avenues for the development of cheap and simple assemblies for precisely timed initiation of explosive chains.

  10. Printable sensors for explosive detonation

    NASA Astrophysics Data System (ADS)

    Griffith, Matthew J.; Cooling, Nathan A.; Elkington, Daniel C.; Muller, Elmar; Belcher, Warwick J.; Dastoor, Paul C.

    2014-10-01

    Here, we report the development of an organic thin film transistor (OTFT) based on printable solution processed polymers and employing a quantum tunnelling composite material as a sensor to convert the pressure wave output from detonation transmission tubing (shock tube) into an inherently amplified electronic signal for explosives initiation. The organic electronic detector allows detection of the signal in a low voltage operating range, an essential feature for sites employing live ordinances that is not provided by conventional electronic devices. We show that a 30-fold change in detector response is possible using the presented detector assembly. Degradation of the OTFT response with both time and repeated voltage scans was characterised, and device lifetime is shown to be consistent with the requirements for on-site printing and usage. The integration of a low cost organic electronic detector with inexpensive shock tube transmission fuse presents attractive avenues for the development of cheap and simple assemblies for precisely timed initiation of explosive chains.

  11. Applying NASA's explosive seam welding

    NASA Astrophysics Data System (ADS)

    Bement, Laurence J.

    1991-12-01

    The status of an explosive seam welding process, which was developed and evaluated for a wide range of metal joining opportunities, is summarized. The process employs very small quantities of explosive in a ribbon configuration to accelerate a long-length, narrow area of sheet stock into a high-velocity, angular impact against a second sheet. At impact, the oxide films of both surface are broken up and ejected by the closing angle to allow atoms to bond through the sharing of valence electrons. This cold-working process produces joints having parent metal properties, allowing a variety of joints to be fabricated that achieve full strength of the metals employed. Successful joining was accomplished in all aluminum alloys, a wide variety of iron and steel alloys, copper, brass, titanium, tantalum, zirconium, niobium, telerium, and columbium. Safety issues were addressed and are as manageable as many currently accepted joining processes.

  12. Explosives detection system and method

    DOEpatents

    Reber, Edward L.; Jewell, James K.; Rohde, Kenneth W.; Seabury, Edward H.; Blackwood, Larry G.; Edwards, Andrew J.; Derr, Kurt W.

    2007-12-11

    A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.

  13. Explosive percolation: A numerical analysis

    NASA Astrophysics Data System (ADS)

    Radicchi, Filippo; Fortunato, Santo

    2010-03-01

    Percolation is one of the most studied processes in statistical physics. A recent paper by Achlioptas [Science 323, 1453 (2009)] showed that the percolation transition, which is usually continuous, becomes discontinuous (“explosive”) if links are added to the system according to special cooperative rules (Achlioptas processes). In this paper, we present a detailed numerical analysis of Achlioptas processes with product rule on various systems, including lattices, random networks á la Erdös-Rényi, and scale-free networks. In all cases, we recover the explosive transition by Achlioptas However, the explosive percolation transition is kind of hybrid as, despite the discontinuity of the order parameter at the threshold, one observes traces of analytical behavior such as power-law distributions of cluster sizes. In particular, for scale-free networks with degree exponent λ<3 , all relevant percolation variables display power-law scaling, just as in continuous second-order phase transitions.

  14. Liquids and homemade explosive detection

    NASA Astrophysics Data System (ADS)

    Ellenbogen, Michael; Bijjani, Richard

    2009-05-01

    Excerpt from the US Transportation Security Agency website: "The ban on liquids, aerosols and gels was implemented on August 10 after a terrorist plot was foiled. Since then, experts from around the government, including the FBI and our national labs have analyzed the information we now have and have conducted extensive explosives testing to get a better understanding of this specific threat." In order to lift the ban and ease the burden on the flying public, Reveal began an extensive effort in close collaboration with the US and several other governments to help identify these threats. This effort resulted in the successful development and testing of an automated explosive detection system capable of resolving these threats with a high probability of detection and a low false alarm rate. We will present here some of the methodology and approach we took to address this problem.

  15. Applying NASA's explosive seam welding

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.

    1991-01-01

    The status of an explosive seam welding process, which was developed and evaluated for a wide range of metal joining opportunities, is summarized. The process employs very small quantities of explosive in a ribbon configuration to accelerate a long-length, narrow area of sheet stock into a high-velocity, angular impact against a second sheet. At impact, the oxide films of both surface are broken up and ejected by the closing angle to allow atoms to bond through the sharing of valence electrons. This cold-working process produces joints having parent metal properties, allowing a variety of joints to be fabricated that achieve full strength of the metals employed. Successful joining was accomplished in all aluminum alloys, a wide variety of iron and steel alloys, copper, brass, titanium, tantalum, zirconium, niobium, telerium, and columbium. Safety issues were addressed and are as manageable as many currently accepted joining processes.

  16. Fluid Instabilities inside Astrophysical Explosions

    NASA Astrophysics Data System (ADS)

    Chen, Ke-Jung; Woosley, Stan; Heger, Alexander; Almgren, Ann; Zheng, Weiqun

    2014-11-01

    We present our results from the simulations of fluid instabilities inside supernovae with a new radiation-hydrodynamic code, CASTRO. Massive stars are ten times more massive than Sun. Observational and theoretical studies suggest that these massive stars tend to end their lives with energetic explosions, so-called supernovae. Many fluid instabilities occur during the supernova explosions. The fluid instabilities can be driven by hydrodynamics, nuclear burning, or radiation. In this talk, we discuss about the possible physics of fluid instabilities found in our simulations and how the resulting mixing affects the observational signatures of supernovae. This work was supported by the DOE HEP Program under contract DE-SC0010676; the National Science Foundation (AST 0909129) and the NASA Theory Program (NNX14AH34G).

  17. Studying stellar explosions with Athena

    NASA Astrophysics Data System (ADS)

    O'Brien, Paul; Jonker, Peter

    2015-08-01

    Athena is the second large mission selected in the ESA Cosmic Vision plan. With its large collecting area, high spectral-energy resolution (X-IFU instrument) and impressive grasp (WFI instrument), Athena will truly revolutionise X-ray astronomy. The most prodigious sources of high-energy photons are often transitory in nature. Athena will provide the sensitivity and spectral resolution coupled with rapid response to enable the study of the dynamic sky. Potential sources include: distant Gamma-Ray Bursts to probe the reionisation epoch and find ‘missing’ baryons in the cosmic web; tidal disruption events to reveal dormant supermassive and intermediate-mass black holes; and supernova explosions to understand progenitors and their environments. We illustrate Athena’s capabilities and show how it will be able to constrain the nature of explosive transients including gas metallicity and dynamics.

  18. Investigation on the explosive welding mechanism of corrosion-resisting aluminum and stainless steel tubes through finite element simulation and experiments

    NASA Astrophysics Data System (ADS)

    Sui, Guo-Fa; Li, Jin-Shan; Li, Hong-Wei; Sun, Feng; Zhang, Tie-Bang; Fu, Heng-Zhi

    2012-02-01

    To solve the difficulty in the explosive welding of corrosion-resistant aluminum and stainless steel tubes, three technologies were proposed after investigating the forming mechanism through experiments. Then, a 3D finite element model was established for systematic simulations in the parameter determination. The results show that the transition-layer approach, the coaxial initial assembly of tubes with the top-center-point the detonation, and the systematic study by numerical modeling are the key technologies to make the explosive welding of LF6 aluminum alloy and 1Cr18Ni9Ti stainless steel tubes feasible. Numerical simulation shows that radial contraction and slope collision through continuous local plastic deformation are necessary for the good bonding of tubes. Stand-off distances between tubes ( D 1 and D 2) and explosives amount ( R) have effect on the plastic deformation, moving velocity, and bonding of tubes. D 1 of 1 mm, D 2 of 2 mm, and R of 2/3 are suitable for the explosive welding of LF6-L2-1Cr18Ni9Ti three-layer tubes. The plastic strain and moving velocity of the flyer tubes increase with the increase of stand-off distance. More explosives ( R>2/3) result in the asymmetrical distribution of plastic strain and non-bonding at the end of detonation on the tubes.

  19. Plastics (Environmental Health Student Portal)

    MedlinePlus

    ... Pollutants Natural Disasters Drinking Water Waterborne Diseases & Illnesses Water Cycle Water Treatment Videos Games Experiments For Teachers Home ... Pollutants Natural Disasters Drinking Water Waterborne Diseases & Illnesses Water Cycle Water Treatment Plastics The Basics Plastics play a ...

  20. American Society of Plastic Surgeons

    MedlinePlus

    ... Male Specific Gynecomastia Surgery Hair Replacement Men and Plastic Surgery Minimally Invasive Botulinum Toxin Chemical Peel Dermabrasion Dermal ... E. Patient Safety Do Your Homework Dangers of Plastic Surgery Tourism Patient and Consumer Information Before & After Find ...

  1. Explosive Formulation Code Naming SOP

    SciTech Connect

    Martz, H. E.

    2014-09-19

    The purpose of this SOP is to provide a procedure for giving individual HME formulations code names. A code name for an individual HME formulation consists of an explosive family code, given by the classified guide, followed by a dash, -, and a number. If the formulation requires preparation such as packing or aging, these add additional groups of symbols to the X-ray specimen name.

  2. Preventing large-battery explosions

    NASA Astrophysics Data System (ADS)

    Cummins, D.; Pangeri, S. F.

    1980-08-01

    This information circular presents a brief history of the lead-acid battery and describes ways to prevent serious injury from battery explosions when servicing and charging lead-acid batteries, particularly in the surface mining industry. The Mining Safety and Health Administration (MSHA), U.S. Consumer Product Safety Commission, battery maufacturers, and the mining industry have all contributed information as well as recommendations for injury-free handling for this report.

  3. Splicing Wires Permanently With Explosives

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Kushnick, Anne C.

    1990-01-01

    Explosive joining process developed to splice wires by enclosing and metallurgically bonding wires within copper sheets. Joints exhibit many desirable characteristics, 100-percent conductivity and strength, no heat-induced annealing, no susceptibility to corrosion in contacts between dissimilar metals, and stability at high temperature. Used to join wires to terminals, as well as to splice wires. Applicable to telecommunications industry, in which millions of small wires spliced annually.

  4. Thermodynamic States in Explosion Fields

    SciTech Connect

    Kuhl, A L

    2010-03-12

    We investigate the thermodynamic states occurring in explosion fields from condensed explosive charges. These states are often modeled with a Jones-Wilkins-Lee (JWL) function. However, the JWL function is not a Fundamental Equation of Thermodynamics, and therefore cannot give a complete specification of such states. We use the Cheetah code of Fried to study the loci of states of the expanded detonation products gases from C-4 charges, and their combustion products air. In the Le Chatelier Plane of specific-internal-energy versus temperature, these loci are fit with a Quadratic Model function u(T), which has been shown to be valid for T < 3,000 K and p < 1k-bar. This model is used to derive a Fundamental Equation u(v,s) for C-4. Given u(v,s), one can use Maxwell's Relations to derive all other thermodynamic functions, such as temperature: T(v,s), pressure: p(v,s), enthalpy: h(v,s), Gibbs free energy: g(v,s) and Helmholz free energy: f(v,s); these loci are displayed in figures for C-4. Such complete equations of state are needed for numerical simulations of blast waves from explosive charges, and their reflections from surfaces.

  5. Fish kill from underwater explosions

    USGS Publications Warehouse

    Stuart, David J.

    1962-01-01

    The U.S. Geological Survey has used 23 different shotpoints during two seasons of field work in our seismic study of crustal structure in western United States. Without exception, it has been found that under-water shotpoints result in a more efficient conversion of explosive energy into seismic energy than do drilled-hole shotpoints. This experience, together with elimination of drilling costs, has led to the use of underwater shotpoints wherever possible. Three of the 23 shotpoints were in the Pacific Ocean, and for these we have no detailed information on the fish kill. Another six shotpoints were located in inland bodies of water. These are: * Soda Lake near Fallon, Nevada * Mono Lake near Lee Vining, California * Lake Mead near Boulder City, Nevada * Shasta Lake near Redding, California * C.J. Strike Reservoir near Bruneau, Idaho * Lucky Peak Reservoir near Boise, Idaho The 22 high-explosive charges, weighing a total of 95,100 pounds, that were fired in lakes containing fish life resulted in the known death of 2,413 game fish with a total weight of 759 pounds. The average mortality was 110 game fish or 34.5 pounds of game fish killed per average shot of 4,325 pounds of high-explosives.

  6. Energy transfer in solid explosives

    SciTech Connect

    Tarver, C.M.; Fried, L.E.; Ruggiero, A.J.; Calef, D.F.

    1993-07-01

    The nonequilibrium Zeldovich-von Neumann-Doring theory of detonation in solid explosives is extended to include recent nanosecond and picosecond experimental and theoretical results on each of the four main regions of the reaction zone. The first region is the three-dimensional, Mach stem dominated leading shock front which excites the phonon modes of the explosive molecules in less than a picosecond. The second region is the multiphonon up-pumping process in which the excited phonons anharmonically couple to the low frequency (doorway) vibrational modes which in turn equilibrate with the higher frequency modes by internal vibrational redistribution. This process may require on the order of tens of picoseconds. The third region is the chemical reconstitution region in which the vibrationally equilibrated transition state decomposes in a series of chain reaction steps into highly vibrationally excited diatomic and triatomic molecules in approximately one nanosecond. The fourth region is dominated by vibrational deexcitation and solid species formation as chemical and thermal equilibrium is approached. This is the region measured by current nanosecond resolution techniques and can last from nanoseconds to microseconds depending on the oxygen balance of the solid explosive.

  7. Plastics for Elementary School Children

    ERIC Educational Resources Information Center

    Hanson, Jack

    1977-01-01

    Describes three plastics projects (which involve making a styrene fishing bobber, an acrylic salad fork and spoon set, and acetate shrink art) designed to provide elementary level students an opportunity to work with plastics and to learn about careers in plastics production and distribution. (TA)

  8. Results of tests for explosives in luggage from fast-neutron time-of-flight transmission measurements

    NASA Astrophysics Data System (ADS)

    Overley, Jack C.; Chmelik, Michael S.; Rasmussen, R. J.; Sieger, G. E.; Schofield, R. M. S.; Lefevre, Harlan W.

    1997-02-01

    Energy-dependent neutron attenuations measured by time-of- flight techniques are fitted with measured cross sections to determine projected number densities of H, C, N, and O in each 3 by 3-cm2 pixel of a suitcase. Attenuations due to other elements are lumped together as element X. Number densities are normalize by the total to reduce effects of variable thickness. Normalized number densities are constrained to lie in a 4D space. That space is finely binned. A fifth dimension contains six bins of N + O density, as deduced from average suitcase thickness and measured projected number densities. Each bin is labeled with the probability of encountering an explosive, as determined from distributions of elements from simulated explosive and nonexplosive situations. Probabilities for individual pixels are combined to produce an overall probability of an explosive suitcase. About 130 measurements involving 50 suitcases have been made. For about half of those measurements, an explosive was placed in the suitcase. Ten different plastic explosives were used in varying amounts and configurations. When suitcases are ordered by explosive probability, and a threshold is set to minimize errors, the false alarm rate is about 2 percent and the explosive detection rate is about 88 percent. Potential improvements are discussed.

  9. The Acoustics of Volcanic Explosions

    NASA Astrophysics Data System (ADS)

    Garces, Milton A.

    1995-01-01

    This thesis consists of an analytical model for acoustic wave propagation in volcanoes and a comparison of the model's predictions with sounds recorded at Stromboli Volcano, Italy. The theoretical model yields the airborne sound field radiated by a magmatic conduit that is excited into resonance by an explosive source. The output of this model provides analytical solutions for the acoustic field in the magma and in the atmosphere as functions of frequency. At low frequencies the spatial structure of the field in the atmosphere is dominated by diffraction at the corner of the vent. At high frequencies, each mode is radiated into the atmosphere as a beam of sound, whose angle of elevation is determined by Snell's Law. The predicted acoustic field spectrum in the atmosphere has a peaked structure due to the horizontal and vertical modes of the magmatic conduit. The spectrum is transformed into a synthetic pressure pulse by numerical Fourier inversion. The second part of the thesis consists of a comparison between airborne acoustic data recorded at Stromboli Volcano and the predictions of the theory. By comparing the model's output with the acoustic data, estimates are obtained for the sound speed, void fraction and viscosity of the magma, as well as the length and radius of the conduits at Stromboli. Both theoretical and observed energy spectra exhibit (1) a concentration of energy in the infrasound region, which is associated with the first few longitudinal resonances; (2) a broad minimum corresponding to a suppressed longitudinal mode, which is explained by a source depth located near the antinodes for this mode; and (3) an abrupt rise in the spectral levels in the low audio region, which may be due to onset of radial resonances. In the time domain, the theoretical pressure pulses show a random character which is due to the propagation effect of conduit reverberation. Features of these synthetic pressure signals are consistent with those of the explosion transients. A separate analysis was made of Western and Eastern crater explosion signatures recorded at Stromboli. The results of the modeling suggest that W crater may be represented as a long and wide conduit with a high sound speed and viscosity. A superposition of synthetic pulses mimics well the explosion signatures of the W crater, implying these explosions are composed of many bursts of short duration. The E crater is modeled as a short and narrow conduit of low sound speed and viscosity. E crater explosive events are dominant in the infrasound region, but may be masked by degassing in the audio region. The difference between W and E crater explosions may be attributed to a higher gas content and temperature of the E crater magma. The success of the modeling indicates that the low-frequency temporal and spectral properties of volcanic sounds are determined by the normal modes of a resonant magmatic conduit, and that these sounds contain substantial information about the internal processes and structure of active volcanoes.

  10. Data base of chemical explosions in Kazakhstan

    SciTech Connect

    Demin, V.N.; Malahova, M.N.; Martysevich, P.N.; Mihaylova, N.N.; Nurmagambetov, A.; Kopnichev, Yu.F. D.; Edomin, V.I.

    1996-12-01

    Within the bounds of this report, the following works were done: (1) Information about explosion quarries, located in Southern, Eastern and Northern Kasakstan was summarized. (2) The general information about seismicity of areas of location of explosion quarries was adduced. (3) The system of observation and seismic apparatus, recording the local earthquakes and quarry explosions at the territory of Kazakstan were described. (4) Data base of quarry explosions, that were carried out in Southern, Eastern and Northern Kazakstan during 1995 and first half of 1996 year was adduced. (5) Upon the data of registration of explosions in Southern Kazakstan the correlative dependences between power class of explosions and summary weight of charge were constructed. (6) Seismic records of quarry explosions were adduced. It is necessary to note, that the collection of data about quarry explosions in Kazakstan in present time is very difficult task. Organizations, that makes these explosions, are always suffering reorganizations and sometimes it is actually impossible to receive all the necessary information. Some quarries are situated in remote, almost inaccessible regions, and within the bounds of supplier financing not the every quarry was in success to visit. So the present data base upon the chemical explosions for 1995 is not full and in further it`s expansion is possible.

  11. Totally confined explosive welding. [apparatus to reduce noise level and protect personnel during explosive bonding

    NASA Technical Reports Server (NTRS)

    Bement, L. J. (Inventor)

    1974-01-01

    A method and associated apparatus for confining the undesirable by-products and limiting noise of explosive welding are discussed. The apparatus consists fo a simple enclosure into which the explosive is placed and within which the explosion occurs. The shape of the enclosure, the placement of the explosive, and the manner in which the enclosure is placed upon the material to be welded determine the force of the explosion transmitted to the proposed bond area. The explosion is totally confined within the enclosure thus reducing the noise level and preventing debris from being strewn about to contaminate the weld area or create personnel hazards.

  12. Endocannabinoids in striatal plasticity

    PubMed Central

    Lovinger, David M.; Mathur, Brian N.

    2016-01-01

    SUMMARY Endocannabinoids (eCBs) are lipid metabolites found throughout the nervous system that modulate synaptic plasticity mainly via actions on the cannabinoid 1 (CB1) receptor. Within the striatum, eCBs and CB1Rs initiate both short- and long-lasting synaptic depression at intrinsic GABAergic synapses and glutamatergic synapses made by cortical afferents. Recent studies have explored the mechanisms underlying eCB-mediated synaptic depression, and the role of this plasticity in striatal function. Dopamine (DA) and its receptors promote eCB-mediated depression of glutamatergic synapses, and dopamine depletion in animal models alters corticostriatal synapses in ways that may contribute to Parkinson’s disease (PD). A growing body of literature indicates that alterations in eCB signaling occur in PD patients, suggesting possible therapeutic approaches targeting this neuromodulatory system. PMID:22166411

  13. Stress-gradient plasticity

    PubMed Central

    Chakravarthy, Srinath S.; Curtin, W. A.

    2011-01-01

    A new model, stress-gradient plasticity, is presented that provides unique mechanistic insight into size-dependent phenomena in plasticity. This dislocation-based model predicts strengthening of materials when a gradient in stress acts over dislocation source–obstacle configurations. The model has a physical length scale, the spacing of dislocation obstacles, and is validated by several levels of discrete-dislocation simulations. When incorporated into a continuum viscoplastic model, predictions for bending and torsion in polycrystalline metals show excellent agreement with experiments in the initial strengthening and subsequent hardening as a function of both sample-size dependence and grain size, when the operative obstacle spacing is proportional to the grain size. PMID:21911403

  14. Growth factors and plasticity.

    PubMed

    Sizonenko, Stéphane V; Bednarek, Nathalie; Gressens, Pierre

    2007-08-01

    Neuroprotective strategies can prevent lesions from getting worse but agents that have neurotrophic properties can also affect repair in a developing brain. Although prevention and treatment in the early stages of brain lesions are desirable, delayed cell death or improved post-lesion plasticity are the only realistic targets in many cases. Several trophic factors can limit delayed cell death in animal models of perinatal brain damage. In addition, melatonin and brain-derived neurotrophic factor have been shown to promote post-lesion plasticity following neonatal excitotoxic white-matter damage in newborn mice. Despite these promising results, additional preclinical data are required for most of the trophic factors that have been tested, although some candidate drugs, e.g. melatonin or erythropoietin, might reach clinical trials in the near future. PMID:17336172

  15. Facial plastic surgery database.

    PubMed

    Mendelsohn, M; Conrad, K

    1994-02-01

    Every facial plastic surgeon accumulates a vast library of professional slides and photographs that document his work. Manual cataloguing of the clinical and operative documentation is time consuming and provides limited analysis capabilities. The facial plastic surgery database is a state-of-the-art computer programme that allows the surgeon to sort and locate slides and photographs. Designed for the computer novice, it utilises a simple coding system to permit rapid data input. The codes can be tailored to allow for new procedures or alternative practice styles. There are sophisticated searching routines to quickly find slides and photographs based on any combination of patients and operative criteria. The database also includes an online colour atlas and workspace for recording of presentations. There are automated routines to analyse patients' clinical features, operative trends, and surgical results. Ultimately, examination of this data can be used to facilitate peer review, research, and self-education. PMID:8170012

  16. Compensatory plasticity: time matters

    PubMed Central

    Lazzouni, Latifa; Lepore, Franco

    2014-01-01

    Plasticity in the human and animal brain is the rule, the base for development, and the way to deal effectively with the environment for making the most efficient use of all the senses. When the brain is deprived of one sensory modality, plasticity becomes compensatory: the exception that invalidates the general loss hypothesis giving the opportunity of effective change. Sensory deprivation comes with massive alterations in brain structure and function, behavioral outcomes, and neural interactions. Blind individuals do as good as the sighted and even more, show superior abilities in auditory, tactile and olfactory processing. This behavioral enhancement is accompanied with changes in occipital cortex function, where visual areas at different levels become responsive to non-visual information. The intact senses are in general used more efficiently in the blind but are also used more exclusively. New findings are disentangling these two aspects of compensatory plasticity. What is due to visual deprivation and what is dependent on the extended use of spared modalities? The latter seems to contribute highly to compensatory changes in the congenitally blind. Short-term deprivation through the use of blindfolds shows that cortical excitability of the visual cortex is likely to show rapid modulatory changes after few minutes of light deprivation and therefore changes are possible in adulthood. However, reorganization remains more pronounced in the congenitally blind. Cortico-cortical pathways between visual areas and the areas of preserved sensory modalities are inhibited in the presence of vision, but are unmasked after loss of vision or blindfolding as a mechanism likely to drive cross-modal information to the deafferented visual cortex. The development of specialized higher order visual pathways independently from early sensory experience is likely to preserve their function and switch to the intact modalities. Plasticity in the blind is also accompanied with neurochemical and morphological changes; both intrinsic connectivity and functional coupling at rest are altered but are likewise dependent on different sensory experience and training. PMID:24971056

  17. 77 FR 54930 - Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A Subsidiary of Plastics...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    ... determination was published in the Federal Register on Monday, July 23, 2012 (77 FR 43123). ] At the request of... Employment and Training Administration Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A Subsidiary of Plastics Acquisitions Inc., Including On-Site Leased Workers From Kelly Services and...

  18. A NIST standard reference material (SRM) to support the detection of trace explosives.

    PubMed

    MacCrehan, William A

    2009-09-01

    SRM 2905 Trace Particulate Explosives was developed to simulate the residues produced by handling plastic and military explosives. A series of nine candidate materials were prepared by coating chromatographic supports with either Composition C-4 (containing RDX (hexahydro-1,3,5-trinitro-1,3,5-Triazine) and HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-Tetrazocine)) or TNT (2,4,6-trinitrotoluene). Criteria for selection of the best material for the SRM included: coating efficiency, extractability with organic solvents, thermal storage stability, consistency of the particle size with fingerprint residues, and suitability for calibration of trace explosives detectors. The final base material selected for the SRM was octadecylsilane-modified silica (C(18)) with a nominal 20-30 microm particle size. Four materials comprise the SRM, with two nominal concentrations of explosive, 0.01% and 0.1% (mass fraction) for both C-4 and TNT, respectively. The final certified concentrations were determined by liquid chromatography (LC) with ultraviolet absorbance detection (LC/UV) and a liquid chromatography with mass spectrometric (LC/MS) method using negative ion atmospheric pressure ionization (APCI(-)) with an acetate ionization additive that improves quantitation. The SRM was tested on a table-top field explosives detector based ion mobility spectrometry (IMS). PMID:19637901

  19. Respiratory Muscle Plasticity

    PubMed Central

    Gransee, Heather M.; Mantilla, Carlos B.; Sieck, Gary C.

    2014-01-01

    Muscle plasticity is defined as the ability of a given muscle to alter its structural and functional properties in accordance with the environmental conditions imposed on it. As such, respiratory muscle is in a constant state of remodeling, and the basis of muscle’s plasticity is its ability to change protein expression and resultant protein balance in response to varying environmental conditions. Here, we will describe the changes of respiratory muscle imposed by extrinsic changes in mechanical load, activity, and innervation. Although there is a large body of literature on the structural and functional plasticity of respiratory muscles, we are only beginning to understand the molecular-scale protein changes that contribute to protein balance. We will give an overview of key mechanisms regulating protein synthesis and protein degradation, as well as the complex interactions between them. We suggest future application of a systems biology approach that would develop a mathematical model of protein balance and greatly improve treatments in a variety of clinical settings related to maintaining both muscle mass and optimal contractile function of respiratory muscles. PMID:23798306

  20. Plasticity of loudness perception

    NASA Astrophysics Data System (ADS)

    Formby, Craig; Sherlock, Laguinn P.; Gold, Susan L.

    2002-05-01

    Evidence from the management of tinnitus and hyperacusis suggests that loudness perception is plastic and adaptable. We have undertaken a study to evaluate this idea. The motivation followed from clinical observations suggesting that the magnitude of perceived loudness and, in turn, the rate of loudness growth can be manipulated either upward or downward by prolonged reduction or enhancement in the level of background sound to which a listener is exposed. Accordingly, volunteers were fitted bilaterally with in-the-ear noise instruments (NI treatment) or sound-attenuating earplugs (EP treatment). Both treatments produced audibility threshold shifts, mainly above 1000 Hz. The effects of each treatment were evaluated after 2 weeks of continuous use relative to pretreatment loudness response data obtained using the Contour Test of loudness perception. The resulting loudness data for warble tones revealed opposite patterns of plasticity for the two treatments, with steeper and shallower (than pretreatment) loudness growth functions measured, respectively, for the EP and NI treatments. These effects were significantly different for loudness response categories judged to be comfortably loud or louder at both 500 and 2000 Hz. Possible mechanisms for this apparent plasticity of loudness will be discussed. [Research supported by NIDCD.

  1. Plastic footwear for leprosy.

    PubMed

    Antia, N H

    1990-03-01

    The anaesthetic foot in leprosy poses the most major problem in the rehabilitation of its patients. Various attempts have been made to produce protective footwear such as the microcellular rubber-car-tyre sandals. Unfortunately these attempts have had little success on a large scale because of the inability to produce them in large numbers and the stigma attached to such unusual footwear. While such footwear may be superior to the 'tennis' shoe in protecting the foot from injury by the penetration of sharp objects, it fails to distribute the weight-bearing forces which is the major cause of plantar damage and ulceration in the anaesthetic foot. This can be achieved by providing rigidity to the sole, as demonstrated by the healing of ulcers in plaster of paris casts or the rigid wooden clog. A new type of moulded plastic footwear has been evolved in conjunction with the plastic footwear industry which provides footwear that can be mass produced at a low price and which overcomes the stigma of leprosy. Controlled rigidity is provided by the incorporation of a spring steel shank between the sponge insole and the hard wearing plastic sole. Trials have demonstrated both the acceptability of the footwear and its protective effects as well as its hard wearing properties. PMID:2319903

  2. Plasticity of amyloid fibrils†

    PubMed Central

    Wetzel, Ronald; Shivaprasad, Shankaramma; Williams, Angela D.

    2008-01-01

    In experiments designed to characterize the basis of amyloid fibril stability through mutational analysis of the Aβ(1-40) molecule, fibrils exhibit consistent, significant structural malleability. In these results, and in other properties, amyloid fibrils appear to more resemble plastic materials generated from synthetic polymers than they do globular proteins. Thus, like synthetic polymers and plastics, amyloid fibrils exhibit both polymorphism, the ability of one polypeptide to form aggregates of different morphologies, and isomorphism, the ability of different polypeptides to grow into a fibrillar amyloid morphology. This view links amyloid with the prehistorical and 20th Century use of proteins as starting materials to make films, fibers, and plastics, and with the classic protein fiber stretching experiments of the Astbury group. Viewing amyloid from the point of view of the polymer chemist may shed new light on issues such as the role of protofibrils in the mechanism of amyloid formation, the biological potency of fibrils, and the prospects for discovering inhibitors of amyloid fibril formation. PMID:17198370

  3. Microelectronics plastic molded packaging

    SciTech Connect

    Johnson, D.R.; Palmer, D.W.; Peterson, D.W.

    1997-02-01

    The use of commercial off-the-shelf (COTS) microelectronics for nuclear weapon applications will soon be reality rather than hearsay. The use of COTS for new technologies for uniquely military applications is being driven by the so-called Perry Initiative that requires the U.S. Department of Defense (DoD) to accept and utilize commercial standards for procurement of military systems. Based on this philosophy, coupled with several practical considerations, new weapons systems as well as future upgrades will contain plastic encapsulated microelectronics. However, a conservative Department of Energy (DOE) approach requires lifetime predictive models. Thus, the focus of the current project is on accelerated testing to advance current aging models as well as on the development of the methodology to be used during WR qualification of plastic encapsulated microelectronics. An additional focal point involves achieving awareness of commercial capabilities, materials, and processes. One of the major outcomes of the project has been the definition of proper techniques for handling and evaluation of modern surface mount parts which might be used in future systems. This program is also raising the familiarity level of plastic within the weapons complex, allowing subsystem design rules accommodating COTS to evolve. A two year program plan is presented along with test results and commercial interactions during this first year.

  4. Adipose tissue plasticity from WAT to BAT and in between

    PubMed Central

    Lee, Yun-Hee; Mottillo, Emilio P.; Granneman, James G.

    2015-01-01

    Adipose tissue plays an essential role in regulating energy balance through its metabolic, cellular and endocrine functions. Adipose tissue has been historically classified into anabolic white adipose tissue and catabolic brown adipose tissue. An explosion of new data, however, points to the remarkable heterogeneity among the cells types that can become adipocytes, as well as the inherent metabolic plasticity of mature cells. These data indicate that targeting cellular and metabolic plasticity of adipose tissue might provide new avenues for treatment of obesity-related diseases. This review will discuss the developmental origins of adipose tissue, the cellular complexity of adipose tissues, and the identification of progenitors that contribute to adipogenesis throughout development. We will touch upon the pathological remodelling of adipose tissue and discuss how our understanding of adipose tissue remodeling can uncover new therapeutic targets. PMID:23688783

  5. New perspectives in plastic biodegradation.

    PubMed

    Sivan, Alex

    2011-06-01

    During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution. PMID:21356588

  6. 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.

  7. Explosives Detection: Exploitation of the Physical Signatures

    NASA Astrophysics Data System (ADS)

    Atkinson, David

    2010-10-01

    Explosives based terrorism is an ongoing threat that is evolving with respect to implementation, configuration and materials used. There are a variety of devices designed to detect explosive devices, however, each technology has limitations and operational constraints. A full understanding of the signatures available for detection coupled with the array of detection choices can be used to develop a conceptual model of an explosives screening operation. Physics based sensors provide a robust approach to explosives detection, typically through the identification of anomalies, and are currently used for screening in airports around the world. The next generation of detectors for explosives detection will need to be more sensitive and selective, as well as integrate seamlessly with devices focused on chemical signatures. An appreciation for the details of the physical signature exploitation in cluttered environments with time, space, and privacy constraints is necessary for effective explosives screening of people, luggage, cargo, and vehicles.

  8. Eigenvalue Detonation of Combined Effects Aluminized Explosives

    NASA Astrophysics Data System (ADS)

    Capellos, Christos; Baker, Ernest; Balas, Wendy; Nicolich, Steven; Stiel, Leonard

    2007-06-01

    This paper reports on the development of theory and performance for recently developed combined effects aluminized explosives. Traditional high energy explosives used for metal pushing incorporate high loading percentages of HMX or RDX, whereas blast explosives incorporate some percentage of aluminum. However, the high blast explosives produce increased blast energies, with reduced metal pushing capability due to late time aluminum reaction. Metal pushing capability refers to the early volume expansion work produced during the first few volume expansions associated with cylinder wall velocities and Gurney energies. Our Recently developed combined effects aluminized explosives (PAX-29C, PAX-30, PAX-42) are capable of achieving excellent metal pushing and high blast energies. Traditional Chapman-Jouguet detonation theory does not explain the observed detonation states achieved by these combined effects explosives. This work demonstrates, with the use of cylinder expansion data and thermochemical code calculations (JAGUAR and CHEETAH), that eigenvalue detonation theory explains the observed behavior.

  9. Interfacial interactions between plastic particles in plastics flotation.

    PubMed

    Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Fu, Jian-gang; Lin, Qing-quan; Liu, You-nian

    2015-12-01

    Plastics flotation used for recycling of plastic wastes receives increasing attention for its industrial application. In order to study the mechanism of plastics flotation, the interfacial interactions between plastic particles in flotation system were investigated through calculation of Lifshitz-van der Waals (LW) function, Lewis acid-base (AB) Gibbs function, and the extended Derjaguin-Landau-Verwey-Overbeek potential energy profiles. The results showed that van der Waals force between plastic particles is attraction force in flotation system. The large hydrophobic attraction, caused by the AB Gibbs function, is the dominant interparticle force. Wetting agents present significant effects on the interfacial interactions between plastic particles. It is found that adsorption of wetting agents promotes dispersion of plastic particles and decreases the floatability. Pneumatic flotation may improve the recovery and purity of separated plastics through selective adsorption of wetting agents on plastic surface. The relationships between hydrophobic attraction and surface properties were also examined. It is revealed that there exists a three-order polynomial relationship between the AB Gibbs function and Lewis base component. Our finding provides some insights into mechanism of plastics flotation. PMID:26337962

  10. On the geophysical fingerprint of Vulcanian explosions

    NASA Astrophysics Data System (ADS)

    Gottsmann, J.; De Angelis, S.; Fournier, N.; Van Camp, M.; Sacks, S.; Linde, A.; Ripepe, M.

    2011-06-01

    Extrusion of viscous magma and the subsequent formation of a lava dome is often interspersed by short-lived vigorous (Vulcanian) explosions. The causes for and the timing of the transition from effusive to explosive activity during dome formation are poorly understood and forecasting this transition remains a challenge. Here, we describe and interpret a robust and unique multi-parameter data set documenting the subsurface processes associated with Vulcanian explosions at Soufrière Hills Volcano, Montserrat (W.I.) in July and December 2008. We quantify explosion priming by processes in either the shallow (< 2 km depth) or the deep magmatic system and quantify syn-eruptive processes. The July 29 explosion has a signature related exclusively to shallow dynamics including conduit destabilisation, syn-eruptive decompression and magma fragmentation, conduit emptying and expulsion of juvenile pumice. In contrast, the December 3 explosion was triggered by unprecedented sudden pressurisation of the entire plumbing system from depths of about 10 km (including the magma chambers) resulting in surficial dome carapace failure, a violent cannon-like explosion, propagation of pressure waves and pronounced ballistic ejection of dome fragments. With timescales for explosion priming on the order of a few minutes, the precursory geophysical signatures are indicative of the nature of ensuing Vulcanian explosions. The short precursory phases characterise Vulcanian explosions as freak events triggered by abrupt rather than gradual changes in subsurface dynamics. Our findings provide important constraints for theoretical and experimental investigations of the effusive to explosive transition, forecasting of Vulcanian explosions and volcanic risk mitigation.

  11. Air Activation Following an Atmospheric Explosion

    SciTech Connect

    Lowrey, Justin D.; McIntyre, Justin I.; Prichard, Andrew W.; Gesh, Christopher J.

    2013-03-13

    In addition to thermal radiation and fission products, nuclear explosions result in a very high flux of unfissioned neutrons. Within an atmospheric nuclear explosion, these neutrons can activate the various elemental components of natural air, potentially adding to the radioactive signature of the event as a whole. The goal of this work is to make an order-of-magnitude estimate of the total amount of air activation products that can result from an atmospheric nuclear explosion.

  12. Wireless sensor for detecting explosive material

    SciTech Connect

    Lamberti, Vincent E; Howell, Jr., Layton N; Mee, David K; Sepaniak, Michael J

    2014-10-28

    Disclosed is a sensor for detecting explosive devices. The sensor includes a ferromagnetic metal and a molecular recognition reagent coupled to the ferromagnetic metal. The molecular recognition reagent is operable to expand upon absorption of vapor from an explosive material such that the molecular recognition reagent changes a tensile stress upon the ferromagnetic metal. The explosive device is detected based on changes in the magnetic switching characteristics of the ferromagnetic metal caused by the tensile stress.

  13. Morphology and dynamics of explosive vents through cohesive rock formations

    NASA Astrophysics Data System (ADS)

    Galland, Olivier; Gisler, Galen R.; Haug, Øystein T.

    2015-04-01

    Shallow explosive volcanic processes, such as kimberlite volcanism, phreatomagmatic and phreatic activity, produce volcanic vents exhibiting a wide variety of morphologies, including vertical pipes and V-shaped vents. In this study we report on experimental and numerical models designed to capture a range of vent morphologies in an eruptive system (Galland et al., 2014). Using dimensional analysis, we identified key governing dimensionless parameters, in particular the gravitational stress-to-fluid pressure ratio (Π2=P/rho.g.h), and the fluid pressure-to-host rock strength ratio (Π3=P/C). We used combined experimental and numerical models to test the effects of these parameters. The experiments were used to test the effect of Π2 on vent morphology and dynamics. A phase diagram demonstrates a separation between two distinct morphologies, with vertical structures occurring at high values of Π2, and diagonal ones at low values of Π2. The numerical simulations were used to test the effect of Π3 on vent morphology and dynamics. In the numerical models we see three distinct morphologies: vertical pipes are produced at high values of Π3, diagonal pipes at low values of Π3, while horizontal sills are produced for intermediate values of Π3. Our results show that vertical pipes form by plasticity-dominated yielding for high-energy systems (high Π2 and Π3), whereas diagonal and horizontal vents dominantly form by fracturing for lower-energy systems (low Π2 and Π3). Although our models are 2-dimensionnal, they suggest that circular pipes result from plastic yielding of the host rock in a high-energy regime, whereas V-shaped volcanic vents result from fracturing of the host rock in lower-energy systems. Galland, O., Gisler, G.R., Haug, Ø.T., 2014. Morphology and dynamics of explosive vents through cohesive rock formations. J. Geophys. Res. 119, 10.1002/2014JB011050.

  14. Shock Initiation of Damaged Explosives

    SciTech Connect

    Chidester, S K; Vandersall, K S; Tarver, C M

    2009-10-22

    Explosive and propellant charges are subjected to various mechanical and thermal insults that can increase their sensitivity over the course of their lifetimes. To quantify this effect, shock initiation experiments were performed on mechanically and thermally damaged LX-04 (85% HMX, 15% Viton by weight) and PBX 9502 (95% TATB, 5% Kel-F by weight) to obtain in-situ manganin pressure gauge data and run distances to detonation at various shock pressures. We report the behavior of the HMX-based explosive LX-04 that was damaged mechanically by applying a compressive load of 600 psi for 20,000 cycles, thus creating many small narrow cracks, or by cutting wedge shaped parts that were then loosely reassembled, thus creating a few large cracks. The thermally damaged LX-04 charges were heated to 190 C for long enough for the beta to delta solid - solid phase transition to occur, and then cooled to ambient temperature. Mechanically damaged LX-04 exhibited only slightly increased shock sensitivity, while thermally damaged LX-04 was much more shock sensitive. Similarly, the insensitive explosive PBX 9502 was mechanically damaged using the same two techniques. Since PBX 9502 does not undergo a solid - solid phase transition but does undergo irreversible or 'rachet' growth when thermally cycled, thermal damage to PBX 9502 was induced by this procedure. As for LX-04, the thermally damaged PBX 9502 demonstrated a greater shock sensitivity than mechanically damaged PBX 9502. The Ignition and Growth reactive flow model calculated the increased sensitivities by igniting more damaged LX-04 and PBX 9502 near the shock front based on the measured densities (porosities) of the damaged charges.

  15. Explosion Welding for Hermetic Containerization

    NASA Technical Reports Server (NTRS)

    Dolgin, Benjamin; Sanok, Joseph

    2003-01-01

    A container designed for storing samples of hazardous material features a double wall, part of which is sacrificed during an explosion-welding process in which the container is sealed and transferred to a clean environment. The major advantage of this container sealing process is that once the samples have been sealed inside, the outer wall of what remains of the container is a clean surface that has not come into contact with the environment from which the samples were taken. Thus, there is no need to devise a decontamination process capable of mitigating all hazards that might be posed by unanticipated radioactive, chemical, and/or biological contamination of the outside of the container. The container sealing method was originally intended to be used to return samples from Mars to Earth, but it could also be used to store samples of hazardous materials, without the need to decontaminate its outer surface. The process stages are shown. In its initial double-wall form, the volume between the walls is isolated from the environment; in other words, the outer wall (which is later sacrificed) initially serves to protect the inner container from contamination. The sample is placed inside the container through an opening at one end, then the container is placed into a transfer dock/lid. The surfaces that will be welded together under the explosive have been coated with a soft metallic sacrificial layer. During the explosion, the sacrificial layer is ejected, and the container walls are welded together, creating a strong metallic seal. The inner container is released during the same event and enters the clean environment.

  16. Stellar Explosions: Hydrodynamics and Nucleosynthesis

    NASA Astrophysics Data System (ADS)

    José, Jordi

    2015-12-01

    Stars are the main factories of element production in the universe through a suite of complex and intertwined physical processes. Such stellar alchemy is driven by multiple nuclear interactions that through eons have transformed the pristine, metal-poor ashes leftover by the Big Bang into a cosmos with 100 distinct chemical species. The products of stellar nucleosynthesis frequently get mixed inside stars by convective transport or through hydrodynamic instabilities, and a fraction of them is eventually ejected into the interstellar medium, thus polluting the cosmos with gas and dust. The study of the physics of the stars and their role as nucleosynthesis factories owes much to cross-fertilization of different, somehow disconnected fields, ranging from observational astronomy, computational astrophysics, and cosmochemistry to experimental and theoretical nuclear physics. Few books have simultaneously addressed the multidisciplinary nature of this field in an engaging way suitable for students and young scientists. Providing the required multidisciplinary background in a coherent way has been the driving force for Stellar Explosions: Hydrodynamics and Nucleosynthesis. Written by a specialist in stellar astrophysics, this book presents a rigorous but accessible treatment of the physics of stellar explosions from a multidisciplinary perspective at the crossroads of computational astrophysics, observational astronomy, cosmochemistry, and nuclear physics. Basic concepts from all these different fields are applied to the study of classical and recurrent novae, type I and II supernovae, X-ray bursts and superbursts, and stellar mergers. The book shows how a multidisciplinary approach has been instrumental in our understanding of nucleosynthesis in stars, particularly during explosive events.

  17. Evaluation of surface storage facilities for explosives, blasting agents and other explosive materials

    NASA Astrophysics Data System (ADS)

    Roth, J.

    1983-06-01

    The histories of recent and past magazine explosions were reviewed; present explosive storage conditions and practices were observed; and existing Federal regulations on explosive storage were examined. A recent increase in magazine explosion frequency must be attributed to a large increase in deliberate explosions; fires of various origins account for the remaining explosions of the past decade. During 1884-1926 several lightning generated explosions occurred in nonmetal magazines. It appears that the contents of a well constructed metal magazine are immune to direct lightning strikes, regardless of whether the magazine is grounded or not. Grounding a metal magazine cannot be harmful, but it maywell be superfluous. Mine Safety and Health Administration and Bureau of Alcohol, Tobacco and Firearms standards on explosive storage appear to cover safety aspects adequately. Certain revisions are recommended to clarify some of the standards and to reduce inconsistencies in their enforcement.

  18. Power of TATP based explosives.

    PubMed

    Matyás, Robert; Selesovský, Jakub

    2009-06-15

    The power of various explosive mixtures based on triacetone triperoxide (3,3,6,6,9,9-hexamethyl-1,2,4,5,7,8-hexoxonane, TATP), ammonimum nitrate (AN), urea nitrate (UrN) and water (W), namely TATP/AN, oil/AN, TATP/UrN, TATP/W and TATP/AN/W, was studied using the ballistic mortar test. The ternary mixtures of TATP/AN/W have relatively high power in case of the low water contents. Their power decrease significantly with increasing the water content in the mixture to more than 30%. PMID:18995962

  19. Supernova Explosions Stay In Shape

    NASA Astrophysics Data System (ADS)

    2009-12-01

    At a very early age, children learn how to classify objects according to their shape. Now, new research suggests studying the shape of the aftermath of supernovas may allow astronomers to do the same. A new study of images from NASA's Chandra X-ray Observatory on supernova remnants - the debris from exploded stars - shows that the symmetry of the remnants, or lack thereof, reveals how the star exploded. This is an important discovery because it shows that the remnants retain information about how the star exploded even though hundreds or thousands of years have passed. "It's almost like the supernova remnants have a 'memory' of the original explosion," said Laura Lopez of the University of California at Santa Cruz, who led the study. "This is the first time anyone has systematically compared the shape of these remnants in X-rays in this way." Astronomers sort supernovas into several categories, or "types", based on properties observed days after the explosion and which reflect very different physical mechanisms that cause stars to explode. But, since observed remnants of supernovas are leftover from explosions that occurred long ago, other methods are needed to accurately classify the original supernovas. Lopez and colleagues focused on the relatively young supernova remnants that exhibited strong X-ray emission from silicon ejected by the explosion so as to rule out the effects of interstellar matter surrounding the explosion. Their analysis showed that the X-ray images of the ejecta can be used to identify the way the star exploded. The team studied 17 supernova remnants both in the Milky Way galaxy and a neighboring galaxy, the Large Magellanic Cloud. For each of these remnants there is independent information about the type of supernova involved, based not on the shape of the remnant but, for example, on the elements observed in it. The researchers found that one type of supernova explosion - the so-called Type Ia - left behind relatively symmetric, circular remnants. This type of supernova is thought to be caused by a thermonuclear explosion of a white dwarf, and is often used by astronomers as "standard candles" for measuring cosmic distances. On the other hand, the remnants tied to the "core-collapse" supernova explosions were distinctly more asymmetric. This type of supernova occurs when a very massive, young star collapses onto itself and then explodes. "If we can link supernova remnants with the type of explosion", said co-author Enrico Ramirez-Ruiz, also of University of California, Santa Cruz, "then we can use that information in theoretical models to really help us nail down the details of how the supernovas went off." Models of core-collapse supernovas must include a way to reproduce the asymmetries measured in this work and models of Type Ia supernovas must produce the symmetric, circular remnants that have been observed. Out of the 17 supernova remnants sampled, ten were classified as the core-collapse variety, while the remaining seven of them were classified as Type Ia. One of these, a remnant known as SNR 0548-70.4, was a bit of an "oddball". This one was considered a Type Ia based on its chemical abundances, but Lopez finds it has the asymmetry of a core-collapse remnant. "We do have one mysterious object, but we think that is probably a Type Ia with an unusual orientation to our line of sight," said Lopez. "But we'll definitely be looking at that one again." While the supernova remnants in the Lopez sample were taken from the Milky Way and its close neighbor, it is possible this technique could be extended to remnants at even greater distances. For example, large, bright supernova remnants in the galaxy M33 could be included in future studies to determine the types of supernova that generated them. The paper describing these results appeared in the November 20 issue of The Astrophysical Journal Letters. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. More information, including images and other multimedia, can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

  20. Overall characterization of cork dust explosion.

    PubMed

    Pilão, R; Ramalho, E; Pinho, C

    2006-05-20

    Explosibility and ignitability studies of air/cork dust mixtures were conducted in a near-spherical 22.7 L explosibility test chamber using pyrotechnic ignitors and in a furnace of 1.23 L. The suspension dust burned as air-dispersed dust clouds and the uniformity of the dispersion inside the chamber was evaluated through optical dust probes. The range of tested particle sizes went from a mass median diameter of 47.4 to 438.3 microm and the covered dust cloud concentration was up to 700-800 g/m(3). Measured explosion parameters included minimum explosible concentration, maximum explosion pressure, maximum rate of pressure rise and minimum autoignition temperature. The effect of dust particle size on flammability was evaluated and it was found that the minimum explosible concentration is around 40 g/m(3) and it is relatively independent of particle size below 180 microm. Maximum explosion pressure of 7.2 bar and maximum rate of pressure rise of 179 bar/s were detected for the smallest tested sizes. The limitations on the rates of devolatilization of the solid particles became rate controlling at high burning velocities, at high dust loadings and for large particle sizes. The effect of initial pressure on the characteristic parameters of the explosion was studied by varying the initial absolute pressure from 0.9 bar to 2.2 bar, and it was found that as initial pressure increases, there is a proportional increase of minimum explosion limit, maximum explosion pressure, and maximum rate of pressure rise. The influence of the intensity of the ignition energy on the development of the explosion was evaluated using ignition energies of 1000 J, 2500 J and 5000 J, and the experimental data showed that the value of 2500 J is the most convenient to use in the determination of minimum explosion concentration. The behavior of the cork dust explosion in hybrid methane air mixtures was studied for atmospheres with 2% and 3.5% (v/v) of methane. The effect of methane content on the characteristic parameters of the explosions was evaluated. The conclusion is that, the hazard and explosion danger rise with the increase of methane concentration, characterized by the reduction of the minimum dust explosion concentration. The minimum autoignition temperature obtained with the thermal ignition tests was 540 degrees C and the results have shown that this value is independent of particle size, for particles with mass median diameters below 80 microm. PMID:16297545

  1. Method and apparatus for detecting explosives

    DOEpatents

    Moore, David Steven

    2011-05-10

    A method and apparatus is provided for detecting explosives by thermal imaging. The explosive material is subjected to a high energy wave which can be either a sound wave or an electromagnetic wave which will initiate a chemical reaction in the explosive material which chemical reaction will produce heat. The heat is then sensed by a thermal imaging device which will provide a signal to a computing device which will alert a user of the apparatus to the possibility of an explosive device being present.

  2. Detecting explosive substances by the IR spectrography

    NASA Astrophysics Data System (ADS)

    Kuula, J.; Rinta, Heikki J.; Pölönen, I.; Puupponen, H.-H.; Haukkamäki, Marko; Teräväinen, T.

    2014-05-01

    Fast and safe detection methods of explosive substances are needed both before and after actualized explosions. This article presents an experiment of the detection of three selected explosives by the ATR FTIR spectrometer and by three different IR hyperspectral imaging devices. The IR spectrometers give accurate analyzing results, whereas hyperspectral imagers can detect and analyze desired samples without touching the unidentified target at all. In the controlled explosion experiment TNT, dynamite and PENO were at first analyzed as pure substances with the ATR FTIR spectrometer and with VNIR, SWIR and MWIR cameras. After three controlled explosions also the residues of TNT, dynamite and PENO were analyzed with the same IR devices. The experiments were performed in arctic outdoor conditions and the residues were collected on ten different surfaces. In the measurements the spectra of all three explosives were received as pure substances with all four IR devices. Also the explosion residues of TNT were found on cotton with the IR spectrometer and with VNIR, SWIR and MWIR hyperspectral imagers. All measurements were made directly on the test materials which had been placed on the explosion site and were collected for the analysis after each blast. Measurements were made with the IR spectrometer also on diluted sample. Although further tests are suggested, the results indicate that the IR spectrography is a potential detection method for explosive subjects, both as pure substances and as post-blast residues.

  3. Instrumentation advances in emissions characterization from propellant/explosive combustion

    SciTech Connect

    Einfeld, W.; Morrison, D.J.; Mullins, S.E.

    1995-12-31

    Results from a chamber study to characterize emissions from combustion of selected pure energetic materials are presented in this paper. The study was carried out as a part of a comprehensive air pathways risk assessment for a propellant and explosive manufacturing facility that engages in open burning methods for manufacturing waste disposal. Materials selected for emissions characterization in this study included both aluminized and non-aluminized composite propellant, a double base propellant and a plastic bonded explosive. Combustion tests in a specialized chamber revealed very low emissions for gaseous products of incomplete combustion such as carbon monoxide and nitrogen oxides. Analysis of gaseous and aerosol emission products for a pre-selected target analyte list that included both volatile and semi-volatile organics revealed either low or non-detectable emissions for the four energetic types tested. Hydrogen chloride was detected as a major emission product from propellants containing ammonium perchlorate. Results from this work reveal that about one-half of the chlorine in the original material is released as hydrogen chloride. Based on earlier work, the balance of the chlorine emissions is expected to be in the form of chlorine gas.

  4. An analysis of spectral differences between Nevada Test Site and Shagan River nuclear explosions

    NASA Astrophysics Data System (ADS)

    Taylor, Steven R.; Denny, Marvin D.

    1991-04-01

    Spectral ratio discrimination studies carried out on events located in the western United States and Soviet Union (S.U.) illustrate that pronounced differences in radiated explosion-source spectra relative to nearby earthquakes exist between the two regions. Nevada Test Site (NTS) explosions are characterized by the existence of more low-frequency and/or less high-frequency energy (greater low-to high-frequency spectral ratios) than western U.S. earthquakes. The opposite pattern is observed in the S.U. with nuclear explosions appearing to have more high-frequency (and/or less low-frequency) energy than earthquakes. These observations may be caused by at least two principal effects that are probably acting in parallel: (1) variations in depth-dependent effects of attenuation acting between the shallow explosions and deeper earthquakes and (2) differences in the dynamic response of the near-source geology to the passing explosion shock wave. Anelastic synthetic seismogram calculations illustrate that depth-dependent attenuation effects may explain the spectral observations. However, a number of observations using near- and far-field data from NTS explosions suggest that near-source effects are the dominant factor. A quasi-empirical explosion source model is proposed that simultaneously fits the spectral ratio data from both the U.S. and S.U. relative to earthquakes in each of the respective regions. Additionally, the model fits the trends of the spectral ratios observed as a function of magnitude. The key to the model is the shape of the pressure time history acting at the elastic radius. For explosions detonated in weak, porous rock, the radiated shock wave divides into a two-wave system consisting of an elastic precursor followed by a plastic wave. The generation of this two-wave system introduces a rise time into the pressure time history. In the frequency domain a second corner frequency is established in a third-order model (with an ω-3 high-frequency decay) whose value is inversely proportional to the time separation of the two waves. In higher-strength, saturated rocks (or for overburied explosions) the effective rise time is short, and a second-order model is appropriate (with an ω-2 high-frequency decay). The second-order model provides a good fit to the S.U. data. In contrast, a hybrid model is required to fit the NTS data with an ω-3 high-frequency decay for shallow explosions detonated in unsaturated tuff that evolves to an ω-2 decay as depth of burials reach higher-strength, saturated rocks below the water table.

  5. 27 CFR 70.445 - Commerce in explosives.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Cartridges, and Explosives § 70.445 Commerce in explosives. Part 55 of title 27 CFR contains the regulations... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Commerce in explosives. 70..., explosives, (b) Permits for users who buy or transport explosives in interstate or foreign commerce,...

  6. 27 CFR 70.445 - Commerce in explosives.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Cartridges, and Explosives § 70.445 Commerce in explosives. Part 555 of title 27 CFR contains the regulations... 27 Alcohol, Tobacco Products and Firearms 2 2012-04-01 2011-04-01 true Commerce in explosives. 70..., explosives, (b) Permits for users who buy or transport explosives in interstate or foreign commerce,...

  7. 27 CFR 70.445 - Commerce in explosives.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Cartridges, and Explosives § 70.445 Commerce in explosives. Part 555 of title 27 CFR contains the regulations... 27 Alcohol, Tobacco Products and Firearms 2 2013-04-01 2013-04-01 false Commerce in explosives. 70..., explosives, (b) Permits for users who buy or transport explosives in interstate or foreign commerce,...

  8. 27 CFR 70.445 - Commerce in explosives.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Cartridges, and Explosives § 70.445 Commerce in explosives. Part 555 of title 27 CFR contains the regulations... 27 Alcohol, Tobacco Products and Firearms 2 2014-04-01 2014-04-01 false Commerce in explosives. 70..., explosives, (b) Permits for users who buy or transport explosives in interstate or foreign commerce,...

  9. 27 CFR 70.445 - Commerce in explosives.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Cartridges, and Explosives § 70.445 Commerce in explosives. Part 555 of title 27 CFR contains the regulations... 27 Alcohol, Tobacco Products and Firearms 2 2011-04-01 2011-04-01 false Commerce in explosives. 70..., explosives, (b) Permits for users who buy or transport explosives in interstate or foreign commerce,...

  10. 27 CFR 555.63 - Explosives magazine changes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Explosives magazine..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Licenses and Permits § 555.63 Explosives magazine changes. (a) General. (1) The requirements of this section are...

  11. 27 CFR 555.28 - Stolen explosive materials.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Stolen explosive materials..., AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.28 Stolen explosive materials. No person shall receive, conceal, transport,...

  12. 27 CFR 555.23 - List of explosive materials.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true List of explosive materials..., AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.23 List of explosive materials. The Director shall compile a list of...

  13. 30 CFR 75.1310 - Explosives and blasting equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Explosives and blasting equipment. 75.1310... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only permissible explosives, approved sheathed explosive units,...

  14. 27 CFR 555.23 - List of explosive materials.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false List of explosive..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.23 List of explosive materials. The Director shall compile a list of...

  15. 27 CFR 555.23 - List of explosive materials.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false List of explosive..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.23 List of explosive materials. The Director shall compile a list of...

  16. 27 CFR 555.28 - Stolen explosive materials.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Stolen explosive materials..., AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.28 Stolen explosive materials. No person shall receive, conceal, transport,...

  17. 30 CFR 75.1310 - Explosives and blasting equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Explosives and blasting equipment. 75.1310... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only permissible explosives, approved sheathed explosive units,...

  18. 29 CFR 1926.903 - Underground transportation of explosives.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Underground transportation of explosives. 1926.903 Section... Explosives § 1926.903 Underground transportation of explosives. (a) All explosives or blasting agents in... explosives or blasting agents taken to an underground loading area shall not exceed the amount estimated...

  19. 27 CFR 555.63 - Explosives magazine changes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Explosives magazine changes..., AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Licenses and Permits § 555.63 Explosives magazine changes. (a) General. (1) The requirements of this section are applicable to...

  20. 29 CFR 1926.903 - Underground transportation of explosives.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Underground transportation of explosives. 1926.903 Section... Explosives § 1926.903 Underground transportation of explosives. (a) All explosives or blasting agents in... explosives or blasting agents taken to an underground loading area shall not exceed the amount estimated...